434739 Characterization of Conducting Poly(3,4-ethylenedioxithiophene) Polystyrene Sulfonate Surface Layers on Metal Oxide Particles

Thursday, November 12, 2015: 10:30 AM
Canyon B (Hilton Salt Lake City Center)
Jeffrey J. Richards1, Norman J. Wagner2 and Paul Butler1, (1)National Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, (2)Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE

Inexpensive grid-scale storage remains a major hurdle slowing the wide-scale adoption of renewable energy by public power utilities. Flow batteries have been proposed as one viable solution. Whereas, the capacity of a traditional battery is limited by its packaging, flow batteries pump redox active fluids from external storage tanks through a flow cell where electrical energy is extracted or stored via reversible redox reactions. In this way, the capacity of the battery becomes scalable independent of the specific redox chemistry and battery geometry. Semi-Solid flow batteries (SSFBs) use “flowable electrodes” for both the anode and cathode materials that consist of a mixture of lithiated metal oxide particles and carbon black particles. Typically, carbon black is added to these dispersions to improve the utilization of lithium as the particles flow by the electrodes. However, the presence of this percolated carbon black network also leads to significant and undesired increases in viscosity, both at low and high shear rates. In this work, we outline the synthesis of a composite polyelectrolyte/conjugated polymer surface layer on metal oxide particles that is designed to reduce or eliminate the need for added carbon black in the electrolytes. This layer is formed through the adsorption of poly(styrene sulfonate) onto oppositely charged metal oxide particles and subsequent polymerization of the surface polyelectrolyte with 3,4-ethylenedioxithiophene (EDOT) monomer. The PEDOT:PSS layer is characterized using a combination of light scattering, neutron scattering and dielectric spectroscopy to understand the connection between the surface layer’s composition, nanostructure and electrical properties. This process results in a conductive nanoscale PEDOT:PSS layer on the surface of the particle. In this talk, we demonstrate the feasibility and versatility of the approach.

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See more of this Session: Colloidal Dispersions I
See more of this Group/Topical: Engineering Sciences and Fundamentals