Battery Stack Assembly

Abstract

A battery stack assembly (100) is provided, which includes at least a battery stack body (102) for generating electrical energy having a plurality of unit batteries stacked in a stacking direction (104), first and second end plates (106) sandwiching the battery stack body (102), at least one of the end plates (106) having openings (108, 114) on a side surface (110), and at least one compression element (1) configured to compress the battery stack body (102) in the stacking direction (104) between the first and second end plates (106), the at least one compression element (1) including a first mounting element (8) disposed at a first end (4) and a second mounting element (114) disposed at a second end (6). The band element (2) has a first mounting element (8) and a second mounting element (10) having a first end plate (106) and a second ...

Description

[Technical Field]

[0001] The present invention relates to a battery stack assembly. [Background technology]

[0002] Typically, a cell stack assembly, such as a fuel cell stack, includes a stack body in which multiple unit cells are stacked in a stacking direction. Each unit cell includes at least two plates, so-called flow field plates, which are arranged on top of each other and have a flow field for reactants on one side and a flow field for cooling fluid on the other side. Thus, the flow fields of adjacent plates form channels through which the respective fluids flow.

[0003] To prevent fluid leakage and achieve fluid-tightness in a battery stack, the stack body is compressed in the stacking direction with the aid of a compression element. For example, Patent Document 1 describes a stack assembly in which the stack body is sandwiched between two end plates. Each end plate has an insertion groove with a recess on its side and a fixing plate extending parallel to the outer periphery of the end plate from the bottom of the insertion groove and protruding into the insertion groove. Compression of the stack assembly is achieved by inserting both ends of a fastening band extending along the side of the stack body between the insertion groove of the end plate and the fixing plate, each end of which is T-shaped. However, inserting the fastening band between the insertion groove of the end plate and the fixing plate requires stack compression that exceeds the compression of the completed stack assembly. In other words, the stack body needs to be compressed more during assembly of the battery stack than during normal operation. Therefore, there is a risk of damage to components of the battery stack assembly during installation of the fastening band. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent No. 101466507 Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide a cell stack assembly having an improved compression element for the cell stack assembly that reduces the risk of damaging the cell stack assembly when the compression element is installed. [Means for solving the problem]

[0006] This object is solved by a cell stack assembly according to claim 1.

[0007] A cell stack assembly, particularly a fuel cell stack assembly, is provided below, including a cell stack body for generating electrical energy having a plurality of unit cells stacked at least in a stacking direction, and preferably each unit cell is a unit fuel cell including a bipolar plate and a membrane electrode assembly. The stack assembly further includes first and second end plates sandwiching the cell stack body for generating electrical energy, at least one of the end plates having a side opening, and at least one compression element configured to compress the cell stack body in the stacking direction between the first and second end plates.

[0008] The at least one compression element includes a band element having a first end and a second end, and the at least one compression element includes a first mounting element disposed at the first end and a second mounting element disposed at the second end. The first mounting element is an anchor bolt-like element protruding from the compression element perpendicular to the stacking direction, and the second mounting element is either an anchor bolt-like element protruding from the compression element perpendicular to the stacking direction or a pressure adjusting element configured to adjust the pressure applied by the at least one compression element in the stacking direction. Each anchor bolt-like element is integrally formed with or permanently fixed to the band element, and at least one anchor bolt-like element is inserted into the opening provided in the side of the at least one end plate. This has the advantage of preventing over-compression of the stack assembly during the assembly process. More specifically, the mounting elements can be inserted into the corresponding openings in the end plates by compressing the stack up to the height of the completed stack assembly during the assembly process. This reduces the risk of damage to components of the stack body. Furthermore, because the at least one anchor bolt-like element is permanently fixed to the band element or is integrally formed with the band element, the height of the stack assembly can be maintained over the life of the stack assembly.

