A High‐Capacity Negative Electrode for Asymmetric Supercapacitors Based on a PMo<sub>12</sub> Coordination Polymer with Novel Water‐Assisted Proton Channels
Guangning Wang, Tingting Chen, Carlos J. Gómez‐García, Feng Zhang, Mingyi Zhang, Huiyuan Ma, Haijun Pang, Xinming Wang, Lichao Tan
Abstract
Abstract The development of a negative electrode for supercapacitors is a critical challenge for the next‐generation of energy‐storage devices. Herein, two new electrodes formed by the coordination polymers [Ni(itmb) 4 (HPMo 12 O 40 )]·2H 2 O ( 1 ) and [Zn(itmb) 3 (H 2 O)(HPMo 12 O 40 )]·4H 2 O ( 2 ) (itmb = 1‐(imidazo‐1‐ly)‐4‐(1,2,4‐triazol‐1‐ylmethyl)benzene), synthesized by a simple hydrothermal method, are described. Compounds 1 and 2 show high capacitances of 477.9 and 890.2 F g −1 , respectively. An asymmetric supercapacitor device assembled using 2 which has novel water‐assisted proton channels as negative electrode and active carbon as positive electrode shows ultrahigh energy density and power density of 23.4 W h kg −1 and 3864.4 W kg −1 , respectively. Moreover, the ability to feed a red light emitting diode (LED) also demonstrates the feasibility for practical use. The results allow a better elucidation of the storage mechanism in polyoxometalate‐based coordination polymers and provide a promising direction for exploring novel negative materials for new‐generation high‐performance supercapacitors.