Battery pack and electric device

Abstract

A battery pack and an electric device. The battery pack comprises a case and a plurality of battery cells (1) arranged in the case, the case comprises a cover and a bottom plate (2), an explosion-proof valve is arranged on the case, and the battery cells (1) each comprise a pressure relief area (1.1); the case further comprises an adhesive (3), and the adhesive (3) covers the pressure relief area (1.1); and the adhesive (3) comprises a foaming adhesive (3.1) and a non-foaming adhesive (3.2), and the portion of the adhesive (3) close to the cover is the non-foaming adhesive (3.2). The foaming adhesive (3.1) can adhere and fix elements such as the battery cells (1) together, and the mass of the foaming adhesive (3.1) is light, so that the weight of the battery pack can be reduced. However, the foaming adhesive (3.1) is disordered during foaming, rendering the surface uneven; the portion of the adhesive (3) close to the cover is set to be the non-foaming adhesive (3.2), so that the surface of the adhesive (3) can be smooth, so as to ensure that the pressure relief area (1.1) is completely covered, thereby allowing a thermal runaway gas to be directionally discharged; and even if the thermal runaway gas is discharged to the bottom of the battery pack, the safety of a cockpit can be avoided.

Description

Battery packs and power devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application CN202311765704.3, filed on December 20, 2023, with the invention name “Battery Pack and Electrical Device”. The entire contents of the above Chinese patent application are incorporated into this application by reference. Technical Field

[0003] The present invention relates to the field of electrical equipment, and specifically provides a battery pack and an electrical device. Background Art

[0004] As energy storage devices, battery packs are widely used in various electrical devices, such as mobile phones, laptops, drones, and electric vehicles. This has driven the development of related industries, and many companies have invested in battery research and development.

[0005] Battery safety is one of the most pressing concerns in the industry. Battery packs are typically equipped with explosion-proof valves. If a battery cell in the pack experiences thermal runaway, the resulting gases are discharged through the valves. However, in practice, thermal runaway fires in battery packs often spread to the cockpit.

[0006] Summary of the Invention

[0007] In response to safety issues of battery packs, the present invention provides a battery pack, which includes a box body and multiple battery cells arranged in the box body, the box body includes a box cover and a bottom plate, the box body is provided with an explosion-proof valve, and the battery cells include a pressure relief area; the box body also includes an adhesive, and the adhesive covers the pressure relief area; the adhesive includes foam and non-foam, and the portion of the adhesive close to the box cover is non-foam.

[0008] Foam glue can bond battery cells and other components together, and its light weight can reduce the weight of the battery pack. However, foam glue is disordered during expansion, resulting in an uneven surface. Using a non-foamed adhesive layer near the lid can smooth the adhesive surface, ensuring complete coverage of the pressure relief zone and directional discharge of thermal runaway gases, even if they are released toward the bottom of the battery pack, to avoid endangering the safety of the cockpit.

[0009] In an optional technical solution of the present invention, the pressure relief zone faces the box cover, the foam is arranged in the gaps between the plurality of battery cells, and the non-foam covers the pressure relief zone.

[0010] In an optional technical solution of the present invention, the direction from the bottom plate to the cover is a first direction, gaps extending along the first direction are defined between adjacent battery cells, the pressure relief zone faces the gaps, and the foamed adhesive and the non-foamed adhesive are disposed within the gaps. In this manner, the foamed adhesive and the non-foamed adhesive can both fill the gaps, thereby integrating the battery cells, and allow thermal runaway gases released from the pressure relief zone to be discharged downward in a directed manner.

[0011] In an optional technical solution of the present invention, the battery cell is a soft-pack battery cell, comprising a casing and a battery cell disposed within the casing. The casing includes a sealed edge facing the gap, and the tabs of the battery cell extend from the sealed edge. When thermal runaway occurs in the soft-pack battery cell, the thermal runaway gas will break through the sealed edge and be released.

