The structure of porous nickel electrodes made by the powder metallurgical method

Summary

• 1. The methods of mercury porosimetry, air pumping, and filtration of rarefied gas were used to determine the effective pore radii, coarse and fine pore volumes, and specific surface for sintered porous nickel materials.

• 2. A model has been proposed for the porous structure of the materials investigated, which takes into account the method of their preparation. The model comprises fine pores-spaces between the carbonyl nickel particles, having radii of the order of a few microns, as well as coarse poresvoids remaining after the vaporization of particles of the pore-forming agent, the size of which is of the order of hundreds of microns (up to 1 mm).

• 3. Using the model proposed, an analysis is made of the character of the relationship between the principal structural characteristics of specimens and the amount and particle size of the pore-forming agent employed in their preparation. Conditions under which a system of interconnecting coarse pores can exist in material have been determined.

• 4. The model proposed provides a satisfactory explanation of relationships between various structural characteristics measured by different methods; this confirms that the model is a faithful representation of the true structure of the specimens investigated.