Felt electrodes of nickel or titanium for many purposes. Precision cut (either 2.5 cm x 2.5 cm OR 5.0 cm x 5.0 cm) or in sheets of 20cm x 30cm. Felt electrodes are fibers of the materials that are sintered to a uniform and porous material.
Variants are shown below:
The porosity is 1 minus the ratio between the apparent density of the felt and theoretical density of the element. Both the area weight and porosity may vary.
