Fuel cell separator

Abstract

The present invention relates to a fuel cell separator comprising: a plurality of bosses arranged in columns configured to contact and support a membrane electrode assembly; and a plurality of channels configured to form a movement path of a reaction gas, each channel being located between two adjacent bosses; wherein branch portions of the bosses are arranged in a first column and an adjacent second column along a movement direction of the reaction gas; wherein the branch portions of the bosses in the first column and the second column are arranged in a discontinuous form; and wherein a length of the bosses in a width direction or a height direction is selectively varied so that the moving reaction gas creates a flow deviation.

Description

Technical Field

[0001] This invention relates to a fuel cell separator. Background Technology

[0002] Generally speaking, a fuel cell is a device that directly electrochemically converts the chemical energy of fuel into electrical energy within the fuel cell, rather than converting chemical energy into heat energy through combustion. It is a pollution-free power generation device and is being widely studied as a power source for vehicles, laser electrical equipment, and other applications.

[0003] Hydrogen is supplied as fuel gas to the anode of the fuel cell, and oxygen is supplied as oxidant to the cathode of the fuel cell. In order to separate electrons from hydrogen and oxygen and promote ionization, humidifiers are installed at both the anode and cathode of the fuel cell to supply moisture to hydrogen and oxygen.

[0004] Based on operating temperature and electrolyte type, fuel cells are classified into solid oxide fuel cells, molten carbonate fuel cells, polymer electrolyte membrane fuel cells, and direct methanol fuel cells.

[0005] In a fuel cell, two electrochemical reactions occur: oxidation at the anode and reduction at the cathode. Catalyst layers, using platinum or a combination of platinum and ruthenium, are formed at each electrode to facilitate oxidation or reduction. Fine carbon particles are used as catalyst supports to reduce the amount of platinum catalyst used and improve its utilization. The final byproducts of the reactions are electricity, heat, and water. Water produced at the cathode exists as water and water vapor and is typically removed by a strong flow of reducing gas (oxygen or air) to the cathode.

[0006] A basic cell in a fuel cell stack comprises two electrodes, an anode and a cathode, separated by a polymer electrolyte membrane (MEM). The MEM and the anode and cathode located on the outer surface of the MEM are hot-pressed to form a membrane electrode assembly (MEA). The MEA is supported by a separator with flow channels. These channels are used to supply hydrogen as fuel (or methanol in the case of a direct methanol fuel cell) and oxygen or air as a reducing gas, and to exhaust water produced by the oxidation-reduction reaction. Gaskets are provided to prevent leakage of gases or liquids supplied or exhausted through the flow channels of the separator. These cell units, including the MEA, separator, and gaskets, are stacked sequentially to achieve the desired output, and the stack is formed by fixing end plates at both ends of the cell units as fixing units.

[0007] The separator serves to electrically connect the two electrodes, prevent the fuel (hydrogen or methanol) and reducing gas (oxygen or air) from mixing in the cell, and provides mechanical support for the stacked cell units. It also allows the fuel (hydrogen or methanol) and reducing gas (oxygen or air) to flow evenly to the electrodes through channels formed on the separator, and prevents the membrane from drying out through proper humidity management. Providing adequately moistened fuel and reducing gas (oxygen or air) is crucial when operating a polymer electrolyte fuel cell.

[0008] Under high current operating conditions exceeding the limiting current density, excess water produced by electrochemical reactions and water removed from the anode through electroosmosis exists at the cathode. Some of the excess water evaporates into the reducing gas (oxygen or air) channel of the partition and saturates the reducing gas. Unevaporated water exists in liquid form in the gas diffusion layer (GDL) or the channel of the partition.

[0009] Excess water present in the gas diffusion layer or partition channels may cause overflow if it is not drained to the outside through proper engineering mechanisms, which could lead to fatal problems for the performance or reliability of the fuel cell.

[0010] The information disclosed in this background section is intended only to enhance the understanding of the background of this invention, and therefore may contain information that does not constitute prior art as defined in patent law. Summary of the Invention

[0011] This invention relates to a fuel cell separator. In a specific embodiment, it relates to a fuel cell separator that facilitates mass exchange between lands by generating a flow rate difference of reactant gases through a pressure difference between adjacent channels.

