In Situ Inorganic-Rich Electrode–Electrolyte Interphases for Safer 4.5 V Gr||NCM811 Batteries Enabled by an Ethylene Carbonate-Free Electrolyte

Safety concerns represented by thermal runaway (TR) have seriously hindered the further development of high-energy lithium-ion batteries. In this work, we designed robust inorganic-rich electrode–electrolyte interphases on the single-crystal LiNi0.8Co0.1Mn0.1O2 cathode and graphite anode via adopting an ethylene carbonate (EC)-free electrolyte, which can decrease the side reaction between electrodes and electrolytes. Ultimately, the cell employing the EC-free electrolyte can maintain 96% of the initial capacity after 300 cycles at 4.5 V, while only 73% of the initial capacity can be retained for the cell with the conventional electrolyte. The safety test indicates that the trigger temperature of TR decreased by 59.6 °C, the maximum temperature decreased by 40 °C, and the maximum temperature increase rate fell by 4380 °C/min after being infused with the EC-free electrolyte. The designed robust inorganic-rich electrode–electrolyte interphases combined with the EC-free electrolyte can effectively suppress the release of heat flow and gas, which provides guidelines for safer high-energy batteries.