Characterization of Carbon Black Particles for Use in Aqueous Slurry Electrodes

Flowable slurry electrodes have received renewed interest in recent years for use in electrochemical systems. Applications include, but are not limited to, electrochemical energy storage (e.g. flow batteries^1,2 and electrochemical flow capacitors³) and desalination (e.g. flow electrode capacitive desalination systems⁴). All of these applications share similar, but distinctly different, requirements for the solid constituent of the slurry. For example, some systems might favor high electronic conductivity while others could place more of a premium on possessing a high specific surface area.

Carbon particles are often used as the solid constituent in these slurries as they often possess high values of both of these desirable properties. Carbons slurries examined in past research have included activated carbons, carbon blacks, and other more exotic carbons (multi-walled carbon nanotubes, graphene, etc.)⁵. The selection of slurry constituents inevitably involves trade-offs, however. While activated carbons may possess high specific areas, slurries composed of these particles have low conductivities. Conversely, highly conductive carbons generally do not possess high specific areas. For any of these particles, if the surface chemistry does not permit high loadings, then both the specific area and the conductivity are likely to suffer.

In this presentation we will discuss how the optimal selection of slurry properties varies depending on the given application in which the slurry electrode is intended to be used. The slurry properties of a wide array of different carbon black particles in aqueous electrolytes will also be presented, and good candidates for use in specific electrochemical systems will be discussed.

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[2] T. Petek, N. Hoyt, J. Wainright and R. Savinell, "Slurry Electrodes for Iron Plating in an All-Iron Flow Battery," submitted to J. Power Sources, 2015.

[3] V. Presser, C. Dennison, J. Campos, K. Knehr, E. Kumbur, Y. Gogotsi, Advanced Energy Materials, 2, 895-902 (2012)

[4] S. Jeon, H. Park, J. Yeo, S. Yang, C.H. Cho, M.H. Han, D.K. Kim, Energy Environ. Sci., 6, 1471 (2013)

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