| Alberta Graduate Excellence ScholarshipThe Alberta Graduate Excellence Scholarship recognizes outstanding academic achievement of students pursuing graduate studies in Alberta. | Award | 2021-09-01 | Matthew Labbe |
| Alberta Graduate Excellence ScholarshipThe Alberta Graduate Excellence Scholarship recognizes outstanding academic achievement of students pursuing graduate studies in Alberta. | Award | 2019-09-01 | Thuy (Wendy) Nguyen Thanh Tran |
| Alberta Graduate Excellence ScholarshipThe Alberta Graduate Excellence Scholarship recognizes outstanding academic achievement of students pursuing graduate studies in Alberta. | Award | 2022-09-01 | Matthew Labbe |
| Captain Thomas Farrell Greenhalgh Memorial Graduate ScholarshipAwarded to graduate students in Chemical and Materials Engineering. | Award | 2021-09-01 | Matthew Labbe |
| D.B. Robinson Scholarship in Chemical and Materials EngineeringAwarded annually to two students of high academic standing who are registered full time in graduate degree programs in Chemical and Materials Engineering. Preference will be given to students studying in the field of Thermodynamics. | Award | 2020-09-01 | Matthew Labbe |
| D.B. Robinson Scholarship in Chemical and Materials EngineeringAwarded annually to two students of high academic standing who are registered full time in graduate degree programs in Chemical and Materials Engineering. Preference will be given to students studying in the field of Thermodynamics. | Award | 2017-09-01 | Ming Xiong |
| D.B. Robinson Scholarship in Chemical and Materials EngineeringAwarded annually to two students of high academic standing who are registered full time in graduate degree programs in Chemical and Materials Engineering. Preference will be given to students studying in the field of Thermodynamics. | Award | 2021-09-01 | Matthew Labbe |
| D.B. Robinson Scholarship in Chemical and Materials EngineeringAwarded annually to two students of high academic standing who are registered full time in graduate degree programs in Chemical and Materials Engineering. Preference will be given to students studying in the field of Thermodynamics. | Award | 2022-09-01 | Matthew Labbe |
| ECS Travel Grant for 241st ECS MeetingCompetitive travel award to attend and present at the ECS conference. | Award | 2022-05-29 | Hang Hu |
| ECS Travel Grant for 241st ECS MeetingCompetitive award to help fund travel to ECS conference. | Award | 2022-05-29 | Jiayao Cui |
| NSERC Canadian Graduate Scholarship – Doctoral (CGS-D)NSERC PhD Scholarship | Award | 2022-04-28 | Matthew Labbe |
| President's Doctoral Prize of DistinctionThe President's Doctoral Prize of Distinction (PDPD) is a Top-Up award that may be given to students registered full-time in a doctoral degree program at the University of Alberta who have won one of the eligible major doctoral-level scholarships | Award | 2022-05-01 | Matthew Labbe |
| President's Doctoral Prize of Distinction (PDPD)The PDPD is a top-up award that may be given to students registered full-time in a doctoral degree program at the UofA who have won one of the eligible major doctoral-level scholarships. | Award | 2023-05-01 | Matthew Labbe |
| W. Youdelis Graduate ScholarshipOne year award for September 2021 to August 2022 for "superior academic achievement" in Engineering. | Award | 2021-09-01 | Matthew Labbe |
| Energy Storage Flywheel Rotors - Mechanical Design University of Alberta | Publication | 2022-02-28 | Miles Skinner, Mertiny, P. |
| Additive Manufacturing of Magnetically Loaded Polymer Composites: An Experimental Study for Process DevelopmentMaterial jetting is an additive manufacturing technique that allows for the production of three-dimensional solid parts without tooling and with minimum material wastage. In this context, magnetically loaded polymer composites with oriented magnetic particles are promising for many electrical and electronic applications. In this study, permanent magnet based alignment configurations were evaluated and compared in terms of different magnetic flux density using the finite element method. The particle alignment in cured droplet specimens and the stability of magnetically loaded polymer droplets deposited on a substrate were characterized for a material jetting based additive manufacturing process. Particle alignment and droplet deformation under the influence of the magnetic field was captured using real-time optical microscopy. The influence of rheological additives in controlling droplet stability in the magnetic field and mitigating particle settling were studied through experiments. The primary goal of this research was to identify parameters that facilitate high particle alignment, and material combinations that enhance droplet stability and mitigate particle settling. This fundamental research serves to enhance the understanding of processes and material behaviour for material jetting based additive manufacturing. University of Alberta | Publication | 2017-11-03 | Balakrishnan Nagarajan, Mertiny, P. |
| Design Strategies for Flywheel Energy Storage Systems in EV Fast ChargingWith rising numbers of electric vehicles to curb greenhouse gas emissions, mitigating strain on the electrical grid from EV charging, specifically fast-charging applications, has become a significant challenge, especially since adapting grid infrastructure is not only complex but costly. Long service life, high power charge capacity, and the ability to mitigate peak loads to the electrical grid are some of the requirements for energy storage systems (ESS) to support electric vehicle fast charging. In this context, interest in flywheel energy storage systems (FESS) has been growing in recent years due to the favorable power characteristics and lack of cycle aging that FESS offer over electrochemical ESS such as second-life batteries. Typically, flywheel design has focused on small-scale transportation and large-scale grid frequency regulation applications. The present paper presents design strategies for FESS in fast-charging applications, which signifies a promising and innovative approach for reducing the strain that fast EV charging imposes on the electrical grid. This study considers design strategies to achieve low material and fabrication costs, a high safety standard, and operational advantages. University of Alberta | Publication | 2023-02-08 | Basaure Figueroa, F., Mertiny, P. |
| Enabling transdisciplinary education for energy systems transitions University of Alberta | Publication | 2020-01-01 | Miles Skinner, Anders, S., Mertiny, P. |
| Modeling and Simulation to Improve Real Electric Vehicles Charging Processes by Integration of Renewable Energies and Buffer Storage The present study explores a simulation model combining system dynamics and discrete-event simulation for an electric vehicle charging system. For the representation of the charging demand the model employs data from an actual facility for vehicle charging. While being connected to the electrical grid, the system is augmented by a solar photovoltaic installation and stationary battery energy storage. Multiple simulation runs were performed to analyze the considered energy system over a 1-year period and compare relevant output parameters for different system configurations and system locations. Results show that a solar photovoltaic installation can be effectively integrated. For the degree of self-sufficiency, high values of 87 % can be achieved with combined solar photovoltaic and battery energy storage systems.
© 2022 IEEE. University of Alberta | Publication | 2023-01-23 | Konstantin Sing, Mertiny, P., Marco Pruckner |
| An Investigation into the Charge Storage Mechanism for Mn2O3 as the Cathode Material in Zinc-ion Batteries240th Electrochemical Society Meeting, October 10 – 14, 2021 University of Alberta | Activity | 2021-10-10 | Qingping Hou, Ivey, D. |
| Atomic Layer Deposition of a Manganese-Iron Mixed Oxide as a Bifunctional Oxygen Catalyst for Zinc-Air BatteriesPRiME 2020, October 4-9, 2020 University of Alberta | Activity | 2020-10-04 | Matthew Labbe, Ivey, D. |
| Atomic Layer Deposition of Highly Stable Manganese-Iron Oxide Bifunctional Catalysts for Zinc-Air BatteriesAtomic layer deposition of manganese-iron oxide bifunctional catalysts for the air electrode for zinc-air batteries University of Alberta | Activity | 2022-05-31 | Matthew Labbe, Ken Cadien, Ivey, D. |
| Atomic Layer Deposition of Transition Metal Oxide Catalysts for Zinc-Air BatteriesTwitter poster and oral presentation as part of the FES Fall Symposium 2021. University of Alberta | Activity | 2021-09-14 | Matthew Labbe, Ken Cadien, Ivey, D. |
| Challenges in Zn-Air Battery Cell DesignConference presentation dealing will issues associated with design zinc-air batteries University of Alberta | Activity | 2024-05-24 | Matthew Labbe, Ivey, D. |
| Failure Analysis of Nickel-Coated Anodes in Zinc-Air Flow BatteriesAnalysis of failure of anodes for zinc-air reflow batteries. University of Alberta | Activity | 2022-05-29 | Hang Hu, Anqiang He, Drew Aasen, "Sheida Arfania", "Shantanu Shukla", Ivey, D. |
| Functional Electrolyte Additives for Zinc-Ion Batteries University of Alberta | Activity | 2024-05-24 | Jiayao Cui, Wang, X., Ivey, D. |
| Gel Polymer Electrolyte for Zinc-Air Batteries Operating at Low TemperaturesPoster presentation for FES Fall Symposium 2021 University of Alberta | Activity | 2021-09-17 | Jiayao Cui, Chung, H., Ivey, D. |
| Gel Polymer Electrolytes for Zinc-air Batteries Operating at Low TemperaturesGel polymers for use as the electrolyte for zinc-air batteries in applications at low temperatures. University of Alberta | Activity | 2022-05-24 | Jiayao Cui, Chung, H., Ivey, D. |
| Growth Behaviour of Iron Oxide using Atomic Layer DepositionPresentation dealing with modelling of atomic layer deposition of iron oxide for use as a catalyst for the air electrode in zinc-air batteries. University of Alberta | Activity | 2022-06-14 | Matthew Labbe, Ken Cadien, Ivey, D. |
| Microstructural Characterization of Nickel-Coated Anodes for Zinc-Air Flow BatteriesPresentation dealing with characterization of anodes for zinc-air reflow batteries. University of Alberta | Activity | 2022-06-14 | Hang Hu, Anqiang He, Drew Aasen, "Sheida Arfania", "Shatanu Shukla", Ivey, D. |
| Modified Gel Polymer Electrolytes for Zinc-Air Batteries Operating at Various TemperaturesPresentation dealing with gel polymers for application as the electrolyte in zinc-air batteries. University of Alberta | Activity | 2022-06-14 | Jiayao Cui, Chung, H., Ivey, D. |
| Transition Metal Oxides Anchored Onto Co-Doped Carbon Nanotubes As Bifunctional Electrocatalysts239th Electrochemical Society Meeting, May 30 – June 3, 2021 University of Alberta | Activity | 2021-05-30 | Alexandra McDougall, Ivey, D. |
| Zinc and Nickel Based Oxides Anchored Onto Nitrogen-Doped Nanotubes As Bifunctional Catalysts for Zinc-Air BatteriesPRiME 2020, October 4-9, 2020 University of Alberta | Activity | 2020-10-04 | Alexandra McDougall, Ivey, D. |
| Zinc-Air Battery Advances: Efficiency, Stability, and Low Temperature OperationPoster presentation on progress in Ivey Group on zinc-air batteries. University of Alberta | Activity | 2023-04-28 | Jiayao Cui, Matthew Labbe, "Zahra Abedi", Chung, H., Ken Cadien, Ivey, D. |
| Zinc-philic Electrolyte Additives for Zinc-Ion Batteries University of Alberta | Activity | 2024-05-22 | Jiayao Cui, Wang, X., Ivey, D. |
| Atomic Layer Deposition of Metal Oxides for the Preparation of High Performance Zn-Air Battery ElectrodesAs the world continues to implement renewable energy technologies such as wind and solar, comes the demand for grid scale energy storage. Zn-air batteries (ZABs) are a promising candidate for grid scale energy storage because of their high energy density, low cost, high safety, and low environmental impact. Current generation ZABs, however, suffer from poor efficiency due to the sluggish kinetics at the air electrode. Despite their excellent activity, noble metal catalysts such as Pt are far too expensive for widespread use; this has driven the development of inexpensive transition metal oxide (TMO) catalysts. Due to their poor electrical conductivity, TMOs are typically nanostructured and/ or mounted on a conductive support.
