Progress and perspectives of space charge limited current models in all-solid-state batteries

All-solid-state batteries (ASSBs) have been considered next-generation energy storage. However, space charge layers (SCLs) at solid-solid interfaces due to Li chemical potential difference between electrode/ electrolyte materials are essential to understanding the charge transfer of ASSBs. However, the influence of SCL on the Li-ion transport between interfaces is unclear because of the difficulty of distinguishing the impedance contribution of SCL towards the ionic transport from other effects. This review summarizes the various conclusions of the SCL effect and its impact on interface charge transfer resistance. We have proposed that further investigation of SCL in the full cell and bipolar stack cell is required for developing high-performance ASSBs. Moreover, we highlight the development and application of the electrochemical-based P2D model, which considered the SCL parameter for the simulation, and space charge limited current models for investigating Li-ion transport across the interface are needed to fully understand the SCL effect in ASSBs