Balanced mesoporous nickle cobaltite-graphene and doped carbon electrodes for high-performance asymmetric supercapacitor

Mesoporous rod-like nickel cobaltite decorated on graphene has been fabricated by a facile hydrothermal method. Due to multiple redox reactions on nickel cobaltite, a high capacitance of 845 F g (1) can be obtained. In order to get high energy and power densities, an asymmetric supercapacitor has been assembled by using mesoporous nickel cobaltite-graphene nanocomposite as the positive electrode and doped carbon as the negative electrode. Benefitting from the balanced capacity on positive and negative electrode, the fabricated asymmetric supercapacitor exhibit a remarkable energy density of 52.2 Wh kg (1) and excellent cycling life with 97.3% capacitance retention ratio after 10,000 cycles. The outstanding electrochemical performance can be attributed to the synergetic contribution of these two electrodes, which gives a promising way for designing high performance energy storage device. (C) 2017 Elsevier B.V. All rights reserved.