[0012] In an optional technical solution of the present invention, along the first direction, the adhesive includes a section of foam glue and a section of non-foam glue, and the height H1 of the foam glue and the height H2 of the non-foam glue satisfy: 2.5:1≤H1 / H2≤4:1. If the height ratio of the foam glue to the non-foam glue is too small, the battery pack will be too heavy. If the height ratio of the foam glue to the non-foam glue is too large, the non-foam glue will not be able to cover the surface of the foam glue, resulting in the adhesive not being able to completely cover the pressure relief area of ​​the battery cell and not being able to promote directional exhaust. Setting the height ratio of the foam glue to the non-foam glue within the above numerical range ensures directional exhaust of thermal runaway while making the battery pack have a smaller weight.

[0013] In an optional technical solution of the present invention, along the first direction, the adhesive includes at least two sections of the foamed adhesive or at least two sections of the non-foamed adhesive, and the foamed adhesive and the non-foamed adhesive are arranged at intervals.

[0014] In an optional technical solution of the present invention, along the first direction, the adhesive extends beyond the edge seal by a dimension L that satisfies the following conditions: 0.5 mm ≤ L ≤ 2 mm. Setting the adhesive's extension beyond the edge seal within this numerical range ensures directional venting of thermal runaway while reducing the battery pack's weight.

[0015] In an optional technical solution of the present invention, the material of the foamed rubber is or the material of the non-foamed rubber includes polyurethane.

[0016] In an optional technical solution of the present invention, a first channel is provided on the bottom plate, and the housing further includes a sidewall, wherein a second channel connected to the explosion-proof valve is provided on the sidewall, and the first channel and the second channel are in communication. Thermal runaway gas is directed downwardly discharged into the first channel, then passes through the second channel in the housing, and finally discharged out of the housing through the explosion-proof valve.

[0017] The present invention also provides an electrical device comprising the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the arrangement of battery cells in a box;

[0019] Figure 2 is a schematic diagram of setting adhesive in the gap between battery cells;

[0020] FIG3 is a partial enlarged view of FIG2;

[0021] The reference numerals are as follows

[0022] Battery cell 1;

[0023] Pressure relief area 1.1;

[0024] Bottom plate 2, first channel 2.1;

[0025] Adhesive 3, foaming adhesive 3.1, non-foaming adhesive 3.2;

[0026] Gap 4;

[0027] Foam 5;

[0028] Second channel 6. DETAILED DESCRIPTION

[0029] The following describes optional embodiments of the present invention with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "distance", "width", "thickness", "up", "down", "left", "right", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the description of the present invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly specifying the quantity of the technical features indicated. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] As shown in Figures 1 and 2, the present invention provides a battery pack comprising a housing (not shown) and a plurality of battery cells 1 disposed therein. The housing comprises a lid (not shown) and a bottom plate 2, and is provided with an explosion-proof valve (not shown). The battery cells 1 include a pressure relief area 1.1. The housing also includes an adhesive 3 covering the pressure relief area 1.1. The adhesive comprises a foamed adhesive 3.1 and a non-foamed adhesive 3.2, with the portion of the adhesive near the lid being non-foamed adhesive. The foamed adhesive 3.1 can bond and secure components such as the battery cells 1 together, and its light weight can reduce the weight of the battery pack. However, the foaming glue 3.1 is disordered during foaming, resulting in an uneven foaming surface. Setting the adhesive portion near the box cover to non-foaming glue 3.2 can make the adhesive surface smooth. This can ensure that the pressure relief area 1.1 is fully covered, thereby allowing the thermal runaway gas to be discharged in a targeted manner, even if the thermal runaway gas is discharged to the bottom of the battery pack, thus avoiding endangering the safety of the cockpit.

[0034] In an optional embodiment of the present invention, the pressure relief area of ​​the battery cells 1 faces the case lid, the foamed adhesive is placed in the gaps between the multiple battery cells, and the non-foamed adhesive covers the pressure relief area. In this embodiment, the battery cells 1 can be square or cylindrical, and the pressure relief area can be an explosion-proof valve. Of course, the battery cells 1 can also be soft packs, and the pressure relief area can be a sealed edge. The non-foamed adhesive can be placed only on the top of the battery cells 1 to cover the pressure relief area, or it can fill the gaps between the battery cells and cover the pressure relief area.

