A battery pack

Abstract

The application relates to the battery technical field and discloses a battery pack, which comprises a single battery, a protection assembly and the like. The single battery comprises connected mounting wall surfaces and enclosing wall surfaces, the mounting wall surfaces are provided with explosion-proof valves, and the connecting seams of the mounting wall surfaces and the enclosing wall surfaces are located in butt joint areas. The protection assembly comprises a first isolation layer and a second isolation layer which are arranged in layers along the thickness direction of the protection assembly. The protection assembly covers at least part of the butt joint areas, and the first isolation layer is close to the butt joint areas. The thermal conductivity coefficient of the first isolation layer is k1 W / (m*K), the elastic modulus is e1 MPa, and the thickness is d1 mm. The thermal conductivity coefficient of the second isolation layer is k2 W / (m*K), the elastic modulus is e2 MPa, and the thickness is d2 mm. K1 > k2, e1 < e2, and the range of d1 / d2 is 3-20. The application strengthens the protection of the butt joint areas on the single battery, reduces the risk of oblique ejection due to the damage of the butt joint areas when the single battery is in thermal runaway, and improves the operation stability of other single batteries.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] The battery pack contains multiple individual cells. During the operation of the battery pack, when a single cell experiences thermal runaway, its high-temperature ejected material can easily affect surrounding cells, causing the thermal runaway to spread and leading to an accident in which a large number of cells go out of control. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a battery pack to reduce the risk of thermal runaway propagation of individual cells within the battery pack.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] A battery pack, comprising:

[0006] A single cell includes a mounting wall and an enclosing wall that are connected to each other. The mounting wall is equipped with an explosion-proof valve, and the connection seam between the mounting wall and the enclosing wall is located in the docking area.

[0007] A protective component is disposed on one side of a single cell. The protective component includes a first isolation layer and a second isolation layer that are layered along its thickness direction. The protective component covers at least a portion of the docking area, and the first isolation layer of the protective component is disposed close to the docking area.

[0008] The thermal conductivity of the first isolation layer is k1W / (m·K), the elastic modulus is e1MPa, and the thickness is d1mm; the thermal conductivity of the second isolation layer (320) is k2W / (m·K), the elastic modulus is e2MPa, and the thickness is d2mm; and k1>k2, e1<e2, and the range of d1 / d2 is 3-20.

[0009] As can be seen from the above technical solutions, one aspect of this disclosure provides a battery pack, which includes individual cells and a protective assembly. The individual cell specifically includes a mounting wall and an enclosing wall connected together. The mounting wall is provided with an explosion-proof valve, and the connection seam between the mounting wall and the enclosing wall is located in the docking area. The protective assembly is disposed on one side of the individual cell and includes a first isolation layer and a second isolation layer disposed in layers along its thickness direction. The protective assembly covers at least a portion of the docking area, thereby strengthening the protection of the docking area on the individual cell. When the corresponding individual cell experiences thermal runaway, the docking area, as a weak connection area, can reduce the risk of damage. The individual cell is guided to be ejected at the location of the explosion-proof valve, and will not be ejected obliquely into the working area of ​​other individual cells due to damage to the docking area, thus reducing the risk of thermal spread. It should also be noted that the first isolation layer of the protective component is positioned close to the docking area. The first and second isolation layers use materials with different properties. Specifically, the thermal conductivity of the first isolation layer is k1 W / (m·K), and the elastic modulus is e1 MPa, while the thermal conductivity of the second isolation layer is k2 W / (m·K), and the elastic modulus is e2 MPa, where k1 > k2 and e1 < e2. This ensures that the first isolation layer has superior elasticity compared to the second isolation layer. The stacked structure along the thickness direction allows the protective component to have an elastic effect through the first isolation layer. When embedded between two individual cells, it can maintain a compressed state through elasticity, ensuring the stability of the protective component's position between the two individual cells. The second isolation layer, on the other hand, has superior thermal insulation performance compared to the first isolation layer. With the protective component stably positioned between the individual cells, it can block the heat transfer path through the superior thermal insulation effect of the second isolation layer. In the event of thermal runaway in a single individual cell, the protective component can effectively block heat and reduce the risk of thermal runaway spreading inside the battery pack.