Atomic layer deposition (ALD) is a thin film fabrication technique capable of producing highly conformal films of a wide range of materials. Because of the highly uniform and conformal nature of ALD films, ALD is particularly well suited for coating of highly porous structures such as the air electrode used in ZABs. The purpose of this work is to develop a process to prepare high performance ZAB air electrodes by depositing MnOx directly into the porosity of the air electrode by ALD.
The first study in this work included a thorough study of the saturation behaviour of bis(ethylcyclopentadienyl) manganese ((EtCp)2Mn) and water, with and without a forming gas (FG) (5% H2, 95% N2) plasma step. Contrary to previously published literature, the deposition using only (EtCp)2Mn and water (W-MnOx) did not experience saturating reactions; this deposition did not follow an ALD mechanism. A saturating ALD mechanism was achieved for depositions that used a FG plasma step between the (EtCp)2Mn and water doses (FG-MnOx), resulting in a growth per cycle of 1.15 Å/cy within the temperature range of 100 – 200 °C. Porous carbon electrodes were coated with MnOx following both recipes. Scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDX) line scans of electrode cross sections showed that the saturating mechanism FG-MnOx resulted in deposition deeper within the porosity than the W-MnOx. Electrochemical testing showed that the FG-MnOx also had improved electrochemical surface area as well as activity towards the oxygen reduction reaction; this is attributed to the better porosity coverage of FG-MnOx over W-MnOx.
The second study in this work involved the preparation and testing of MnOx coated electrodes in a full cell ZAB. Three types of electrodes were prepared in this work, FG-MnOx, FG-MnOx + CoOx, and O2-MnOx. FG-MnOx was prepared using the same procedure used in the first study and the FG-MnOx + CoOx sample was prepared by depositing CVD CoOx on top of FG-MnOx. O2-MnOx was prepared using an oxygen plasma and did not follow a saturating deposition mechanism. Scanning transmission electron microscopy (STEM) revealed that the gas diffusion layer (GDL) particles were successfully coated with a uniform layer of MnOx. Electron diffraction and x-ray photoelectron spectroscopy (XPS) were used to identify FG-MnOx and O2-MnOx as hausmannite, Mn3O4. Full cell ZAB tests showed excellent performance for MnOx-2 coated electrodes, out performing Pt/Ru-C at current densities larger than 100 mA cm-2. FG-MnOx and O2-MnOx electrodes had maximum power densities of 170 and 184 mW cm-2, respectively. With the catalyst distributed within the structure of the GDL, performance limitations associated with electrolyte flooding and air diffusion are reduced, improving discharge potential and cycling behavior. FG-MnOx + CoOx electrodes showed good cycling stability, both in a tri-electrode configuration and bifunctionally. When cycled at 20 mA cm-2 for 100 h (200 cycles), FG-MnOx + CoOx had initial and final discharge potentials of 1.18 and 1.15 V, respectively. | Publication | 2020-02-25 | Michael Clark |
| Development and characterization of magnetic particle reinforced polymers for additive manufacturing processesAdditive manufacturing enables the production of complex parts with less tooling and minimum material wastage. Polymer composites with magnetic functionality are promising for many applications like sensors, non-contact actuators and permanent magnets for electromechanical devices. The primary goal of this research work is to develop magnetic particle reinforced polymers and engineer additive manufacturing processes for manufacturing magnetic field responsive composites and permanent magnets involving hard ferrites and critical rare earth materials. Two different additive manufacturing techniques namely, stereolithography and material jetting were utilized to manufacture both isotropic and anisotropic magnetic composites. Irrespective of the additive manufacturing technique, developing magnetic polymer formulations that offer synergistic properties are a prerequisite for developing composites with engineered properties. The research study is broadly classified into four sections. The first section deals with the manufacture of isotropic magnetic field responsive composites using a stereolithography process. A commercial 3D printer with the capability of printing UV curable resins was utilized. Adopting a structured experimental framework, the curing behavior of magnetic particle reinforced formulations and dimensional variability in printed magnetic composites were evaluated. It was observed that characteristics of 3D printed magnetic structures depend on the formulation materials, 3D printing equipment and the process parameters. The second section of the study deals with the manufacture of field structured magnetic composites using material jetting additive manufacturing process. The finite element method in magnetics was used to develop permanent magnet-based particle alignment fixtures to orient ferromagnetic particles during the printing process. Directionality analysis using microscopic images was conducted to evaluate the orientation angle and count of oriented structures at specific orientation angles. Fundamental work carried out in this section enabled the development of a 3D printer with magnetic particle alignment capability. Ferromagnetic particle reinforced formulations were engineered to exhibit enhancement in low shear viscosity and time dependent viscosity recovery that enabled control of particle aggregation, particle chaining and control of microstructure distortions in the UV curable polymers. X-Ray diffraction technique was used to identify the orientation of the easy axis of magnetization in anisotropic specimens. Magnetic characterization conducted on field-structured composites exhibited enhanced magnetic characteristics along the direction of field structuring. The third section of the study entailed the manufacture of permanent magnets using magnetic particles and additive reinforced epoxy resin formulations. Modifications in rheological behavior of polymer formulations was achieved adopting multimodal magnetic particle mixtures and additive materials. Control of particle settling, modifications in rheological behavior and geometric stability were accomplished using an additive that enabled controlling the formulation behavior at different process conditions. The characterization of magnetic polymers and composites using rheometry, scanning electron microscopy, X-ray diffraction and magnetometry analyses enabled correlating of the behavior observed in different stages of the manufacturing processes. In the fourth section of the study, an acrylate based UV curable photopolymer was engineered for additional thermal cure, and permanent magnets with a filler loading of up to 80 wt% were printed using the engineered formulation. Overall, this research work broadens the capabilities for manufacturing magnetic composites with properties tailored for a multitude of engineering applications and provides a framework to understand to role of engineering material formulations to suit a wide range of processing conditions and requirements. | Publication | 2021-07-15 | Balakrishnan Nagarajan |
| Electrodeposited Electrocatalysts For Rechargeable Zinc-air Batteries
Electrically rechargeable zinc-air (Zn-air) batteries have gained renewed interest among the various technologies available with their high theoretical energy density and low cost. However, large-scale industrial deployment of Zn-air batteries is limited by several issues; the most concerning of these are low round-trip energy efficiency and performance degradation. Both problems are intimately related to the low activity and stability of electrocatalysts at the air electrode for catalyzing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Many transition metal-based catalysts have been developed to replace precious metal catalysts. However, most of them require complex procedures to fabricate and need to be mixed with additives to work as electrodes. These processes can add extra cost and are difficult to scale- up. Therefore, a simple way to prepare air electrodes with active catalysts is desired.