[0035] In an optional embodiment of the present invention, as shown in Figure 2, the direction from the bottom plate to the cover is a first direction. A gap 4 extending along the first direction is defined between adjacent battery cells. The pressure relief area 1.1 of the battery cell 1 faces this gap 4. The foamed plastic 3.1 and the non-foamed plastic 3.2 are disposed within this gap 4. In this embodiment, the battery cell 1 may be a prismatic battery cell, and the pressure relief area may be an explosion-proof valve on the prismatic case. That is, the explosion-proof valve faces this gap 4. The explosion-proof valve may be covered by either the non-foamed plastic 3.2 or the foamed plastic 3.1.

[0036] The battery cell can also be a soft-pack battery cell, which includes a packaging shell and a battery cell arranged in the packaging shell. The packaging shell is a three-layer aluminum-plastic film composed of PP (Polypropylene), aluminum layer and nylon. After the battery cell and electrolyte are placed in the packaging shell, the PP layer is hot-melted to form an edge seal to achieve a sealing effect. The tabs extend from the edge seal to the outside of the packaging shell for electrical connection. When a soft-pack battery cell experiences thermal runaway, it will break through the edge seal and release pressure, so the edge seal is the pressure relief zone 1.1. The tabs of adjacent soft-pack battery cells are connected in series and parallel in the gap 4. The foamed glue 3.1 and non-foamed glue 3.2 fill the gap 4 and cover the edge seal of the soft-pack battery cell, so that multiple soft-pack battery cells and other components are bonded into a whole while avoiding excessive weight and achieving directional downward discharge of thermal runaway gas.

[0037] In an optional embodiment of the present invention, as shown in Figures 2 and 3, along the first direction, the adhesive 3 includes a section of foam glue 3.1 located at the bottom and a section of non-foam glue 3.2 disposed on the foam glue 3.1. The ratio of the height H1 of the foam glue 3.1 to the height H2 of the non-foam glue 3.2 satisfies the following conditions: 2.5:1≤H1 / H2≤4:1. If the height ratio of the foam glue 3.1 and the non-foam glue 3.2 is too small, the battery pack will be too heavy. If the height ratio of the foam glue 3.1 and the non-foam glue 3.2 is too large, the non-foam glue 3.2 will not cover the surface of the foam glue, resulting in the adhesive not being able to completely cover the pressure relief area of ​​the battery cell and not being able to promote directional venting. Setting the height ratio of the foam glue 3.1 and the non-foam glue 3.2 within the above-mentioned numerical range ensures directional venting of thermal runaway while making the battery pack lighter. Specifically, the value of H1 / H2 can be 2.5:1, 2.8:1, 3:1, 3.1:1, 3.5:1, or 4:1.

[0038] In an alternative embodiment of the present invention, the adhesive 3 may also include at least two sections of foamed adhesive or at least two sections of non-foamed adhesive along the first direction, with the foamed adhesive and the non-foamed adhesive arranged alternately. For example, along the first direction, the adhesive may have a stacked structure of foamed adhesive-non-foamed adhesive-foamed adhesive-non-foamed adhesive, or a stacked structure of non-foamed adhesive-foamed adhesive-non-foamed adhesive.

[0039] In an optional embodiment of the present invention, along the first direction, the dimension L of the adhesive 3 extending beyond the edge seal (pressure relief zone 1.1) satisfies the following: 0.5mm≤L≤2mm. Setting the dimension of the adhesive 3 extending beyond the edge seal (pressure relief zone 1.1) within the aforementioned numerical range can ensure directional venting of thermal runaway while reducing the weight of the battery pack. Specifically, L can be 0.5mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, or 2mm.

[0040] In an optional embodiment of the present invention, the material of the foaming rubber and the material of the non-foaming rubber may be a polyurethane system.

[0041] In an optional embodiment of the present invention, as shown in FIG3 , the non-foamed rubber is filled with foam 5 . Since the mass density of the foam is smaller than that of the non-foamed rubber, the weight can be further reduced.

