CCS and Power Systems

Advanced Energy Systems - Solid Oxide Fuel Cells

Solid Oxide Fuel Cell Cathode Enhancement Through a Vacuum-assisted Infiltration

Performer: Materials & Systems Research Inc.

Project No: SC0006374

Project Description

Currently, composite cathodes are formed by directly mixing the active cathode material with electrolyte at different ratios, followed by deposition and sintering into graded functional layers. Since the effectiveness of the composite cathode (the cathode is the electrode at which oxygen ions are removed from the air supply) greatly depends on the composite microstructure and intrinsic material properties, solid oxide fuel cell (SOFC) cell fabrication processes must be engineered to ensure the electrode micro-structural characteristics have continuous phases, open and continuous pores, well-linked (sintered) cathode particles, and a long triple phase boundary.

This project will develop a cost-effective vacuum-pressure infiltration thermal treatment (VPIT) technique to improve SOFC cathode performance and longevity through the impregnation of an inexpensive electro-catalyst precursor into a cathode backbone. Upon calcination (a thermal treatment process) at reduced temperatures, a thin but continuous network of nano-sized catalysts is formed, covering the cathode backbone with enlarged catalytic surface area and heterogeneous microstructure. This enhances both the oxygen exchange rate and oxygen ion transport rate on the cathode surface. The reduced temperature calcination will greatly improve the stability of the cathode.

In Phase I, the vacuum-assisted infiltration apparatus and the infiltration protocol will be developed and validated using two sizes of cell test apparatus: button cells and short stacks with 100 square centimeters per-cell active areas. Catalyst distribution and morphology will be investigated via advanced X-ray diffraction and radiographic techniques. Phase II will support manufacturing scale-up to meet cost goals, and will include kilowatt-scale stack validation.

Project Details