Investigation of layered LiNi1/3Co1/3Mn1/3O2 cathode of lithium ion battery by electrochemical impedance spectroscopy

► We obtained exhaustive electrochemical properties of LiNi1/3Co1/3Mn1/3O2 by EIS. ► We first observed three semicircles via a three-electrode glass cell by EIS. ► The drastic change of electronic conductivity of LiNi1/3Co1/3Mn1/3O2 was observed. ► We proved the presence of an insulator to metal transition in LiNi1/3Co1/3Mn1/3O2. ► Kinetic parameters were calculated in 1 mol L−1 LiPF6-EC: DEC: DMC.