[0042] In an optional embodiment of the present invention, as shown in Figure 1, a plurality of battery cells 1 are arranged in M ​​rows and N columns in the second direction and the third direction in the box, and the plurality of battery cells 1 are connected in series and parallel. Along the third direction, there is a gap 4 between adjacent battery cells, and a foam glue 3.1 is provided in the gap 4. The foam glue 3.1 is used to bond adjacent battery cells and other components to improve the overall strength. In this embodiment, the battery pack also includes a thermal management component (not shown), which is provided between two adjacent battery cells 1 arranged along the second direction and bonded to the battery cells 1. The thermal management component extends along the third direction, and the thermal management component can be formed by splicing a plurality of cold plates along the third direction. The top ends of the plurality of battery cells 1 along the first direction are covered with structural adhesive, which can bond the top ends of the battery cells into one.

[0043] In an optional embodiment of the present invention, a first channel 2.1 is provided on the bottom plate 2. The box further includes a sidewall provided with a second channel 6 connected to the explosion-proof valve. The first channel 2.1 is connected to the second channel 6. The thermal runaway gas is discharged downwardly into the first channel 2.1, then passes through the second channel 6 in the box, and finally discharged out of the box through the explosion-proof valve.

[0044] The present invention also provides an electrical device, comprising a battery pack according to an optional embodiment. The battery pack ensures the electrical device is lightweight while ensuring safety. The electrical device may include, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, a power tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, or the like. Electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft.

[0045] Thus far, the technical solutions of the present invention have been described in conjunction with the optional embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A battery pack, comprising a box and a plurality of battery cells arranged in the box, The box body includes a box cover and a bottom plate, an explosion-proof valve is provided on the box body, and the battery cell includes a pressure relief area; The box body also includes an adhesive, and the adhesive covers the pressure relief area; The adhesive includes foam glue and non-foam glue, the foam glue is foam glue, the non-foam glue is non-foam glue, and the part of the adhesive close to the box cover is non-foam glue.

2. The battery pack according to claim 1, characterized in that: The pressure relief zone faces the box cover, the foam glue is arranged in the gaps between the plurality of battery cells, and the non-foam glue covers the pressure relief zone.

3. The battery pack according to claim 1, wherein: The direction from the bottom plate to the box cover is a first direction, gaps extending along the first direction are arranged between adjacent battery cells, the pressure relief area faces the gaps, and the foaming glue and the non-foaming glue are arranged in the gaps.

4. The battery pack according to claim 3, characterized in that: The battery cell is a soft-pack battery cell, which includes a packaging shell and a battery cell arranged in the packaging shell. The packaging shell includes a sealing edge facing the gap, and the tabs of the battery cell extend from the sealing edge.

5. The battery pack according to claim 4, characterized in that: Along the first direction, the adhesive includes a section of foamed adhesive and a section of non-foamed adhesive, and a height H1 of the foamed adhesive and a height H2 of the non-foamed adhesive satisfy: 2.5:1≤H1 / H2≤4:

1.

6. The battery pack according to claim 4, characterized in that: Along the first direction, the adhesive includes at least two sections of the foamed adhesive or at least two sections of the non-foamed adhesive, and the foamed adhesive and the non-foamed adhesive are arranged at intervals.

7. The battery pack according to claim 4, characterized in that: Along the first direction, a dimension L of the adhesive beyond the edge sealing satisfies: 0.5 mm ≤ L ≤ 2 mm.

8. The battery pack according to claim 1, wherein: The foam material or the non-foam material includes polyurethane.

9. The battery pack according to claim 1, characterized in that: The non-foamed rubber is filled with foam, and the mass density of the foam is smaller than that of the non-foamed rubber.

10. The battery pack according to claim 1, wherein: The bottom plate is provided with a first channel, the box body further comprises a side wall, the side wall is provided with a second channel connected to the explosion-proof valve, and the first channel is communicated with the second channel.

11. An electrical device comprising the battery pack according to any one of claims 1 to 10.

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