[0010] Furthermore, since the spacing between individual cells needs to meet the energy density requirements of the battery pack, the thickness of the protective component is limited. In this disclosure, the thickness of the first insulating layer is d1mm and the thickness of the second insulating layer is d2mm. The range of d1 / d2 is 3-20. By limiting the thickness ratio of the first and second insulating layers, the overall elasticity and heat insulation effect of the protective component are balanced. This allows it to have sufficient heat insulation performance to meet the isolation of heat transfer paths while being stably set between individual cells, ensuring that the protective component can reduce the risk of thermal runaway propagation within the battery pack. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the internal structure of a battery pack according to an embodiment of the present invention;

[0013] Figure 2 This is a schematic diagram of the structure of the protective component and the single battery provided in an embodiment of the present invention;

[0014] Figure 3 A schematic diagram of the cooperation structure between the protective component and one end of a single battery cell provided in an embodiment of the present invention;

[0015] Figure 4 This is a schematic diagram of the end face structure of a protective component provided in an embodiment of the present invention;

[0016] Figure 5 A cross-sectional structural schematic diagram of a protective component provided in an embodiment of the present utility model;

[0017] Figure 6 A schematic diagram of the clamping structure between two individual batteries provided in an embodiment of the present invention;

[0018] Figure 7 A cross-sectional structural diagram of a protective component including a third isolation layer is provided for an embodiment of this utility model;

[0019] Figure 8 This is a schematic diagram of a structure in which the end of the first isolation layer protrudes more than the end of the second isolation layer, according to an embodiment of the present invention.

[0020] Figure 9 A schematic diagram of the structure of a protective assembly with a support portion assembled on a single battery cell according to an embodiment of the present invention;

[0021] Figure 10 This is an isometric schematic diagram of a protective component provided in an embodiment of the present invention;

[0022] Figure 11 This is an isometric schematic diagram of a protective component provided in another embodiment of the present invention.

[0023] in:

[0024] 10-Explosion-proof valve; 20-Single battery; 210-First surface; 220-Second surface; 230-Mounting wall surface; 240-Enclosing wall surface; 250-Dating area; 30-Protective component; 310-First isolation layer; 320-Second isolation layer; 330-Third isolation layer; 340-Support part. Detailed Implementation

[0025] The core of this application is to disclose a battery pack that reduces the risk of thermal runaway propagation in individual cells.

[0026] To enable those skilled in the art to better understand the present application, embodiments of the present application will be described below with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the utility model described in the claims. Additionally, the complete content of the structures represented in the following embodiments is not limited to those necessary for the solution of the utility model described in the claims.

[0027] like Figure 1 As shown, one aspect of this disclosure provides a battery pack. It should be noted that the battery pack, as a rechargeable battery, is the power source for new energy vehicles. Specifically, it includes a battery pack composed of multiple battery cells, which are combined in series and parallel or both to form a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage and low-voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components. The above components are placed in a housing, which is divided into upper and lower parts and sealed together, specifically by a cover plate, forming a complete functional unit that can directly output electrical energy.

[0028] Battery packs are widely used in electric vehicles, hybrid vehicles, energy storage systems, and other applications requiring high capacity and high voltage. They are a key component of electric energy systems, providing a higher level of energy storage and management to meet the needs of different applications.

[0029] like Figure 1 and Figure 2 As shown in the embodiments provided in this disclosure, the battery pack includes individual battery cells 20. It should be noted that the individual battery cell 20 can store chemical energy and controllably convert this chemical energy into electrical energy. In recyclable batteries, after discharge, the active materials can be activated by charging for continued use. Typically, the individual battery cell 20 includes a casing and a cell disposed within the casing. Specifically, the casing is a component that provides a space to house electrode assemblies and other parts and isolate them from the external environment. The casing generally includes a body with an opening at at least one end and a receiving cavity. The opening of the casing can be closed by a cover plate to seal and isolate the internal environment of the individual battery cell from the external environment. The casing material includes, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and aluminum-plastic film.

