Battery pack and electric device

Abstract

A battery pack comprises a box body and a plurality of single batteries arranged in the box body, the box body comprises a box cover and a bottom plate, an anti-explosion valve is arranged on the box body, and each single battery comprises a pressure relief area; an adhesive is further arranged in the box body and covers the pressure relief area; the adhesive comprises polystyrene foam and non-polystyrene foam, and the part, close to the box cover, of the adhesive is non-polystyrene foam. And the polystyrene foam can be used for bonding and fixing elements such as the battery monomers and the like, and the polystyrene foam is light in weight, so that the weight of the battery pack can be reduced. However, the polystyrene foam is disordered during foaming, so that the surface is uneven, and the part, close to the box cover, of the adhesive is non-polystyrene foam, so that the surface of the adhesive can be flat, a pressure relief area can be completely covered, thermal runaway gas can be directionally discharged, and even if the thermal runaway gas is discharged to the bottom of the battery pack, the thermal runaway gas can be discharged to the bottom of the battery pack. Therefore, the safety of the cockpit can be prevented from being harmed.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment, and specifically provides a battery pack and an electrical device. Background Art

[0002] As an energy storage device, the battery pack is widely applied to various electrical devices, such as mobile phones, laptops, drones, and electric vehicles, etc., driving the industrial development of related fields, and many enterprises have invested in battery research and development.

[0003] The safety of the battery is one of the most concerned issues in the field. Usually, an explosion-proof valve is provided on the box body of the battery pack. When a certain battery cell in the battery pack undergoes thermal runaway, the thermal runaway gas will be discharged out of the box through the explosion-proof valve. However, in actual situations, the problem that the thermal runaway of the battery pack catches fire and spreads to the cockpit often occurs. Summary of the Invention

[0004] Aiming at the safety problem of the battery pack, the present invention provides a battery pack, which includes a box body and a plurality of battery cells arranged in the box body. The box body includes a box cover and a bottom plate. An explosion-proof valve is provided on the box body. The battery cell includes a pressure relief area. An adhesive is further included in the box body, and the adhesive covers the pressure relief area. The adhesive includes foaming glue and non-foaming glue, and the part of the adhesive close to the box cover is non-foaming glue.

[0005] The foaming glue can bond and fix components such as battery cells together, and the light weight of the foaming glue can reduce the weight of the battery pack. However, the foaming of the foaming glue is disordered, so the surface will be uneven. By setting the part of the adhesive close to the box cover as non-foaming glue, the surface of the adhesive can be made flat, which can ensure complete coverage of the pressure relief area and enable the thermal runaway gas to be discharged in a specific direction. Even if the thermal runaway gas is discharged towards the bottom of the battery pack, this can avoid endangering the safety of the cockpit.

[0006] In an alternative technical solution of the present invention, the pressure relief area faces the box cover, the foaming glue is arranged in the gaps between the plurality of battery cells, and the non-foaming glue covers the pressure relief area.

[0007] In an alternative technical solution of the present invention, the direction from the bottom plate to the box cover is the first direction. A gap extending in the first direction is provided between adjacent ones of the plurality of battery cells. The pressure relief area faces the gap, and the foaming glue and the non-foaming glue are arranged in the gap. In this way, the foaming glue and the non-foaming glue can not only fill the gap to make the plurality of battery cells a whole, but also enable the thermal runaway gas released from the pressure relief area to be discharged downward in a specific direction.

[0008] In an alternative technical solution of the present invention, the battery cell is a soft-pack battery cell. The soft-pack battery cell includes a packaging shell and an electrode assembly disposed within the packaging shell. The packaging shell includes a sealing edge facing the gap, and the tabs of the electrode assembly extend out from the sealing edge. When the soft-pack battery cell undergoes thermal runaway, the hot gas will break through the sealing edge and be released.

