A Chitosan/Poly(ethylene oxide)‐Based Hybrid Polymer Composite Electrolyte Suitable for Solid‐State Lithium Metal Batteries

Abstract Solid‐state electrolytes have good mechanical and thermal stability to meet the safety and performance of advanced lithium‐based rechargeable battery technologies. However, the drawbacks such as high interfacial impedance and low ionic conductivity of the solid‐state polymer electrolytes at room temperature are the current demanding challenges that need to be addressed. Here, we report hybrid polymer composite electrolyte that is composed of a chitosan composite polymer electrolyte soaked with a slightly liquid electrolyte. The hybrid polymer composite electrolyte has a high ionic conductivity about 6.8×10 −4 S cm −1 with a low interfacial impedance at room temperature and outstanding flexibility. The lithium‐metal/LiFePO 4 solid‐state cell using this hybrid polymer composite electrolyte can be operated at room temperature maintaining a high cathode capacity of 120 mA h g −1 for 130 cycles. This chitosan/poly(ethylene oxide)‐based hybrid polymer composite electrolyte system provides a promising direction for the creation of novel solid‐electrolyte, which meets both high ionic conductivity and low interfacial impedance requirements for practical solid‐polymer batteries.