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Insight into Prolonged Cycling Life of 4 V All-Solid-State Polymer Batteries by a High-Voltage Stable Binder |
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| Authors: | Jianneng Liang Dachang Chen Keegan Adair Qian Sun Nathaniel Graham Holmes Yang Zhao Yipeng Sun Jing Luo Ruying Li Li Zhang Shangqian Zhao Shigang Lu Huan Huang Xiaoxing Zhang Chandra Veer Singh Xueliang Sun |
| Institution: | 1. Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON, N6A 5B9 Canada;2. Department of Materials Science and Engineering, University of Toronto, Toronto, ON, M5S 3E4 Canada
Department School of Electrical Engineering and Automation, Wuhan University, Wuhan, 430072 China China Automotive Battery Research Institute Co, Ltd, Beijing, 101407 China;3. China Automotive Battery Research Institute Co, Ltd, Beijing, 101407 China;4. Glabat Solid-State Battery Inc, 700 Collip Circle, Suite 211, London, ON, N6G 4 × 8 Canada;5. Department School of Electrical Engineering and Automation, Wuhan University, Wuhan, 430072 China Department School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan, 430068 China;6. Department of Materials Science and Engineering, University of Toronto, Toronto, ON, M5S 3E4 Canada |
| Abstract: | Polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) are incompatible with the 4 V class cathodes such as LiCoO2 due to the limited electrochemical oxidation window of PEO. Herein, a number of binders including commonly used binders PEO, polyvinylidene fluoride (PVDF), and carboxyl-rich polymer (CRP) binders such as sodium alginate (Na-alginate) and sodium carboxymethyl cellulose, are studied for application in the 4 V class all-solid-state polymer batteries (ASSPBs). The results show ASSPBs with CRP binders exhibit superior cycling performance up to 1000 cycles (60% capacity retention, almost 10 times higher than those with PEO and PVDF binders). Synchrotron-based X-ray absorption spectroscopy (XAS), morphology studies and density functional theory studies indicate that, with their carboxyl groups, CRPs can strongly bind the electrode materials together, and work as coating materials to protect the cathode/SPE interface. Cyclic voltammetry studies indicate that CRP binders are more stable at high voltage compared to PEO and PVDF. The stability under high voltage and the coating property of CRP binders contribute to stable cathode/SPE interfaces as disclosed by the X-ray photoelectron spectroscopy and Co L-edge XAS results, enabling long cycling life, high performance 4 V class ASSPBs. |
| Keywords: | binders high voltage batteries PEO polymer electrolytes solid polymer batteries solid-state batteries |