where σ is ionic conductivity (S/cm), R is total resistance (ohm), l is the
thickness of the sample (cm) and A is the area of the sample (cm2).
Electrochemical performance tests were carried out using an automatic galvanostatic
charge–discharge unit, WBCS3000 battery cycler, between 0 and 2.0 V at room temperature. The
experiments were carried out at 0.06 mA/cm2 current density.