Battery pack and electric device

Abstract

The invention provides a battery pack which comprises a box body, single batteries and a heat insulation pad, and the box body comprises a bottom plate and a supporting piece arranged on the bottom plate; the battery monomers are arranged in the box body, the end parts of the battery monomers are arranged on the supporting pieces, and a first main body part of each battery monomer comprises a first side wall facing the bottom plate; the heat insulation pad is arranged on the first side wall, a first channel is arranged between the heat insulation pad and the bottom plate, and the heat conductivity coefficient of the heat insulation pad is smaller than 0.1 W / (m.K). The heat insulation pad is arranged on the first side wall of the battery monomer, and the heat conductivity coefficient of the heat insulation pad is less than 0.1 W / (m.K), so that when a certain battery monomer is subjected to thermal runaway, thermal runaway high-temperature gas enters the first channel, and when the thermal runaway high-temperature gas flows in the first channel and is in contact with the adjacent battery monomer, the thermal runaway high-temperature gas is blocked by the heat insulation pad to transfer heat; therefore, the temperature of the adjacent single battery does not rise sharply to cause thermal runaway, so that the thermal runaway is prevented from spreading.

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] New energy vehicles have developed rapidly in recent years due to their environmental protection and low energy consumption. Many car companies have joined the research and development of new energy vehicles. As the most important component of new energy vehicles, the quality of batteries seriously affects the development of new energy vehicles, especially safety issues. We often see reports of new energy vehicles catching fire spontaneously, which can endanger life safety and cause major fires in serious cases.

[0003] In the field, exhaust channels are usually set up in the battery pack to allow the high-temperature gas caused by thermal runaway to be discharged out of the pack. However, the problem of controlled heat spread still exists, causing the entire battery pack to spontaneously combust. Summary of the invention

[0004] In order to solve the problem of thermal runaway propagation in the prior art, the present invention provides a battery pack, comprising: a box body, a battery cell and a thermal insulation pad, the box body comprising a bottom plate and a support member arranged on the above bottom plate; the battery cell is arranged in the above box body, the end of the above battery cell is arranged on the above support member, and the first main body of the above battery cell comprises a first side wall facing the above bottom plate; the thermal insulation pad is arranged on the above first side wall, and a first channel is provided between the above thermal insulation pad and the above bottom plate, and the thermal conductivity of the above thermal insulation pad is less than 0.1W / (mK).

[0005] By arranging a thermal insulation pad on the first side wall of the battery cell, and the thermal conductivity of the thermal insulation pad is less than 0.1W / (mK), when a battery cell has thermal runaway, the thermal runaway high-temperature gas enters the first channel. When the thermal runaway high-temperature gas flows in the first channel and contacts the battery cell adjacent to it, the heat transfer is blocked by the thermal insulation pad. Therefore, the temperature of the battery cell adjacent to it will not rise sharply and thermal runaway will occur, thereby avoiding the spread of thermal runaway.

[0006] In an optional technical solution of the present invention, the flame retardant grade of the thermal insulation pad is V0, and the melting point of the thermal insulation pad is greater than 1000° C. If a battery cell with thermal runaway spontaneously ignites, the thermal insulation pad can prevent the fire from spreading to the adjacent battery cells, thereby preventing the entire battery pack from burning.

[0007] In an optional technical solution of the present invention, a plurality of spaced weak parts are provided on the thermal insulation pad along the length direction of the battery cell. A battery cell experiencing thermal runaway can discharge the thermal runaway gas into the first channel through the plurality of weak parts on the thermal insulation pad. 3-7 weak parts can be spaced along the length direction of a thermal insulation pad. The end of the thermal insulation pad and the support have overlapping parts, which can ensure that the first side wall of the battery cell 2 is completely covered by the thermal insulation pad, thereby preventing the spread of thermal runaway.

[0008] In an optional technical solution of the present invention, the thermal insulation pad includes a second main body and a weak part, and the thickness of the weak part is less than the thickness of the second main body. The thickness of the weak part is set to be less than the thickness of the second main body, and the thermal runaway gas can break through the weak part and enter the first channel.

[0009] In an optional technical solution of the present invention, the thickness H1 of the weak portion and the thickness H2 of the second main body of the thermal insulation pad satisfy: 1mm≤H2≤5mm, 0≤H1≤1mm.

