文献类型：期刊文献

英文题名：High-power and high-energy asymmetric supercapacitors based on Li+-intercalation into a T-Nb2O5/graphene pseudocapacitive electrode

作者：Kong, Lingping[1];Zhang, Chuanfang[1];Zhang, Songmin[1];Wang, Jitong[1];Cai, Rong[2];Lv, Chunxiang[2];Qiao, Wenming[1];Ling, Licheng[1];Long, Donghui[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Chinese Acad Sci, Inst Coal Chem, Natl Engn Lab Carbon Fiber Technol, Taiyuan 030001, Peoples R China

年份：2014

卷号：2

期号：42

起止页码：17962

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY A

收录：;EI(收录号：20144200104179);WOS:【SCI-EXPANDED(收录号:WOS:000343961300033)】；

基金：This work was partly supported by MOST (2014CB239702) and the National Science Foundation of China (no. 51302083, no. 51172071, no.51272077), and Fundamental Research Funds for the Central Universities and Shanghai Pujiang Program.

语种：英文

外文关键词：Nanocrystals - Supercapacitor - Electrochemical electrodes - Niobium oxide - Electric discharges

摘要：The intercalation pseudocapacitance which leads to the extraordinary charge storage properties has been confirmed as an intrinsic capacitive property of orthorhombic Nb2O5 (T-Nb2O5) nanocrystals. However, the poor electronic conductivity of T-Nb2O5 nanocrystals may limit their electrochemical utilization and high-rate performance especially for thick electrodes with high mass loadings. To address this issue, we herein reported a hydrothermal-heat treatment method to anchor T-Nb2O5 nanocrystals on conductive graphene sheets, which form a layer-by-layer integrated electrode with much shortened ion transport paths and results in excellent electrochemical capacitive properties, including high capacitance (626 C g(-1)), excellent rate handling and cyclic stability. Furthermore, asymmetric supercapacitors were constructed by using the high-rate response T-Nb2O5/graphene nanocomposite and mesoporous carbon as the negative and positive electrode, respectively. The asymmetric supercapacitor could deliver a high energy density of 16 W h kg(-1) at an unprecedented power density of 45 kW kg(-1) (discharge time of 1.2 s). The outstanding power properties of the supercapacitors are mainly attributed to the improved high-rate Li-insertion/extraction capability of the T-Nb2O5/graphene electrode and appropriate pairing of the mesoporous carbon electrode.