Bismuth oxychloride nanoflake assemblies as a new anode for potassium ion batteries

This work reports the first demonstration of bismuth oxyhalides as anode materials in potassium-ion batteries. BiOCl nanoflake assemblies deliver high capacities of 367 mA h g(-1) at 50mA g(-1) and 175 mA hg(-1) at 1 A g(-1). The formation of K-Bi alloys at an early stage of potassiation is observed.