[0010] In an optional technical solution of the present invention, the thermal insulation pad includes a second main body and a weak portion, and the weak portion is a through hole. The weak portion is set as a through hole, and the thermal runaway gas can directly enter the first channel from the through hole.

[0011] In an optional technical solution of the present invention, the shape of the through hole may be rectangular, circular, triangular, hexagonal or irregular.

[0012] In an optional technical solution of the present invention, the through hole is rectangular, and the length L1 and width L2 of the through hole satisfy: 20mm≤L1≤40mm, 0.1mm≤L2≤2mm. The through hole is designed to be an elongated rectangular hole. When a battery cell undergoes thermal runaway, high-pressure and high-temperature gas can easily enter the first channel through the through hole. After entering the first channel with a larger space, the thermal runaway gas is diluted, thereby preventing the thermal runaway gas from contacting adjacent battery cells through the through hole.

[0013] In an optional technical solution of the present invention, the thermal insulation pad includes aerogel and an outer film that wraps the aerogel, and the outer film is insulated. Aerogel has good thermal insulation and insulation properties and a high melting point, so it is arranged on the first side wall of the battery cell to prevent thermal runaway from spreading to adjacent battery cells.

[0014] In an optional technical solution of the present invention, a rubber strip is provided between the thermal insulation pad and the first side wall, and the thermal insulation pad can be bonded to the first side wall of the battery cell by the rubber strip.

[0015] In an optional technical solution of the present invention, the battery cell includes an edge seal, and at least two adhesive strips are arranged between the thermal insulation pad and the first side wall, and the adhesive strips are arranged on both sides of the edge seal. By arranging adhesive strips on both sides of the edge seal to bond the thermal insulation pad and the battery cell, an accommodation space can be reserved for the edge seal. A thermal insulation pad can be used to cover the first side wall under two adjacent battery cells, and the edge seals of the two battery cells are arranged between the two adhesive strips, and the edge seals of the two battery cells are opposite.

[0016] In an optional technical solution of the present invention, a fireproof layer is provided on the bottom plate, and the fireproof layer comprises a carbon ceramic material. After the thermal runaway gas enters the first channel, it will contact the bottom plate. The fireproof layer is provided on the bottom plate to prevent the bottom plate from being damaged by the thermal runaway high-temperature gas.

[0017] In an optional technical solution of the present invention, the support is provided with an air inlet and a second channel; the side wall of the box is provided with a third channel and a first explosion-proof valve; the air inlet, the second channel, the third channel and the explosion-proof valve are connected in sequence. After the thermal runaway gas enters the first channel, it contacts the support, enters the second channel through the air inlet on the support, passes through the third channel connected to the second channel, and finally is discharged from the battery pack through the explosion-proof valve.

[0018] In an optional technical solution of the present invention, the air inlet is arranged on the side of the support member facing the bottom plate. In this way, only when the air pressure in the box reaches a certain level, the bottom plate is impacted so that the air inlet on the support member facing the bottom plate is exposed, so that the thermal runaway gas can enter the second channel for exhaust, avoiding the risk of exhaust in non-thermal runaway conditions.

[0019] In an optional technical solution of the present invention, a second explosion-proof valve is provided on the box body, and the second explosion-proof valve is connected to the first channel. The thermal runaway gas entering the first channel can also be directly discharged out of the battery pack through the second explosion-proof valve on the box body.

[0020] The present invention further provides an electric device, the electric device of the present invention comprises the battery pack in the above optional technical solution. Through the arrangement of the above battery pack, the occurrence of thermal runaway and the spread of the thermal runaway can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional picture of the inside of the battery pack;

[0022] Figure 2 yes Figure 1 A bottom view with the base plate and the support members removed;

[0023] Figure 3 yes Figure 1 The front view in which the base plate and the supporting members are removed;

[0024] Figure 4 It is a schematic diagram of the thermal insulation pad and the rubber strip.

[0025] List of reference numerals:

[0026] Box body 1, bottom plate 1.1, support member 1.2;

[0027] Battery cell 2, first side wall 2.1, edge sealing 2.2;

[0028] Insulation pad 3, weak part 3.1, second main body part 3.2,

[0029] First channel 4;

[0030] Thermal management component 5;

[0031] Buffer 6;

[0032] Adhesive strip 7;

[0033] First adhesive 8. DETAILED DESCRIPTION

[0034] The following describes the 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 protection scope of the present invention.

