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Gas diffusion layer preconditioning for improving performance and operational stability of PEM fuel cells

一种气体扩散层、燃料电池的技术，应用在燃料电池、电气元件、电池电极等方向，能够解决体积大、不能用汽车应用、电池堆延迟等问题

Inactive Publication Date: 2007-07-11
GM GLOBAL TECH OPERATIONS LLC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Bladder compression devices can be used to maintain constant stack compression; however, such devices are bulky and cannot be used in automotive applications
Recompression of the stack as part of the standard maintenance condition can reset the condition; however, this process requires removal of the fuel cell stack from the system and does not improve the inhomogeneous nature of the intrusion tank
Finally, staged compression assumes that the compressive load will be increased in several steps in these steps as the stack operates for several hours until the compressive pressure reaches the nominal value; however, although further loss of compression is prevented and the problem of gas diffusion layer intrusion is partially resolved , but still create unacceptable delays in the battery stack placed in the system

Method used

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  • Gas diffusion layer preconditioning for improving performance and operational stability of PEM fuel cells
  • Gas diffusion layer preconditioning for improving performance and operational stability of PEM fuel cells
  • Gas diffusion layer preconditioning for improving performance and operational stability of PEM fuel cells

Examples

Experimental program
Comparison scheme
Effect test

example I

[0040] A gas diffusion layer material consisting of carbon fiber paper with an initial compressed thickness of approximately 230 microns was selected. It was determined that this material used as a gas diffusion layer within a PEM fuel cell (i.e. in situ) has acquired a compression set after about 20 hours of stack operation such that the compressive thickness changes under stack compressive loads. into 165 microns.

[0041] According to the method of the present invention, the same GDL material is preconditioned by being compressed (i.e. compression loaded) outside the fuel cell and before its assembly (i.e. externally), wherein the GDL material is subjected to a pressure of 2.1 MPa2 hours, then fully unzip and unload. The gas diffusion layer material thus acquires compression set such that the compressed thickness becomes 195 microns before use in a fuel cell stack. The pretreated gas diffusion layer material was then used as a gas diffusion layer in a PEM fuel cell, where...

example II

[0045] The pretreatment of the gas diffusion layer for a fuel cell constructed by precompression in a manner similar to that mentioned in Example 1 was carried out using a batch process. A set of 100 sheets of gas diffusion layer material was pre-cut to predetermined dimensions and stacked in stacks, with each gas diffusion layer sheet separated from adjacent sheets by approximately 250 micron thick plastic spacers. The stack was then placed in a compression apparatus (see Figures 10A to 10C) and the same pressure of 2.1 MPa was applied in order to compress all the sheets simultaneously, but this time for research purposes, for a duration of 3 hours.

[0046] The gas diffusion layer acquires compression set over time so that the actual compressive load also decreases over time. Therefore, every 10 to 20 minutes, check and adjust the compression force as shown in Figure 12, see F 1 to F 10 , to the initial compressive load value. After 2 hours of application of the compressi...

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Abstract

A method for reducing the compression set of GDL during the fuel cell operation and a method for reducing the intrusion of the GDL into flow-field channels, both achieved by pre-compression preconditioning the GDL before placing it into the fuel cell. This preconditioning is performed in order to reduce the loss of compression during the life of the stack and the mal-distribution of reactant gases, and ultimately achieve the benefits of higher power output and more stable performance.

Description

technical field [0001] The present invention relates to PEM fuel cells and, more particularly, to methods of improving the performance of GDL diffusion media by precompressing the GDL diffusion media. Background technique [0002] A fuel cell is an electrochemical energy conversion device. A fuel cell converts energy from the chemical reaction of a fuel and an oxidant into electricity. Fuel cells have been proposed for stationary applications such as power plants as well as smaller portable applications such as electric on-board power plants that will replace internal combustion engines in automobiles. The term "fuel cell" is generally used to denote a single cell or a plurality of cells, often arranged in series, also known as a stack. [0003] In a proton exchange membrane (PEM) fuel cell, hydrogen or a hydrogen-containing gas is supplied as a fuel to an anode of the fuel cell, and oxygen or an oxygen-containing gas such as air is supplied to a cathode of the fuel cell a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M8/00H01M4/88
CPCH01M8/0234Y02E60/50
Inventor P·A·拉帕波尔特赖业宏
Owner GM GLOBAL TECH OPERATIONS LLC
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