[0030] Specifically, such as Figure 3 As shown, the single-cell battery 20 has a mounting wall 230, and an explosion-proof valve 10 is provided on the mounting wall 230. It should be noted that the explosion-proof valve 10 is a component or part that can be actuated to release internal pressure or temperature when the internal pressure or temperature of the single-cell battery reaches a predetermined threshold. During battery use, the explosion-proof valve 10 is mainly used to allow gas to escape from the battery to reduce internal pressure in the event of thermal runaway or other situations, preventing excessive increase in internal pressure that could cause deformation or explosion. The material of the explosion-proof valve 10 is not limited, including but not limited to aluminum, steel, alloys, etc. The shape of the explosion-proof valve 10 is not limited, such as square, oblong, elliptical, racetrack-shaped, etc. The type of explosion-proof valve 10 is not limited, such as a notched explosion-proof valve 10, which can be formed by stamping or laser etching.

[0031] The single cell 20 also has an enclosing wall 240 connected to the mounting wall 230, and the connection seam between the mounting wall 230 and the enclosing wall 240 of the single cell 20 is located in the docking area 250. It should be noted that, under ideal conditions, the single cell 20 will only damage the explosion-proof valve 10 area when it is thermally runaway. However, due to the bending connection structure or splicing of the mounting wall 230 and the enclosing wall 240, the docking area 250 will be relatively weak and easily damaged when the single cell 20 is thermally runaway.

[0032] Building upon this, the battery pack also includes a protective component 30, which covers at least a portion of the docking area 250 to provide enhanced protection for the docking area 250. Specifically, the protective component 30 includes a first insulating layer 310 and a second insulating layer 320 arranged in layers along its thickness direction. The first insulating layer 310 is positioned close to the docking area 250, and its elasticity allows for a tight enclosure between the protective component 30 and the docking area 250. This ensures that in the event of thermal runaway of a single battery cell 20, the docking area 250 is protected by the protective component 30, preventing damage to the single battery cell 20 and the oblique ejection of high-temperature ejected materials. These materials could then fall directly into the working areas of other single batteries 20, causing them to fail, thus improving the operational stability of the battery pack.

[0033] Furthermore, based on the above embodiments, the protective component 30 needs to effectively cover the docking area 250 in order to meet the enhanced protection requirements for the docking area 250. Therefore, the protective component 30 needs to form an effective connection with the mounting wall 230 to meet the protection requirements for the docking area 250.

[0034] In some embodiments of this disclosure, the protective component 30 covers and connects to at least a portion of the mounting wall surface 230 of the individual battery 20 via a first insulating layer 310. On the mounting wall surface 230 of the individual battery 20, the first insulating layer 310 can extend beyond the second insulating layer 320 to meet the connection requirements with the mounting wall surface 230. In other embodiments of this disclosure, the protective component 30 covers and connects to at least a portion of the mounting wall surface 230 of the individual battery 20 via a second insulating layer 320. Similarly, on the mounting wall surface 230 of the individual battery 20, the second insulating layer 320 can extend beyond the second insulating layer 320 and have a certain degree of height change to adhere to and be fixedly connected to the mounting wall surface 230.

[0035] Specifically, such as Figure 4 As shown, for the first isolation layer 310 and the second isolation layer 320 of the protective component 30 arranged in layers along its thickness direction, in order to meet the structural and functional requirements of the protective component 30, the first isolation layer 310 and the second isolation layer 320 in the protective component 30 provided in this embodiment use materials with different properties to meet the composite performance requirements of the protective component 30.