[0035] In the description of the present invention, it is necessary to understand 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 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.

[0036] In the description of the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed" and "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 a direct connection, an indirect connection through an intermediate medium, or the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In order to prevent the battery pack from thermal runaway, Figure 1-4As shown, the present invention provides a battery pack, including: a box body 1, a battery cell 2 and a thermal insulation pad 3, the box body 1 includes a bottom plate 1.1 and a support member 1.2 arranged on the bottom plate 1.1; the battery cell 2 is arranged in the box body 1, the end of the battery cell 2 is arranged on the support member 1.2, and the first main body of the battery cell 2 includes a first side wall 2.1 facing the bottom plate; the thermal insulation pad 3 is arranged on the first side wall 2.1, and a first channel 4 is provided between the thermal insulation pad 3 and the bottom plate 1.1, and the thermal conductivity of the thermal insulation pad 3 is less than 0.1W / (mK). By arranging a thermal insulation pad 3 on the first side wall 2.1 of the battery cell 2, and the thermal conductivity of the thermal insulation pad 3 is less than 0.1W / (mK), when a battery cell 2 has thermal runaway, the thermal runaway high-temperature gas enters the first channel 4. When the thermal runaway high-temperature gas flows in the first channel 4 and contacts the battery cell 2 adjacent to it, the heat transfer is blocked by the thermal insulation pad 3. Therefore, the temperature of the battery cell 2 adjacent to it will not rise sharply and cause thermal runaway, thereby avoiding the spread of thermal runaway.

[0039] In an optional embodiment of the present invention, the flame retardant grade of the thermal insulation pad 3 is V0, and the melting point of the thermal insulation pad 3 is greater than 1000° C. If a battery cell 2 with thermal runaway spontaneously ignites, the thermal insulation pad 3 can prevent the fire from spreading to the adjacent battery cells 2, thereby preventing the entire battery pack from burning.

[0040] In an optional embodiment of the present invention, Figure 1 and Figure 3 As shown, the battery pack includes a plurality of battery cells 2 arranged along a first direction, and the battery cells 2 may be of the type of soft pack, square shell, blade, etc. The battery pack also includes a thermal management component 5 and a buffer 6. The thermal management component 5 is disposed between two adjacent battery cells 2, which can improve the heat transfer efficiency of the battery cells 2, and the surface of the battery cell 2 with the largest area can be bonded to the thermal management component 5 by a thermal conductive adhesive. The above-mentioned "battery cell-thermal management component-battery cell" arrangement unit is used as a battery cell group, and a buffer 6 is provided between two adjacent battery cell groups to bond the battery cell 2 and the buffer 6. By providing the buffer 6, the expansion problem of the battery cell 2 can be solved by setting the preload force in advance. The battery cell 2, the thermal management component 5 and the buffer 6 are all arranged along Figure 1 The heat management component 5 may be an integrally formed long cold plate or may be formed by splicing multiple cold plates. Figure 1 and Figure 3 In the third direction, the thermal management component 5 exceeds the battery cell 2, so that when the battery cell 2 has thermal runaway, the thermal management component 5 can provide a guide for the thermal runaway gas.

[0041] In an optional embodiment of the present invention, Figure 4As shown, along the length direction of the battery cell 2, a plurality of spaced weak parts 3.1 are arranged on the thermal insulation pad 3. The battery cell 2 that has thermal runaway can discharge the thermal runaway gas into the first channel 4 through the plurality of weak parts 3.1 on the thermal insulation pad 3. 3-7 weak parts 3.1 can be arranged at intervals along the length direction of a thermal insulation pad 3. The end of the thermal insulation pad 3 and the support member 1.2 have overlapping parts, which can ensure that the first side wall of the battery cell 2 is completely covered by the thermal insulation pad, thereby preventing the spread of thermal runaway.

[0042] In an optional embodiment of the present invention, the thermal insulation pad 3 includes a second main body portion 3.2 and a weak portion 3.1, and the thickness of the weak portion 3.1 is less than the thickness of the second main body portion 3.2. The thickness of the weak portion 3.1 is set to be less than the thickness of the second main body portion 3.2, and the thermal runaway gas can break through the weak portion 3.1 and enter the first channel 4.

