A high-performance asymmetric supercapacitors based on hydrogen bonding nanoflower-like polypyrrole and NiCo(OH)2 electrode materials

Abstract

NickelCobalt dihydroxide (NiCo(OH)2) is a promising electrode materials in supercapacitors (SCs), yet how to improve its cycling stability without losing capacitance is still a challenge. Herein, we report an innovative and facile solution approach to fabricate hydrogen bond nanoflower-like Polypyrrole and NiCo(OH)2 (PPy@NiCo(OH)2) electrode. In which a three-hydrogen bond system is used to combine modified-NiCo(OH)2 and PPy through the hydrogen bonding between the N and H. Research result shows that the PPy@NiCo(OH)2 possesses an extraordinary specific capacitance of 1469.25 F g−1 at current density of 1 A g−1 and excellent cycling stability about 95.2% capacity retention after 10,000 cycles at current density of 30 A g−1, which is superior than pure NiCo(OH)2. An asymmetric all solid-state supercapacitor, employed active carbon (AC) and PPy@NiCo(OH)2 as negative and positive electrodes, respectively, was also assembled and tested. Which achieves an ultra-high specific capacitance of 307.14 F g−1 current density of 1 A g−1, as well as excellent cycling stability of capacity retention of 93% after 5000 cycles. This strategy may shed light on designing of organic-inorganic combined new electrode materials for supercapacitors and other electrochemical devices.