Figure 6

CV and charge–discharge curves of the composites. (A) CV curves of the as-prepared samples in 0.1 M HClO₄solution at 50 mV s⁻¹, curves a to d: MnO₂/PANI fabricated in 1, 0.05, and 0.02 M HClO₄, and 0.1 M NaOH, respectively. Curve e: 500°C-treated MnO₂/PANI fabricated in 0.02 M HClO₄. (B) Charge–discharge curves of the MnO₂/PANI composite in 0.1 M HClO₄ solution at different current densities. (C) First 20 cycles of charge–discharge curves for the MnO₂/PANI composite at the current density of 1 mA cm⁻² (D) Dependence of capacitance of the MnO₂/PANI composite on the charge–discharge cycles at the current density of 1 mA cm⁻².