A Novel Cellulose-Supported Polymer Electrolyte with High Ionic Conductivity for Lithium Metal Batteries

The traditional liquid electrolytes pose safety hazards primarily attributed to the flammability of organic solvent, whereas solid-state electrolytes can significantly enhance the safety of lithium-ion batteries. Polymer solid electrolytes are being considered as an effective solution due to their excellent flexibility and low cost, but they suffer low ionic conductivity or high interface impedance. Here, the ketone-containing allyl acetoacetate monomers were polymerized within the cellulose membrane via UV photopolymerization to prepare a cellulose-supported poly-allyl acetoacetate polymer electrolyte. The PAAA electrolyte shows the ion conductivity of 1.14 × 10⁻⁴ S cm⁻¹ and the electrochemical stability window of 4.5 V. The Li symmetric battery can stably cycle for 1500 h at 0.1 mA cm⁻². The LiFeO₄‖Li cell achieves a discharge specific capacity of 160 mAh g⁻¹ and demonstrates excellent cycling stability. Matching with Ni-rich cathodes also delivers decent performance. The designed polymer electrolyte with high ionic conductivity offers new ideas and directions for the development of future energy storage technology.