Aerogel and xerogel composites for use as carbon anodes
View Patent ↗A method for forming a reinforced rigid anode monolith and fuel and product of such method. The method includes providing a solution of organic aerogel or xerogel precursors including at least one of a phenolic resin, phenol (hydroxybenzene), resorcinol(1,3-dihydroxybenzene), or catechol(1,2-dihydroxybenzene); at least one aldehyde compound selected from the group consisting of formaldehyde, acetaldehyde, and furfuraldehyde; and an alkali carbonate or phosphoric acid catalyst; adding internal reinforcement materials comprising carbon to said precursor solution to form a precursor mixture; gelling said precursor mixture to form a composite gel; drying said composite gel; and pyrolyzing said composite gel to form a wettable aerogel/carbon composite or a wettable xerogel/carbon composite, wherein said composites comprise chars and said internal reinforcement materials, and wherein said composite is suitable for use as an anode with the chars being fuel capable of being combusted in a molten salt electrochemical fuel cell in the range from 500 C to 800 C to produce electrical energy. Additional methods and systems/compositions are also provided.
1. A method for producing a reinforced rigid anode monolith and fuel, the method comprising:
providing a solution of organic aerogel or xerogel precursors including at least one of a phenolic resin, phenol (hydroxybenzene), resorcinol(1, 3-dihydroxybenzene), or catechol(1,2-dihydroxybenzene); at least one aldehyde compound selected from the group consisting of formaldehyde, acetaldehyde, and furfuraldehyde; and a transition metal oxide catalyst;
adding internal reinforcement materials selected from (1) ceramic materials; (2) glassy materials based on borates, phosphates, or silicates with alkaline earth or transition metal cations; and/or (3) carbon materials to said precursor solution to form a precursor mixture;
gelling said precursor mixture to form a composite gel;
drying said composite gel; and
pyrolyzing said composite gel to form an aerogel/carbon composite or a xerogel/carbon composite wherein said composites comprise chars and said internal reinforcement materials, and said chars are fuel capable of being combusted in a molten salt electrochemical fuel cell in the range from 500 C to 800 C to produce electrical energy.
2. The method recited in claim 1 , wherein said drying is accomplished by supercritical-critical solvent extraction.
3. The method recited in claim 1 , wherein said drying is accomplished by air drying.
4. The method recited in claim 1 , wherein said ceramic materials arc selected from the group consisting of silica, aluminosilicates, and ash derived from coal or petroleum clays.
5. The method recited in claim 1 , wherein said carbon materials are selected from the group consisting of carbon :fibers, carbon paper, carbon rods, carbon fabrics, carbon screens, graphite or highly graphitized carbon structures.
6. The method recited in claim 1 wherein said composites have a density of at least 0.56 grams/cm 3 .
7. The method recited in claim 6 wherein said carbon materials comprise graphite.
8. The method recited in claim 1 wherein the pyrolizing is conducted in the presence of a material selected from the group consisting of alkali carbonate, alkaline earth carbonate or phosphoric acid, halide salts, and salts based on sodium aluminum hexafluoride.
9. The method recited in claim 1 , wherein pyrolyzing said composite gel forms a wettable aerogel/carbon composite or a wettable xerogel/carbon composite.