화학공학소재연구정보센터
Electrochimica Acta, Vol.211, 217-224, 2016
A high energy density asymmetric supercapacitor from ultrathin manganese molybdate nanosheets
Manganese molybdate is highly significant to improve its energy density to meet the application requirement of hybrid vehicles and renewable energy systems. Here, we report a binder-free ultra thin manganese molybdate (MnMoO4 nH(2)O) nanosheets/nickel foam electrode for high energy density asymmetric supercapacitor by a facile one-step hydrothermal method. This binder-free electrode demonstrates a very high specific capacitance of 1271 F g(-1) at a scan rate of 5 mV s(-1). After 2000 charge/discharge cycles, 84.5% of the initial specific capacitance (945.6F g(-1)) is still maintained. Further SEM, TEM and XPS results suggest that this performance degradation can be ascribed to the mechanical expansion of MnMoO4 during the ion insertion/removal process or the dissolution of some MnMoO4 during the charge/discharge cycles. An aqueous asymmetric supercapacitor using the MnMoO4 nH2O as the cathode with an activated carbon anode can deliver an energy density of 31.6 Wh kg(-1) at a power density of 935 W kg(-1). The remarkable performance of binder-free MnMoO4 nH(2)O on Ni foam suggest their potential use as positive electrode material for high performance supercapacitors. (C) 2016 Elsevier Ltd. All rights reserved.