Novel air-cooled fuel cell structure

Abstract

The invention provides a novel air-cooled fuel cell structure, belongs to the technical field of new energy batteries, aims to solve the problem that the performance of a fuel cell is reduced when the power is high, and comprises two end plates, collector plates are arranged on the inner sides of the end plates, a cell unit is arranged between the two collector plates, and the cell unit is composed of a plurality of bipolar plates and membrane electrodes. A membrane electrode is arranged between every two adjacent bipolar plates, a plurality of air channels communicated with the membrane electrodes are formed in one side of each bipolar plate, and partition plates are arranged in the air channels.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy batteries, and more specifically, particularly relates to a novel air-cooled fuel cell structure. Background Art

[0002] A fuel cell is a device that directly converts chemical energy stored in fuel and oxidant into electrical energy. Among them, a proton exchange membrane hydrogen fuel cell (PEMFC) is a power generation device that converts the chemical energy of hydrogen and oxygen into electrical energy. It has the advantages of being clean, efficient, and low noise, and can be widely used in electric vehicles, drones, portable power supplies, etc. According to the heat dissipation method, proton exchange membrane hydrogen fuel cells (hereinafter referred to as hydrogen fuel cells) can be mainly divided into two types: liquid-cooled and air-cooled. Among them, air-cooled hydrogen fuel cells use ambient air as a cooling medium, and use a fan to drive the air to flow through the cooling channel. For air-cooled hydrogen fuel cells, ambient air is not only a cooling medium, but also a source of reactant oxygen. Therefore, in order to simplify the battery structure, the cooling air and reaction air supply channels of air-cooled hydrogen fuel cells are usually overlapped or parallel. The ambient air flows through the cathode channel driven by the fan, on the one hand, providing the battery with the oxygen required for the reaction, and on the other hand, taking away the heat generated by the battery reaction.

[0003] Air-cooled hydrogen fuel cells are usually stacked with membrane electrodes, bipolar plates, current collectors, end plates and sealing components. Currently, there are two main types of bipolar plates: graphite bipolar plates made of graphite and metal bipolar plates made of metal. In addition to serving as gas channels, they also play the role of conducting electricity and heat. Most of the heat generated by the chemical reaction in the membrane electrode is conducted away by the bipolar plates and eventually taken away by the cooling air to prevent the battery temperature from being too high.

[0004] For graphite bipolar plates, the supply channels for cooling air and reaction air completely overlap. For metal bipolar plates, the cathode cavity structure makes the cooling air and reaction air channels initially separated and parallel to each other, but because of the shared fan, the cooling air and reaction air flow rates are equivalent. Under high power conditions, the demand for cooling air is more than ten times or even dozens of times the demand for reaction air. In order to ensure the heat dissipation effect of the battery, the fan is mainly adjusted according to the demand for cooling air, which also causes a serious oversupply of reaction air. Excessive reaction air flow will cause water loss and imbalance in water management in the membrane electrode, ultimately leading to a decline in battery performance and even a decrease in operating life. This is a technical problem currently faced by air-cooled hydrogen fuel cells.

[0005] Therefore, in view of this, the existing structure and deficiencies are studied and improved, and a new air-cooled fuel cell structure is provided, in order to achieve a more practical purpose. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a novel air-cooled fuel cell structure to solve the problem of decreased battery performance when the fuel cell is at high power.

[0007] The purpose and effect of a novel air-cooled fuel cell structure of the present invention are achieved by the following specific technical means:

[0008] A novel air-cooled fuel cell structure includes two end plates, each of which is provided with a current collecting plate on its inner side, a battery unit is provided between the two current collecting plates, the battery unit is composed of a plurality of bipolar plates and a membrane electrode, a membrane electrode is provided between each adjacent bipolar plate, and a plurality of air channels connected to the membrane electrode are opened on one side of each bipolar plate, and a partition is provided in the air channel.

[0009] Furthermore, fuel flow ports are formed at the two ends of the bipolar plate beyond the membrane electrode portion.

[0010] Furthermore, the membrane electrode comprises two gas diffusion layers and a proton exchange membrane between the two gas diffusion layers.

[0011] Furthermore, the partition separates the air channel into a reaction channel and a cooling channel, and the cross-sectional area of ​​the cooling channel is larger than the cross-sectional area of ​​the reaction channel.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The air channel and the membrane electrode reaction area are divided into cooling air (isolated from the membrane electrode) and reaction air (still in contact with the membrane electrode) through the partition, so that the flow ratio of cooling air and reaction air in the whole battery can be distributed. Under the condition of ensuring large flow heat dissipation of cooling air, the reaction air still maintains the small flow required for appropriate reaction, avoiding excessive moisture in the membrane electrode being blown away by the reaction air, and improving the battery performance under high power.

