Electronic Conductivity of Graphite Fiber Fixed‐Bed Electrodes

Experiments have been done to obtain the electronic conductivity of graphite fiber fixed‐bed electrodes. Voltage drop in dry stacks of graphite fiber mat, felt, and cloth under varying degrees of mechanical compression was measured at room temperature for superficial current densities up to 0.7 kA/m 2 . The transverse conductivity of the fiber matrix calculated from these data show that the conductivity depends primarily on contact resistance between fibers and that conductivity can be controlled in the range about 10–450 mho/m by compression of the matrix. The degree of matrix compression is accounted for by the change in matrix porosity and matrix conductivity can be calculated approximately by the correlation This electronic conductivity is in the same order as the ionic conductivity of strong aqueous electrolytes so that matrix compression can be used as a design variable to manipulate potential distribution in graphite fiber fixed‐bed electrodes.