title: High energy density asymmetric supercapacitors with a nickel oxide nanoflake cathode and a 3D reduced graphene oxide anode.
abstract: Here we demonstrate a high energy density asymmetric supercapacitor with nickel oxide nanoflake arrays as the cathode and reduced graphene oxide as the anode. Nickel oxide nanoflake arrays were synthesized on a flexible carbon cloth substrate using a seed-mediated hydrothermal method. The reduced graphene oxide sheets were deposited on three-dimensional (3D) nickel foam by hydrothermal treatment of nickel foam in graphene oxide solution. The nanostructured electrodes provide a large effective surface area. The asymmetric supercapacitor device operates with a voltage of 1.7 V and achieved a remarkable areal capacitance of 248 mF cm(-2) (specific capacitance of 50 F g(-1)) at a charge/discharge current density of 1 mA cm(-2) and a maximum energy density of 39.9 W h kg(-1) (based on the total mass of active materials of 5.0 mg). Furthermore, the device showed an excellent charge/discharge cycling performance in 1.0 M KOH electrolyte at a current density of 5 mA cm(-2), with a capacitance retention of 95% after 3000 cycles.
authors.affiliation: Department of Chemistry, Northeastern University, Shenyang, 110819, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Luan
authors.forename: Gongming
authors.initials: G
authors.lastname: Wang
authors.forename: Yichuan
authors.initials: Y
authors.lastname: Ling
authors.forename: Xihong
authors.initials: X
authors.lastname: Lu
authors.forename: Hanyu
authors.initials: H
authors.lastname: Wang
authors.forename: Yexiang
authors.initials: Y
authors.lastname: Tong
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Liu
authors.forename: Yat
authors.initials: Y
authors.lastname: Li
mesh_terms: D025802:Electric Capacitance; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry
chemical_list: D010087:Oxides; D006108:Graphite; D009532:Nickel; C028007:nickel monoxide