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

LiAlCl4 center dot 3SO(2) 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 center dot 3SO(2) to achieve favorable protection for Li metal anodes. Here, Li|Cu cells with SO2-based inorganic electrolyte (LiAlCl4 center dot 3SO(2)) 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 center dot 3SO(2) electrolyte can reach 95% at - 20 degrees C, while the coulombic efficiency of the conventional organic electrolyte at - 20 degrees C is only about 79%. Furthermore, LiAlCl4 center dot 3SO(2) electrolyte is non-combustible. Based on all the experimental results, LiAlCl4 center dot 3SO(2) is a promising electrolyte candidate for safe Li metal batteries. Graphic abstract Lithium metal anode, protected by the stable and dense SEI films formed in non-flammable and inorganic non-aqueous liquid electrolyte-LiAlCl4 center dot 3SO(2) (IE), exhibits small and stable over-potential during Li stripping/plating compared with conventional organic electrolyte (OE) even at - 20 degrees C.