[0009] In an alternative technical solution of the present invention, along the first direction, the adhesive includes a section of foamed adhesive and a section of non-foamed adhesive, and the height H1 of the foamed adhesive and the height H2 of the non-foamed adhesive satisfy:

[0010] 2.5:1 ≤ H1 / H2 ≤ 4:1. If the height ratio of the foamed adhesive to the non-foamed adhesive is too small, the weight of the battery pack will be too large. If the height ratio of the foamed adhesive to the non-foamed adhesive is too large, the non-foamed adhesive will not be able to cover the surface of the foamed adhesive, resulting in the adhesive not being able to completely cover the pressure relief area of the battery cell and thus not being able to promote directional exhaust. By setting the height ratio of the foamed adhesive to the non-foamed adhesive within the above numerical range, while ensuring directional exhaust during thermal runaway, the battery pack has a smaller weight.

[0011] In an alternative 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.

[0012] In an alternative technical solution of the present invention, along the first direction, the dimension L of the adhesive extending beyond the sealing edge satisfies: 0.5 mm ≤ L ≤ 2 mm. By setting the dimension of the adhesive extending beyond the sealing edge within the above numerical range, it is possible to ensure directional exhaust during thermal runaway while making the battery pack have a smaller weight.

[0013] In an alternative technical solution of the present invention, the material of the foamed adhesive or the material of the non-foamed adhesive includes polyurethane.

[0014] In an alternative technical solution of the present invention, a first channel is provided on the bottom plate, and the box body further includes side walls. A second channel connected to the explosion-proof valve is provided on the side walls, and the first channel and the second channel are in communication. The hot gas during thermal runaway is discharged downward to the first channel, then passes through the second channel on the box body, and finally is discharged out of the box through the explosion-proof valve.

[0015] The present invention also provides an electrical device including the above battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the arrangement of battery cells within the box body;

[0017] Figure 2 It is a schematic diagram of the adhesive provided at the gap of the battery cell;

[0018] Figure 3 is Figure 2 a partially enlarged view of;

[0019] The reference numerals are as follows

[0020] Battery cell 1;

[0021] Pressure relief area 1.1;

[0022] Bottom plate 2, first channel 2.1;

[0023] Adhesive 3, foaming adhesive 3.1, non-foaming adhesive 3.2;

[0024] Gap 4;

[0025] Foam 5;

[0026] Second channel 6. Detailed implementation manners

[0027] The optional implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "distance", "width", "thickness", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is 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 should not be construed as a limitation of the present invention.

[0029] In the description of the present invention, the terms "first", "second", "third", "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0030] In addition, it should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "arranged", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] As Figure 1 and Figure 2As shown, the present invention provides a battery pack, which includes a box body (not shown) and a plurality of battery cells 1 disposed in the box body. The box body includes a box cover (not shown) and a bottom plate 2, and an explosion-proof valve (not shown) is provided on the box body. The battery cell 1 includes a pressure relief area 1.1; an adhesive 3 is further included in the box body, and the adhesive covers the pressure relief area 1.1; the adhesive includes a foaming adhesive 3.1 and a non-foaming adhesive 3.2, and the part of the adhesive close to the box cover is the non-foaming adhesive. The foaming adhesive 3.1 can bond and fix components such as the battery cell 1 together, and the light weight of the foaming adhesive 3.1 can reduce the weight of the battery pack. However, the foaming of the foaming adhesive 3.1 is disordered, so the surface foaming is uneven. By setting the part of the adhesive close to the box cover as the non-foaming adhesive 3.2, the surface of the adhesive can be made flat, which can ensure complete coverage of the pressure relief area 1.1 so that the thermal runaway gas is discharged in a directional manner, that is, the thermal runaway gas is discharged towards the bottom of the battery pack, thus avoiding endangering the safety of the cockpit.

