Tailored Carrier Transport Path by Interpenetrating Networks in Cathode Composite for High Performance All-Solid-State Li-SeS2 Batteries

All-solid-state Li-SeS(2 )batteries (ASSLSs) are more attractive than traditional liquid Li-ion batteries due to superior thermal stability and higher energy density. However, various factors limit the practical application of all-solid-state Li-SeS2 batteries, such as the low ionic conductivity of the solid-state electrolyte and the poor kinetic property of the cathode composite, resulting in unsatisfactory rate capability. Here, we employed a traditional ball milling method to design a Li7P2.9W0.05S10.85 glass-ceramic electrolyte with high conductivity of 2.0 mS cm(-1) at room temperature. In order to improve the kinetic property, an interpenetrating network strategy is proposed for rational cathode composite design. Significantly, the disordered cathode composite with an interpenetrating network could promote electronic and ionic conduction and intimate contacts between the electrolyte-electrode particles. Moreover, the tortuosity factor of the carrier transport channel is considerably reduced in electrode architectures, leading to superior kinetic performance. Thus, assembled ASSLS exhibited higher capacity and better rate capability than its counterpart. This work demonstrates that an interpenetrating network is essential for improving carrier transport in cathode composite for high rate all-solid-state Li-SeS2 batteries.

Automated summary

All-solid-state Li-SeS2 batteries have advantages in thermal stability and energy density compared to traditional liquid Li-ion batteries. However, the low ionic conductivity of the solid-state electrolyte and poor kinetic property of the cathode composite limit their practical application. In this study, a high conductivity Li7P2.9W0.05S10.85 glass-ceramic electrolyte was designed using a traditional ball milling method, and an interpenetrating network strategy was proposed for rational cathode composite design. The assembled batteries showed improved capacity and rate capability, demonstrating the importance of an interpenetrating network for carrier transport in cathode composite.