Improving Electrochemical Performance of Thick Silicon Film Anodes with Implanted Solid Lithium Source Electrolyte

Silicon is a potential next-generation anode material for a lithium-ion battery. However, the large-scale application of silicon is restricted by poor electrical conductivity, large volume change, and high irreversible capacity during the charge/discharge process. Here, we proposed a simple strategy by preimplanting a solid lithium source electrolyte (Li₂CO₃ and Li₂O) into Si thick film to improve the electrochemical properties of Si materials. The implanted solid lithium source electrolyte participates in and induces the formation of SEI not only on the top surface of Si film but also in the interface of Si particles. The thick Si film with the implanted solid lithium electrolyte (a thickness of ∼10 μm) delivers above 2000 mAh g^-1 specific capacity, >92% initial Coulombic efficiency, and ∼87% capacity retention over 150 cycles at 400 mA g^-1. The present work sheds light on the design of high capacity and long cycle life electrode materials for other batteries.