Work

Ultrahigh capacitive performance from both Co(OH)2/graphene electrode and K3Fe(CN)6 electrolyte

Year: 2013

Type: article

Abstract: Pseudocapacitance is commonly associated to the reversible redox reactions from electrode materials, but the enhancement in pseudocapacitance that only relies on electrode materials is limited. Here, we explore the possibility of enhancing pseudocapacitance through both Co(OH)₂/graphene nanosheets (GNS) electrode and K₃Fe(CN)₆ electrolyte. With a good conductivity and favoring electron transfer, GNS are hybridized with Co(OH)₂ to improve the pseudocapacitance of Co(OH)₂, including enhancing its rate capability and electrochemical stability. Adding K₃Fe(CN)₆ into KOH electrolyte further enhances the pseudocapacitance via both directly contributing pseudocapacitance to Co(OH)₂/GNS and promoting the electron gain and loss of Co ions. This novel Co(OH)₂/GNS-K₃Fe(CN)₆/KOH electrode system shows an ultrahigh specific capacitance of 7514 Fg⁻¹ at 16 Ag⁻¹ in mixed 1 M KOH and 0.08 M K₃Fe(CN)₆, more than 100% coulombic efficiency, and long-term cycling stability (the capacitance retention is 75% after 20000 continuous charge-discharge cycles in mixed 1 M KOH and 0.04 M K₃Fe(CN)₆.

Source: Scientific Reports

DOI: 10.1038/srep02986

Authors: Cuimei Zhao, Weitao Zheng, Xin Wang, Hengbin Zhang, Xiaoqiang Cui, Haoxiang Wang

Institutions: Jilin University, State Key Laboratory of High Pressure and Superhard Materials

Language: English

Topic: Supercapacitor Materials and Fabrication

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $2,690