Electrochemical device equipped with safety device for pouch cells

Abstract

The electrochemical device comprises a device having at least one pouch cell (14A, 14B, 14C, 14D, 14E, 14F) and a safety device, wherein the safety device comprises a holding structure (13) and at least one pouch perforating element (24A, 24B, 24C, 24D, 24E, 24F) held by the holding structure adjacent to the corresponding pouch cell, with its perforating end facing the corresponding pouch cell, and each flexible pouch cell being attached to the holding structure and expandable in at least one direction, where one of the directions is toward the corresponding perforating element (24A) such that the perforating element perforates pouch cell (14A) at its perforating end.

Description

Technical Field

[0001] The present invention relates to an electrochemical device comprising at least one pouch cell and a safety device for the pouch cell.

Background Art

[0002] Lithium-ion batteries, which have been dominant as power sources for household appliances, are expanding into transportation fields such as electric vehicles (EVs), as well as stationary energy storage fields such as grid support and uninterruptible power supply (UPS) devices for data centers.

[0003] In battery development, several technological trends can be observed. Some of those trends are as follows: 1. Batteries using cell chemistries that do not have defective or problematic elements such as cobalt, 2. Cells having either large cell sizes or high-energy chemistries, 3. High-power batteries capable of high-speed charging and discharging.

[0004] Typically, those high-energy and high-power performances are achieved at the expense of an increased safety risk.

[0005] One such safety risk that can occur is thermal runaway.

[0006] Thermal runaway is defined as an incident where a cell increases its temperature through self-heating in an uncontrollable manner, which causes gas generation within the cell. Thermal runaway can be induced by different abusive conditions. Certain abusive conditions such as overcharging and overheating can exacerbate gas generation or even lead to a major disaster. In overcharging, gas generation mainly occurs through the electrochemical oxidation of the electrolyte solvent on the cathode, and Li ions from the electrolyte are reduced to metallic Li on the anode. In overheating, gas generation occurs not only through redox decomposition but also through the chemical decomposition of the electrolyte solvent on both the anode and the cathode, in addition to the vapor expansion of the volatile electrolyte solvent. CO, H2, C + H x H yThe generated gas containing the seeds is flammable.

[0007] To address safety concerns, several fail-safe designs, such as safety vents and thermal fuses, are implemented in commercially available cells.

[0008] Pouch cells are attractive for use in batteries due to their simple design and the low amount of additional parts and mass they require.

[0009] However, a simple pouch design shifts some features to a higher level of integration, such as module integration or pack integration. For example, commercially available pouch-type cells lack a discharge design. Gases generated by heavy use or severe degradation accumulate inside the pouch bag, resulting in balloon-like inflated cells. Inflated cells, in turn, lead to deformation of the battery module.

[0010] New safety features are needed in pouch cells.

[0011] One solution described in KR101452028 uses a discharge assembly with a needle-like structure positioned between two pouch cells. When one of the pouch cells expands, it is pressed against the discharge assembly, which then causes the needle-like structure to protrude, creating a hole in the pouch cell.

[0012] However, there is still room for improvement in this area, particularly regarding the control of drilling operations. [Overview of the project]

[0013] One object of the present invention is to provide an improved electrochemical device comprising a pouch cell, the improvement being obtained particularly with respect to the control of the perforation operation performed when the pouch cell is exposed to thermal runaway.

[0014] This objective is achieved through an electrochemical device comprising at least one pouch cell and a safety device, wherein the safety device comprises a retaining structure and at least one pouch perforating element held by the retaining structure adjacent to a corresponding pouch cell, the perforating end of which faces the corresponding pouch cell, each pouch cell being attached to the retaining structure and expandable in at least one direction, where one of the directions is toward the corresponding perforating element such that the perforating element perforates the pouch cell at its perforating end.

[0015] The retaining structure can be a retaining structure that holds the perforating element of the safety device.

[0016] According to one variant of the electrochemical device, the holding structure comprises at least one element that applies pressure to at least one pouch cell in order to restrict the possible directions of expansion.

[0017] The pouch cell can also be enclosed within a hemming structure. In this case, the retaining structure may surround the pouch cell and may further comprise first and second pieces, each having a first edge, where the first edge of the first piece folds around the first edge of the second piece, or vice versa, to form a first mechanical connection. In this case, a perforating element may be positioned between the pouch cell and the retaining structure, adjacent to the first mechanical connection.

[0018] The first and second pieces may be made of metal. Alternatively, they may be made of ceramic or polymer material.

[0019] When a hemming structure is used, the pouch cell may be further surrounded by an insulating or heat-sealing material, which may have cavities adjacent to the perforated elements, within which the pouch cell can expand.

[0020] The electrochemical device may further comprise a first fluid channel for the transfer of fluid to or from the pouch cell and, according to some, also to or from the perforated element.

[0021] The transfer of fluid from the pouch cell may include the discharge of gas generated in the pouch cell due to thermal runaway. The transfer of fluid to the pouch cell may include the transfer of a coolant fluid and / or a flame retardant to the pouch cell.

[0022] The first fluid channel may additionally be part of the retaining structure.

[0023] Additionally, a second fluid channel may be provided in the perforated element and may extend between a first opening provided at the perforated end and a second opening provided at the other end of the perforated element, where the second fluid channel enables fluid to flow between the exterior and interior of the pouch cell.

[0024] The second opening of the perforated element may also be an opening in the wall of the first fluid channel.

[0025] The perforated element may additionally or alternatively be attached to the retaining structure via a first elastic element.

[0026] The pouch cell may further be attached to the perforated element or the retaining structure via a second elastic element. ]>

[0027] The electrochemical device may further comprise a heat-sensitive film between the pouch cell and the retaining structure. [[ID=]29]

[0028] <H When the retaining structure comprises the first fluid channel, additionally, a first elastic element may be disposed between the pouch cell and the inner wall of the first fluid channel furthest from the pouch cell. In this case, the expansion of the pouch cell may move the perforated element from a first position to a second position, where the second opening is separated from the first fluid channel in the first position and opens into the first fluid channel in the second position.

[0029] Here, the expansion of the pouch cell makes it possible to move the perforating element in the direction of expansion such that the second opening enters the first fluid channel. The perforating element is, in this case, arranged in a channel connection that leads into the first fluid channel and can be moved therein.

[0030] The heat-sensitive film can be arranged in the second fluid channel of the perforating element so as to rupture the heat-sensitive film when the pouch cell expands along the direction of expansion.

