Chromium Getter for Fuel Cell Interconnect Poisoning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High temperature fuel cells, such as solid oxide fuel cells, suffer from chromium poisoning due to chromium evaporation from interconnects and balance of plant components contaminating the oxidizing gas stream, which reduces the operating life of the fuel cell system.
Innovation Solution
Incorporating a chromium getter in the incoming oxidizing gas flow path, typically coated on a substrate with gas flow passages, to capture and deposit chromium from the gas stream, preventing it from reaching the cathode electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If chromium-containing interconnects are used in high temperature fuel cells, then electrical conductivity and structural integrity are improved, but chromium evaporation contaminates the oxidizing gas stream and poisons the cathode electrode
Solution Approach 1:
A chromium getter material is introduced as an intermediary component between the chromium-containing interconnect and the cathode electrode. This getter material captures chromium vapors through preferential adsorption or chemical reaction, preventing chromium from reaching and poisoning the cathode while allowing the interconnect to maintain its chromium-containing composition for structural integrity
Solution Approach 2:
The harmful chromium vapor is extracted from the oxidizing gas stream by the chromium getter material. The getter selectively removes chromium species from the gas phase through surface adsorption or chemical trapping mechanisms, concentrating the chromium in the getter rather than allowing it to deposit on the cathode electrode
2Productivity
If the fuel cell operates at high temperature (750-950°C), then energy conversion efficiency is improved, but chromium evaporation rate increases and accelerates cathode poisoning
Solution Approach 1:
The chromium getter acts as a protective intermediary that enables the fuel cell to operate at high temperatures for improved efficiency while preventing the temperature-accelerated chromium evaporation from reaching the cathode. The getter material is designed to be stable and effective across the full operating temperature range
Solution Approach 2:
The chromium getter is positioned upstream in the oxidizing gas flow path to preemptively capture chromium vapors before they can reach the cathode electrode. This preliminary action occurs continuously during operation, preventing cathode poisoning before it can occur
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively prevents chromium poisoning by capturing chromium vapors before they reach the cathode, thereby extending the operational life and maintaining the efficiency of the fuel cell system.
Implementation Method 1
a chromium getter including a substrate having at least one gas flow passage in, on or through the substrate, and a chromium-getter material coated on the substrate inside the at least one gas flow passage
Data Source
AI summary
A fuel cell assembly includes a fuel cell stack including a plurality of fuel cells, an incoming oxidizing gas flow path configured to deliver an oxidizing gas to the plurality of fuel cells, and a chromium-getter material located in the incoming oxidizing flow path. A fuel cell includes an electrolyte, a cathode electrode on a first side of the electrolyte, an anode electrode on a second side of the electrolyte, and a chromium-getter material on the cathode electrode.