[0012] To address the aforementioned problems associated with the prior art, embodiments of the present invention were developed. These embodiments provide a fuel cell separator that, by varying the width or height of the bosses, allows for different cross-sectional areas of adjacent channels or different gaps between branches. This enables the generation of flow deviations in reactant gases based on pressure differences between adjacent channels or branches, thereby promoting mass exchange between the bosses and preventing degradation of the fuel cell stack's power generation performance due to overflow.

[0013] Embodiments of the present invention may provide a fuel cell separator configured such that a plurality of bosses configured to contact and support a membrane electrode assembly and a plurality of channels configured to form a movement path for a reactant gas alternately repeat, wherein branches of bosses arranged in a first column and branches of bosses arranged in a second column configured to face the bosses in the first column along the direction of reaction gas movement are arranged in a discontinuous manner, and the length of the bosses along the width or height direction is selectively changed, so that the moving reactant gas produces a flow rate deviation.

[0014] In one embodiment, the length of the boss along the width direction can be changed such that the gap between the first branch of the boss in the first column and the second branch of the boss in the second column is narrower than the gap between the third branch of the boss in the first column and the fourth branch of the boss in the second column.

[0015] In one embodiment, the length of the boss including the first branch and the boss including the second branch along the width direction can be increased, and the length of the boss including the third branch and the boss including the fourth branch along the width direction can be decreased.

[0016] In one embodiment, the boss may be configured such that each of the first to fourth branches has a multi-level structure.

[0017] In one embodiment, the length of the boss along the height direction can be changed such that the gap between the first branch of the boss in the first column and the second branch of the boss in the second column is narrower than the gap between the third branch of the boss in the first column and the fourth branch of the boss in the second column.

[0018] In one embodiment, the length of the boss including the first branch and the boss including the second branch along the height direction can be increased, and the length of the boss including the third branch and the boss including the fourth branch along the height direction can be decreased.

[0019] In one embodiment, the membrane electrode assembly may be configured such that the compression ratio of the portion of the gas diffusion layer facing the boss including the first branch and the boss including the second branch is set to be higher than the compression ratio of the other portions of the gas diffusion layer facing the boss including the third branch and the boss including the fourth branch.

[0020] In one embodiment, the boss may be formed such that each of the first to fourth branches has a multi-level structure.

[0021] In one embodiment, the bosses can be configured such that the cross-sectional area of ​​the channel formed between adjacent bosses can be adjusted by selectively changing the length of the bosses arranged continuously in the first column in a direction perpendicular to the direction of movement along the height direction.

[0022] In one embodiment, the boss can be configured such that by reducing the length of the first and second bosses that are adjacent to each other along the height direction, the cross-sectional area of ​​the channel between the first and second bosses that are adjacent to each other in the plurality of bosses arranged in the first column is greater than the cross-sectional area of ​​the channel between the first boss and the third boss that is adjacent thereto, and the cross-sectional area of ​​the channel between the second boss and the fourth boss that is adjacent thereto.

[0023] In one embodiment, the membrane electrode assembly may be configured such that the compression ratio of the portions of the gas diffusion layer facing the third and fourth protrusions is set to be higher than the compression ratio of the other portions of the gas diffusion layer facing the first and second protrusions.

[0024] In one embodiment, the bosses can be configured such that the cross-sectional area of ​​the channel formed between adjacent bosses can be adjusted by selectively changing the length of the bosses arranged continuously in the first column in a direction perpendicular to the direction of movement along the width direction.

[0025] In one embodiment, the boss can be configured such that by increasing the length of the third boss adjacent to the first boss and the fourth boss adjacent to the second boss in the width direction, the cross-sectional area of ​​the channel between the first boss and the second boss that are adjacent to each other in the plurality of bosses arranged in the first column is greater than the cross-sectional area of ​​the channel between the first boss and the third boss adjacent thereto and the cross-sectional area of ​​the channel between the second boss and the fourth boss adjacent thereto.

