A High-Performance Room-Temperature Li||Ga-Sn Liquid Metal Battery For Grid Energy Storage

Herein, a room-temperature liquid metal battery (LMB) with a solid lithium anode electrode and gallium-tin (Ga-Sn) alloy cathode electrode is reported. With the improved wettability of the electric collector and grain-refined liquid metal droplets cathode, the aforementioned LMB exhibits good cyclic reversibility and negligible self-discharge. The result shows that the assembled Li||Ga-Sn battery has a satisfactory specific capacity (409 mAh g(-1)) and high energy efficiency (up to 92%). The low melting point Ga-Sn alloy can construct fast kinetics for the redox reaction and improve the electrode reaction kinetics, imparting the Li||Ga-Sn system with high discharge voltage (0.77 V at 1C) and smaller polarization voltage at different current densities, which ensure the high Coulomb efficiency and good rate performance of the battery. Moreover, the battery stably cycles at 35 degrees C for 60 cycles at the 1C rate, with no significant capacity degradation. With good electrochemical performance, simple structure, easy maintenance, and high safety, this room-temperature Li||Ga-Sn battery may be a promising choice for power grid energy storage applications.