A Superior Carbonate Electrolyte for Stable Cycling Li Metal Batteries Using High Ni Cathode

Li metal batteries pairing Li metal anode with high-nickel layer structured oxide cathode are a promising energy storage technology to achieve high energy density. To obtain long cycling life for Li metal batteries, the electrolyte plays a pivotal role in stabilizing both the Li metal anode and the high-nickel cathode upon electrochemical cycling. Herein, we report a carbonate electrolyte that enables a Li∥LiNi0.8Mn0.1Co0.1O2 pouch cell to achieve a high gravimetric energy density of 366 Wh/kg and unprecedented cycling stability with 80% capacity retention after 335 cycles. The 19F quantitative nuclear magnetic resonance spectroscopy and interface characterization demonstrate that FEC and LiDFOB can reduce the consumption rate of each other and the electrolyte, form a robust LiF-rich SEI on Li metal anode, and improve the microstructure integrity of the high-nickel cathode.