[0043] In an optional embodiment of the present invention, the thickness H1 of the weak portion 3.1 and the thickness H2 of the second main portion 3.2 of the thermal insulation pad 3 satisfy: 1 ​​mm ≤ H2 ≤ 5 mm, 0

[0044] In an optional embodiment of the present invention, Figure 4 As shown, the thermal insulation pad 3 includes a second main body 3.2 and a weak portion 3.1, and the weak portion 3.1 is a through hole. The weak portion 3.1 is set as a through hole, and the thermal runaway gas can directly enter the first channel 4 from the through hole. The shape of the through hole can be rectangular, circular, triangular, hexagonal or irregular. When the above-mentioned through hole is rectangular, the length L1 and width L2 of the through hole meet: 20mm≤L1≤40mm, 0.1mm≤L2≤2mm. The through hole is designed to be an elongated rectangular hole. When the battery cell 2 has thermal runaway, the high-pressure and high-temperature gas can easily enter the first channel 4 through the through hole. After entering the first channel with a larger space, the thermal runaway gas is diluted, thereby preventing the thermal runaway gas from contacting the adjacent battery cell 2 through the through hole. L2 can be 0.1mm, 0.5mm, 1mm, 2mm, and L1 can be 20mm, 25mm, 30mm, 35mm, 40mm.

[0045] In an optional embodiment of the present invention, the thermal insulation pad 3 includes aerogel and an outer film that wraps the aerogel, and the outer film is insulated, for example, the outer film can be PET. Aerogel has good thermal insulation and insulation properties and a high melting point, so it is arranged on the first side wall 2.1 of the battery cell 2 to prevent thermal runaway from spreading to adjacent battery cells 2.

[0046] In an optional embodiment of the present invention,​ Figure 4 As shown, a glue strip 7 may be provided between the heat insulating pad 3 and the first side wall 2.1. The heat insulating pad 3 may be bonded to the first side wall 2.1 of the battery cell 2 by the glue strip 7.

[0047] In an optional embodiment of the present invention, Figure 3 As shown, the battery cell 2 includes an edge seal 2.2, and at least two rubber strips 7 are arranged between the thermal insulation pad 3 and the first side wall 2.1, and the rubber strips 7 are arranged on both sides of the edge seal 2.2. By arranging rubber strips 7 on both sides of the edge seal 2.2 to bond the thermal insulation pad 3 and the battery cell 2, an accommodation space can be reserved for the edge seal 2.2. A thermal insulation pad 3 can be used to cover the first side wall 2.1 under two adjacent battery cells 2, and a buffer member 6 is arranged between the two battery cells 2. The edge seals 2.2 of the two battery cells 2 are arranged between the two rubber strips 7, and the edge seals 2.2 of the two battery cells 2 are arranged opposite to each other, that is, the edge seals 2.2 of the two battery cells 2 are bent toward each other onto the first side wall 2.1 of the battery cell 2. As shown Figure 2 As shown, the “battery cell 2 - buffer 6 - battery cell 2” covered by two thermal insulation pads is arranged on the support member 1.2 as a whole, and specifically, can be bonded to the support member 1.2 by the first adhesive 8.

[0048] In an optional embodiment of the present invention, a fireproof layer is provided on the bottom plate 1.1, and the fireproof layer includes a carbon ceramic material, and the fireproof layer can be sprayed on the bottom plate 1.1. After the thermal runaway gas enters the first channel 4, it will contact the bottom plate 1.1. The fireproof layer is provided on the bottom plate 1.1 to prevent the bottom plate 1.1 from being damaged by the thermal runaway high-temperature gas.

[0049] In an optional embodiment of the present invention, an air inlet and a second channel are provided on the support 1.2; a third channel and a first explosion-proof valve are provided on the side wall of the box body 1; the air inlet, the second channel, the third channel and the explosion-proof valve are connected in sequence. After the thermal runaway gas enters the first channel 4, it contacts the support 1.2, enters the second channel through the air inlet on the support 1.2, passes through the third channel connected to the second channel, and is finally discharged from the battery pack by the explosion-proof valve. After the thermal runaway gas passes through the above three channels, the temperature can be lowered to avoid the discharge of the battery pack with open flames or excessively high temperatures, thereby avoiding harm to users.