[0036] Specifically, the thermal conductivity of the first insulating layer 310 is k1 W / (m·K), and the elastic modulus is e1 MPa, while the thermal conductivity of the second insulating layer 320 is k2 W / (m·K), and the elastic modulus is e2 MPa, and k1 > k2, e1 < e2. Compared with the first insulating layer 310 and the second insulating layer 320, the first insulating layer 310 has a relatively superior elastic effect. The structure of being stacked along the thickness direction makes the protective component 30 elastic through the first insulating layer 310, and can maintain a good fit with the single battery 20 through the elastic effect.

[0037] The second insulating layer 320 has lower thermal conductivity than the first insulating layer 310, meaning it has superior thermal insulation performance. Although it has less elasticity, it can more effectively isolate heat than the first insulating layer 310. The protective component 30 blocks the heat transfer path through the excellent thermal insulation effect of the second insulating layer 320. In the event of thermal runaway in a single cell 20, the protective component 30 can effectively block heat transfer, thereby reducing the risk of thermal runaway spreading between different cells 20 within the battery pack 10.

[0038] In the above embodiments, the protective component 30 achieves elastic compression and fixation, as well as effective heat insulation, through a composite structure. Furthermore, because the spacing between the individual battery cells 20 needs to meet the energy density requirements of the battery pack and cannot be too large, the space available for assembling the protective component 30 between the individual battery cells 20 is limited; that is, the total thickness of the protective component 30 is limited. Based on this, as... Figure 5 and Figure 6 As shown, in some embodiments of this disclosure, the thickness of the first isolation layer 310 is d1mm, and the thickness of the second isolation layer 320 is d2mm. Therefore, the range of d1 / d2 is 3-20, specifically 3, 6, 9, 12, 15, 18, or 20. It should be noted that if d1 / d2 is less than 3, the thickness proportion of the first isolation layer 310 in the protective assembly 30 is too small, resulting in poor overall elasticity of the protective assembly 30. This makes the compression assembly process more cumbersome, and there is a risk that the protective assembly 30 may detach from the single battery 20 due to insufficient elasticity and compression. Conversely, if d1 / d2 is greater than 20, the thickness proportion of the second isolation layer 320 is too small, although the protection... The protective component 30 can maintain a stable setting between the individual cells 20. However, the second insulating layer 320, which bears the main heat insulation area in the protective component 30, is too thin, resulting in insufficient heat insulation capacity and a significant risk of thermal runaway propagation. Therefore, in this embodiment, the thickness ratio d1 / d2 of the first insulating layer 310 and the second insulating layer 320 is limited to 3-20, so that the overall elasticity and heat insulation effect of the protective component 30 are balanced. This allows it to maintain a stable setting between the individual cells 20 while having sufficient heat insulation performance to isolate the heat transfer path, ensuring that the protective component 30 can reduce the risk of thermal runaway propagation within the battery pack.

[0039] It should be noted that in the above embodiments, the thickness d1mm of the first isolation layer 310 and the thickness d2mm of the second isolation layer 320 are both their thicknesses after being fully assembled on one side of the single cell 20. Further, the battery pack provided in this embodiment includes at least two single cells 20, each of which can be provided with a corresponding protective component 30 to achieve thermal isolation of adjacent single cells 20 and to provide key protection for the docking area 250 on each single cell 20. It should also be noted that, in order to improve the compactness and integrity of the internal structure of the battery pack, in some embodiments, the two protective components 30 between adjacent single cells 20 can be fixedly connected as a single structure, so as to achieve connection with the single cell 20 through the first isolation layers 310 on both sides facing the single cell 20. Simultaneously, the two protective components 30 between adjacent single cells 20 can also be integrally formed to improve structural compactness. Furthermore, for the two integrally formed protective components 30, they can share a second isolation layer 320, and achieve thermal isolation through the first isolation layers 310 on both sides docking with the single cells 20 on both sides respectively.

