Where the ohmic and charge transfer resistance are represented as Rs and Rct respectively. Also, ɷ -1/2 was measured in the low-frequency region denotes the reciprocal square root of the angular frequency. The relation between Z՛ and ɷ -1/2 is observed at low-frequency regions as shown in Fig. for all the electrodes. In Table , the diffusion coefficient of Li-ion derived from equations