A high-performance solid electrolyte assisted with hybrid biomaterials for lithium metal batteries

The demand for high safety lithium batteries has led to the rapid development of solid electrolytes. However, some inherent limitations of solid polymer electrolytes (SPEs) impede them achieving commercial value. In this work, a novel polyethylene oxide (PEO)-based solid electrolyte is reported. For the first time, biomaterial-based chitosan-silica (CS) hybrid particles serve as fillers, which can interact with polymer matrix to significantly improve the electrochemical performance. The optimized polymer electrolyte exhibits a maximum ion conductivity of 1.91 × 10^-4 S·cm^-1 at 30 °C when the mass ratio of PEO and CS is 4:1 (PCS4). All-solid-state LiFePO₄|PCS4|Li cells deliver a high coulombic efficiency and stable cycling performance, remaining an excellent capacity of more than 96.2 % after 150 cycles. Furthermore, the wide electrochemical window (5.4 V) and steady interfacial stability provide the possibility for high-voltage batteries applications. NCM811|| Li cells are assembled and display reliable charge and discharge cycle properties.