Air-cooled fuel cell stack

Abstract

The utility model discloses an air-cooled fuel cell stack which comprises an upper end plate, a lower end plate, a plurality of bipolar plates and a plurality of membrane electrodes, the bipolar plates and the membrane electrodes are positioned between the upper end plate and the lower end plate and are alternately stacked, and each bipolar plate comprises an anode plate, a cathode plate and a cooling plate positioned between the anode plate and the cathode plate. At least two metal belts which are arranged at intervals are fastened at the peripheries of the upper end plate, the lower end plate, the bipolar plates and the membrane electrodes, and the area, facing the upper end plate or the lower end plate, of each metal belt is provided with a lug boss which is in contact with the upper end plate or the lower end plate. The utility model discloses an air-cooled fuel cell stack. The air-cooled fuel cell stack disclosed by the utility model can compensate thermal expansion and cold contraction caused by temperature change of the stack, the upper end plate, the lower end plate, the bipolar plate and the membrane electrode are kept under constant pressure, and the contact resistance can be kept stable, so that the power generation efficiency is kept stable.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to an air-cooled fuel cell stack. Background Art

[0002] The air-cooled fuel cell stack is composed of end plates, bipolar plates, and membrane electrodes. The bipolar plates are fluid distribution components with good electrical conductivity, thermal conductivity, corrosion resistance, and mechanical strength. The membrane electrodes are electrochemical reaction devices, and the end plates at the ends of both sides are structural components. In the prior art, the fastening method of the fuel cell stack is generally bolted, with multiple bolts symmetrically distributed on both sides of the end plate. The nut pressure on the bolts acts on the end plate, and the end plate presses the bipolar plate and membrane electrode in the middle, thereby ensuring that the bipolar plate and membrane electrode have appropriate contact resistance and airtightness, so as to ensure that the fuel cell stack has the best power generation performance and operation reliability.

[0003] The bolt fastening method for fuel cell stacks has the following problems: 1. The nuts on the bolts apply pressure to the end plates, and this pressure acts on the outer edge of the end plates, which can easily cause the end plates to deform or require higher strength end plate materials and structures to reduce the deformation of the end plates. 2. After the stack expands and contracts for a long time, the nuts are easy to loosen, resulting in insufficient compression force on the stack. Utility Model Content

[0004] The purpose of the utility model is to provide an air-cooled fuel cell stack, which can compensate for the thermal expansion and contraction caused by the temperature change of the fuel cell stack, keep the upper end plate, the lower end plate, the bipolar plate and the membrane electrode under constant pressure, and keep the contact resistance stable, thereby maintaining the stable power generation efficiency.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an air-cooled fuel cell stack, comprising: an upper end plate, a lower end plate and a plurality of bipolar plates and membrane electrodes that are alternately stacked and located between the upper end plate and the lower end plate, the bipolar plates comprising an anode plate, a cathode plate and a cooling plate located between the anode plate and the cathode plate, at least two spaced-apart metal belts are fastened to the upper end plate, the lower end plate and the plurality of bipolar plates and the periphery of the membrane electrode, the metal belt has a protrusion in the area facing the upper end plate or the lower end plate, and the protrusion is in contact with the upper end plate or the lower end plate.

[0006] The further improved scheme in the above technical scheme is as follows:

[0007] 1. In the above scheme, the metal strip is provided with a plurality of through holes in the area located on both sides of the plurality of bipolar plates and the membrane electrode.

[0008] 2. In the above scheme, the plurality of through holes are arranged in sequence from top to bottom.

[0009] 3. In the above solution, the number of the protrusions is at least 2, and adjacent protrusions are arranged at intervals.

[0010] 4. In the above solution, the protrusion is a rib-shaped protrusion, a circular protrusion or a bead-shaped protrusion.

[0011] 5. In the above solution, the metal strip has an insulating coating.

[0012] 6. In the above solution, the bottom surface of the lower end plate is provided with at least two grooves, and the metal belt is embedded in the grooves.

