Hybrid Graphene ‐Polyoxometalates Nanofluids as Liquid Electrodes for Dual Energy Storage in Novel Flow Cells

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.
Source: Contrast Media and Molecular Imaging - Category: Radiology Authors: Tags: Personal Account Source Type: research