Solid oxide fuel cell stack
Disclosed is a solid oxide fuel cell stack. The solid oxide fuel cell stack includes a unit cell, a cell frame configured to support an edge of the unit cell, a interconnecting member disposed under the cell frame, a sealing member disposed between the cell frame and the interconnecting member, and a spacer member configured to uniformly maintain an interval between the cell frame and the interconnecting member. The spacer member is disposed at an area between the cell frame and the interconnecting member, which is not sealed by the sealing member, and formed of a mica or insulating ceramic.
1. A solid oxide fuel cell stack comprising:
a unit cell of a solid oxide fuel cell;
a cell frame configured to support an edge portion of the unit cell;
an interconnecting member disposed under the cell frame and electrically connected with the unit cell;
a sealing member disposed between a first area of a lower surface of the cell frame and the interconnecting member and formed of a glass material or a complex material of glass and ceramic;
a spacer member disposed between a second area, which is adjacent to the first area, of the lower surface of the cell frame and the interconnecting member, and formed of a mica or an insulating ceramic which has a transition temperature greater than that of the material of the sealing member, and configured to uniformly maintain an interval between the cell frame and the interconnecting member;
an upper plate and a lower plate interposing the unit cell, the cell frame, the interconnecting member, the sealing member, and the spacer member therebetween; and
a fastening member comprising a bolt passing through the upper plate, the cell frame, the interconnecting member, and the lower plate, a nut fastened to one end of the bolt, a washer disposed between the nut and the upper plate or between the nut and the lower plate and formed of a material having a greater thermal expansion coefficient than that of the bolt, and a tubular member disposed within a through hole which is formed in a stack of the upper plate, the unit cell, the cell frame, the interconnecting member, the sealing member, the spacer member, and the lower plate and formed of an insulating material,
wherein the bolt passes through the tubular member.
2. The solid oxide fuel cell stack of claim 1 , wherein the bolt comprises an insulating film formed on a surface thereof and formed of an insulating ceramic or glass material.
3. The solid oxide fuel cell stack of claim 1 ,
wherein the spacer member comprises a fastening hole into which the fastening member is inserted.
4. The solid oxide fuel cell stack of claim 3 , wherein the cell frame and the interconnecting member have a plurality of corners, and the spacer member comprises a plurality of corner spacers disposed to be adjacent to the plurality of corners, respectively, and the fastening member comprises a plurality of bolts which pass through the plurality of corner spacers, respectively.
5. The solid oxide fuel cell stack of claim 4 , wherein each of the corner spacers comprises a coating film formed on one of a surface of the cell frame and a surface of the interconnecting member.
6. The solid oxide fuel cell stack of claim 1 ,
wherein the spacer member comprises a plurality of spacer patterns disposed to be adjacent to the fastening member.
7. The solid oxide fuel cell stack of claim 6 , wherein an insertion groove into which the spacer pattern is inserted is formed in one of a surface of the cell frame and a surface of the interconnecting member.