Figure 11 .
AC impedance spectra of the SnO2/GNS nanocomposite electrode (a) before cycling, (b) after 5 cycles, and (c) after 100 cycles. The inset shows the equivalent circuit model: Rs – resistance of the electrolyte; Rct – charge transfer resistance; Zw – Warburg resistance; CPE – constant phase element.
Wang et al. Nanoscale Research Letters 2012 7:215 doi:10.1186/1556-276X-7-215