[0031] The holding structure can be a tape fastened to the pouch cell.

[0032] The heat-sensitive film can be provided between the perforating end of the perforating element and the pouch cell so as to be softened by the heat emitted from the pouch cell, release the perforating element, and move towards the pouch cell.

[0033] In the electrochemical device, there can be more than one pouch cell. In this case, the holding structure can include a perforating element for each pouch cell, and the first fluid channel can pass by each perforating element.

[0034] The pouch cell can additionally be provided in at least one stack, where each layer of the stack includes at least one pouch cell. In this case, the holding structure can include several support plates, one for each of two layers of the stack, where the edge of the support plate is folded over the first edge of the pouch cell of the corresponding first stack layer or vice versa, and the first fluid channel is provided between these overlapping edges.

[0035] In this case, additionally, it is also possible for another edge of the support plate to be folded over the second edge of the pouch cell of the corresponding second stack layer or vice versa.

[0036] The present invention will be described below with reference to the accompanying drawings.

Brief Description of the Drawings

[0037] [Figure 1] A perspective view of a first embodiment of an electrochemical device having a housing in which several pouch cells are stacked on top of each other is shown. [Figure 2] A side view of a first embodiment of an electrochemical device comprising a retaining structure having a first fluid channel and several perforating elements of a first type having a second fluid channel is shown. [Figure 3] A side view of a first embodiment of an electrochemical device is shown, in which the first pouch cell experiences thermal runaway and is perforated by a corresponding perforating element. [Figure 4] A side view of the first type of perforating element is shown. [Figure 5] A perspective view of a second embodiment of an electrochemical device is shown, which comprises a housing in which pouch cells are stacked in several stack layers separated by support plates. [Figure 6] The image shows a top view of two pouch cells in the first layer of a stack, which is mounted on a support plate, with the first edge of the support plate folded over the first edge of the pouch cells in the first layer. [Figure 7] The image shows a side view of the first and second layers of the stack inside the housing, in which the first edge of the first support plate is folded over the first edge of the pouch cell of the first layer, the second edge of the first support plate is folded over the second edge of the pouch cell of the second layer, and a second type of perforating element is provided on the folded edge. [Figure 8] Figure 7 shows the same side view, where the pouch cell in the second layer experiences thermal runaway and is perforated by the corresponding perforating element. [Figure 9] A top view of a third embodiment of an electrochemical device comprising a pouch cell without a perforating element is shown, where the corners of the electrochemical device are shown in more detail. [Figure 10A] This shows a cross-sectional view of the corner of an electrochemical device containing a third type of perforating element. [Figure 10B] A top view of the corner section having a perforation element is shown. [Figure 11] A side view of a modified form of a second embodiment of the electrochemical device is shown, in which the first support plate covers the entire top of the first layer and the entire bottom of the second layer of the pouch cell. [Figure 12] A perspective view of a pouch cell having a cooling plate with cooling channels is shown. [Figure 13] A side view of a pouch cell with a cooling channel is shown. [Figure 14] This shows a side view of a pouch cell with a cooling channel when the pouch cell experiences thermal runaway and is perforated by a corresponding perforating element, which is a first type of deformation. [Figure 15] A side view of the fourth type of drilling element is shown. [Figure 16] A side view of a fourth type of perforating element used with a pouch cell and a first fluid channel is shown. [Figure 17] The image shows a side view of the fourth type of perforating element, the pouch cell, and the first fluid channel when the pouch cell experiences thermal runaway and is perforated by the perforating element. [Figure 18] A perspective view of another embodiment of the electrochemical device is shown, in which the perforation element retention structure is provided as an discharge tape attached to the pouch cell. [Figure 19] This shows a top view of a pouch cell with an discharge tape. [Figure 20] This shows a top view of a modified pouch cell having an ejection tape equipped with a thermal film. [Figure 21] This is a top view of a deformed pouch cell having a discharge tape equipped with a heat-sensitive film, when the pouch cell experiences thermal runaway and is perforated by a perforating element. [Figure 22] A perspective view of a housing with two pouch cells, through which the cooling fluid is supplied via a cooling fluid inlet / outlet, is shown. [Figure 23] A perspective view of a modified housing configuration with two pouch cells is shown. [Figure 24] A perspective view of another variant of the housing, which has four pouch cells, is shown. [Figure 25] A perspective view of yet another variation of the housing, which has eight pouch cells, is shown. [Figure 26] A perspective view of an embodiment of an electrochemical device comprising several housings is shown, where the inlets / outlets of the housings are interconnected with cooling fluid tubes. [Modes for carrying out the invention]

[0038] The present invention relates to an electrochemical device such as a battery or supercapacitor, comprising at least one pouch cell and a holding structure for holding at least one perforation element.

[0039] Aspects of this disclosure present solutions for addressing thermal runaway in electrochemical devices comprising pouch cells, which may be electrochemical cells such as batteries or supercapacitors.

[0040] A pouch cell is a cell in which the pouch or bag is flexible. The pouch may comprise a metal layer and two insulating layers, where the metal layer is sandwiched between the two insulating layers.

[0041] The metal layer may be made of, for example, aluminum, and the electrical insulating layer may be a polymer or ceramic (cold gas spray) fixed to the metal layer by bonding or lamination.

[0042] During the operation of a pouch cell, thermal runaway can occur within the cell. This condition is serious and, if left untreated, can lead to the explosion of the pouch cell.

[0043] Aspects of this disclosure relate to addressing thermal runaway in an electrochemical device comprising at least one pouch cell. Thermal runaway is addressed by using a safety device comprising a retaining structure to which at least one pouch cell is connected, the retaining structure comprising a perforating element for each such pouch cell. How such an electrochemical device may be realized is described in more detail below.

[0044] Herein, a first embodiment of the electrochemical device is described with reference to Figures 1-4, where Figure 1 shows a perspective view of an electrochemical device comprising a housing in which several pouch cells are stacked on top of each other; Figure 2 shows a side view of an electrochemical device comprising a safety device comprising a holding structure having a first fluid channel and several perforating elements of a first type, each having a second fluid channel; Figure 3 shows a side view of an electrochemical device in which the first pouch cells experience heat and are perforated by the corresponding first perforating elements; and Figure 4 schematically shows the first type of perforating element. The holding structure is a structure for holding the perforating elements of the safety device.

[0045] One purpose of a fluid channel is to be used as a vent channel that allows gases generated inside the pouch cell to escape. As we will see later, fluid channels can also be used to inject fire extinguishing liquid / agent and supply cooling fluid into the pouch cell.

