DE-102024210840-A1 - Holding device for bipolar plates and membrane electrode assemblies of a fuel cell stack, as well as device and method for separating bipolar plates and membrane electrode assemblies.

DE102024210840A1DE 102024210840 A1DE102024210840 A1DE 102024210840A1DE-102024210840-A1

Abstract

The invention relates to a holding device (10) for bipolar plates (101) and membrane electrode assemblies of a fuel cell stack (100), comprising two holding elements (12, 14) which are configured to receive a bipolar plate (101) or a membrane electrode assembly at an end section (106) of the bipolar plate (101) or the membrane electrode assembly between the holding elements (12, 14), wherein one holding element (14) is configured to be positioned at least sectionally below, and the other holding element (12) is configured to be positioned at least sectionally above the bipolar plate (101) or the membrane electrode assembly.

Inventors

Manuel Beuttler
Ben Keller
Jochen Straehle
Benjamin Neumaier
Guenter Holzhaeuser
Bernd Beutel
Jan Patrick Lerner

Assignees

Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date: 20260513
Application Date: 20241112

Claims (10)

Holding device (10) for cell layers (101) of a cell stack (100), in particular bipolar plates (101) and membrane electrode assemblies of a cell stack (100) of an electrochemical cell, preferably of a fuel cell stack (100) of a fuel cell, with two holding elements (12, 14) which are configured to receive one of the cell layers (101), in particular a bipolar plate (101) or a membrane electrode assembly at an end section (106) of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode assembly between the holding elements (12, 14), wherein one holding element (14) is configured to be positioned at least partially below, and the other holding element (12) is configured to be positioned at least partially above the cell layer (101), in particular the bipolar plate (101) or the membrane electrode assembly, in order to provide a receptacle (30) for the end section (106) of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode assembly between the retaining elements (12, 14), and wherein the retaining device (10) is designed to prevent movement of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode assembly, out of the receptacle (30).
Holding device according to Claim 1 , characterized in that the two retaining elements (12, 14) are designed to prevent the movement of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode unit, from the receptacle (30).
Holding device according to Claim 2 , characterized in that one retaining element (14) has a base section (20) for forming an upper stop for the cell layer (101), in particular the bipolar plate (101) or the membrane electrode unit, and at least one leg (22, 24) extending from the base section (20) towards the other retaining element (12), preferably perpendicularly, to prevent the movement of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode unit, out of the receptacle (30).
Holding device according to Claim 3 , characterized in that the at least one leg (22, 24) with an end section facing away from the base section (20) can be lowered to a position below the plane of the other retaining element (12).
Holding device according to one of the Claims 1 until 4 , characterized in that at least one of the retaining elements (12, 14) is coupled to a drive mechanism (18, 26) which is designed to realize a movement of the retaining element (12, 14) at least in a direction perpendicular to the plane of the cell layer (101), in particular the bipolar plate (101) or the membrane electrode unit.
Holding device according to one of the Claims 1 until 5 , characterized in that one retaining element (14) is U-shaped and is preferably made from a bent sheet metal part.
Holding device according to one of the Claims 1 until 6 , characterized in that the other retaining element (12) is simultaneously designed as a separating element (16) for locally separating one of the cell layers (101), in particular the bipolar plate (101), from the membrane electrode unit.
Holding device according to Claim 7 , characterized in that the other holding element (12) is designed to be movable in all three directions of a Cartesian coordinate system.
Device (1) for separating cell layers (101) of a cell stack (100), in particular bipolar plates (101) and membrane electrode assemblies of a cell stack (100) of an electrochemical cell, preferably of a fuel cell stack (100) of a fuel cell, with a holding device (10) which is preferably configured according to one of the Claims 1 until 8 is formed, and with a preferably strip-shaped separating body (2) which can be positioned below the holding device (10) and is movably arranged in a direction projecting away from the holding device (10) for separating the cell layer (101), in particular the bipolar plates (101) and the membrane electrode units.
Method for separating cell layers (101) of a cell stack (100), in particular bipolar plates (101) and membrane electrode assemblies of a cell stack (100) of an electrochemical cell, preferably of a fuel cell stack (100) of a fuel cell, by means of a device (1) according to Claim 9 , comprising at least the following steps: - forming an initial gap between the cell layer (101), in particular a bipolar plate (101) and a membrane electrode assembly on the side facing the holding device (10); - positioning a holding element (12) of the holding device (10) in the initial gap; - moving the holding element (12) relative to another holding element (14) of the holding device (10) in order to position the cell layers (101), in particular the bipolar plate (101) or the membrane electrode assembly, in the area of a receptacle (30) between the two holding elements (12, 14) and to clamp or fix, if necessary; - Inserting the separating body (2) between the cell layers (101), in particular the bipolar plate (101) and the membrane electrode assembly or between the membrane electrode assembly and the bipolar plate (101) below the retaining elements (12, 14) and moving the separating body (2) in a direction projecting away from the retaining device (10) to preferably completely separate the cell layer (101), in particular the bipolar plate (101), from the membrane electrode assembly arranged below it or the membrane electrode assembly from the bipolar plate (101) arranged below it.

