Refinement of structural characteristics and supercapacitor performance of MnO2 nanosheets via CTAB-assisted electrodeposition

MnO2 stands out as a highly promising material for electrochemical capacitors due to its impressive theoretical capacitance, cost-effectiveness, eco-friendliness, and abundant natural availability. Yet, its inherent low conductivity and structural fragility result in restricted specific capacitance and a shortened cycle life, posing a notable obstacle to its advancement. Through the introduction of CTAB (cetyltrimethylammonium bromide), we successfully tailored the surface morphology of the electrode material, yielding a robust and highly conductive layered MnO2 electrode material. The MnO2/CTAB composite synthesized through a simple electrodeposition method exhibits outstanding performance, achieving a specific capacitance of 665 ​F ​g−1 ​at 1 ​A ​g−1. Even after 30,000 cycles, it maintains 92.13% capacitance. The performance improvement is primarily attributed to increased conductivity, and additional electrochemically active sites. Additionally, the assembled MnO2/CTAB//AC capacitor (ACs) achieves a specific capacitance of 70.06 ​F ​g−1 ​at 1 ​A ​g−1, operating at a voltage of 1.8 ​V. At a power density of 563.36 ​W ​kg-1, it reaches an energy density of 35.21 ​Wh kg-1. This work provides an effective approach for high-performance electrode of supercapacitor.