Electrolyte resistivity

Tertiay Current Distribution. The current distribution is again impacted when the overpotential influence is that of concentration. As the limiting current density takes effect, this impact occurs. The result is that the higher current density is distorted toward the entrance of the cell. Because of the nonuniform electrolyte resistance, secondary and tertiary current distribution are further compHcated when there is gas evolution along the cell track. Examples of iavestigations ia this area are available (50—52). 

Figure 5.10 Variation of electrolyte resistance with speed...

The electrolytic resistance of the condensed layer parallel to the surface of the metal is high even when it contains dissolved acid fumes or chlorides. 

Bimetallic corrosion in atmospheres is confined to the area of the less noble metal in the vicinity of the bimetallic joint, owing to the high electrolytic resistance of the condensed electrolyte film. Electrolytic resistance considerations limit the effective anodic and cathodic areas to approximately equal size and therefore prevent alleviation of atmospheric galvanic corrosion through strict application of the catchment area principle. 

Establishing electrolyte resistivity To enable a satisfactory cathodic-protection scheme to be designed, it is necessary to determine the resistivity of the electrolyte (soil or water). This information is necessary to enable the current output of anodes to be determined together with their position and power source voltage, and it also provides an indication of the aggressiveness of the environment in general the lower the resistivity the more aggressive the environment. 

To measure structure/electrolyte potentials with electrolyte resistivities in excess of 2 kQ cm, a high-resistance potentiometer unit as shown in Fig. 10.43 or a potentiometric voltmeter as illustrated in Fig. 10.44 may be used. 

Instruments in this category are used for the measurement of electrolyte resistivity, resistance, and insulation (i.e. protective-wrap) conductivity. 

This is the ratio in which the current would divide, if electrolytic resistance were to control its flow entirely. The metal distribution ratio M is the ratio of the thicknesses of the coating actually deposited during a measurement. There are several numerical scales of throwing index T, but Field s is widely adopted ... 

On this scale, zero represents the case when M = P, and electrolyte resistance is the main factor. Throwing power can be worse, down to a limit T = - 100% when A/ = oo, i.e. no deposit at all on the far cathode. Conversely, when M < P, T is positive. Were M to reach 1-0 despite the difference in position, 7" = -F 100%. At one time +100% was regarded as an unrealisable limit, but conditions have been found for which T = -f150% in a Haring-Blum cell. 

The effect of paint films on the cathodic and anodic reactions will now be considered and the factors which influence the electrolytic resistance of paint films will be discussed. 

An examination has, therefore, been made of the effect of solutions of potassium chloride on the electrolytic resistance of films cast from a penta-erythritol alkyd, a phenolformaldehyde tung oil and an epoxypolyamide varnishPotassium chloride was chosen because its conductivity is well known and unpigmented films were first examined in order to eliminate the complexities of polymer/pigment interaction. 

The electrical resistance exerted by a separator on the ionic current is defined as the total resistance of the separator filled with electrolyte minus the resistance of a layer of electrolyte of equal thickness, but without the separator. The separator resistance has to be considered as an increment over the electrolyte resistance. 

This formula shows the factorial effect of the separator on the electrical resistance the measured resistance of the electrolyte-filled separator is the (T2]P) - fold multiple of the electrolyte resistance without the separator by definition, T2/P > 1. 

The prime requirements for the separators in alkaline storage batteries are on the one hand to maintain durably the distance between the electrodes, and on the other to permit the ionic current flow in as unhindered a manner as possible. Since the electrolyte participates only indirectly in the electrochemical reactions, and serves mainly as ion-transport medium, no excess of electrolyte is required, i.e., the electrodes can be spaced closely together in order not to suffer unnecessary power loss through additional electrolyte resistance. The separator is generally flat, without ribs. It has to be sufficiently absorbent and it also has to retain the electrolyte by capillary forces. The porosity should be at a maximum to keep the electrical resistance low (see Sec. 9.1.2.3) the pore size is governed by the risk of electronic shorts. For systems where the electrode substance... 

Part 1. The influence of the transition temperature on the electrolytic resistance... 

Makharia R, Mathias ME, Baker DR. 2005. Measurement of catalyst layer electrolyte resistance in PEECs using electrochemical impedance spectroscopy. J Electrochem Soc 152 A970-A977. 

Ikonopisov284 has conducted a systematic study of breakdown mechanisms in growing anodic oxides. He has enumerated factors significantly affecting the breakdown (nature of the anodized metal, electrolyte composition and resistivity) as well as those of less importance (current density, surface topography, temperature, etc.). By assuming a mechanism of avalanche multiplication of electrons injected into the oxide by the Schottky mechanism, Ikonopisov has correctly predicted the dependence of Ub on electrolyte resistivity and other breakdown features. 

The distribution of potential in TC is practically the same as that near the flat surface if the electrolyte concentration is about 1 mol/1 [2], So the discharge of TC may be considered as that of a double electric layer formed at the flat electrode surface/electrolyte solution interface, and hence, an equivalent circuit for the TC discharge may be presented as an RC circuit, where C is the double layer capacitance and R is the electrolyte resistance. 

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