Triple-phase engineered cellulose-based electrolytes via polymerization-mixing-impregnation strategy for lithium metal batteries

Poly(ethylene oxide) (PEO) is widely employed as the matrix material for solid polymer electrolytes (SPEs) in lithium-metal batteries (LMBs). However, inherent drawbacks such as high crystallinity and excessive lithium-ion coordination effects severely hinder its practical applications. To address these limitations, this work develops an integrated polymerization-mixing-impregnation (PMI) strategy, fabricating a PACP-PEO@CF SPE through polymerizing of P(AN- co -PEGMA), mixing with PEO, and impregnating onto a cellulose framework (CF). Complementary density functional theory (DFT) calculations elucidate the critical role of PACP's functional groups in facilitating Li + transport. This approach simultaneously enhances Li + conductivity, dendrite suppression capability, and cycling stability in assembled PACP-PEO@CF-supported LMBs, effectively overcoming the intrinsic constraints of cellulose-based SPEs. It is impressive that the PACP-PEO@CF SPEs exhibits a high ionic conductivity of 1.95 × 10 −4  S cm −1 at 25 °C, a Li + transference number of 0.62, a wide electrochemical stability window of 5.6 V, and exceptional Li plating/stripping stability (>440 h at 0.1 mA cm −2 ). Furthermore, corresponding LMBs achieve stable cycling over 500 cycles at 0.5C and 45 °C. This study not only enhances lithium-ion conductivity through the molecular design of PACP polymer chains and their mixing with PEO, as supported by theoretical simulations, but also leverages the scaffold effect of CF to improve mechanical support and interfacial stability. This viable strategy further advances the application of biomass-derived materials in advanced energy storage technologies.