R. Petibon, C. Aiken, Lin Ma
Feb 1, 2015
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Influential Citations
82
Citations
Quality indicators
Journal
Electrochimica Acta
Abstract
Abstract The use of highly concentrated lithium bis(fluorosulfonyl)imide (LiFSi) electrolyte in ethyl acetate (EA) is reported here. Li[Ni 0.33 Mn 0.33 Co 0.33 ]O 2 /graphite (NMC(111)/graphite) and Li[Ni 0.42 Mn 0.42 Co 0.16 ]O 2 /graphite (NMC(442)/graphite) pouch cells filled with a 3:32:65 (molar ratio) of LiPF 6 :LiFSi:EA electrolyte, were successfully cycled between 2.8–4.2 V and 2.8–4.4 V, respectively at 40 °C over a period of several weeks without dramatic capacity loss. Cells filled with the highly concentrated LiFSi:EA electrolyte demonstrated surprisingly low impedance compared to a conventional electrolyte composed of organic carbonates after 400–800 h of cycling at 40 °C. LiFSi was the most effective salt in reducing the amount of ethyl acetate consumed at the negative electrode during the first charge compared to LiPF 6 and lithium bis(trifluoromethanesulfonyl)imide (LiTFSi) at equivalent molar ratios. The work reported here shows that highly unconventional solvents can be used in full Li-ion cells without any cyclic carbonates at all, provided high concentrations of the appropriate electrolyte salt are used.