Boosting Cyclability and Rate Capability of SiO x via Dopamine Polymerization-Assisted Hybrid Graphene Coating for Advanced Lithium-Ion Batteries.

SiO x suffers from the 200% volume change during cycling and low electronic conductivity, resulting in poor cyclability and rate capability as a lithium-ion battery anode. Herein, we demonstrate a dopamine polymerization-guided carbon coating for SiO x anodes (SiO x @PDA@GNH). SiO x @PDA@GNH delivers charge capacities of 1269 and 1140 mA h·g -1 at charge rates of 0.05 and 3 C, respectively, and a capacity retention of 79.60% after 150 cycles at 1 C. A full cell with LiNi 0.8 Co 0.1 Mn 0.1 O 2 or cathode demonstrates a capacity retention of >80% after 100 cycles at the rate of 0.33 C with an area capacity over 3.2 mA h·cm -2 . Suppressed crack and overgrowth of the SEI layer are the key contributions for the improved performance. These results enlighten a practical pathway for the designing and modifications of SiO x anodes for high energy density lithium-ion batteries.