Rational assembly and hetero-growth of hybrid structures consisting of multiple components with distinctive features are a promising and challenging strategy to develop materials for energy storage applications. Herein, we propose a supercapacitor electrode comprising a three-dimensional self-supported hierarchical MnCo-layered double hydroxides@Ni(OH)2 [MnCo-LDH@Ni(OH)2] core-shell heterostructure on conductive nickel foam. The resultant MnCo-LDH@Ni(OH)2 structure exhibited a high specific capacitance of 2320 F g-1 at a current density of 3 A g-1, and a capacitance of 1308 F g-1 was maintained at a high current density of 30 A g-1 with a superior long cycle lifetime. Moreover, an asymmetric supercapacitor was successfully assembled using MnCo-LDH@Ni(OH)2 as the positive electrode and activated carbon (AC) as the negative electrode. The optimized MnCo-LDH@Ni(OH)2//AC device with a voltage of 1.5 V delivered a maximum energy density of 47.9 W h kg-1 at a power density of 750.7 W kg-1. The energy density remained at 9.8 W h kg-1 at a power density of 5020.5 W kg-1 with excellent cycle stability.
Bibliographical noteFunding Information:
This work was partially supported by the Priority Research Centers Program (2009-0093823), the Korean Government (MSIP) (No. 2015R1A5A1037668) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST), the Korea Research Fellowship Program (2015-11-1063) funded by the Ministry of Science, ICT and Future Planning through the National Research Foundation of Korea, and the Yonsei University Future-leading Research Initiative.
© The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)