Electrochemically produced powder particles

Dendrites are the most common shape of electrochemically produced powder particles [5]. Aside from dendrites, powder particles can be also obtained in the form of flakes, fibrous, spongy, wires, cauliflower-like, and the many other irregular forms. The powder particles can spontaneously fall off or can be removed from the... 

Maksimovic VM, Nikolic ND, Kusigerski VB, Blanusa JL (2015) Correlation between morphology and magnetic properties of electrochemically produced cobalt powder particles. J Serb Chem Soc 80 197-207... 

The anode is exposed to hydrogen or hydrocarbons as fuel. It should be a mixed conductor with dominantly electronic conducting to allow the transportation of the electrons produced as a result of the chemical reaction at the anode surface. The electrode composition, powder particle size, and the manufacturing method are important parameters that affect the electronic and ionic conductivity and the activity for the electrochemical reactions. The electrical resistance is composed... 

There are indeed some other methods for producing silicon-based nanocomposites that appeared in the literature. Considerable work has been performed by J. Dahn s group and the decomposition of silane or polysilane pitch within carbonaceous matrices has been widely explored. Other methods based on HEMM of electrochemically inactive phases such as iron, nickel, titanium-nickel, titanium-carbon, silicon-carbon, and so on also have been examined using silicon powder with an initial particle grain size within either micrometric or nanometric ranges. The common problem in all these cases is that it is difficult to predict theoretically the appropriate matrix/silicon particles combination, i.e., there is no simple guidance rule in order to make reasonable predictions. An overview of all the above-described methods is summarized in Table 11.3. 

Fig. 9.17 SEM images of the hollow copper particles produced by the galvanic deposition of copper onto aluminum powder in Cu (II) alkaline solutions (pH 14, room temperature) (Reproduced from Ref [3] with permission from The Electrochemical Society)...

Although electrochemically prepared polypyrrole films are useful for fiindam tal studies, they are not practical for use in fuel cells. Apart firom the difficulty of their large scale production, their permeability is insufficient for generation of the large current densities (> 500 mA cm required of commercial cells. To circumvent these problems, we have used chemically prepared polypyrrole/poly(styr e-4-sulphate) powders, which we have raidered c tatalytic by the chemical deposition of Pt particles by various methods (7-9). These polypyrrole supported Pt catalysts can easily be mass-produced, and can be formed into catalyst layers for fuel cell gas diffiision electrodes using the technology currently used commercially for carbon supported catal> ts. 

Because of its application in the manufacturing of porous metaUo-ceramic bearings, of friction materials, parts for machineiy, various alloys, in chemical industry, in manufacture of rechargeable batteries, etc., Fe powder is an important industrial product [55]. Significant amount of Fe powder is produced by electrochemical technique and 20% of electrodeposited Fe powders have to be blended with Fe powders produced by other procedures. The main advantage of electrodeposited Fe powder is its volumetric mass (1.5-2.2 g cm ) and its suitability for pressing, due to dendritic particle shape. 

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