[0026] Other aspects and preferred embodiments of the present invention will be discussed below. Attached Figure Description

[0027] The above and other features of the invention will now be described in detail with reference to certain exemplary embodiments shown in the accompanying drawings, which are given illustratively below and are therefore not necessarily limited to the invention, wherein:

[0028] Figure 1 This is a side view showing the length variation along the width direction in the fuel cell separator according to an embodiment of the present invention;

[0029] Figure 2 This is a perspective view showing a branch portion of a fuel cell separator according to an embodiment of the present invention;

[0030] Figure 3 It is along Figure 1 The cross-sectional view taken by line AA shows the structure of the branch portion of the fuel cell separator according to an embodiment of the present invention;

[0031] Figure 4 This is a side view showing the length variation along the height direction in the fuel cell separator according to an embodiment of the present invention;

[0032] Figure 5 It is along Figure 4 The cross-sectional view taken by the BB line shows the compression ratio of the gas diffusion layer of the fuel cell separator according to an embodiment of the present invention;

[0033] Figure 6This is a side view showing the length variation along the height direction in the fuel cell separator according to an embodiment of the present invention;

[0034] Figure 7 It is along Figure 6 A cross-sectional view taken by the CC line shows the compression ratio of the gas diffusion layer of the fuel cell separator according to an embodiment of the present invention; and

[0035] Figure 8 This is a side view showing the length variation along the width direction in the fuel cell separator according to an embodiment of the present invention.

[0036] It is understood that the accompanying drawings are not necessarily drawn to scale and may present a simplified representation of various features illustrating some principles of exemplary embodiments of the invention. Specific design features of the exemplary embodiments of the invention disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, may be determined in part by the specific intended application and usage environment.

[0037] In the figures, reference numerals may refer to the same or equivalent portions of embodiments of the invention in several figures of the figures. Detailed Implementation

[0038] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] The advantages and features of exemplary embodiments of the present invention, as well as methods for implementing them, will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

[0040] However, the present invention is not limited to the embodiments disclosed herein, but can be implemented in various different forms, and embodiments are provided to make the description of the invention detailed and to fully express the scope of the invention to those skilled in the art. It should be noted that the scope of the invention may be defined by the claims.

[0041] In the following description of the invention, details of known functions and configurations incorporated herein may be omitted if they make the subject matter of the invention unclear.

[0042] In the components of each cell in a fuel cell stack, the membrane electrode assembly (MEA) may be located in the innermost region of each cell, and the MEA may be configured such that the catalyst layers of the anode and cathode are applied to both surfaces of the polymer electrolyte membrane 1.

[0043] The gas diffusion layer (GDL) 10 can be located outside the membrane electrode assembly, i.e. outside the catalyst layer, and a separator with channels 200 can be formed thereon to supply fuel and discharge water produced by the reaction, and can be stacked outside the gas diffusion layer 10.

[0044] In the case of channel 200, since the multiple bosses 100 that contact and support the membrane electrode assembly can have the same length in the width direction and the same length in the height direction, the cross-sectional area of ​​channel 200 can also be the same. If the cross-sectional area of ​​channel 200 is the same, the reaction water and droplets from the humidifier may accumulate on the bosses 100 and may cause overflow, and this overflow may lead to membrane deterioration and deterioration of drainage performance.

[0045] Therefore, the length of multiple channels 200 along the width direction or along the height direction can be changed so that the cross-sectional areas of adjacent channels 200 are different from each other. As a result, the flow rate deviation of the reactant gas is generated due to the pressure difference between the channels 200, which can promote the exchange of matter between adjacent channels 200 and suppress overflow.

[0046] Figure 1 This is a side view showing the length variation along the width direction in the fuel cell separator according to an embodiment of the present invention. Figure 2 This is a perspective view showing a branch of the fuel cell diaphragm. Figure 3 It is along Figure 1 The cross-sectional view taken along line AA shows the structure of the branch section of the fuel cell separator.

[0047] In this embodiment, such as Figure 1 As shown, branches 102 and 104 of the plurality of bosses 100 can be arranged in a first column; branches 112 and 114 of the plurality of bosses 110 can be arranged in a second column, facing branches 102 and 104 along the direction of movement of the reactant gas; and can be arranged in a discontinuous manner. The lengths of the bosses 100 and 110 along the width direction or along the height direction can be selectively changed, so that the flow rate of the moving reactant gas can be deviated.

