Bipolar plate element having a flow-disruption structure

Abstract

The invention relates to a plate element, in particular a bipolar plate element, for an electrochemical system, which can be a fuel cell system, for example, the plate element comprising the following: an operating-fluid distribution structure on a first of the two main surfaces of the plate element, the operating-fluid distribution structure having at least one operating-fluid distribution channel; and a flow-disruption structure on the first main surface of the plate element between the operating-fluid distribution structure and an edge of the plate element.

Description

[0001] BIPOLAR PLATE ELEMENT WITH FLOW DISTURBANCE STRUCTURE

[0002] The present invention relates to a plate element, which may in particular be a bipolar plate element. The invention also relates to a bipolar plate, a plate arrangement, which may in particular be a bipolar plate arrangement, and an electrochemical system, which may in particular be a fuel cell system.

[0003] Plate elements, which can serve in particular as bipolar plate elements for electrochemical systems, e.g., fuel cell systems, often have operating fluid distribution structures. Operating fluid distribution structures can, in particular, contribute to the desired surface distribution of an operating fluid on a bipolar plate surface. Consequently, the most uniform distribution of operating fluid possible can be achieved on the corresponding catalyst layer, in particular on an adjacent membrane electrode assembly (MEA). This can ideally promote uniform electrochemical conversion across the entire surface of the operating fluid distribution structure. For this purpose, an operating fluid distribution structure can, for example, have a plurality of operating fluid distribution channels.

[0004] One problem can be that, due to manufacturing processes, so-called bypass channels can form at the edges of operating fluid distribution structures. A portion of the operating fluid can flow past the operating fluid distribution structures through bypass channels, making this portion unavailable for a desired electrochemical conversion. This can reduce the efficiency of the electrochemical conversion or the effectiveness of an electrochemical system.

[0005] Various suggestions for improvement have been made to solve or mitigate problems that may arise due to the bypass channels.

[0006] For example, document DE 102007 048 184 B3 describes an electrochemical system consisting of a layered arrangement of several cells, each separated from one another by bipolar plates. The bipolar plates have openings for cooling or for the supply and discharge of operating media to the cells, and the layering can be subjected to mechanical compressive stress. At least one cell has an electrochemically active region surrounded by a boundary wall of the bipolar plate. Within the electrochemically active region, a channel structure of the bipolar plate is provided for uniform media distribution, with at least one gas diffusion layer being provided for the micro-distribution of medium. Boundary elements are provided in the boundary region between the channel structure and the boundary wall to prevent fluid from flowing past the channel structure and the boundary wall.The gas diffusion layer covers the channel structure and / or at least parts of the boundary elements. The electrochemical system described in document DE 102007 048 184 B3 is intended to prevent performance fluctuations due to insufficient media distribution in the electrochemically active region.

[0007] Document WO 2021 / 233647 A1 provides for at least one bypass channel at the edge of at least one of the flow fields of a bipolar plate. At least one flow connection is assigned to the bypass channel, which branches off from the bypass channel into an adjacent edge channel of the flow field. This is intended to improve the utilization of at least one of the reactants.

[0008] Document WO 2021 / 239356 A1 also provides for at least one bypass channel to be present at the edge of at least one of the flow fields of a bipolar plate. The flow resistance in the bypass channel is determined by the design of the bypass channel, eliminating the need for a blocking element extending into the cross-section of the bypass channel. This should make it easier to adjust the flow through a reaction gas bypass. It is preferred if the length of the bypass channel is increased by repeated changes in direction between the inlet port and the outlet port. This should provide a parameter for adjusting the flow resistance in a simple and easy-to-manufacture manner by increasing the contact area of ​​the flow through the bypass channel with the channel wall.

[0009] Document WO 2018 / 220065 A1 describes a separator plate for an electrochemical system, in particular for a bipolar plate of an electrochemical system. The separator plate comprises barrier elements formed integrally with the separator plate. The barrier elements are designed to reduce or prevent the flow of reaction medium along the first flat side of the separator plate along a bead and past an active region, i.e., a bypass.

[0010] At least one of the barrier elements should be lowered at least in some areas, in particular to reduce or prevent a flow of cooling medium on the second flat side of the separator plate.

[0011] The invention is based on the object of providing a plate element, in particular a bipolar plate element, a bipolar plate, a plate arrangement and / or an electrochemical system, which is of simple construction, can be produced with little effort, enables efficient operation of an electrochemical system and / or with which a precise electrochemical system can be produced with little effort.

[0012] This object is achieved by the plate element, in particular bipolar plate element, according to the relevant independent claim.

[0013] The term “in particular” is used in this description and the appended claims to describe optional features.

[0014] The plate element may be a plate element for an electrochemical system.

[0015] The bipolar plate element can be a bipolar plate element for an electrochemical system. The electrochemical system can be, for example, a fuel cell system.

[0016] The plate element may in particular comprise: an operating fluid distribution structure on a first of the two main surfaces of the plate element, wherein the operating fluid distribution structure comprises at least one operating fluid distribution channel, and a flow disturbance structure on the first main surface of the plate element between the operating fluid distribution structure and an edge of the plate element.

[0017] The operating fluid distribution structure can, in particular, contribute to a flat distribution of an operating fluid on the first main surface of the plate element. The operating fluid distribution structure can advantageously define a flow field.

[0018] It may be advantageous if the operating fluid distribution structure and / or the flow field comprises a plurality of operating fluid distribution channels and / or operating fluid distribution channel sections.

[0019] It may be advantageous if the plate element comprises: a fluid barrier structure on the first main surface of the plate element, wherein a portion of the fluid barrier structure is located between the flow disturbance structure and the edge of the plate element.

[0020] The fluid barrier structure can extend directly to the edge of the plate element or be spaced from the edge of the plate element. It can be advantageous if the entire fluid barrier structure extends directly to the edge of the plate element or is spaced from the edge of the plate element. It can be advantageous if at least one section of the fluid barrier structure extends directly to the edge of the plate element and at least another section of the fluid barrier structure is spaced from the edge of the plate element.

[0021] The plate element may be a metallic plate element, comprise a metallic plate element which may, for example, be coated, or comprise a metallic plate core.

[0022] It may be advantageous if the operating fluid distribution structure, the flow disturbance structure and / or the fluid barrier structure have a bead or half-bead, preferably a bead, and / or are formed by deformation of the metallic plate element or the metallic plate core.

[0023] The operating fluid distribution structure, the flow disruption structure, and / or the fluid barrier structure can comprise or be components or layers arranged or attached to the first main surface of the plate element, or can be reinforced by components or layers arranged or attached to the first main surface. It can be advantageous if the plate element comprises the following: a bypass channel through which a portion of an operating fluid can flow past the operating fluid distribution structure.

[0024] The portion of the operating fluid that is able to flow past the operating fluid distribution structure through the bypass channel may be a portion of the operating fluid that does not enter the operating fluid distribution structure or has escaped from the operating fluid distribution structure.

[0025] It may be advantageous if a section of the bypass channel or the entire bypass channel extends between the operating fluid distribution structure and the fluid barrier structure.

[0026] It may be advantageous if at least one opening exists that connects the bypass channel to the at least one operating fluid distribution channel. For example, an outer boundary of the distribution structure can separate the operating fluid distribution structure from the bypass channel. Advantageously, the opening can be an interruption of the outer boundary of the distribution structure or can extend through the outer boundary of the distribution structure.

[0027] It may be advantageous if the plate element has a backflow region and / or a preflow region. For example, the plate element can have the backflow region and / or the preflow region in the bypass channel, the bypass channel can have the backflow region and / or the preflow region, or the bypass channel can be formed entirely or partially from backflow regions and / or preflow regions.

[0028] A return flow area can be understood as a region of the plate element, e.g. the bypass channel, in which a fluid flow can occur opposite or obliquely opposite to the direction of the bypass channel.