The purpose of this work was to electrodeposit transition metal (Co, Fe, Mn) based ORR/OER active catalysts on a gas diffusion layer (GDL) as the air electrode of Zn-air batteries. The as- deposited samples were characterized by several techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties were investigated by a variety of electrochemical tests, such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Samples with the best performance were assembled into a home-made Zn-air battery for further evaluation. | Publication | 2018-06-12 | Ming Xiong |
| Gel Polymer Electrolytes and Battery Designs for Rechargeable Zinc-Air Batteries | Publication | 2020-05-31 | Thuy (Wendy) Nguyen Thanh Tran |
| Investigation of Failure Modes of Fiber Reinforced Polymer Composite Flywheel Rotors for Energy Storage Systems | Publication | 2022-09-30 | Miles Skinner |
| Bringing down the cost of zinc-air batteries could unlock their full potential for storing renewable energyA doctoral candidate in engineering at the U of A is working to improve the affordability and feasibility of a zinc-air battery that could potentially be widely used to store solar energy. | Activity | 2022-05-04 | Matthew Labbe |
| Characterization of Electroless Ni-P Coatings and Electrodeposition of Ni Coatings for Electrodes in Zinc-Air Flow BatteriesMSc thesis | Publication | 2023-05-08 | Hang Hu |
| Design and Multi-Objective Optimization of Fiber-Reinforced Polymer Composite Flywheel RotorsA multi-objective optimization strategy to find optimal designs of composite multi-rim flywheel rotors is presented. Flywheel energy storage systems have been expanding into mobile applications, where the construction volume is limited. Common flywheel rotor optimization approaches for these applications are single-objective, aiming to increase the stored energy or stored energy density. The proposed multi-objective optimization offers more information for decision-makers optimizing three objectives separately: stored energy, cost and productivity. A novel approach to model the manufacturing of multi-rim composite rotors facilitates the consideration of manufacturing cost and time within the optimization. An analytical stress calculation for multi-rim rotors was implemented, which also takes interference fits and residual stresses into account. Constrained by a failure prediction based on the Maximum Strength, Maximum Strain and the Tsai-Wu criterion, a discrete and nonlinear optimization problem was solved. A hybrid optimization strategy is presented that combines a genetic algorithm with a local improvement executed by a sequential quadratic program. The problem was solved for several rotor geometries showing that manufacturing costs constitute the main cost-driver for small-scale flywheels. Analyzing the influence of several optimization parameters has shown that optimization results strongly depend on the applied failure criteria and material properties. | Publication | 2018-03-12 | Marvin Mittelstedt |
| Gas Diffusion Layers Impregnated with Metal Oxide Decorated and Nitrogen-Doped Carbon Nanotube Catalysts for Electrically Rechargeable Zn-Air BatteriesSecondary zinc-air batteries (ZABs) have garnered interest in recent years as a promising technology for energy storage due to their minimal safety concerns, low cost, and a high theoretical energy density. However, many issues still need to be resolved for commercialization of ZABs. Many of these issues are associated with the air electrode, such as the slow kinetics of the oxygen reduction and oxygen evolution reactions (ORR and OER, respectively) and poor cycle life. The former has been addressed previously through the use of noble metal catalysts such as Pt, Ru, and Ir, as well as their oxides. However, these catalysts are expensive and suffer from performance degradation during battery cycling. Additionally, the catalyst is often applied to the electrode as a layer on the surface which is susceptible to a phenomenon known as flooding. As the battery is cycled, electrolyte will flood the electrode and pass through the catalyst layer, resulting in performance losses. Therefore, development of low-cost catalysts and a simple electrode preparation technique to help mitigate the effects of flooding is desired.
This work focusses on the development of impregnated air electrodes using transition metal (Mn, Co, Fe, and Ni) oxide decorated, nitrogen-doped carbon nanotube (N-CNT) catalysts to improve the performance and cycling efficiency of ZABs. The effect of the impregnation technique as a form of electrode preparation was investigated through cross sectional scanning electron microscopy (SEM) and electrochemical tests such as galvanostatic charge and discharge rate tests (battery rate tests), as well as linear sweep voltammetry (LSV). The N-CNT supported catalysts were characterized using SEM, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the catalysts was evaluated using cyclic voltammetry (CV), LSV, electrical impedance spectroscopy (EIS), and battery rate tests. The best performing samples were then selected for use in an electrically rechargeable ZAB.
The first study involved the impregnation and synthesis of air electrodes using Mn3O4 decorated N-CNT catalysts for ORR. The catalysts were prepared using a simple precipitation method. The air electrode was simultaneously impregnated with the catalysts during synthesis through soaking and vacuum filtration. The impregnated electrode showed superior performance to electrodes prepared by conventional spray coating. Furthermore, the Mn3O4/N-CNT impregnated electrodes had superior ORR performance to other Mn3O4 catalysts from the literature, as well as similar ORR performance to commercially available Pt-Ru/C catalysts. The electrode was coupled with electrodeposited Co-Fe on Ni foam and was cycled in a tri-electrode cell. The tri-electrode cycling performance was comparable to that of Pt-Ru/C under the same tri-electrode cycling conditions.
The second study involved the preparation of bimetallic (Co,Fe)3O4 decorated N-CNTs as a bifunctional and highly stable catalyst for ZABs. The catalyst and electrode preparation were achieved again by simultaneous precipitation and impregnation. Characterization through TEM and XPS indicated mixed valence for both Co and Fe in a spinel oxide phase. Electrochemical testing of the (Co,Fe)3O4/N-CNT impregnated electrodes showed comparable ORR activity and superior OER activity to Pt-Ru/C at 20 mA cm . Bifunctional cycling of (Co,Fe)3O4/N-CNT at a
current density of 10 mA cm-2 exhibited exceptional stability with a discharge/charge efficiency of 58.5% after 200 cycles (100 h), which compared favorably with Pt-Ru/C under the same conditions (55.3% after 200 cycles).
The third study investigated the catalytic performance of transition metal based bimetallic and trimetallic oxides on N-CNTs for ZABs. Using the developed synthesis and impregnation technique, 6 bimetallic oxides (Mn-Co, Co-Fe, Mn-Fe, Ni-Co, Ni-Fe, Ni-Mn) and 3 trimetallic oxides (Ni-Co-Fe, Ni-Mn-Fe, Mn-Co-Fe) were synthesized on N-CNTs. All catalysts were characterized through TEM and SEM analysis. The trimetallic oxide catalysts were further
characterized through XPS analysis and were determined to exist as various spinel phases. Ni-Mn oxide on N-CNTs (NiMnOx/N-CNT) had the best ORR performance of the bimetallic oxides, while Ni-Fe oxide on N-CNTs (NiFeOx/N-CNT) and (Co,Fe)3O4/N-CNT had the best OER performance and bifunctional performance, respectively. The trimetallic oxide systems were selected based on the battery rate test performance and discharge/charge efficiencies of the bimetallic oxide catalysts. Electrochemical testing of the trimetallic oxides on N-CNTs showed improved activity towards OER when compared with the bimetallic oxides. Furthermore, the trimetallic oxides had similar ORR performance to Pt-Ru/C and superior OER performance in battery rate tests. Bifunctional cycling of the trimetallic oxide catalysts showed good cycling stability and superior efficiencies to Pt-Ru/C after 200 cycles (100 h) at a current density of 10 mA-2 cm . Ni-Co-Fe oxide on N-CNTs (NCFO/N-CNTs) had the best cycling performance of the trimetallic oxide catalysts and the best OER activity of all 10 catalysts tested in the study. Bifunctional cycling of NCFO/N-CNT at a current density of 20 mA cm-2 demonstrated better cycling efficiency than Pt-Ru/C after 100 cycles (53.2% vs 41.3%, respectively). | Publication | 2019-11-12 | Drew Aasen |
| Low-Temperature Tolerant Gel Polymer Electrolytes for Rechargeable Zn-Air BatteriesMSc thesis | Publication | 2022-12-22 | Jiayao Cui |
| Techno-economic Feasibility of Flywheel Energy Storage System in Standalone and Hybrid Applications | Publication | 2021-09-30 | Muhammad Saad Arshad |
| Transition Metal Oxides Anchored onto Heteroatom Doped Carbon Nanotubes as Efficient Bifunctional Catalysts for Rechargeable Zinc-Air BatteriesThis work focuses on further investigating a previously developed impregnation technique for air electrode preparation using an array of transition metal (Zn, Ni, Mn, and Co) oxide combinations. Various electrochemical and microstructural characterization techniques, e.g., linear sweep voltammetry, electrochemical impedance spectroscopy, electron microscopy, and energy dispersive X-ray spectroscopy, are used to examine each sample.
