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

摘要

Hybrids 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)H2VW12O40center dot 4H(2)O (1) and Zn(itmb)(4)H2VW12O40center dot 3H(2)O (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.