[0029] A preflow area can be understood, in particular, as a region of the plate element, e.g., the bypass channel, in which a fluid flow can occur in the direction of the bypass channel or at an angle to the direction of the bypass channel, but not opposite to the direction of the bypass channel. It can be advantageous if a backflow area flows into a preflow area or into the surrounding or adjacent bypass channel.

[0030] It may be advantageous if the opening connects a pre-flow area or an intermediate area located between two pre-flow areas with the at least one operating fluid distribution channel.

[0031] It may be advantageous if the flow disturbance structure or a portion of the flow disturbance structure is located between the operating fluid distribution structure and the fluid barrier structure; and / or is spaced apart from the operating fluid distribution structure; and / or is spaced apart from the fluid barrier structure.

[0032] If the flow disturbance structure or a portion of the flow disturbance structure is located between the operating fluid distribution structure and the fluid barrier structure, the flow disturbance structure or the portion of the flow disturbance structure can, for example, be located in the bypass channel between the operating fluid distribution structure and the fluid barrier structure.

[0033] If the flow disturbance structure or the portion of the flow disturbance structure is spaced from the operating fluid distribution structure, the flow disturbance structure or the portion of the flow disturbance structure can, for example, be spaced from a distribution structure outer wall of the operating fluid distribution structure.

[0034] If the flow disturbance structure or the portion of the flow disturbance structure is spaced from the fluid barrier structure, the flow disturbance structure or the portion of the flow disturbance structure can be spaced, for example, from an inner barrier wall of the fluid barrier structure. The flow disturbance structure or the portion of the flow disturbance structure can be considered spaced from the operating fluid distribution structure in particular if the first main surface between the operating fluid distribution structure and the flow disturbance structure or the portion of the flow disturbance structure is not raised or is raised to a lesser extent, so that a bypass recess extending along the bypass channel exists between the operating fluid distribution structure and the flow disturbance structure or between the operating fluid distribution structure and the portion of the flow disturbance structure.

[0035] The flow disturbance structure or the portion of the flow disturbance structure can be considered to be spaced apart from the fluid barrier structure in particular if the first main surface between the fluid barrier structure and the flow disturbance structure or the portion of the flow disturbance structure is not raised or is raised to a lesser extent, so that there is a bypass recess extending along the bypass channel between the fluid barrier structure and the flow disturbance structure or between the fluid barrier structure and the portion of the flow disturbance structure.

[0036] The flow disturbance structure or the portion of the flow disturbance structure can be considered to be spaced apart from the distribution structure outer wall in particular if the first main surface between the distribution structure outer wall and the flow disturbance structure or between the distribution structure outer wall and the portion of the flow disturbance structure is not raised.

[0037] The flow disturbance structure or the portion of the flow disturbance structure can be considered to be spaced apart from the barrier inner wall in particular if the first main surface between the barrier inner wall and the flow disturbance structure or between the barrier inner wall and the portion of the flow disturbance structure is not raised.

[0038] It may be advantageous if the flow disturbance structure on the plate element is more raised than the operating fluid distribution structure. This can be advantageous because a gas diffusion layer or multiple gas diffusion layers of a membrane-electrode assembly between two plate elements, e.g., between two plate elements of adjacent bipolar plates, can be compressed more strongly at their edges between flow disturbance structures than between operating fluid distribution structures. This can be particularly desirable because high permeability for operating fluid may be desired at the operating fluid distribution structures, whereas low permeability of gas diffusion layers at their edges between flow disturbance structures may also be desirable.For example, an edge of a gas diffusion layer can be squeezed between relatively raised flow disturbance structures of two adjacent plate elements and thus advantageously be less permeable to an operating fluid.

[0039] It can be advantageous if the fluid barrier structure of the plate element is more raised than the flow disturbance structure of the plate element. This can be particularly advantageous because it allows for a better sealing effect through or between facing fluid barrier structures of adjacent plate elements, while edge zones of gas diffusion layers can be located between the flow disturbance structures.

[0040] It may be advantageous if the plate element has the following: an internal operating fluid passage between the operating fluid distribution structure and the flow disturbance structure; and / or an external operating fluid passage between the flow disturbance structure and the fluid barrier structure.

[0041] The internal operating fluid passage may, for example, be an internal operating fluid throttling passage.

[0042] The internal operating fluid passage can, for example, exist between the distribution structure outer wall and the flow disturbance structure.

[0043] The external operating fluid passage may, for example, be an external operating fluid throttling passage.

[0044] The external operating fluid passage can, for example, exist between the flow disturbance structure and the inner barrier wall. In accordance with the usual meaning of the term "throttling," the term "operating fluid throttling passage" can, for example, refer to an operating fluid passage that, particularly compared to immediately adjacent zones connected by the operating fluid passage, forms a constriction through which the operating fluid can only flow with increased flow resistance.

[0045] It may be advantageous if an external distance between the flow disturbance structure and the fluid barrier structure is greater than an internal distance between the operating fluid distribution structure and the flow disturbance structure.

[0046] It may be advantageous if the flow disturbance structure has an outer section and an inner section, wherein the outer section is closer to the fluid barrier structure than the inner section and the inner section is closer to the operating fluid distribution structure than the outer section.

[0047] It may be advantageous if the internal operating fluid passage, e.g., operating fluid throttling passage, is located between the operating fluid distribution structure and the internal section of the flow disturbance structure, for example, between the distribution structure outer wall and the internal section of the flow disturbance structure; and / or the external operating fluid passage, e.g., operating fluid throttling passage, is located between the external section of the flow disturbance structure and the fluid barrier structure, for example, between the external section of the flow disturbance structure and the barrier inner wall.

[0048] It may be advantageous if the plate element has a plurality of internal operating fluid passages and / or external operating fluid passages. It may be preferred if the internal operating fluid passages and / or external operating fluid passages form constrictions which, in the direction of fluid flow, are located between zones with larger flow cross-sections. It may be advantageous if several of the internal operating fluid passages are fluidically connected to one another via intermediate zones with larger flow cross-sections. In the direction of fluid flow, flow can alternate between successive internal operating fluid passages and zones with larger flow cross-sections. This can lead to a sequentially increasing throttling, which can ultimately almost completely prevent fluid flow through the bypass channel.

[0049] It can be advantageous if several of the external operating fluid passages are fluidically connected to each other via intermediate zones with larger flow cross-sections. In the direction of fluid flow, the fluid can alternately flow through successive external operating fluid passages and zones with larger flow cross-sections. This can lead to a sequentially increasing throttling, which can ultimately almost completely prevent fluid flow through the bypass channel.

[0050] The plurality of internal operating fluid passages in the bypass channel may be at least 4, preferably at least 6, e.g. at least 8.

[0051] The plurality of internal operating fluid passages in the bypass channel may be at most 1000, preferably at most 600, e.g. at least 400.

[0052] The number of internal operating fluid passages in the bypass channel may be 4 to 1000, preferably 6 to 600, e.g. 8 to 400.

[0053] The plurality of external operating fluid passages in the bypass channel may be at least 4, preferably at least 6, e.g. at least 8.

[0054] The number of external operating fluid passages in the bypass channel may be at most 1000, preferably at most 600, e.g. at most 400.

[0055] The number of external operating fluid passages in the bypass channel can be 4 to 1000, preferably 6 to 600, e.g., 8 to 400. It may be advantageous if the direction of extension of the flow disturbance structure changes in the external section.

[0056] It can be advantageous if the direction of extension of the flow disturbance structure changes in the inner section.

[0057] It can be advantageous if the outer section is curved.

[0058] It can be advantageous if the inner section is curved.

[0059] It can be particularly advantageous if the bends of the outer section and the inner section are in opposite directions.

[0060] For example, an extension direction of the flow disturbance structure can change in the opposite direction in the outer section and in the inner section.

