Fundamental Understanding of the Low Initial Coulombic Efficiency in SiOx Anode for Lithium-Ion Batteries: Mechanisms and Solutions.

Abstract

To meet the ever-increasing demand for high-energy lithium-ion batteries (LIBs), it is imperative to develop next-generation anode materials. Compared to conventional carbon-based anodes, Si-based materials are promising due to their high theoretical capacity and reasonable cost. SiOx, as a Si-derivative anode candidate, is particularly encouraging for its durable cycling life, the practical application of which is, however, severely hindered by low initial Coulombic efficiency (ICE) that leads to continuous lithium consumption. What is worse, low ICE also easily triggers a terrible chain reaction causing bad cycling stability. To further develop SiOx anode, researchers have obtained in-depth understandings regarding its working/failing mechanisms so as to further propose effective remedies for low ICE mitigation. In this sense, herein recent studies investigating the possible causes that fundamentally result in low ICE of SiOx, based on which a variety of solutions addressing the low ICE issue are discussed and summarized, are timely summarized. This perspective provides valuable insights into the rational design of high ICE SiOx anodes and paves the way toward industrial application of SiOx as the next generation LIB anode.