Applications of electrodeposition

Available cell designs for recovery of metal ions from dilute solutions can be put into the two general categories direct metal recovery or indirect recovery as a metal ion concentrate (concentrator cells). In both these categories two- and three-dimensional electrodes are used. A range of cells used for metal recovery and deposition [7] is shown in Table 11.2, virtually all of which have seen some commercial application. 

In the Reconwin cell [9] a uniform curtain of fine air bubbles is directed across the face of the cathode to increase the mass transfer coefficient in comparison to unagitated or recirculated electrolyte systems. Typically, at a concentration of 1 g dm, the limiting current for say copper deposition is approximately 100 A m . The cathode material is a permanent metal (stainless steel) blank of approximate size 0.6 m by 0.6 m, from which the electrodeposited metal is recovered as foil. The cell is used in an undivided configuration in which both sides of the cathode are active. 

The use of a concentric cathode cell [10] has been described for the recovery of precious metal on a small scale (Wilson Process Systems), from spent photographic solutions and from electroplating and refining wastes. The recovery of the metal is by manually scraping from the cathode or by furnace refining in the case of gold. 

2 Rotating electrode cells. Cells for industrial applications which utilise rotation of the cathode are either discs or cylinders. They can produce the metal deposit as a powder or a particulate which enables the cell to be operated in a continuous mode when the powder is displaced freely from the electrode surface. 

A second device based on the movement of a cylindrical cathode is the impact rod or rotating tubular reactor [12]. This cell uses a set of rod 

Heat-resistant oxide coatings for tube cathodes  

Ceramic/metal coatings for wear/corrosion resistance  

Thin-film dielectric coatings for capacitors Thick-film substrates for hybrid circuits Glass passivation of semiconductor surfaces  

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S. Krongelb, J. O. Dukovic, M. L. Komsa, S. Mehdizadeh, L. T. Romankiw, P. C. Andricacos, A. T. Pfeiffer, and K. Wong, The Application of Electrodeposition Processes to Advanced Package Fabrication, SPIE International Conference on Advances in Interconnection and Packaging, 1389, 249-256 (1990). 

This chapter concerns with theory and application of electrodeposition techniques used for fabrication of components for high and low temperature fuel cells, supercapacitors, and lithium ion batteries. Recent progress and possible future research directions in each field will be discussed. 

R.S. Jayashree, IS. Spendelow, I Yeom, C. Rastogi, M.A. Shannon, and P.IA. Kenis, Characterization and application of electrodeposited Pt, Pt/Pd, and Pd catalyst structures for direct formic acid micro fuel cells, Electrochimica Acta, 50(24) (2005) 4674 682. 

Advances in electrochemical knowledge and techniques have led to evermore sophisticated applications of electrodeposition. For example, knowledge of electrode potentials has made the electrodeposition of alloys possible and commercial. Methods have also been discovered to provide plastics with metal coatings. Similar techniques have been discovered to coat such rubber articles as gloves with a metallic layer. Worn or damaged metal objects can be returned to pristine condition by a process called electroforming. Some commercial metal objects, such as tubes, sheets, and machine parts, have been totally manufactured by electrodeposition (sometimes called electromachining). 

The early applications of electrodeposition were mainly confined to situations where relatively thick polycrystalline metal deposits were needed. These included protective or sacrificial metal layers for corrosion protection, decorative applications, and for coatings with specific mechanical properties. However, in the last several decades, electrodeposition has been proven to be one of the enabling fabrication methods behind the train of hi-tech enterprises. There are many examples where electrodeposition is used as convenient if not the approach to deliver the desired structures, mate-... 

The third section has three chapters. Chapter 10 analyzes the Laser Interference Metallurgy which allows the creation of periodic patterns with a well-defined long-range order at the scale of typical microstructures (from the sub micrometer level up to micrometers). Chapter 11 discusses general phenomena involved in electrodeposition process, commonly used techniques and application of electrodeposition in different areas of research and industry. Lastly, Chap. 12 describes the plasma state and its application to modify surfaces in order to obtain a desired functional property in the biomedical field. 

As with any other surface coating, it is the final s lication which governs the choice of the chemical structure of the polymer, because the performance of the film depends more on its chemical structure than on the particular method of applying the film. However, it is worth going through the major requirements of the most common applications of electrodeposited films. 

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