Fabrication of a monolithic solid oxide fuel cell
AssigneeAllied-Signal Inc.
InventorsDavid M. Kotchick, Nguyen Q. Minh
Life of this patent
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Abstract
A monolithic solid oxide fuel cell of the type characterized by a plurality of fuel and oxidant passageways extending through the core of the fuel cell. The fuel cell is constructed only of anode, cathode, electroylte and interconnect materials. The cell is constructed using multilayer tapes formed by first roll milling four individual tapes of cathode, electrolyte, anode, and interconnect material, and then roll milling the multilayer tape from the four tapes of a single material. Passageways are formed within the cathode and anode layers by roll milling elongated organic fibers into the tapes and burning out the fibers during the binder removal, sintering process. A manufacturing process is also disclosed.
Claims24
A method of making a solid oxide ceramic fuel cell comprising the steps of:
- mixing powders of cathode, electrolyte, anode and interconnect ceramics each separately with a binder and a plasticizer to form a batch of each of said materials;
- shaping said cathode batch into a cathode tape layer incorporating a plurality of oriented organic fibers therein;
- shaping said electrolyte batch into an electrolyte tape layer;
- shaping said anode batch into an anode tape layer incorporating a plurality of oriented organic fibers therein;
- shaping said interconnect batch into an interconnect tape layer said shaping of said batch materials into said tapes performed by a process selected from the group including rolling, milling, and calendering;
- assembling said cathode tape layer, electrolyte tape layer, anode tape layer, and interconnect tape layer together to form a multilayer tape;
- cutting a portion of said multilayer tape to a desired shape;
- processing said multilayered tape portion to remove said organic fibers from said cathode tape layer and said anode tape layer leaving a plurality of passageways within said cathode and said anode;
- and
- sintering said multilayer tape portion to form a fuel cell.
A method of making a solid oxide ceramic fuel cell comprising the steps of:
- assembling a plurality of multilayered tapes in a green state into a stacked array, said multilayered tapes each including tapes of cathode, electrolyte, anode, and interconnect ceramic materials mixed with a binder and a plasticizer, said anode and said cathode tapes also including a plurality of oriented fibers therein, said stacked array being substantially free of voids or open spaces;
- heating said stacked array within a furnace the temperature of which is increased at a pressurized rate up to about 500 degrees centigrade to remove both said binder and said plasticizer, and also to remove said oriented fibers from said cathode tape and said anode tape thereby to form a plurality of passageways there within;
- and
- sintering said processed stacked array to form a monolithic fuel cell.
A method of making a monolithic solid oxide fuel cell comprising the steps of:
- preparing powders of strontium-doped lanthanum manganite for a cathode, yttria-stabilized zirconia for an electrolyte, magnesium-doped lanthanum chromite for an interconnect and a cermet of metal with stabilized zirconia for an anode to have a particle size in the range of from 0.1 micron to 10 microns;
- mixing said powders of cathode, electrolyte, anode and interconnect each separately with a binder and a plasticizer to form a batch of each of said materials;
- forming a cathode layer from said batch of cathode material and incorporating a plurality of oriented fibers therein;
- forming an electrolyte layer from said batch of electrolyte material;
- forming an anode layer from said batch of anode material and incorporating a plurality of oriented fibers therein;
- forming an interconnect layer from said batch of interconnect material;
- interbounding said cathode layer, said electrolyte layer, said anode layer and said interconnect layer together to form a multilayer tape having a thickness of from about 0.008 centimeters to 0.1 centimeters;
- forming a portion of said multilayer tape to a desired shape;
- stacking a plurality of said multilayer tape portions to form a stacked array;
- heating said stacked array within a furnace the temperature of which is increased at a preselected rate up to about 500 degrees centigrade to remove both said binder and said plasticizer, and also to remove said oriented fibers from said cathode tape and said anode tape thereby to form a plurality of passageways therewithin;
- and
- sintering said stacked array to densify said cathode, electrolyte, anode, and interconnect and form the monolithic solid oxide fuel cell.
A multilayer tape for use in the construction of a solid oxide fuel cell comprising:
- a cathode layer;
- an electrolyte layer;
- an anode layer;
- an interconnect layer, said cathode, electrolyte, anode, and interconnect layers each including respective ceramic powders, respective binders, and respective plasticizers;
- and
- a plurality of oriented organic fibers within said cathode layer and said anode layer, said fibers extending a substantial length within said multilayer tape.
A monolithic green state ceramic assembly comprising:
- a core having a plurality of multilayer cells each cell having a cathode layer, an electrolyte layer, an anode layer and an interconnect layer, said plurality of multilayer cells stacked together to form a stacked array, said stacked array being substantially free of voids and open spaces;
- a first pair of manifolds located at opposite ends of said core;
- a second pair of manifolds located at opposite ends of said core;
- a first plurality of oriented organic fibers disposed within said anode layers or said cells, said first fibers extending from one of said pair of first manifolds through said core to the other of said first manifolds.
Dependencies are inferred from the claim text.