Cassette less SOFC stack and method of assembly
A cassette less SOFC assembly and a method for creating such an assembly. The SOFC stack is characterized by an electrically isolated stack current path which allows welded interconnection between frame portions of the stack. In one embodiment electrically isolating a current path comprises the step of sealing a interconnect plate to a interconnect plate frame with an insulating seal. This enables the current path portion to be isolated from the structural frame an enables the cell frame to be welded together.
1. A method for constructing a cassette less SOFC stack characterized by electrically isolating a stack current path and frames of the stack; and directly welding the frames of the stack together layer by layer to form the stack.
2. The method of claim 1 wherein said step of electrically isolating a current path comprises the step of sealing a interconnect plate to a interconnect plate frame with an insulating seal.
3. The method of claim 2 wherein said insulating seal is a glass seal.
4. The method of claim 2 further comprising the step of welding said interconnect plate frame to a cell frame.
5. The method of claim 4 further comprising the step of inserting an interconnect mesh within said current path to maintain electrical connection.
6. An SOFC stack characterized by a fuel stack having a welded metal frame defining a stack current flow path having electrically isolated electrical portions positioned therein; wherein individual frames of the stack are directly welded together layer by layer to form the stack.
7. The SOFC stack of claim 6 wherein an interconnect plate within said current flow path is electrically isolated from an interconnect plate frame by an insulative seal.
8. The SOFC stack of claim 6 wherein said electrical portions include anodes and cathodes.
9. The SOFC stack of claim 8 wherein said electrical portions further include interconnected mesh.