One-pot synthesis of NiO-MnCo2O4 heterostructure hollow spheres via template-free solvothermal method for high-performance supercapacitors

Abstract

Supercapacitors employ transitional metal oxides as pseudocapacitive materials have drawn great attention owing to their prominent energy storage performances, but most of them are concentrate on simplex metal oxides. In this work, we reported a novel electrode material for supercapacitors composed of NiO-MnCo2O4 heterostructure hollow spheres via a facile and one-pot route. The resulting hybrid electrode material demonstrates a high specific capacity of 660 C g−1 at 1 A g−1. An assembled hybrid supercapacitor based on this unique heterostructure hollow spheres as positive electrode and nitrogen doped hierarchically porous carbon as negative electrode indicates a favorable energy density of 40 Wh kg−1 at 750 W kg−1 and long cycling lifespan of nearly 90% capacity retention rate after 5000 cycles. This work not only produces a competitive electrode material for energy storage devices but also offers a feasible strategy for producing complex transitional metal oxides materials with high capacitive performance.