CN112993323B

CN112993323B - Proton exchange membrane fuel cell with self-drainage function

Info

Publication number: CN112993323B
Application number: CN201911287119.0A
Authority: CN
Inventors: 耿江涛; 陈中岩; 真新; 邵志刚
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2019-12-14
Filing date: 2019-12-14
Publication date: 2022-05-10
Anticipated expiration: 2039-12-14
Also published as: CN112993323A

Abstract

The invention provides a proton exchange membrane fuel cell with self-draining function, at least one side of anode side or cathode side of the cell has parallel-series structure, and the cell is arranged in a mode that membrane electrode is parallel to ground, and the upper part of the cell is used for air intake and the lower part of the cell is used for air exhaust. When the proton exchange membrane fuel cell operates, liquid water in the cell can be automatically discharged out of the cell under the action of air flow and gravity. The fuel cell has simple structure, does not need auxiliary components such as an external water separator, an air pump and the like, and can effectively simplify the components of the fuel cell system, thereby being beneficial to reducing the quality, the volume and the power consumption of an auxiliary system and improving the reliability.

Description

Proton exchange membrane fuel cell with self-drainage function

Technical Field

The invention relates to the field of fuel cells, in particular to a proton exchange membrane fuel cell with a self-drainage function.

Background

A fuel cell is an electrochemical conversion device that converts chemical energy in a fuel and an oxidant into electrical energy. The proton exchange membrane fuel cell is one of fuel cells, generally uses hydrogen as fuel, uses air or oxygen as oxidant, has the characteristics of high starting speed, low working temperature, high working efficiency, environmental friendliness and the like, can be applied to the fields of electric automobiles, dispersed power stations, unmanned planes, underwater submarines and the like, and is one of the research hotspots at home and abroad in recent years.

For a proton exchange membrane fuel cell, limited by the space and mass load of the mounting environment, the higher the indexes such as specific mass/power and efficiency, the better, which requires reducing the volume, mass and power consumption of the fuel cell and the auxiliary system as much as possible.

Currently, the common proton exchange membrane fuel cell has two structures: one is a parallel structure, namely a parallel air inlet mode is adopted, the battery of the structure usually needs a gas circulating pump or a jet pump and the like, the water in the battery is taken out by utilizing the gas circulation, and a gas-water separator is needed to be arranged for water separation; the other structure is a parallel-series structure, the battery is divided into a plurality of sections, the reaction gas is gradually consumed in the battery, and the unreacted gas is accumulated to the last section of the battery and then discharged.

Whether the batteries are in parallel connection or in parallel and series connection, external auxiliary components such as a pump/ejector, a gas-liquid separator, a pipeline or a one-way valve and the like are required; for cells in a parallel-series configuration, the gas supply or discharge also requires the installation of corresponding gas guides. These auxiliary components increase the overall volume, weight, and power consumption of the fuel cell system, on the one hand, and also increase the complexity and reliability of the system, on the other hand.

Disclosure of Invention

In view of the above-mentioned technical problems of the prior art, a proton exchange membrane fuel cell with self-draining function is provided, which discharges water in the cell by means of air flow and gravity.

The technical means adopted by the invention are as follows:

a proton exchange membrane fuel cell with self-draining function, at least one side of the anode side and the cathode side of the fuel cell is in parallel-series structure, thereby dividing the cell into a plurality of cell groups; and in operation, the fuel cell is arranged with the membrane electrode or bipolar plate parallel to the ground.

Further, the plurality of battery packs are arranged from top to bottom according to the number of the single batteries contained in each battery pack, wherein the battery pack containing the large number of the single batteries is arranged at the top.

Further, the fuel cell has one side of a parallel-serial structure, and the reactants are gaseous and arranged to be supplied at an upper portion and discharged at a lower portion.

Further, the parallel-serial structure includes a membrane electrode or a bipolar plate which is impermeable to gas to change a flow direction.

Further, part of the common channels of the membrane electrode or bipolar plate are closed.

Compared with the prior art, the invention has the following advantages:

the invention adopts one side of the fuel cell with a parallel-series structure, does not need to be externally connected with auxiliary components such as an air pump/ejector, a water separator, a guiding device, a pipeline, a valve and the like, and can reduce the volume, the weight and the power consumption brought by the auxiliary components, thereby being beneficial to improving the efficiency, the specific energy/the power density of the fuel cell.

The invention simplifies the working process of the system, and the reduction of the number of components is beneficial to reducing the overall cost and improving the reliability.

In conclusion, the invention discharges water in the cell by depending on the action of air flow and gravity, and can be widely popularized in the field of fuel cells.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of the hydrogen side configuration of the parallel-series fuel cell of the present invention.

FIG. 2 is a schematic diagram of the oxygen side structure of the parallel-series fuel cell of the present invention.

Fig. 3 is a schematic plan view of a general membrane electrode.

FIG. 4 is a schematic plan view of a membrane electrode in the example.

