Fuel cell stack and fuel cell module

Abstract

A fuel cell stack includes at least one fuel cell unit and a number of interconnects defining at least two openings and including at least one flow field for flowing a reagent. Each opening defines a respective fuel manifold, including at least one each of intake and exhaust fuel manifolds. The fuel cell unit includes an anode, a cathode, and an electrolyte disposed therebetween. The anode is adjacent to and in both electrical connection and fluid communication with one of the interconnects, which has a flow field that guides a fuel flow between the intake and exhaust fuel manifolds. The cathode is adjacent to and in both electrical connection and fluid communication with another interconnect with a flow field that guides an oxidant flow. The fuel cell stack includes a perimeter isolation seal and at least two interior isolation seals for sealing the electrolyte to the respective interconnects.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates generally to fuel cell stacks and modules for power generation, and more particularly, to fuel cell stacks and modules with segregated reactant streams. [0002] Fuel cells, for example solid oxide fuel cells (SOFCs), are energy conversion devices that produce electricity by electrochemically combining a fuel and an oxidant across an ionic conducting layer. The fuel cell operating temperatures depend on the material forming the ionic conducting layer. Desirably, power generation systems incorporating high-temperature fuel cells have the potential for higher efficiencies and power outputs. Exemplary high-temperature fuel cells have operating temperatures above about 600° C., and exemplary SOFCs operate in a range of about 800 to about 1000 degrees Celsius. [0003] A typical fuel cell operates at a potential of less than about one (1) Volt. To achieve sufficient voltages for power generation applications, a number of individual fue...

AI Technical Summary

Benefits of technology

The design effectively segregates reactant streams, enhances seal performance, and allows for the integration of redundant current paths, improving the efficiency and reliability of high-temperature fuel cell stacks by minimizing seal failure and maintaining separation across thermal cycles.

Problems solved by technology

Elastomer seals cannot withstand the operating temperatures of high-temperature fuel cells, and consequently other materials, such as glass ceramics, must be used to form the seals.

However, seal performance remains problematic for high temperature fuel cells, in particular for designs requiring sealing of cell edges or corners or for other joint designs that require maintaining a gap of a certain size during thermal expansion and contraction cycles.

Images