Porous Silicon-Carbon Composite Materials Engineered by Simultaneous Alkaline Etching for High-Capacity Lithium Storage Anodes

Abstract

Porous silicon-carbon (Si-C) composite materials have attracted a great deal of attention as high-performance anode materials for Li-ion batteries (LIBs), but their use suffers from the complex and limited synthetic routes for their preparation. Herein we demonstrate a scalable and nontoxic method to synthesize porous Si-C composite materials by means of simultaneous chemical etching of Si and carbon phases using alkaline solution. The resulting porous Si-C composite material showed greatly improved cycle performance, good rate capability, and high dimensional stability during cycling. Porous Si-C electrode showed an expansion of the height by about 22% after the first lithiation and only 16% after the first cycle. The material synthesis concept and scalable simultaneous etching approach presented here represent a means of improving the electrochemical properties of Si-based porous anode materials for use in commercial LIBs. (C) 2016 Elsevier Ltd. All rights reserved.