Fig. 5 shows the results of the fuel cell stability test in the example.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus that are known by one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. Any specific values in all examples shown and discussed herein are to be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the directions or positional relationships indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the directions or positional relationships shown in the drawings for the convenience of description and simplicity of description, and that these directional terms, unless otherwise specified, do not indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … … surface," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The invention provides a proton exchange membrane fuel cell with a self-draining function, at least one side of an anode side and a cathode side of the fuel cell is of a parallel-series structure, so that the cell is divided into a plurality of cell groups; and in operation, the fuel cell is arranged with the membrane electrode or bipolar plate parallel to the ground. Further, the plurality of battery packs are arranged from top to bottom according to the number of the single batteries contained in each battery pack, wherein the battery pack containing the single batteries with the large number is arranged on the top, and if the number of the single batteries of the two battery packs is the same, the battery pack can be arranged on the top. Further, the fuel cell has one side of a parallel-serial structure, and the reactants are gaseous and arranged to be supplied at an upper portion and discharged at a lower portion. Further, the parallel-serial structure comprises a membrane electrode or a bipolar plate which can not be penetrated by gas so as to change the flow direction, and part of the common pore channels of the membrane electrode or the bipolar plate are closed.

The technical solution of the present invention is further explained by the following specific application examples.

As shown in FIG. 1-2, the fuel cell is a hydrogen-oxygen proton exchange membrane fuel cell, the reactant gases are hydrogen and oxygen, the cell is composed of 16 single cells, and the effective area of a single cell Membrane Electrode (MEA) is 260cm²The hydrogen side and the oxygen side are both in parallel-series structure, and as can be seen from fig. 1 and fig. 2, the cell is divided into three sections no matter on the hydrogen side or on the oxygen side, and as a preferred embodiment, the number of the first to the third sub-cells is respectively: sections 9, 5 and 2. In addition, the battery is placed in a mode that the MEA is parallel to the ground, the oxyhydrogen air inlets are all positioned at the upper end, and the outlets are all positioned at the lower end.

In the embodiment, the parallel-serial structure of the hydrogen-oxygen sides of the 16 batteries is realized by the special design of MEA. Fig. 3 is a schematic plan view of a conventional MEA having 6 holes as common channels: 2 hydrogen, 2 oxygen and 2 water, and the MEA is used in each single cell with the internal gas circuits of each sub-cell connected in parallel. In order to realize the diversion of the air flow at the junctions of each sub-cell, the membrane electrode is optimized in this embodiment, and as shown in fig. 4, the MEA has 4 holes: 1 hydrogen, 1 oxygen, 2 water, one hole less each of hydrogen and oxygen. When the gas flows to the closed channel of this type of MEA (the closed channel position is shown as an "X" in FIG. 4), the gas can only flow along the plane direction of the MEA due to the non-penetration, thereby achieving the purpose of gas baffling.

When the fuel cell operates, hydrogen and oxygen enter from the upper end of the cell, firstly enter the first section of sub-cell, horizontally flow in the first section of sub-cell, and liquid water in the cell enters the second section of sub-cell under the action of airflow driving and gravity; the gas in the second section of the sub-battery still flows horizontally, and liquid water is brought into the third section under the action of the gas flow and gravity; and the gas in the third section of sub-battery takes the liquid water out of the battery through the action of horizontal flow and gravity.

Fig. 5 shows the measured stability of the 16 pem fuel cells in this example, wherein the cumulative operating time of the experiment is about 1327 hours. Under testThe output current of the battery is 130A (500 mA/cm) in the process²) The output voltage is 11-12V, and the power reaches 1.5-1.6 kW. The cell performance decayed by about 2.2% before and after the entire test. As can be seen from fig. 5, the fuel cell using this structure can achieve stable operation without the need for auxiliary components such as a gas circulation pump/ejector, a water separator, a pipeline, and a valve, thereby facilitating simplification of the system process, and improvement of specific energy/power density, efficiency, and overall reliability of the system.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A proton exchange membrane fuel cell with self-draining function is characterized in that at least one side of an anode side and a cathode side of the fuel cell is in a parallel-series structure, so that the cell is divided into a plurality of cell groups; when the fuel cell works, the membrane electrode or the bipolar plate is arranged to be parallel to the ground;

the membrane electrode comprises a through hole for hydrogen to flow through, a through hole for oxygen to flow through and two through holes for water to flow through, and when the gas flows to the membrane electrode, the gas can only flow along the plane direction of the MEA, so that gas baffling is realized;

the plurality of battery packs are arranged from top to bottom according to the number of single batteries contained in each battery pack, wherein the battery pack containing a large number of single batteries is arranged on the top;

when the fuel cell operates, hydrogen and oxygen firstly enter the upper layer cell and then horizontally flow, and liquid water in the battery is driven to enter the lower layer cell under the action of air flow and gravity.

2. The pem fuel cell of claim 1 wherein said fuel cell has one side of a parallel-series configuration, reactants are gaseous and are arranged to be inlet at the upper portion and exhaust at the lower portion.

3. The pem fuel cell of claim 1 wherein said parallel-series configuration comprises a membrane electrode or bipolar plate that is impermeable to gases and thus changes flow direction.