Premium
Hybrid Graphene‐Polyoxometalates Nanofluids as Liquid Electrodes for Dual Energy Storage in Novel Flow Cells
Author(s) -
Dubal Deepak P.,
RuedaGarcia Daniel,
Marchante Carlos,
Benages Raul,
GomezRomero Pedro
Publication year - 2018
Publication title -
the chemical record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.61
H-Index - 78
eISSN - 1528-0691
pISSN - 1527-8999
DOI - 10.1002/tcr.201700116
Subject(s) - nanofluid , graphene , materials science , energy storage , oxide , electrode , nanotechnology , electrolyte , chemical engineering , electrochemistry , nanocomposite , supercapacitor , faraday efficiency , nanoparticle , chemistry , metallurgy , thermodynamics , power (physics) , physics , engineering
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‐PMo 12 and rGO‐phosphotungstate, rGO‐PW 12 ) were synthesized and dispersed with the aid of a surfactant in 1 M H 2 SO 4 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‐PW 12 ) and 305 F/g(rGO‐PMo 12 ) 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.