Hierarchical MnO2 Located on Carbon Nanotubes for Enhanced Electrochemical Performance

摘要

Herein, we assembled an asymmetric supercapacitor (ASC) with high energy and power density based on porous MnO2/nitrogen-doped carbon nanotubes (MnO2/NCNTs) in the positive electrode and chemical activated of nitrogen-doped carbon nanotubes (ANCNTs) in the negative electrode. The ANCNTs//MnO2/NCNTs ASC device operates reversibly at a high voltage of 2.0V in 1.0M Na2SO4 and exhibits a high energy density of 37.2Whkg(-1), which can be included in the top category of supercapacitors. More importantly, the supercapacitor exhibits impressive rate capability (high power density of 15100W kg(-1) at an energy density of 12.8Whkg(-1)) and exceptional cycling stability with 95.2% capacitance retention after 3000 cycles. These attractive results indicate the potential for efficient energy storage devices.