CN207557294U - The test fixture of membrane electrode - Google Patents

Abstract

The utility model provides a test fixture for a membrane electrode, which comprises oppositely arranged positive and negative plates, and a gas flow field is arranged on the corresponding surfaces of the positive and negative plates; There are air inlet, air outlet and power interface; the air inlet and the air outlet communicate with the flow field; and the connection structure for fixing the positive and negative plates. The utility model also provides a testing method of the membrane electrode. The utility model is convenient to assemble and disassemble, and the resistance value of the positive and negative plates made of stainless steel is small, and the test error of the membrane electrode is also reduced.

Description

Membrane electrode test fixture

technical field

The utility model relates to the field of performance testing of fuel cells, in particular to a test fixture and a test method of a membrane electrode.

Background technique

As a new type of clean power generation device, the proton exchange membrane fuel cell (PEMFC) can directly convert the chemical energy stored in the fuel into electrical energy for people's production and daily use, and has high energy efficiency, fast start-up, zero emissions, low Noise, can work continuously for a long time and so on. PEMFC is assembled by a group of single cells in series to obtain the required output power. Today, when energy resources are scarce and environmental problems are frequent, environmentally friendly new energy sources such as fuel cells have attracted widespread attention. Among them, the test of the membrane electrode of the fuel cell is particularly important. The traditional membrane electrode test fixture and test method have a roughly similar structure, mainly composed of an end plate, a current collector plate and a bipolar plate. During the installation of the membrane electrode, the bipolar plate and the current collector plate need to be installed on both sides in sequence. Between the end plates; the disassembly and assembly are complicated. In addition, the contact area increases due to the superposition of multiple layers of materials, which also increases the contact resistance of the test fixture and increases the error of the test results.

Utility model content

In order to solve this technical problem, the utility model provides a test fixture and a test method of a membrane electrode, which are used to solve the problems of complex disassembly and assembly of the test fixture and test method of the membrane electrode in the prior art, and large errors in test results.

In order to solve the above problems, the utility model provides a test fixture for membrane electrodes, comprising: positive and negative plates oppositely arranged, and a gas flow field is arranged on the corresponding surfaces of the positive and negative plates; Air intake holes, air outlet holes and power supply interfaces are provided on the side of the plate; the air inlet holes and the air outlet holes communicate with the gas flow field; and the connection structure for fixing the positive and negative plates.

The utility model is composed of two positive and negative plates fixedly, and the end plate, the collector plate and the bipolar plate are fused together, and the gas flow field is installed on the opposite surface of the positive and negative plates, and the positive and negative plates The air inlet, air outlet and power interface are set on the side of the machine. The air inlet and outlet are connected with the gas flow field. The air and hydrogen enter the gas flow field through the inlet hole and undergo chemical changes to generate electric energy. The fixture structure is simple and easy to disassemble. It is convenient, and the simple structure of the utility model reduces the resistance of the test fixture and reduces the influence on the test result of the membrane electrode.

A further improvement of the present invention is that the positive and negative plates are provided with a plurality of through holes that communicate with each other, and the positive and negative plates are fixed by bolts and nuts to form the connection structure.

A further improvement of the utility model is that the air inlet and the air outlet are arranged on the sides of the positive and negative plates, and the central axis of the power interface is connected to the central axis of the air inlet and the air outlet. perpendicular to each other.

The utility model also provides a method for testing a membrane electrode, comprising the following steps:

S11: Provide a test fixture for a membrane electrode, comprising: oppositely arranged positive and negative plates, a gas flow field is provided on the corresponding surfaces of the positive and negative plates; An air inlet, an air outlet, and a power interface; the air inlet and the air outlet communicate with the gas flow field; and a connection structure for fixing the positive and negative plates. And measure the resistance of the positive and negative plates; S12: provide gaskets, membrane electrodes, gas inlet and outlet joints and electrode joints, and assemble to form a single cell; S13: provide a gas leakage measurement device to test the airtightness of the single cell To ensure safety; S14: provide a proton exchange membrane fuel cell test system connected to the single cell, and measure the open circuit voltage of the single cell.

A further improvement of the utility model is that the resistance of the positive and negative plates is measured using formula (1)

Wherein, ρ represents the resistivity, L represents the length of the positive and negative plates, and S represents the surface area.

A further improvement of the present invention is that the step of assembling the single cell includes the following steps: S121: Cover the gas flow field with the sealing gasket; S122: Sandwich the membrane electrode in the gasket, use Fasten the positive and negative plates with bolts and nuts; S123: install the gas inlet and outlet connectors at the air inlet and outlet holes, and install the electrode connectors at the power interface.

The further improvement of the utility model is that a torque meter is provided to set the torque of each bolt and nut to an equivalent value.

