Facile synthesis of mesoporous Ni0.3Co2.7O4 hierarchical structures for high-performance supercapacitors

Abstract

In this work, we report the facile synthesis of mesoporous nickel cobalt oxide (Ni0.3Co2.7O4) hierarchical structures with excellent supercapacitive performance. Nickel cobalt oxalate hydrate (Ni0.1Co0.9C2O4·nH2O) is first synthesized as the precursor via a facile precipitation method, followed by controlled annealing to obtain mesoporous Ni0.3Co2.7O4 hierarchical structures. The sample prepared at a relatively low annealing temperature (400 °C) possesses more abundant mesopores and higher specific surface area, and exhibits excellent supercapacitive performance in aqueous alkaline electrolytes. An exceptionally high specific capacitance of 960 and 805 F g−1 is obtained under current densities of 0.625 and 6.25 A g−1, respectively, with excellent cyclic stability. The remarkable electrochemical performance is attributed to the desirable composition and the unique hierarchical mesoporous architectures.