[0046] Each pouch cell has a first electrical terminal 16A and a second electrical terminal 18A, which can be either an anode or a cathode terminal. In the drawing, the first and second electrical terminals 16A and 18A of the first pouch cell 14A are shown, but only the first electrical terminals 16B to 16F of the other pouch cells 14B to 14F are shown.

[0047] Figures 1-3 outline a first embodiment of an electrochemical device 10A comprising a housing 12 enclosing several pouch cells 14A-14F and several perforation elements 24A-24F. Examples include the first pouch cell 14A, the second pouch cell 14B, the third pouch cell 14C, the fourth pouch cell 14D, the fifth pouch cell 14E, and the sixth pouch cell 14F. The pouch cells are arranged in a stack, where the pressure plates of the holding structure 13, together with several insulating plates 22A, 22B, 22C, 22D, 22E, and 22F, apply pressure in at least one direction, in this case the vertical direction, within the pressurized area PA. The pressure plates here are elements that apply pressure to the pouch cells to limit the possible directions of expansion of the pouch cells. Here, there is a first pressure plate on the top side of the first pouch cell 14A, a first insulation plate 22A between the first pouch cell 14A and the second pouch cell 14B, a second insulation plate 22B between the second pouch cell 14B and the third pouch cell 14C, a third insulation plate 22C between the third pouch cell 14C and the fourth pouch cell 14D, a fourth insulation plate 22D between the fourth pouch cell 14D and the fifth pouch cell 14E, a fifth insulation plate 22E between the fifth pouch cell 14E and the sixth pouch cell 14F, and a sixth insulation plate on the bottom side of the pouch cell 14F.

[0048] The retaining structure 13 is also, in this case, a modular frame for the pouch cell.

[0049] As shown in Figures 1-3, the holding structure 13 also includes a first fluid channel 20, which is connected to a pressure plate. The first fluid channel 20 is provided for the transfer of fluid to and from the pouch cells 14A, 14B, 14C, 14D, 14E, 14F and the perforating elements 24A, 24B, 24C, 24D, 24E, 24F. In this example, the first fluid channel 20 is a vertically oriented discharge channel for discharging the pouch cells 14A, 14B, 14C, 14D, 14E, 14F, while the pressure plate is horizontally oriented. A portion of the first pouch cell 14A facing the first fluid channel 20 is not in contact with the pressure plate, and thereby the pressure applied to this portion of the first pouch cell 14A and the corresponding portions of the pouch cells 14B-14H below it is lower than the pressure in the pressurized area PA. This lower pressure area is therefore called the Low Pressure Area (LPA).

[0050] In this embodiment, there are more than one pouch cell in the electrochemical device. In this case, the holding structure includes a perforation element for each pouch cell. It can also be seen that a first fluid channel passes beside each perforation element. Furthermore, the pouch cells are provided in additionally at least one stack, in this case one stack comprising several layers, where each layer comprises one pouch cell.

[0051] Therefore, the holding structure 13 is a holding structure that holds several perforating elements, one for each pouch cell. Thus, there is a first perforating element 24A for the first pouch cell 14A, a second perforating element 24B for the second pouch cell 14B, a third perforating element 24C for the third pouch cell 14C, a fourth perforating element 24D for the fourth pouch cell 14D, a fifth perforating element 24E for the fifth pouch cell 14E, and a sixth perforating element 24F for the sixth pouch cell 14F.

[0052] In this first embodiment of the electrochemical device 10A, the perforating element used is of the first type.

[0053] An implementation of the first perforating element 24A according to this first type is schematically shown in Figure 4. The perforating element 24A has a first perforating end PE and a second bottom end BE. The perforating element 24A also has a second fluid channel 30 extending between a first opening 26 provided at the perforating end PE and a second opening 28 provided at the other end of the perforating element, which in this case is the bottom end BE. The perforating element can be formed as a hollow frustocone. It can also be considered as a cylinder having a uniform inner diameter and an outer diameter that increases from the perforating end PE towards the base end. It can also be seen as being formed as a claw or pin, where a hole is provided in the end of the pin. The perforating end may be sharp and capable of perforating the corresponding pouch cell. Through the provision of the second channel 30, fluid can flow between the outside and inside of the pouch cell. As can be seen in Figures 2 and 3, the second openings 28 of the perforation elements 24A, 24B, 24C, 24D, 24E, and 24F are also openings in the wall of the first fluid channel.

[0054] As shown in Figures 2 and 3, the perforated elements 24A, 24B, 24C, 24D, 24E, and 24F are held adjacent to the corresponding pouch cells 14A, 14B, 14C, 14D, 14E, and 14F by a holding structure, with their perforated ends PE facing the corresponding pouch cells. It can also be seen that the perforated elements are provided at a distance from the corresponding pouch cells. In this example, they are displaced horizontally from the corresponding pouch cells. The pouch cells are expandable in at least one direction, one of which is toward the corresponding perforated element. The displacement described above is selected to accommodate some degree of expansion of the corresponding pouch cells during thermal runaway TR. In the first embodiment, the perforated elements are also fixedly attached to the holding structure 13. More specifically, the second openings 28 of each perforated element 24A-24F are openings in the inner wall of the first fluid channel 20. As a result, each second fluid channel 30 is in fluid communication with the first fluid channel 20.

[0055] When the pouch cell experiences thermal runaway TR, gas is generated inside the pouch cell, causing it to expand. Due to the pouch cell being sandwiched between a pressure plate and an insulating plate, expansion can only occur horizontally. Additionally, the housing 12 can restrict expansion at the end opposite the first fluid channel 20. This allows the pouch cell to expand only toward the first fluid channel 20.

[0056] Figure 3 schematically illustrates this case for the first pouch cell 14A. The first pouch cell 14A expands toward the first fluid channel 20 due to thermal runaway TR. Additionally, it can be seen that the first pouch cell 14A expands so much that it collides with the first perforating element 24A, thereby causing the first perforating element 24A to perforate the first pouch cell 14A. As a result, the gas inside the pouch cell 14A is released into the first fluid channel 20 through the second fluid channel 30 and then led away from the pouch cell, for example, out of the housing 12.

