Diverting Exploration of Silicon Anode into Practical Way: A Review Focused on Silicon-Graphite Composite for Lithium Ion Batteries

With the increasing need for maximizing the energy density of energy storage devices, silicon (Si) active material with ultrahigh theoretical capacity has been considered as promising candidate for next-generation anodes in lithium ion batteries (LIBs). However, their practical application has always been hindered by suppressed electrochemical properties, which arise from large volume changes and deteriorated electrode architecture during cycling process. Notably, recent developments have demonstrated that silicon active materials incorporated with tough graphite frameworks are very promising electrode candidates for efficient lithium storage devices, taking advantage of the high theoretical capacity of Si and ultrahigh stability of graphite. In this review, the necessity of co-exploitation of silicon and graphite is highlighted, and representative silicon-graphite anodes along with various approaches for composite construction are organized. Moreover, critical issues, challenges, and perspectives of the Si-graphite electrodes are also systematically concluded and presented. With a deep understanding of associated electrochemical processes, the component and structural optimization of Si-graphite anodes could be effectively enhanced.