Research Progress of Silicon Suboxide-Based Anodes for Lithium-Ion Batteries

With unique advantages, such as high energy density, long lifespan and environmental friendliness, lithium-ion batteries (LIBs) have been widely used in various portable electronics, and placed great expectations on the application in electric vehicles. To meet the ever-increasing high-energy-density demand of the next-generation LIBs, silicon suboxide SiO_x(0 < x < 2) has been considered as one of the most promising anode materials, due to its high mass specific capacity, good cycling performance, proper working potential, low cost, and environmental friendliness. However, there are still several drawbacks before the application of SiO_x, such as low intrinsic electronic conductivity and high irreversible capacity in the first cycle, which lead to low electrochemical activity and low initial coulombic efficiency (ICE). To tackle these issues, extensive efforts have been made and remarkable progresses have achieved in recent years. Here, latest developments of SiO_x-based anodes are briefly reviewed, especially on the subject of metal/metal oxide doping on SiO_x-based electrode materials, and the future application of SiO_x anodes in rechargeable LIBs is also prospected.