Recent advances in the development of two-dimensional transition-metal chalcogenides (2D TMCs) have opened up new avenues for supercapacitor applications. However, they still suffer from limited specific capacitance and poor rate capability due to their poor interfacial properties and simple geometry. Here, we propose a facile strategy for the synthesis of yolk-shell NiGa2S4 microspheres comprising crumpled nanosheets supported on nickel foam. The robust structure not only highly facilitates the electron and charge transportation but also efficiently alleviates the volume expansion during redox reactions, contributing to excellent electrochemical behaviors in terms of specific capacitance and rate capability. Significantly, an asymmetric supercapacitor based on the prepared NiGa2S4 as the positive electrode and N,S-codoped graphene/Fe2O3 (N,S-G/Fe2O3) as the negative electrode delivers a high energy density of 43.6 W h kg-1 at a power density of 961 W kg-1 and retains an energy density of 22.2 W h kg-1 even at 15 974 W kg-1. These impressive results may provide a new perspective to develop high energy and power density storage systems for practical applications.
Bibliographical noteFunding Information:
This work was supported by the Global Frontier R&D Program (2013M3A6B1078874) on Center for Hybrid Interface Materials (HIM) funded by the Ministry of Science, ICT & Future Planning, the Priority Research Centers Program (2009-0093823), and the Korean Government (MSIP) (No. 2015R1A5A1037668) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST), and ICT & Future Planning.
© 2017 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)