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

Abstract

Pseudocapacitive\nmaterials are critical to the development of supercapacitors but usually\nsuffer from poor conductivity and bad cycling property. Here, we describe\nthe production of novel graphene oxide nanofibers (GONFs) via a partial\noxidization and exfoliation method and concurrently report that highly\ncrystallized Ni­(OH)₂ nanoplates uniformly grow on reduced\nGONFs’ outer graphene nanosheets through the hydrothermal method.\nBecause of their unique structure with high electric conductivity,\nthe rGONF/Ni­(OH)₂ composite exhibits superior specific\ncapacitance (SC), favorable rate capability and enhanced cycling stability\nrelative 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\nafter 2000 cycles, and as-fabricated rGONF/Ni­(OH)₂//active\ncarbon asymmetric supercapacitor (ASC) exhibits a remarkable energy\ndensity 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\n0–1.7 V. Therefore,\nthis study shows that rGONFs offers an exciting opportunity as substrate\nmaterials for supercapacior applications and opens up a new pathway\nfor design and manufacture of novel supercapacitor electrode materials.