A further improvement of the utility model is that the air leakage measuring device includes an air compressor and a rotor meter, and testing the air tightness of the single battery includes the following steps:

S131: Install the vortex meter at the air inlet hole and the air outlet hole;

S132: Turn on the air compressor, and set the gas flow rate to flow into the single battery;

S133: The vortex meter measures the gas flow values at the gas port and the gas outlet, and calculates the gas leakage rate of the single cell according to formula (2).

A further improvement of the utility model is that measuring the open circuit voltage of the single battery comprises the following steps:

S141: Connect the gas inlet and outlet of the proton exchange membrane fuel cell testing system to the gas inlet and outlet connectors of the single cell, and set the test temperature;

S142: injecting nitrogen gas into the single cell to evacuate the air in the single cell;

S143: Provide an air compressor to feed air into the cells respectively;

S144: provide a multimeter, measure the open circuit voltage at both ends of the single battery, and turn off the air compressor.

A further improvement of the utility model is that the hydrogen gas is passed into the air inlet on the negative plate, and the air is passed into the air inlet on the positive plate.

Compared with the prior art, the utility model has the beneficial effects that the positive and negative plates are formed by fusing the end plates, current collector plates and bipolar plates of the prior art into one body, which is convenient for disassembly and assembly, and the positive and negative plates are The resistance value is small, and the test error of the membrane electrode will also be reduced.

Description of drawings

Fig. 1 is the schematic diagram of the test fixture of the membrane electrode of the present utility model;

FIG. 2 is a schematic diagram of a single battery of the present invention.

reference sign

1. Positive and negative electrode plates; 11. Gas flow field; 12. Air inlet hole; 13. Through hole; 14. Power interface; 15. Air outlet hole; 21. Bolt; 22. Nut; 4. Gasket, 5. Membrane electrode; 6. Gas inlet and outlet connectors; 7. Electrode connectors.

Detailed ways

The above and other technical features and advantages of the utility model are clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some embodiments of the utility model, rather than all embodiments.

The utility model provides a test fixture and a test method for a membrane electrode. Commonly used test fixtures are formed by stacking end plates, current collector plates, and bipolar plates, which are complex to disassemble and assemble, and also increase the contact resistance of the test fixture and increase the test error of the membrane electrode. The utility model fuses the end plate, the current collecting plate and the bipolar plate into one positive and negative plate, which is convenient for disassembly and assembly, and the resistance value is small, which reduces the error of the membrane electrode test. The test fixture and test method of the membrane electrode of the present invention will be described below with reference to the accompanying drawings.

Referring to Figures 1 and 2, the utility model is a test fixture for a membrane electrode, including positive and negative plates 1 and a connecting structure. Among them, the positive plate and the negative plate are arranged oppositely, and the installation gas flow field 11 is provided on the corresponding surface of the positive and negative plates, and the air inlet 12, the air outlet 15 and the power supply are all provided on the sides of the positive and negative plates. interface14. The air inlet hole 12 and the air outlet hole 15 extend to the inside of the positive and negative plates until they communicate with the gas flow field 11 . The connection structure fixedly connects the positive and negative plates 1 . Membrane electrodes are clamped in this test fixture by a series of components.

The positive and negative plates are made of stainless steel, which has the advantages of excellent electrical and thermal conductivity, good mechanical properties, good air tightness, easy processing and low cost. The structure of the flow field determines the flow state of reactants and products in the flow field, especially for large-area proton exchange membrane fuel cells, the flow field structure will directly affect the performance of the battery. The two sides of the positive and negative plates are respectively provided with reaction areas for air and hydrogen. The flow field design requires that the fuel and oxidant required for battery discharge can be evenly distributed to ensure uniform current density distribution, avoid local overheating, and enable the water generated by the reaction to be entrained by the flowing reaction gas and discharged smoothly. At present, the widely used flow field is mainly parallel groove flow field and serpentine flow field; the former can change the linear velocity of the reaction gas flowing through the flow field groove by changing the width ratio of the groove to the ridge and the length of the parallel groove. The liquid water is discharged from the battery, and the latter adjusts the linear velocity of the reactant gas flowing in the flow field by changing the width ratio of the groove to the ridge, the number of channels, and the total length of the serpentine groove to ensure that the liquid water is discharged from the battery. It is reported that the ratio of the width of the groove to the width of the ridge is controlled between 1: (1.2-2.0) in serpentine and parallel groove flow fields. Usually the width of the groove is about 1mm, and the width of the ridge should be between 1-2mm; the depth of the groove should be determined by the total length of the groove and the total pressure drop of the allowable reactant gas flowing through the flow field, and should generally be controlled at 0.5- Between 1.0mm.