[0048] In other words, the lengths of the bosses 100 and 110 along the width direction can be changed so that the gap G1 between the first branch 102 of the boss 100 in the first column and the second branch 112 of the boss 110 in the second column can be narrower than the gap G2 between the third branch 104 of the boss 100 in the first column and the fourth branch 114 of the boss 110 in the second column.

[0049] More specifically, in bosses 100 and 110, the lengths of bosses 100 including the first branch 102 and bosses 110 including the second branch 112 in the width direction can be increased, and the lengths of bosses 100 including the third branch 104 and bosses 110 including the fourth branch 114 in the width direction can be decreased, such that the gap G1 between the first branch 102 of the bosses 100 in the first column and the second branch 112 of the bosses 110 in the second column is narrower than the gap G2 between the third branch 104 of the bosses 100 in the first column and the fourth branch 114 of the bosses 110 in the second column, thereby enabling a flow deviation of the reactant gas moving along the channel 200.

[0050] This is because when gas flows through channels with different cross-sectional areas at the same flow rate, the flow velocity is fastest and the pressure is highest in the channel with the smallest cross-sectional area, and the flow velocity is slowest and the pressure is lowest in the channel with the largest cross-sectional area. If a pressure difference is generated in channel 200 due to the change in cross-sectional area caused by this gap difference, a flow deviation can occur when the working fluid moves from a region with narrow gaps to a region with wide gaps. This flow deviation can promote the exchange of matter between bosses 100 and 110, thereby suppressing the overflow above bosses 100 and 110.

[0051] Here, as Figure 2 As shown, bosses 100 and 110 can be formed such that the first, second, third and fourth branches 102, 112, 104 and 114 have a multi-level structure.

[0052] More specifically, in a structure in which the branches 102 and 104 of the bosses 100 arranged in the first column, and the branches 112 and 114 of the bosses 110 arranged in the second column facing the branches 102 and 104 along the direction of movement of the reactant gas, can be arranged in a discontinuous manner, the bosses 100 and 110 can be formed such that the first, second, third, and fourth branches 102, 112, 104, and 114 have a multi-level structure, such as... Figure 2 As shown.

[0053] like Figure 3 As shown, it is along Figure 1 The cross-sectional view taken by line AA shows the structure of branch 102. For example, since the first branch 102 of boss 100 can have a multi-level structure, at the first branch 102, a portion of the height of boss 100 is reduced, thereby ensuring the flow space A of the reaction gas corresponding to the reduced height, and through the flow space A, material exchange can be carried out between adjacent channels 200, thereby suppressing the overflow above boss 100.

[0054] Figure 4 This is a side view showing the length variation along the height direction in a fuel cell separator according to another embodiment of the present invention. Figure 5 It is along Figure 4 The cross-sectional view taken from the BB line shows the compression ratio of the gas diffusion layer of the fuel cell separator.

[0055] In this embodiment, such as Figure 4 As shown, the branches 102 and 104 of the plurality of bosses 100 arranged in the first column, and the branches 112 and 114 of the plurality of bosses 110 arranged in the second column facing the branches 102 along the direction of movement of the reactant gas, can be arranged in a discontinuous form, and the length of the bosses 100 and 110 along the width direction or along the height direction can be selectively changed, so that the moving reactant gas can produce a flow deviation.

[0056] In other words, the lengths of the bosses 100 and 110 along the height direction can be changed, such that the gap G1 between the first branch 102 of the boss 100 in the first column and the second branch 112 of the boss 110 in the second column is narrower than the gap G2 between the third branch 104 of the boss 100 in the first column and the fourth branch 114 of the boss 110 in the second column.

[0057] More specifically, in bosses 100 and 110, by increasing the length along the height direction of boss 100 including the first branch 102 and boss 110 including the second branch 112, and decreasing the length along the height direction of boss 100 including the third branch 104 and boss 110 including the fourth branch 114, the gap G1 between the first branch 102 of the bosses 100 in the first column and the second branch 112 of the bosses 110 in the second column becomes narrower than the gap G2 between the third branch 104 of the bosses 100 in the first column and the fourth branch 114 of the bosses 110 in the second column, thereby enabling a flow deviation of the reactant gas moving along the channel 200.

