Electrochemical device

Abstract

An electrochemical device includes at least one housing (10A) for a stack (24) of sheets of an electrochemical device forming material that includes at least one sheet of a first type, at least one sheet of a second type, and at least one separator sheet between the two types of sheets, the housing including a plurality of components including a first component (12A) and a second component (14), the components being joined to each other using welding, hemming, crimping, or punch crimping to form an internal volume for accommodating the stack (24).

Description

Technical Field

[0001] The present invention relates to an electrochemical device.

Background Art

[0002] With the increasing use of renewable energy sources, electrochemical devices, i.e., devices that use electrodes and / or membranes in an electrolyte to deliver and / or store electrical energy such as batteries, have gathered interest in a wide range or area. For this reason, sheets of electrochemical materials such as electrode sheets and separator sheets are placed within a housing or casing. Thus, the way in which such a housing is formed is also of interest.

[0003] Such housings are today typically made of flexible or rigid parts in order to protect the interior of the housing from moisture and prevent electrolyte leakage. Common cell formats include pouch housings, rigid cylindrical and prismatic cans. Rigid cell housings have the advantage of being easier to integrate into modules or packs and have a higher level of safety for withstanding internal gas generation, expansion, and external mechanical effects. The additional safety of a rigid structure comes with higher manufacturing complexity and cost.

[0004] In addition, many cell chemistries require compression of the cells when assembled into modules or packs. This is an inaccurate method and results in a complex and failure-prone system, and due to the inaccurate compression conditions, leads to low or unpredictable aging behavior of the entire module or a single cell within the module.

[0005] However, it is interesting to improve the cell housing by providing a rigid or semi-rigid housing that can improve cell life and be easily manufactured.

[0006] One type of housing is known from U.S. Patent No. 9,831,474, and a battery cell including an electrode assembly of a cathode / separator / anode structure is impregnated with an electrolyte and mounted in a battery case made of aluminum or an aluminum alloy. Further, an alumina coating layer is applied to at least a part of the outer surface of the battery case by anodization.

[0007] It is important to improve the method of realizing an electrochemical device such as a stack of sheets having an electrochemical device forming material, and such a stack can be used in a battery cell and / or a fuel cell. SUMMARY OF THE INVENTION

[0008] One object of the present invention is to provide an improved electrochemical device that is easier to manufacture.

[0009] This object is achieved according to a first aspect by an electrochemical device comprising at least one housing for a stack of sheets of an electrochemical device forming material, the electrochemical device comprising at least one sheet of a first type of electrode, at least one sheet of a second type of electrode, and at least one separator sheet between said sheets of the two types of electrodes, the housing comprising a plurality of parts including a first part and a second part, the parts being joined to each other using welding, hemming, crimping, or punch crimping to form an internal volume for accommodating the stack.

[0010] The first and second parts may each have a first edge, and the first edge of the first part may be joined to the first edge of the second part to form a first mechanical connection. The first edge of the first part may be further folded around the first edge of the second part, or vice versa.

[0011] The plurality of parts can further include a third part including a first edge, and the second part can include a second edge. In this case, the first edge of the third part may be further joined to the second edge of the second part to form a second mechanical connection, the first edge of the third part may be further folded around the second edge of the second part, or vice versa.

[0012] Furthermore, a sealant may be present between the edges of at least one mechanical connection.

[0013] The housing may comprise an upper part and a bottom part separated by at least one side wall.

[0014] The stack may have a first end with a bottom sheet, and the first end faces the bottom of the housing. The stack may also have a second end with an upper sheet, and the second end faces the upper part of the housing.

[0015] The upper part, the bottom part, and at least one side wall may be made of a metallic material, and the metallic material may be coated with an electrically insulating material on the surface of the metallic material facing the internal volume. Alternatively, at least one wall, and optionally the lid and the bottom, may also be made of polymer.

[0016] The stack may be arranged within the internal volume. In this case, the stack may be compressed by a pressure applied through the upper and bottom parts of the housing, or through a first side wall and another opposite side wall. This may be achieved by the height of the housing in the axial direction of the stack being smaller than the original stack height, where the original stack height is the stack height before the stack is arranged within the internal volume. The stack is compressed by pressing the upper part or the first side wall axially towards the bottom part or the other side wall. Naturally, additionally or alternatively, the bottom part or the other side wall can be pressed towards the upper part or the first side wall. In this case, the compression operation is started before the parts are joined to each other.

[0017] The housing may further comprise at least one flexible compression element. The flexible compression element may be provided outside at least one side wall. Alternatively, each of the top and bottom may be equipped with a flexible compression element.

[0018] The bottom and / or top of the housing may further be corrugated. Also, there may be a corrugation-conforming element within the internal volume, which flattens grooves on the inner surfaces of the bottom and / or lid facing the stack so that the corrugation does not change the shape of the sheets of the stack during compression.

[0019] The housing may also comprise at least one pretensioning element, and each pretensioning element may be provided at one end of the stack and face the upper or lower sheet of the stack.

[0020] At least one pretensioning element may comprise an internal pretensioning element within the internal volume disposed between the stack and the top or bottom of the housing. There may additionally be a coupling element between the top or bottom of the housing and the internal pretensioning element. This coupling element may be realized as an internal adhesive or a bonding gap filler.

