FABRICATION PROCESS FOR PRODUCTION OF SOFC-MEA WITH A PORE ARRAY ANODE STRUCTURE FOR IMPROVING OUTPUT POWER DENSITY

摘要

A fabrication process for production of planar type solid oxide fuel cell with high electrical conductivity and low fuel gas impedance is disclosed. It is a tape casting to produce an anode substrate furnished with a pore array structure on one or plurality of layers of the anode green tape on the utmost outside of the anode. It is to implement the process of solid oxide fuel cell membrane electrode assembly (SOFC-MEA) with precision abrasion to remove nickel depleted layer on the anode surface to complete the production of a unit cell. The fabrication of anode with pore array structure provides a good conduction effect for fuel gas and the solid oxide fuel cell with this treatment has features of high electrical conductivity and low fuel gas impedance to improve the performance of SOFC unit cell.

主权项

1. A fabrication process for production of a planar type solid oxide fuel cell membrane electrode assembly with pore array anode structure, comprising the steps of:
Step 1: producing an anode substrate for MEA by tape casting to produce thin strip anode green tapes; Step 2: providing a pore array structure having each pore with specified size of diameter and spacing between pores on the surface of the anode green tape, laminating multiple layers of the anode green tape that include perforated and non-perforated anode green tape through heat lamination and equalized water pressure lamination process to produce an anode supported substrate of green tapes having thickness between 300 μm and 800 μm; Step 3: conducting sintering on the anode supported substrate of green tapes at temperature about 1250° C. for 4 hours with temperature increment/decrement rate less than 3° C./min to obtain a first stage SOFC anode supported substrate; Step 4: conducting surface abrasion and polishing for the SOFC anode supported substrate, firstly, using a coarse sand paper to perform a surface pre-abrasion and polishing, followed by using a finer sand paper to produce a flat and smooth surface of the anode supported substrate; Step 5: building an electrolyte electrode by spin coating to produce a SOFC half cell with thickness less than 10 μm on the flat and smooth surface of the anode supported substrate, conducting sintering between 1200° C. and 1600° C. for more than 6 hours with temperature increment/decrement rate less than 3° C./min to obtain a first stage ceramic half cell, and using SEM to analyze the microstructure of the half cell to assure good adhesion between the anode electrode and electrolyte and that the electrolyte layer is open pore free, if open pores are still existing in the electrolyte layer, fixing the open pores with spin coating or sintering at temperature about 1350° C. for more than 6 hours to obtain a open pore free and fully dense electrolyte, Step 6: building a porous cathode layer of LSM material onto the electrolyte layer by screen printing, followed by sintering at about 1200° C. for 3 hours with a sintering temperature rate less than 3° C./min to complete the production of a unit cell of SOFC-MEA.