LiAlCl4·3SO2: a promising inorganic electrolyte for stable Li metal anode at room and low temperature

Abstract

LiAlCl4·3SO2 is a promising electrolyte used for Li metal batteries. At room and low temperature, a stable solid electrolyte interface film can be formed in LiAlCl4·3SO2 to achieve favorable protection for Li metal anodes. Here, Li|Cu cells with SO2-based inorganic electrolyte (LiAlCl4·3SO2) display higher average coulombic efficiency and more excellent cycling stability compared with a conventional organic electrolyte. Moreover, at 0.5 mA cm−2, the coulombic efficiency of Li|Cu cells with LiAlCl4·3SO2 electrolyte can reach 95% at − 20 °C, while the coulombic efficiency of the conventional organic electrolyte at − 20 °C is only about 79%. Furthermore, LiAlCl4·3SO2 electrolyte is non-combustible. Based on all the experimental results, LiAlCl4·3SO2 is a promising electrolyte candidate for safe Li metal batteries.