Self-healing liquid metal-rGO anode via self-assembly driven dynamic encapsulation for stable lithium-ion storage

Lithium-ion batteries have become dominant in the markets for portable electronic devices and electric vehicles owing to their high energy density and long cycle life. However, traditional alloy-based anode materials (such as Si, Bi, and Sn) still suffer from significant volume expansion, severe electrode pulverization, slow lithium diffusion kinetics, and low Coulombic efficiency. Intrinsic high-capacity liquid metal (LM) materials effectively mitigate the volume deformation of traditional alloy anodes during cycling through their unique deformable liquid properties. Specifically, during delithiation, the ternary alloy solid phase reversibly transforms into a binary liquid structure, and the phase transformation behavior endows the material with self-healing ability, which can spontaneously repair the cracks or pulverized structures generated during cycling. This study proposes a self-assembled dynamic encapsulation strategy based on a GaSn eutectic alloy (EGaSn), in which liquid metal nanodroplets are encapsulated via the liquid-phase self-assembly of graphene oxide (GO). The resulting LM-rGO anode exhibits excellent specific capacity (779.29 mAh g⁻¹ after 100 cycles at 0.5 A g⁻¹) and outstanding cycling stability (453.77 mAh g⁻¹ after 500 cycles at 2 A g⁻¹). The encapsulation strategy not only mitigates the volume expansion effect of alloy-based anodes but also enhances the lithium-ion transport kinetics through the synergy between its unique stress-buffering mechanism and the three-dimensional conductive network. This strategy provides an innovative solution for the development of high-performance lithium-ion batteries with self-healing functionalities.