FIRST-PRINCIPLES COMPUTATIONAL INSIGHTS INTO SILICON-BASED ANODE MATERIALS: RECENT PROGRESS AND PERSPECTIVES

Abstract

Silicon-based material is one of the most promising substitutes for commercial graphite anodes for the next generation lithium-ion batteries due to its extremely high theoretical capacity. However, the huge volume changes during the charging and discharging processes will cause rapid capacity decay and a short cycle life. Developing novel silicon-based materials requires a fundamental understanding of their properties. However, in many cases, the present experiments are incapable of completely mimicking real battery-operation conditions, and detailed information about the electrochemical mechanisms and ion and electron kinetic transport at the electrode/electrolyte interface is still ambiguous due to their complexity. First-principles calculations have become an effective method for predicting and interpreting the characteristics of electrode materials, understanding the electrochemical mechanisms at the atomic scale and delivering rational design strategies for electrode materials. In this review, the first-principles calculations of silicon-based anode materials in recent years, based on different modification strategies, are summarized. First, we introduce the diffusion kinetics of lithium ions in silicon and the mechanism of structure changes during the lithiation process. Then, typical examples of novel Si-based anodes, including 2D nanomaterials, silicide materials and coating materials based on theoretical predictions, are presented. Finally, we provide perspectives and future directions of first-principles calculations on Si-based anodes.