Energy storage component and vehicle

Abstract

An energy storage component and vehicle are disclosed, relating to the field of battery technology. The energy storage component includes: a housing; battery cells disposed within the housing, the battery cells comprising a plurality of cells arranged in an array, a first space forming between the battery cells and the sidewalls of the housing, and a second space forming between the cells; a first potting portion, filling at least portions of the first and second spaces; the first potting portion comprising a first density region and a second density region sequentially from the bottom to the top of the housing, the second density region corresponding at least to the middle portion in the height direction of the cells, and the density of the second density region being higher than that of the first density region. The energy storage component provided by this disclosure is advantageous for improving the structural strength and rigidity of the energy storage component.

Description

Technical Field

[0001] This disclosure relates to the field of energy storage technology, and more specifically, to an energy storage component and a vehicle. Background Technology

[0002] Encapsulation technology is a key process in the manufacturing of energy storage components. Its core function is to use encapsulation materials to fix the internal battery cells of the energy storage component, providing functions such as heat dissipation, moisture protection, shock resistance, and insulation protection. However, the overall structural strength and rigidity of energy storage components in related technologies need further improvement. Utility Model Content

[0003] This disclosure provides an energy storage component and a vehicle, which is beneficial to improving the structural strength and stiffness of the energy storage component.

[0004] According to one aspect of this disclosure, an energy storage component is provided, comprising:

[0005] case;

[0006] A battery cell is disposed in a housing. The battery cell includes multiple cells arranged in an array. A first space is formed between the battery cell and the side wall of the housing, and a second space is formed between the cells.

[0007] The first potting portion fills at least a portion of the first space and the second space; the first potting portion includes a first density region and a second density region sequentially from the bottom to the top of the casing, the second density region corresponds at least to the middle part of the cell height direction, and the density of the second density region is higher than that of the first density region.

[0008] In one exemplary embodiment of this disclosure, the density of the first density region is 0.16–0.28 g / cm³. 3 ; and / or, the density of the second density region is 0.28–0.55 g / cm³. 3 .

[0009] In one exemplary embodiment of this disclosure, the ratio of the thickness D2 of the second density region to the thickness H of the first potting portion satisfies 0.65≤D2 / H≤0.85.

[0010] In one exemplary embodiment of this disclosure, the ratio of the distance H1 from the bottom of the second density region to the bottom of the first potting portion to the thickness H of the first potting portion satisfies 0.05≤H1 / H≤0.15.

[0011] In one exemplary embodiment of this disclosure, a first transition region is formed at one end of the second density region near the first density region; the density of the first transition region increases from bottom to top.

[0012] In one exemplary embodiment of this disclosure, a first skin layer is provided at the bottom of the first density region, and the first skin layer is attached to the bottom wall of the shell; the density of the first skin layer is greater than that of the first density region.

[0013] In one exemplary embodiment of this disclosure, a third density region is provided on top of the second density region, and the density of the third density region is less than that of the second density region.

[0014] In one exemplary embodiment of this disclosure, a front cavity, a first side cavity, a rear cavity, and a second side cavity are formed between the battery cell and the four side walls of the casing, respectively; the first potting portion fills at least one of the front cavity, the first side cavity, the rear cavity, and the second side cavity.

[0015] In one exemplary embodiment of this disclosure, the battery cells are arranged in an array along a first direction and a second direction, a first side gap is formed between the battery cells arranged along the first direction, and a first potting portion fills at least one of the first side gaps.

[0016] In one exemplary embodiment of this disclosure, a second side gap is formed between the cells arranged in an array along a second direction, and a first potting portion fills at least one of the second side gaps.

[0017] In one exemplary embodiment of this disclosure, the energy storage component includes an integrated busbar and a second potting portion. The integrated busbar is disposed on the top of the battery cell and connected to the cell. The second potting portion at least fills the area between the top of the cell and the integrated busbar.

[0018] In one exemplary embodiment of this disclosure, the first potting portion and the second potting portion are formed by foaming and potting with the same potting material.

[0019] In one exemplary embodiment of this disclosure, the energy storage component includes a top cover and a third potting portion; the top cover is fastened to the top of the housing, and the third potting portion fills at least between the top of the battery cell and the top cover.

[0020] In one exemplary embodiment of this disclosure, the third potting portion has a central region and an edge region located around the central region, and the gap between the central region and the top cover is not greater than the gap between the edge region and the top cover.

[0021] In one exemplary embodiment of this disclosure, the distance between the top of the third potting portion and the bottom of the top cover gradually increases from the center of the top cover to the edge.

[0022] According to another aspect of this disclosure, a vehicle is provided that includes the energy storage component of any of the foregoing.

[0023] In the energy storage component disclosed herein, the density of the second density region is higher than that of the first density region, resulting in higher strength and rigidity in the middle of the cell's height direction. Under pressure, the second density region exhibits higher structural performance indicators such as compressive resistance and compressive modulus, improving the overall package and cell's resistance to mechanical damage. This also reduces the risk of thermal thinning and carbonization of the potting material in the second density region, as well as the risk of thermal diffusion and thermal runaway between adjacent cells. Conversely, the relatively lower density of the first density region helps save time initiating the potting material to form the first potting section, improving production efficiency and reducing the overall amount of potting material used, thus contributing to weight reduction in the energy storage component.

[0024] The vehicle disclosed herein exhibits enhanced safety due to the strong resistance of the energy storage components and battery cells to mechanical damage. Furthermore, the reduced risk of thermal runaway caused by thermal diffusion due to the decreased heat thinning and carbonization of the potting material in the second density region also contributes to improved vehicle safety. Additionally, the relatively low density of the first density region saves time in forming the first potting section, increasing vehicle production efficiency and reducing the overall amount of potting material used, thus contributing to vehicle weight reduction.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0027] Figure 1 This is a schematic diagram of an exemplary embodiment of the energy storage component disclosed herein.