[0057] In this way, it can be seen that an explosion is avoided. Additionally, it is easy to implement in that no moving parts are used, which simplifies the structure and reliability of the electrochemical device. There is also good control over the perforation operation. The use of a retaining structure to which at least the first pouch cell is connected provides, additionally, control over the expansion of the pouch cell. The use of fixed locations for the perforation element can also provide a precise selection of which part of the pouch cell should be perforated in the event of thermal runaway, while the use of a second fluid channel can be used to control the flow of gas from the perforated pouch cell.

[0058] The electrochemical device according to the first embodiment can also be described as follows:

[0059] Pouch cells 14A-14F are stacked together, and the insulating layers 22A-22E are located between the two larger surface pouch cells to avoid heat transfer. Perforating elements or claws 24A-24F are positioned toward the sides of the pouch or the expected discharge locations. The claws have sharp edges and an internal hollow structure, and for example, have a volcanic shape as shown in Figures 2, 3, and 4. The module frame 13 is designed to have a pressurized area PA and a low-pressure area LPA. The low-pressure area LPA is the cell-side region facing the claws 24A-24F. During thermal runaway, the overworked cell 14A has a rapid internal pressure buildup. The gas species will first accumulate in the low-pressure area LPA, resulting in a bulge on the cell side within that area. The bulging cell side or expected discharge location (e.g., the seal near the tab, which is the mechanically weakest point on the cell container) will first come into contact with the claws 24A, resulting in discharge. The emitted gas will pass through the hollow tube of the claw portion 24A, enter the exhaust channel 20, and be exhausted to the outside of the module / pack in a controlled manner. A CO, H2, or CO2 sensor may be located at the outlet of the exhaust channel to provide a warning signal.

[0060] A second embodiment of the electrochemical device 10B is described hereby with reference to Figures 5, 6, 7, and 8, where Figure 5 shows a perspective view of an electrochemical device comprising a housing in which pouch cells are stacked in several stack layers separated by support plates; Figure 6 shows a top view of two pouch cells in a first layer of the stack provided on a support plate, with the first edge of the support plate folded over the first edge of the pouch cells in the first layer; Figure 7 shows a side view of the first and second layers of the stack inside the housing, where the first edge of the first support plate is folded over the first edge of the pouch cells in the first layer, the second edge of the first support plate is folded over the second edge of the pouch cells in the second layer, and a second type of perforating element is provided on the folded edge; and Figure 8 shows the same side view as in Figure 7, where a pouch cell in the second layer experiences thermal runaway and is perforated by the corresponding perforating element.

[0061] In this case, there are pouch cell stacks provided in several layers. For example, each layer of the stack comprises two pouch cells that can be electrically interconnected. Figure 5 shows the first and second pouch cells 14A1 and 14A2 in the first layer, the second pouch cell 14B2 in the second layer, the first and second pouch cells 14C1 and 14C2 in the third layer, the second pouch cell 14D2 in the fourth layer, the first and second pouch cells 14E1 and 14E2 in the fifth layer, the second pouch cell 14F2 in the sixth layer, the first and second pouch cells 14G1 and 14G2 in the seventh layer, and the second pouch cell 14H2 in the eighth layer. The first pouch cell 14B1 in the second layer is then shown in Figures 7 and 8.

[0062] Furthermore, there are several support plates 32A, 32B, 32C, and 32D, between which layers are stacked. In this case, one support plate is provided for two layers of the stack. The pouch cells of the layer can be joined to the support plate through hemming. The edges of the support plate can then be folded over the edges of the pouch cells of the layer. For example, the first support plate 32A is provided between the first layer of pouch cells 14A1 and 14A2 and the second layer of pouch cells 14B1 and 14B2. Next, the first edge of the first support plate 32A folds over the first edges of the pouch cells 14A1 and 14A2 in the first layer along the direction from the first electrical terminal 16A1 of the first pouch cell 14A1 to the first electrical terminal 16A2 of the second pouch cell 14A2, and the second edge of the first support plate 32A folds around the second edges of the pouch cells 14B1 and 14B2 in the second layer of pouch cells. The first fluid channels 20A and 20B may be provided in this case as a primary first fluid channel 20A between the first support plate 32A and the first edges of the pouch cells 14A1 and 14A2 in the first stack layer, and as a secondary first fluid channel 20B between the first support plate 32A and the second edges of the pouch cells 14B1 and 14B2 in the second stack layer. The first fluid channels are located between these overlapping edges and are also provided for the transfer of fluid to or from the pouch cell. In this example, they are discharge channels for transferring gas from the pouch cell.

[0063] Furthermore, here there are more than one pouch cell in the electrochemical device, and each pouch cell has a perforating element. In addition, the first fluid channel passes alongside each perforating element.

[0064] The pouch cells are also provided in at least one stack, where each layer of the stack comprises at least one pouch cell, where in this example, each layer comprises two pouch cells. In this case, additionally, another edge of the support plate may fold over the second edge of the pouch cell of the corresponding second stack layer, or vice versa.

[0065] Here, a module pack / frame 13 may also be present, which provides pressure P on the stack layer. The module pack / frame 13 may be part of the holding structure and is an element that applies pressure to the pouch cell to restrict the possible directions of expansion. Different first fluid channels may also be connected to further discharge channels (not shown) on the pack frame 13.

[0066] Furthermore, perforation elements are also provided in the area where the first support plate 32A is folded over the pouch cell. Thus, there is a first perforation element 24A1' provided on the first support plate 32A in the area facing the first edge of the first pouch cell 14A1 of the first layer, and a second perforation element 24B1' for the first pouch cell 14B1 of the second layer in the area facing the second edge of this cell 14B1.

[0067] In this case, the safety device comprises a holding structure in the form of a support plate, the support plate equipped with a perforating element held adjacent to the corresponding pouch cell, the perforating end of which faces the corresponding pouch cell. The pressure applied by the module / pack frame 13 limits the number of permissible directions in which the pouch cells can expand. However, they are clearly capable of expanding in the direction toward the corresponding perforating element.

[0068] As can be seen from the above, the retaining structure provided with the perforation element may also include support plates 32A, 32B, 32C, and 32D that similarly help to provide the first fluid channel. However, in this embodiment, it is also possible that the module / pack frame 13 is not actually part of the retaining structure.

[0069] Furthermore, the perforating elements 24A' and 24B' may be of a second type that does not include a second channel. The perforating elements may, for example, be pins or claws shaped as cones.

[0070] For example, as before the thermal runaway that occurs in the first pouch cell 14B1 of the second layer in Figure 8, the pouch cell 14B1 is expanded toward the corresponding perforating element 24B' so that the perforating element perforates the pouch cell at the perforating end when the pouch cell expands along this direction of expansion. This releases the gas inside the pouch cell into the corresponding first fluid channel.

