Design of active-material/solid-electrolyte composite particles with conductive additives for all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSLIBs) are promising candidates for next-generation electric vehicle batteries. The contact interface between the active material (AM) and solid electrolyte (SE) is an important factor that affects the performance of ASSLIB. Composite particles, which are SE-coated AM particles, can form electrodes with large AM-SE contact interfaces. However, they can decrease in cell capacity because of the SE coating layer with electrical non-conductance. This study designed composite particles with conductive additives (CAs) using dry-coating. Acetylene black (AB) and vapor-grown carbon fiber (VGCF) were used as typical CAs, and the composite particles with these CAs were compared with those without CAs and simple mixture. Although the addition of CAs improved the cell capacity and decreased internal resistance, the type of CA significantly affected the rate performance. Because the VGCFs were barely incorporated into the SE coating layer, the incorporation of VGCFs did not improve the rate performance. However, the ABs were effectively incorporated into SE coating layer, resulting in the best rate performance in this study. This difference was due to the ease of supplying electrons to the AM particles. Therefore, AB was suitable for the CA of the composite particles to improve the performance of the ASSLIB.

Automated summary

Composite particles with conductive additives were designed for all-solid-state lithium-ion batteries (ASSLIBs) using dry-coating. The addition of conductive additives improved the cell capacity and decreased internal resistance, with acetylene black (AB) showing the best rate performance. The type of conductive additive significantly affected the rate performance, with vapor-grown carbon fiber (VGCF) not improving the rate performance due to its limited incorporation into the solid electrolyte coating layer.