[0050] In an optional embodiment of the present invention, the air inlet is arranged on the side of the support member 1.2 facing the bottom plate 1.1. In this way, only when the air pressure in the box body 1 reaches a certain level, the bottom plate 1.1 is impacted so that the air inlet of the support member 1.2 facing the bottom plate 1.1 is exposed, so that the thermal runaway gas can enter the second channel 4 for exhaust, avoiding the risk of exhaust in non-thermal runaway conditions.

[0051] In an optional embodiment of the present invention, a second explosion-proof valve is provided on the box body 1, and the second explosion-proof valve is connected to the first channel 4. The thermal runaway gas entering the first channel 4 can also be directly discharged out of the battery pack through the second explosion-proof valve on the box body 1.

[0052] The present invention also provides an electrical device, and the electrical device of the present invention includes the battery pack in the above optional embodiment. By setting the above battery pack, the situation of thermal runaway spreading in the electrical device can be avoided. The electrical device can be but not limited to a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0053] So far, the technical solutions of the present invention have been described in conjunction with the optional implementation modes shown in the accompanying drawings, but 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 implementation modes. 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: The box body comprises a bottom plate and a support member arranged on the bottom plate; A battery cell is disposed in the box, an end of the battery cell is disposed on the support member, and a first main body of the battery cell includes a first side wall facing the bottom plate; A thermal insulation pad is arranged on the first side wall, and a first channel is provided between the thermal insulation pad and the bottom plate, and the thermal conductivity of the thermal insulation pad is less than 0.1 W / (mK).

2. The battery pack according to claim 1, characterized in that: The flame retardant grade of the thermal insulation pad is V0.

3. The battery pack according to claim 2, characterized in that: The melting point of the thermal insulation pad is greater than 1000°C.

4. The battery pack according to any one of claims 1 to 3, characterized in that: Along the length direction of the battery cell, the thermal insulation pad is provided with a plurality of spaced apart weak parts.

5. The battery pack according to any one of claims 1 to 3, characterized in that: The thermal insulation pad includes a second main body portion and a weak portion, and the thickness of the weak portion is smaller than the thickness of the second main body portion.

6. The battery pack according to claim 5, characterized in that: The thickness H1 of the weak portion and the thickness H2 of the second main portion satisfy: 1mm≤H2≤5mm, <H1≤1mm。 7. The battery pack according to any one of claims 1 to 3, characterized in that: The thermal insulation pad comprises a second main body portion and a weak portion, and the weak portion is a through hole.

8. The battery pack according to claim 7, characterized in that: The through hole may be in a rectangular, circular, triangular, hexagonal or irregular shape.

9. The battery pack according to claim 8, characterized in that: The through hole is rectangular, and the length L1 and width L2 of the through hole satisfy: 20mm≤L1≤40mm, 0.1mm≤L2≤2mm.

10. The battery pack according to any one of claims 1 to 3, characterized in that: The thermal insulation pad comprises an aerogel and an outer envelope wrapping the aerogel, wherein the outer envelope is insulating.

11. The battery pack according to any one of claims 1 to 3, characterized in that: A rubber strip is arranged between the thermal insulation pad and the first side wall.

12. The battery pack according to claim 11, characterized in that: The battery cell comprises a sealed edge, at least two rubber strips are arranged between the thermal insulation pad and the first side wall, and the rubber strips are arranged on both sides of the sealed edge.

13. The battery pack according to any one of claims 1 to 3, characterized in that: A fireproof layer is arranged on the bottom plate, and the fireproof layer comprises carbon ceramic material.

14. The battery pack according to any one of claims 1 to 3, characterized in that: The support member is provided with an air inlet hole and a second channel; A third channel and a first explosion-proof valve are arranged on the side wall of the box; The air inlet, the second channel, the third channel and the explosion-proof valve are connected in sequence.

15. The battery pack according to claim 14, characterized in that: The air inlet hole is arranged on a side of the support member facing the bottom plate.

16. The battery pack according to claim 15, characterized in that: The box body is provided with a second explosion-proof valve, and the second explosion-proof valve is communicated with the first channel.

17. An electrical device comprising the battery pack according to any one of claims 1 to 16.

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