Suppression of Self-Discharge by a LiPF6/Methyl Difluoroacetate Electrolyte in Li/CuCl2 Batteries

Methyl difluoroacetate (MFA) was used as an electrolyte solvent in Li/CuCl2 batteries, and the LiPF6/MFA electrolyte was effective for the suppression of the self-discharge of Li/CuCl2 batteries. The dependence of self-discharge behavior on LiPF6 concentration (1.0, 1.4, 1.8, 2.2, and 2.7 mol dm(-3)) in MFA-based electrolytes was investigated. The lowest self-discharge was observed for a 2.2 mol dm(-3) LiPF6/MFA electrolyte under the described conditions, and an initial discharge capacity of 395 mAh g(-1) was maintained after 678 h (4 weeks) of rest. The cycling performance of the LiPF6/MFA electrolytes was evaluated, and the discharge capacity for the 2.2 mol dm(-3) LiPF6/MFA electrolyte was found to be maintained at 183 mAh g(-1) (10th cycle). Therefore, 2.2 mol dm(-3) LiPF6/MFA electrolyte is confirmed to be effective for the suppression of the self-discharge of Li/CuCl2 batteries. (C) 2015 The Electrochemical Society. All rights reserved.