[0021] At least one pretensioning element may additionally or alternatively comprise an external pretensioning element provided as the top or bottom of the housing. In this case, there may be a foam element on the external pretensioning element in a direction away from the stack.

[0022] At least one pretensioning element may be concave with a focus. In this case, the pretensioning element may be additionally disposed between the stack and the focus.

[0023] The housing can also be provided with at least one venting element in the top, bottom, or at least one wall.

[0024] The housing may further comprise a first electrical connection to an electrode of the first type and a second electrical connection to an electrode of the second type.

[0025] The first and second electrical connections may be provided via a first mechanical connection. The first electrical connection may be provided, for example, between the first edges of the first and second components at the side wall of a second component provided on one side of the stack, and the second electrical connection may be provided between the first edges of the first and second components at another opposite side wall of the second component on the opposite side of the stack.

[0026] Alternatively, one electrical connection may be provided through the side wall of the housing, and the other electrical connection may be provided through the opposite side wall of the housing. As yet another alternative, one electrical connection may be provided through the top of the housing, and the other may be provided through the bottom of the housing. Both electrical connections may additionally be provided through the same surface. Thus, they may be provided through the top, the bottom, or the same side wall.

[0027] At least one electrical connection may further comprise a tab extending from inside the housing to the outside of the housing, the tab comprising a conductor surrounded by an insulator.

[0028] The electrochemical device may further comprise two or more housings, which are stacked on top of each other via a first mechanical connection of the housing that mates with a second mechanical connection of an adjacent housing.

[0029] The mating may be achieved by aligning an inner diameter or side surface of a first mechanical connection defined by a first edge of a first component with an outer diameter or side surface of a second mechanical connection defined by a first edge of a third component, or vice versa.

[0030] The first component of the housing may be electrically insulating, or the housing may further comprise electrical insulation between the first component and a third component of an adjacent housing.

[0031] The first part of the housing may be in electrical contact with the third part of an adjacent housing. In each housing, the second edge of the second part may be electrically insulated from the first edge of the third part, and / or the first edge of the second part may be electrically insulated from the first edge of the first part.

[0032] The second part may be a container, and the first part may be a lid for the container. Alternatively, the first part may form half of the housing shell, and the second part may form the other half of the housing shell.

[0033] At least one of the plurality of parts may be rigid, and at least one of the other parts may be rigid or semi-rigid.

[0034] The present invention has a number of advantages. The present invention provides a housing that has a high level of safety and can be mass-produced rapidly at a competitive cost.

Brief Description of the Drawings

[0035] The present invention will be described below with reference to the accompanying drawings.

Figure 1a

Figure 1b

Figure 2a

Figure 2b

Figure 2c

Figure 2d

Figure 2e

Figure 2f

Figure 3a

Figure 3b

Figure 3c

Figure 3d

Figure 3e

Figure 4a

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Figure 4c

Figure 4d

Figure 5a

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Figure 5c

Figure 6a

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Figure 7a

Figure 7b

Figure 7c

[0036] The present invention relates to an electrochemical device, such as a battery or a fuel cell, comprising a stack of electrochemical devices forming a sheet including at least one first type of electrode sheet, at least one second type of electrode sheet, and at least one separator sheet between the two types of electrode sheets.

[0037] Aspects of the present disclosure present solutions for providing rigid or semi-rigid cell housings and casings or hulls with high safety levels that can be mass-produced at high speed at competitive costs.

[0038] The electrochemical device may comprise at least one housing, such a housing being formed using several components comprising a first component and a second component. Sheets of materials for forming an electrochemical device, such as a sheet of a first type of electrode, a sheet of a second type of electrode, and one or more separator sheets, can be arranged within the housing. Thereby, the stack may comprise at least one sheet of a first type of electrode, at least one sheet of a second type of electrode, and at least one separator sheet between the sheets of the two types of electrodes. The stack may further be a laminate in which the sheets form different layers of the laminate.

[0039] Next, a plurality of components are joined to each other to form the internal volume of the housing, and in this joining, encapsulation techniques used for tins and cans can be used, such as laser welding, conventional welding, or joining such as any type of hemming, crimping, or punch crimping.

[0040] At least one of the plurality of components may be rigid, and at least one of the other components may be semi-rigid.

[0041] The sheet may also be pre-soaked in the electrolyte. Alternatively, the electrolyte may be filled into the housing before or after the stack is disposed in the housing.

[0042] FIG. 1a shows a cross-sectional view of a first type of housing 10A formed as a box with a lid and including a first component 12A and a second component 14A. The second component 14A may be formed as a box or a cylinder, and the first component 12A may be formed as a rectangular or circular lid for the box or the cylinder. Thus, the second component 14A is a container, and the first component 12A is a lid of the container.

[0043] The second component 14A may more specifically have a bottom 14AB surrounded by at least one side wall 14AW, and the side wall 14AW may be oriented at a right angle to the bottom 14AB or be inclined at an angle. The first component 12A is further parallel to the bottom 14AB of the second component 14A. Thereby, a housing having an internal volume IVA22A is formed by the first component 12A and the second component 14A, and a stack can be arranged within this volume 22A. The first component 12A has a first edge 12AE, and the second component 14A may have a first edge 14AE. The first and second components 12A and 14A thus each have a first edge 12AE and 14AE respectively. The first edge 12AE of the first component 12A may be provided around the lid and extend beyond the wall 14AW of the second component 14A, while the first edge 14AE of the second component 14A may be angled away from the wall 14AW of the second component 14A, for example, at 90 degrees. The first edge 14AE of the second component 14A may be parallel to and aligned with the first edge 12AE of the first component 12A.

