Asymmetric Supercapacitors Based on Reduced Graphene Oxide with Different Polyoxometalates as Positive and Negative Electrodes

Nanofabrication using a "bottom-up" approach of hybrid electrode materials into a well-defined architecture is essential for next-generation miniaturized energy storage devices. This paper describes the design and fabrication of reduced graphene oxide (rGO)/polyoxometalate (POM)-based hybr...

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Detalles Bibliográficos
Autores: Dubal, Deepak P.|||0000-0002-2337-676X, Chodankar, Nilesh R.|||0000-0002-1174-2064, Vinu, Ajayan, Kim, Do-Heyoung|||0000-0001-7949-2252, Gómez-Romero, Pedro|||0000-0002-6208-5340
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:225303
Acceso en línea:https://ddd.uab.cat/record/225303
https://dx.doi.org/urn:doi:10.1002/cssc.201700792
Access Level:acceso abierto
Palabra clave:Asymmetric supercapacitors
Carbon
Hybrid materials
Polyoxometalates
Reduced graphene oxide
Descripción
Sumario:Nanofabrication using a "bottom-up" approach of hybrid electrode materials into a well-defined architecture is essential for next-generation miniaturized energy storage devices. This paper describes the design and fabrication of reduced graphene oxide (rGO)/polyoxometalate (POM)-based hybrid electrode materials and their successful exploitation for asymmetric supercapacitors. First, redox active nanoclusters of POMs [phosphomolybdic acid (PMo) and phosphotungstic acid (PW)] were uniformly decorated on the surface of rGO nanosheets to take full advantage of both charge-storing mechanisms (faradaic from POMs and electric double layer from rGO). The as-synthesized rGO-PMo and rGO-PW hybrid electrodes exhibited impressive electrochemical performances with specific capacitances of 299 (269 mF cm) and 370 F g (369 mF cm) in 1 m HSO as electrolyte at 5 mA cm. An asymmetric supercapacitor was then fabricated using rGO-PMo as the positive and rGO-PW as the negative electrode. This rGO-PMo∥rGO-PW asymmetric cell could be successfully cycled in a wide voltage window up to 1.6 V and hence exhibited an excellent energy density of 39 Wh kg (1.3 mWh cm) at a power density of 658 W kg (23 mW cm).