biostudies-literatureLiu SVehicle Technologies OfficeDepartment of EnergyU.S. Department of Energye202210522https://www.ebi.ac.uk/biostudies/studies/S-EPMC9826201biostudies-literatureUnknown61(43)The instability of carbonate electrolyte with metallic Li greatly limits its application in high-voltage Li metal batteries. Here, a "salt-in-salt" strategy is applied to boost the LiNO₃ solubility in the carbonate electrolyte with Mg(TFSI)₂ carrier, which enables the inorganic-rich solid electrolyte interphase (SEI) for excellent Li metal anode performance and also maintains the cathode stability. In the designed electrolyte, both NO₃ ^- and PF₆ ^- anions participate in the Li⁺ -solvent complexes, thus promoting the formation of inorganic-rich SEI. Our designed electrolyte has achieved a superior Li CE of 99.7 %, enabling the high-loading NCM811||Li (4.5 mAh cm^-2 ) full cell with N/P ratio of 1.92 to achieve 84.6 % capacity retention after 200 cycles. The enhancement of LiNO₃ solubility by divalent salts is universal, which will also inspire the electrolyte design for other metal batteries.Angewandte Chemie (International ed. in English)Salt-in-Salt Reinforced Carbonate Electrolyte for Li Metal Batteries.PMC9826201No. DE-AC05-76RL01830Zhang WDeng TXia JZhang JNan BWang CLiu SWan HRao JHou SXu JfalseSalt-in-Salt Reinforced Carbonate Electrolyte for Li Metal Batteries.The instability of carbonate electrolyte with metallic Li greatly limits its application in high-voltage Li metal batteries. Here, a "salt-in-salt" strategy is applied to boost the LiNO₃ solubility in the carbonate electrolyte with Mg(TFSI)₂ carrier, which enables the inorganic-rich solid electrolyte interphase (SEI) for excellent Li metal anode performance and also maintains the cathode stability. In the designed electrolyte, both NO₃ ^- and PF₆ ^- anions participate in the Li⁺ -solvent complexes, thus promoting the formation of inorganic-rich SEI. Our designed electrolyte has achieved a superior Li CE of 99.7 %, enabling the high-loading NCM811||Li (4.5 mAh cm^-2 ) full cell with N/P ratio of 1.92 to achieve 84.6 % capacity retention after 200 cycles. The enhancement of LiNO₃ solubility by divalent salts is universal, which will also inspire the electrolyte design for other metal batteries.2022-01-01T00:00:00Z2022 Oct2026-03-27T15:40:48.214Z2025-04-05T10:26:57.508ZS-EPMC98262013604084010.1002/anie.202210522