[0071] Figures 5-8 illustrate the vent and exhaust channel design of a pouch battery module / pack based on a hemming structure. One edge of the pouch cell is hemmed on a support plate (made of a material such as metal, polymer, etc.). Two pouch cells may be attached to two sides of the support plate and hemmed. Claws are located within the hemming structure and face the pouch cell. At the onset of thermal runaway, the bulging of the cell leads to an increase in cell volume, deforming the hemming structure, which reduces the distance between the pouch or bag and the claws. If thermal runaway continues, the claws will puncture the pouch or bag, and exhaust gases will be released from the cell and enter a first fluid channel formed by the hemming structure. Such a first fluid channel can therefore serve as an exhaust channel, guiding the exhaust gas flow to the exhaust section.

[0072] Figures 9, 10A, and 10B show an electrochemical device according to a third embodiment, where Figure 9 is a top view of an electrochemical device 10C that includes a pouch cell and does not have a perforating element, where the corners of the electrochemical device are shown in more detail, where Figure 10A is a cross-sectional view of the corners of the electrochemical device, and Figure 10B is a top view of the corners.

[0073] In this third embodiment, the pouch cell 14A is located inside the housing into which the pouch cell is hemmed. Thus, there is a hemming structure used to fasten the pouch cell to the housing. In this case, the retaining structure surrounds the pouch cell 14A and may further comprise first and second pieces 42, 44, each having a first edge, where the first edge of the first piece 42 is folded around the first edge of the second piece 44, or vice versa, to form a first mechanical connection. In this example, the first edge of the second piece 44 is folded around the first edge of the first piece 42. Furthermore, a perforating element is further positioned between the pouch cell and the retaining structure, adjacent to the first mechanical connection.

[0074] The first and second pieces may be made of metal. Alternatively, they may be made of ceramic or polymer material.

[0075] In this case, the third type of perforation element 24A'' is provided inside the hemming structure used for the pouch cell 14A. Thus, a housing for the pouch cell exists, which has first and second pieces 42, 44, where the edge of the second piece 44 folds over the edge of the first piece 42 to form a mechanical connection. The mechanical connection runs along at least the entire long side of the electrochemical device 10C, which extends between the first electrical terminal 16A and the second electrical terminal 18A of the pouch cell. The pouch cell 14A is then placed inside the housing formed by the two pieces 42, 44.

[0076] In the area adjacent to the mechanical connection, the housing has a shoulder or raised section, the raised section extending along the previously described long side. There is also a layer of insulation 40 between the pouch cell 14A and the first and second pieces 42, 44, the insulation 40 is attached to the casing and extends into the mechanical connection.

[0077] The pouch cell also extends into the raised section. However, it does not completely fill the raised section. As seen in Figure 10A, the pouch cell 14A is more or less aligned with the second piece 44 of the housing in the raised section, but not with the first piece 42. There is a space between the pouch cell 14A and the first piece 42, which has the thermal insulation 40 in the raised section. In this space is provided a third type of perforating element 24A'' embedded in the polymer, where a portion of the polymer forms a knife block 46, which is also a retaining structure for the perforating element 24A''. The thermal insulation 40 and at least the first piece 42 of the housing can also be considered part of the retaining structure. The perforating element 24A'' also has a second fluid channel, here having first and second openings, where the first opening is located in the knife edge. As can be seen from Figure 10B, the second opening is therefore located on the outside of the housing.

[0078] The portion of the pouch cell 14A located within the raised section is also filled with thermal insulation material 34 or thermal sealing material.

[0079] However, a cavity or pocket 36 is provided in the insulation material 34, and the pocket is aligned adjacent to the perforation element 24A''. It can be seen that a portion of the polymer between the perforation element 24A'' and the first piece 42 is used to form a knife block together with the portion of polymer aligned with the insulation material 34 between the pocket and the mechanical connection.

[0080] In this case, the electrochemical device comprises only one pouch cell having a safety device that includes a holding structure in the form of a knife support 46 that holds a perforating element 24A'' which is held adjacent to the pouch cell 14A by a holding structure and whose perforating end faces the corresponding pouch cell. The pouch cell 14A is also attached to the holding structure by being attached to a knife block.

[0081] The pressure applied by the first and second pieces 42, 44 restricts the possible directions of expansion of the pouch cell. The only place where the pouch cell 14A can expand is in the raised section, and this expansion will be most pronounced in the pocket 36. From this, the pouch cell 14A in the pocket can be expanded toward the knife edge. Thereafter, in the event of thermal runaway, the pouch cell will collide with the perforating element 24A'' and be perforated. The gas in the pouch cell 14A will then be released through the second fluid channel, possibly into the first fluid channel located outside the hemming structure.

[0082] According to a variant of the second embodiment of the electrochemical device, it is possible to combine discharge and cooling. An example of this is shown in Figure 11, which shows the same diagram as in Figure 7. Here again, there is a first support plate 32A provided for two layers of pouch cells in the stack. The first support plate 32A is provided on the top surface of the pouch cells 14A1 of the first layer and may have a meandering structure that starts from the second edge of these pouch cells 14A1 of the first layer, then folds over the first edge of the pouch cells 14A1 of the first layer, passes between the pouch cells 14A1 of the first layer and the pouch cells 14B1 of the second layer, folds around the second edge of the pouch cells 14B1 of the second layer, and then passes to the first edge of the pouch cells 14B1 of the second layer.

[0083] Perforating elements 24A', 24B' and first fluid channels 20A, 20B, which are also of the second type, may be provided in the area where the first support plate 32A is folded around the first edge of the pouch cell 14A1 of the first layer, and in the area where the first support plate 32A is folded around the second edge of the pouch cell 14B1 of the second layer. Furthermore, cooling channels 50A, 50B, 50C may be provided in the first support plate 32A. The first cooling channel 50A may be above the first layer of the pouch cell, the second cooling channel 50B may be between the two layers of the pouch cell, and the third cooling channel 50C may be below the second layer of the pouch cell.

[0084] The cooling fluid can flow through the cooling channel to cool the support plate, pouch cell, and first fluid channel.

[0085] Another variation of the use of cooling is shown in Figures 12, 13, and 14, where Figure 12 is a perspective view of a pouch cell having a cooling plate with cooling channels, Figure 13 is a side view of a pouch cell having a cooling plate with cooling channels, and Figure 14 is a side view of a pouch cell having cooling channels when the pouch cell has experienced thermal runaway and has been perforated by a corresponding perforating element, which is a variation of the first type.