[0028] Figure 2 This is a schematic diagram illustrating an exemplary embodiment of the energy storage component disclosed herein from another perspective.

[0029] Figure 3 This is a schematic diagram of the assembly of individual cells and a liquid cooling plate to form a battery cell in one exemplary embodiment of the energy storage component disclosed herein.

[0030] Figure 4 This is a schematic diagram of the first potting section in an exemplary embodiment of the energy storage component disclosed herein.

[0031] Figure 5 This is a schematic diagram of the second filling region in an exemplary embodiment of the energy storage component disclosed herein.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Shell; 101. Front cavity; 102. First side cavity; 103. Rear cavity; 104. Second side cavity;

[0034] 2. Battery cell; 21. Battery cell; 201. First side gap; 202. Second side gap; 22. Liquid cooling plate; 23. Integrated busbar; 24. Liquid cooling pipe;

[0035] 31. First density zone; 32. Second density zone; 321. First transition zone; 33. Third density zone; 41. First crust layer; 42. Second crust layer; 5. Top cover. Detailed Implementation

[0036] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0037] Unless otherwise specified or stated, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “a,” “an,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “comprising” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to those listed; the terms “first” and “second” are used only as illustrative marks and are not intended to limit the number, importance, or order of the objects.

[0038] The terms “connection” and “fixation” should be interpreted broadly. For example, unless otherwise specified, “connection” can be a fixed connection, a movable connection, an integral connection, or a detachable connection. It can be a direct connection or an indirect connection through an intermediate medium.

[0039] Furthermore, in this application, directional terms such as "upper" and "lower" are used only to indicate relative positional relationships. For example, for convenience, they are defined according to the commonly understood orientation of energy storage components, or relative to the schematic placement of components in the accompanying drawings. For instance, the upper cover 5 is located on top of the housing 1, and the battery unit 2 is installed inside the housing 1, with the height direction being from bottom to top. It should be understood that these directional terms are relative concepts and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0040] According to one aspect of this disclosure, an energy storage component is provided, comprising:

[0041] Casing 1,

[0042] Battery unit 2 is disposed in housing 1. Battery unit 2 includes multiple cells 21 arranged in an array. A first space is formed between battery unit 2 and the side wall of housing 1, and a second space is formed between cells 21.

[0043] The first potting portion fills at least a portion of the first space and the second space; the first potting portion includes a first density region 31 and a second density region 32 sequentially from the bottom to the top of the housing 1, and the second density region 32 corresponds at least to the middle part of the cell 21 in the height direction. The density of the second density region 32 is higher than that of the first density region 31.

[0044] refer to Figure 1 An exploded view of an energy storage component is shown. A receiving cavity is formed within the housing 1, into which a battery cell 2 can be installed. The battery cell 2 includes multiple cells 21 arranged in an array, and may have an integrated busbar 23 (CellsContact System, CCS) on top to enable series and parallel connection between the cells 21 and to perform functions such as temperature and voltage sampling. The energy storage component may include a top cover 5, which can be fastened to the top of the housing 1 to enclose the battery cell 2 within the receiving cavity.

[0045] After the battery unit 2 is installed in the housing 1, a first space is formed between the battery unit 2 and the side wall of the housing 1, and a second space is formed between the cells 21. By filling part or all of the first space and the second space with potting material, it foams and forms a first potting part, which can improve the overall structural strength and rigidity of the energy storage component.

[0046] The energy storage component disclosed herein can be, for example, a power battery pack for a vehicle, or a battery system in an energy storage field or a land or water transport electric vehicle. The inventors discovered that during charge-discharge cycles of the prismatic cell 21, the reversible and irreversible expansion is most severe in the central region of the cell 21 along its height, especially the central region of the large facet, resulting in the greatest compressive force with the potting material. Under extreme thermal runaway conditions, disassembly of the battery revealed that the bulging is most pronounced in the central region of the large facet and side of the cell 21. High pressure coupled with high temperature can lead to thinning and carbonization failure of the potting material, resulting in heat diffusion. Furthermore, in collisions and compressions of energy storage components, such as those involving a vehicle carrying a power battery pack, the deformation is typically greatest in the central region of the large facet or side of the cell 21. However, during the natural foaming process of potting materials, as the potting materials undergo chemical reactions and foaming, their temperature gradually increases and the foaming speed gradually accelerates. This results in a higher density in the contact area between the bottom and the shell 1, while a lower density area is formed in the middle height position. The foaming ratio of the potting material in this area is high, resulting in a softer foam with a low compression modulus. Under extrusion or impact load conditions, it is more likely to deform and crush.

[0047] In the energy storage component disclosed herein, the first potting section includes a first density region 31 and a second density region 32 sequentially from the bottom to the top of the housing 1. The density of the second density region 32 is higher than that of the first density region 31. The second density region 32 corresponds at least to the middle part of the cell 21 in the height direction, thus providing higher strength and hardness in the middle part of the cell 21 in the height direction. When the second density region 32 is under pressure, its structural performance indicators such as compressive resistance and compressive modulus are higher, which can improve the overall ability of the energy storage component and the cell 21 to resist mechanical damage. At the same time, it reduces the risk of thermal runaway caused by thermal thinning and carbonization of the potting material in the second density region 32 due to heat. The relatively low density of the first density region 31 is beneficial to saving the time of potting material initiation to form the first potting section, improving production efficiency, and reducing the overall amount of potting material used, which is beneficial to reducing the weight of the energy storage component.

