Ferroelectric Ceramic Materials Enable High-Performance Organic-Inorganic Composite Electrolytes in Solid-State Lithium Metal Batteries

Abstract Compared to commercial lithium-ion batteries, all-solid-state batteries can greatly increase the energy density, safety, and cycle life of batteries. The development of solid-state electrolyte with high lithium-ion conductivity and wide electrochemical window is the key for all-solid-state batteries. In this work, we report on the achievement of high ionic conductivity in the PAN/LiClO₄/BaTiO₃ composite solid electrolyte (CSE) prepared by solution casting method. Our experimental results show that the PAN-based composite polymer electrolyte with 5 wt% BaTiO₃ possesses a high room-temperature lithium-ion conductivity (9.85 × 10⁻⁴ S⋅cm⁻¹), high lithium-ion transfer number (0.63), wide electrochemical window (4.9 V vs Li⁺/Li). The Li|Li symmetric battery assembled with 5 wt% BaTiO₃ can be stably circulated for 800 h at 0.1 mA⋅cm⁻², and the LiFePO₄|CSE|Li battery maintains a capacity retention of 86.2% after 50 cycles at a rate of 0.3 C. The influence of BaTiO₃ ceramic powder on the properties of PAN-based polymer electrolytes is analyzed. Our results provide a new avenue for future research in the all-solid-state lithium battery technology.