[0086] In this modified configuration, the cooling plate 51 is attached to the pouch cell 14A. A first fluid channel 50A, which is a cooling channel for the cooling fluid, is provided in the cooling plate 51 between the first electrical terminal 16A and the second electrical terminal 18A. The first fluid channel 50A is thus part of the retaining structure. Modified forms of the first type of perforated elements 24A1, 24A2, which have a second fluid channel, are provided on the wall of the cooling channel. Thus, the cooling plate also forms a retaining structure for the perforated elements 24A1, 24A2. Furthermore, a thermal film 52 is provided between the pouch cell 14A and the retaining structure. In this case, the thermal film 52 is provided in the second fluid channel and prevents fluid flow between the first and second openings of the perforated element. The first fluid channel 50A, the perforating elements 24A1 and 24A2, and the heat-sensitive film 52 together form an introduction system and a trigger mechanism for bringing a cooling fluid or flame retardant from the first fluid channel 50A into the pouch cell 14A (for example, to the center of the pouch cell) for fire extinguishing purposes.

[0087] As shown in Figure 13, the perforating element is provided in the wall of the first fluid channel 50A and has a perforating end with a first opening facing the first pouch cell 14A. Thus, the second opening of the perforating element is also an opening in the wall of the first fluid channel 50A. In this case, the perforating element comprises first and second pins 24A1, 24A2 separated from each other by a distance defining the first opening and the second fluid channel. The film 52 is heat-sensitive and will break at high temperatures, for example, up to 90°C. Severe pressure buildup (volume expansion) inside the pouch cell 14A can press the pouch or bag against the sharp edges of the perforating elements 24A1, 24A2, triggering perforation of the pouch 14A. High-temperature exhaust gases break the film, thereby allowing the cooling fluid CF or flame retardant FR to enter the pouch cell 14A. This indicates that the inflated, high-temperature pouch cell ruptures the heat-sensitive film when it expands along the direction of expansion toward the perforating element.

[0088] In this case, it is found that there is a safety device for one pouch cell 14A, where the holding structure is formed by a cooling plate 51 having a first fluid channel 50A, and which holds the perforating elements 24A1, 24A2. The pouch cell 14A is expandable in more than one direction. However, it is also clear that one of these directions in which the pouch cell 14A can expand is toward the perforating elements 24A1, 24A2, which are held adjacent to the pouch cell and whose perforating ends face the pouch cell, such that the perforating elements perforate the pouch cell at their perforating ends when the pouch cell expands toward the perforating elements.

[0089] It should be noted that the embodiments described above are used to introduce a cooling fluid and / or flame retardant into the pouch cell 14A, but can also be used to discharge gases from the pouch cell 14A to the outside.

[0090] Another variation of the use of cooling is shown in Figures 15, 16, and 17, where Figure 15 schematically shows a side view of a fourth type of perforating element, Figure 16 shows a side view of a fourth type of perforating element used with a pouch cell and a first fluid channel, and Figure 17 shows a side view of a fourth type of perforating element, a pouch cell, and a first fluid channel when the pouch cell experiences thermal runaway and is perforated by the perforating element.

[0091] In this modified form, the perforating element 24A''' comprises a tip 54 joined to a body 56, where the tip has a first opening 26 of a second fluid channel 30 at the perforating end PE, and the body 56 has a base providing a bottom end BE. The body 56 also comprises a second opening 28. The second fluid channel 30 may be angled such that the second opening 28 is located in the side surface of the body 56 between the perforating end PE and the bottom end BE. The body 56 may be formed as a cylinder having one radius, while the tip 54 may be formed as a cylinder having a smaller radius joined to a frustocone. The first opening 26 may be located at the tip of the frustocone, while the second opening is located on the side surface of the body cylinder. The first opening 26 is again located at the perforating end PE. However, the second opening is not located at the bottom end BE. Instead, the other end of the perforating element is the side surface of the body 56.

[0092] As shown in Figure 16, the body 56 of the perforating element 24A'' may be fastened to a first location on the inner wall of the first fluid channel 50A via a first elastic element 58, and the tip 54 of the perforating element 24A'' may be fastened to the pouch cell via a second elastic element 60, where the inner wall is the inner wall of the first fluid channel 50A at the furthest distance from the pouch cell 14A, thereby positioning the first elastic element 58 inside the first fluid channel 50A. Thus, the perforating element 24A'' is also attached to the retaining structure via the first elastic element 58, and the pouch cell 14A is attached to the perforating element 24A'' via the second elastic element 60. The channel connection is also joined to the first fluid channel 50A, and its channel connection is located on the opposite side of the first location. The perforating element 24A'''' is positioned in a channel connection that leads into the first fluid channel 50A and is movable back and forth relative to the first location and pouch cell 14A.

[0093] In this modified form, the first fluid channel 50A is part of a cooling plate (not shown) to which the pouch cell is attached. The first fluid channel 50A is also, in this case, part of a retaining structure for the perforating element 24''', which may also include a cooling plate.

[0094] In normal operation, the body 56 of the perforating element 24A'' is completely located inside the channel connection portion having a wall that provides a seal for the body 56, thereby preventing fluid from passing through the perforating element 24A'' during normal operation. This is the first position of the perforating element where the second opening is separated from the first fluid channel.

[0095] A cooling plate having a first fluid channel 50A is thus attached to the pouch cell 14A. There is an introduction system for introducing a cooling fluid CF or flame retardant FR into the pouch cell 14A (e.g., at the center position) for fire extinguishing. The introduction system includes elastic elements 58, 60 such as springs and a perforating element 24A'''. Severe pressure buildup (volume expansion) inside the pouch cell 14A may lead to pressing the elastic elements, which can trigger the perforating element to move to a second position where a second opening is in fluid contact with the first fluid channel. Thereafter, the second opening 28 is positioned inside the first fluid channel 50A. The movement of the pouch cell 14A also causes the tip 54 of the perforating element 24A' to perforate the pouch film. As a result, the expansion of the pouch cell moves the perforating element from a first position in the channel connection to a second position where at least a portion of the body 56, which has a second opening 28, is located inside the first fluid channel 50A. The cooling fluid CF or flame retardant FR can then enter the pouch cell 14A through the second fluid channel 30 in the perforating element 24A'. The expansion of the pouch cell then moves the perforating element in the direction of expansion so that the second opening enters the first fluid channel.