[0061] The outer section and the inner section of the flow disturbance structure may be spaced apart from each other.

[0062] Advantageously, the outer section and the inner section of the flow disturbance structure can merge into one another.

[0063] It may be advantageous if the outer section and the inner section merge into one another directly or indirectly, e.g. via an intermediate section.

[0064] The outer section and the inner section can merge directly into one another. For example, an inner section that is bent in one direction can merge directly into an outer section that is bent in a different direction. The curved sections that merge directly into one another can therefore, in particular, be bent in opposite directions.

[0065] It may be advantageous if the outer section and the inner section merge indirectly via the intermediate section. It may be advantageous if the direction of extension of the flow disturbance structure does not change in the intermediate section. The intermediate section can, for example, be straight.

[0066] It may be advantageous if the flow disturbance structure has a pattern of flow disturbance structure elements that repeats several times along an extension direction of the flow disturbance structure.

[0067] It can be particularly advantageous if the flow disturbance structure has a pattern of flow disturbance structure elements that repeats at least three times along the direction of extension of the flow disturbance structure.

[0068] For example, the flow disturbance structure can have a pattern of flow disturbance structure elements that repeats at least ten times along the direction of extension of the flow disturbance structure.

[0069] It can be particularly advantageous if the flow disturbance structure has a pattern of flow disturbance structure elements that repeats a maximum of a thousand times along the direction of extension of the flow disturbance structure.

[0070] For example, the flow disturbance structure may have a pattern of flow disturbance structure elements that repeats a maximum of two hundred times along the direction of extension of the flow disturbance structure.

[0071] It can be particularly advantageous if the flow disturbance structure has a pattern of flow disturbance structure elements that repeats at least three times and at most a thousand times along the direction of extension of the flow disturbance structure.

[0072] For example, the flow disturbance structure may have a pattern of flow disturbance structure elements that repeats at least ten times and at most two hundred times along the direction of extension of the flow disturbance structure.

[0073] The flow disturbance structure elements of the flow disturbance structure can, for example, be sections of the flow disturbance structure. The sections can, for example, comprise outer sections, inner sections, and / or intermediate sections already described herein. It can be advantageous if the repeating pattern of sections comprises the outer section and the inner section.

[0074] Advantageously, the repeating pattern may comprise the outer section and the inner section as well as the intermediate section over which the outer section and the inner section merge into one another.

[0075] Advantageously, the repeating pattern may comprise the outer section and the inner section as well as the intermediate section over which the outer section and the inner section merge into one another, and a further intermediate section into which the inner section merges.

[0076] It may be advantageous if the intermediate section and the further intermediate section run parallel to each other or form an angle of at most 30°, preferably at most 20°, e.g. at most 10°.

[0077] It may be advantageous if the two intermediate sections belonging to successive repetitions of the pattern, and the two merging into an outer section, run parallel to each other or form an angle of no more than 30°, preferably no more than 20°, e.g. no more than 10°.

[0078] It can be advantageous if the flow disturbance structure has a depression.

[0079] It may be advantageous if the recess extends into the flow disturbance structure on an inner side of the flow disturbance structure that faces the operating fluid distribution structure.

[0080] It may be advantageous if the recess extends from an inner side of the flow disturbance structure, which faces the operating fluid distribution structure, between two inner sections to an outer section.

[0081] It may be advantageous if the depression tapers along a depression extension direction, starting from an inner side of the flow disturbance structure, into the flow disturbance structure. It may be advantageous if the depression is one of a plurality of depressions that the flow disturbance structure has, and at least one of the depressions runs in the repeating pattern and / or at least one of the depressions runs between two repeating patterns.

[0082] It may be advantageous if the flow disturbance structure is formed entirely or partially as a structure embossed into the plate element.

[0083] It may be advantageous if, on an inner side of the flow disturbance structure, the inner side of the flow disturbance structure facing the operating fluid distribution structure, the first main surface of the plate element transitions into the flow disturbance structure, wherein a transition length, which is the length of an imaginary line running in the transition of the first main surface into the flow disturbance structure, is at least 150% of the length, e.g., at least 250% of the length, of a shortest path leading through the bypass channel.

[0084] Advantageously, the length of the imaginary line running in the transition of the first main surface into the flow disturbance structure may be at most 5000% of the length, e.g., at most 1500% of the length, of a shortest path leading through the bypass channel.

[0085] In particular, if a bend of the plate element is strong in a region in which it extends into the flow disturbance structure, in particular with a small bending radius or if the plate element extends there in a kink-like manner into the flow disturbance structure, the transition of the first main surface into the flow disturbance structure is readily recognizable.

[0086] Where or when a bend of the plate element is relatively weak in a region where it extends into the flow disturbance structure, the transition of the first main surface into the flow disturbance structure may not be readily apparent. This may be particularly true if the bending radius of the plate element is large there. For example, the transition may be formed by all those locations where, during movement along the first main surface toward the flow disturbance structure, an increasing inclination of the first main surface relative to a main extension plane of the plate element exceeds 10°.

[0087] It may be advantageous if the flow-disturbing structure forms a support structure. The flow-disturbing structure can, in particular, form a support structure onto which an edge zone of a gas diffusion layer can be placed. The statement that an edge zone of a gas diffusion layer can be placed on the support structure can, in particular, mean that, in an electrochemical system constructed using the plate element, the edge zone of a gas diffusion layer can come to rest on the support structure.

[0088] It may be advantageous if, at least in one section of the bypass channel, a support width of the support structure, which can be measured orthogonally to the direction of the bypass channel there along the first main surface, is at least twice as large as an average width of support webs that run within the operating fluid distribution structure between operating fluid distribution channels or operating fluid distribution channel sections. The support width of the support structure, which can be measured along the first main surface, can preferably be at least three times as large, particularly preferably at least four times as large, e.g., at least five times as large, as the average width of the support webs.

[0089] The support width of the support structure measurable along the first main surface can preferably be at most one hundred times as large, particularly preferably at most fifty times as large, e.g. at most thirty times as large, than the average width of the support webs.

[0090] The support width of the support structure, which can be measured along the first main surface, can preferably be three to one hundred times as large, particularly preferably four to fifty times as large, e.g. five to thirty times as large, than the average width of the support webs.

[0091] The support width can, for example, be measured orthogonally to the direction of the bypass channel, from the outer ends of outer sections to the inner ends of inner sections. When measuring the support width of the support structure, all areas of the support structure that form a support zone on which an edge zone of a gas diffusion layer can be applied can be considered. For example, all areas of the support structure that lie in the most elevated quarter of the support structure can be included in the support zone.

[0092] It may be advantageous if the flow disturbance structure is a first flow disturbance structure and the edge of the plate element is a first edge of the plate element, wherein the plate element has a second flow disturbance structure on the first main surface of the plate element between the operating fluid distribution structure and a second edge of the plate element, which is opposite the first edge.

[0093] It may be advantageous if the support structure is a first support structure and the second flow disturbance structure forms a second support structure.

[0094] It may be advantageous if the fluid barrier structure is a first fluid barrier structure and the plate element comprises: a second fluid barrier structure on the first main surface of the plate element, wherein a portion of the second fluid barrier structure is located between the second flow disturbance structure and the second edge of the plate element.

[0095] It may be advantageous if the bypass channel is a first bypass channel through which a first portion of an operating fluid can flow past the operating fluid distribution structure, wherein the plate element has the following: a second bypass channel through which a second portion of an operating fluid can flow past the operating fluid distribution structure, wherein a portion of the second bypass channel or the entire second bypass channel extends between the operating fluid distribution structure and the second fluid barrier structure.