[0009] Preferably, the band element has a predetermined length. Preferably, the length is adapted to provide a desired pressure on the stack assembly under operating conditions. This allows the applied pressure to be determined without risking excessive compression of the stack assembly, even when the first and second mounting elements are configured as anchor bolt-like elements. For example, the at least one compression element may be made of sheet metal. Preferably, the anchor bolt-like element is welded, glued, and / or riveted to the band element.

[0010] According to a further embodiment, the anchor bolt-like element and / or the pressure adjusting element comprises a bolt-like element having a circular, rectangular, elliptical, triangular or polygonal cross section, and / or having a block, conical, truncated conical or pyramidal shape, and / or having at least one chamfered edge. Preferably, the opening formed in the at least one end plate has a shape complementary to the bolt-like element. This has the advantage that the position of the bolt-like element can be defined within the opening. Furthermore, the contact area between the opening and the bolt-like element can be increased, which may lead to increased friction between the opening and the bolt-like element, thereby fixing the position of the bolt-like element within the opening.

[0011] Furthermore, the anchor bolt-like element includes at least one position fixing element configured to fix the position of the anchor bolt-like element, thereby reducing the risk of the anchor bolt-like element becoming detached from the end plate due to vibrations and / or other external forces.

[0012] Preferably, the anchor bolt-like element includes a through-hole, the longitudinal axis of which is perpendicular to the stacking direction, configured to receive and / or interact with the positional fixing element, such that the positional fixing element can be inserted through the through-hole. For example, the positional fixing element may be permanently fixed in the opening in the end plate, or the anchor bolt-like element may be attached to the positional fixing element and fixed in place by suitable means such as a nut, adhesive, and / or welding. Alternatively, the positional fixing element may be inserted through the through-hole in the anchor bolt-like element and fixed to the end plate.

[0013] According to a further embodiment, the pressure adjustment element includes a tension element configured to apply tension in a direction parallel to the stacking direction. Preferably, the tension element is further configured to continuously adjust the pressure applied in the stacking direction. In this manner, the tension element can continuously increase or decrease the pressure applied to the battery stack assembly. Furthermore, the pressure adjustment element may include a through hole, the longitudinal axis of which is parallel to the stacking direction, and the through hole is configured to accommodate and / or interact with the tension element.

[0014] Preferably, the position fixing element and / or the tensioning element is a bolt or a screw.

[0015] According to a further embodiment, the pressure adjusting element includes a loop formed at the second end of the band element by folding the band element back on itself and fastening the folded end to the band element, and the bolt-like element having the through hole is fastened within the loop. For example, the folded end of the band element may be welded, screwed, bolted, riveted, and / or glued to the remaining band element. The bolt-like element may be disposed within the loop and fastened to the band element. Furthermore, the band element may include an opening, such as a slot or slot, so that the bolt-like element remains at least partially accessible even after being fastened within the loop of the band element. For example, the bolt-like element may be welded, screwed, bolted, riveted, and / or glued to the loop.

[0016] Further preferred embodiments are defined in the description and drawings as well as in the dependent claims, in which respect an element described or shown in combination with other elements may also be present alone or in combination with other elements without departing from the scope of protection.

[0017] Preferred embodiments of the invention will now be described with reference to the drawings, which are for illustrative purposes only and are not intended to limit the scope of protection, which is defined solely by the appended claims. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view of a compression element according to the first embodiment. [Figure 2] FIG. 2 is an exploded side view of the cell stack assembly with the compression element of FIG. 1. [Figure 3] FIG. 10 is a perspective view of a compression element according to a second embodiment. [Figure 4] FIG. 4 is an exploded side view of the cell stack assembly with the compression element of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] In the following, identical or similarly functioning elements are designated with the same reference numerals.