[0032] In an alternative embodiment of the present invention, the pressure relief area of the battery cell 1 faces the box cover, the foaming adhesive is disposed in the gap between the plurality of battery cells, and the non-foaming adhesive covers the pressure relief area. In this embodiment, the battery cell 1 can be a square shell or a cylinder, and the pressure relief area can be an explosion-proof valve. Of course, the battery cell 1 can also be a soft package, and the pressure relief area can be a sealing edge. The non-foaming adhesive can be disposed only on the top of the battery cell 1 to cover the pressure relief area, or can both fill the gap between the battery cells and cover the pressure relief area.

[0033] In an alternative embodiment of the present invention, as Figure 2 shown, the direction from the bottom plate to the box cover is the first direction, a gap 4 extending in the first direction is provided between adjacent battery cells, and the pressure relief area 1.1 of the battery cell 1 faces the gap 4. The foaming adhesive 3.1 and the non-foaming adhesive 3.2 are disposed in the gap 4. In this embodiment, the battery cell 1 can be a square shell battery cell, and the pressure relief area can be an explosion-proof valve on the square shell, that is, the explosion-proof valve faces the gap 4. It can be the non-foaming adhesive 3.2 that covers the explosion-proof valve, or it can be the foaming adhesive 3.1 that covers the explosion-proof valve.

[0034] The battery cell can also be a pouch battery cell, which includes a packaging case and an electrode assembly disposed within the packaging case. The packaging case is formed by punching a three-layer aluminum-plastic film composed of PP (Polypropylene), an aluminum layer, and nylon. After placing the electrode assembly and electrolyte, etc. in the packaging case, the PP layer is heat-melted to form a sealing edge, which serves as a sealing function. The tab extends out of the packaging case from the sealing edge for electrical connection. When the pouch battery cell undergoes thermal runaway, it will break through the sealing edge to relieve pressure, so the sealing edge is the pressure relief area 1.1. The tabs of adjacent pouch battery cells are connected in series and parallel in the gap 4. The foamed adhesive 3.1 and the non-foamed adhesive 3.2 are filled in the gap 4 and cover the sealing edge of the pouch battery cell, bonding multiple pouch battery cells and other components into a whole while avoiding excessive weight and realizing the directional downward discharge of thermal runaway gas.

[0035] In an alternative embodiment of the present invention, as Figure 2 and Figure 3 shown, along the first direction, the adhesive 3 includes a section of foamed adhesive 3.1 at the bottom and a section of non-foamed adhesive 3.2 disposed on the foamed adhesive 3.1. The ratio of the height H1 of the foamed adhesive 3.1 to the height H2 of the non-foamed adhesive 3.2 satisfies: 2.5:1 ≤ H1 / H2 ≤ 4:1. If the height ratio of the foamed adhesive 3.1 to the non-foamed adhesive 3.2 is too small, the weight of the battery pack will be too large. If the height ratio of the foamed adhesive 3.1 to the non-foamed adhesive 3.2 is too large, the non-foamed adhesive 3.2 will not cover the surface of the foamed adhesive, resulting in the adhesive not being able to completely cover the pressure relief area of the battery cell and unable to promote directional exhaust. Setting the height ratio of the foamed adhesive 3.1 to the non-foamed adhesive 3.2 within the above numerical range enables the battery pack to have a smaller weight while ensuring directional exhaust during thermal runaway. Specifically, the value of H1 / H2 can be 2.5:1, 2.8:1, 3:1, 3.1:1, 3.5:1, 4:1.

[0036] In an alternative embodiment of the present invention, along the first direction, the adhesive 3 can also include at least two sections of foamed adhesive or at least two sections of non-foamed adhesive, with the foamed adhesive and the non-foamed adhesive arranged at intervals. For example, along the first direction, it can be a laminated structure of foamed adhesive - non-foamed adhesive - foamed adhesive - non-foamed adhesive, or a laminated structure of non-foamed adhesive - foamed adhesive - non-foamed adhesive.