[0048] refer to Figures 2 to 3 This diagram illustrates a potting area within an energy storage component. The top view of the casing 1, with the main components inside, such as the battery cell 2 and integrated busbar 23, assembled and before the top cover 5 is fastened, is shown for reference. Figure 2 As shown in the diagram. A schematic diagram of the assembly of each battery cell 21 and the liquid cooling plate 22 to form the battery cell 2 is shown below. Figure 3 As shown in the figure, the X direction is the first direction and the Y direction is the second direction.

[0049] A first space is formed between the battery cell 2 and the side wall of the housing 1. Specifically, a front cavity 101, a first side cavity 102, a rear cavity 103, and a second side cavity 104 can be formed between the battery cell 2 and the four side walls of the housing 1, respectively. The first filling part can fill at least one of the front cavity 101, the first side cavity 102, the rear cavity 103, and the second side cavity 104. For example, the front cavity 101, the first side cavity 102, the rear cavity 103, and the second side cavity 104 are connected, and the first filling part can fill all of the front cavity 101, the first side cavity 102, the rear cavity 103, and the second side cavity 104.

[0050] A second space is formed between the 21 battery cells, for reference. Figure 3 As shown, the battery cells 21 are arranged in an array along the X and Y directions. Multiple first side gaps 201 are formed between the battery cells 21 arranged along the X direction. The second space may include some or all of the first side gaps 201, meaning that the first potting portion may fill at least one of the first side gaps 201. For example, the first potting portion fills all of the first side gaps 201. The battery cells 21 are also arranged in an array along the Y direction. Exemplarily, multiple second side gaps 202 can be formed between adjacent battery cells 21 in the Y direction, and the second space may include some or all of the second side gaps 202. A liquid cooling plate 22 may be provided between adjacent battery cells 21 in the Y direction to dissipate heat and cool the interior of the battery cell 2. The liquid cooling plate 22 is connected to a liquid cooling pipe 24.

[0051] For example, in one embodiment, a first filling portion is formed in the front cavity 101, the first side cavity 102, the rear cavity 103, the second side cavity 104, and all the first side gaps 201.

[0052] For example, in one embodiment, the first filling portion is formed only in the front cavity 101, the first side cavity 102, the rear cavity 103 and the second side cavity 104, and is not filled in the first side gap 201.

[0053] In one exemplary embodiment of this disclosure, the energy storage component further includes a second potting portion, which can fill the area between the top of the battery cell 21 and the integrated busbar 23. Specifically, the second potting portion can fill a large area of ​​irregularly shaped thin layer between the top cover of the battery cell 21 and the lower surface of the integrated busbar 23, serving to fix the battery cell 21 and assist in heat dissipation.

[0054] Both the first and second potting portions are formed by foaming and potting with a potting material. For example, the potting material may include polyurethane foam, silicone foam, epoxy resin foam, etc. After the potting material is poured in, it foams and expands within a certain time, filling the corresponding gaps within the energy storage component. Exemplarily, the first and second potting portions can be formed by foaming and potting with the same potting material. For example, the first and second potting portions can be integrally formed in a single foaming process.

[0055] In one exemplary embodiment of this disclosure, the energy storage component includes an upper cover 5 and a third potting portion; the upper cover 5 is fastened to the top of the housing 1, and the third potting portion fills at least between the top of the battery cell 2 and the upper cover 5. Exemplarily, the third potting portion is formed in the area from the upper surface of the integrated busbar 23 to the lower surface of the upper cover 5, which helps to improve the strength and heat dissipation performance of the top of the energy storage component. At the same time, the adhesiveness of the potting material in the third potting portion during the priming process bonds the bottom surface of the upper cover 5 to the housing 1 and the battery cell 2, which also helps to improve the firmness of the connection between the upper cover 5 and the housing 1.

[0056] For example, the third potting portion can be formed by foaming and potting the first and second potting portions with the same potting material. For instance, the first, second, and third potting portions can be integrally formed in a single foaming process. In other embodiments, the third potting portion can also be formed by filling in potting material and foaming after the first and second potting portions have been formed.

[0057] In one exemplary embodiment of this disclosure, the third potting portion has a central area and an edge area surrounding the central area. The gap between the central area and the top cover 5 is no greater than the gap between the edge area and the top cover 5. Specifically, taking the center point of the entire battery cell 2 as a reference, the central area can be a circle, ellipse, rectangle, or irregular shape with the center point as its centroid. The gap between the central area and the top cover 5 is smaller than the gap between the edge area and the top cover 5. This can be achieved by the central area being in contact with the bottom of the top cover 5, while the edge area is separated from the bottom of the top cover 5; or by the proportion of the area in contact between the central area and the bottom of the top cover 5 being greater than the proportion of the area in contact between the edge area and the bottom of the top cover 5. For example, in the horizontal plane at the top of the battery cell 2, the projected area of ​​the central area can account for 1 / 5 to 2 / 3 of the overall projected area of ​​the third potting portion. It should be noted that, due to the certain degree of randomness in the physicochemical process of the potting material foaming, and the inevitable process errors in the potting process, the concepts described in this disclosure, such as "center" and "in contact," should be understood as being within the range allowed by the manufacturing process precision.

[0058] In one exemplary embodiment of this disclosure, the distance between the top of the third potting portion and the bottom of the top cover 5 gradually increases from the center to the edge. For example, taking the center point of the entire battery cell 2 as a reference, the middle of the central area is in contact with the bottom of the top cover 5, and the gap between the top of the third potting portion and the bottom of the top cover 5 gradually increases from the center to the edge. This is beneficial for improving the strength of the central area at the top of the energy storage component, and also for improving the adhesion strength between the potting material and the central area of ​​the top cover 5.