[0020] FIG. 1 shows a compression element 1 according to a first embodiment. The compression element 1 has a band element 2 with a first end 4 and a second end 6. First and second attachment elements 8, 10 are disposed at the first and second ends 4, 6, respectively. In FIG. 1, both attachment elements 8, 10 are anchor bolt-like elements 12 that protrude from the compression element 1 perpendicular to the longitudinal direction of the band element 2. As can be seen in FIG. 2, the longitudinal direction of the band element 2 is parallel to the stacking direction 104 of the battery stack assembly 100, so when placed in the battery stack assembly 100, the anchor bolt-like elements 8, 10 protrude from the compression element 1 perpendicular to the stacking direction 104.

[0021] The band element 2 has a predetermined length and is made of metal plate. Each anchor bolt-like element 12 is permanently fixed to the band element by welding and is configured to be inserted into an opening (FIG. 2) provided in the side of the cell stack assembly 100. However, the anchor bolt-like elements 12 can also be glued and / or riveted to the band element 2, or even formed integrally with the band element 2, for example in a casting process.

[0022] Anchor bolt-like element 12 includes a bolt-like element 14 having a cylindrical shape with a chamfered upper end 16. Alternatively, bolt-like element 14 may have any other suitable shape that can be inserted into an opening. For example, bolt-like element 14 may have a circular, rectangular, oval, triangular, or polygonal cross-section, and / or may have a block, conical, truncated conical, or pyramidal shape.

[0023] FIG. 2 shows an exploded side view of a cell stack assembly 100. The cell stack assembly 100 may be a fuel cell stack assembly. As can be seen in FIG. 2, the cell stack assembly 100 includes an electrical energy-producing cell stack body 102 having a plurality of unit cells stacked in a stacking direction 104. The stack assembly 102 also includes first and second end plates 106 that sandwich the electrical energy-producing cell stack body 102. The electrical energy-producing cell stack body 102 is sandwiched between two terminal plates 118 that are insulated from the end plates 106 by two insulating plates 120.

[0024] 2, both end plates 106 have openings 108 on each side 110 with a normal vector perpendicular to the stacking direction 104. The openings 108 have a shape complementary to the bolt-like elements 14. This has the advantage that the contact area between the bolt-like elements 14 and the openings 108 is increased.

[0025] When the stack assembly 100 is assembled, the stack is compressed to a predetermined height, after which the bolt-like elements 14 of the mounting elements 8, 10 are inserted into corresponding openings 108 in the end plate 106. To account for variations in the dimensions of the components of the stack assembly 100, for example due to manufacturing tolerances, the stack assembly 100 further includes two spring elements 122 and a compression plate 124. The compression plate 124 is positioned between the upper insulating plate 114 and the upper end plate 106, and the spring elements are positioned between the compression plate 124 and the end plate 106. Because each anchor bolt-like element 12 is permanently fixed to the band element 2 by welding, the positions of the mounting elements 8, 10 are fixed, thereby maintaining the compression of the stack, and therefore the stack height, throughout the life of the stack assembly 100.

[0026] To fix the position of the mounting elements 8, 10, both anchor bolt-like elements 12 include a through hole 18 through which a screw 20 is inserted, which screws into a thread 112 provided in the opening 108 of the end plate 106. The through hole 18, the screw 20, and the thread 112 thus form a position fixing element configured to fix the position of the mounting elements 8, 10. Alternatively, the position fixing element may be a bolt permanently fixed in the opening 108 of the end plate 106, and the anchor bolt-like element 12 may be attached to the position fixing element and fixed in this position by suitable means such as a nut, adhesive, and / or welding.

[0027] FIG. 3 shows a compression element 1 according to a second embodiment. The compression element has a band element 2 with a first end 4 and a second end 6. First and second mounting elements 8, 10 are disposed at the first and second ends, respectively. In FIG. 3, the first mounting element 8 is the anchor bolt-like element 12 described above. The second mounting element 10 is a pressure adjusting element 24 configured to adjust the pressure exerted by the compression element 1 in the stacking direction 104 (FIG. 4).

