Lee, Kwang Hoon Lee, Young-Woo Lee, Seung Woo Ha, Jeong Sook Lee, Sang-Soo Son, Jeong Gon 2024-01-20T06:04:07Z 2024-01-20T06:04:07Z 2021-09-04 2015-09-03 2045-2322 https://pubs.kist.re.kr/handle/201004/125032 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 similar to 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). English NATURE PUBLISHING GROUP HIGH-ENERGY DENSITY HIGH-PERFORMANCE ELECTROCHEMICAL PROPERTIES FUNCTIONALIZED GRAPHENE ULTRATHIN NANOSHEETS OXIDE SHEETS Ice-templated Self-assembly of VOPO4-Graphene Nanocomposites for Vertically Porous 3D Supercapacitor Electrodes Article 10.1038/srep13696 1 SCIENTIFIC REPORTS, v.5 SCIENTIFIC REPORTS 5 scie scopus 000360535600001 2-s2.0-84940848264 Multidisciplinary Sciences Science & Technology - Other Topics Article HIGH-ENERGY DENSITY HIGH-PERFORMANCE ELECTROCHEMICAL PROPERTIES FUNCTIONALIZED GRAPHENE ULTRATHIN NANOSHEETS OXIDE SHEETS supercapacitor graphene 3D porous