EGaIn coated 3D-Cu foam as a self-healing current collector for lithium ion batteries

• A self-healing current collector is obtained via combining EGaIn and 3D-Cu foam. • The formed self-healing graphite anode shows a specific capacity of 328 mA h g −1 . • The self-healing graphite anode shows a retention of 94.2% after scratch damage. • The EGaIn@3D-Cu current collector could enhance cycling stability of electrode. Traditional lithium-ion batteries are prone to cracks and perforations in extreme environments, which could cause electrochemical performance degradation or even safety problems. Here, based on the alloying reaction of liquid metal, through the adjustment of alloying temperature and reaction time, a uniform and stable dispersion of eutectic gallium indium liquid metal (EGaIn) on the surface and internal structure of the micro-etched 3D-Cu current collector (EGaIn@3D-Cu) is obtained. Furthermore, the graphite anode prepared with the EGaIn@3D-Cu current collector (the self-healing graphite anode) shows an excellent self-healing performance. Namely, the specific capacities of the self-healing graphite anode before and after scratch damage are 327.4 mA h g −1 and 309.6 mA h g −1 , respectively, which is significantly better than that of the graphite anode assembled with 2D-Cu foil current collector. Therefore, the EGaIn@3D-Cu current collector prepared by a simple manufacturing process could effectively realizes the self-healing function, prevent the capacity degradation and improve the stability of the battery.