Electrode contact resistance

It is important to note that based on Equation 1 the contact resistance is only dependent on the applied force and the hardness of the softer contact material, not on the apparent area of the contact. Due to this, whether the contact is a point or line, or the number of contacts per electrode, makes no difference to the electrode contact resistance by this theory. 

Voltmeters and potentiometers The instruments described here are generally referred to as corrosion voltmeters. As mentioned previously, the current flowing through any potential-measurement circuit must be small to avoid errors due to polarisation. Moreover, if the current flow is too large, errors will be introduced owing to the voltage drop caused by the contact resistance between the reference electrode and the electrolyte. It is thus clear that the prime requirement of a potential measurement circuit is high resistance. 

Activated carbons possess sufficient volumetric conductivity for electrolyte/collector current interchange. However, contact resistance between carbon particles in the electrode limits charge/discharge currents of the porous volumetric system and therefore EC s power capability. 

Electrode pressure on the sample material approximately corresponded to the pressure used in a practical EC in its operational mode and was equal to 8 kgf-cm 2 (this pressure was applied for purposes of minimization of particle contact resistance). 

In accordance with this model, the current path is made through the contact resistance external collector - volume collectors (Rki), then goes through many other resistances, such as bulk resistance of the conductive particles (Rvi) and the contact resistance between the conductive particles in the volume of the electrode (Rci) at the end, there is contact resistance between the conductive particles and active mass particles (Rmi). 

Considering this chain of electrical resistors, we should take into account the influence of the binder (dielectric) effecting on all the above contact resistances in the circuit and increasing their value (Rb). Evidently, the main influence on the ESR of electrode is this circuit because of a big number of contact resistances distributed in the bulk of the electrode. 

Fig.4.4. Schematic of the functional elements of the microhotplate. Rheat denotes the heating resistance, Rs is the metal-oxide resistance measured between the electrode contacts E+ and E-, and Rr is the temperaturesensor resistance...

On anti-static and conducting products, it is usual to measure the resistance between specified points. More or less efficient electrode systems are used, contact resistance included and the resistance usually measured with a commercial insulation tester. The relevant international method is ISO 287820. This used to be used in conjunction with two specifications (ISO 2882 and 2883) for antistatic and conductive products and, consequently, had procedures detailing the electrodes to be used for the products in those standards. ISO 2882 and 2883 were withdrawn, largely because of no... 

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