title: Tunable Oxygen Functional Groups as Electrocatalysts on Graphite Felt Surfaces for All-Vanadium Flow Batteries.
abstract: A dual oxidative approach using O2 plasma followed by treatment with H2 O2 to impart oxygen functional groups onto the surface of a graphite felt electrode. When used as electrodes for an all-vanadium redox flow battery (VRB) system, the energy efficiency of the cell is enhanced by 8.2 % at a current density of 150 mA cm(-2) compared with one oxidized by thermal treatment in air. More importantly, by varying the oxidative techniques, the amount and type of oxygen groups was tailored and their effects were elucidated. It was found that O-C=O groups improve the cells performance whereas the C-O and C=O groups degrade it. The reason for the increased performance was found to be a reduction in the cell overpotential after functionalization of the graphite felt electrode. This work reveals a route for functionalizing carbon electrodes to improve the performance of VRB cells. This approach can lower the cost of VRB cells and pave the way for more commercially viable stationary energy storage systems that can be used for intermittent renewable energy storage.
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Luis
authors.initials: L
authors.lastname: Estevez
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: David
authors.initials: D
authors.lastname: Reed
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Zimin
authors.initials: Z
authors.lastname: Nie
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Ashleigh M
authors.initials: AM
authors.lastname: Schwarz
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Manjula I
authors.initials: MI
authors.lastname: Nandasiri
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: Kizewski
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Edwin
authors.initials: E
authors.lastname: Thomsen
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Ji-Guang
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Sprenkle
authors.affiliation: Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA. bin.li@pnnl.gov.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
mesh_terms: D002384:Catalysis; D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D058626:Plasma Gases / Q000737:chemistry; D014639:Vanadium / Q000737:chemistry*
chemical_list: D058626:Plasma Gases; D014639:Vanadium; D010100:Oxygen
keywords: carbon; electrode; oxygen functional group; plasma chemistry; vanadium flow battery