context: The cathodes were prepared by mixing 80 wt% active materials, 10 wt% acetylene black and 10 wt% polyvinylidene fluoride (PVDF) binder with N-methyl-2-pyrrolidone (NMP) as the solvent. The mixture was coated on aluminum foil, pressed at 20 MPa, and dried at 120 °C in air for 2 h. The 2025 coin-type cells, consisting of the as-prepared cathode, Li metal as the anode and Celgard 2325 as the separator, were assembled in an argon-filled glove box. The electrolyte was 1 M LiPF6 dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio 3:7). All cells were cycled between 2.0 and 4.8 V (versus Li/Li+) at a current density of 20 mA g−1 at room temperature on Land CT 2001A battery testers unless otherwise defined. The electrochemical impedance spectroscopy (EIS) measurements were performed from 100 kHz to 10 mHz with an amplitude of 10 mV using a multichannel potentiostat (PARSTAT MC).