Assembly of polypyrrole nanotube@MnO2 composites with an improved electrochemical capacitance

- PPy nanotube@MnO2 composites have been prepared.
- The thickness of MnO2 coating can be tuned by the concentration of KMnO4.
- Synergistic effect between PPy and MnO2 generates better capacitance performance.
- The composites exhibit high specific capacitance and good cycle stability.