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DE-102024210838-A1 - Separation tool for separating bipolar plates and membrane electrode assemblies

DE102024210838A1DE 102024210838 A1DE102024210838 A1DE 102024210838A1DE-102024210838-A1

Abstract

The invention relates to a cutting tool (10) for separating bipolar plates (101) and membrane electrode assemblies in fuel cells of a fuel cell stack (100), comprising a blade body (12) having a longitudinal axis (16), with two blade sections (18, 20) arranged opposite the longitudinal axis (16), wherein each blade section (18, 20) has a limiting edge (24, 26) on the side facing away from the longitudinal axis (16) with at least one edge section (28, 30, 32, 34), with a blade tip (22), wherein the edge sections (28, 30) of the two blade sections (18, 20) facing the blade tip (22) intersect the longitudinal axis (16).

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 (14)

  1. Separating tool (10) 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, comprising a blade body (12) having a longitudinal axis (16), with two blade sections (18, 20) arranged opposite the longitudinal axis (16), wherein each blade section (18, 20) has a boundary edge (24, 26) on the side facing away from the longitudinal axis (16), each with at least one edge section (28, 30, 32, 34), with a blade tip (22), wherein the edge sections (28, 30) of the two blade sections (18, 20) facing the blade tip (22) intersect the longitudinal axis (16) and the points of intersection (36, 38) have a distance (a) from each other such that one intersection point (36) limits the blade tip (22), and wherein an acute first angle (α) is formed between the longitudinal axis (16) and the edge section (28) limiting the blade tip (22).
  2. Separating tool according to Claim 1 , characterized in that the acute first angle (α) is between 10° and 30°.
  3. Separating tool according to Claim 1 or 2 , characterized in that the blade body (12) has a boundary edge (39) extending in alignment with the longitudinal axis (16) between the two points of intersection (36, 38).
  4. Separating tool according to one of the Claims 1 until 3 , characterized in that an acute second angle (β) is formed between the longitudinal axis (16) and the edge section (30) which is arranged at a distance from the blade tip (22) and which cuts the longitudinal axis (16), and which is preferably the same size as the acute first angle (α).
  5. Separating tool according to one of the Claims 1 until 4 , characterized in that the two blade sections (18, 20) each have a further edge section (32, 34) on the side facing away from the blade tip (22), wherein the two further edge sections (32, 34) are arranged parallel to each other, in particular also parallel to the longitudinal axis (16).
  6. Separating tool according to one of the Claims 1 until 5 , characterized in that the blade tip (22) has chamfers (40, 42) extending at an angle to a central plane (43) of the blade body (12), at least in the area of the edge section (28).
  7. Separating tool according to Claim 6 , characterized in that the chamfers (40, 42) are symmetrical to the median plane (43).
  8. Separating tool according to one of the Claims 1 until 7 , characterized in that the blade body (12) has a length (L) which corresponds to between five and ten times the width (B) of the blade body (12), and that the blade body (12) has a thickness (d) between greater than or equal to 1 mm and less than or equal to 3 mm, preferably between greater than or equal to 1.5 mm and less than or equal to 2 mm.
  9. Separating tool according to one of the Claims 1 until 8 , characterized in that the blade body (12) is made of a sheet of steel.
  10. Separating tool according to one of the Claims 1 until 9 , characterized in that the blade body (12) is dark at least in certain areas, in particular in the area of the blade tip (22).
  11. Separating tool according to Claim 9 or 10 , characterized in that the blade body (12) is provided with a carbon coating (14).
  12. Separating tool according to one of the Claims 1 until 11 , characterized in that the blade body (12) has two through openings (44, 46), in particular bores, which are arranged at a distance from each other when viewed in the direction of the longitudinal axis (16).
  13. Separating device 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 separating tool (10) according to one of the Claims 1 until 12 and an optical detection unit, in particular a camera system for position detection of the cutting tool (10).
  14. Use of a separating tool (10) according to one of the Claims 1 until 12 for separating cell layers (101) of a cell stack (100), in particular bipolar plates (101) and membrane electrode units of a cell stack (100) of an electrochemical cell, preferably of a fuel cell stack (100) of a fuel cell.

Description

Technical field The invention relates to a separation tool for separating bipolar plates and membrane electrode assemblies in fuel cells of a fuel cell stack, which is characterized in particular in connection with an automated separation of the fuel cells by a particularly safe separation process in which damage to the bipolar plates and the membrane electrode assemblies is avoided. State of the art Within the framework of alternative drive concepts, hydrogen drives are known, for example, for commercial vehicles that use fuel cell stacks as part of an energy conversion system from chemical to electrical energy. Such fuel cell stacks typically consist of a large number of fuel cells stacked on top of each other. Each fuel cell, in turn, consists of two bipolar plates and a foil-like membrane electrode assembly arranged between the bipolar plates. Flat sealing elements are arranged between the membrane electrode assembly and the bipolar plates, mechanically connecting and sealing these components. To be able to replace or recycle the components or parts contained in such fuel cell stacks, for example, at the end of their service life or if individual fuel cells of the stack are damaged, it is necessary to separate the stacked components that are connected to each other in the area of the sealing elements. For this reason, corresponding devices are already known in the prior art. An example is described in the EP 1 478 043 A1 It is known to insert a strip-shaped, wedge-shaped separation tool from opposite sides of the fuel cell stack. This tool engages in a gap between two superimposed bipolar plates and separates the bipolar plates by moving the two tools relative to each other. The known separation tool has a length that extends across the entire width of the fuel cells or the aforementioned gap between the bipolar plates. From the US 2020/0373590 A1 Furthermore, separation tools acting on the fuel cell stack from opposite sides are also known, which in plan view are fork-shaped with two projections or prongs spaced apart from each other. Disclosure of the invention The separation tool according to the invention for separating cell layers of a cell stack, in particular bipolar plates and membrane electrode assemblies 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, in particular within the framework of an automated separation of the bipolar plates and membrane electrode assemblies, preferably in conjunction with an image processing system, it enables a particularly safe operation, which avoids damage to the bipolar plates and the membrane electrode assemblies during separation and enables effective, process-reliable and simple separation. Furthermore, the invention relates to a separating device for separating cell layers of a cell stack, in particular bipolar plates and membrane electrode units of a cell stack of an electrochemical cell, preferably a fuel cell stack of a fuel cell, with a separating tool according to the type described above and an optical detection unit, in particular a camera system for position detection of the separating tool. The invention also relates to the use of a separation tool of the type described above for separating cell layers of a cell stack, in particular bipolar plates and membrane electrode units of a cell stack of an electrochemical cell, preferably a fuel cell stack of a fuel cell. 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 using an elongated cutting tool, designed in the manner of a knife, to penetrate with its blade body longitudinally at a defined point in a gap between two superimposed bipolar plates of a fuel cell, the gap being enlarged due to the design of the bipolar plate, and to initially only cut through it. to separate a portion of their width. By moving the tool transversely to a longitudinal axis, the resulting gap between the bipolar plates can then be widened and formed across their entire width. Thus, the tool initially creates a locally confined gap relative to the transverse extent of the bipolar plates. A blade tip formed at an acute angle facilitates the precise penetration of the blade body into the gap between the bipolar plates. In light of the above explanations, a separation tool according to the invention for separating bipolar plates and membrane electrode assemblies in fuel cells of a fuel cell stack, comprising the features of claim 1, therefore has a blade body having a longitudinal axis. Two blade section