Description

Technical field The invention relates to a holding device for bipolar plates and membrane electrode assemblies of a fuel cell stack, which enables a particularly reliable separation process for fully automated operation. Furthermore, the invention relates to a device and a method for separating bipolar plates and membrane electrode assemblies of a fuel cell stack, in particular by means of a holding device designed according to the invention. State of the art In the context of developing alternative drive concepts, for example for commercial vehicles or other vehicles, fuel cell drives are known that utilize fuel cell stacks as energy converters, transforming chemical energy into electrical energy to provide the necessary drive energy. Such fuel cell stacks consist of a multitude of fuel cells arranged one above the other. Each fuel cell typically comprises two bipolar plates and a membrane electrode assembly (MEA) positioned between them. The MEA is mechanically connected to a bipolar plate via a gasket and sealed against it. If parts of the fuel cell stack are damaged or need to be replaced, it is necessary to separate the components. Especially considering the raw materials contained within the fuel cell stack, recycling the components is sensible and economically viable if an automated separation process is available for the fuel cell stacks, which typically contain up to 400 bipolar plates. Separation devices for separating bipolar plates of a fuel cell stack are already known from the prior art ( EP 1 478 043 A1 , US 2020/0373590 A1 These devices typically feature two separating devices or separating blades that are horizontally movable from opposite sides of the fuel cell stack against the bipolar plates. Because the two separating devices are moved against the fuel cell stack from both sides, equal forces are introduced into the gap between the two bipolar plates from opposite sides. This results in a nearly symmetrical deformation or separation of the upper bipolar plate from the opposite sides. Disclosure of the invention The holding device according to the invention for cell layers of a cell stack, in particular bipolar plates and membrane electrode units of a cell stack of an electrochemical cell, preferably of a fuel cell stack of a fuel cell with the features of claim 1, has the advantage that, particularly in connection with relatively flexible or deformable membrane electrode units and a two-stage separation process starting from one side of the bipolar plates or the membrane electrode units, it enables defined positioning of an already partially separated bipolar plate or membrane electrode unit and thus avoids unwanted movements of the bipolar plate or the membrane electrode unit, which, for example, lead to an uncontrolled separation process through collision with a lower separation tool or to other damage to the system. The cell layers are preferably bipolar plates and/or membrane electrode assemblies. The cell stack is preferably a cell stack or a fuel cell stack. Within the scope of the present invention, an electrochemical cell comprises, in particular, a fuel cell and/or an electrolysis cell and/or a battery cell. It should be noted that the cell stack can also be that of a cooler or heat exchanger without departing from the scope of the present invention. The invention is based on the idea of designing and arranging the holding device in such a way that a partially separated bipolar plate or membrane electrode assembly is held at the already separated area by means of the milled recesses or openings provided in the design of the bipolar plate and the membrane electrode assembly, so that the actual separation of the held bipolar plate or the membrane electrode assembly can be carried out along its entire length using a separation tool, without the bipolar plate or the membrane electrode assembly yielding or slipping due to mechanical forces of the separation process, which could potentially negatively affect or prevent the separation process. In this process, a bipolar plate and a membrane electrode assembly are separated alternately from each other. In light of the above explanations, a holding device according to the invention for cell layers of a cell stack, in particular bipolar plates and membrane electrodes, therefore features Units of a cell stack of an electrochemical cell, preferably a fuel cell stack of a fuel cell with the features of claim 1, comprise two retaining elements configured to receive a bipolar plate or a membrane electrode assembly at an end section of the bipolar plate or the membrane electrode assembly between the retaining elements. Furthermore, one retaining element is configured to be positioned at least partially below, and the other retaining element at least above, the bipolar plate or the membrane electrode assembly to form a receptacle for the end section of the bipolar plate or the membrane electrode assembly. Finally, the retaining device is config