[0044] Furthermore, it can be seen that in this case, the housing comprises an upper part provided by the lid 12AL of the first component 12A and a bottom part formed by the bottom 14AB of the second component 14A in this case, and the upper part and the bottom part are separated by at least one side wall, and at least one side wall is formed by the wall 14AW of the second component 14A.

[0045] The first component 12A and the second component 14A may each further include a metal layer ML16 and an insulating layer IL18. The insulating layer 18 is provided inside the housing, i.e., faces inward toward the internal volume 22A, and the metal layer 16 is provided outside the component, i.e., faces away from the internal volume 22A. The first and second components 12A and 14A may thereby be essentially metallic, and the surfaces of the first and second components 12A and 14A that face inward toward the internal volume 22A of the housing are covered with or provided with the insulating material 18. Thereby, the surface of the lid 12AL of the first component 12A that faces the bottom of the second component 14A is covered with an insulating material, similar to the surface of the bottom 14AB of the second component 14A that faces the first component 12A. Also, the inner surface of the wall 14AW that faces inward toward the internal volume 22A of the housing is covered with the insulating material 18. Further, an insulating material can also be provided on the surfaces of the edges 12AE of the first component 12 that face the edges 14AE of the second component, and this insulating material can extend all the way to the rim or end of the corresponding edge, or partially to the rim or end, such as partway to the rim or end.

[0046] The metal layer 16 may be made of, for example, aluminum, and the electrically insulating inner layer 18 may be a polymer or ceramic (cold gas spray) fixed to the outer metal layer by, for example, adhesion or lamination. The rigidity of the first and second components may be finely adjusted by material selection and formation (e.g., embossing, etc.).

[0047] The first edge 12AE of the first component 12A may then be joined to the first edge 14AE of the second component 14A to form a first mechanical connection MCA20A between the first and second components, and the first mechanical connection MCA seals the housing. As described above, the joining may be performed using welding such as laser welding and resistance welding, crimping, punch crimping, or any type of hemming process.

[0048] Figure 1b shows a first version of a second type of housing 10B1 that includes a first component 12B and a second component 14B. The second component 14B may have the same implementation as the second component 14A of the first type of housing 10A. In this case, the second component 14B has the same shape as the second component 14A of the first type of housing, forms half of the shell, i.e., has a bottom 14BB, at least one side wall 14BW, and a first edge 14BE. Also, the first component 12B has the same shape as the second component and forms the second half of the shell. The first component 12B has a lid or top 12BL surrounded by at least one side wall 12BW. The side wall 12BW is oriented at a right angle to the lid or top 12BL. The lid or top 12BL of the first component 12B is parallel to and faces the bottom 14BB of the second component 14B. At least one wall 12BW of the first component 12B is aligned with at least one wall 14BW of the second component 14B. The edges 12BE and 14BE of the first component 12A and the second component 14A are joined to each other here in the same way as the first type of housing to form a first type of mechanical connection MCA20A.

[0049] Figure 2a schematically shows a first type of housing 10A. A stack ST24 that includes sheets forming a first electrode, a second electrode, and a separator is provided within the internal volume of the housing. The first and second components 12A and 14B are joined by a first mechanical connection 20A of the first type, which can be realized using any type of welding such as laser welding or conventional resistance welding or bonding.

[0050] Here, the stack has a first end with a bottom sheet that faces the bottom of the housing. The stack also has a second end with a top sheet that faces the top of the housing.

[0051] Figure 2b schematically shows a first variation of a second type of housing 10B1, in which a stack ST24 including a sheet forming a first electrode, a second electrode, and a separator is provided within the internal volume of the housing, and the housing is sealed again with a first mechanical connection 20A of the first type. The same joining techniques as for the first type of housing can be used.

[0052] Figure 2c schematically shows a second variation of a second type of housing 10B2 including a stack of sheets ST24 forming electrodes and a separator, in which case a first mechanical connection 20B of the second type is used. The joint may be further formed by crimping and punching the first edges of the first and second parts together, or by hemming. Thereby, the first mechanical connection 20B of the second type is obtained by folding the first edge of the first part 12B around the first edge of the second part 14B. The first mechanical connection 20B of the second type may be further hermetically sealed by providing a sealing agent or a sealing binder between the first edge of the first part 12B and the first edge of the second part 14B. It should be understood here that it is alternatively possible that the first edge of the second part 14B is folded around the first edge of the first part 12B. Alternatively, both edges can be rotated together by 180° (not shown in the schematic).

[0053] FIG. 2d shows a third variation of the second type of housing 10B3 and has a third type of first mechanical connection 20C similar to the first type 20A. Thus, there are first edges of the first and second components aligned with each other, but the edges are not folded over one another. However, in this case, a sealing groove is provided in the first edge of the second component 14B, and a sealing agent is placed in the groove and between the first edge of the first component 12B and the first edge of the second component 14B to hermetically seal the first mechanical connection 20C. This has the advantage of providing better control of where the sealing agent is applied in the first mechanical connection 20C. It should be understood that the sealing groove may be provided in the first edge of the first component. This sealing variation can be combined with any of the aforementioned joining mechanisms, for example, hemming.