[0059] In an exemplary embodiment of this disclosure, the density of the second density region 32 is higher than that of the first density region 31. For example, the density of the first density region 31 is 0.16–0.28 g / cm³. 3 This facilitates rapid expansion of the potting material, improves production efficiency, and reduces the overall amount of potting material used, thus reducing the weight of the energy storage components. The density of the second density zone 32 can be 0.28–0.55 g / cm³. 3 This is beneficial for improving the compressibility of the second density zone 32.

[0060] For example, the ratio of the distance H1 from the bottom of the second density region 32 to the bottom of the first potting part to the thickness H of the first potting part satisfies 0.05≤H1 / H≤0.15, which can help the second density region 32 to accurately correspond to the middle of the height direction of the large surface and side of the cell 21, thereby improving the overall strength of the middle position of the height direction of the cell 21 and enhancing the thermal runaway protection capability.

[0061] In one exemplary embodiment of this disclosure, reference is made to Figure 4 The diagram illustrates a schematic of the first potting portion. The thickness D2 of the second density region 32 can be a proportion of the thickness H of the first potting portion satisfying 0.65 ≤ D2 / H ≤ 0.85. For example, the ratio of the thickness D1 of the first density region 31 to the thickness H of the first potting portion can be 0 ≤ D1 / H ≤ 0.1. In one embodiment, the height of the first density region 31 ranges from 0 to 0.05H, and the height of the second density region 32 ranges from 0.05H to H.

[0062] In one exemplary embodiment of this disclosure, reference is made to Figure 4As shown, a third density zone 33 is provided at the top of the second density zone 32, and the density of the third density zone 33 is less than that of the second density zone 32. The relatively low density of the third density zone 33 is beneficial for saving the time required for the potting material to re-erupt, improving production efficiency, and reducing the overall amount of potting material used, thus contributing to weight reduction in the energy storage component. Furthermore, the viscosity of the potting material is related to the re-eruption time; the shorter the time from re-eruption to contact with the bonding surface, the higher its viscosity. The relatively low density of the third density zone 33 allows for a shorter time from re-eruption to contact with the bottom surface of the top cover 5, thereby improving the connection strength between the top cover 5 and the housing 1.

[0063] For example, the density of the third density region 33 may be close to the density of the first density region 31, such as being equal to the density of the first density region 31. Alternatively, the density of the third density region 33 may be greater than the density of the first density region 31 and less than the density of the second density region 32.

[0064] In one exemplary embodiment of this disclosure, the ratio of the thickness D3 of the third density region 33 to the thickness H of the first potting portion can be 0 ≤ D3 / H ≤ 0.2. For example, in one embodiment, the height range of the first density region 31 is 0 to 0.05H, the height range of the second density region 32 is 0.05H to 0.8H, and the height range of the third density region 33 is 0.8H to H.

[0065] In one embodiment, the density of the first density region 31 can be 0.16–0.28 g / cm³. 3 The compression modulus ranges from 30 to 170 MPa, and the hardness ranges from Shore A20 to Shore D30. The density of the second density region 32 can be 0.28 to 0.55 g / cm³. 3 The compression modulus ranges from 50 to 350 MPa, and the hardness ranges from Shore A 50 to Shore D 70. The density of the third density zone 33 can be 0.2 to 0.35 g / cm³. 3 The compression modulus ranges from 35 to 260 MPa, and the hardness ranges from Shore A40 to Shore D40.

[0066] In one exemplary embodiment of this disclosure, reference is made to Figure 5 As shown, a first transition region 321 is formed at the end of the second density region 32 near the first density region 31; the density of the first transition region 321 increases from bottom to top. For example, the density at the bottom of the first transition region 321 is the same as the density at the top of the first density region 31. Above the first transition region 321 is a density stabilizing region 322, and the density within the density stabilizing region 322 can be the same or within a relatively narrow range, for example, the density of the density stabilizing region 322 can be 0.4 to 0.55 g / cm³. 3The first transition zone 321 forms a transition between the first density zone 31 and the second density zone 32, which is beneficial to improving the overall strength of the first potting part and to controlling the density of the first density zone 31 and the second density zone 32.

[0067] For example, a second transition region 323 is formed at the end of the second density region 32 near the third density region 33, and the density of the second transition region 323 decreases from bottom to top. For example, the density at the bottom of the second transition region 323 is the same as the density of the density stable region 322, and the density at the top of the second transition region 323 is the same as the density at the bottom of the third density region 33, thereby forming a transition between the second density region 32 and the third density region 33.

[0068] In one exemplary embodiment of this disclosure, a first skin layer 41 is provided at the bottom of the first density region 31, and the first skin layer 41 is attached to the bottom wall of the shell 1; the density of the first skin layer 41 is greater than that of the first density region 31. Exemplarily, the thickness of the first skin layer 41 can be relatively thin, for example, less than that of the first density region 31. The foaming speed at the first skin layer 41 is slower, which is beneficial to improving the overall strength of the first potting portion.

[0069] For example, the first filling portion may have a second skin layer 42 on the side adjacent to the top cover 5, and the density of the second skin layer 42 may be equal to that of the first skin layer 41. The thickness of the second skin layer 42 may be thinner, for example, close to the thickness of the first skin layer 41. For example, the ratio of the thickness of the second skin layer 42 to the thickness of the first skin layer 41 is not less than 0.8 and not greater than 1.2.

[0070] It should be noted that, in the embodiments of this disclosure, the thickness of the first transition region 321 and the second transition region 323 can be regarded as belonging to the second density region 32. For example, the "bottom of the second density region 32" mentioned in this disclosure can refer to the bottom of the first transition region 321; the "height range of the second density region 32" can refer to the height range of the first transition region 321, the density stabilization region 322, and the second transition region 323.

