Two Coordination Polymers@Graphene Hybrid Electrodes for High‐Performance Supercapacitors with Enhanced Rate Capability and Specific Capacitance

Abstract

AbstractHybrids of polyoxometalate(POM)/transition‐metal complexes/graphene‐based electrode materials not only integrate the advantages of the individual components completely but also ameliorate the shortcomings to some extent, providing an efficient approach to fabricate high‐performance supercapacitors. In this work, we synthesized two novel isostructural compounds (Co(itmb)4[H2VW12O40] ⋅ 4H2O (1) and Zn(itmb)4[H2VW12O40] ⋅ 3H2O (2)) based on the Keggin ions via a hydrothermal method (itmb=1‐(imidazo‐1‐ly)‐4‐(1,2,4‐triazol‐1‐ylmethyl)benzene). The specific capacitance of 1@50 %graphene (405.3 F g−1) and 2@50 %graphene (339.2 F g−1) were 1.33 and 1.19 times of 1 and 2, respectively. In addition, the 1@50 %graphene (93.5 %) and 2@50 %graphene (96 %) possess higher rate performance than 1 (90 %) and 2 (91 %), suggesting a significant enhancement of the electrical performance.