[0054] Figure 2e shows a first version of a third type of housing 10C1b. In this type, there are a first component 12C and a second component 14C each having a first edge. However, there is also a third component 28 having a first edge. Further, the second component 14C also has a second edge. In this case, the first component 12C forms the lid or top of the housing, the third component 28 forms the bottom of the housing, and the second component 14C forms at least one wall disposed between the top and bottom of the housing. The first component 12C and the third component 28 are provided at both ends of the stack 24 in this case, and the second component 14C surrounds the stack. In this case, the first edge of the second component 14C is provided around one end of at least one wall and extends over the lid of the first component 12C, and the second edge of the second component 14C is provided around the other end of at least one wall and extends over the bottom of the third component 28. In this case, there is a second type of first mechanical connection 20B obtained by folding the first edge of the first component 12C around the first edge of the second component 14C, and a second mechanical connection MCB in which the first edge of the third component 28 is joined to the second edge of the second component. In this variation of the third type of housing 10C, the second mechanical connection is the same as the second type of the first mechanical connection and is the first type 30A obtained by folding the first edge of the third component 28 around the second edge of the second component.

[0055] As can be seen from the figure, it is similarly possible that the second mechanical connection MCB is of the second type 30B in which the second edge of the second component 14C is folded around the first edge of the third component 28. Similarly, instead of the first edge of the first component 12C being folded around the first edge of the second component 14C, it is also possible that the first edge of the second component 14C is folded around the first edge of the first component 12C. It is also possible to dispose a sealant at the first and second mechanical connections. Thus, the sealant may be used between the edges of at least one mechanical connection portion of the housing, or may advantageously be used between all mechanical connection portions of the housing.

[0056] The third type of housing has the advantage of being suitable for stacking the housings on top of each other.

[0057] As seen in Figure 2f, the shapes of the first and third parts and the cross-section of the second part can have a rectangular or circular form with various aspect ratios of combinations of x and y. The rectangular shape may or may not have a radius at the corners.

[0058] The first, second, and any third parts may further be made from a single aluminum or hybrid polymer-aluminum layer.

[0059] Figures 3a to 3e show different ways of applying pretension to the housing to enable compression of the housing.

[0060] Figure 3a schematically shows a first type of housing, with an external pretension element 32A disposed on the side wall of the second part. The pretension element 32A is flexible in the axial direction of the stack, i.e., in the direction between the top and bottom of the housing, thereby enabling the first part and the bottom of the second part to be pressed against each other.

[0061] Figure 3b shows a second type of external pretensioning element for a first version of a second type of housing. In this case, the side wall of the first part is connected to the first edge of the part via a first inclined portion 32B1, and the side wall of the second part is connected to the first edge of the part via a second inclined portion 32B2. The inclined portions 32B1 and 32B2 are inclined at about 0 to 45 degrees with respect to the corresponding walls and together form a second type of external pretensioning element. The inclined portions are flexible and allow the bottom and top of the first and second parts to be pressed against each other, and this pressing increases the angle with respect to the side walls. Furthermore, it is possible to increase the compressive force after the release of the external compressive force. This can be done, for example, when the inclined portions 32B1 and 32B2 are provided with a bonding material on their inner surfaces, i.e., their surfaces facing inward towards the internal volume. Pushing the angled parts towards each other can then bond them, thereby increasing the compressive force.

[0062] Therefore, it can be seen that there is at least one flexible compression element on the outside of at least one side wall.

[0063] Alternatively, each of the top and bottom may comprise a rigid or flexible compression element.

[0064] The housing may further comprise at least one pretensioning element provided at one end of the stack and facing the upper or lower sheet of the stack.

[0065] The at least one pretensioning element may further comprise an internal pretensioning element within an internal volume disposed between the stack and the upper or lower part of the housing. The at least one pretensioning element may additionally or alternatively comprise an external pretensioning element provided as the upper or lower part of the housing.

[0066] Figure 3c shows a first version of a second type of housing, in which such an internal pretensioning element in the form of a concave flexible pretensioning element 34 is provided at one end of the stack inside the housing. The pretensioning element 34 is more specifically provided within the internal volume of the housing, here between the upper part or lid 12BL of the rigid first part and the top of the stack. Further, the bottom 14BB of the second part is provided in this example as an external pretensioning element having a concave shape, and this bottom 14BB is provided at the opposite end of the stack, i.e., at the bottom of the stack. The concave sidewall or internal concave element can be an element in the shape of either a uniaxial concave or a double concave (90° offset). The left and right concave shapes may have their concave axes aligned or may be offset by 90°.

[0067] The concave pretensioning element has a focus. It should be understood that the pretensioning element is arranged between the stack 24 and this focus.

[0068] Pushing the upper part 12BL of the first part towards the lower part 14BB of the second part using the first edges of the first and second parts then results in the compression of the stack.