[0071] In some exemplary embodiments of this disclosure, the first density region 31 and the second density region 32 of this disclosure can be formed by controlling the process parameters of the foaming of the potting material. In one exemplary embodiment, after the potting material is filled into a specific area inside the housing 1, the potting material is first foamed under a first foaming parameter to form the first density region 31; then the potting material is foamed under a second foaming parameter to form the second density region 32.

[0072] For example, a method for forming an energy storage component provided in this disclosure includes steps S100 to S300.

[0073] Step S100: Install the battery cell 2 into the housing 1; fill at least a portion of the first space and the second space with potting material;

[0074] Step S200: The potting material is foamed under the first foaming parameters to form the first density zone 31;

[0075] Step S300: The potting material is foamed under the second foaming parameters to form the second density zone 32.

[0076] The first and second foaming parameters may include air pressure. Specifically, in steps S200 to S300, the air pressure of the first foaming parameter can be lower than the air pressure of the second foaming parameter. During the foaming process, higher air pressure acts on the upper surface of the potting material, inhibiting the foaming process of the foam and reducing the foaming rate, thus forming a higher density region. Lower air pressure has the opposite effect. By adjusting the air pressure parameters during the potting process, a first density region 31 with relatively low density and a second density region 32 with relatively high density can be formed.

[0077] In one embodiment, the pressure of the first foaming parameter can be negative; for example, the relative pressure of the first foaming parameter is not greater than -20 kPa. Relative pressure is the difference between absolute pressure and atmospheric pressure. For example, with atmospheric pressure as a reference of 101.325 kPa, the absolute pressure of the first foaming parameter is not greater than 81.325 kPa. In the following description of embodiments, for ease of description and understanding by those skilled in the art, unless otherwise specified, the air pressure parameters used in the experiment refer to relative pressure.

[0078] In one embodiment, the air pressure of the first foaming parameter can be -40 kPa. The first density region 31 foams under negative pressure, and its density can be lower than that of the foamed adhesive in its naturally foaming state under normal pressure, thereby achieving increased foaming speed and weight reduction. In one embodiment, the relative air pressure of the first foaming parameter is not less than -40 kPa to avoid the potting material foaming too quickly and becoming difficult to control.

[0079] The pressure of the second foaming parameter can be atmospheric pressure or positive pressure. That is, the relative pressure of the second foaming parameter is not less than 0. For example, the pressure of the second foaming parameter can be atmospheric pressure or a positive pressure not greater than 40 kPa. For example, with atmospheric pressure as a reference of 101.325 kPa, the absolute pressure of the second foaming parameter is not greater than 141.325 kPa.

[0080] In one embodiment, the pressure of the second foaming parameter can be 40 kPa. The second density region 32 foams under positive pressure, and its density can be higher than that of the foam that naturally foams under normal pressure, thereby ensuring that the strength and hardness of the central region in the height direction of the large surface and sides of the battery cell 21 are improved.

[0081] For example, in step S100, after the battery unit 2 is installed into the housing 1, the energy storage component to be potted is sent into the work area or work chamber. Exemplarily, the assembled energy storage component to be potted is transported by an AGV (Automated Guided Vehicle) into the pressure regulating chamber, all doors are closed and sealed, and the AGV is locked. Simultaneously, the pressure regulating chamber's adjustment program runs, and the internal pressure drops and stabilizes at -20 kPa.

[0082] In step S100, potting material is filled into at least one of the first and second gaps. Specifically, the potting robot performs potting at the designated locations according to a set potting program. The amount of potting material can be designed for each area in a fully potted state (potting to form a first potting section, a second potting section, and a third potting section). The potting sequence can be to first pot the first and second spaces, and after an interval of 160 seconds, start potting the top area of ​​the battery unit 2. The potting material has an expansion time of approximately 165-170 seconds under normal temperature and pressure laboratory conditions, and the time from expansion at the bottom of the liquid cooling plate 22 to contact with the top cover 5 is approximately 190-200 seconds. The density of the naturally expanding foam is approximately 0.24 g / cm3, corresponding to a Shore hardness of A45 degrees and a compressive modulus of 60 MPa.

[0083] In step S200, the foaming adhesive expands for 175 seconds at -20 kPa to form the first density zone 31.

[0084] In step S300, the air pressure in the air pressure regulating chamber is continuously increased from negative pressure -20kPa to positive pressure 20kPa at a rate of 40kPa / min. The air pressure regulation is expected to take 60s. The chamber is then maintained at positive pressure of 20kPa for 60s to form a second density zone 32 (including a first transition zone 321 and a density stabilization zone 322).

[0085] After the second density region 32 is formed, the method for forming the energy storage component may further include:

[0086] Step S400: The potting material is foamed under the third foaming parameter to form the third density zone 33, wherein the third foaming parameter includes air pressure, and the air pressure of the third foaming parameter is lower than the air pressure of the second foaming parameter.

[0087] Step S500: Close the top cover 5.

[0088] In step S400, the pressure in the pressure regulating chamber can be reduced to normal or negative pressure within 30 seconds to form the second transition zone 323 and the third density zone 33. For example, the pressure in the pressure regulating chamber can be reduced to negative pressure first to form the second transition zone 323 and part of the third density zone 33; then the pressure in the pressure regulating chamber can be restored to normal pressure. In step S500, after the AGV trolley leaves the chamber and in subsequent processes, the potting material continues to expand to form part of the third density zone 33 and the second skin layer 42. In step S500, after the AGV trolley leaves the chamber, the top cover 5 is fastened within 20 seconds to ensure that the potting material can adhere to the top cover 5 during the expansion process. Alternatively, the top cover 5 can be fastened inside the pressure regulating chamber.

