Alignment method for preparing membrane electrode sealing border of fuel cell

Abstract

The invention relates to an alignment method for preparing a membrane electrode sealing border of a fuel cell. The membrane electrode sealing border is prepared by the following steps of: applying a negative electrode alignment mark to a negative electrode sealing border, and applying a positive electrode alignment mark to a positive electrode sealing border; judging the alignment deviation between the active area of the negative electrode sealing border and the active area of the positive electrode sealing border through human eyes identification or optical identification or CCD (charge coupled device) identification according to a pattern formed by the negative electrode alignment mark and the positive electrode alignment mark in the plane direction vertical to the sealing border; adjusting the relative positions of the negative electrode sealing border and the positive electrode sealing border according to the alignment deviation, and performing alignment coverage of the negative electrode sealing border, a polymer ion exchange membrane and the positive electrode sealing border in a certain precision range so that the active area of the prepared membrane electrode sealing border has relatively high alignment precision and the active area of the membrane electrode can be accurately controlled. The method is suitable for the alignment precision control in the batch production of the membrane electrode sealing border.

Description

field of invention [0001] The invention relates to a membrane electrode preparation technology of a polymer ion exchange membrane fuel cell, in particular to an alignment method for sealing frame active regions in the membrane electrode preparation process. Background of the invention [0002] Polymer ion-exchange membrane fuel cell (PEMFC) has the advantages of high power density, high energy conversion efficiency, low-temperature start-up, and environmental friendliness. Today's deterioration has become one of the hot spots of international high-tech competition. Membrane electrode (MEA) is the most critical component of polymer ion exchange membrane fuel cells, and the polymer ion exchange membrane plays a role in conducting protons, blocking electrons from directly forming a loop inside the battery, and blocking direct contact between hydrogen and oxygen / air ( That is, the role of sealing). However, due to the very thin thickness of the polymer ion exchange membrane, i...

AI Technical Summary

Problems solved by technology

[0012] (1) Affecting the processing of membrane electrodes

The gas diffusion layer needs to be laminated on the basis of the position of the sealing frame. The alignment accuracy of the sealing frame is not high, which will affect the laminating position of the gas diffusion layer. damage or even breakage;

[0013] (2) Reduce the power density and reliability of the fuel cell stack

In order to improve the adaptability to poor precision membrane electrodes and align the components, the size of each component of the stack needs to be made larger accordingly, which reduces the power density of the stack; at the same time, the deviation of the assembly size will bring Many problems, such as flow channel blockage, polymer ion exchange membrane damage, gas leakage at the inlet and outlet, and gas leakage, can easily lead to the mixing of hydrogen and oxygen, and there is even a risk of explosion in the presence of catalysts, which greatly reduces the reliability of the fuel cell stack. sex;

[0014] (3) Reduce the durability of the fuel cell

Poor precision results in incorrect positional relationship of the various parts of the membrane electrode, which causes the polymer ion exchange membrane to be damaged after a short period of operation of the membrane electrode, which leads to the failure of the fuel cell and reduces the life of the fuel cell;

[0015] (4) A waste of resources

The alignment accuracy of the membrane electrode sealing frame is not high, which affects the matching relationship of the various parts of the membrane electrode, so that some catalysts are not in the correct position, so they cannot perform their due functions, resulting in waste of expensive precious metal catalysts, and at the same time causing The waste of the equally expensive polymer ion exchange membrane is eliminated;

[0016] (5) Causes a reduction in the output power of the fuel cell

The misalignment of the cathode and anode sealing frame of the membrane electrode will cause the catalyst in the misaligned area to fail to perform its proper electrocatalytic function and reduce the output power. According to calculations, the output power will be correspondingly reduced for every 1% reduction in the alignment accuracy of the membrane electrode sealing frame. reduced by 4%

[0017] Patents [CN200810197098.9] and [CN201010125455.8] proposed a feasible process for alignment lamination of membrane electrode sealing frame, but neither explained how to effectively improve and ensure the alignment accuracy of membrane electrode sealing frame lamination

However, the detection and alignment of the active area of ​​the sealing frame has many insurmountable difficulties in the actual preparation process of the fuel cell sealing frame.

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