[0040] Furthermore, in some embodiments of this disclosure, such as Figure 7As shown, the protective component 30 also includes a third insulating layer 330 stacked with the first insulating layer 310 and the second insulating layer 320 along its thickness direction. Here, "stacked" means that the first insulating layer 310, the second insulating layer 320, and the third insulating layer 330 are parallel and bonded together, and their thickness directions are the same. The added third insulating layer 330, like the first insulating layer 310 and the second insulating layer 320, also has heat insulation capabilities, thus making the overall heat insulation capability of the protective component 30 stronger and more effectively blocking the heat spread path, ensuring the safety of the normally operating single battery cell 20.

[0041] Based on the above embodiments, the third isolation layer 330 can be made of the same material as the second isolation layer 320. That is, compared with the first isolation layer 310, the third isolation layer 330 also has superior heat insulation capability and relatively poor elasticity. At the same time, the third isolation layer 330 is disposed on the side of the first isolation layer 310 away from the second isolation layer 320, so that the protective assembly 30 forms a structure in which the third isolation layer 330 and the second isolation layer 320 clamp the first isolation layer 310 from opposite sides. Along the thickness direction of the protective assembly 30, the third isolation layer 330 and the second isolation layer 320 can achieve two effective heat insulation barriers from both sides, while the first isolation layer 310 can provide elasticity between the two, so that the third isolation layer 330 and the second isolation layer 320 can effectively fit against the outer walls of the two individual battery cells 20 on both sides under the elastic action, thus maintaining their stable placement in the heat insulation position.

[0042] In addition, it should be noted that, as Figure 7 As shown, the third isolation layer 330 and the second isolation layer 320 can have the same size and configuration, and the third isolation layer 330 and the second isolation layer 320 are symmetrically arranged about the first isolation layer 310, so that the protective component 30 has a uniform heat insulation effect on both sides. At the same time, during the assembly process, the assembler does not need to distinguish the front and back of the protective component 30, thus reducing the assembly difficulty of the protective component 30 in the battery pack 10.

[0043] To further optimize the above technical solution, in some embodiments of this disclosure, such as Figure 7As shown, the thickness of the third isolation layer 330 is d3mm, and the thickness ratio of the third isolation layer 330 to the second isolation layer 320, d3 / d2, ranges from 0.9 to 1.1, specifically 0.9, 1.0 or 1.1. Specifically, if d3 / d2 is less than 0.9 or greater than 1.1, the thickness difference between the third isolation layer 330 and the second isolation layer 320 is large. For the protective component 30 as a whole, the heat insulation effect on both sides in the thickness direction is significantly different. For individual cells 20 with similar operating states on both sides, the protective component 30 with a large difference in heat insulation effect on both sides in the thickness direction has the risk of effective heat insulation in one direction but insufficient heat insulation in the reverse direction. When the individual cell 20 on the side with weaker heat insulation capacity experiences thermal runaway, heat will penetrate into the first isolation layer 310, thereby damaging the structure of the protective component 30 and affecting its service life and heat insulation effect. Therefore, d3 / d2 needs to be in the range of 0.9-1.1, and in some preferred embodiments, d3 / d2 is close to or equal to 1, so that the heat insulation capacity on both sides of the protective component 30 is more uniform, so that it can have a uniform heat blocking effect on both sides and have a similar protective effect on the individual cells 20 on both sides.

[0044] Furthermore, based on the above embodiments, the overall heat insulation performance of the protective component 30 is further improved due to the provision of the third insulating layer 330. However, given a fixed total thickness, the elasticity of the protective component 30 decreases. Therefore, in the corresponding embodiments, the ratio of the thickness of the first insulating layer 310 to the thickness of the second insulating layer 320, d1 / d2, ranges from 4 to 20, specifically 4, 8, 12, 16, or 20. It should be noted that the provision of the third insulating layer 330 enhances the overall elasticity of the protective component 30, ensuring that the protective component 30 can be stably fitted and embedded between the two individual battery cells 20.