[0089] For example, after the above process, the state of the first filling part is as follows: the first density region 31 occupies 5% to 10% of the height of the first filling part, and the density is 0.18 g / cm³. 3 The corresponding hardness is Shore A 35, and the corresponding compressive modulus is 45 MPa. The second density zone 32 (including the first transition zone 321, the density stabilization zone 322, and the second transition zone 323) occupies 75% to 80% of the height of the first potting section, and the average density within the second density zone 32 is 0.35 g / cm³. 3 The highest density near the 21-sided surface of the battery cell can reach 0.45 g / cm³. 3 The corresponding hardness range is Shore A 40 to Shore D 25, and the corresponding compressive modulus ranges from 70 to 130 MPa. The third density zone 33 occupies 10% to 20% of the height of the first potting section, and its properties are close to those of the free bubbles generated by the potting material under normal temperature and pressure conditions in the laboratory, with a density of approximately 0.24 g / cm³. 3 The hardness corresponding to this density is Shore A 45 degrees, and the corresponding compressive modulus is 60 MPa. For example, a second skin layer 42 is formed on top of the first potting portion, and the foaming process is restricted during the initiation and termination stages, and its density is higher than that of the third density region 33.

[0090] In one embodiment, the potting process can be performed in two stages. The first potting is only used to pot the first space, and the starting height is designed to be flush with the top cover of the battery cell 21, that is, the total starting height of the first potting is the height of the battery cell 21 casing. After the potting material of the first potting is completed, the second potting is performed. The second potting is used to form the second potting part and the third potting part and to pot the second space, that is, the potting area is the top area of ​​the first potting part and the area above the battery cell 2, wherein the amount of potting adhesive used in the area above the battery cell 2 is reserved for the filling amount of the first side gap 201.

[0091] In step S100, the pressure regulating chamber adjustment procedure lowers and stabilizes the internal pressure to -30 kPa. During the first potting process, a rigid potting compound with low reactivity is used. Its foaming time under normal temperature and pressure laboratory conditions is approximately 220–240 s, and the time from the bottom of the liquid cooling plate 22 to the shoulder height of the battery cell 21 is approximately 230–240 s; the density of the foam in its naturally foamed state is approximately 0.26 g / cm³. 3 The hardness corresponding to this density is Shore hardness D25, and the corresponding compressive modulus is 140MPa.

[0092] In step S200, the foam is heated at -30 kPa for 250 s (initiation time 240 s + initiation time 10 s) to form the first density zone 31.

[0093] In step S300, the air pressure in the air pressure regulating chamber is continuously increased from negative pressure -30kPa to positive pressure 30kPa at a rate of 40kPa / min. The air pressure regulation is expected to take 90s, and the positive pressure condition of 30kPa is maintained for 40s.

[0094] In step S400, the air pressure in the air pressure regulating chamber can be reduced to -30kPa in 90s and maintained until the potting compound is fully ignited. Finally, the height of the top of the first potting compound is slightly lower than or equal to the height of the top cover of the battery cell 21, and the height difference between the two ranges from 0 to 3mm.

[0095] Before step S500, the method for forming the energy storage component may further include:

[0096] Step S600: Increase the air pressure in the air pressure regulating chamber and fill the top of the first filling part and the top area of ​​the battery unit 2.

[0097] Specifically, after the first filling section is formed, the air pressure regulation program is run to increase the pressure from -30 kPa to atmospheric pressure at a rate of 40 kPa / min, with an estimated pressure regulation time of 45 seconds. Then, a second filling is performed by a filling robot. The filling material used for the second filling can be the same as that used for the first filling, or, provided that the interfacial bonding strength and compatibility of the two filling materials meet the requirements, a different filling material can be used according to functional needs. After the second filling is completed at atmospheric pressure, in step S500, after the AGV trolley exits the chamber, the upper cover 5 is fastened as soon as possible to ensure that the filling material can adhere to the upper cover 5 during the initiation process.

[0098] For example, after the above process, the first potting portion fills the first space, and the state of the first potting portion is: the first density region 31 occupies 5% to 10% of the height of the cell 21, and the density is 0.19 g / cm³. 3The corresponding hardness is Shore hardness D18, and the corresponding compressive modulus is 110 MPa. The second density region 32 (including the first transition region 321 and the second transition region 323) accounts for 65% to 85% of the height of the cell 21, and the average density within the second density region 32 is 0.4 g / cm³. 3 The highest density near the 21-sided surface of the battery cell can reach 0.52 g / cm³. 3 The corresponding hardness range is Shore hardness D40 to Shore hardness D60, and the corresponding compression modulus range is 160 to 210 MPa. The density and performance of the third density zone 33, formed by two encapsulation processes, are also distributed in two layers: the third density zone 33 formed under negative pressure conditions accounts for 5% to 30% of the cell height 21, and its density and performance indicators are close to those of the first density zone 31. The density and performance parameters of the third density zone 33 formed during the atmospheric pressure initiation process are close to those of free bubbles initiated under laboratory ambient temperature and pressure conditions, with a density of approximately 0.26 g / cm³. 3 The hardness corresponding to this density is Shore hardness D25, and the corresponding compressive modulus is 140MPa.

[0099] For example, the first foaming parameter and the second foaming parameter include temperature. Specifically, in steps S200 to S300, the temperature of the first foaming parameter can be higher than the temperature of the second foaming parameter. During the foaming process, a higher temperature can accelerate the chemical reaction rate of the potting compound, shorten the foaming time, and form a region with lower density. A lower temperature has the opposite effect, inhibiting the chemical reaction rate of the potting compound. By adjusting the temperature parameter during the potting process, a first density region 31 with relatively low density and a second density region 32 with relatively high density can be formed.

