LiAlCl4·3SO2 as a high conductive, non-flammable and inorganic non-aqueous liquid electrolyte for lithium ion batteries

Safety problems of lithium ion batteries (LIBs), such as fire and explosion caused by flammable commercial organic electrolyte (OE) during abuse-testing conditions, hinder the further application of LIBs. To address these issues, an inorganic non-aqueous liquid electrolyte-LiAlCl4·3SO2 (IE) was synthesized and investigated for LIBs. This study demonstrated that the IE possessed preeminent comprehensive properties, such as non-flammable property, sufficient ionic conductivity (23.77 mS cm−1 at room temperature) and high lithium ion transport number (tLi+=0.47). Therefore, compared with OE, LiFePO4 (LFP) cathode in IE exhibited outstanding rate capacity and stable cycle performance at room temperature. At room temperature the discharge capacity of LFP in IE could still achieved ∼80 mAh·g−1 at 10 C, while the reversible capacities of LFP in OE is almost 0 mAh·g−1. In addition, at 0 °C the reversible capacities of LFP in IE is much higher than the LFP in OE, and graphite electrode with IE also shows better rate capabilities than graphite electrode with OE. All these results demonstrate that the presented IE could be served as a good electrolyte candidate for LIBs.