Unveiling Interfacial Corrosion of Ga-Based Liquid Metal Alloys in Lithium Metal Batteries.

Ga-based liquid metals (LMs) are effective materials for maintaining the structural stability of Li-ion battery electrodes because of their conductive, soft, self-healing, and nontoxic properties. When used as an artificial interface for Li metal anodes, this interface promotes lithiophilic and structurally uniform Li deposition, extending battery lifespan. However, the high reactivity of Ga with other metals can lead to alloy formation while also causing corrosion and rapid interfacial changes upon contact. Furthermore, in eutectic alloys (such as GaIn and GaInSn), segregation of individual metal components occurs. Here, this study investigates the previously overlooked issue of Ga-based LM corrosion on anode current collectors and analyzes its impact on Li metal battery lifespan from structural, chemical, and electrochemical perspectives. These findings open up a new direction for the application of LMs to Li-ion batteries and will contribute to the design of next-generation Li metal batteries.