Achieving Practical High‐Energy‐Density Lithium‐Metal Batteries by a Dual‐Anion Regulated Electrolyte

Lithium‐metal batteries (LMBs) using lithium‐metal anodes and high‐voltage cathodes have been deemed as one of the most promising high‐energy‐density battery technology. However, its practical application is largely hindered by the notorious dendrite growth of lithium‐metal anodes, the fast structure degradation of the cathode, and insufficient electrode–electrolyte interphase kinetics. Here, a dual‐anion regulated electrolyte is developed for LMBs using lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and lithium difluoro(bisoxalato)phosphate (LiDFBOP) as anion regulators. The incorporation of TFSI− in the solvation sheath reduces the desolvation energy of Li+, and DFBOP− promotes the formation of highly ion‐conductive and sustainable inorganic‐rich interphases on the electrodes. Significantly enhanced performance is demonstrated on Li||LiNi0.83Co0.11Mn0.06O2 pouch cells, with 84.6% capacity retention after 150 cycles in 6.0 Ah pouch cells and an ultrahigh rate capability up to 5 C in 2.0 Ah pouch cells. Furthermore, a pouch cell with an ultralarge capacity of 39.0 Ah is fabricated and achieves an ultrahigh energy density of 521.3 Wh kg−1. The findings provide a facile electrolyte design strategy for promoting the practical utilization of high‐energy‐density LMBs. A dual‐anion regulated electrolyte is developed for practical lithium‐metal batteries (LMBs). The electrolyte enables fast interfacial kinetics and forms robust inorganic‐rich and highly ion‐conductive electrode–electrolyte interphase layers on the surfaces of the electrodes, demonstrates exceptional performance in Li||NCM83 pouch cells, and realizes LMBs with an ultrahigh capacity of 39.0 Ah and ultrahigh energy density of 521 Wh kg−1.