| Publication | 2021-09-29 | Alexandra McDougall |
| Front Cover: Hollow Mesoporous Carbon Nanospheres Decorated with Metal Oxide Nanoparticles as Efficient Earth-Abundant Zinc-Air Battery CatalystsThe Front Cover shows an artistic representation of a new class of bifunctional zinc‐air battery catalysts that consist of hollow mesoporous carbon nanospheres decorated with various precious‐metal‐free transition‐metal oxide nanoparticles. University of Alberta | Publication | 2021-03-22 | Yingjie He, Drew Aasen, Alexandra McDougall, Haoyang Yu, Matthew Labbe, Chuyi Ni, Sarah Milliken, Ivey, D., Jonathan GC Veinot |
| Zinc-Air Batteries: The Search for Better RustPresentation to the University of Alberta Senate on the use of iron oxide as a catalyst for the air electrode in zinc-air batteries. | Activity | 2023-03-03 | Matthew Labbe |
| Sequentially Electrodeposited MnOX/Co-Fe as Bifunctional Electrocatalysts for Rechargeable Zinc-Air BatteriesManganese oxide (MnOx) and cobalt-iron (Co-Fe) were sequentially electrodeposited onto a gas diffusion layer (GDL) as bifunctional electrocatalysts for rechargeable zinc-air batteries. The fabricated material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The sequentially deposited MnOx/Co-Fe catalysts, tested using cyclic voltammetry (CV), showed activity for both the oxygen reduction and oxygen evolution reactions (ORR and OER), with better performance than either MnOx or Co-Fe alone. The fabricated material was assembled into a zinc-air battery as the air electrode component for battery cycling tests. The zinc-air battery using MnOx/Co-Fe catalysts exhibited good discharge-recharge performance and a cycling efficiency of 59.6% at 5 mA cm−2, which is comparable to Pt/C catalysts. In addition, the electrodeposited MnOx/Co-Fe layer showed strong adhesion to the gas diffusion layer (GDL) and was structurally stable throughout 40 h of battery cycling. University of Alberta | Publication | 2017-03-17 | Ming Xiong, Ivey, D. |
| (Co,Fe)3O4 Decorated Nitrogen‐Doped Carbon Nanotubes in Nano‐Composite Gas Diffusion Layers as Highly Stable Bifunctional Catalysts for Rechargeable Zinc‐Air Batteries(Co,Fe)3O4 nanoparticles are decorated onto N‐doped carbon nanotubes at room temperature through a simple mixing process and are simultaneously deposited within a porous gas diffusion layer (GDL) by an impregnation technique. The (Co,Fe)3O4 nanoparticles are identified as the spinel phase through transmission electron microscopy (TEM) and X‐ray photoelectron spectroscopy (XPS) analysis. The composite GDL is used as the air electrode for Zn‐air batteries and shows excellent performance as a bifunctional catalyst with initial discharge and charge potentials of 1.19 V and 2.00 V, respectively, at 20 mA cm−2. Cycling performance of the impregnated electrode compares favourably with benchmark Pt‐RuO2 catalysts at both 10 mA cm−2 and 20 mA cm−2. The (Co,Fe)3O4/N‐CNT impregnated GDL had a final discharge/charge efficiency of 58.5 % after 100 h (200 cycles) of bifunctional cycling at 10 mA cm−2, which is superior to that of Pt‐RuO2 (55.3 % efficiency). The cycling efficiency for (Co,Fe)3O4/N‐CNT impregnated GDL at 20 mA cm−2 is also better than that for Pt−Ru (53.5 % vs 41.3 % after 50 h (100 cycles)). The result is a simple and easily scalable one‐pot electrode synthesis method for high performing bi‐functional air electrodes for Zn‐air batteries. University of Alberta | Publication | 2019-11-19 | Drew Aasen, Michael Clark, Ivey, D. |
| A Gas Diffusion Layer Impregnated with Mn3O4 Decorated, Nitrogen-Doped Carbon Nanotubes for High Performance Zinc-Air BatteriesMn3O4 decorated N-CNTs are synthesized and impregnated into porous carbon paper (gas diffusion layer or GDL) to form a composite catalyst-GDL material in a simple and novel one-pot process. The impregnated electrode features high active surface area, improved discharge performance and reduced vulnerability to flooding when compared with other electrode preparation techniques for similar catalysts. Electrochemical and battery testing show catalytic activity and a maximum discharge potential superior to other CNT supported Mn3O4 catalysts, and comparable to commercially used Pt-Ru (1.21 V at 20 mA cm-2). The composite is cycled at 10 mA cm-2 and 20 mA cm-2 as a bifunctional catalyst and as an ORR exclusive catalyst, respectively. Discharge performance is stable over 200 cycles at 20 mA cm-2 when used exclusively for ORR with a discharge-charge efficiency superior to Pt-Ru when coupled with electrodeposited Co-Fe as the OER catalyst (efficiency of 59% after cycling). University of Alberta | Publication | 2019-11-05 | Drew Aasen, Michael Clark, Ivey, D. |
| A Horizontal Zinc-air Battery with Physically Decoupled Oxygen Evolution/Reduction Reaction ElectrodesA horizontal Zn-air battery has been designed to enable the use of physically decoupled and catalytically efficient ORR and OER electrodes for discharge and charge, respectively. The horizontal design features a horizontally positioned ORR electrode and a vertically positioned OER electrode, allowing effective management of oxygen transport and pressure. The ORR catalyst (MnOx) and OER catalyst (Co-Fe alloy) are fabricated via one-step electrodeposition on carbon paper and Ni foam, respectively. MnOx is identified as a combination of Mn3O4 nanorods and α-Mn2O3 spheres. Co-Fe is deposited as a solid solution film with an oxidized surface. Electrochemical tests show that both catalysts have comparable or even better activity than their commercial Pt- Ru catalyst counterpart. The catalysts are cycled at 20 mA cm−2 to examine their durability. Cycling potential affects catalyst durability, with improved lifetime under separate ORR and OER conditions compared with the full ORR-OER voltage range. The fabricated catalysts are assembled into a Zn-air battery for discharge-charge cycling tests and show the same average efficiency (58%) as commercial Pt-Ru catalysts. University of Alberta | Publication | 2018-05-24 | Ming Xiong, Michael Clark, Matthew Labbe, Ivey, D. |
| A Study of Alkaline Gel Polymer Electrolytes for Rechargeable Zinc-Air BatteriesIn this report, hydrated hydrogels are investigated for application in rechargeable zinc-air batteries (ZABs) based on their ionic conductivities, chemical stability, electrochemical windows and mechanical properties. Three different hydrogel networks, i.e., poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(4- vinylbenzenesulfonate-co-[3-(methacryloylamino)propyl]trimethylammonium chloride) (PAM), were chosen based on their chemical composition and network electrical charge difference. Since the hydrogel network affects electrolyte uptake, which in turn may influence conductivity, understanding the correlation between hydrogel species and ionic conductivity provides insight into designing an appropriate gel polymer electrolyte (GPE) for ZABs. The relationship between ionic conductivity, water uptake and temperature are discussed. In ZAB cycling tests, although GPEs have a higher bulk resistance than aqueous electrolytes, they have lower interfacial and charge transfer resistances. The total resistance values for PVA and PAA, with 6 M KOH, vary from 4 - 6 Ω, which are lower than the values for KOH solution (~11 Ω) and PAM with 6 M KOH (~14 Ω). As such, this study demonstrates that GPEs show considerable promise for use as electrolytes in ZABs. University of Alberta | Publication | 2019-12-10 | Thuy (Wendy) Nguyen Thanh Tran, Chung, H., Ivey, D. |
| A Tri–Electrode Configuration for Zinc–Air Batteries Using Gel Polymer ElectrolytesTo increase the cyclability of rechargeable zinc–air batteries (ZABs) using gel polymer electrolytes (GPEs), battery design and structure need to be optimized. Two different configurations for a tri–electrode battery have been developed in this work; i.e., a planar cell and a sandwich cell. Discharge–recharge cycling tests at 5 mA cm–2 show that the sandwich cell is more suitable for ZABs than the planar cell. Various additives for the GPEs, such as cross linking agents and ZnO, have also been evaluated using the tri–electrode design. Cross linking density affects the physical state of GPEs, which in turn affects the oxygen evolution reaction as there is an adverse effect of excessive GPE/Ni foam electrode contact area because oxygen bubble may be trapped in the GPE. The addition of ZnO to the oxygen reduction reaction side of the battery enhances the cycling performance of ZABs; i.e., the battery can withstand at least 100 cycles at 5 mA cm–2 with an efficiency of 62% during the first cycle. University of Alberta | Publication | 2020-01-24 | Thuy (Wendy) Nguyen Thanh Tran, Ming Xiong, Michael Clark, Chung, H., Ivey, D. |
| Additive manufacturing ferromagnetic polymers using stereolithography – Materials and process developmentMagnetic field responsive polymer composites find applications in many electrical and electronic devices. In this study, composites with magnetic fillers were manufactured using a stereolithography based AM process. Magnetic suspensions developed with an objective of controlling particle settling were characterized for rheological properties. A stereolithography based commercial 3D printer was utilized to fabricate components using the developed magnetic suspensions. Resulting magnetic composite structures were characterized using scanning electron microscopy, a coordinate measuring machine and Fourier transform infrared spectroscopy. Through this research an enhanced understanding of filler modified polymers development, material behaviour and the process for manufacturing magnetic field responsive composites using stereolithography is obtained. University of Alberta | Publication | 2019-08-01 | Balakrishnan Nagarajan, Muhammad Arshad, Ullah, A., Mertiny, P., Qureshi, A. |
| An Investigation into the Charge Storage Mechanism and Cycling Performance of Mn2O3 as the Cathode Material for Zinc-ion BatteriesHighly crystalline, nanosize Mn 2 O 3 powder is synthesized via a precipitation and calcination method for utilization as the cathode in aqueous zinc-ion batteries (aZIBs). The resultant electrodes are characterized using electrochemical and microstructural methods to determine the mechanisms associated with charge and discharge. In addition, quantitative methods are used to investigate cycling performance stability. A specific capacity of 211 mAh g -1 is retained after 200 cycles at a current density of 500 mA g -1 with 93% capacity retention. Also, 73% capacity retention can be reached after 1100 cycles at a current density of 2000 mA g -1 . The energy storage mechanism associated with Mn 2 O 3 is, for the first time, proposed to be a chemical conversion reaction type with two steps involving the formation/decomposition of ZnMn 2 O 4 (hetaerolite) and zinc sulphate hydroxide (ZHS). Also, capacity fading is directly linked to the incomplete reversibility of the chemical conversion reaction. University of Alberta | Publication | 2022-05-01 | Qingping Hou, Ivey, D. |
