| Sintering of W-substituted Na3SbS4 Electrolytes: Effect of Phase Composition, Voids, and Interface ContactTungsten-substituted Na3SbS4 shows enhanced ionic conductivity but the role of sintering treatments is not well understood. The effects of sintering on Na3–xSb1–xWxS4 were examined and found to slightly increase the solubility of W, reduce voids, and possibly increase contact area. Changes in phase composition and morphology play a key role in the performance of Na3–xSb1–xWxS4 electrolytes. University of Alberta | Publication | 2025-07-25 | Fuwei Wen, Xiang You, Xie, G., Mar, A., Sang, L. |
| Pushing the Limit of in-Situ Characterization in All-Solid-State Battery: Full Decomposition Mechanism of Na3SbS4 Electrolyte Under Precise Potential ControlWith its higher ionic conductivity and lower flammability, the all-solid-state battery (ASSB) is expected to become a promising alternative to current liquid-state batteries. As the key difference between those two types of cells, electrolyte presenting in solid phase introduces additional complexity such as the formation of a solid electrolyte interface (SEI) in an imperfect solid-solid interface. Compared with liquid batteries, this imperfect contact in ASSBs leads to a heterogeneous decomposition and a more complicated SEI formation mechanism. Moreover, the opaque nature in ASSBs also challenges the conventional optical spectroscopy method used to characterize their decay mechanism. Therefore, a post-cycle ex-situ characterization remains the most widely applied approach to study the decomposition in ASSB [1]. However, as the key trigger of SEI formation, the stepwise involvement of anodic or cathodic potentials in electrolyte decomposition is not well understood. Despite significant challenge in characterization method design, in-situ study remains a pivotal approach to a complete kinetic and thermodynamic story of decomposition mechanism in the ASSB.
In our previous work, in-situ Raman characterization was performed at the anode/electrolyte interface in sodium ASSB [2]. This non-destructive method with an easy set-up has shown its potential in the study of SEI formation mechanisms, but the precise control of the potential experienced by electrolyte failed due to the heterogeneity of the electrode/electrolyte contact. In this study, we optimize our previous old Raman experiment set-up and achieve precise characterization of the electrochemical window (EW) of Na3SbS4 (NAS) and its derivative, carboxymethyl cellulose coated NAS (NAS-CMC). Precise potential control was accomplished by a hybridizing electrolyte design. Our results have suggested that NAS exhibit an EW from + 1.34 V to + 2.10 V vs Na/Na+. NAS was reduced to Na-Sb binary below 1.34 V, and this process was partially reversible. Additionally, another decomposition mechanism causes NAS to irreversibly decompose into Na3SbS3, but this mechanism doesn’t have a clear critical potential. At potentials more positive than 2.10 V, NAS was oxidized to form an Sb-S complex. In contrast, NAS-CMC shows suppressed decomposition to Na-Sb binary, and the critical potential of this decomposition is lowered to 1.0 V~ 0.4 V. Up to now, many following-up experiments are being performed and more details will be shared during the meeting.
References:
1. Jia, H. H.; Peng, L. F.; Yu, C.; Dong, L.; Cheng, S. J.; Xie, J. Mater.Chem. A 2021, 9 (9), 5134−5148.
2. Xie, G.; Tang, M.; Xu, S. H.; Brown, A.; Sang, L. ACS Appl. Mater. Interfaces 2022, 14, 43, 48705–48714 University of Alberta | Activity | 2025-05-18 | Xie, G., Sang, L. |
| Cellulose-Encapsulated Composite Electrolyte Design: Toward Chemically and Mechanically Enhanced Solid-Sodium Batteries University of Alberta | Publication | 2024-06-12 | "Shu Dong", Xie, G., "Shihong Xu", XueHai Tan, Madhu Sudan Chaudhary, "Yue Zhang", Runqi Wu, Fuwei Wen, "Cagri Ayranci", Michaelis, V., "Amanda Quirk", Scott M Rosendahl, "Jian Liu", Michael D Fleischauer, Sang, L. |
| Navigating Solvent Chemistry and Microstructures: Toward Mechanically Enhanced Ceramic-Rich Composite Electrolytes University of Alberta | Publication | 2024-10-04 | Sang, L., "Mauricio Ponga", "Michael Fleischauer", Runqi Wu |