[0096] Thus, in this case as well, it can be seen that there is a safety device for one pouch cell 14A, in which the holding structure is formed by a cooling plate (not shown) having a first fluid channel 50A, and holds the perforating elements 24A1, 24A2. The pouch cell 14A is expandable in more than one direction. However, it is also clear that one of these directions in which the pouch cell 14A is expandable is toward a perforating element 24A''' that is held adjacent to the pouch cell and whose perforating end faces the pouch cell, such that the perforating element perforates the pouch cell at its perforating end when the pouch cell expands toward the perforating element.

[0097] Please be aware that this modified form can be used instead for gas discharge.

[0098] Unlike prismatic or cylindrical cells, pouch cells lack safety vents, which pose safety concerns due to severe internal pressure buildup during thermal runaway. Aspects of this disclosure are directed toward providing pouch cells with safety vents.

[0099] Further variations of the electrochemical device equipped with a safety vent in the pouch cell are shown in Figures 18 and 19, where Figure 18 is a perspective view of yet another embodiment of the electrochemical device, where the retaining structure for the perforation element is provided as an exhaust tape attached to the pouch cell, and Figure 19 is a top view of the pouch cell having the exhaust tape.

[0100] In this case, the retaining structure is therefore a tape 66 attached to or fastened to the pouch cell 14A. As can be seen in the figure, the tape 66 has a cavity in the bottom where the first type of perforating element 24A is provided. The cavity also has a hole in the bottom facing the first fluid channel 20, which in this case is a discharge channel. The hole in this cavity occupies the same space as the second opening of the perforating element 24A. Furthermore, there is a second elastic element 60 provided between the pouch cell 14A and the perforating element 24A or the bottom of the cavity. Therefore, the pouch cell is attached to the perforating element or retaining structure via the second elastic element.

[0101] This allows the safety vent to be integrated onto a tape that can be attached to a conventional pouch cell. The location of such an discharge tape can be any location on the pouch film (for example, in the center).

[0102] The perforating element is connected to an elastic element such as a spring, and to an discharge cover or tape.

[0103] • A second fluid channel is present in the perforation element, allowing gas or liquid to flow.

[0104] • The discharge hole is located on the discharge cover or discharge tape, i.e., at the bottom of the cavity.

[0105] Due to mechanical pressure, a discharge cover or discharge tape is attached to the pouch cell.

[0106] Under normal conditions, the elastic element 60 is not pressed against the surface, or is only partially pressed, thus avoiding direct contact between the perforating element 24A and the pouch film 14A.

[0107] Under severe operating conditions and in the first state of thermal runaway, the rapidly expanded pouch cell can further press against the elastic element 60 until it reaches the tip of the perforating element 24A.

[0108] When the pouch film reaches the perforation element 24 and is perforated thereby, an exhaust event occurs. The exhausted gas will be vented through the exhaust channel.

[0109] In this case, there exists an electrochemical device comprising a pouch cell and a safety device comprising a holding structure in the form of a safety discharge tape having a perforating element held adjacent to the pouch cell by a holding structure, with its perforating end facing the pouch cell. The pouch cell can expand in several directions. However, it is also clear that one of these directions is toward the perforating element, such that when the pouch cell expands along this direction of expansion, the perforating element perforates the pouch cell at its perforating end.

[0110] Figures 20 and 21 show modified forms of the discharge cover or discharge tape 66. Figure 20 shows a top view of a pouch cell having a discharge tape with a thermal film, and Figure 21 shows a top view of a pouch cell having a discharge tape with a thermal film between the pouch cell and the holding structure when the pouch cell experiences thermal runaway and is perforated by a perforating element.

[0111] The retention structure may be a tape fastened to the pouch cell.

[0112] In this case, the perforating element 24A is joined to the bottom of the cavity via a first elastic element 58 such as a spring. Thus, the perforating element 24A is attached to the holding structure via the first elastic element 58. There is also a thermal film 52 between the pouch cell 14A and the holding structure. In this case, the film 52 covers the entire perforating element 24A. As a result, the perforating element 24A is pressed by the thermal film 52 toward the discharge hole 70 in the bottom of the cavity. In this case, the thermal film 52 is placed between the perforating end of the perforating element and the pouch cell so that it softens due to the heat emitted from the pouch cell 14A, releasing the perforating element 24A and allowing it to move toward the pouch cell.

[0113] This embodiment can also be described as follows:

[0114] The discharge cover or discharge tape 66 does not require mechanical pressure at its top.

[0115] The elastic element 58 is attached to the perforating element 24A and pressed partially or completely against it.

[0116] A film 52 is placed between the perforating element 24A and the pouch cell 14A to avoid direct contact between the perforating element 24A and the pouch cell and to maintain mechanical pressure from the pressed elastic element 58.

[0117] When the pouch cell 14A is deformed to a certain extent due to rapid accumulation of internal pressure, the tension developed on the film 52 results in weaker mechanical strength and release of the perforating element 24A. The accelerated perforating element 24A will pierce the pouch film and enable the ejection function.

[0118] When the pouch cell 14A is under heavy use and in the initial stages of thermal runaway, the cell temperature increases dramatically (for example, up to 90°C). The film 52 will be destroyed due to the high temperature, and the released perforating element 24A will pierce the pouch film and enable the ejection function.

[0119] The discharge hole 70 at the bottom of the cavity can face or be connected to the discharge channel 20, allowing exhaust gas to be discharged through the discharge channel 20.

[0120] Figures 22, 23, 24, 25, and 26 show a hybrid pouch-prismatic cell design that combines multiple safety features.

[0121] In a further variant of the electrochemical device 10D shown in Figure 22, there is a housing that encloses two pouch cells connected in parallel to each other. The housing also has an inlet / outlet 72 for cooling and / or discharge. The inlet / outlet may be connected to a second fluid channel inside the casing, for example, in the form of a cooling channel in a cooling plate provided between the two pouch cells. In this case, the first and second electrical connection terminals of the electrochemical device are located on the same side of the housing.

[0122] Figure 23 shows another variant of the electrochemical device 10E, which similarly has a housing covering two pouch cells connected in parallel to each other. The housing also has an inlet / outlet 72 for cooling and / or discharge. In this case, the first and second electrical connection terminals of the electrochemical device are provided on both sides of the housing.

[0123] Figure 24 shows a modified form of the electrochemical device 10F, in which there are combinations of two pouch cells connected in series inside the housing and two pouch cells connected in parallel.

