Revival of Microparticular Silicon for Superior Lithium Storage

The development of high-performance electrode materials is a long running theme in the field of energy storage. Silicon is undoubtedly among the most promising next-generation anode material for lithium batteries. Of particular note, the use of nano-Si, as the milestone advance, has opened the door of the commercialization of silicon, but is still hindered by issues related to cost, side reactions, and volumetric performance. Micro-Si, competed unsuccessfully with nano-Si long ago, but now has returned with its natural strengths in low cost, high tap density, and low interfacial reaction, and is regaining attention both from academia and industry. In this review, the promises of micro-Si anodes are first clarified and then their pain points are presented followed by a summary of the potential remedies such as carbon encapsulation, binder design, and electrolyte modifications with improved mechanical and electrochemical stability. Finally, toward practical use of micro-Si in future lithium batteries, major prospective directions are discussed. Carbon coatings with desired mechanical properties combined with a stable solid electrolyte are highlighted along with with their practical significance to exploit micro-Si anodes.