Collaborative Design of Multi-Molecules Boosts the Performance of the Full-Range Three-Dimensional Quasi-Solid Polymer Electrolyte for Lithium Metal Batteries.

Solid polymer electrolytes, known for their ease of processing and excellent interfacial contact, play a crucial role in developing high-energy-density lithium metal batteries. To address the limitations of single-function polymer electrolytes such as polyethylene oxide and polyacrylonitrile, it's imperative to develop polymer electrolytes with superior comprehensive performance by incorporating functional organic molecules. In this study, a quasi-solid polymer electrolyte named VAPE is prepared using a multivariate molecular synergistic strategy. This approach integrates vinyl acetate (VAC), acrylonitrile (AN), and trimethylolpropane ethoxylate triacylate (ETPTA) into a full-range, 3D cross-linked network via radical-initiated polymerization. The cross-linked structure and the synergistic effect of multiple functional units accelerate the lithium-ion transport kinetics of VAPE and induce the formation of dense and stable solid-electrolyte interphase and cathode-electrolyte interphase layers. As a result, the assembled Li/VAPE/Li symmetric cell exhibits stable cycling for over 800 h. Furthermore, the terpolymer electrolyte VAPE demonstrates an electrochemical window up to 5.30 V. Therefore, the LiNiMnCoO (NCM811)/VAPE/Li battery displays excellent cycling stability with 80% capacity retention after 350 cycles at 0.5C. Even at the ultra-high cut-off voltage of 4.7 V, the NCM811/VAPE/Li battery achieves a capacity retention rate of 84.8% after 100 cycles at 0.2C.