Bismuth and Chlorine Dual-Doped Perovskite Chloride as a Phase-Structure-Stable and Moisture-Resistant Solid Electrolyte for Chloride Ion Batteries

Perovskite chloride, an anion conductor, is a promising candidate to be a solid electrolyte for high-energy and sustainable chloride ion batteries (CIB). However, it suffers from poor structural stability at low temperature and in ambient conditions, which leads to its transformation from an ionic conductor to an insulator. Herein, a bismuth and chlorine dual doping strategy is developed to stabilize the cubic structure of CsSnCl3 in harsh environments. The as-prepared dual-doped CsSn0.9Bi0.1Cl3.1 material with an optimized composition maintains its cubic structure at the extremely low temperature of 213 K for 10 days and at 40% relative humidity for 50 days, while the undoped cubic material deteriorates and transforms to a monoclinic phase under these conditions in less than 1 day. Consequently, the dual doping achieves efficient chloride ion conduction that is superior to single bismuth doping due to the introduction of interstitial chlorine facilitating chloride ion transport. Importantly, the practicality of the as-prepared solid electrolyte is demonstrated in different symmetric solid cells and by various CIBs using the organic electrode couple, a multivalent metal chloride cathode, or a new high-voltage metal oxychloride cathode. A bismuth and chlorine dual doping approach is developed to stabilize the cubic structure of perovskite chloride against the extremely low temperature of 213 K and ambient conditions with 40% relative humidity for a long period, thereby yielding the cubic CsSn0.9Bi0.1Cl3.1 solid electrolyte with efficient chloride ion conduction in different symmetric solid cells and various rechargeable chloride ion batteries.image

Automated summary

A dual doping approach using bismuth and chlorine is developed to stabilize the structure of perovskite chloride and achieve efficient chloride ion conduction. The as-prepared dual-doped material maintains its cubic structure under low temperature and high humidity conditions, showing superior performance in various battery systems.