A LiPO 2 F 2 /LiPF 6 dual-salt electrolyte enabled stable cycling performance of nickel-rich lithium ion batteries.

In this work, a dual-lithium salt was proposed for constructing an electrolyte for high energy density lithium ion batteries. LiPO 2 F 2 was composed with traditional LiPF 6 to enhance the high voltage performance of the electrolyte. The electrochemical performance of the NCM811/Li cells with LiPO 2 F 2 /LiPF 6 dual-lithium salt at 2.8-4.5 V was investigated. It was found that the dual-lithium salt can inhibit the oxidative decomposition of the electrolyte, suppress the dissolution of the transition metal ions in the electrode material, and reduce the side reaction between the transition metal ions and the electrolyte. We believe that the strategy of a dual-lithium salt electrolyte may provide a new idea to stabilize the electrode/electrolyte interface at high voltage, which is very important for developing high energy density batteries.