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

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. [Figure not available: see fulltext.].