Materials electrochemical compatibility

The primary purpose of a lead-acid battery is to store and discharge energy therefore, we must avoid any action that would diminish this primary function. As stated earlier, the primary role of the separator is to allow ionic flow while preventing electronic conductance. As we consider the different materials of construction of the battery, including the separator, we must also consider some important aspects regarding electrochemical compatibility. 

Some time ago, scientists at the Bell Laboratories developed the electrochemical compatibility test [9]. This test essentially utilizes cyclic voltammetry equipment that screens materials to determine the influence on pure lead electrodes over the whole range of charging and discharging voltages. 

Materials of construction for the zinc/mercuric oxide cells are limited not only by their ability to survive continuous contact with strong caustic alkali, but also by their electrochemical compatibility with the electrode materials. As far as the external contacts are concerned, these are decided by corrosion resistance, compatibility with the equipment interface with respect to galvanic corrosion, and, to some degree, cosmetic appearance. Metal parts may be homogeneous, plated metal, or clad metal. Insulating parts may be injection-, compression-, or transfer-molded polymers or rubbers. 

There are, however, numerous appHcations forthcoming ia medium- to small-scale processiag. Especially attractive on this scale is the pharmaceutical fine chemical or high value added chemical synthesis (see Fine chemicals). In these processes multistep reactions are common, and an electroorganic reaction step can aid ia process simplification. Off the shelf lab electrochemical cells, which have scaled-up versions, are also available. The materials of constmction for these cells are compatible with most organic chemicals. 

An electrolyte may be characterized by resistance / [Qcm], which is defined as the resistance of the solution between two electrodes at a distance of 1 cm and an area of 1 cm2. The reciprocal value is called the specific conductivity at[Q" cm"1] [5], For comparison the values of k for various materials are given in Fig. 2 Here is a wide spread for different electrolyte solutions. The selection of a suitable, high-conductivity electrolyte solution for an electrochemical cell depends on its compatibility with other components, such as the positive and negative electrodes. 

Part of the wide acceptance of plastics is from their relative compatibility to chemicals as compared to that of other materials. Because plastics are largely immune to the electrochemical corrosion to which metals are susceptible, they can frequently be used profitably to contain water and corrosive chemicals that would attack metals. Plastics are often used in corrosive environments for... 

A major challenge in providing electrical power for implantable devices is the isolation of toxic or bio-incompatible materials. As the size of the device decreases to a centimeter or millimeter scale, the parts responsible for isolation, such as canisters and seals, begin to determine the size of the device. An alternative is to design an electrochemical system that is compatible with the physiological environment and can take advantage of chemical species available in that environment, specifically the... 

To prepare crystalline surfaces, usually the starting material is a suitable, pure, three-dimensional single crystal. From this crystal, a slice of the desired orientation is cut. Therefore the crystal must be oriented. Orientation is measured by X-ray diffraction. Hard materials are then grounded and polished. Soft materials are cleaned chemically or electrochemically. The surfaces are still mechanically stressed, contaminated, or chemically changed, e.g. oxidized. In principle, electrochemical processes in liquid can be used to generate clean crystalline surfaces. The problem is that an electrochemical setup is not compatible with an UHV... 

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