[0096] It may be advantageous if the second flow disturbance structure or a portion of the second flow disturbance structure is located between the operating fluid distribution structure and the second fluid barrier structure, for example in the second bypass channel between the operating fluid distribution structure and the second fluid barrier structure; and / or is spaced apart from the operating fluid distribution structure, for example from a second distribution structure outer wall of the operating fluid distribution structure, which is located on the operating fluid distribution structure opposite the distribution structure outer wall; and / or is spaced apart from the second fluid barrier structure, for example from a barrier inner wall of the second fluid barrier structure.

[0097] It may be advantageous if the internal operating fluid passage is a first internal operating fluid passage and the plate element has the following: a second internal operating fluid passage, e.g., operating fluid throttling passage, between the operating fluid distribution structure and the second flow disturbance structure, for example, between the second distribution structure outer wall and the second flow disturbance structure.

[0098] It may be advantageous if the external operating fluid passage is a first external operating fluid passage, and the plate element comprises a second external operating fluid passage, e.g., a second operating fluid throttling passage, between the second flow disruption structure and the second fluid barrier structure, for example, between the second flow disruption structure and a second barrier inner wall, which is a barrier inner wall of the second fluid barrier structure. It may be advantageous if the second flow disruption structure comprises an external section and an internal section, wherein the external section is closer to the second fluid barrier structure than the internal section, and the internal section is closer to the operating fluid distribution structure than the external section.

[0099] It may be advantageous if: the second internal operating fluid passage, e.g., the second operating fluid throttling passage, is located between the operating fluid distribution structure and the internal portion of the second flow disturbance structure, e.g., between the second distribution structure outer wall and the internal portion of the second flow disturbance structure; and / or the second external operating fluid passage, e.g., the second external operating fluid throttling passage, is located between the external portion of the second flow disturbance structure and the second fluid barrier structure, e.g., between the external portion of the second flow disturbance structure and the second barrier inner wall.

[0100] It may be advantageous if an extension direction of the second flow disruption structure changes in the outer section; and / or an extension direction of the second flow disruption structure changes in the inner section; and / or the outer section is bent; and / or the inner section is bent; wherein the bends of the outer section and the inner section in the second flow disruption structure can be in opposite directions. The second flow disruption structure can also have further features of the first flow disruption structure, e.g. those described in connection with intermediate sections, in connection with repeating patterns, in connection with one or more depressions and / or in connection with a transition length for the first flow disruption structure.

[0101] The problem is solved by the bipolar plate according to the relevant independent claim.

[0102] The bipolar plate has at least one plate element. The plate element can, in particular, be a bipolar plate element. Preferably, the bipolar plate has at least one plate element according to the invention described herein, in particular a bipolar plate element according to the invention described herein.

[0103] The bipolar plate may comprise or consist of a single plate element, in particular a bipolar plate element. The single plate element, in particular a bipolar plate element, may preferably be a plate element according to the invention described herein, in particular a bipolar plate element according to the invention described herein.

[0104] It may be advantageous if the bipolar plate comprises the plate element, in particular the bipolar plate element, advantageously the plate element according to the invention described herein, e.g. the bipolar plate element according to the invention described herein, and a second plate element, in particular a bipolar plate element.

[0105] It may be advantageous if the second plate element is also a plate element according to the invention described herein, in particular a bipolar plate element according to the invention described herein.

[0106] It may be advantageous if the two plate elements each have their operating fluid distribution structure, flow disturbance structure(s) and / or fluid barrier structure(s) on a first main surface of their two main surfaces; and / or the two first main surfaces of the two plate elements face away from each other and form the two bipolar plate surfaces of the bipolar plate; and / or the two plate elements are connected to each other at their second main surfaces, which may advantageously face each other, and / or are electrically conductively connected to each other, e.g., welded.

[0107] The problem is solved by the plate arrangement, e.g. bipolar plate arrangement, according to the relevant independent claim.

[0108] The plate arrangement may be a plate arrangement for an electrochemical system.

[0109] The plate assembly may be a plate assembly for a fuel cell system.

[0110] The bipolar plate arrangement may be a bipolar plate arrangement for an electrochemical system.

[0111] The bipolar plate assembly may be a bipolar plate assembly for a fuel cell system.

[0112] The plate assembly comprises: a bipolar plate according to the invention as described herein and a gas diffusion layer arranged on one of the bipolar plate surfaces of the bipolar plate.

[0113] The gas diffusion layer is also referred to herein as GDL. The gas diffusion layer can be a gas diffusion layer of a membrane electrode assembly. The membrane electrode assembly is also referred to herein as MEA.

[0114] The membrane-electrode assembly may comprise a membrane with catalyst layers arranged on both surfaces. A gas diffusion layer may be arranged on each of the catalyst layers. The gas diffusion layer comprising the plate arrangement may be one of the two gas diffusion layers of the membrane-electrode assembly.

[0115] It may be advantageous if the edge zone of the gas diffusion layer rests on the support structure; and / or the first edge zone of the gas diffusion layer rests on the first support structure and the second edge zone of the gas diffusion layer rests on the second support structure.

[0116] The first edge zone and the second edge zone of the gas diffusion layer can advantageously be located on the same surface of the gas diffusion layer at opposite edges of the gas diffusion layer.

[0117] It may be advantageous if the first edge zone of the gas diffusion layer rests on the first support structure and the second edge zone of the gas diffusion layer rests on the second support structure, wherein the gas diffusion layer with its first edge zone completely or partially covers the first support structure and / or the gas diffusion layer with its second edge zone completely or partially covers the second support structure, wherein at least one point of the first support structure the first support structure is less covered by the gas diffusion layer than the second support structure at at least one point of the second support structure.

[0118] The gas diffusion layer arranged on one of the bipolar plate surfaces of the bipolar plate can, for example, deviate from a desired position on the bipolar plate surface without this significantly impairing the functionality.

[0119] For example, the first edge zone and the second edge zone of the gas diffusion layer may not be aligned exactly parallel to the opposing edges of the bipolar plate, and / or one of the two edge zones of the gas diffusion layer may be arranged closer to an edge of the bipolar plate than the other of the two edge zones of the gas diffusion layer. In both configurations, the first support structure would be less covered by the gas diffusion layer at at least one location of the first support structure than the second support structure at at least one location of the second support structure.

[0120] For example, the first edge zone of the gas diffusion layer can rest on the first support structure and be pressed onto the depression or onto several depressions of the plurality of depressions of the first support structure and / or be pressed into the depression or into several depressions of the plurality of depressions of the first support structure.

[0121] Alternatively or additionally, the second edge zone of the gas diffusion layer can rest on the second support structure and be pressed onto the depression or onto several depressions of the plurality of depressions of the second support structure and / or be pressed into the depression or into several depressions of the plurality of depressions of the second support structure. This object is achieved by the electrochemical system, e.g., fuel cell system, according to the related independent claim.

[0122] When reference is made herein to an electrochemical system, this may advantageously mean a fuel cell system, an electrolysis system and / or an electrochemical reaction system, for example an electrochemical reactor.

[0123] Preferably, an electrochemical system mentioned herein may be a fuel cell system or an electrolysis system.

[0124] For example, an electrochemical system referred to herein may be a fuel cell system.

[0125] The electrochemical system comprises multiple electrochemical cells. For example, the fuel cell system may comprise multiple fuel cells.

[0126] If the electrochemical system is an electrolysis system, the electrolysis system may have multiple electrolysis cells.

[0127] In a fuel cell system, one operating fluid may be a fuel-containing operating fluid, e.g., an operating fluid containing molecular hydrogen (H2). In a fuel cell system, another operating fluid may be an oxidant-containing operating fluid, in particular, an operating fluid containing molecular oxygen (O2), which may, e.g., be provided entirely or partially from ambient air.

[0128] In an electrolysis system, an operating fluid may be a water-containing operating fluid, e.g., an operating fluid consisting essentially of water. It may contain at least 90 wt% water, e.g., at least 99 wt% water.

