Binder for electrolyte matrix for molten carbonate fuel cells
A binder solution for an electrolyte matrix for use with molten carbonate fuel cells is provided. The binder solution includes a first polymer with a molecular weight of less than about 150,000 and a second binder with a molecular weight of greater than about 200,000. The binder solution produces an electrolyte matrix with improved flexibility, matrix particle packing density, strength, and pore structure.
1. A green electrolyte matrix, comprising:
a support material;
an electrolyte material; and
a binder,
wherein the binder comprises a first polymer with a molecular weight of less than 150,000 and a second polymer with a molecular weight of greater than 200,000; and
wherein the green electrolyte matrix is configured to be installed in a fuel cell; and
wherein the binder is configured to be removed from the green electrolyte matrix when the fuel cell is initially conditioned, so as to define an electrolyte matrix that is free of pores with a size of 0.2 μm or greater.
2. The green electrolyte matrix of claim 1 , wherein the first polymer is present in the electrolyte matrix in an amount of 4 wt. % to 12 wt. %.
3. The green electrolyte matrix of claim 1 , wherein the first polymer comprises an ethyl methacrylate copolymer.
4. The green electrolyte matrix of claim 1 , wherein the second polymer is present in the electrolyte matrix in an amount of 0.1 wt. % to 3 wt. %.
5. The green electrolyte matrix of claim 1 , wherein the second polymer comprises a methyl methacrylate—butyl acrylate copolymer.
6. The green electrolyte matrix of claim 1 , wherein the molecular weight of the second polymer is at least twice the molecular weight of the first polymer.
7. The green electrolyte matrix of claim 1 , wherein the binder further comprises a plasticizer.
8. The green electrolyte matrix of claim 1 , wherein the support material comprises lithium aluminate.
9. The green electrolyte matrix of claim 1 , wherein the electrolyte material comprises lithium carbonate.
10. The green electrolyte matrix of claim 1 , further comprising a reinforcing material.
11. The green electrolyte matrix of claim 1 further comprising a cationic surfactant dispersant.
12. The green electrolyte matrix of claim 11 , wherein the cationic surfactant dispersant is a polyester-polyamine condensation powder.
13. The green electrolyte matrix of claim 7 , wherein the plasticizer is a butyl benzyl phthalate.