[0069] Figure 3d shows some additional elements added to the pretensioning element of the first version of the second type of housing of Figure 3c. For example, there may be a coupling element between the upper or bottom of the housing and the internal pretensioning element. In this case, there is a coupling element realized as an internal adhesive or joint gap filler 38 between the pretensioning element 34 and the upper part 12BL of the first part. Also, there may be a foam element on the external pretensioning element in a direction away from the stack. In this embodiment, there is a foam 40 outside the bottom 14BB of the second part. These elements 38 and 40 may be used to adjust the uniform pretensioning.

[0070] Here, it should be understood that only one of the pretensioning elements shown in FIGS. 3c and 3d, i.e., either the internal pretensioning element 34 or the external pretensioning element, can be used, and the only pretensioning element is provided at either of the two ends of the stack. Further, when two pretensioning elements are used, they may both be of the same type, either internal or external, or may even be part of the cell housing itself.

[0071] FIG. 3e schematically shows a first version of a second type of housing, with a corrugated depression provided in the upper part 12BL of the first part and the bottom part 14BB of the second part. Thus, it can be seen that the upper part 12BL of the first part and / or the bottom part 14BB of the second part is corrugated.

[0072] It is possible to use a waveform conforming element within the internal volume aligned with the corresponding bottom or upper waveform, and this waveform conforming element flattens the grooves on the bottom facing the stack and / or the inner surface of the lid. In this case, the waveform conforming element 44 is provided via an adhesive or a gap filler-like bond between two layers, similar to FIG. 3d. Here, such an adhesive or gap filler 44 exists between the bottom of the first part and the adjacent bottom sheet of the bottom of the stack. By providing the waveform conforming element, it is ensured that the waveform does not change the shape of the sheet, such as creating a depression, during compression.

[0073] Here, it should be understood that it is further possible to combine the pretensioning elements shown in FIGS. 3c and 3d with the corrugated depressions. Thus, there may be one or two concave pretensioning elements combined with the corrugated top and / or bottom. Thus, the concave elements may be combined with the local waveform to improve rigidity and compression.

[0074] Instead of, or in addition to, using different types of pretension elements, the height of the housing can be made smaller than the original stack height in the axial direction of the stack, where the original stack height is understood to be the stack height before the stack is placed within the internal volume. The stack is compressed by pressing the first part axially towards the second part and / or the third part. In this case, the compression operation is initiated before the parts are joined to each other, and the joining takes place when the three parts described above are pressed against each other. The upper and lower parts of the housing thereby compress the stack. In that case, no additional compression adjustment elements are required, but they can optionally be integrated.

[0075] The stack may thus be compressed by the pressure applied through the upper and lower parts of the housing, or the first and another opposing side walls. The stack is compressed by pressing the upper or first side wall axially towards the lower or other side wall. Of course, additionally or alternatively, the lower or other side wall can be pressed towards the upper or first side wall.

[0076] Furthermore, there may be a first electrical connection to the first type of electrode and a second electrical connection to the second type of electrode.

[0077] Figures 4a - d disclose different ways of providing such electrical connections for different types of electrodes within different types of housings.

[0078] In Figures 4a - d, all electrodes of the first type are connected to a first connection strip 46 provided on one side of the stack, all electrodes of the second type are connected to a second connection strip 48 provided on the opposite side of the stack, the first connection strip 46 is connected to a first conductor exiting the housing, and the second connection strip 46 is connected to a second conductor exiting the housing. The connection strips may be realized as separate tab parts, or may be formed, in part or in whole, by uncoated electrode foil sections.

[0079] Figure 4a shows one implementation in the housing 10A of the first type, where the first connection strip 46 is provided along the wall of the second component on one side of the stack, and the first conductor 50A exits the housing through the first mechanical connection on this side of the stack. The second connection strip 48 is provided along the wall of the second component on the opposite side of the stack, and the second conductor 52A exits the housing through the first mechanical connection on the same side of the stack.

[0080] The first and second electrical connections are thereby provided through the first mechanical connection. More specifically, the first electrical connection is provided between the first edge of the first component and the first edge of the second component on the side wall of the second component located on one side of the stack, and the second electrical connection is provided between the first edge of the first component and the first edge of the second component on the other opposite side wall of the second component located on the opposite side of the stack.

[0081] Figure 4b shows an implementation in the first variation of the housing 10B1 of the second type, where the first connection strip 46 is provided along the walls of the first and second components on one side of the stack, and the first conductor 50B exits the housing through the first mechanical connection on this side of the stack. The second connection strip 48 is provided along the walls of the first and second components on the opposite side of the stack, and the second conductor 52B exits the housing through the first mechanical connection on the same side of the stack. It can be seen that the side of the stack along which the first connection strip 46 is provided is the same as the side along which the second connection strip 48 is provided in the housing of the first type in Figure 4a.

[0082] Here, it should be mentioned that it is possible to provide two tabs of insulating material at the mechanical connection. The first and second conductors exit the internal volume through these two tabs. If an insulating layer is provided at the first edges of the first and second components, this insulating layer can provide additional insulation. The use of the tabs will be described in more detail in connection with Figures 4c and 4d.

[0083] Furthermore, one of the electrical connections may be provided through a side wall of the housing, and the other electrical connection may be provided through the opposite side wall of the housing.