[0058] This is because when gas flows through channels with different cross-sectional areas at the same flow rate, the flow rate is fastest and the pressure is highest in the channel with the smallest cross-sectional area, and the flow rate is slowest and the pressure is lowest in the channel with the largest cross-sectional area. If a pressure difference is generated in channel 200 due to the change in cross-sectional area caused by this gap difference, a flow deviation will occur when the working fluid moves from the area with narrow gaps to the area with wide gaps. This flow deviation can promote the exchange of matter between bosses 100 and 110, thereby suppressing the overflow above bosses 100 and 110.

[0059] In this structure, due to the height difference between each boss 100 in the first column and its adjacent boss 100 (see... Figure 3 Therefore, accordingly, such as Figure 5 As shown, the compression ratio of the gas diffusion layer 10 facing the boss 100 including the first branch 102 can be set to be higher than the compression ratio of the other part 10' of the gas diffusion layer facing the boss 100' including the third branch 104.

[0060] According to this embodiment, the bosses 100 and 110 can be formed such that the first, second, third, and fourth branches 102, 112, 104, and 114 have a multi-level structure (see...). Figure 2 ).

[0061] More specifically, in a structure in which the branches 102 and 104 of the bosses 100 arranged in the first column, and the branches 112 and 114 of the bosses 110 arranged in the second column facing the branches 102 and 104 along the direction of reaction gas movement, can be arranged in a discontinuous manner, the bosses 100 and 110 can be formed such that the first, second, third, and fourth branches 102, 112, 104, and 114 have a multi-level structure (see...). Figure 2 ).

[0062] Therefore, for example, since the first branch 102 of the boss 100 has a multi-level structure, at the first branch 102, a portion of the height of the boss 100 is reduced, thereby ensuring the flow space A of the reactant gas corresponding to the reduced height (see...). Figure 3 Furthermore, material exchange can occur between adjacent channels 200 via the flow space A, thereby suppressing overflow above the boss 100.

[0063] Figure 6 This is a side view showing the length variation along the height direction in the fuel cell separator according to an embodiment of the present invention. Figure 7 It is along Figure 6 The cross-sectional view taken by the CC line shows the compression ratio of the gas diffusion layer of the fuel cell separator.

[0064] In this embodiment, such as Figure 6 As shown, the branches 102 and 104 of the plurality of bosses 100 arranged in the first column, and the branches 112 and 114 of the plurality of bosses 110 arranged in the second column facing the branches 102 along the direction of movement of the reactant gas, can be arranged in a discontinuous form, and the length of the bosses 100 and 110 along the width direction or along the height direction can be selectively changed, so that the moving reactant gas can produce a flow deviation.

[0065] For example, by selectively changing the length along the height direction of the bosses 100 arranged continuously in the first column in a direction perpendicular to the direction of movement of the reactant gas, the cross-sectional area of ​​the channel 200 formed between adjacent bosses 100 can be adjusted.

[0066] More specifically, among the multiple protrusions 100 arranged in the first column, by reducing the length of the first protrusion 100-1 and the second protrusion 100-2 along the height direction and increasing the length of the third protrusion 100-3 and the fourth protrusion 100-4 along the height direction, the cross-sectional area P1 of the channel 200 between adjacent first protrusions 100-1 and second protrusions 100-2 can be adjusted to be larger than the cross-sectional area P2 of the channel 200 between the first protrusion 100-1 and the third protrusion 100-3 and the cross-sectional area P3 of the channel 200 between the second protrusion 100-2 and the fourth protrusion 100-4.

[0067] This is because when gas flows through channels with different cross-sectional areas at the same flow rate, the flow velocity is fastest and the pressure is highest in the channel with the smallest cross-sectional area, while the flow velocity is slowest and the pressure is lowest in the channel with the largest cross-sectional area. If a pressure difference is generated in channel 200 due to the change in cross-sectional area caused by the height adjustment between multiple adjacent bosses 100-1 to 100-4, a flow deviation will occur when the working fluid moves from the area with a small cross-sectional area to the area with a large cross-sectional area. This flow deviation can promote the exchange of substances between bosses 100-1 to 100-4, thereby suppressing the overflow above bosses 100-1 to 100-4.

