Self-Healing Silicon Anode via the Addition of GaInSn-Encapsulated Microcapsules

Abstract

Silicon materials as promising anodes for lithium-ion batteries own a high specific capacity and a low discharge potential, while their application is restricted by their huge volumetric expansion and poor conductivity. In this study, a self-healing GaInSn–MS/Si hybrid electrode using an additive of microencapsulated gallium- liquid metal (GaInSn) with high electrical conductivity and mobility (LM microcapsule) was fabricated via an aqueous casting process. With the added LM microcapsule in the GaInSn–MS/Si hybrid electrode, the dispersed GaInSn could not only avoid its oxidation into a solid-state gallium oxide with decreased conductivity but also make it easy for uniform dispersion and quick fluidity. Consequently, the constructed self-healing GaInSn–MS/Si anode does not require manual splicing when the anode forms cracks, realizing a spontaneous self-healing performance, and the GaInSn–MS/Si hybrid electrode displays superior cycle stability and structural integrity, which retains a capacity of 806.7 mAh g–1 after 100 cycles at 2.1 A g–1. The constructed self-healing Si electrode structure design via LM microcapsule additives would provide a simple synthesis strategy for manufacturing advanced Si electrodes.