Self-Healing\nLiquid Metal and Si Composite as a High-Performance Anode for Lithium-Ion\nBatteries

Abstract

Si\nis among the highest theoretical capacity anodes for lithium-ion batteries,\nbut it suffers from huge volume expansion during lithiation. Here\nwe report a new approach to alleviating the volume change-induced\ndegradation of Si anodes by mixing Si with a room-temperature liquid\nmetal (LM), namely, Ga–Sn alloy. The Ga–Sn alloy is\nfluid with self-healing ability, acting as the liquid buffer for the\nSi upon lithiation and delithiation and healing the cracks caused\nby the volume expansion and contraction. The resulting Si/LM composite\nexhibits a high capacity and excellent cyclicability. The composite\nanode delivers a reversible capacity of ∼670 mAh/g after 1000\ncycles, with an outstanding rate capability.