Highly mesoporous silicon derived from waste iron slag for high performance lithium ion battery anodes

Abstract

Recycling waste iron slag to produce a high value-added product is of crucial importance to the steel industry, in terms of waste management, as well as to other industries searching for more attractive raw materials. Herein, we report a novel and facile approach to synthesize highly mesoporous silicon derived from waste iron slag. Simple acid leaching of iron slag leads to the generation of mesopores, and a subsequent magnesiothermic reaction with sodium chloride converts silica to silicon without the collapse of the nanostructure. Owing to the three-dimensionally interconnected and highly porous structure with a small crystallite size (similar to 10 nm), the converted mesoporous silicon, when used as a Li-ion battery anode, exhibits superior cycle performance and rate capability, compared with commercial silicon materials. We expect the synthesis of nanostructured silicon by recycling waste iron slag and its successful application to open up new avenues in the field of sustainable industrial development.