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 degrees C, the maximum temperature decreased by 40 degrees C, and the maximum temperature increase rate fell by 4380 degrees 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.

Automated summary

This study successfully improves the safety and cycle life of high-capacity lithium-ion batteries by designing stable inorganic-rich electrode-electrolyte interphases and adopting an EC-free electrolyte.