Lithium nitrate regulated carbonate electrolytes for practical Li-metal batteries: Mechanisms, principles and strategies

Li-metal batteries (LMBs) regain research prominence owing to the ever-increasing high-energy require-ments. Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Li-metal anode (LMA), leading to the formation of unstable solid electrolyte interphase (SEI) and the breed of Li dendrites/dead Li. Significantly, lithium nitrate (LiNO3), an excellent film-forming additive, proves crucial to construct a robust Li3N/Li2O/LixNOy-rich SEI after combining with ether-based electrolytes. Thus, the given challenge leads to natural ideas which suggest the incorporation of LiNO3 into commer-cial carbonate for practical LMBs. Regrettably, LiNO3 demonstrates limited solubility (-800 ppm) in com-mercial carbonate electrolytes. Thence, developing stable SEI and dendrite-free LMA with the incorporation of LiNO3 into carbonate electrolytes is an efficacious strategy to realize robust LMBs via a scalable and cost-effective route. Therefore, this review unravels the grievances between LMA, LiNO3 and carbonate electrolytes, and enables a comprehensive analysis of LMA stabilizing mechanism with LiNO3, dissolution principle of LiNO3 in carbonate electrolytes, and LiNO3 introduction strategies. This review converges attention on a point that the LiNO3-introduction into commercial carbonate elec-trolytes is an imperious choice to realize practical LMBs with commercial 4 V layered cathode.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Li-metal batteries (LMBs) are attracting research attention again due to their high-energy requirements. Commercial carbonate electrolytes have unfavorable reactions with the Li-metal anode, leading to the formation of unstable solid electrolyte interphase (SEI) and Li dendrites. However, the incorporation of lithium nitrate (LiNO3) into commercial carbonate electrolytes can successfully stabilize the SEI and enable dendrite-free Li-metal anode, making LMBs practical.