The electrochemical behavior of graphite electrodes cycled galvanostat
ically versus Li metal in electrolyte solutions containing LiPF6, LiC(
SO2CF3)(2), and LiN(SO2C2F5)(2) in ethyl and methyl alkyl carbonates w
as studied. The solvents include ethyl methyl, ethyl propyl, methyl pr
opyl, isopropyl methyl, and isopropyl ethyl carbonates. The use of asy
mmetric, aliphatic alkyl methyl carbonates is shown to be essential to
achieve both high capacity and long cycle life with graphite electrod
es in Li-ion batteries.