[0068] In this structure, since there may be a height difference between each boss 100 in the first column and the adjacent bosses 100-1 to 100-4 (see... Figure 6 Therefore, accordingly, such as Figure 7 As shown, the compression ratio of a portion of the gas diffusion layer 10 facing the boss 100-3 can be set to be higher than the compression ratio of the other portion 10' of the gas diffusion layer 10 facing the boss 100-1.

[0069] According to this embodiment, the bosses 100 and 110 can be formed such that the first, second, third, and fourth branches 102, 112, 104, and 114 have a multi-level structure (see...). Figure 2 ).

[0070] Specifically, in a structure in which the branches 102 and 104 of the bosses 100 arranged in the first column, and the branches 112 and 114 of the bosses 110 arranged in the second column facing the branches 102 and 104 along the direction of movement of the reactant gas are arranged in a discontinuous manner, the bosses 100 and 110 can be formed such that the first, second, third, and fourth branches 102, 112, 104, and 114 have a multi-level structure (see...). Figure 2 ).

[0071] Therefore, for example, since the first branch 102 of the boss 100 has a multi-level structure, at the first branch 102, a portion of the height of the boss 100 is reduced, thereby ensuring the flow space A of the reactant gas corresponding to the reduced height (see...). Figure 3 Furthermore, material exchange can occur between adjacent channels 200 via the flow space A, thereby suppressing overflow above the boss 100.

[0072] Figure 8 This is a view showing the variation in length along the width direction in a fuel cell separator according to another embodiment of the present invention.

[0073] In this embodiment, such as Figure 8 As shown, the branches 102 and 104 of the plurality of bosses 100 arranged in the first column, and the branches 112 and 114 of the plurality of bosses 110 arranged in the second column facing the branches 102 along the direction of movement of the reactant gas, can be arranged in a discontinuous form, and the length of the bosses 100 and 110 along the width direction or along the height direction can be selectively changed, so that the moving reactant gas can produce a flow deviation.

[0074] For example, by selectively changing the length along the width direction of the bosses 100 arranged continuously in the first column in a direction perpendicular to the direction of movement of the reactant gas, the cross-sectional area of ​​the channel 200 formed between adjacent bosses 100 can be adjusted.

[0075] More specifically, among the multiple protrusions 100 arranged in the first column, by increasing the length along the width direction of the third protrusion 100-3 adjacent to the first protrusion 100-1 and the fourth protrusion 100-4 adjacent to the second protrusion 100-2, the cross-sectional area P1 of the channel 200 between the adjacent first protrusion 100-1 and the second protrusion 100-2 can be adjusted to be larger than the cross-sectional area P2 of the channel 200 between the first protrusion 100-1 and the third protrusion 100-3 and the cross-sectional area P3 of the channel 200 between the second protrusion 100-2 and the fourth protrusion 100-4.

[0076] This is because when gas flows through channels with different cross-sectional areas at the same flow rate, the flow velocity is fastest and the pressure is highest in the channel with the smallest cross-sectional area, while the flow velocity is slowest and the pressure is lowest in the channel with the largest cross-sectional area. If a pressure difference is generated in channel 200 due to the change in cross-sectional area caused by the width adjustment of the third boss 100-3 and the fourth boss 100-4, a flow deviation will occur when the working fluid moves from the area with a small cross-sectional area to the area with a large cross-sectional area. This flow deviation will promote the exchange of matter between bosses 100-1 to 100-4, thereby suppressing the overflow above bosses 100-1 to 100-4.

[0077] For example, bosses 100 and 110 can be formed such that the first branch 102 of the boss 100 in the first column (which faces the second branch 112 of the boss 110 in the second column) has a multi-level structure (see...). Figure 2 ).

