Figure 5.

(a) Results of EIS measurements of the SiO₂-rGO@PPy and SiO₂-rGO electrodes before and after 250 cycles at a current density of 100 mA g⁻¹, as well as the corresponding equivalent circuits. (b) The relationship between the real impedance (Z′) and reciprocal square root of the frequencies ($\omega$^−0.5) in the low-frequency region before and after cycle testing of the SiO₂-rGO@PPy and SiO₂-rGO electrodes.