Coated powder for electrolyte matrix for carbonate fuel cell

Claim 1

A process for producing a porous electrolyte tape for holding electrolyte in a molten carbonate fuel cell comprising providing electrolyte carbonate-coated ceramic particles wherein the carbonate ranges from about 5% by volume to about 30% by volume of said coated ceramic particles and wherein no significant portion of said ceramic particle is exposed, said electrolyte carbonate coating consisting of a carbonate useful as an electrolyte in a molten carbonate fuel cell, said ceramic particles ranging in diameter from about 0.1 micron to about 5 microns, said carbonate-coated ceramic particle not differing significantly in diameter from said ceramic particle, said ceramic particles not being significantly deleteriously effected by said molten carbonate fuel cell, admixing said coated ceramic particles with an organic binding agent, said binding agent being a solid at room temperature but fluid at elevated temperature and heat-decomposable below 400° C. vaporizing away leaving no significant residue, said binding agent being used in an amount sufficient to bind said coated particles together to produce a self-supporting tape from which said binding agent can be vaporized away leaving no significant residue and leaving said porous electrolyte tape, shaping said mixture into said binding agent-containing tape, and heating said binding agent-containing tape to decompose and vaporize away said binding agent producing said porous electrolyte tape, said porous electrolyte tape consisting essentially of said electrolyte carbonate-coated particles, said tape being less than 760 microns in thickness but having a thickness substantially greater than the diameter of the ceramic particles and that thickness encompassing a plurality of particles with a porosity ranging from about 30% by volume to about 65% by volume of the total volume of said tape and a pore size ranging from about 0.2 micron to about 2 microns.