[0129] In an electrochemical reaction system, for example, in an electrochemical reactor, one or more products can be formed from one or more reactants, where, for example, at least one of the reactants may be an organic reactant. This can advantageously be accompanied by a change in the oxidation state of at least one atom, e.g., a carbon atom, of at least one reactant, e.g., an organic reactant.

[0130] In the electrochemical system, a bipolar plate, in particular a bipolar plate according to the invention described herein, is arranged between at least two of the electrochemical cells; and / or the electrochemical system comprises a plate arrangement, in particular a plate arrangement according to the invention described herein.

[0131] Of course, features described in connection with an inventive subject matter can also form features of another inventive subject matter described herein. Subject matters according to the invention include, in particular, the plate element, the bipolar plate element, the bipolar plate, the plate arrangement, the bipolar plate arrangement, the electrochemical system, the fuel cell system, the electrolysis system, and the electrochemical reaction system.

[0132] Further preferred features and / or advantages of the invention are the subject of the following description and the drawings of exemplary embodiments.

[0133] The drawings show:

[0134] Fig. 1 : a plate element, wherein the first main surface of the plate element faces the viewer;

[0135] Fig. 2: an enlarged section of Fig. 1 showing a section of a

[0136] bypass channel;

[0137] Fig. 3: an enlarged section of Fig. 2 showing a flow disturbance structure; Fig. 4: a section of a bypass channel of the plate element shown in Fig. 1;

[0138] Fig. 5: a section along the line VV of Fig. 4;

[0139] Fig. 6: a section along the line VI-VI of Fig. 4;

[0140] Fig. 7: a section along the line VII-VII of Fig. 4;

[0141] Fig. 8: another plate element, wherein a first main surface faces the viewer; and

[0142] Fig. 9: an enlarged view of a bypass channel from Fig. 8.

[0143] Identical or functionally equivalent elements are provided with the same reference numerals in all figures.

[0144] Fig. 1 shows a plate element 100. The plate element 100 is a bipolar plate element 102. It is suitable for an electrochemical system, in particular for a fuel cell system.

[0145] The plate element 100 has a first main surface 108 facing the viewer in Fig. 1 and a second main surface 110 facing away from the viewer in Fig. 1. The plate element 100 has an operating fluid distribution structure 104. The operating fluid distribution structure 104 is arranged on the first main surface 108 of the plate element 100. It can serve, in particular, for the planar distribution of an operating fluid 106 on the first main surface 108. The operating fluid distribution structure 104 comprises a plurality of operating fluid distribution channels 112. By way of example, only two of the operating fluid distribution channels 112 are provided with reference numerals in Fig. 1.

[0146] The plate element 100 has a first edge 114 and a second edge 116.

[0147] The plate element 100 has a supply zone 118 through which the operating fluid 106 can be supplied. The plate element 100 has a discharge zone 120 through which a fully or partially used operating fluid can be discharged. The plate element 100 has a distribution zone 122 and a collection zone 124. The operating fluid 106, which can be supplied through the supply zone 118, can be distributed over the entire surface of the first main surface 108 in the distribution zone 122. After at least partial conversion of the operating fluid in an electrochemical system in which the plate element 100 can be used, the operating fluid can be collected in the collection zone 124 and supplied to the discharge zone 120.

[0148] Fig. 2 shows an enlarged section of Fig. 1.

[0149] From Fig. 2, it can be clearly seen that the plate element 100 has a flow disturbance structure 126. The flow disturbance structure 126 is arranged on the first main surface 108 of the plate element 100 between the operating fluid distribution structure 104, of which only an edge-positioned operating fluid distribution channel 112 is shown in Fig. 2, and the edge 114 of the plate element 100.

[0150] Fig. 2 also shows that the plate element 100 shown therein has a fluid barrier structure 128 on the first main surface 108 of the plate element 100. A portion 130 of the fluid barrier structure 128 shown in Fig. 2 is located between the flow disturbance structure 126 and the edge 114 of the plate element 100.

[0151] The plate element 100 may be a metallic plate element 100. The described structures, for example, the operating fluid distribution structure 104, the flow disturbance structure 126, and the fluid barrier structure 128, may be structures introduced by forming, for example, embossed structures.

[0152] Fig. 2 shows that the plate element 100 has a bypass channel 132. A portion 134 of an operating fluid 106 that has not entered the operating fluid distribution structure 104 can flow past the operating fluid distribution structure 104 through the bypass channel 132.

[0153] A portion 136 of the bypass channel 132, shown in Fig. 2, extends between the operating fluid distribution structure 104 and the fluid barrier structure 128.

[0154] In particular, it is clear from Fig. 1 that the entire bypass channel 132 extends between the operating fluid distribution structure 104 and the fluid barrier structure 128. It is clear from Fig. 2 that the portion 138 of the flow disturbance structure 126 shown therein lies between the operating fluid distribution structure 104 and the fluid barrier structure 128. The portion 138 of the flow disturbance structure 126 shown therein lies in the bypass channel 132 between the operating fluid distribution structure 104 and the fluid barrier structure 128.

[0155] Fig. 2 also shows that the portion 138 of the flow disturbance structure 126 shown there is spaced from the operating fluid distribution structure 104. In the example shown there, the operating fluid distribution structure 104 has a distribution structure outer boundary 140 in the form of a distribution structure outer wall 142 on the only operating fluid distribution channel 112 shown. It can be clearly seen from Fig. 2 that the portion 138 of the flow disturbance structure 126 shown there is spaced from the distribution structure outer wall 142 of the operating fluid distribution structure 104.

[0156] It can also be clearly seen from Fig. 2 that the portion 138 of the flow disturbance structure 126 shown there is spaced from the fluid barrier structure 128. The fluid barrier structure 128 has an inner barrier boundary 144 in the form of a barrier inner wall 146. The portion 138 of the flow disturbance structure 126 shown in Fig. 2 is spaced from the inner barrier wall 146 of the fluid barrier structure 128.

[0157] From Fig. 2, it can also be clearly seen that the plate element 100 shown there has an internal operating fluid passage 148 between the operating fluid distribution structure 104 and the flow disturbance structure 126. The internal operating fluid passage 148 is an internal operating fluid throttling passage 150. The internal operating fluid passage 148 is located between the distribution structure outer wall 142 and the flow disturbance structure 126.

[0158] Fig. 2 also shows that the plate element 100 shown therein has an external operating fluid passage 152. The external operating fluid passage 152 is an external operating fluid throttling passage 154. The external operating fluid passage 152 is located between the flow disturbance structure 126 and the barrier inner wall 146 of the fluid barrier structure 128.

[0159] The bypass channel 132 forms a fluid guide path 156. The flow disturbance structure 126 lies in the fluid guide path 156. In the fluid guide path 156, an operating fluid 106 or the portion 134 of the operating fluid 106 can be guided along the first main surface 108 between the operating fluid distribution structure 104 and the fluid barrier structure 128.

[0160] Fig. 3 shows an enlarged section of Fig. 2, in which only a representative part of the flow disturbance structure 126 is shown enlarged.

[0161] From Fig. 3, it can be clearly seen that the flow disturbance structure 126 of the plate element 100 has an outer section 158 and an inner section 160. The outer section 158 is closer to the fluid barrier structure 128 than the inner section 160. The inner section 160 is closer to the operating fluid distribution structure 104 than the outer section 158.

[0162] The internal operating fluid passage 148, shown in Fig. 2, is located between the operating fluid distribution structure 104 and the internal portion 160 of the flow disturbance structure 126. The internal operating fluid passage 148 is located between the distribution structure outer wall 142 and the internal portion 160 of the flow disturbance structure 126.

[0163] The outside operating fluid passage 152, also shown in Fig. 2, is located between the outside portion 158 of the flow disturbance structure 126 and the fluid barrier structure 128. The outside operating fluid passage 152 is located between the outside portion 158 of the flow disturbance structure 126 and the barrier inner wall 146.

