Electric Field-Induced Fast Li-Ion Channels in Ionic Plastic Crystal Electrolytes for All-Solid-State Batteries

Abstract

The practical use of all-solid-state batteries (ASSBs) is hindered by the intractable electrolyte/electrode interfacial resistance and discontinuous ion transport networks within electrodes. Ionic plastic crystals offer a potential solution to these challenges due to their melt-permeable properties to the electrodes. However, their limited ionic conductivity restricts their application. Here, we propose a design principle for solid-state electrolytes based on an electric field-induced strategy by using ionic plastic crystals with low self-migrating and high conductivity toward target ions. Through the external potential difference, an ordered internal electric field is generated within the ionic plastic crystal-based solid-state electrolytes (IPCEs), which mitigates the coordination limitations of anions on target ions to facilitate rapid ion conduction. The prepared IPCE demonstrates high ionic conductivity (1.08 × 10⁻³ S cm⁻¹ at 25 °C) and a Li⁺ transfer number (0.77), enabling the application of ASSBs over a wide temperature range (from 0 to 60 °C). Furthermore, the assembled Li||LiNi_0.8Co_0.1Mn_0.1O₂ ASSBs exhibit stable cycling, maintaining 97.5% capacity retention after 500 cycles at 25 °C. This work provides a fresh perspective on the practical application of ASSBs, highlighting the potential of IPCEs in enhancing battery performance.