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 anode, fast structure degradation of cathode and insufficient electrode-electrolyte interphase kinetics. Here, a solvation structure regulation strategy 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 high ion-conductive and sustainable inorganic-rich interphases on electrodes. Significantly enhanced performance is demonstrated on Li||LiNi 0.83 Co 0.11 Mn 0.06 O 2 pouch cells, with 84.6% capacity retention after 150 cycles in 6.0 Ah pouch cells and an ultra-high rate capability up to 5 C in 2.0 Ah pouch cells. Furthermore, a pouch cell with an ultra-large capacity of 39.0 Ah is fabricated and achieves an ultra-high energy density of 521.3 Wh kg -1 . Our findings provide a facile electrolyte design strategy for promoting the practical utilization of high-energy-density LMBs. This article is protected by copyright. All rights reserved.