[0084] Figure 4c shows a first implementation in a first variation of a third type of housing 10C1 that illustrates this. In this case, the first conductor 50C exits the housing through a first portion of the wall of the second component, and the second conductor 52C exits the housing through a second portion of the wall of the second component, where a part may be the side surface of the wall having a rectangular cross-section. In this case, the first conductor 50C may be surrounded by an insulating material 56, and the conductor and the insulating material may be provided in the form of tabs penetrating the wall. The second conductor 52C may be surrounded by an insulating material 54, and the conductor and the insulating material may be provided in the form of tabs penetrating the wall. It can be seen that the side of the stack along which the first connection strip 46 is provided is the same as the side along which the first connection strip 46 is provided in the first variation of the second type of housing in Figure 4b. It can be seen that the walls through which the first and second conductors exit the housing are the same as those in Figure 4b.

[0085] Alternatively, one electrical connection may be provided through the top of the housing, and the other may be provided through the bottom of the housing.

[0086] Figure 4d shows a second implementation of a first version of a third type of housing 10C1 that illustrates this. In this case, the first conductor 50D exits the housing through the first component, while the second conductor 52D exits the housing through the third component. Both conductors are provided within tabs, and insulators 54 and 56 surround the conductors 50D, 52D, and these tabs penetrate the corresponding components.

[0087] As yet another alternative, both electrical connections may be provided through the same surface. Thus, they may be provided through the top, the bottom, or the same side wall.

[0088] FIG. 5a shows a side view of the second component 14C by a third type of housing before being folded into a box shape, as shown from above. In this case, there are a first tab 58 for a first electrical connection through the first wall and a second tab 60 for a second electrical connection through the wall. The first tab 58 includes a first conductor 52C surrounded by an insulator 54, and the second tab 60 includes a second conductor 50C surrounded by an insulator 56. Also, there is a vent element 62 in the form of a vent disk provided on the second and fourth walls of the second component 14C to release the pressure inside the housing, for example, in case of thermal runaway.

[0089] The vent element is shown as being provided on the second and fourth walls of the second component, but it should be understood that the vent element may alternatively or additionally be arranged on the first and / or third walls. There may be only one vent element in the second component. The vent element may be provided on the first and / or third components. Therefore, it should be understood that the vent element can be provided on the top, bottom, or at least one wall.

[0090] FIG. 5b shows, from left to right, a top view of an empty second component 14C by a third type of a first type of housing having first and second tabs composed of a first conductor 50C surrounded by an insulator 56 and a second conductor 52C surrounded by an insulator 54, passing through the first and third walls. The second component can consist of a bent and welded / bonded metal sheet or a direct extrusion polymer, a stack 46 of sheets having a first connection strip 46 provided on the first side of the stack and a second connection strip 48 provided on the second side of the stack, and a stack 24 having connection strips 46 and 48 arranged inside the housing in contact with the first and second conductors 56 and 54 of the two tabs.

[0091] Figure 5c schematically shows side views of stack 24 connected to first and second conductors 50C and 52C provided via a second component 14C of a first version of a third type of housing, via first and second connection strips, from left to right; a side view of stack 24 connected to first and second conductors 50C and 52C provided via a second component 14C of a first version of a third type of housing, via first and second connection strips, when the second component 14C is coupled to first and third components 12C and 28; and a side view of stack 24 connected to first and second conductors 50C and 52C provided via a second component 14C of a first version of a third type of housing, via first and second connection strips, when first and third walls are corrugated for pretensioning purposes and the first and second components are pressed against each other.

[0092] As can be seen in FIGS. 5a - 5c, at least one electrical connection may comprise a tab extending from within the housing to the outside of the housing, the tab comprising a conductor surrounded by an insulator.

[0093] FIGS. 6a and 6b show alternatives in providing electrical connections to electrode sheets in fourth and fifth types of cell housings 1D and 10E.

[0094] The fourth type of housing 10D includes a first component with a lid or top 12DL joined by a wall 12DW, a bottom 14DW, and a bottom 12DB, and a second component 14D formed through the first, second, and third walls 14DW1, 14DW2, and 14DW3. The first wall 14DW1 and the third wall 14DW3 of the second component are parallel to each other, and the second wall 14DW2 of the second component is perpendicular to both and joined to them. The aforementioned tabs are also provided on the first wall 14DW1 and the third wall 14DW3. During cell assembly, the stack 24 is first connected to the tabs on the first and second walls 14DW1 and 14DW3, and then the second component is slid between the top 12DL and the bottom 12DB of the first component until the first and second walls 14DW1 and 14DW3 of the second component abut the wall 12DW of the first component. As a result, the first, second, and third walls 14DW1, 14DW2, and 14DW3 of the second component, together with the wall 12DW of the first component, form the side walls of the housing between the lid 12DL and the bottom 12DB. Then, the two components may be joined to each other using any of the aforementioned techniques such as adhesion, welding, hemming, crimping, etc.

[0095] In the fifth type of housing 10E, the bottom 14EB is instead a part of the second component that is perpendicular to and joined to the first, second, and third walls 14EW1, 14EW2, and 14EW3. Here too, the aforementioned tabs are provided on the first and third walls 14EW1 and 14EW3. In this case, the second component can be slid under or directly under the top 12EL of the first component until the first wall 14EW1 and the third wall 14EW3 of the second component abut the wall 12EW of the first component.