The positive and negative plates 1 are provided with a plurality of through holes 13 penetrating through the positive and negative plates 1 , the connection structure is bolts 21 and nuts 22 , and the positive and negative plates 1 are connected and fixed through the through holes 13 . The air intake hole 12 and the air outlet hole 15 on the positive and negative pole plates 1 are arranged on the opposite sides of the positive and negative pole plates 1. In order to transport the reduced hydrogen ions to the electrodes, the central axis of the power supply interface 14 and the air intake The axes of the hole 12 and the outlet hole 15 are perpendicular.

The utility model also introduces a testing method of a membrane electrode, comprising the following steps:

(1) First, provide a measuring fixture as described above, measure the size of the fixture, and then calculate the resistance value R of the measuring fixture according to formula (1).

Among them, ρ represents the resistivity, L represents the length of the positive and negative plates, and S represents the surface area.

(2) Provide flow field 3, sealing gasket 4, membrane electrode 5, gas inlet and outlet connector 6 and electrode connector 7, and assemble to form a single cell, including the following steps:

(a) Install a gasket 4 on the gas flow field 11 on the positive and negative plates 1;

(b) Clamp the membrane electrode in the gasket 4 of the positive and negative plates 1, and then fix and tighten the positive and negative plates 1 with bolts and nuts. During this process, use a torque meter to set the torque of each bolt and nut to equal value.

(c) Finally, the gas inlet and outlet joints 6 are installed at the air inlet 12 and the air outlet 15 , and the electrode joint 7 is installed at the power interface 14 .

Wherein, the gas flow field includes a mesh flow field and a serpentine flow field, and the utility model is preferably a serpentine flow field.

(3) Next, in order to ensure the safety during the measurement, it is necessary to measure the airtightness of the single cell by using an air leakage measurement device. The air leakage measurement device includes an air compressor and a rotor meter, and the specific steps are as follows:

Install the vortex meter at the body inlet hole 12 and the air outlet hole 15. When all the inlet and outlet are connected, turn on the air compressor, set the gas flow rate to flow into the single battery, and record after the readings of each vortex flowmeter are basically stable. The data of each flowmeter, and then calculate the air leakage rate of the device according to the difference between the inlet and outlet flowmeters. The calculation formula is shown in (2).

(4) Finally, use the proton exchange membrane fuel cell test system to connect the single cell, and use a multimeter to measure the open circuit voltage of the single cell to obtain the performance of the membrane electrode 5 . Proceed as follows:

Connect the gas inlet and outlet of the assembled single cell to the gas inlet and outlet of the proton exchange membrane fuel cell test system in turn, and set the humidification temperature of the test system; open the nitrogen valve to feed nitrogen, and start timing at the same time, the ventilation time is 10 minutes, and wait for ventilation After the completion, close the nitrogen valve; open the air compressor valve to feed air into the air inlet on the positive plate, then open the hydrogen cylinder to feed hydrogen into the air inlet on the negative plate, set the flow ratio of hydrogen and air, and open the test system The hydrogen switch in the control panel; use a multimeter to test the open circuit voltage at both ends of the single battery, and record the data after the open circuit voltage is stable; after the test, first turn off the hydrogen and air switches in the control panel of the test system, and set the hydrogen and air electronic valve flow to 0 in turn , close the hydrogen cylinder valve and the air compressor valve, and remove the single battery.

The utility model is formed by fixing two positive and negative plates, and integrates the end plate, the current collecting plate and the bipolar plate into one body, and a gas flow field is provided on the opposite surfaces of the positive and negative plates, and between the positive and negative plates Air inlet, air outlet and power interface are set on the side, the inlet and outlet are connected with the gas flow field, the air and hydrogen enter the gas flow field through the inlet hole and chemically change to generate electric energy, the fixture structure is simple and easy to disassemble , and the simple structure of the utility model reduces the resistance of the test fixture and reduces the influence on the test result of the membrane electrode.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present utility model in detail. It should be understood that the above descriptions are only specific embodiments of the present utility model and are not intended to limit the utility model. scope of protection. In particular, for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (3)

1. A test fixture for a membrane electrode, characterized in that, comprising: Opposite positive and negative plates are provided with a gas flow field on the corresponding surfaces of the positive and negative plates; air inlets, air outlets and power ports are provided on the sides of the positive and negative plates; The air hole and the air outlet are connected with the gas flow field; and the connection structure for fixing the positive and negative plates. 2. The test fixture according to claim 1, characterized in that, the positive and negative plates are provided with a plurality of through holes that communicate with each other, and the positive and negative plates are fixed by bolts and nuts to form the connection structure. 3. The test fixture according to claim 1, wherein the air inlet and the air outlet are arranged on the sides of the positive and negative plates, and the central axis of the power interface is connected to the air inlet. perpendicular to the central axis of the air outlet.