| Atomic Layer Deposition of Iron Oxide on a Porous Carbon Substrate via Ethylferrocene and an Oxygen PlasmaEthylferrocene, a novel precursor for atomic layer deposition (ALD) of iron oxide, was investigated using an oxygen plasma co-reactant. Iron oxide deposition showed a saturating growth rate of 0.1 Å/cycle in the temperature range of 150°C to 250°C. The iron oxide coating was subsequently deposited on a porous gas diffusion layer (GDL) for use as an air electrode in a zinc-air battery. X-ray microanalysis confirmed deep penetration of the iron oxide into the porosity of the GDL, with a lower substrate temperature providing deeper coverage. Transmission electron microscopy revealed that a uniform 10 nm thick iron oxide coating encased the GDL particles. Electron diffraction and X-ray photoelectron spectroscopy identified the iron oxide film as -Fe2O3. Electrochemical characterization of the ALD-coated GDL showcased promising catalytic activity towards the oxygen evolution reaction. University of Alberta | Publication | 2021-09-15 | Matthew Labbe, Michael Clark, "Zahra Abedi", Anqiang He, Ken Cadien, Ivey, D. |
| Bifunctional Mn-Fe Oxide Catalysts for Zn-Air Battery Air Electrodes Fabricated Through Atomic Layer DepositionZinc-air batteries (ZABs) are one of many energy storage technologies that can help integrate renewable energy into the power grid. A key developmental goal for ZABs is replacing the precious metal catalysts at the air electrode with more abundant and inexpensive materials. In this work, a MnFexOy bifunctional catalyst is directly deposited on a ZAB air electrode using atomic layer deposition (ALD). With ALD, the atomic composition of the air electrode coating can be finely tuned based on catalytic activity. Characterization through electron microscopy, photoelectron spectroscopy and diffraction techniques indicate that the novel ALD film deposits as a nanocrystalline (Mn,Fe)3O4 cubic spinel. The mixed oxide catalyst outperforms its individual binary MnOx or FeOx constituents, operating at 50.7% bifunctional efficiency at 20 mA cm-2. Moreover, the long term stability of the ALD catalyst is showcased by 600 h (1565 cycles) of ZAB cycling at 10 mA cm-2. The efficiency retention of the bifunctional transition metal oxide catalyst is superior to a precious metal benchmark of Pt-Ru-C, with 84.7% efficiency retention after more than 1500 cycles versus only 66.2% retention for the precious metal catalyst. The ALD technique enables deep penetration of catalyst material into the air electrode structure, improving the cycling behaviour. University of Alberta | Publication | 2024-05-22 | Matthew Labbe, Michael Clark, Ken Cadien, Ivey, D. |
| Catalyst Integration within the Air Electrode in Secondary Zn-air BatteriesThe air electrode of a Zn-air battery facilitates the O2 reduction and evolution reactions during battery discharge and charge, respectively. These reactions are kinetically sluggish and appropriate catalysts are essential at the air electrode to increase battery efficiency. Precious metals are traditionally used, but increasingly attention has shifted towards non-precious metal catalysts to decrease the cost and increase the practicality of Zn-air batteries. However, loading of the catalyst onto the air electrode is equally as important as catalyst selection. Several methods can be used to deposit catalysts, each with their own advantages and disadvantages. Example methods include spray-coating, electrodeposition, and impregnation. These can be categorized as indirect, direct, and hybrid catalyst loading techniques, respectively. Direct and hybrid loading methods generally provide better depth of loading than indirect methods, which is an important consideration for the porous, air-breathing electrode of a Zn-air battery. Furthermore, direct methods are free from ancillary materials such as a binder, required by indirect and hybrid methods, which translates into better cycling stability. This review examines the various techniques for fabricating catalyst-enhanced air electrodes with an emphasis on their contributions to battery performance and durability. More durable Zn-air battery air electrodes directly translate to longer operational lifetimes for practical Zn-air batteries, which is an important consideration for the future implementation of electrochemical energy storage in energy systems and technologies. Generally, direct catalyst loading techniques, which integrate catalyst material directly onto the air electrode structure, provide superior cycling performance to indirect catalyst loading techniques, which distribute an ex-situ synthesized material onto the top layer of the air electrode. Hybrid catalyst loading techniques, which grow catalyst material directly onto nanostructured supports and then integrate them throughout the air electrode architecture, offer a compromise between direct and indirect methods. University of Alberta | Publication | 2024-05-22 | Matthew Labbe, Ivey, D. |
| Characterization of magnetic particle alignment in photosensitive polymer resin: A preliminary study for additive manufacturing processesMaterial jetting 3D printing is an additive manufacturing technique that allows producing complex parts without tooling and minimum material wastage. In this study, orientation control of randomly shaped, anisotropic hard magnetic ferrite particles is demonstrated for material jetting-based additive manufacturing processes using a developed particle alignment configuration. Strontium ferrite and PR-48 photosensitive resin were used as the base materials. An automated experimental setup with two neodymium permanent cube magnets capable of generating a dipolar magnetic field was built to align magnetic particles in the resin. Particle alignment was characterized for directionality using images obtained through real time optical microscopy. The orientation of magnetic particles was observed to be dependent on the distance of separation between the cube magnets and the magnetization time. X-ray diffraction was used to indicate the c-axis alignment of the hexagonal strontium ferrite particles in the cured specimens. The influence of process parameters on particle orientation was evaluated, employing a full factorial experiment analysis. This fundamental research serves as a basis for constructing and optimizing the magnetic particle alignment setup for additive manufacturing processes. University of Alberta | Publication | 2018-05-30 | Balakrishnan Nagarajan, Alejandro Federico Eufracio Aguilera, "Michael Wiechmann", Ahmed Jawad Qureshi, Mertiny, P. |
| Colorimetric Voltmeter Using Colloidal Fe3O4@SiO2 Nanoparticles as an Overpotential Alarm System for Zinc-air Batteries University of Alberta | Publication | 2019-10-20 | "Lelin Zheng", Thuy (Wendy) Nguyen Thanh Tran, "Dinara Zhalmuratova", Ivey, D., Chung, H. |
| Composition effects of electrodeposited Co-Fe as electrocatalysts for the oxygen evolution reactionCobalt and Fe were co-electrodeposited as single crystal, faceted particles onto carbon paper to produce Co/Fe-oxyhydroxide oxygen evolution reaction (OER) catalysts with various Co/Fe ratios. Electron microscopy and Auger electron spectroscopy were used to investigate the morphology and composition of the electrodeposits. Iron content in the deposits increased with increasing Fe concentration in the electrolyte and Fe segregated to the particle surfaces. Electrochemical tests demonstrated that the deposit Co/Fe ratio influences OER activity by altering the electrochemically active surface area (ECSA) and charge transfer resistance. The OER activity increased with increasing Fe content up to ∼65 at% Fe, with a minimum overpotential of 0.33 V at 10 mA cm−2 in 1 M KOH. The fabricated OER catalysts were assembled into a Zn-air battery for discharge-charge cycling tests and showed lower charge potentials compared with bare carbon paper. University of Alberta | Publication | 2017-12-09 | Ming Xiong, Ivey, D. |
| Compositional Effects of Gel Polymer Electrolyte and Battery Design for Zinc\textendash Air BatteriesPoly(acrylic acid) (PAA) is a promising polymer host to support alkaline electrolytes in Zn-air batteries. Herein, precursors containing different concentrations of monomers, crosslinkers and additives such as zinc oxide in alkaline solution are polymerized to fabricate gel polymer electrolytes (GPEs) via one-pot synthesis. The compositional effects of the GPEs on battery performance are evaluated and a more efficient cell design is demonstrated. With a vertical double air electrode configuration, ZABs using PAA-based electrolytes show unprecedented performance including high specific energy (913 Wh kgZn−1), excellent cycling stability (at least 160 cycles at 2×10 mA cm–2) and high power density output (2×135 mW cm−2). The study represents a viable option to replace aqueous electrolytes for high performing ZABs. University of Alberta | Publication | 2020-05-01 | Thuy (Wendy) Nguyen Thanh Tran, Drew Aasen, Dinara Zhalmuratova, Matthew Labbe, Chung, H., Ivey, D. |
| Current Distribution Investigation and Structure Optimization of Zn-air Batteries3-D Modeling of a Zn-air battery was performed, using COMSOL Multiphysics software, to simulate its discharge and charge processes. The modeling was validated by comparing simulated electrochemical performance with experimental test results. The model was then used to investigate the current distribution across Zn electrode surface and to help explain its thickness change after cycling tests. The structure of the Zn-air battery was optimized to increase spatial utility and efficiency. Finally, a flowing electrolyte was simulated to facilitate uniform Zn electrodeposition. University of Alberta | Publication | 2018-08-07 | Ming Xiong, "Mehdi Alipour", Ivey, D. |
