Bright deposition, with additives

The deposit of nickel on top of the copper provides the essential resistance of the system to corrosion. Generally it is deposited from a solution based on the familiar Watts formulation—300 g 1 1 nickel sulphate, 30 g 1 1 nickel chloride, and 40 g 1 1 boric acid—and as in the copper processes the solutions contain additives to help give a bright deposit with good levelling characteristics. 

Bronze, copper—tin alloy, electro deposits can be produced in thicker deposits using proprietary brightening additives in the plating solution, especially over a smooth bright substrate. The brightest deposit with better corrosion resistance is attained when bronze is plated over a bright nickel plate. However, direct plating over steel is not an uncommon practice. 

Bright nickel deposits are obtained from one of the above electrolytes with additives. Because of its low costs, the Watts electrolyte is the most often used base... 

Properties of deposits Deposits can be produced that are adherent, coherent and finely crystalline. Addition agents, e.g. organic sulphonamides can improve the deposit structure so that thick coatings can be produced free of nodules and blisters. The production of very smooth thick deposits of copper has been reported Thin deposits tend to reproduce the substrate topography, but some cases of levelling have been reported. The brightness tends to fall with increasing thickness. 

The future remains bright for the use of carbon materials in batteries. In the past several years, several new carbon materials have appeared mesophase pitch fibers, expanded graphite and carbon nanotubes. New electrolyte additives for Li-Ion permit the use of low cost PC based electrolytes with natural graphite anodes. Carbon nanotubes are attractive new materials and it appears that they will be available in quantity in the near future. They have a high ratio of the base plane to edge plain found in HOPG. The ultracapacitor application to deposit an electronically conductive polymer on the surface of a carbon nanotube may be the wave of the future. 

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