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Lithium metal anode is strongly regarded as a promising candidate in next-generation energy storage devices. Lithium nitrate (LiNO3) is widely applied as an effective additive in ether electrolyte to increase the interfacial stability in batteries with lithium metal anodes, however, LiNO3 is rarely involved in high-voltage-window carbonate electrolyte for its poor solubility. Herein, we realize the dissolution of LiNO3 in carbonate electrolyte through an effective solvation regulation strategy. LiNO3 can be directly dissolved in ethylene carbonate/diethyl carbonate electrolyte by adding trace amounts of copper fluoride as a dissolution promoter. The LiNO3 can therefore protect Li metal anode in a working high-voltage Li metal battery. When pairing LiNi0.80Co0.15Al0.05O2 cathode with Li metal anode, an extraordinary capacity retention of 53% is achieved after 300 cycles (13% after 200 cycles for LiNO3-free electrolyte) and a very high average Coulombic efficiency above 99.5% is achieved at 0.5 C. This work presents a deep understanding on the solvation chemistry of LiNO3-containing carbonate electrolyte and demonstrates a compatible system for Li metal anode working in the corrosive carbonate electrolytes towards safe high-voltage batteries.
PMID: 30094909 [PubMed - as supplied by publisher]