[0014] 2. This solution distributes the air flow without significantly increasing the air flow resistance, thus avoiding power consumption loss of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a three-dimensional diagram of a novel air-cooled fuel cell structure of the present invention.

[0016] Figure 2 It is a schematic diagram of the structure of the battery unit in the present invention.

[0017] Figure 3 It is a schematic diagram of the battery cell structure of another bipolar plate.

[0018] In the figure, the corresponding relationship between the component names and the figure numbers is as follows:

[0019] 1. End plate; 2. Current collecting plate; 3. Bipolar plate; 4. Gas diffusion layer; 5. Proton exchange membrane; 7. Membrane electrode; 8. Separator; 301. Fuel flow port; 302. Air channel. DETAILED DESCRIPTION

[0020] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Example:

[0024] As attached Figure 1 To Attachment Figure 2 As shown:

[0025] The present invention provides a novel fuel cell structure, including two end plates 1, each of which is provided with a current collecting plate 2 on the inner side, and battery cells are arranged in an array between the two current collecting plates 2, and the battery cells are composed of a plurality of bipolar plates 3 and a membrane electrode 7, and a membrane electrode 7 is arranged between each adjacent bipolar plate 3, and a plurality of air channels 302 connected to the membrane electrode 7 are opened at the positive electrode of the bipolar plate 3, and the current collecting plate 2 at the positive end of the battery is directly connected to the positive electrode of the bipolar plate 3, and the parts of the two ends of the bipolar plate 3 that exceed the membrane electrode 7 form fuel flow ports 301, and a plurality of longitudinal flow channels are arranged at the negative end of the bipolar plate 3, and the longitudinal flow channels are perpendicular to the channels 302, and the fuel flow ports 301 at the two ends form a fuel channel loop with the longitudinal flow channels. In other embodiments, the longitudinal flow channels can also be arranged to bend horizontally, wave-shaped, etc., and similarly connect the fuel flow ports 301 at the two ends.

[0026] The membrane electrode 7 includes two gas diffusion layers 4 and a proton exchange membrane 5 between the two gas diffusion layers 4 .

[0027] like Figure 2 For the graphite bipolar plate shown, the supply channels 302 for cooling air and reaction air are completely overlapped, and a partition 8 is arranged in the channel 302, which divides the channel 302 into a reaction channel and a cooling channel, so that the cooling air inlet area is larger than the reaction air inlet area (the reaction air is in contact with the membrane electrode 7), thereby adjusting the flow distribution ratio of the cooling air and the reaction air.

[0028] Under the condition of ensuring a large flow rate of cooling air for heat dissipation, the reaction air still maintains a small flow rate required for an appropriate reaction, thereby preventing excessive moisture in the membrane electrode 7 from being swept away by the reaction air.

[0029] like Figure 3 For the metal bipolar plate shown, the partition 8 separates the inlet of the bipolar plate 3 channel 302, so that the cooling air of the metal bipolar plate includes a part of the channel 302 area in addition to the original parallel opening, and the flow distribution ratio of the cooling air and the reaction air is also adjusted.

[0030] The manner of adding the partition 8 does not significantly increase the air flow resistance, thus avoiding the power consumption loss of the fan.

[0031] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A novel air-cooled fuel cell structure, characterized in that: The invention comprises two end plates (1), each of which is provided with a current collecting plate (2) on its inner side, a battery unit is provided between the two current collecting plates (2), the battery unit is composed of a plurality of bipolar plates (3) and a membrane electrode (7), a membrane electrode (7) is provided between each adjacent bipolar plate (3), a plurality of air channels (302) connected to the membrane electrode (7) are provided on one side of each bipolar plate (3), and a partition plate (8) is provided in the air channel (302).

2. A novel air-cooled fuel cell structure as claimed in claim 1, characterized in that: The two ends of the bipolar plate (3) extend beyond the membrane electrode (7) to form fuel flow ports (301).

3. A novel air-cooled fuel cell structure as claimed in claim 1, characterized in that: The membrane electrode (7) comprises two gas diffusion layers (4) and a proton exchange membrane (5) between the two gas diffusion layers (4).

4. A novel air-cooled fuel cell structure as claimed in claim 1, characterized in that: The partition (8) divides the air channel (302) into a reaction channel and a cooling channel, and the cross-sectional area of ​​the cooling channel is larger than the cross-sectional area of ​​the reaction channel.

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