| Design and multi-objective optimization of fiber-reinforced polymer composite flywheel rotorsA multi-objective optimization strategy to find optimal designs of composite multi-rim flywheel rotors is presented. Flywheel energy storage systems have been expanding into applications such as rail and automotive transportation, where the construction volume is limited. Common flywheel rotor optimization approaches for these applications are single-objective, aiming to increase the stored energy or stored energy density. The proposed multi-objective optimization offers more information for decision-makers optimizing three objectives separately: stored energy, cost and productivity. A novel approach to model the manufacturing of multi-rim composite rotors facilitates the consideration of manufacturing cost and time within the optimization. An analytical stress calculation for multi-rim rotors is used, which also takes interference fits and residual stresses into account. Constrained by a failure prediction based on the Maximum Strength, Maximum Strain and Tsai-Wu criterion, the discrete and nonlinear optimization was solved. A hybrid optimization strategy is presented that combines a genetic algorithm with a local improvement executed by a sequential quadratic program. The problem was solved for two rotor geometries used for light rail transit applications showing similar design results as in industry. University of Alberta | Publication | 2018-07-30 | Marvin Mittelstedt, Mertiny, P. |
| Development and Characterization of Field Structured Magnetic Composites University of Alberta | Publication | 2021-08-01 | Balakrishnan Nagarajan, Yingnan Wang, Maryam Taheri, Simon Trudel, Steven Bryant, Qureshi, A., Mertiny, P. |
| Development and Characterization of Stable Polymer Formulations for Manufacturing Magnetic Composites University of Alberta | Publication | 2020-01-01 | Balakrishnan Nagarajan, Milad Kamkar, Martin AW Schoen, Uttandaraman Sundararaj, Simon Trudel, Qureshi, A., Mertiny, P. |
| Dimple Grinding Coupled with Optical Microscopy for Porosity Analysis of Metallic CoatingsDimple grinding is one of the steps used in a common method of preparing samples for transmission electron microscopy (TEM); the TEM sample preparation process also involves ion beam sputtering after the dimpling stage. During dimpling, a spherical depression is machined into the sample, leaving a thicker rim to support and facilitate sample handling. In this paper, an alternative application for dimple grinding is developed; dimple grinding combined with optical microscopy is utilized to quantify internal porosity present within coatings. This technique essentially permits three dimensional porosity quantification across the coating thickness using a simple polishing method which provides analysis of areas larger than those observed during standard cross sectional microscopy. The application of this technique to nine electroless nickel-phosphorus (Ni-P) coatings deposited on Mg substrates is demonstrated. University of Alberta | Publication | 2024-03-01 | Hang Hu, Anqiang He, Drew Aasen, "Shantanu Shukla", Ivey, D. |
| Dip-Coating Synthesis of rGO/α-Ni(OH)2@Nickel Foam with Layer-by-Layer Structure for High Performance Binder-Free SupercapacitorsThe conventional fabrication of composite electrodes often requires extraordinarily complex electrode preparation steps. We provide here a separate dip-coating method for ultrasmall α-Ni(OH)2 nanoparticles grown between reduced graphene oxide (rGO) sheets on nickel foam, forming a direct binder-free elec- trode of 3D rGO/α-Ni(OH)2@nickel foam (GNH@NF-n, layer number n= 5, 8, 10, 15, 20) with a layer-by- layer structure. At a charge and discharge current density of 1 A/g, the specific capacitance of GNH@NF-5 reaches 2118 F/g (capacity: 323.5 mAh/g). When the current density is changed from 1 to 10 A/g, the specific capacitance retains 74.8% of the maximum value (capacity retains 88.4%). Changes in structure and electrochemical performance are analyzed as the number of layers increases, i.e., as the mass load- ing increases. When the mass loading increases by a factor of 5.2 from 1.4 to 7.3 mg/cm2, the GNH@NF-n electrode maintains a very high specific capacitance, with a value as high as 89% of the capacitance (or capacity) for the lowest mass loading. Dipping separately in nickel-based and rGO solutions (separate dip-coating method) is more effective in achieving the layer-by-layer structure and high electrochemi- cal performance than dipping in a mixed solution (mixed dip-coating method). Furthermore, asymmetric GNH@NF-5//rGO supercapacitors are assembled and exhibit a high specific energy of 109.9 Wh/kg at a specific power of 1.3 kW/kg and a high cyclic stability with capacitance retention of 86.1% after 10,000 charge and discharge cycles. University of Alberta | Publication | 2020-12-01 | Michael Clark, "Liuqin Lai", "Siyu Su", "Rong Li", Ivey, D., "Xiaohong Zhu" |
| Effects of Crosslinker Concentration in Poly(Acrylic Acid)–KOH Gel Electrolyte on Performance of Zinc–Air BatteriesZinc–air batteries (ZABs) using gel polymer electrolytes suffer from low energy efficiency and poor cyclability. This issue is not only associated with the air electrode, as early failure of the battery is often due to the Zn electrode. Here, the cycle life of ZABs using alkaline poly(acrylic acid) (PAA–KOH) as the electrolyte is shown to vary by changing its crosslinking density. For ZABs using hydrogel electrolytes, understanding the failure mechanism and optimization of the hydrogel composition are key to achieving better utilization of the Zn electrode and battery rechargeability. In addition, the effects of crosslinker concentration on rheological properties, sol–gel fraction, ionic conductivity and water retention ability of the hydrogel are discussed. PAA–KOH gels with lower crosslinking concentrations are weaker, but they have higher conductivity and better water retention, whereas gels with higher crosslinking concentrations affect the diffusion of zincate ions and facilitate passivation of the Zn electrode, resulting in early failure of the battery. University of Alberta | Publication | 2020-04-01 | Thuy (Wendy) Nguyen Thanh Tran, Michael Clark, Chung, H., Ivey, D. |
| Effects of Viscoelasticity on the Stress Evolution over the Lifetime of Filament-Wound Composite Flywheel Rotors for Energy StorageAPA Citation: Skinner, M., & Mertiny, P. (2021). Effects of Viscoelasticity on the Stress Evolution over the Lifetime of Filament-Wound Composite Flywheel Rotors for Energy Storage. Applied Sciences, 11(20), 9544. University of Alberta | Publication | 2021-10-01 | Miles Skinner, Mertiny, P. |
| Efficient Low Temperature Performance of All Solid-State Zinc-air Batteries with MnCo2O4/Carbon Fiber Bifunctional Electrocatalyst and Poly(acrylic Acid) (PAA) Polymer ElectrolyteSpinel type MnCo2O4 coated on asphaltene based carbon fibers (MnCo2O4/CF) was used as the electrode material/electrocatalyst for air electrodes for zinc‐air batteries (ZABs). The batteries were assembled using an alkaline poly(acrylic acid) hydrogel electrolyte. The low temperature battery performance of the prepared ZAB cells was studied in terms of charge/discharge voltage and efficiency at different current densities, cycle life, power density, and cell voltage at temperatures between −45 °C and 21 °C. At all temperatures, the ZABs successfully completed 200 cycles of charge/discharge (100 h) at 2 mA cm−2 which is double the current density reported in the recent literature. The maximum power densities at 0 and −45 °C were 75 and 12 mW cm−2, respectively. The good performance is attributed to the porous design of the air electrode and the use of an efficient electrocatalyst and an optimized gel polymer electrolyte. University of Alberta | Publication | 2023-02-02 | "Zahra Abedi", Jiayao Cui, "Weixing Chen", Ivey, D. |
| Electrodeposited and Oxidized Mn/Co-Fe As Bi-Functional Electrocatalysts for Rechargeable Zinc-Air BatteriesIn this study, MnOX and CoFe were sequentially electrodeposited onto a gas diffusion layer (GDL) as bifunctional electrocatalysts for rechargeable zinc-air batteries. The fabricated material was then assembled into a zinc-air battery as the air electrode component to run battery cycling tests. The sequentially deposited MnOX-CoFe catalysts showed activities for both ORR and OER, better than either MnOX or CoFe alone. The zinc-air battery using MnOX-CoFe catalysts exhibited good discharge-recharge performance and an efficiency comparable to Pt/C catalysts. In addition, the electrodeposited MnOX-CoFe layer showed strong adhesion to GDL and was stable throughout battery cycling. University of Alberta | Publication | 2017-01-05 | Ming Xiong, Ivey, D. |
| Electrodeposited Co-Fe as an Oxygen Evolution Catalyst for Rechargeable Zinc-air BatteriesCobalt-iron (Co-Fe) nanocubes were directly electrodeposited onto carbon paper and utilized as efficient oxygen evolution reaction catalysts for rechargeable zinc-air batteries. The morphology and mass loading were directly controlled by adjusting deposition time and the deposits evolved from single crystal nanocubes into a continuous film. Co-Fe catalysts exhibited low overpotential, small Tafel slopes and high durability during testing. A zinc-air battery using Co-Fe showed the same cycling efficiency as one using commercial Pt/Ru catalysts. University of Alberta | Publication | 2017-02-01 | Ming Xiong, Ivey, D. |
| Electrodeposited Manganese Oxide on Carbon Paper for Zinc-Ion Battery CathodesNano-crystalline, flake-like Mn oxide was electrodeposited onto carbon paper (CP) using a pulsed electrodeposition technique. The electrodeposited Mn oxide was identified as Mn3O4 through a combination of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The Mn3O4 on CP was used as a cathode for Zn-ion batteries (ZIBs) and showed excellent cyclability at a current density of 1Ag University of Alberta | Publication | 2020-03-30 | "Arjun Dhiman", Ivey, D. |
