In Situ Construction of S-Based Artificial Solid Electrolyte Interphases Layer for Stable Silicon Anode in Lithium-Ion Batteries

Silicon is the most widely used anode material for high-energy lithium-ion batteries because of its high capacity and abundant reserves. Nevertheless, the huge volume change of silicon during cycling can cause severe structural damage and instability of the solid electrolyte interphase (SEI), thus leading to rapid capacity fading and poor Coulombic efficiency. Herein, an S-containing artificial SEI layer (S-ARSEI) was designed on the silicon surface via the nucleophilic reaction between polysulfides and ester electrolyte, which greatly alleviates its volume expansion and improves the Li+ transport. The silicon anode coated by an S-ARSEI layer maintains a reversible specific capacity of 1387 mA h g–1 at 0.5 C after 500 cycles with a capacity retention of 70%. It also exhibits an excellent rate performance of 1200 mA h g–1 at 2 C. This work provides a new design of an S-containing SEI layer for the volume expansion electrodes for the secondary batteries.