[0164] Fig. 2 shows that the plate element 100 shown therein has a plurality of internal operating fluid passages 148 and external operating fluid passages 152, which form constrictions 155, which in the fluid flow direction 157 are each located between zones 159 with larger flow cross sections.

[0165] Several of the internal operating fluid passages 148 are each fluidically connected to one another via intermediate zones 159 with larger flow cross-sections. In the fluid flow direction 157, the fluid can flow through alternating successive internal operating fluid passages 148 and zones 159 with larger flow cross-sections. This can lead to a sequentially increasing throttling, which can ultimately almost completely prevent fluid flow through the bypass channel 132.

[0166] Several of the external operating fluid passages 152 are each fluidically connected to one another via intermediate zones 159 with larger flow cross-sections. In the fluid flow direction 157, the fluid can flow through alternating successive external operating fluid passages 152 and zones 159 with larger flow cross-sections. This can lead to a sequentially increasing throttling, which can ultimately almost completely prevent fluid flow through the bypass channel 132.

[0167] In Fig. 3, an extension direction 162 of the flow disturbance structure 126 is indicated by a partially dashed line which is drawn centrally on the flow disturbance structure 126.

[0168] Fig. 3 clearly shows that the extension direction 162 of the flow disturbance structure 126 shown there as an example changes in the outer section 158 and that the extension direction 162 of the flow disturbance structure 126 also changes in the inner section 160.

[0169] Furthermore, it can be clearly seen in Fig. 3 that the flow disturbance structure 126 shown there as an example has a curved outer section 164 and a curved inner section 166. The bends of the outer section 158, 164 and the inner section 160, 166 are opposite.

[0170] In the flow disturbance structure 126, which is shown as an example in Fig. 3, the outer section 158, 164 and the inner section 160, 166 merge into one another. The outer section 158, 164 and the inner section 160, 166 merge indirectly via an intermediate section 168.

[0171] From a view of Figs. 2 and 3, it becomes clear that the flow disturbance structure 126 has a pattern 170 of flow disturbance structure elements 172 that repeats many times along the extension direction 162. In the case of the example illustrated in Figs. 2 and 3, the flow disturbance structure elements 172 consist of sections 158, 160, 164, 166, and 168.

[0172] The repeating pattern 170 at sections 158, 160, 164, 166, 168 includes the outer section 158, 164 and the inner section 160, 166.

[0173] Figure 3 shows the pattern 170. The sections encompassed by the pattern 170 are outlined with a dotted line. Figure 3 clearly shows that the repeating pattern 170 comprises the outer section 158, 164 and the inner section 160, 166, as well as the intermediate section 168, via which the outer section 158, 164 and the inner section 160, 166 merge into one another, and a further intermediate section 168 into which the inner section merges.

[0174] Fig. 3 also shows that the flow disturbance structure 126 shown therein has a recess 174. The flow disturbance structure 126 shown therein has a plurality of recesses 174.

[0175] The recesses 174 each extend from an inner side 176 of the flow disturbance structure 126, which faces the operating fluid distribution structure 104, into the flow disturbance structure 126.

[0176] The recesses 174 each extend from the inner side 176 of the flow disturbance structure 126, which faces the operating fluid distribution structure 104, between two inner sections 160, 166, to an outer section 158, 164.

[0177] In Fig. 3, one of the recesses 174 is shown hatched. This is intended to illustrate in Fig. 3 that the recesses 174 taper along a recess extension direction 178, each starting from the inner side 176 of the flow disturbance structure 126 into the flow disturbance structure 126.

[0178] It is also clear from Fig. 3 that the flow disturbance structure 126 has a plurality of depressions 174, and that one of the depressions 174 runs in the repeating pattern 170, and that one of the depressions 174 runs between two repeating patterns 170. On an inner side 176 of the flow disturbance structure 126, the inner side 176 of the flow disturbance structure 126 facing the operating fluid distribution structure 104, the first main surface 108 of the plate element 100 merges into the flow disturbance structure 126. A transition length, which is the length of an imaginary line running in the transition of the first main surface 108 into the flow disturbance structure 126, is at least 250% of the length 182 of a shortest path 184 leading through the bypass channel 132 in the plate element shown in Figs. 1 to 3. This is illustrated in Fig. 4. Fig. 4 essentially corresponds to Fig. 2.The imaginary line that runs in the transition from the first main surface 108 to the flow disturbance structure 126 is indicated by a dashed line in Fig. 4. The line follows the contour of the flow disturbance structure on its inner side 176. Accordingly, the line that runs in the transition from the first main surface 108 to the flow disturbance structure 126 is essentially wave-shaped. The dashed line that runs in the transition from the first main surface to the flow disturbance structure 126 is provided with the reference numeral 180 in Fig. 4. In Fig. 4, the length 182 of the shortest path 184 leading through the bypass channel 132 is also indicated by a dashed double arrow.

[0179] From Fig. 4 it is directly apparent that the length of the line 180, which is substantially wave-shaped, is at least 250% of the length 182 of the shortest path 184 leading through the bypass channel 132.

[0180] The flow disturbance structure 126 forms a support structure 186. An edge zone 188 of a gas diffusion layer 190 can rest on the support structure 186. This is illustrated in Figure 4, in which an edge of the gas diffusion layer 190 is shown with a dot-dash line. An edge zone 188 of the gas diffusion layer 190, extending to the edge, rests on the support structure 186.

[0181] The gas diffusion layer 190 can be a gas diffusion layer 190 of a membrane electrode assembly 192. The plate element 100 facing the viewer in Fig. 4, which is a bipolar plate element 102, can form a bipolar plate 194 together with a rear plate element facing away from the viewer. In Fig. 4, three sections VV, VI-VI, and VII-VII are indicated, which are shown in Figs. 5 to 7.

[0182] Fig. 5 shows a section through the bipolar plate 194. The bipolar plate 194 has the plate element 100, which faces the viewer in Figs. 1 to 4. In addition, the bipolar plate 194 shown in Fig. 5 has a second plate element 200. The second plate element 200 is a second bipolar plate element 202. The second plate element 200 can correspond to the first plate element 100 or can differ from the first plate element 100. It can be advantageous if the second plate element 200 also has features that were described in connection with the plate element 100, in particular with reference to Figs. 1 to 4.

[0183] The second plate element 200 also has a first main surface 208 and a second main surface 210.

[0184] For the two plate elements 100 and 200, their operating fluid distribution structure, flow disturbance structure(s), and fluid barrier structure(s) are each provided or formed on the first main surface 108, 208. The two first main surfaces 108, 208 of the two plate elements 100, 200 face away from each other. They form the two bipolar plate surfaces 196 and 198 of the bipolar plate 194. The two plate elements 100, 200 are connected to each other at their second main surfaces 110, 210, which face each other. They are welded, for example, which can form an electrically conductive connection between the two plate elements 100, 200.

[0185] Fig. 5 shows a support structure height 187. The regions of the support structure 186 extending in a raised quarter 189 can be understood as a support zone 191.

[0186] This is also illustrated in Figs. 6 and 7, which show further sectional views.

[0187] From a view of Figs. 6 and 7 together, it is clear that, in the plate element 100, at least in one section 136 of the bypass channel 132, a support width 193 of the support structure 186 is wide, measurable orthogonally to the direction of extension of the bypass channel 132 there along the first main surface 108. The support width 193 is a multiple of an average width of support webs that run within the operating fluid distribution structure 104 between operating fluid distribution channels 112 or operating fluid distribution channel sections. The gas diffusion layer 190 can come to rest on the operating fluid distribution structure 104 on the support webs that run within the operating fluid distribution structure 104 between operating fluid distribution channels 112 or operating fluid distribution channel sections.