| Ethylene Glycol as an Antifreeze Additive and Corrosion Inhibitor for Aqueous Zinc-Ion BatteriesAqueous zinc-ion batteries are promising candidates for port- able and large-scale applications because of their intrinsically high safety, low cost and high theoretical energy density. However, existing aqueous zinc-ion batteries usually suffer from zinc corrosion and poor performance at subzero temperatures. Herein, to address these problems, the electrolyte in aqueous zinc-ion batteries (1 M ZnSO4) is optimized by adding suitable amounts of ethylene glycol. The addition of ethylene glycol improves the antifreezing ability of the aqueous electrolyte and increases the conductivity of electrolyte at low temperatures. Ethylene glycol serves two purposes, as an antifreeze additive to significantly enhance the capacity of batteries at low temperatures and as a corrosion inhibitor to suppress zinc corrosion and byproduct precipitation. This work offers a facile strategy to realize aqueous zinc-ion batteries with good performance at low temperatures. University of Alberta | Publication | 2022-05-01 | Thuy (Wendy) Nguyen Thanh Tran, Maosen Zhao, "Shujiang Geng", Ivey, D. |
| Experimental Characterization of Low-Speed Passive Discharge Losses of a Flywheel Energy Storage System University of Alberta | Publication | 2021-01-01 | Miles Skinner, Mertiny, P. |
| Experimental Concerns of Current Collector Interference and Electrolyte Creep During Zinc-Air Battery TestingEvaluating the electrochemical performance of catalysts towards the oxygen reduction and evolution reactions in zinc-air batteries is a routine process often conducted using a two-electrode cell. At the air electrode, a current collector is necessary if a carbon paper-based gas diffusion layer (GDL) is employed. The catalytic properties of the current collector may interfere with the studied catalyst on the GDL if flaws in cell design allow electrolyte contact to be made with the current collector. At the zinc electrode, highly alkaline electrolytes (e.g., KOH), with high surface tension, can easily climb up the electrode and accumulate at the interface between the cell and the surrounding atmosphere. An oxygen concentration cell is then enabled by the deposited electrolyte and the zinc electrode is rapidly corroded until failure, prematurely ending a long-term cycling test. University of Alberta | Publication | 2023-05-06 | Matthew Labbe, Ivey, D. |
| Growth of Multiple Island Layers during Iron Oxide Atomic Layer Deposition: An Electron Microscopy and Spectroscopic Ellipsometry InvestigationAtomic layer deposition (ALD) of FeOx thin films, prepared using the air stable and low cost precursor of ethylferrocene, was characterized through electron microscopy and spectroscopic ellipsometry (SE) techniques. To model the growth behavior of the layer on carbon-based air electrodes in metal–air batteries, carbon substrates were employed for electron microscopy. Electron imaging revealed an island morphology for the FeOx deposits, which eventually coalesced into a continuous film with pinholes. Further growth resulted in another layer of islands forming on top of the continuous film, in a process that was repeated throughout deposition. In situ SE exhibited both substrate-enhanced and substrate-inhibited characteristics; the former was due to a MnOx seed layer deposited prior to FeOx ALD, while the latter was a consequence of the island growth mode. After an extended number of ALD cycles, the process entered a linear growth regime, which is typically associated with layer-by-layer growth. The application of an effective medium approximation model to the SE data revealed the nucleation of six different layers of FeOx islands through 650 ALD cycles. This novel work showcases the need for multiple characterization techniques to confirm the growth mode displayed by an ALD process. University of Alberta | Publication | 2022-11-10 | Matthew Labbe, Ken Cadien, Ivey, D. |
| High Performance Oxygen Reduction/Evolution Electrodes for Zinc-Air Batteries Prepared by Atomic Layer Deposition of MnOxOxygen reduction electrodes for zinc–air batteries (ZAB) have been prepared by depositing conformal films of MnOx directly onto high surface area gas diffusion layers (GDL) via atomic layer deposition (ALD). MnOx films were prepared by means of two deposition conditions: one using a forming gas (95% N2, 5% H2) plasma (FG-MnOx) and one using an O2 plasma (O2-MnOx). A composite electrode of FG-MnOx + CoOx was also examined. The conformal nature of ALD films allowed for MnOx to be deposited within the porosity of the GDL, as confirmed by X-ray microanalysis. Full cell ZAB tests showed excellent performance for MnOx-coated electrodes, outperforming Pt/Ru–C at current densities larger than 100 mA cm–2. Annealed FG-MnOx and O2-MnOx electrodes had maximum power densities of 170 and 184 mW cm–2, respectively. With the catalyst distributed within the structure of the GDL, performance limitations associated with electrolyte flooding and air diffusion are reduced, improving discharge potential and cycling behavior. FG-MnOx + CoOx electrodes showed good cycling stability, both in a trielectrode configuration and bifunctionally. When cycled at 20 mA cm–2 for 100 h (200 cycles), FG-MnOx + CoOx had initial and final discharge potentials of 1.18 and 1.15 V, respectively. University of Alberta | Publication | 2020-04-01 | Michael Clark, Ming Xiong, Ken Cadien, Ivey, D. |
| Hollow Mesoporous Carbon Nanospheres Decorated with Metal Oxide Nanoparticles as Efficient Earth-Abundant Zinc-Air Battery CatalystsHybrids comprising hollow mesoporous nitrogen doped carbon (HMC) nanospheres and metal oxide-nanoparticles were prepared via a hydrothermal synthesis. These materials exhibit excellent bifunctional catalytic activity in the oxygen reduction and evolution reactions (ORR and OER, respectively) that core to the efficient operation of Zn-air batteries. When incorporated into prototype devices, Co3O4 and MnCo2O4 nanoparticle decorated HMC exhibited discharge potentials of 1.26 and 1.28 V at 10 mA cm-2, respectively. ‘CoFeNiO’ decorated HMC exhibited a charging potential of 1.96 V at 10 mA cm-2. These metrics are much superior to benchmark Pt-Ru, which displayed discharge and charging potentials of 1.25 and 2.01 V, respectively, at the same current density. The battery equipped with Co3O4 decorated HMC demonstrated 63% initial efficiency before cycling. After cycling at 10 mA cm-2 for 200 hours, the battery efficiency was maintained at 56.5%, outperforming the battery with Pt-Ru (50.2% after 50 h). University of Alberta | Publication | 2021-01-07 | Yingjie He, Drew Aasen, Alexandra McDougall, Haoyang Yu, Matthew Labbe, Chuyi Ni, Sarah Milliken, Ivey, D., Jonathan GC Veinot |
| In-situ Transformation of Electrodeposited W-Co Oxide to ZnCo2O4 Nanoparticles as Effective Bifunctional Catalysts in ZABsW-Co was cathodically electrodeposited on gas diffusion layer (GDL) electrodes for application as a bifunctional catalyst for Zn air batteries. The electrodes were synthesized galvanostatically at various pH values (4.5 and 7.5) and deposition times (5, 15 and 25 min). Transmission electron microscopy (TEM) analysis showed that the deposits oxidized in contact with air, forming a conformal layer of W-Co oxide with a thickness of ~10 nm. During battery cycling, most of the W dissolved in the electrolyte. The remaining Co oxide agglomerated, forming nanoparticles less than 100 nm in size. Zinc (present in the electrolyte as ZnO) was incorporated into the Co oxide nanoparticles. As such, the conformal layer of W-Co oxide transformed into cubic spinel ZnCo2O4 nanoparticles which provided excellent bifunctional catalytic activity. The W in the original deposit acted as a conduit to facilitate formation of the ZnCo2O4 nanoparticles. The ZnCo2O4 catalyst demonstrated good performance in two-electrode and three-electrode full-cell Zn-air battery tests. In three-electrode tests at 10 mA cm-2, a round trip efficiency of 62% was achieved, exceeding the efficiency of Pt/Ru-C (61%). In two-electrode tests at 10 mA cm-2, an initial efficiency of 61% was obtained and the stability exceeded that of Pt/Ru-C. The final efficiencies were 59% for the three-electrode and 56% for the two-electrode configuration (after 100 cycles). A high maximum power density of 216 mW cm-2 was also achieved. University of Alberta | Publication | 2020-04-07 | "Josiel Costa", Michael Clark, Ambrosio F de Almeida Neto, Ivey, D. |
| Investigation of Transition Metal-Based (Mn, Co, Ni, Fe) Trimetallic Oxide Nanoparticles on N-doped Carbon Nanotubes as Bifunctional Catalysts for Zn-Air BatteriesVarious transition metal-based bimetallic and trimetallic oxides on N-CNTs were successfully synthesized in a one-pot process. Porous gas diffusion layers (GDLs) were simultaneously impregnated with the catalysts during synthesis, resulting in an efficient and scalable preparation technique for nano-composite air electrodes. NiMnOx/N-CNT, NiFeOx/N-CNT, and (Co,Fe)3O4/N-CNT catalysts were the highest performing bimetallic oxides based on battery rate test results. Therefore, Ni-Co-Fe, Ni-Mn-Fe, and Mn-Co-Fe systems were investigated as combined trimetallic oxide/N-CNT catalysts for Zn-air batteries. Trimetallic oxides on N-CNTs exhibited improved OER activity and comparable ORR activity relative to the bimetallic oxide catalysts in linear sweep voltammetry (LSV) tests. Discharge/charge efficiencies for tri-metallic oxides on N-CNTs calculated from battery rate test measurements at a current density of 20 mA cm−2 were 60.5%, 60.7%, and 60.0% for NCFO/N-CNT, NMFO/N-CNTs and MCFO/N-CNT, respectively. Bifunctional cycling of all trimetallic oxide/N-CNT electrodes at 10 mA cm−2 for 100 h showed excellent stability, particularly the NCFO/N-CNT catalyst. Additionally, the efficiencies for NCFO/N-CNT, NMFO/N-CNT and MCFO/N-CNT samples were 58.5%, 57.9% and 57.2%, respectively, after cycling, which compare favorably with that of Pt-Ru/C (55.3%). Trimetallic oxides on N-CNTs are, therefore, excellent candidates as high performing, non-precious metal catalysts for Zn-air batteries. University of Alberta | Publication | 2020-02-11 | Drew Aasen, Michael Clark, Ivey, D. |
| Low-Temperature Tolerant Poly(Acrylic Acid) (PAA) Gel Polymer Electrolytes for Rechargeable Zinc-Air BatteriesGel polymer electrolytes (GPEs) are emerging materials for Zn-air batteries (ZABs), since the GPE can act as a combined electrolyte and separator in the battery. GPE-KOH was fabricated through the polymerization of poly(acrylic) acid in the presence of KOH and ZnO. GPE-KOH-KI was fabricated following a similar procedure, followed by immersion in a solution containing KOH, KI and ZnO. The addition of KI to the electrolyte changed the conventional charging reaction to a reaction with a lower thermodynamic barrier, which improved the battery efficiency with a maximum increase of 36% relative to ZABs without KI. This work focused on extending the working temperature range of the ZAB to low temperatures (as low as -41℃) as well as exploring the reaction mechanism for ZABs using KI as an additive. It is proposed that the discharging reaction at the air electrode is a combination of the oxygen reduction reaction and iodate reduction reaction. University of Alberta | Publication | 2023-05-11 | Jiayao Cui, Matthew Labbe, Chung, H., Ivey, D. |
