High-Performance Silicon Anodes Enabled By Nonflammable Localized High-Concentration Electrolytes

Silicon anodes are regarded as one of the most promising alternatives to graphite for high energy-density lithium-ion batteries (LIBs), but their practical applications have been hindered by high volume change, limited cycle life, and safety concerns. In this work, nonflammable localized high-concentration electrolytes (LHCEs) are developed for Si-based anodes. The LHCEs enable the Si anodes with significantly enhanced electrochemical performances comparing to conventional carbonate electrolytes with a high content of fluoroethylene carbonate (FEC). The LHCE with only 1.2 wt% FEC can further improve the long-term cycling stability of Si-based anodes. When coupled with a LiNi0.3Mn0.3Co0.3O2 cathode, the full cells using this nonflammable LHCE can maintain >90% capacity after 600 cycles at C/2 rate, demonstrating excellent rate capability and cycling stability at elevated temperatures and high loadings. This work casts new insights in electrolyte development from the perspective of in situ Si/electrolyte interphase protection for high energy-density LIBs with Si anodes.