[0096] It should be understood here that this structure is similarly applicable to a stack joined to the tabs at the top and bottom of the housing. In this case, the first and second components of the fourth and fifth types of housing can be considered to be, instead, the second and first components of the sixth and seventh types of housing, respectively.

[0097] It is possible to stack different housings on top of each other. The electrochemical device may thus comprise two or more housings. Further, if the housings are of a third type, they may be stacked on top of each other via a first mechanical connection of the housing that mates with a second mechanical connection of an adjacent housing.

[0098] Figures 7a - c show how this can be done for a third type of housing.

[0099] Figure 7a shows a stack of housings 10C1A, 10C1B, and 10C1C according to a first version of the third type. As can be seen from the figure, it is here possible for the first mechanical connection to have an inner diameter or side surface defined by a first edge of a first part that is aligned with an outer diameter or side surface of a second mechanical connection defined by a first edge of a third part. More specifically, a part of the first edge of the first part that is placed on the inner surface of the first edge of the second part can be adapted to and placed on a part of the first edge of the third part that is placed on the outer surface of the second edge of the second part.

[0100] Furthermore, it is possible for the first part of each housing to be electrically insulating, or for the housing to further comprise electrical insulation between its first part and the third part of an adjacent housing with which it mates.

[0101] Figure 7b shows a stack of housings 10C2A, 10C2B, and 10C2C according to a second version of the third type, where this is illustrated. As can be seen in Figure 7b, it is also possible to electrically insulate the first part 12C, or to place an electrical insulator 64 between the first part 12C of the housing and the third part of a subsequent housing in the housing stack, and the insulator must also be placed around the first mechanical connection. The insulator 64 may be provided as an additional layer provided on the outside of the first part 12C of each housing 10C2. Alternatively, it is possible for the third part to receive this treatment instead.

[0102] The first part of the housing is in electrical contact with the third part of an adjacent mating housing, and in each housing, the second edge of the second part is electrically insulated from the first edge of the third part, and / or it is further possible that the first edge of the second part is electrically insulated from the first edge of the first part.

[0103] Figure 7c shows a stack of housings 10C3A, 10C3B, and 10C3C according to a third version of a third type that illustrates this situation. As seen in Figure 7C, when the first and second electrical connections are provided via the first and third parts 12C and 28, it is possible to electrically interconnect the stacked housings. In this case, the first part 12C and the third part 28 are used to electrically connect one housing 10C3B within the housing stack to an adjacent housing 10C3A. To avoid short circuits, the second mechanical connection, in particular, the second edge of the second part used for the second mechanical connection of said one housing 10C3B, may be insulated from the first edge of the third part within the same housing, as well as from the first edge of the first part of the adjacent housing 10C3A against which the second mechanical connection rests or abuts 68. Here, alternatively, it should be understood that the first mechanical connection, more specifically, the first edge of the second part, can similarly be insulated from the first edge of the first part, or the first edge of the third part against which the first part abuts.

[0104] Thus, there are combinations of cells into modules, strings, and packs by mechanical coupling only (Figure 7a), mechanical insulation and direct mechanical coupling (Figure 7b), and electrical coupling (Figure 7c). The crimped or bonded cell areas can also be used to fix onto the mechanical structure of the module or pack.

[0105] Aspects of the present disclosure provide solutions for providing rigid cell enclosures and hulls with competitive costs, high speed, and high safety levels in mass production. Additionally, many cell chemistries require compression of the cells when assembled into modules or packs. This is an inaccurate method, leading to complex and failure-prone systems, and due to inaccurate compression conditions, resulting in low or unpredictable aging behavior of the entire module for a single cell within the module.

[0106] The gist of the present disclosure is as follows: · Cost-effective half-shell formation with multiple options for later closure lid fixation. · Embodiments where the cell stack is packed within a hybrid hull consisting of a mechanically rigid part and an electrical insulation layer. · A combination of a rigid element and a predefined flexible element for adjusting cell compression. These embodiments with pre-tensioned hulls or housing parts enable electrode stack compression without the need to compress at the module or pack level (tension-free assembly at the module and pack levels). · Use of existing mass production processes from the food packaging industry adapted to given conditions of cell encapsulation. · Preparation of hull or housing shapes for easy and cost-effective stacking of cells into modules and packs.

[0107] From the above description, it is clear that the present invention can be modified in numerous ways. The schematic diagrams shown represent only exemplary embodiments, and a given list of embodiments should be considered non-limiting. Thus, it should be understood that the present invention is limited only by the following claims.

Claims

1. An electrochemical device comprising at least one housing (10A; 10B1; 10B2; 10B3; 10C1; 10C2; 10C3; 10D; 10E) for a stack (24) of sheets of an electrochemical device forming material comprising at least one sheet of a first type of electrode, at least one sheet of a second type of electrode, and at least one separator sheet between the sheets of the first and second types of electrodes, wherein the housing comprises a plurality of parts including a first part (12A; 12B; 12C) and a second part (14A; 14B; 14C), and the plurality of parts are joined to each other using welding, hemming, crimping, or punch crimping to form an internal volume (22A; 22B) for accommodating the stack. The electrochemical device.

