Hybrid graphene-polyoxometalates nanofluids as liquid electrodes for dual energy storage in novel flow cells

Solid Hybrid materials abound. But flowing versions of them are new actors in the materials science landscape and in particular for energy applications. This paper presents a new way to deliver nanostructured hybrid materials for energy storage, namely, in the form of nanofluids. We present here the...

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Detalles Bibliográficos
Autores: Dubal, Deepak P.|||0000-0002-2337-676X, Rueda García, Daniel|||0000-0003-3539-1585, Marchante, Carlos|||0000-0002-2296-0112, Benages-Vilau, Raúl|||0000-0003-0875-124X, Gómez-Romero, Pedro|||0000-0002-6208-5340
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:214999
Acceso en línea:https://ddd.uab.cat/record/214999
https://dx.doi.org/urn:doi:10.1002/tcr.201700116
Access Level:acceso abierto
Palabra clave:Electroactive Nanofluids
Reduced Graphene Oxide (RGO)
Polyoxometalates
Hybrid materials
Descripción
Sumario:Solid Hybrid materials abound. But flowing versions of them are new actors in the materials science landscape and in particular for energy applications. This paper presents a new way to deliver nanostructured hybrid materials for energy storage, namely, in the form of nanofluids. We present here the first example of a hybrid electroactive nanofluid (HENFs) combining capacitive and faradaic energy storage mechanisms in a single fluid material. This liquid electrode is composed of reduced graphene oxide and polyoxometalates (rGO-POMs) forming a stable nanocomposite for electrochemical energy storage in novel Nanofluid Flow Cells. Two graphene based hybrid materials (rGO-phosphomolybdate, rGO-PMo₁₂ and rGO-phosphotungstate, rGO-PW₁₂) were synthesized and dispersed with the aid of a surfactant in 1 M H₂SO₄ aqueous electrolyte to yield highly stable hybrid electroactive nanofluids (HENFs) of low viscosity which were tested in a home-made flow cell under static and continuous flowing conditions. Remarkably, even low concentration rGO-POMs HENFs (0.025 wt%) exhibited high specific capacitances of 273 F/g(rGO-PW₁₂) and 305 F/g(rGO-PMo₁₂) with high specific energy and specific power. Moreover, rGO-POM HENFs show excellent cycling stability (∼95 %) as well as Coulombic efficiency (∼77-79 %) after 2000 cycles. Thus, rGO-POM HENFs effectively behave as real liquid electrodes with excellent properties, demonstrating the possible future application of HENFs for dual energy storage in a new generation of Nanofluid Flow Cells.