Enabling Uniform and Stable Lithium‐Ion Diffusion at the Ultrathin Artificial Solid‐Electrolyte Interface in Siloxene Anodes

Abstract

AbstractConstructing a stable and robust solid electrolyte interphase (SEI) has a decisive influence on the charge/discharge kinetics of lithium‐ion batteries (LIBs), especially for silicon‐based anodes which generate repeated destruction and regeneration of unstable SEI films. Herein, a facile way is proposed to fabricate an artificial SEI layer composed of lithiophilic chitosan on the surface of two‐dimensional siloxene, which has aroused wide attention as an advanced anode for LIBs due to its special characteristics. The optimized chitosan‐modified siloxene anode exhibits an excellent reversible cyclic stability of about 672.6 mAh g−1 at a current density of 1000 mA g−1 after 200 cycles and 139.9 mAh g−1 at 6000 mA g−1 for 1200 cycles. Further investigation shows that a stable and LiF‐rich SEI film is formed and can effectively adhere to the surface during cycling, redistribute lithium‐ion flux, and enable a relatively homogenous lithium‐ion diffusion. This work provides constructive guidance for interface engineering strategy of nano‐structured silicon anodes.