[0100] In one embodiment, the temperature of the first foaming parameter can be higher than room temperature, for example, higher than 25°C. When the foam is at the bottom, controlling the temperature of the adhesive and the parts in contact with the adhesive to be higher allows its density to be lower than that of the foam naturally foaming at room temperature, thereby achieving increased foaming speed and weight reduction.

[0101] The temperature of the second foaming parameter can be lower than room temperature, for example, lower than 21°C. After the foaming in the first density zone 31 is completed, that is, when the foaming adhesive has expanded to the middle area of ​​the large surface of the battery cell 21, the temperature of the foaming adhesive and the temperature of the parts in contact with the adhesive are rapidly reduced to form the second density zone 32. Its density can be higher than that of the foaming adhesive in the naturally expanded state at room temperature, thereby ensuring that the strength and hardness of the middle area of ​​the large surface and side of the battery cell 21 in the height direction are improved.

[0102] When the second density zone 32 is close to completion of expansion, for example, when the foam is close to the top area, the temperature of the adhesive can be rapidly increased to form the third density zone 33.

[0103] For example, in step S100, after the battery unit 2 is installed into the housing 1, the energy storage component to be potted is sent into the work room or work chamber. Exemplarily, the assembled energy storage component to be potted is transported into the temperature control chamber by an AGV, and the area to be potted and the components inside the housing 1 are heated by infrared radiation heating or induction heating, for example, to 50-55°C.

[0104] At least one of the first and second spaces is filled with potting material. Specifically, potting can be carried out at a high temperature of 50-55°C, and the outlet temperature of the potting compound is stably maintained between 23-25°C by a temperature control device integrated near the dispensing port of the dispensing robot. The expansion time of the potting compound under normal temperature and pressure laboratory conditions is approximately 165-170 seconds, and the time from expansion from the bottom of the liquid cooling plate 22 to contact with the top cover 5 is approximately 190-200 seconds; the density of the foamed compound in its naturally expanding state is approximately 0.24 g / cm³. 3 The hardness corresponding to this density is Shore A 45 degrees, and the corresponding compressive modulus is 60 MPa.

[0105] In step S200, the foaming adhesive begins to expand after being kept at 50-55°C for 110-120 seconds, forming the first density zone 31.

[0106] After the adhesive has foamed for 10 seconds, in step S300, a cooling process is initiated, for example, by using a rapid cooling medium such as liquid nitrogen or dry ice to lower the temperature inside the temperature control chamber. For instance, the surface temperature of the foaming adhesive and the components in contact with it is reduced to 0–5°C within 40 seconds and maintained within this temperature range for 110–120 seconds, forming a second density region 32 (including a first transition region 321 and a density stabilization region 322). After the second density region 32 is formed, the method for forming the energy storage component may further include:

[0107] Step S400: The potting material is foamed under the third foaming parameter to form the third density zone 33, wherein the third foaming parameter includes temperature, and the temperature of the third foaming parameter is higher than the temperature of the second foaming parameter.

[0108] Step S500: Close the top cover 5.

[0109] In step S400, the temperature of the adhesive and the surface of the parts in contact with it can be raised to 50-55°C in 40 seconds and maintained for 10 seconds to form the second transition zone 323 and the third density zone 33. In step S500, the upper cover 5 can be fastened quickly after the AGV trolley leaves the chamber, or the upper cover 5 can be fastened while the temperature is maintained in the temperature-controlled chamber, which helps to ensure the adhesion of the potting material to the contact position of the upper cover 5.

[0110] For example, after the above process, the state of the first filling part is as follows: the first density region 31 occupies 5% to 10% of the height of the first filling part, and the density is 0.17 g / cm³. 3 The corresponding hardness is Shore A 30, and the corresponding compressive modulus is 40 MPa. The second density zone 32 (including the first transition zone 321, the density stabilization zone 322, and the second transition zone 323) occupies 75% to 80% of the height of the first potting part, and the average density in the second density zone 32 is 0.35 g / cm³. 3 The highest density near the 21-facet area of ​​the battery cell can reach 0.47 g / cm³. 3 The corresponding hardness range is Shore A 35 to Shore D 30, and the corresponding compressive modulus ranges from 55 to 140 MPa. The third density zone 33 occupies 10% to 20% of the height of the first potting section, and its properties are similar to those of the first density zone 31, with a density of approximately 0.18 g / cm³. 3 The hardness corresponding to this density is Shore A 32, and the corresponding compressive modulus is 46 MPa.

[0111] In some embodiments of this disclosure, the first foaming parameter and the second foaming parameter include air pressure and temperature. In steps S200 to S300, both the air pressure parameter and the temperature parameter can be adjusted to form a first density region 31 with a relatively low density and a second density region 32 with a relatively high density, which meet the requirements. Specific adjustment methods can be referred to the description of the foregoing exemplary embodiments, and will not be detailed here.

[0112] Exemplarily, a method for forming a third potting portion according to some exemplary embodiments of the present disclosure includes:

[0113] Step S1000: Fill the space between the top cover 5 and the battery cell 2 with potting material.

[0114] Step S2000: Attach the top cover 5 to the top of the housing 1.

[0115] Step S3000: Evacuate the air from inside the housing 1.

[0116] In step S1000, potting material is filled between the upper cover 5 and the battery cell 2. Specifically, this can be done in step S100, during the process of filling at least a portion of the first space and the second space with potting material. For example, the amount of potting material in step S100 includes the amount used to form the third potting portion. Alternatively, the third potting portion can be formed by a second potting process after the first potting portion or the first and second potting portions have been formed.

[0117] In steps S2000 to S3000, after the top cover 5 is fastened, during the foaming process of the potting material, air is evacuated from the inside of the housing 1, that is, air is evacuated from the cavity. This can improve the foaming rate of the potting material and speed up the production cycle. On the other hand, since the viscosity of the potting material is related to the foaming process time, the reduced foaming time between the top cover 5 and the battery cell 2 can also improve the bonding strength between them.