[0124] Figure 25 shows yet another variation of the electrochemical device 10G, which has eight pouch cells, four of which are connected in series and two in parallel.

[0125] The different modification forms shown in Figures 22-25 have the following advantages.

[0126] One, two, or more pouch cells may be sealed inside a case / housing (e.g., a conventional prismatic cell housing).

[0127] • There are inlets and outlets on the case / housing for connection to the cooling pipes.

[0128] The case / housing is filled with a continuously flowing cooling fluid or flame retardant.

[0129] The pouch cell is immersed in a cooling fluid or flame retardant.

[0130] Figure 26 shows another variant of the electrochemical device 10H. In this case, there are several housings, each having two parallel pouch cells, as shown in Figure 22. These housings are arranged in two stacks. Furthermore, the inlets and outlets 72 of these housings are interconnected to allow the cooling fluid to flow through all the housings.

[0131] Figure 26 shows further integration into a large battery pack using the hybrid pouch-prismatic battery module / pack with the safety features described above.

[0132] Given the growth of the pouch cell, module, and pack markets, this disclosure addresses safety issues related to thermal runaway and resulting fire accidents in pouch cells. Novel methods for addressing thermal runaway, such as novel vents, discharge / fluid channels, and embedded fire suppression, have been designed to enable safe operation of pouch cells. Accordingly, this disclosure presents a variety of safety features that require less additional effort and are relatively low-cost for achieving high safety in pouch cells integrated into modules or packs.

[0133] From the above discussion, it is clear that the present invention can be modified in numerous ways. The schematic diagrams shown represent only illustrative embodiments, and the given list of embodiments should be considered non-limiting. Consequently, it should be recognized that the present invention is limited only by the following claims.

Claims

1. An electrochemical device (10A; 10B; 10C; 10D; 10E; 10F; 10G) comprising at least one pouch cell (14A, 14B, 14C, 14D, 14E, 14G1, 14G2, 14H2; 14A'; 14A; 14A''; 14A, 14B) and a safety device, wherein the safety device comprises a holding structure (13; 32A, 32B, 32C, 32D; 42, 44; 51; 66; 68A, 68B, 68C, 68D) and the holding structure An electrochemical device comprising at least one pouch perforating element (24A, 24B, 24C, 24D, 24E, 24F; 24A1', 24B1'; 24A''; 24A1, 24A2; 24A''', 24A', 24B') held adjacent to a corresponding pouch cell, with its perforating end (PE) facing the corresponding pouch cell, wherein each pouch cell is attached to the holding structure and is expandable in at least one direction, where one of the directions (DOE) is toward the corresponding perforating element so that the perforating element perforates the pouch cell at its perforating end.

2. The electrochemical device according to claim 1, wherein the retaining structure comprises at least one element (13; 32A; 32B, 32C, 32D; 42, 44) that applies pressure to at least one of the pouch cells to restrict the possible directions of expansion.

3. The electrochemical device according to claim 2, wherein the retaining structure comprises first and second pieces (42, 44) surrounding the pouch cell (14A'), each having a first edge, where the first edge of the first piece (42) is folded around the first edge of the second piece (44), or vice versa, to form a first mechanical connection, and the perforating element (24A'') is positioned between the pouch cell and the retaining structure adjacent to the first mechanical connection.

4. The electrochemical device according to claim 3, wherein the pouch cell (14A) is surrounded by an insulating material (34), the insulating material (34) having a cavity adjacent to the perforating element (24A''), from which the pouch cell (14A) can expand.

5. The electrochemical device according to any one of claims 1 to 4, further comprising a first fluid channel (20; 20A, 20B; 50A) for transferring fluid to or from the pouch cell.

6. The electrochemical device according to any one of claims 1 to 5, wherein the perforating element comprises a second fluid channel (30) extending between a first opening (26) provided at the perforating end (PE) and a second opening (28) provided at the other end of the perforating element, the second fluid channel enabling a fluid to flow between the outside and inside of the pouch cell.

7. The electrochemical device according to claim 6, dependent on claim 5, wherein the second opening (28) of the perforating element is also an opening in the wall of the first fluid channel (20; 50A).

8. The electrochemical device according to any one of claims 1 to 7, wherein the perforating elements (24A; 24A''; 24A') are attached to the holding structure (13; 66) via a first elastic element (58).

9. The electrochemical device according to any one of claims 1 to 8, wherein the pouch cell (14A) is attached to the perforating element (24A'') or the retaining structure (66) via a second elastic element (60).

10. The electrochemical device according to any one of claims 1 to 9, further comprising a thermal film (52) between the pouch cell (14A) and the holding structure (51; 66).

11. The holding structure comprises the first fluid channel (50A), the first elastic element (58) is positioned between the pouch cell (14A) and the inner wall of the first fluid channel (50A) furthest from the pouch cell (14A), and the expansion of the pouch cell (14A) moves the perforating element (24A'') from a first position to a second position, where the second opening (28) is separated from the first fluid channel (50A) in the first position and opens into the first fluid channel (50A) in the second position, according to claim 9, dependent on claim 6, dependent on claim 8, and dependent on claim 9.

12. The electrochemical device according to claim 10, dependent on claim 7, wherein the thermal film (52) is located in the second fluid channel (30) of the perforating element (24A1, 24A2) such that the thermal film (52) bursts when the pouch cell (14A) expands along the direction of expansion (DOE).

13. The electrochemical device according to any one of claims 1 to 10, wherein the retaining structure (66) is a tape fastened to the pouch cell (14A).

14. The electrochemical device according to claim 13, which is dependent on claim 8 and claim 10, wherein the heat-sensitive film (52) is provided between the perforating end (PE) of the perforating element (24A') and the pouch cell (14A) so as to be softened by heat emitted from the pouch cell (14A), releasing the perforating element (24A) and moving toward the pouch cell (14A).

15. If there are more than one pouch cell, the retaining structure (13) comprises a perforating element for each pouch cell, and the first fluid channel passes beside each perforating element, according to any one of claims 6 to 12, dependent on claim 1 or 2 and dependent on claim 5.

16. The electrochemical device according to claim 15, wherein the pouch cell is provided as at least one stack, where each layer of the stack comprises at least one pouch cell, and the holding structure comprises several support plates (32A, 32B, 32C, 32D), one for every two layers of the stack, where the edges of the support plates are folded over or over the edges of the pouch cell in the corresponding stack layer, and the first fluid channel is provided between these overlapping edges.

Images