Temperature, effect voltage losses

Corresponding to the charge in the potential of single electrodes which is related to their different overpotentials, a shift in the overall cell voltage is observed. Moreover, an increasing cell temperature can be noticed. Besides Joule-effect heat losses Wj, caused by voltage drops due to the internal resistance Rt (electrolyte, contact to the electrodes, etc.) of the cell, thermal losses WK (related to overpotentials) are the reason for this phenomenon. 

The effect of electrolyte composition on conductivity is complex. Typically, in relatively dilute solutions conductivity increases with concentration. Above a certain value of concentration the effect is reversed typical conductivity maxima result. This is true of electrolyte solutions of strong electrolytes such as NaCl, KOH, and HCl at temperatures approaching 100°C, they have conductivities of lOOmho/m at molarities of 4-6 M. Such conditions are typical of water and chlorine electrolyzers and mean that ohmic voltage losses are of the order of lOmV/mm interelectrode gap/(kAm" ). 

The electrode kinetics and effects on the ES electrochemical performance have also been studied. At an extremely low kinetic rate, capacitance loss accompanied by an increase in series resistance could occur, leading to aging. This aging is accelerated at both high temperatures and voltages. 

Material response is typically studied using either direct (constant) applied voltage (DC) or alternating applied voltage (AC). The AC response as a function of frequency is characteristic of a material. In the future, such electric spectra may be used as a product identification tool, much like IR spectroscopy. Factors such as current strength, duration of measurement, specimen shape, temperature, and applied pressure affect the electric responses of materials. The response may be delayed because of a number of factors including the interaction between polymer chains, the presence within the chain of specific molecular groupings, and effects related to interactions in the specific atoms themselves. A number of properties, such as relaxation time, power loss, dissipation factor, and power factor are measures of this lag. The movement of dipoles (related to the dipole polarization (P) within a polymer can be divided into two types an orientation polarization (P ) and a dislocation or induced polarization. 

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