Solid oxide fuel cell generator including a glass sealant
View Patent ↗A solid oxide fuel cell generator is provided for electrochemically reacting a fuel gas with a flowing oxidant gas at an elevated temperature to produce power. The generator includes a generator section receiving a fuel gas and a plurality of elongated fuel cells extending through the generator section and having opposing open fuel cell ends for directing an oxidant gas between opposing plena in the generator. A sealant defines a seal on the fuel cells adjacent at least one of the fuel cell ends. The sealant is a modified lanthanum borate aluminosilicate glass composition having a minimal amount of boron oxide and silica, and in which the sealant maintains substantially constant physical characteristics throughout multiple thermal cycles.
1. A solid oxide fuel cell generator for electrochemically reacting a fuel gas with a flowing oxidant gas at an elevated temperature to produce power, said generator comprising
a generator section receiving a fuel gas;
a plurality of elongated fuel cells extending through said generator section and having opposing open fuel cell ends for directing an oxidant gas between opposing plena in said generator;
a sealant defining a seal on said fuel cells adjacent at least one of said fuel cell ends, said sealant comprising a lanthanum borate aluminosilicate glass composition;
wherein said fuel cells comprise a fuel electrode of nickel/yttria or scandia stabilized zirconia, an oxidant electrode of lanthanum manganite and an electrolyte of yttria or scandia stabilized zirconia, and said glass composition further comprises:
La 2 O 3 present in an amount up to about 20 mole %;
Al 2 O 3 present in an amount of between about 10 to about 20 mole %;
SrO present in an amount of between about 30 to about 40 mole %;
ZrO 2 present in an amount up to about 5 mole %;
at least one of YO 1.5 and ScO 1.5 present in an amount up to about 0.5 mole %; and
MgO present in an amount of between about 10 to about 30 mole %; and
wherein said glass composition includes B 2 O 3 and SiO 2 having a combined mole percent of less than 32%.
2. The generator of claim 1 , wherein the glass composition constituents are present as 4.3 mole % La 2 O 3 , 22.2 mole % B 2 O 3 , 9.2 mole % SiO 2 , 12.9 mole % Al 2 O 3 , 34.5 mole % SrO, 3.7 mole % ZrO 2 and YO 1.5 or ScO 1.5 ; and 13.2 mole % MgO.
3. A solid oxide fuel cell generator for electrochemically reacting a fuel gas with a flowing oxidant gas at an elevated temperature to produce power, said generator comprising:
a generator section receiving a fuel gas;
a plurality of elongated fuel cells extending through said generator section and having opposing open fuel cell ends for directing an oxidant gas between opposing plena in said generator;
a sealant defining a seal on said fuel cells adjacent at least one of said fuel cell ends, said sealant comprising a lanthanum borate aluminosilicate glass composition; and
wherein said lanthanum borate aluminosilicate glass composition includes La 2 O 3 present in an amount up to about 20 mole %, ZrO 2 present in an amount up to about 5 mole %, and at least one of YO 1.5 and ScO 1.5 present in an amount up to about 0.5 mole %; and wherein said glass composition further comprises: B 2 O 3 and SiO 2 having a combined mole percent of less than about 32%; Al 2 O 3 present in an amount of between about 10 to about 20 mole %; SrO present in an amount of between about 30 to about 40 mole %; and MgO present in an amount of between about 10 to about 30 mole %.
4. The generator of claim 3 , wherein said fuel cells comprise a fuel electrode of nickel/yttria or scandia stabilized zirconia, an oxidant electrode of lanthanum manganite and an electrolyte of yttria or scandia stabilized zirconia.
5. The generator of claim 3 , wherein the glass composition constituents are present as 4.3 mole % La 2 O 3 , 22.2 mole % B 2 O 3 , 9.2 mole % SiO 2 , 12.9 mole % Al 2 O 3 , 34.5 mole % SrO, 3.7 mole % ZrO 2 and YO 1.5 or ScO 1.5 , and 13.2 mole % MgO.