有色设备

The unsatisfactory performance of single inorganic and organic solid electrolytes has driven the development of composite solid electrolytes (CSEs) for solid-state lithium batteries (SSLBs). However, the existence of lithium-depleted space charge layers (SCLs) at the interface of cathode and CSEs (I_C—C) restricts lithium ion transport, which hinders the improvement of ionic conductivity and affects the electrochemical performance of SSLBs. Herein, we report a new type of solid electrolyte composite with bismuth ferrite (BiFeOs). Its presence weakens the lithium-depleted SCLs at the I_C—C, activates lithium ion transport channels, and enables efficient diffusion of lithium ions across various internal interfaces of solid-state batteries. This design achieves a high ionic conductivity of 1.24 mS cm^-1and a high lithium ion transference number of 0.81, which are approximately twice as high as those without BiFeO₃. Consequently, the all-solid-state lithium battery using LiNi_0.9Co_0.05Mn_0.05O₂ cathode exhibits excellent electrochemical performance, retaining 92.3% of its capacity after 200 cycles at 0.5C. This innovation of activating lithium ion transport channels at the interface by weakening lithium-poor SCLs provides a new approach for achieving high-performance composite solid electrolytes and solid-state lithium batteries.