| Magnetic Filler Polymer Composites - Morphology Characterization and Experimental and Stochastic Finite Element Analyses of Mechanical Properties University of Alberta | Publication | 2023-06-01 | Yingnan Wang, Hamidreza Ahmadimoghaddamseighalani, Jorge Alberto Palacios Moreno, Mertiny, P. |
| Magnetically loaded polymer composites using stereolithography\textemdash Material processing and characterization University of Alberta | Publication | 2020-12-01 | Balakrishnan Nagarajan, Mertiny, P., Qureshi, A. |
| Mn3O4 Nanoparticle-Decorated Hollow Mesoporous Carbon Spheres as an Efficient Catalyst for Oxygen Reduction Reaction in Zn-air BatteriesHybrids of Mn3O4 nanoparticles and hollow carbon spheres prepared from templated pyrolysis of polydopamine were assembled via a straightforward sonication procedure. The resulting hybrids exhibit excellent catalytic activity toward the oxygen reduction reaction (ORR) in prototype Zn–air batteries. Impressively, these catalysts exhibit higher discharge potential and exceptional stability when compared to commercial Pt–Ru catalysts while simultaneously showing comparable onset potential and maximum current density. University of Alberta | Publication | 2020-06-19 | Yingjie He, Drew Aasen, Haoyang Yu, Matthew Labbe, Ivey, D., Jonathan GC Veinot |
| Multifunctional Hybrid Fiber Composites for Energy Transfer in Future Electric Vehicles University of Alberta | Publication | 2022-09-08 | Till Adam, Peter Wierach, Mertiny, P. |
| Rheology-Assisted Microstructure Control for Printing Magnetic Composites\textemdash Material and Process Development University of Alberta | Publication | 2020-09-01 | Balakrishnan Nagarajan, Martin AW Schoen, Simon Trudel, Qureshi, A., Mertiny, P. |
| Saturation Behaviour of Atomic Layer Deposition MnOx from Bis (Ethylcyclopentadienyl) Manganese and Water: Saturation Effect on Coverage of Porous Oxygen Reduction ElectrodesMnOx deposits on porous gas diffusion layer (GDL) substrates for application as catalysts for the oxygen
reduction reaction (ORR) in metal−air batteries have been prepared using atomic layer deposition (ALD). The saturation behavior of the bis(ethylcyclopentiadienyl) manganese ((EtCp)2Mn) and H2O ALD system has been investigated. The observed saturation behavior is in disagreement with previous reports in literature. (EtCp)2Mn + H2O depositions exhibited non-ALD behavior, as demonstrated by a high growth per cycle (GPC) at substrate temperatures (Tsub) = 40−50 °C and nonsaturating reactions at Tsub ≥ 60 °C. The introduction of a forming gas (FG) (95% N2 + 5% H2) plasma between the (EtCp)2Mn and H2O doses promoted precursor saturation with a constant GPC (1.15 Å/cy) in the Tsub range of 100−200 °C. The effect of saturation behavior on porosity coverage was investigated by coating porous carbon electrodes with ALD MnOx. Energy dispersive X-ray (EDX) spectroscopy, electrochemical surface area measurements, and oxygen reduction activity all indicate that the saturating behavior of the (EtCp)2Mn + FG + H2O deposition resulted in superior coverage compared with the (EtCp)2Mn + H2O depositions. University of Alberta | Publication | 2018-12-19 | Michael Clark, Ming Xiong, Ken Cadien, Ivey, D. |
| Synthesis of Bifunctional Catalysts for Metal-Air Batteries Through Direct Deposition MethodsRechargeable metal-air batteries, such as Li-air and Zn-air batteries, have gained renewed interest because of their high theoretical energy density, safety and low cost. The air electrode, with bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), plays the most important role in determining battery performance. Direct deposition of catalysts on the air electrode, using methods such as electrodeposition, electroless deposition, chemical vapor deposition (CVD) and physical vapor deposition (PVD), is shown to be a viable way to fabricate durable and active catalysts with high efficiency and low cost. This review examines recent research activities which apply direct deposi- tion methods to prepare bifunctional catalysts. The benefits and drawbacks of these methods are compared to provide guide- lines for their application. University of Alberta | Publication | 2018-09-06 | Ming Xiong, Ivey, D. |
| The Corrosion Behavior of Electroless Ni-P Coatings in Concentrated KOH ElectrolyteNi-P has been widely used as a protective coating for many substrates. The corrosion resistance of Ni-P in neutral solutions such as NaCl, or acidic electrolytes such as HCl and H2SO4, has been extensively studied. However, the corrosion behavior of Ni-P coatings in caustic media, such as KOH, has received much less attention. Typically, corrosion behavior is studied through the use of electrochemical methods with corrosion rates determined from corrosion currents and potentials measured from Tafel curves. In this work, the corrosion rates of Ni-P coatings, with P concentrations varying from 2 to 11 wt%, in highly alkaline KOH (11 M) are obtained directly through electron microscopy measurements of cross sections and subsequent correlation with electrochemical data. Phosphorus concentration affects the corrosion rate; corrosion rate increases with increasing P content, peaks out at about 6-8 wt% P, and then decreases with any further increase in P content. This behavior is correlated to internal stress levels developed in the coatings. University of Alberta | Publication | 2024-05-18 | Anqiang He, Hang Hu, Drew Aasen, Ivey, D. |
| Tri- and Tetra-Metallic Oxides Anchored to Heteroatom Doped Carbon Nanotubes as Bifunctional Electrocatalysts for Rechargeable Zinc-Air BatteriesElectrochemical catalysts for the air electrode of Zn-air rechargeable batteries were fabricated from nitrogen-doped carbon nanotubes (N-CNTs), combined with either tri-metallic (Ni–Mn–Co) or tetra-metallic (Zn–Ni–Mn–Co) oxides, through a simple impregnation method into carbon-based, gas diffusion layers (GDL). Metal oxide compositions were selected based on previous results, preliminary electrochemical testing, and statistical design of experiments. Microstructural characterization was done using electron microscopy and X-ray photoelectron spectroscopy. Samples were electrochemically tested and the best candidates were subjected to full cell testing and bifunctional cycling for 200 charge/discharge cycles at 10 mA cm−2. The overall bifunctional efficiency, after cycling, of the best NiMnCoOx/N-CNT and ZnNiMnCoOx/N-CNT catalysts was 53.3% and 56.4%, respectively; both outperformed Pt–Ru/C in both overall bifunctional efficiency (38%) and cycling stability. The maximum power density of one of the tetra-metallic oxides exceeded that of Pt–Ru/C (110 mW cm−2) at 134 mW cm−2. The addition of Zn with Ni–Mn–Co oxide particles showed improved cycling stability and overall bifunctional efficiency. University of Alberta | Publication | 2021-11-09 | Alexandra McDougall, "Zahra Abedi", Ivey, D. |
| Zinc-Air Batteries with Efficient and Stable MnCo2O4/Carbon Fiber Bifunctional Electrocatalyst and Poly(acrylic Acid) (PAA) Based Gel ElectrolyteEfficient and high-performance zinc–air batteries (ZABs) with gel polymer electrolytes (GPEs) were prepared. Cubic spinel-type MnCo2O4-coated carbon fibers (MnCo2O4/CF) were used to prepare air electrodes, and poly(acrylic acid) was used to prepare alkaline GPEs. Materials characterization, including electron microscopy and X-ray photoelectron spectroscopy, confirmed the formation of MnCo2O4 on the CFs. The optimum composition of the GPE was determined by rheological measurements and battery testing; using GPE with a crosslinker concentration of 30 mM led to the best performing battery. Full-cell battery tests and cycling tests showed that this ZAB cell had outstanding performance with an initial efficiency of 62.6% at 10 mA cm–2, which degraded by only 6.5% after 200 cycles (100 h). The power output of this cell was 240 mW cm–2, which is superior to the power outputs reported in the recent literature for ZABs. University of Alberta | Publication | 2022-11-04 | "Zahra Abedi", Jiayao Cui, "Weixing Chen", Ivey, D. |
| Zn-Based Oxides Anchored to Nitrogen-Doped Carbon Nanotubes as Efficient Bifunctional Catalysts for Zn-Air BatteriesZn-Co oxide (ZnCoOx), Zn-Mn oxide (ZnMnOx), Zn-Mn-Co oxide (ZMCO), and Zn-Co-Fe oxide (ZCFO) nanoparticles were successfully synthesized on nitrogen-doped carbon nanotubes in a one-pot process. Porous carbon paper was simultaneously impregnated with the catalysts during synthesis and used as air electrodes for Zn-air batteries. ZnMnOx/N-CNT catalysts had the best ORR performance in half-cell LSV experiments with a more positive onset potential than that of Pt-Ru/C (-0.067 V and -0.078 V vs Hg/HgO, respectively). ZCFO/N-CNT catalysts had the best activity towards OER among the Zn-based oxide catalysts in half-cell linear sweep voltammetry (LSV) testing with an onset potential of 0.63 V vs Hg/HgO. Round-trip efficiencies from battery rate tests at a current density of 20 mA cm-2 were 55.3%, 57.5%, 58.7%, and 58.3% for ZnCoOx/N-CNT, ZnMnOx/N-CNT, ZMCO/N-CNT, and ZCFO/N-CNT, respectively. Bifunctional cycling of the catalysts was done in a homemade Zn-air battery at a current density of 10 mA cm-2 for 200 cycles. The final round trip efficiencies for ZnCoOx/N-CNT, ZnMnOx/N-CNT, ZMCO/N-CNT, and ZCFO/N-CNT were 55.8%, 56.6%, 54.2%, and 55.0%, respectively. All catalysts except ZCFO/N-CNT compared favorably with Pt-Ru/C in terms of round-trip efficiency after cycling (55.3%). Incorporation of Zn into the metal oxide particles showed improved catalytic activity for ZnCoOx/N-CNT and ZnMnOx/N-CNT compared with MnOx/N-CNT and CoOx/N-CNT catalysts prepared via the same technique. University of Alberta | Publication | 2020-05-05 | Drew Aasen, "Yi Shen", Ivey, D. |
| ABAQUS Analysis of Polygonal Hub ExtensionThis visiting student research project involved the design and analysis of a hub concept for a 6.5 kWh flywheel energy storage system with target operating speed of 35000 revolutions per minute. | Activity | 2017-10-16 | Carmen Pomp |
