Self-assembly of mesoporous nanotubes assembled from interwoven ultrathin birnessite-type MnO2 nanosheets for asymmetric supercapacitors.
Porous nanotubes comprised of MnO2 nanosheets were fabricated with a one-pot hydrothermal method using polycarbonate membrane as the template. The diameter and thickness of nanotubes can be controlled by choice of the membrane pore size and the chemistry. The porous MnO2 nanotubes were used as a supercapacitor electrode. The specific capacitance in a three-electrode system was 365 F g(-1) at a current density of 0.25 A g(-1) with capacitance retention of 90.4% after 3000 cycles. An asymmetric supercapacitor with porous MnO2 nanotubes as the positive electrode and activated graphene as the negative electrode yielded an energy density of 22.5 Wh kg(-1) and a maximum power density of 146.2 kW kg(-1); these values exceeded those reported for other MnO2 nanostructures. The supercapacitor performance was correlated with the hierarchical structure of the porous MnO2 nanotubes.
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, P.R. China.
Ming
M
Huang
1] College of Materials Science and Engineering, Chongqing University, Chongqing 400044, P.R. China [2] National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044, P.R. China.
Yuxin
Y
Zhang
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, P.R. China.
Fei
F
Li
Institute of Chemical and Engineering Sciences, A*STAR, 1 Pesek Road, Jurong Island 627833, Singapore.
Lili
L
Zhang
Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin, One University Station C2200, Austin, Texas 78712, United States.
Rodney S
RS
Ruoff
National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044, P.R. China.
Zhiyu
Z
Wen
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, P.R. China.
Qing
Q
Liu