2. The first and second parts each have a first edge (12AE, 12BE; 14AE, 14BE), and the first edge (12AE; 12BE) of the first part (12A; 12B) is joined to the first edge (14AE; 14BE) of the second part (14A; 14B) to form a first mechanical connection (20A; 20B; 20C). The electrochemical device according to claim 1.

3. The electrochemical device according to claim 2, wherein the first edge of the first part is folded around the first edge of the second part, or vice versa.

4. The plurality of parts further comprises a third part (28) including a first edge, the second part comprises a second edge, and the first edge of the third part is joined to the second edge of the second part to form a second mechanical connection (30A; 30B). The electrochemical device according to claim 2 or 3.

5. The electrochemical device according to claim 4, wherein the first edge of the third part is folded around the second edge of the second part, or vice versa.

6. The housing of the electrochemical device according to any one of claims 1 to 5 comprises an upper part (12AL; 12BL; 12DL; 12EL) and a bottom part (14AB; 14BB; 28; 12DB; 14EB) separated by at least one side wall (14AW; 12BW, 14BW; 12DW, 14DW1, 14DW2, 14DW3; 12EW, 14EW1, 14EW2, 14EW3).

7. The electrochemical device according to claim 6, further comprising the stack (24) within the internal volume, the stack being compressed by a pressure applied through the upper and bottom portions or the first side wall and another opposing side wall of the housing.

8. The upper portion (12AL; 12BL), the bottom portion (14AB; 14BB), and the at least one side wall (14AW; 12BW, 14BW) are made of a metallic material (16), and the surface of the metallic material (16) facing the internal volume is coated with an electrically insulating material (18) or is a polymer, according to the electrochemical device of claim 6 or 7.

9. The electrochemical device according to any one of claims 6 to 8, further comprising at least one flexible compression element (32A; 32B1, 32B2) on the outside of the at least one side wall or on the outside of each of the upper and bottom portions.

10. The electrochemical device according to any one of claims 6 to 9, wherein the bottom portion (14BB) and / or the upper portion (12BL) is corrugated.

11. The electrochemical device according to any one of claims 6 to 10, further comprising at least one pretensioning element (34; 14BB), each pretensioning element being provided at one end of the stack (24) and facing the upper sheet or the lower sheet of the stack (24).

12. The electrochemical device according to claim 11, wherein the at least one pretensioning element includes an internal pretensioning element (34) within the internal volume (22B) disposed between the stack (24) and the upper portion (12BL) or the bottom portion (14BB) of the housing.

13. The electrochemical device according to claim 11 or 12, wherein the at least one pretensioning element comprises an external pretensioning element (14BB) provided as the upper or lower portion of the housing.

14. The electrochemical device according to any one of claims 11 to 13, wherein the at least one pretensioning element (34, 14BB) is concave with a focus, and the pretensioning element (34, 14BB) is disposed between the stack (24) and the focus.

15. The electrochemical device according to any one of claims 6 to 14, further comprising at least one venting element (62) in the upper portion, the bottom portion, or the at least one wall (14C).

16. The electrochemical device according to any one of claims 1 to 15, further comprising a first electrical connection to the first type of electrode and a second electrical connection to the second type of electrode.

17. The electrochemical device according to claim 16, which depends on claim 2, wherein the first and second electrical connections are provided via the first mechanical connection (20A).

18. The electrochemical device according to claim 16, which depends on claim 6, wherein one electrical connection is provided via a side wall of the housing and the other electrical connection is provided via a side wall on the opposite side of the housing.

19. The electrochemical device according to claim 16, which depends on claim 6, wherein one electrical connection is provided via an upper portion of the housing and the other electrical connection is provided via a bottom portion of the housing.

20. The electrochemical device according to any one of claims 17 to 19, wherein at least one electrical connection comprises tabs (58, 60) extending from inside the housing to the outside of the housing, and the tabs comprise conductors (52C, 50C) surrounded by insulators (54, 56).

21. The electrochemical device according to any one of claims 1 to 20, which depends on claim 4, wherein the electrochemical device comprises two or more housings, and the housings (10C1A, 10C1B, 10C1C; 10C2A, 10C2B, 10C2C; 10C3A, 10C3B, 10C3C) are stacked on top of each other via the first mechanical connection (20C) of a housing (10C1A; 10C2A; 10C3A) that mates with a second mechanical connection (30A) of an adjacent housing (10C1B; 10C2B; 10C3B).

22. The electrochemical device according to claim 21, wherein the mating is achieved via an inner diameter or side surface that is aligned with an outer diameter or side surface of the second mechanical connection defined by the first edge of the third component, and is via the first mechanical connection having an inner diameter or side surface defined by the first edge of the first component, or vice versa.

23. The electrochemical device according to claim 21 or 22, wherein the first component (12C) of the housing (10C2A) is electrically insulating or further comprises an electrical insulator (64) between the first component (12C) of the housing (10C2A) and the third component (28) of the adjacent housing (10C2B).

24. The first component (12C) of the housing (10C3A) is in electrical contact with the third component (28) of the adjacent housing (10C3B), and in each housing, the second edge of the second component is electrically insulated (68) from the first edge of the third component, and / or the first edge of the second component is electrically insulated from the first edge of the first component, the electrochemical device according to claim 21 or 22.

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