Multilayer structure solid-state electrolyte composite membranes for long-life quasi-solid-state battery

To reduce the impedance of the interface between solid electrolytes and electrodes and improve the in-terfacial stability, the liquid electrolyte (LE) is added between solid-state electrolytes and electrodes. We design LE containing different lithium salts, additives and a solid-state electrolyte membrane containing polyvinylidene fluoride (PVDF), Li1.3Al0.3Ti1.7(PO4)3 (LATP) and polypropylene membrane (PP) (LATP mem-brane), and systematically investigate the interfacial wettability, stability and safety through contact angle analysis, interfacial impedance measurements, and linear scanning voltammetry. The results show that the LE containing 1 M lithium hexafluorophosphate (LiPF6) salt, 1.3-propane sultone (1.3-PS) additive, adipo-nitrile, fluoroethylene carbonate (FEC), and that containing 0.575 M lithium bis(trifluoromethane sulfoni-mide) (LiTFSI)/0.575 M LiPF6 salt, trimethyl phosphate, FEC, and PS exhibit superior performance. The interfacial impedance of the Li|LE-LATP membrane-LE|Li coin cell is only-50 & omega;. The LiNi0.6Co0.2Mn0.2O2 (NCM622)|LE-LATP membrane-LE|Si/C coin cell exhibits an initial specific discharge capacity of-163 mAh g-1 at 0.5 C and 25 & DEG;C, and the capacity retention rate is-87% after 100 cycles. Furthermore, the 5 Ah NCM622|LE-LATP membrane-LE|Si/C pouch battery exhibits a capacity retention rate of > 90% after 400 cycles at 25 & DEG;C and 1 C.& COPY; 2023 Elsevier B.V. All rights reserved.