Ice-templated Self-assembly of VOPO4-Graphene Nanocomposites for Vertically Porous 3D Supercapacitor Electrodes

Title
Ice-templated Self-assembly of VOPO4-Graphene Nanocomposites for Vertically Porous 3D Supercapacitor Electrodes
Authors
이광훈이영우이승우하정숙이상수손정곤
Keywords
supercapacitor; graphene; 3D porous
Issue Date
2015-09
Publisher
Scientific Reports
Citation
VOL 5, 13696
Abstract
A simple ice-templated self-assembly process is used to prepare a three-dimensional (3D) and vertically porous nanocomposite of layered vanadium phosphates (VOPO4) and graphene nanosheets with high surface area and high electrical conductivity. The resulting 3D VOPO4–graphene nanocomposite has a much higher capacitance of 527.9 F g−1 at a current density of 0.5 A g−1, compared with ~247 F g−1 of simple 3D VOPO4, with solid cycling stability. The enhanced pseudocapacitive behavior mainly originates from vertically porous structures from directionally grown ice crystals and simultaneously inducing radial segregation and forming inter-stacked structures of VOPO4–graphene nanosheets. This VOPO4–graphene nanocomposite electrode exhibits high surface area, vertically porous structure to the separator, structural stability from interstacked structure and high electrical conductivity, which would provide the short diffusion paths of electrolyte ions and fast transportation of charges within the conductive frameworks. In addition, an asymmetric supercapacitor (ASC) is fabricated by using vertically porous VOPO4–graphene as the positive electrode and vertically porous 3D graphene as the negative electrode; it exhibits a wide cell voltage of 1.6 V and a largely enhanced energy density of 108 Wh kg−1
URI
http://pubs.kist.re.kr/handle/201004/50233
ISSN
20452322
Appears in Collections:
KIST Publication > Article
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