Fuel Cell Stack Startup Voltage Control for Catalyst Protection
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Solution Overview
Problem
Catalyst deterioration in fuel cells due to high output voltage during power generation, leading to elution and coarsening of platinum-based particles.
Innovation Solution
Implementing a low-voltage operation before normal operation in a fuel cell system, where the output voltage of fuel cells is maintained at a lower level to form an oxide film on the catalyst surface, thereby suppressing deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the output voltage of fuel cells is increased to improve power generation efficiency, then the power generation efficiency is improved, but elution and coarsening of the catalyst occurs readily leading to catalyst deterioration
Solution Approach 1:
The control device executes a low-voltage operation before the normal operation to preliminarily form an oxide film on the catalyst surface. This preliminary action of forming the protective oxide film at lower voltage prevents catalyst deterioration during subsequent high-voltage power generation operations, thereby resolving the contradiction between power generation efficiency and catalyst durability
2Reliability
If the output voltage of fuel cells is maintained at a low level to form oxide film on catalyst, then catalyst deterioration is suppressed, but power generation efficiency is reduced
Solution Approach 1:
The power generation operation is segmented into two distinct phases: a low-voltage operation phase for oxide film formation and a normal high-voltage operation phase for efficient power generation. This segmentation allows the system to achieve catalyst protection during the low-voltage phase and then maintain high power generation efficiency during the normal operation phase, resolving the contradiction between reliability and productivity
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
The oxide film formed on the catalyst surface prevents elution and coarsening, maintaining catalyst integrity even at higher output voltages in subsequent normal operations.
Implementation Method 1
a fuel cell stack 10 in which a plurality of fuel cells 12 is disposed, being stacked
Implementation Method 2
a battery 40 that is electrically connected to the fuel cell stack 10 and that performs charging of power generated by the fuel cell stack 10
Data Source
AI summary
The fuel cell system includes a fuel cell stack in which a plurality of fuel cells is stacked and arranged, a battery electrically connected to the fuel cell stack and charging electric power generated by the fuel cell stack, and a control device that controls power generation by the fuel cell stack. The control device is configured to execute a low-voltage operation prior to transition to a normal operation, when the fuel cell system is activated. In the low-voltage operation, the power generation by the fuel cell stack is controlled so that the output voltage of the fuel cell is maintained at or below the first voltage value, and in the normal operation, the power generation by the fuel cell stack is controlled so that the output voltage of the fuel cell is maintained at or above the second voltage value higher than the first voltage value.