[0028] The pressure adjustment element 24 includes a bolt-like element 26 having a cylindrical shape. Alternatively, the bolt-like element 26 may have any other suitable shape. For example, the bolt-like element 26 may have a circular, rectangular, oval, triangular, or polygonal cross-section, and / or may have a block, conical, truncated conical, or pyramidal shape, and / or may have at least one chamfered edge. Furthermore, the pressure adjustment element 24 includes a loop 28 formed at the second end 6 of the compression element 1 by folding the band element 2 back on itself and securing the folded end to the band element 2. For example, the folded end may be welded, screwed, bolted, riveted, and / or glued. The bolt-like element 26 is disposed within the loop 28 and secured to the band element 2 by welding. In this case, the band element 2 includes an elongated hole 30 so that the bolt-like element 26 is at least partially accessible after the bolt-like element 28 is welded to the band element 2.

[0029] FIG. 4 shows an exploded side view of a cell stack assembly 100. The cell stack assembly 100 may be a fuel cell stack assembly. As can be seen in FIG. 4 , the cell stack assembly 100 includes an electric energy-producing cell stack body 102 having a plurality of unit cells stacked in a stacking direction 104. The stack assembly 102 also includes first and second end plates 106 that sandwich the electric energy-producing cell stack body 102. The electric energy-producing cell stack body 102 is sandwiched between two terminal plates 118 that are insulated from the end plates 106 by two insulating plates 120. To account for dimensional variations in components of the stack assembly 100 due to, for example, manufacturing tolerances, the stack assembly 100 further includes two spring elements 122 and a compression plate 124. The compression plate 124 is disposed between the upper insulating plate 114 and the upper end plate 106, and the spring element is disposed between the compression plate 124 and the end plate 106.

[0030] 4, one end plate 106 has an opening 108 having a shape complementary to the bolt-like element 14 of the first mounting element 8, as described above. The other end plate 106 has an opening 114 suitable for receiving the pressure adjusting element 24 of the second mounting element 10. Furthermore, the other end plate 106 includes a through hole 116 through which a tensioning element 32, such as a screw or bolt, can pass, which tensioning element 32 is configured to cooperate with the hole 34 of the bolt-like element 26.

[0031] When the stack assembly 100 is assembled, the first mounting element 8 with the anchor bolt-like element 12 is inserted into the corresponding opening 108. The other end can be aligned with the opening 114 in the other end plate 106, and the tensioning element 32 can then be tightened to the appropriate torque, thereby adjusting the pressure applied to the stack 100 while maintaining a consistent amount of stiffness.

[0032] The tension element 32 is configured to apply tension in a direction parallel to the stacking direction 104. By tightening or loosening the tension element 32, the pressure applied by the compression element 1 in the stacking direction 104 can be continuously adjusted. Thus, the tension element 32 can continuously increase or decrease the pressure applied to the battery stack assembly 100. The holes 34 may be configured as through holes, in which case the longitudinal axis of the through holes is parallel to the stacking direction 104.

[0033] In summary, the described compression elements provide compressive retention that can be maintained throughout the life of the battery stack assembly. More specifically, embodiments with two anchor bolt-like elements provide similar stiffness to threaded rods while significantly reducing space and weight. Furthermore, because the length is fully predetermined, the risk of tilting, force imbalance, and / or other assembly-related issues is eliminated or at least reduced. Furthermore, embodiments with pressure adjustment elements provide sufficient stiffness while remaining adjustable to accommodate variations in battery stack height.

