Molten Salt Electrosynthesis of TiC-Derived Carbon Catalysts for High-Performance Lithium-Oxygen Batteries.

The development of efficient bifunctional catalysts to improve the kinetics of oxygen electrode reactions is a critical challenge in realizing high-performance, long-life lithium-oxygen batteries. Herein, TiC was successfully synthesized via a molten salt electrolysis method, followed by the preparation of a series of TiC-derived carbon (TiC-xCDC, x = 10, 30, 60) composites by adjusting the electrolytic time after electrode exchange. The formation of derived carbon effectively addresses the issue of TiC agglomeration and significantly enhances the electrical conductivity of the composite. Particularly, the TiC-30CDC composite not only exhibits a large specific surface area and an abundant mesoporous structure, providing ample storage space for discharge products, but also facilitates ion and electron transport efficiency. Moreover, the electrochemical stability and robust catalytic performance of TiC further promote the kinetics of the oxygen electrode reaction, resulting in excellent electrochemical performance in lithium-oxygen batteries. At a current density of 500 mA g^-1, the TiC-30CDC cathode demonstrates an impressive specific discharge capacity of up to 15,081.9 mAh g^-1. At the same current density with a defined specific capacity of 1000 mAh g^-1, the cathode can operate stably for 430 cycles while maintaining low discharge/charge overvoltage levels (2.49 V/4.45 V) even after nearly 1800 h of cycling. The air electrode prepared through molten salt electrolysis offers an innovative and feasible approach for the design and mass production of other metal-air cathodes due to its significant cost-effectiveness and environmental friendliness.