Electrolyte, method for improving high-temperature performance of lithium ion battery and lithium ion battery

The invention discloses an electrolyte, a method for improving the high-temperature performance of a lithium ion battery and the lithium ion battery. The electrolyte comprises a lithium salt, an organic solvent and an additive, wherein the additive comprises magnesium bis (oxalato) borate. The additive magnesium bis (oxalato) borate and the magnesium bis (oxalato) borate are added into a conventional electrolyte system as a high-temperature additive, a high-temperature-resistant solid electrolyte interface film is formed on the surface of the positive electrode material, dissolution of metal ions of the positive electrode material can be effectively inhibited, and the high-temperature performance of the battery is further effectively improved. 本申请公开了一种电解液、改善锂离子电池高温性能的方法及锂离子电池。所述电解液包括：锂盐、有机溶剂以及添加剂，添加剂包括双草酸硼酸镁。本申请的添加剂双草酸硼酸镁，双草酸硼酸镁作为高温添加剂添加到常规电解液体系中，在正极材料表面形成耐高温的固态电解质界面膜，可以有效抑制了正极材料的金属离子的溶出，进而有效改善电池的高温性能。