Supercapacitors Based on Reduced Graphene Oxide Nanofibers Supported Ni(OH)₂ Nanoplates with Enhanced Electrochemical Performance

Abstract

Pseudocapacitive materials are critical to the development of supercapacitors but usually suffer from poor conductivity and bad cycling property. Here, we describe the production of novel graphene oxide nanofibers (GONFs) via a partial oxidization and exfoliation method and concurrently report that highly crystallized Ni(OH)2 nanoplates uniformly grow on reduced GONFs' outer graphene nanosheets through the hydrothermal method. Because of their unique structure with high electric conductivity, the rGONF/Ni(OH)2 composite exhibits superior specific capacitance (SC), favorable rate capability and enhanced cycling stability relative to other composites or hybrids, e.g., 1433 F g(-1) at 5 mV s(-1) scan rate, 986 F g(-1) at 40 mV s(-1), and 90.5% capacitance retention after 2000 cycles, and as-fabricated rGONF/Ni(OH)2//active carbon asymmetric supercapacitor (ASC) exhibits a remarkable energy density and a 85.3% high retention (44.1 Wh kg(-1) at 467 W kg(-1) and 37.6 Wh kg(-1) at 3185 W kg(-1)) with a wide potential window of 0-1.7 V. Therefore, this study shows that rGONFs offers an exciting opportunity as substrate materials for supercapacior applications and opens up a new pathway for design and manufacture of novel supercapacitor electrode materials.