Foam electrodes

For increased power requirements, electrode constructions have been developed which bring the electronic conductors in closer contact with the active material particles first, around 1930, the sinter electrode [110], recently in sealed cells largely replaced by the nichel-foam electrode, and then, around 1980, the fiber structure electrode [111]. In order to take full advantage of their increased perform-... 

Ketec cell Eltech Vertical metal (or carbon) foam electrodes in a tank Discontinuous cathode steel (chemically stripped for reuse carbon No ... 

Other examples of conversion using a nickel oxide electrode are the oxidation of benzyl alcohols. A nickel foam electrode was used for oxidation [18] in this case and the mechanism was studied by... 

The application of a very similar system using foam electrodes has been patented by ICI pic [79] for the controlled fluorination of partially fluorinated volatile materials to give excellent yields of more highly fluorinated products. 

A nickel anode is in alkaline solution protected against corrosion by a layer of nickel oxides. oxide (NiOOH) is capable of oxidizing a number of functional groups primary alcohols may be oxidized to carboxylic acids [158-161], which is of interest for the technical production of an intermediate for vitamin C production [162]. NiOOH chemically oxidizes the substrate and is regenerated electrochemically a large anode surface, which is realized in the Swiss-roll cell (Chap. 31), is thus advantageous. NiOOH electrodes in form of nickel foam electrodes has been found to be useful for the oxidation of diacetone L-sorbose to diacetone 2-keto-L-gulonic acid in the vitamin C synthesis [163]. 

Mass transfer coefficient (k ) and pressure drop per unit electrode height were studied on both flow-through and flow-by nickel foam electrodes [31]. A comparison with older literature data suggests that the values of k are higher by a factor of... 

Y. Zhao, J. Liu, Y. Hu, H. Cheng, C. Hu, C. Jiang, L. Jiang, A. Cao, L. Qu, Highly Compression-Tolerant Supercapacitor Based on Polypyrrole-Mediated Graphene Foam Electrodes. Adv. Mater. 2013,25, 591-595. 

Wei et al. directly deposited the PPy-Ag composites on nickel foam via the redox reaction between Py and silver nitrate [76]. The nickel foam was able to accelerate the redox reaction and lead to the formation of PPy-Ag composites, which shows a strong adhesive force to the substrate. The high SC of 493 F/g at a current density of 1 A/g was determined for the PPy-Ag-nickel foam electrode. It decreased to 451.08 F/g in the first 150 circles, and it kept nearly unchanged in the subsequent 850 circles. It indicated that the PPy-Ag-modified nickel foam electrode might be promising and can be applied in flexible energy-storage devices. 

Retec cell (Eltech) Vertical metal or carbon foam electrodes (divided cell) Discontinuous by leaching or anodic dissolution... 

Panizza M, Solisio C, Cerisola G (1999) Electrochemical remediation of copper (II) from an industrial effluent Part II. Three-dimensional foam electrode. Resour Conserv Recy 27 299-307... 

The equilibrium potential of the nickel-hydroxide electrode is slightly above that of water decomposition. In this respect the situation resembles that of the lead-dioxide electrode, but the much lower value of this potential allows the use of nickel as conducting element, since corrosion of this metal can be neglected, at least under normal conditions. For this reason, corrosion is not shown in Fig. 1.31. (Only in foam electrodes with an extremely large surface area of the substrate, nickel corrosion may slightly disturb the current balance in sealed cells.)... 

Some of the earliest work on AAEM fuel cells was conducted by Agel et ai in 2001 [7], They used a KOH-doped membrane, carbon-supported Pt on nickel foam electrodes, and H2/O2 at atmospheric pressure and ambient temperature to obtain a current density of 25mAcm at 0.6 V. This study demonstrated the need for good ionic contact between the electrodes and the membrane, as the performance increased to just under 60mAcm at 0.6 V when an interfacial KOH gel was applied between them. 

Betaproteobacteria. Rhodoferax ferrireducens is an iron-reducing bacterium that was isolated from subsurface sediments, and shown to produce power in MFCs (Chaudhuri and Lovley 2003). Using glucose as an electron donor, 6.8 to 33 mW/m (graphite rods, carbon felt or foam electrodes) was produced with a two-chamber system. Coulombic efficiency was 83% with a poised potential working electrode and was 81% using ferricyanide at the cathode. Fructose, sucrose, and xylose also produced power. No mixed cultures were examined in the apparatus for comparison of power densities. 

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