High-loading Co-doped NiO nanosheets on carbon-welded carbon nanotube framework enabling rapid charge kinetic for enhanced supercapacitor performance

Developing high power and energy supercapacitors (SCs) is a long-pursued goal for the application in transportation and energy storage station. Herein, a rationally-designed Co-doped nickel oxide nanosheets@carbon-welded carbon nanotube foam (Co-doped NiO@WCNTF) as freestanding electrode is successfully prepared for high power and energy SCs. The WCNTF framework with high specific surface area provides three dimensional highly conductive network for fast charge transport and ensures high loading of active materials (9.2 mg/cm 2 ). Moreover, porous Co-doped NiO nanosheets uniformly anchored on the WCNTF framework enable rapid charge kinetics due to the high intrinsic conductivity of Co-doped NiO nanosheets and their good contact with conductive WCNTF substrate. As a result, the unique integrated electrode with 3D architecture exhibits an ultrahigh specific capacitance of 11.45 F/cm 2 at 5 mA/cm 2 , outstanding rate capability (11.45 F/cm 2 at 5 mA/cm 2 and a capacitance retention of 86.2% at 30 mA/cm 2 ) and good cycling stability, suggesting great potential for high performance supercapacitor .