Regulate the Solvation Structure and Interface by Nitrate in Phosphate‐Based Electrolytes for 4.5 V‐Class Ni‐Rich Batteries

Abstract Phosphate‐based electrolyte propels the advanced battery system with high safety. Unfortunately, restricted by poor electrochemical stability, it is difficult to be compatible with advanced lithium metal anodes and Ni‐rich cathodes. To alleviate these issues, the study has developed a phosphate‐based localized high‐concentration electrolyte with a nitrate‐driven solvation structure, and the nitrate‐derived N‐rich inorganic interface shows excellent performance in stabilizing the LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (NCM811) cathode interface and modulating the lithium deposition morphology on the anode. The results show that the Li|| NCM811 cell has exceptional long‐cycle stability of >80% capacity retention after 800 cycles at 4.3 V, 1 C. A more prominent capacity retention rate of 93.3% after 200 cycles can be reached with the high voltage of 4.5 V. While being compatible with the phosphate‐based electrolyte with good flame retardancy and the good electrochemical stability of Ni‐rich lithium metal battery (LMBs) systems, the present work expands the construction of anion‐rich solvation structures, which is expected to promote the development of the high‐performance LMBs with safety.