Mechano-Electrochemical Synergy in Cellulose@MOF Scaffold-Based Asymmetric Electrolyte for Stable Solid-State Lithium Metal Batteries.

The application of polymer electrolytes is expected to revitalize solid-state lithium metal batteries (SSLMBs) with high energy density and enhanced safety. However, practical deployment faces challenges from inadequate mechanical properties of electrolyte and unstable interfaces in high-voltage SSLMBs. Herein, we design an asymmetric composite solid-state electrolyte (ACSE) composed of a cellulose framework in situ self-assembled with zeolitic imidazolate framework nanosheets (CP@MOF) embedded in a polymer matrix. The CP@MOF network provides the electrolyte with an elastic modulus of 1.19 GPa, effectively resisting Li dendrite penetration. Furthermore, theoretical calculations guided the compositional design of ACSE to address asynchronous interfacial requirements at cathode/electrolyte and anode/electrolyte interfaces, facilitating stable interphase formation and thus ensuring prolonged cycling of SSLMBs. Consequently, Li symmetric cells achieve extended cycling stability (> 5000 h) with minimal polarization. The NCM811|Li full cell maintains 84.9% capacity retention after 350 cycles. Notably, assembled NCM811 pouch cells deliver practical energy densities of 337.9 Wh kg-1 and 711.7 Wh L-1, demonstrating exceptional application potential. This work provides novel insights into the application of ACSEs for high-energy-density SSLMBs.