[0037] In an alternative embodiment of the present invention, along the first direction, the dimension L of the adhesive 3 exceeding the sealing edge (pressure relief area 1.1) satisfies: 0.5 mm ≤ L ≤ 2 mm. Setting the dimension of the adhesive 3 exceeding the sealing edge (pressure relief area 1.1) within the above numerical range can ensure directional exhaust during thermal runaway while enabling the battery pack to have a smaller weight. Specifically, L can be 0.5 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm.

[0038] In an alternative embodiment of the present invention, the material of the foaming adhesive and the non-foaming adhesive may be a polyurethane system.

[0039] In an alternative embodiment of the present invention, as Figure 3 shown, the non-foaming adhesive is filled with foam 5. Since the mass density of the foam is smaller than that of the non-foaming adhesive, the weight can be further reduced.

[0040] In an alternative embodiment of the present invention, as Figure 1 shown, a plurality of battery cells 1 are arranged in M rows and N columns in the second direction and the third direction within the box body, 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 foaming adhesive 3.1 is provided in the gap 4. By bonding adjacent battery cells and other components with the foaming adhesive 3.1, the overall strength is improved. In this embodiment, the battery pack further includes a thermal management component (not shown), which is disposed 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 can be formed by splicing a plurality of cold plates along the third direction. The top ends of the plurality of battery cells 1 in the first direction are covered with structural adhesive, which can bond the top ends of the battery cells together.

[0041] In an alternative embodiment of the present invention, a first channel 2.1 is provided on the bottom plate 2, and the box body further includes side walls. A second channel 6 connected to the explosion-proof valve is provided on the side walls, and the first channel 2.1 and the second channel 6 are in communication. The thermal runaway gas is discharged downward to the first channel 2.1, then passes through the second channel 6 on the box body, and finally is discharged out of the box through the explosion-proof valve.

[0042] The present invention also provides an electrical device. The electrical device of the present invention includes the battery pack of the alternative embodiment. By providing the battery pack, the electrical device can be made light in weight while ensuring safety. The electrical device can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, etc. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0043] So far, the technical solutions of the present invention have been described in conjunction with the alternative embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A battery pack, comprising a box body and a plurality of battery cells disposed in the box body, the box body including a box cover and a bottom plate, an explosion-proof valve being provided on the box body, and the battery cell including a pressure relief area; The box body further includes an adhesive covering the pressure relief area; The adhesive includes a foaming adhesive and a non-foaming adhesive, the foaming adhesive being a foaming adhesive, the non-foaming adhesive being a non-foaming adhesive, and the part of the adhesive close to the box cover being a non-foaming adhesive.

2. The battery pack according to claim 1, wherein, The pressure relief area faces the lid, the foaming adhesive is disposed in the gaps between multiple battery cells, and the non-foaming adhesive covers the pressure relief area.

3. The battery pack according to claim 1, wherein, The direction from the bottom plate to the lid is the first direction. There are gaps extending along the first direction between adjacent ones of the multiple battery cells. The pressure relief area faces the gaps, and the foaming adhesive and the non-foaming adhesive are disposed in the gaps.

4. The battery pack according to claim 3, wherein, The battery cell is a soft-pack battery cell, which includes a packaging case and an electrode core disposed in the packaging case. The packaging case includes a sealing edge facing the gap, and the tabs of the electrode core extend out from the sealing edge.

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

1.

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

7. The battery pack according to claim 4, wherein, Along the first direction, the dimension L by which the adhesive extends beyond the sealing edge satisfies: 0.5 mm ≤ L ≤ 2 mm.

8. The battery pack according to claim 1, wherein, The material of the foaming adhesive or the material of the non-foaming adhesive includes polyurethane.

9. The battery pack according to claim 1, wherein, The non-foaming adhesive is filled with foam, and the mass density of the foam is less than that of the non-foaming adhesive.

10. The battery pack according to claim 1, wherein, A first channel is provided on the bottom plate. The box body further includes a side wall, and a second channel connected to the explosion-proof valve is provided on the side wall. The first channel and the second channel are in communication.

11. An electric device, comprising the battery pack according to any one of claims 1 to 9.

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