[0034] Both described embodiments have the advantage that the compression elements are located only on the sides of the cell stack assembly, leaving the top and bottom surfaces of the cell stack assembly free to be used for other functions. [Explanation of symbols]

[0035] 1 compression factor 2 Band Elements 4 First end 6 Second end 8 First Mounting Element 10 second mounting element 12 Anchor bolt-like element 14 Bolt-like elements 16 Top 18 Through holes 20 Position fixing elements 24 Pressure Regulating Element 26 bolt-like elements 28 Loops 30 slots 32 Tension Elements 34 Through hole 100 Battery stack assembly 102 Battery stack body for generating electrical energy 104 Lamination direction 106 End Plate 108 Opening 110 Side 112 threads 114 Opening 116 Through hole 118 Terminal Plate 120 Insulation Plate 122 Spring Elements 124 compression plate

Claims

1. A cell stack assembly (100), in particular a fuel cell stack assembly, comprising at least A cell stack body (102) for generating electric energy having a plurality of unit cells stacked in a stacking direction (104), each unit cell preferably being a unit fuel cell including a bipolar plate and a membrane electrode assembly; first and second end plates (106) sandwiching the electric energy generating cell stack body (102), at least one of the end plates (106) having an opening (108, 114) in a side surface (110); and at least one compression element (1) configured to compress the electric energy generating battery stack body (102) in the stacking direction (104) between the first and second end plates (106), The at least one compression element (1) includes a band element (2) having a first end (4) and a second end (6), and the at least one compression element (1) includes a first mounting element (8) arranged at the first end (4) and a second mounting element (10) arranged at the second end (6), the first mounting element (8) being an anchor bolt-like element (12) protruding from the compression element (1) perpendicular to the stacking direction (104), and the second mounting element (10) being an anchor bolt-like element protruding from the compression element (1) perpendicular to the stacking direction (104). a pressure adjusting element (24) configured to adjust the pressure applied in the stacking direction (104) by the at least one compression element (1), wherein each anchor bolt-like element (12) is formed integrally with the band element (2) or permanently fixed to the band element (2), and at least one anchor bolt-like element (12) is inserted into the opening (108) provided in the side surface (110) of the at least one end plate (106).

2. The cell stack assembly (100) of claim 1, wherein the band element (2) has a predetermined length.

3. 3. The battery stack assembly (100) of claim 1 or 2, wherein the anchor bolt-like element (12) and / or the pressure adjustment element (24) comprise a bolt-like element (14, 26), and the bolt-like element (14, 26) has a circular, rectangular, elliptical, triangular, or polygonal cross section, and / or has a block, conical, truncated conical, or pyramidal shape, and / or has at least one chamfered edge.

4. 4. The cell stack assembly (100) of claim 3, wherein the opening (108, 114) formed in the at least one end plate (106) has a shape complementary to the bolt-like element (14, 26).

5. 5. The battery stack assembly (100) according to claim 1, wherein the anchor bolt-like element (12) includes at least one position fixing element (20) configured to fix the position of the mounting element (8, 10) within the opening (108, 114).

6. 6. The battery stack assembly (100) of claim 5, wherein the anchor bolt-like element (12) includes a through hole (18), the longitudinal axis of the through hole (18) being perpendicular to the stacking direction (104), and the through hole (18) is configured to receive and / or interact with the position fixing element (20).

7. The battery stack assembly (100) of any one of claims 1 to 6, wherein the pressure adjustment element (24) comprises a tension element configured to apply tension in a direction parallel to the stacking direction (104).

8. 8. The battery stack assembly (100) of claim 7, wherein the pressure adjustment element (24) includes a through hole (34), a longitudinal axis of the through hole (34) is parallel to the stacking direction (104), and the through hole (34) is configured to accommodate and / or interact with the tension element (32).

9. 9. The battery stack assembly according to claim 8, wherein the pressure adjustment element includes a loop formed at the second end of the band element by folding the band element back onto itself and fastening the folded end to the band element, and the bolt-like element having the through hole is fastened within the loop.

10. The cell stack assembly (100) according to any one of claims 5 to 9, wherein the position fixing element (20) and / or the tension element (32) are bolts or screws.

11. The cell stack assembly (100) according to any of the preceding claims, wherein the at least one compression element (1) is made of sheet metal.

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