Factors affecting the performance of supercapacitors assembled with polypyrrole/multi-walled carbon nanotube composite electrodes

In this study, polypyrrole/multi-walled carbon nanotube (PPy/MWCNT) composites were synthesized in water, dichloromethane and n-hexane solvents and the conducting composite materials were tested as symmetric 2-electrode electrochemical capacitors. The synthesis method, electrolyte type, and binder compositions had profound effects on the overall performance of the cells. The microscopic structure of the composites and hydrophilicity of the electrode materials also influenced the capacitor behavior. The cells assembled with the PPy/MWCNT composites had a high specific capacitance (165 F g−1) and excellent cycleability for up to 1000 cycles in 1.0 M KCl electrolyte. The composite electrodes showed no capacitance loss due to the increase of internal resistance of the materials and thus, they exhibited ideal supercapacitor characteristics.