[0078] Specifically, in a structure in which the branches 102 of the bosses 100 arranged in the first column and the branches 112 of the bosses 110 arranged in the second column facing the branches 102 along the direction of movement of the reactant gas are arranged in a discontinuous manner, the bosses 100 and 110 can be formed such that the branches 102 and 112 have a multi-level structure (see...). Figure 2 ).

[0079] Therefore, for example, since the first branch 102 of the boss 100 has a multi-level structure, at the first branch 102, a portion of the height of the boss 100 can be reduced, thereby ensuring the flow space A of the reactant gas corresponding to the reduced height (see...). Figure 3 Furthermore, material exchange can occur between adjacent channels 200 via the flow space A, thereby suppressing overflow above the boss 100.

[0080] In embodiments of the present invention, the width or height of the bosses can be changed so that the cross-sectional areas of adjacent channels are different from each other, thereby generating a pressure difference. This pressure difference can be used to make the reactive gas flow to the adjacent channels and promote the exchange of matter between the bosses, thereby preventing the degradation of the power generation performance of the battery stack due to overflow.

[0081] In embodiments of the present invention, the width or height of the boss can be changed so that the gap between adjacent branches is different from each other, thereby causing a deviation in the flow rate of the reactant gas and promoting the exchange of matter between the bosses, thus preventing the degradation of the power generation performance of the battery stack due to overflow.

[0082] As is evident from the above description, embodiments of the present invention can change the width or height of the bosses so that the cross-sectional areas of adjacent channels can be different from each other, thereby generating a pressure difference. This pressure difference can be used to make the reactive gas flow to the adjacent channels and promote the exchange of matter between the bosses, thereby preventing the degradation of the battery stack's power generation performance due to overflow.

[0083] In embodiments of the present invention, the width or height of the boss can be changed so that the gap between adjacent branches is different from each other, thereby causing a deviation in the flow rate of the reactant gas and promoting the exchange of matter between the bosses, thus having the effect of preventing the degradation of the battery stack's power generation performance due to overflow.

[0084] This document has disclosed several implementation methods. It should be understood that various features of different implementation methods can be combined.

[0085] The invention has been described in detail with reference to exemplary embodiments. However, those skilled in the art will understand that changes can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A fuel cell separator, comprising: Multiple protrusions arranged in a row are configured to contact and support the membrane electrode assembly; as well as Multiple channels are configured to form a movement path for the reactant gas, with each channel located between two adjacent bosses; The branches of the boss are arranged in the first column and the adjacent second column along the direction of movement of the reacting gas; In this configuration, the branches of the bosses in the first and second columns are arranged in a discontinuous manner; and In this method, the length of the boss along the width or height direction is selectively changed, causing the moving reactant gas to have a flow rate deviation.

2. The fuel cell separator according to claim 1, wherein, The bosses have different lengths along their width, such that the gap between the first branch of the bosses in the first column and the second branch of the bosses in the second column is narrower than the gap between the third branch of the bosses in the first column and the fourth branch of the bosses in the second column.

3. The fuel cell separator according to claim 2, wherein: The length of the boss in the width direction of the first branch is greater than the length of the bosses in the width direction of the other parts arranged in the first column. The length of the boss in the width direction, including the third branch, is less than the length of the bosses in the width direction of the other parts arranged in the first column. The length of the boss in the second branch along the width direction is greater than the length of the bosses in the width direction of the other parts arranged in the second column; and The length of the boss in the width direction, including the fourth branch, is greater than the length of the bosses in the width direction of the other parts arranged in the first column.

4. The fuel cell separator according to claim 2, wherein, Each of the first branch to the fourth branch has a multi-level structure.

5. The fuel cell separator according to claim 1, wherein, The bosses have different lengths along the height direction, so that the gap between the first branch of the bosses in the first column and the second branch of the bosses in the second column is narrower than the gap between the third branch of the bosses in the first column and the fourth branch of the bosses in the second column.

6. The fuel cell separator according to claim 5, wherein: The length of the boss in the height direction of the first branch is greater than the length of the bosses in the height direction of the other parts arranged in the first column; The length of the boss in the height direction of the third branch is less than the length of the bosses in the height direction of the other parts arranged in the first column; The length of the boss in the second branch along the height direction is greater than the length of the bosses in the height direction of the other parts arranged in the second column; and The length of the boss in the fourth branch along the height direction is greater than the length of the bosses in the height direction of the other parts arranged in the first column.

