Liquid Metal-Induced Self-Healing Interface and 3D Porous Configuration Enable a High-Performance Si/Carbon Anode for Lithium-Ion Storage.

Abstract

Ga-based liquid metals (LMs) have emerged as pivotal materials for optimizing the electrochemical performance of electrode materials due to their intrinsic dynamic adaptability, self-healing capability, and exceptional conductivity. However, conventional LM fabrication methods typically produce oversized particulates, resulting in poor lithium-ion diffusivity. Herein, we designed a three-dimensional porous silicon/carbon composite (GaIn-Si@PCC) through a dual-carbon precursor strategy combined with freeze-drying and a thermal reduction process, where silicon nanoparticles were well encapsulated into a porous carbon framework decorated with GaIn LMs. The GaIn phase dynamically alleviates lithiation-induced stress via plastic deformation and enables crack self-healing during delithiation, synergizing with the robust carbon skeleton to ensure structural integrity. Theoretical calculations further reveal that GaIn LMs optimize Li⁺ adsorption-diffusion equilibrium, while the continuous conductive network collectively enhances ion/electron transport kinetics, thereby obtaining a stable and inorganic-rich solid electrolyte interphase interface. Consequently, the GaIn-Si@PCC anode delivers a high initial Coulombic efficiency (87.3%) and exceptional cycling stability (1595.4 mAh g^-1 after 200 cycles at 0.2 A g^-1). When paired with a commercial NCM811 cathode, the full cell maintains 86.8% capacity retention after 100 cycles at 0.5C. This work provides a multiscale design paradigm combining dynamic stress management and ion regulation for high-performance silicon-based energy storage systems.