Physicochemical and electrochemical properties of imidazolium ionic liquids: Cycling performance of low cost lithium ion batteries with LiFePO_4 cathode

摘要

This manuscript reports investigation conducted on room temperature ionic liquids (RTILs) C_1C_nImNTf_2/n=4, 6 in order to use it as electrolyte solvent in lithium ion battery. The ionic conductivity, viscosity, ion self-diffusion coefficients, and electrochemical stability in C_lC_nImNTf_2 are presented. A solution of C_1C_nImNTf_2/n=4, 6 containing 1.6 mol.L~(-1) of LiNTf_2 has been used as the electrolyte in a Li-ion battery with graphite and LiFePO_4 as respectively negative and positive active materials. [Li][C_1C_6Im][NTf_2] shows the best cycling performance: a capacity up to 120 mAh.g~(-1) at C/10 rate at 25°C.