As porous carbon can absorb hydrogen ions or protons [176, 183], carbon slurry electrodes can replace fixed carbon electrodes and perform continuous charging and discharging operations like an EFC. This type of hydrogen storage system through a slurry electrode can also reduce the associated risks of high-pressure systems .
J. Appl. Electrochem.1997, 27, 147– 152, DOI: 10.1023/A:1018443705541 Journal of Applied Electrochemistry (1997), 27 (2), 147-152 CODEN: JAELBJ; ISSN: 0021-891X. (Chapman & Hall) A 'slurry electrode' is a suspension of particles with large double-layer capacity, such as activated carbon, in an electrolyte soln.
Ideal slurry electrodes have high elec. (both electronic and proton) cond. to minimise the elec. resistance and ohmic power loss, and low viscosity to minimise parasitic pumping power, while utilizing porous particles with high surface areas for hydrogen storage.
After initial development for wastewater treatment [28, 31], the application of slurry electrodes has been extended to energy storage solutions in recent years, including non-aqueous lithium-ion batteries [14, 15] and electrochemical flow capacitors [22, 23, , , ]. Carbon-based materials have been commonly used in slurry electrodes.
The electrochem. properties of the slurry electrodes tested in a static cell are similar to that of solid electrodes in conventional supercapacitors for both, large spherical and anisometric activated carbons. Flow properties of the slurry electrodes were obtained for shear rates corresponding to pumping shear rates by rheometry.
The inherent dynamic movement of suspended particles in the slurry electrode impedes the continuous network formation as compared to the solid carbon electrodes, resulting in lower electronic conductivity (0.1–1 mS.cm −1 with 25 wt.% carbon content) and cell efficiency [19, 25, 42, 73].