Engineering 3D hybrid electrode composed of ceria nanoparticles embedded in nickel oxides for high-performance supercapacitors

We report on the development of a facile and rational template-free method to engineer three-dimensional (3D) intact hybrid electrodes for high-performance pseudocapacitance supercapacitor (SC) applications. A unique half-cell scheme with ceria nanoparticles embedded in nickel oxide (i.e., NiO@CeO2) electrode is developed via an in situ solvothermal and annealed methodology. Owing to the hierarchical structure nature of NiO@CeO2 and the conductive 3D foamed nickel (FN) substrate characteristics, the resultant of 3D NiO@CeO2 hybrid electrodes exhibits excellent capacity performance (1250.44Fg(-1) at 1Ag(-1)) with a maximal energy density of 203Whkg(-1) at 2.21kWkg(-1). The enhanced specific capacitance is attributed to the coexisting oxygen vacancies and the nanoscale effect in the developed 3D NiO@CeO2 architecture, facilitating the charge transfer rate between electrodes and electrolyte interfaces with elaborating high electrical conductivity. Moreover, in the 2000 cycles evaluation process, a high-power specific capacitance is demonstrated in the first few cycles of charge and discharge processes with 88% capacitive retention rate, illustrating that the developed electrodes could be considered a primary promising candidate for sustainable energy storage and conversion supercapacitor applications.