[0013] By using the above technical solution, the utility model has the following advantages compared with the prior art:

[0014] 1. The air-cooled fuel cell stack of the utility model has at least two spaced-apart metal belts fastened to the upper end plate, the lower end plate and several bipolar plates and the periphery of the membrane electrode. The metal belt has a protrusion in the area facing the upper end plate or the lower end plate. The protrusion contacts the upper end plate or the lower end plate, which can compensate for the thermal expansion and contraction caused by the temperature change of the fuel cell stack, keep the upper end plate, the lower end plate, the bipolar plate and the membrane electrode under constant pressure, and keep the contact resistance stable, thereby maintaining the stable power generation efficiency.

[0015] 2. In the air-cooled fuel cell stack of the utility model, a plurality of through holes are opened in the areas where the metal belt is located on both sides of the plurality of bipolar plates and the membrane electrode to reduce air resistance, thereby facilitating heat dissipation of the air-cooled fuel cell stack; in addition, at least two grooves are provided on the bottom surface of the lower end plate, into which the metal belt is embedded, to avoid displacement of the metal belt due to thermal expansion and contraction when the battery stack is switched between working and non-working states, thereby affecting the reliability of power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 It is a schematic diagram of the three-dimensional structure of the air-cooled fuel cell stack of the utility model;

[0017] Attached Figure 2 For attachment Figure 1 Schematic diagram of the structure viewed from above;

[0018] Attached Figure 3 It is a structural schematic diagram of the bipolar plate of the utility model;

[0019] Attached Figure 4 It is a schematic diagram of the three-dimensional structure of the metal belt of the air-cooled fuel cell stack of the utility model.

[0020] In the above figures: 1, upper end plate; 2, lower end plate; 3, bipolar plate; 4, membrane electrode; 5, anode plate; 6, cathode plate; 7, cooling plate; 8, metal belt; 9, protrusion; 10, through hole; 11, groove. DETAILED DESCRIPTION

[0021] The present invention can be further understood through the specific embodiments given below, but they are not intended to limit the present invention.

[0022] Embodiment 1: An air-cooled fuel cell stack comprises: an upper end plate 1, a lower end plate 2 and a plurality of bipolar plates 3 and membrane electrodes 4 which are alternately stacked and located between the upper end plate 1 and the lower end plate 2, wherein the bipolar plates 3 comprise an anode plate 5, a cathode plate 6 and a cooling plate 7 located between the anode plate 5 and the cathode plate 6, at least two spaced-apart metal belts 8 are fastened to the upper end plate 1, the lower end plate 2 and the plurality of bipolar plates 3 and the membrane electrode 4, the metal belt 8 has a protrusion 9 in the area facing the upper end plate 1 or the lower end plate 2, and the protrusion 9 is in contact with the upper end plate 1 or the lower end plate 2; the thermal expansion and contraction caused by the temperature change of the fuel cell stack can be compensated, the upper end plate, the lower end plate, the bipolar plate and the membrane electrode are kept under constant pressure, the contact resistance can be kept stable, and thus the power generation efficiency can be kept stable.

[0023] The number of the protrusions 9 is at least 2, and adjacent protrusions 9 are arranged at intervals.

[0024] The protrusion 9 is a rib-shaped protrusion, a circular protrusion or a bead-shaped protrusion.

[0025] The metal strip 8 has an insulating coating.

[0026] The insulating coating is a Teflon layer or a polyurethane paint layer.

[0027] The bottom surface of the lower end plate 2 is provided with at least two grooves 11, and the metal belt 8 is embedded in the groove 11 to prevent the metal belt from being displaced due to thermal expansion and contraction when the battery stack is switched between working and non-working states, thereby affecting the reliability of power generation.

