Interfacial ionic conductivity and cyclic performance of lithium metal battery using in-situ polymerized poly(vinylene carbonate)-Li6.4Ga0.2La3Zr1.4O12 solid electrolytes

Abstract

Solid-state batteries have become an effective way to improve battery safety and achieve high energy density. However, the high interfacial impedance and low ionic conductivity of solid-state electrolytes remain limiting factors in the development of all-solid-state batteries. In this study, a Poly (vinylene carbonate) (PVC)- Li_6.4Ga_0.2La₃Zr₂O₁₂(LLZO) composite electrolyte prepared by in-situ curing technology forms a tight interfacial contact through in-situ curing, reducing the interfacial resistance and enhancing the stability of solid-state batteries. The high LLZO content integrated with the PVC polymer creates a unified structure that facilitates lithium-ion migration and improves stability electrolyte stability.The composite electrolyte achieves an excellent ionic conductivity of 5.1 × 10⁻⁴ S/cm at room temperature, an electrochemical window greater than 4.7 V (vs Li⁺/Li), and a lithium-ion migration number of 0.616. Additionally, the PVC-LLZO composite solid electrolyte demonstrates significantly enhanced stability during lithium deposition and stripping. The solid-state LiFePO₄| PVC-20 wt% LLZO |Li batter shows outstanding cycling stability at 0.2C, with an initial discharge specific capacity of 137 mAh g⁻¹ and a capacity retention of 99.8 % after 160 cycles.