Integrated Electrode of PPy/Ni(OH)2 Composite on Nickel Foam with Enhanced Electrochemical Performance for Hybrid supercapacitors

In this work, a novel three-dimensional integrated electrode of Ni(OH)(2) nanosheets anchored by polypyrrole (PPy) nanosheets on nickel foam (NF) (assigned as PPy/Ni(OH)(2)/NF) was fabricated via a facial two-step approach. Compared to Ni(OH)(2)/NF electrode, the electrochemical performance of PPy/Ni(OH)(2)/NF electrode could be enhanced due to the superior conductivity of PPy and synergistic effect of PPy and Ni(OH)(2). The PPy/Ni(OH)(2)/NF shows high specific capacity (869.6 C g(-1) at a current density of 4 A g(-1)) and better rate performance. Moreover, the existence of PPy can efficiently withstand the mechanical stress and volume expansion during long-term charge-discharge process. The PPy/Ni(OH)(2)/NF integrated electrode possesses 80.7% retention of specific capacity after 5000 cycles. The fabricated hybrid supercapacitor (HSC) shows the highest energy density of 42 Wh kg(-1) at 350 W kg(-1) and the highest power density of 11200 W kg(-1) at 29 Wh kg(-1) and the superior cycling performance (81% retention after 5000 cycles). The design of a three-dimensional binder-free electrode demonstrates a novel material for energy storage and provides potential in practical application. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.