[0028] Embodiment 2: An air-cooled fuel cell stack comprises: an upper end plate 1, a lower end plate 2 and a plurality of bipolar plates 3 and membrane electrodes 4 which are alternately stacked and located between the upper end plate 1 and the lower end plate 2, wherein the bipolar plate 3 comprises an anode plate 5, a cathode plate 6 and a cooling plate 7 located between the anode plate 5 and the cathode plate 6, at least two spaced-apart metal belts 8 are fastened to the upper end plate 1, the lower end plate 2 and the plurality of bipolar plates 3 and membrane electrodes 4, the metal belt 8 has a protrusion 9 in the area facing the upper end plate 1 or the lower end plate 2, and the protrusion 9 is in contact with the upper end plate 1 or the lower end plate 2; the thermal expansion and contraction caused by the temperature change of the fuel cell stack can be compensated, the upper end plate, the lower end plate, the bipolar plate and the membrane electrode are kept under constant pressure, the contact resistance can be kept stable, and thus the power generation efficiency can be kept stable.

[0029] The metal belt 8 is provided with a plurality of through holes 10 in the area on both sides of the bipolar plates 3 and the membrane electrode 4. The plurality of through holes 10 are arranged in sequence from top to bottom to reduce air resistance, thereby facilitating heat dissipation of the air-cooled fuel cell stack.

[0030] The number of the protrusions 9 is at least 2, and adjacent protrusions 9 are arranged at intervals.

[0031] The protrusion 9 is a rib-shaped protrusion, a circular protrusion or a bead-shaped protrusion.

[0032] The metal strip 8 has an insulating coating.

[0033] The above-mentioned insulating coating is an organic coating layer.

[0034] When the above-mentioned air-cooled fuel cell stack is used, at least two spaced-apart metal belts are fastened to the upper end plate, the lower end plate and several bipolar plates and the periphery of the membrane electrode. The metal belt has a protrusion in the area facing the upper end plate or the lower end plate. This protrusion is in contact with the upper end plate or the lower end plate, which can compensate for the thermal expansion and contraction caused by the temperature change of the stack, keep the upper end plate, the lower end plate, the bipolar plate and the membrane electrode under constant pressure, and keep the contact resistance stable, thereby maintaining the stability of power generation efficiency; in addition, the metal belt is provided with several through holes in the area on both sides of several bipolar plates and membrane electrodes to reduce air resistance, which is beneficial to the heat dissipation of the air-cooled fuel cell stack.

[0035] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. An air-cooled fuel cell stack, comprising: An upper end plate (1), a lower end plate (2) and a plurality of bipolar plates (3) and membrane electrodes (4) located between the upper end plate (1) and the lower end plate (2) and stacked alternately, characterized in that: the bipolar plate (3) comprises an anode plate (5), a cathode plate (6) and a cooling plate (7) located between the anode plate (5) and the cathode plate (6), at least two spaced-apart metal strips (8) are fastened to the periphery of the upper end plate (1), the lower end plate (2) and the plurality of bipolar plates (3) and membrane electrodes (4), and the metal strip (8) has a protrusion (9) in the area facing the upper end plate (1) or the lower end plate (2), and the protrusion (9) is in contact with the upper end plate (1) or the lower end plate (2).

2. The air-cooled fuel cell stack according to claim 1, characterized in that: The metal strip (8) is provided with a plurality of through holes (10) in the area located on both sides of the plurality of bipolar plates (3) and the membrane electrode (4).

3. The air-cooled fuel cell stack according to claim 2, characterized in that: The plurality of through holes (10) are arranged in sequence from top to bottom.

4. The air-cooled fuel cell stack according to claim 1 or 2, characterized in that: The number of the protrusions (9) is at least 2, and adjacent protrusions (9) are arranged at intervals.

5. The air-cooled fuel cell stack according to claim 1 or 2, characterized in that: The protrusion (9) is a rib-shaped protrusion, a circular protrusion or a bead-shaped protrusion.

6. The air-cooled fuel cell stack according to claim 1 or 2, characterized in that: The metal strip (8) has an insulating coating.

7. The air-cooled fuel cell stack according to claim 1 or 2, characterized in that: The bottom surface of the lower end plate (2) is provided with at least two grooves (11), and the metal strip (8) is embedded in the grooves (11).

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