[0188] Figs. 6 and 7 do not show a section through the operating fluid distribution structure 104 or through the operating fluid distribution channels 112 running there. However, it can be seen from Fig. 1 that the support webs between the operating fluid distribution channels 112 are considerably narrower than the bypass channels 132 running along the edges 114 and 116 and the flow disturbance structures 126 located therein.

[0189] From Figs. 6 and 7 it is clear that for determining the support width 193, in particular the raised quarter 189 of the support structure 186 located in the support zone can be taken into account.

[0190] A plate assembly, e.g., a bipolar plate assembly, for an electrochemical system, which may be, for example, a fuel cell system, may comprise a bipolar plate 194 and a gas diffusion layer 190. The gas diffusion layer 190 may be arranged on one of the bipolar plate surfaces 196 or 198. This is also clearly shown, for example, in Fig. 4.

[0191] In the plate arrangement, the edge zone 188 of the gas diffusion layer 190 can rest on the support structure 186. For example, a first edge zone 188, indicated in Fig. 4, can rest on the first support structure 186, and a second edge zone of the gas diffusion layer 190, which exists at an opposite edge of the gas diffusion layer 190, can rest on a second support structure. The second support structure can be formed by a second flow disturbance structure arranged on the other side of the operating fluid distribution structure 104, i.e., in an area not shown in Fig. 4.

[0192] It may be advantageous, for example, if at least one location of a support structure is less heavily covered by the gas diffusion layer 190 than another support structure at at least one location of the other support structure. The two support structures mentioned can be formed on both sides of the operating fluid distribution structure 104, with only one of the two support structures being shown in Fig. 4, for example.

[0193] The invention allows gas diffusion layers to deviate from an ideal position in the plate arrangement within certain tolerances. This essentially has no influence on the operating fluid distribution on the main surface against which the respective gas diffusion layer 190 rests.

[0194] In particular, the amount of operating fluid passing through the internal operating fluid passage 148 or through the internal operating fluid passages 148 can be substantially independent of the precise position of an edge of a gas diffusion layer 190 on the corresponding support structure. The same applies to the external operating fluid passage 152.

[0195] The invention can therefore, in particular but not exclusively, enable efficient operation of an electrochemical system, e.g., a fuel cell system, and produce a precise electrochemical system with minimal effort. For example, the bipolar plates and gas diffusion layers or membrane-electrode assemblies incorporated in the electrochemical system, which comprise the gas diffusion layers, require less dimensionally accurate fabrication, allowing production processes to be operated with less waste and requiring less effort to assemble an electrochemical system comprising bipolar plates and gas diffusion layers or membrane-electrode assemblies.

[0196] Figure 8 shows another plate element 100. This is a further bipolar plate element 102. It corresponds to the plate element shown in Figure 1. The only differences are with regard to the design of the flow disturbance structures and the bypass channels. This is particularly evident in Figure 9, which shows an enlarged section of Figure 8.

[0197] Fig. 9 shows that in the further plate element shown in Fig. 8, the flow disruption structure 126 is spaced apart from the operating fluid distribution structure 104 and also from a distribution structure outer wall 142 of the operating fluid distribution structure 104. Unlike the plate element shown in Figs. 1 to 7, the flow disruption structure 126 is not spaced apart from the fluid barrier structure 128. The fluid barrier structure 128 is formed integrally with the flow disruption structure 126. A section 130 of the fluid barrier structure 128 is located between the flow disruption structure 126 and the edge 114 of the plate element. However, the fluid barrier structure 128 and the flow disturbance structure 126 are structural elements of a unitary flow disturbance and fluid barrier structure 125. Consequently, the plate element 100 shown in Figs.8 and 9, the plate element 100 has internal operating fluid passages 148, which are internal operating fluid throttling passages 150. The plate element 100 shown in FIGS. 8 and 9 also has zones 159 with larger flow cross-sections. However, there is no external operating fluid passage 152, and thus no external operating fluid throttling passage 154, which is shown in FIG. 2 for the plate element 100 shown there.

[0198] In the plate element 100 shown in Figs. 8 and 9, the outer portion forms a structural unit with the fluid barrier structure 128. The inner portion 160 is closer to the operating fluid distribution structure 104 than the outer portion, which forms the structural unit with the fluid barrier structure 128.

[0199] List of reference symbols , 200 plate element , 202 bipolar plate element

[0200] Operating fluid distribution structure

[0201] Operating fluid, 208 first main surface, 210 second main surface

[0202] Operating fluid distribution channel, 116 edge

[0203] Feed zone

[0204] Discharge zone

[0205] Distribution zone

[0206] Collection zone

[0207] Flow disturbance and fluid barrier structure

[0208] Flow disturbance structure

[0209] Fluid barrier structure

[0210] Section of the fluid barrier structure

[0211] Bypass channel

[0212] Portion

[0213] Section of the bypass channel

[0214] Proportion of the flow disturbance structure

[0215] Distribution structure outer boundary

[0216] Distribution structure outer wall

[0217] Barrier interior boundary

[0218] Barrier inner wall inside operating fluid passage inside operating fluid throttling passage outside operating fluid passage outside operating fluid throttling passage

[0219] bottleneck

[0220] Fluid conduction path

[0221] Fluid flow direction outer section

[0222] Zone with larger flow cross-section inner section

[0223] Direction of extension curved outer section curved inner section intermediate section

[0224] Pattern

[0225] Flow disturbance structure element

[0226] recess inside

[0227] Indentation extension direction imaginary line

[0228] length

[0229] Away

[0230] Edition structure

[0231] Support structure height

[0232] peripheral zone sublime quarter

[0233] Gas diffusion layer

[0234] Support zone

[0235] Membrane electrode assembly

[0236] Support width

[0237] Bipolar plate, 198 bipolar plate surface

Claims

Patent claims 1. Plate element (100), in particular a bipolar plate element (102), for an electrochemical system, which may be, for example, a fuel cell system, wherein the plate element (100) has the following: an operating fluid distribution structure (104) on a first of the two main surfaces (108, 110) of the plate element (100), wherein the operating fluid distribution structure (104) comprises at least one operating fluid distribution channel (112), and a flow disturbance structure (126) on the first main surface (108) of the plate element (100) between the operating fluid distribution structure (104) and an edge (114, 116) of the plate element (100).

2. Plate element (100) according to claim 1, characterized in that the plate element (100) comprises: a fluid barrier structure (128) on the first main surface (108) of the plate element (100), wherein a portion (130) of the fluid barrier structure (128) is located between the flow disturbance structure (126) and the edge (114, 116) of the plate element (100).

3. Plate element (100) according to claim 2, characterized in that the plate element (100) comprises: a bypass channel (132) through which a portion (134) of an operating fluid (106) can flow past the operating fluid distribution structure (104), wherein a portion (136) of the bypass channel (132) or the entire bypass channel (132) extends between the operating fluid distribution structure (104) and the fluid barrier structure (128).

4. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) or a portion (138) of the flow disturbance structure lies between the operating fluid distribution structure (104) and the fluid barrier structure (128), for example in the bypass channel (132) between the operating fluid distribution structure (104) and the fluid barrier structure (128); and / or is spaced apart from the operating fluid distribution structure (104), for example, is spaced apart from a distribution structure outer wall (142) of the operating fluid distribution structure (104); and / or is spaced apart from the fluid barrier structure (128), for example, is spaced apart from a barrier inner wall (146) of the fluid barrier structure (128).

5. Plate element (100) according to one of the preceding claims, characterized in that the plate element (100) has the following: an internal operating fluid passage (148), e.g., an operating fluid throttling passage (150), between the operating fluid distribution structure (104) and the flow disturbance structure (126), for example, between the distribution structure outer wall (142) and the flow disturbance structure (126); and / or an external operating fluid passage (152), e.g., an operating fluid throttling passage (154), between the flow disturbance structure (126) and the fluid barrier structure (128), for example, between the flow disturbance structure (126) and the barrier inner wall (146).

6. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) has an outer section (158) and an inner section (160), wherein the outer section (158) is closer to the fluid barrier structure (128) than the inner section (160) and the inner section (160) is closer to the operating fluid distribution structure (104) than the outer section (158), wherein it can be advantageous if the inner side operating fluid passage (148), e.g. operating fluid throttling passage (150), is arranged between the operating fluid distribution structure (104) and the inner section (160) of the flow disturbance structure (126), for example between the distribution structure outer wall (142) and the inner section (160) of the flow disturbance structure (126); and / or the outer-side operating fluid passage (152), e.g. operating fluid throttling passage (154), is located between the outer section of the flow disturbance structure (126) and the fluid barrier structure (128), for example between the outer section (158) of the flow disturbance structure (126) and the barrier inner wall (146).

7. Plate element (100) according to claim 6, characterized in that an extension direction (162) of the flow disturbance structure (126) changes in the outer section (158); and / or an extension direction (162) of the flow disturbance structure (126) changes in the inner section (160); and / or the outer section (158) is bent; and / or the inner section (160) is bent; wherein the bends of the outer section (158) and the inner section (160) can be in opposite directions.

8. Plate element (100) according to claim 6 or 7, characterized in that the outer section (158) and the inner section (160) merge into one another directly or indirectly, e.g. via an intermediate section (168).

9. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) is a multiplying, for example at least three times, along an extension direction (162) of the flow disturbance structure (126). e.g. at least ten times, repeating pattern (170) of flow disturbance structural elements (172), e.g. sections (158, 160, 164, 166, 168).

10. Plate element (100) according to claim 9, characterized in that the repeating pattern (170) comprises the outer section (158, 164) and the inner section (160, 166) in sections, wherein the repeating pattern (170) can advantageously comprise the outer section (158, 164) and the inner section (160, 166) as well as the intermediate section (168) via which the outer section (158, 164) and the inner section (160, 166) merge into one another, wherein the repeating pattern (170) can advantageously comprise the outer section (158, 164) and the inner section (160, 166) as well as the intermediate section (168) via which the outer section (158, 164) and the inner section (160, 166) merge into one another, and a further Intermediate section (168) into which the inner section (160, 166) merges.

11. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) has a recess (174), wherein it may be advantageous if the recess (174) extends from an inner side (176) of the flow disturbance structure (126), which inner side faces the operating fluid distribution structure (104), into the flow disturbance structure (126); and / or the recess (174) extends from an inner side (176) of the flow disturbance structure (126), which faces the operating fluid distribution structure (104), between two inner sections (160, 166) through to an outer section (158, 164), and / or the recess (174) tapers along a recess extension direction (178) starting from an inner side (176) of the flow disturbance structure (126) into the flow disturbance structure (126); and / or the depression (174) is one depression (174) of a plurality of depressions (174) having the flow disturbance structure (126), and at least one of the depressions (174) extends in the repeating pattern (170) and / or at least one of the depressions (174) extends between two repeating patterns (170).

12. Plate element (100) according to one of claims 3 to 11, characterized in that on an inner side (176) of the flow disturbance structure (126), wherein the inner side (176) of the flow disturbance structure (126) faces the operating fluid distribution structure (104), the first main surface (108) of the plate element (100) transitions into the flow disturbance structure (126), wherein a transition length, which is the length (182) of an imaginary line (180) running in the transition of the first main surface (108) into the flow disturbance structure (126), is at least 150% of the length (182), e.g. at least 250% of the length (182), of a shortest path (184) leading through the bypass channel (132).

13. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) forms a support structure (186), in particular a support structure (186) on which an edge zone (188) of a gas diffusion layer (190) can be placed.

14. Plate element (100) according to claim 13, characterized in that at least in one section (136) of the bypass channel (132), a support width (193) of the support structure (186) measurable orthogonally to the direction of extension of the bypass channel (132) there along the first main surface (108) is at least twice as large, e.g. at least five times as large, as an average width of support webs which run within the operating fluid distribution structure (104) between operating fluid distribution channels (112) or operating fluid distribution channel sections.

15. Plate element (100) according to one of the preceding claims, characterized in that the flow disturbance structure (126) is a first flow disturbance structure (126) and the edge (114, 116) of the plate element (100) is a first edge (114) of the plate element (100), wherein the plate element (100) has a second flow disturbance structure (126) on the first main surface (108) of the plate element (100) between the operating fluid distribution structure (104) and a second edge (116) of the plate element, which is opposite the first edge (114).

16. Plate element (100) according to claim 15, characterized in that the support structure (186) is a first support structure (186) and the second flow disturbance structure (126) forms a second support structure (186).

17. Bipolar plate (194) comprising at least one plate element (100), in particular bipolar plate element (102), e.g. according to one of the preceding claims.

18. Bipolar plate (194) according to claim 17, characterized in that the bipolar plate (194) has the plate element (100), in particular the bipolar plate element (102), according to one of claims 1 to 16 and has a second plate element (200), in particular bipolar plate element (202), wherein it can be advantageous if the second plate element (200) is also a plate element (200), in particular bipolar plate element (202), according to one of claims 1 to 16.

19. Bipolar plate (194) according to claim 18, characterized in that the two plate elements (100, 200) each have their operating fluid distribution structure (104), flow disturbance structure (126) or flow disturbance structures (126), and / or fluid barrier structure (128) or fluid barrier structures (128) on a first main surface (108, 208) of their two main surfaces (108, 110, 208, 210); and / or the two first main surfaces (108, 208) of the two plate elements (100, 200) face away from each other and form the two bipolar plate surfaces (196, 198) of the bipolar plate (194); and / or the two plate elements (100, 200) are connected to one another at their second main surfaces (110, 210), which may advantageously face one another, and / or are electrically conductively connected to one another, e.g. welded.

20. A plate arrangement, e.g., a bipolar plate arrangement, for an electrochemical system, e.g., a fuel cell system, the plate arrangement comprising: a bipolar plate (194), in particular a bipolar plate (194) according to any one of claims 17 to 19, and a gas diffusion layer (190) arranged on one of the bipolar plate surfaces (196, 198) of the bipolar plate (194).

21. Plate arrangement according to claim 20, characterized in that the edge zone (188) of the gas diffusion layer (190) rests on the support structure (186); and / or the first edge zone (188) of the gas diffusion layer (190) rests on the first support structure (186) and the second edge zone (188) of the gas diffusion layer (190) rests on the second support structure (186).

22. Plate arrangement according to claim 21, characterized in that the first edge zone (188) of the gas diffusion layer (190) rests on the first support structure (186) and the second edge zone (188) of the gas diffusion layer (190) rests on the second support structure (186), wherein the gas diffusion layer (190) with its first edge zone (188) completely or partially covers the first support structure (186) and / or the gas diffusion layer (190) with its second edge zone (188) completely or partially covers the second support structure (186), wherein at least one location of the first support structure (186) the first support structure (186) is less heavily covered by the gas diffusion layer (190) than the second support structure (186) at at least one location of the second support structure (186).

23. Plate arrangement according to claim 22, characterized in that the first edge zone (188) of the gas diffusion layer (190) rests on the first support structure (186) and is pressed onto the recess (174) or onto a plurality of recesses (174) of the plurality of recesses (174) of the first support structure (186) and / or is pressed into the recess (174) or into a plurality of recesses (174) of the plurality of recesses (174) of the first support structure (186).

24. An electrochemical system, e.g., a fuel cell system, comprising a plurality of electrochemical cells, e.g., fuel cells, wherein a bipolar plate (194), in particular a bipolar plate (194) according to one of claims 17 to 19, and / or the electrochemical system comprises a plate arrangement according to one of claims 20 to 23.

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