7. The fuel cell separator according to claim 6, wherein, The membrane electrode assembly is configured such that the compression ratio of the portion of the gas diffusion layer facing the boss including the first branch and the boss including the second branch is set to be higher than the compression ratio of the other portions of the gas diffusion layer facing the boss including the third branch and the boss including the fourth branch.

8. The fuel cell separator according to claim 5, wherein, Each of the first to fourth branches has a multi-level structure.

9. The fuel cell separator according to claim 1, wherein, By changing the length of the bosses arranged continuously in the first column along the direction perpendicular to the direction of movement along the height direction, the cross-sectional area of ​​the channel formed between adjacent bosses is made different.

10. The fuel cell separator according to claim 9, wherein, The protrusions are configured such that, among the protrusions arranged in the first column, the lengths of adjacent first and second protrusions along the height direction are reduced, such that the cross-sectional area of ​​the channel between adjacent first and second protrusions is greater than the cross-sectional area of ​​the channel between the first protrusion and its adjacent third protrusion, and the cross-sectional area of ​​the channel between the second protrusion and its adjacent fourth protrusion.

11. The fuel cell separator according to claim 10, wherein, The membrane electrode assembly is configured such that the compression ratio of the portion of the gas diffusion layer facing the third and fourth protrusions is set to be higher than the compression ratio of the other portions of the gas diffusion layer facing the first and second protrusions.

12. The fuel cell separator according to claim 1, wherein, By changing the length of the bosses arranged continuously in the first column along the direction perpendicular to the direction of movement along the width direction, the cross-sectional area of ​​the channel formed between adjacent bosses is made different.

13. The fuel cell separator according to claim 12, wherein, By increasing the length of the third boss adjacent to the first boss and the fourth boss adjacent to the second boss along the width direction, the cross-sectional area of ​​the channel between the first boss and the second boss that are adjacent to each other in the plurality of bosses arranged in the first column is greater than the cross-sectional area of ​​the channel between the first boss and the third boss adjacent to it, and the cross-sectional area of ​​the channel between the second boss and the fourth boss adjacent to it.

14. A fuel cell separator, comprising: The first protrusion extends along the first diagonal direction of the first column; The second boss extends along the second diagonal direction in the second column, wherein the second diagonal direction intersects the first diagonal direction, forming a first gap between the first boss and the second boss; A third protrusion extends along the third diagonal direction of the first column, wherein the third diagonal direction is parallel to the first diagonal direction, forming a first channel between the first protrusion and the third protrusion; and A fourth protrusion extends along the fourth diagonal direction in the second column, wherein the fourth diagonal direction intersects the third diagonal direction and is parallel to the second diagonal direction, forming a second channel between the second protrusion and the fourth protrusion, and forming a second gap between the third protrusion and the fourth protrusion, wherein the first gap is not aligned with the second gap and the first gap is smaller than the second gap.

15. The fuel cell separator according to claim 14, wherein, The lengths of the first boss and the second boss along the first width direction are different from the lengths of the third boss and the fourth boss along the second width direction.

16. The fuel cell separator according to claim 15, wherein, The lengths of the first boss and the second boss along the first width direction are greater than the lengths of the third boss and the fourth boss along the second width direction.

17. The fuel cell separator according to claim 14, wherein, The lengths of the first and second protrusions along the first height direction are different from the lengths of the third and fourth protrusions along the second height direction.

18. The fuel cell separator according to claim 17, wherein, The lengths of the first boss and the second boss along the first height direction are greater than the lengths of the third boss and the fourth boss along the second height direction.

19. The fuel cell separator according to claim 14, wherein, Each of the first boss, the second boss, the third boss, and the fourth boss has a stepped thickness structure at the tip of its proximity to the first gap and the second gap.

20. The fuel cell separator according to claim 14, wherein, The lengths of the first boss and the fourth boss along the first width direction and / or along the first height direction are different from the lengths of the second boss and the third boss along the second width direction and / or along the second height direction.

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