In Situ Synthesis of a Li6.4La3Zr1.4Ta0.6O12/Poly(vinylene carbonate) Hybrid Solid-State Electrolyte with Enhanced Ionic Conductivity and Stability

Solid-state electrolytes represent a new trend for designing safe lithium batteries. However, the application is still plagued by the relatively low ionic conductivity. Herein, a Li6.4La3Zr1.4Ta0.6O12/poly(vinylene carbonate) (LLZTO/PVCA) hybrid is fabricated by an in situ polymerization strategy. Benefiting from the integrated interfaces and extended lithium-ion transfer channels, a superior ionic conductivity of up to 7.8 × 10–5 S cm–1 is achieved at room temperature. Meanwhile, it presents a wide electrochemical window over 4.5 V (vs Li+/Li), and the lithium-ion transference number is 0.556. Additionally, the LLZTO/PVCA hybrid also exhibits excellent flexibility for buffering volume fluctuation during cycling. The solid-state LFP|LLZTO/PVCA|Li battery exhibits an initial capacity of 157 mA h g–1, 83% retention over 120 cycles, and an average Coulombic efficiency over 99% at 0.1 C, demonstrating good application potential.