[0118] Furthermore, since the casing 1 is already fully filled with potting material, when the inside of the casing 1 is evacuated, the negative pressure concentrates in the area from below the top cover 5 to the top of the battery cell 2. For part of the structure of the top cover 5, the top cover 5 can be made slightly concave, with the downward bending of the central area being greater than that of the areas on both sides that are locked to the casing 1. During the initiation process of the potting material, it can first contact the central area of ​​the top cover 5 to achieve adhesion, forming the aforementioned third potting part where the gap between the central area and the top cover 5 is smaller than the gap between the edge area and the top cover 5. On the one hand, this can improve the adhesion strength between the potting material and the central area of ​​the top cover 5; on the other hand, it can also promote and accelerate the process of gas being discharged from the inside of the energy storage component, avoiding the situation where the edge area contacts and adheres to the inside of the top cover 5 first, trapping the remaining gas in the center, resulting in the formation of an island-like trapped gas in the central area, and reducing the effective adhesion area between the potting material and the top cover 5.

[0119] For example, the interior of the housing 1 can be evacuated by the explosion-proof valve 6 of the energy storage component.

[0120] According to another aspect of this disclosure, a vehicle is provided, including any of the aforementioned energy storage components. The energy storage component may be, for example, a vehicle battery pack. In the energy storage component of the vehicle of this disclosure, the entire energy storage component pack and the battery cells 21 have strong resistance to mechanical damage. Simultaneously, because the risk of thermal thinning and carbonization of the potting material in the second density region 32 is reduced due to heat, the risk of thermal runaway due to thermal diffusion is also reduced, which is beneficial to improving vehicle safety. Furthermore, the relatively low density of the first density region 31 helps to save time initiating the potting material to form the first potting portion, improving the production efficiency of the energy storage component and the vehicle, and also helps to reduce the overall amount of potting material used, which is beneficial to weight reduction of the energy storage component and the entire vehicle.

[0121] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. An energy storage component, characterized in that, include: Shell (1); A battery unit (2) is disposed in the housing (1). The battery unit (2) includes a plurality of cells (21) arranged in an array. A first space is formed between the battery unit (2) and the side wall of the housing (1), and a second space is formed between the cells (21). The first potting portion fills at least a portion of the first space and the second space; the first potting portion includes a first density region (31) and a second density region (32) sequentially from the bottom to the top of the housing (1), the second density region (32) corresponds at least to the middle part of the height direction of the cell (21), and the density of the second density region (32) is higher than that of the first density region (31).

2. The energy storage component according to claim 1, characterized in that, The density of the first density region (31) is 0.16–0.28 g / cm³. 3 ; and / or, the density of the second density region (32) is 0.28–0.55 g / cm³. 3 .

3. The energy storage component according to claim 1, characterized in that, The ratio of the thickness D2 of the second density region (32) to the thickness H of the first potting part satisfies 0.65≤D2 / H≤0.85; and / or, the ratio of the distance H1 from the bottom of the second density region (32) to the bottom of the first potting part to the thickness H of the first potting part satisfies 0.05≤H1 / H≤0.

15.

4. The energy storage component according to claim 1, characterized in that, The second density region (32) forms a first transition region (321) near the end of the first density region (31); the density of the first transition region (321) increases from the bottom to the top.

5. The energy storage component according to claim 1, characterized in that, The bottom of the first density region (31) is provided with a first skin layer (41), which is attached to the bottom wall of the shell (1); the density of the first skin layer (41) is greater than that of the first density region (31).

6. The energy storage component according to claim 1, characterized in that, A third density region (33) is provided at the top of the second density region (32), and the density of the third density region (33) is less than that of the second density region (32).

7. The energy storage component according to any one of claims 1 to 6, characterized in that, The battery cell (2) and the four sides of the housing (1) respectively form a front cavity (101), a first side cavity (102), a rear cavity (103) and a second side cavity (104); the first potting portion fills at least one of the front cavity (101), the first side cavity (102), the rear cavity (103) and the second side cavity (104).

8. The energy storage component according to any one of claims 1 to 6, characterized in that, The battery cells (21) are arranged in an array along a first direction and a second direction. A first side gap (201) is formed between the battery cells (21) arranged along the first direction. The first potting portion fills at least one of the first side gaps (201). And / or, a second side gap (202) is formed between the battery cells (21) arranged along the second direction. The first potting portion fills at least one of the second side gaps (202).

9. The energy storage component according to claim 1, characterized in that, The energy storage component includes an integrated busbar (23) and a second potting section. The integrated busbar (23) is located on the top of the battery cell (2) and is connected to the battery cell (21). The second potting section at least fills the area between the top of the battery cell (21) and the integrated busbar (23).

10. The energy storage component according to claim 9, characterized in that, The first potting portion and the second potting portion are formed by foaming and potting with the same potting material.

11. The energy storage component according to claim 1, characterized in that, The energy storage component includes a top cover (5) and a third potting portion; the top cover (5) is fastened to the top of the housing (1), and the third potting portion fills at least between the top of the battery cell (2) and the top cover (5).

12. The energy storage component according to claim 11, characterized in that, The third potting section has a central area and an edge area located around the central area. The gap between the central area and the top cover (5) is not greater than the gap between the edge area and the top cover (5).

13. The energy storage component according to claim 12, characterized in that, From the center to the edge of the top cover (5), the distance between the top of the third potting portion and the bottom of the top cover (5) gradually increases.

14. A vehicle, characterized in that, It includes the energy storage component as described in any one of claims 1 to 13.

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