[0045] In other embodiments of this disclosure, the third isolation layer 330 may also be made of the same material as the first isolation layer 310. The third isolation layer 330 and the first isolation layer 310 are disposed on opposite sides of the second isolation layer 320 in its thickness direction, forming a structure in which the third isolation layer 330 and the first isolation layer 310 clamp the second isolation layer 320 from both sides. It should be noted that, since the third isolation layer 330 and the first isolation layer 310 have superior elasticity compared to the second isolation layer 320, the third isolation layer 330 and the first isolation layer 310 disposed on both sides can better fit against the sidewalls of the individual battery cells 20 through their elastic deformation, ensuring that the protective component 30 can be stably disposed in the target position. The second isolation layer 320, clamped in the middle, can avoid direct contact with the individual battery cells 20, reducing the risk of impact damage due to its exposure, thus maintaining the structural integrity of the second isolation layer 320 and providing a stable heat insulation effect.

[0046] Based on the above embodiments, such as Figure 7 As shown, along the height direction of the single cell 20, the height of the third isolation layer 330 is equal to that of the first isolation layer 310. That is, for the protective component 30, during the process of contacting the outer wall of the single cell 20 through the third isolation layer 330 and the first isolation layer 310 on both sides, the third isolation layer 330 and the first isolation layer 310 with the same height can apply elastic pressing force in the same height area, thereby avoiding the risk of skewing due to uneven force on both sides of the protective component 30.

[0047] Furthermore, it is preferable that the third isolation layer 330 has the same structure as the first isolation layer 310, with the same size and symmetrically arranged about the second isolation layer 320. This also allows the protective component 30 to have a uniform elastic effect on both sides. During the assembly process, the assembler does not need to distinguish the front and back of the protective component 30, thus reducing the assembly difficulty of the protective component 30 in the battery pack 10.

[0048] Furthermore, in order to reduce the production difficulty of the protective component 30, in some embodiments of this disclosure, at least one end face of the first isolation layer 310 and the second isolation layer 320 is flush along the height direction of the single cell 20. For the protective component 30 with a composite layer structure, the structure with at least one end face flush can enable the two isolation layers to have a unified positioning reference, thereby making the finished protective component 30 have good uniformity and making the performance difference of the protective components 30 in the same batch small.

[0049] It should also be noted that in some preferred embodiments of this disclosure, the flush end faces on the first isolation layer 310 and the second isolation layer 320 are preferably disposed facing the upper surface of the single cell 20, so that the visible upper surface of the single cell 20 in the battery pack remains flush, reducing the assembly difficulty of electrical components such as busbars.

[0050] In other embodiments of this disclosure, such as Figure 8 As shown, along the height direction of the single cell 20, one end face of the first insulating layer 310 protrudes from the second insulating layer 320, that is, the height dimension of the first insulating layer 310 is greater than that of the second insulating layer 320. During the manufacturing process of the protective component 30, the second insulating layer 320 can be completely bonded and fixed to the first insulating layer 310. The second insulating layer 320 has a certain bonding error, which reduces its bonding difficulty. The second insulating layer 320, which bears the main heat insulation effect, can be covered and protected by the first insulating layer 310, thus maintaining the structural integrity and being stably set in the preset position between the single cells 20.

[0051] Furthermore, based on the above embodiments, such as Figure 8As shown, the protrusion distance d4mm of the end face of the first isolation layer 310 relative to the second isolation layer 320 ranges from 0.6mm to 3mm, specifically 0.6mm, 1.5mm, 2.1mm, 2.5mm, or 3mm. It should be noted that if the protrusion distance of the end face of the first isolation layer 310 relative to the second isolation layer 320 is less than 0.6mm, the height difference between the first isolation layer 310 and the second isolation layer 320 is small, making it difficult to ensure that the second isolation layer 320 is completely bonded to the first isolation layer 310, resulting in high production difficulty and a higher defect rate for the protective component 30. Conversely, if the protrusion distance of the end face of the first isolation layer 310 relative to the second isolation layer 320 is greater than 3mm, there will be significant waste of the elastic layer, and a large portion of the structure of the protective component 30 in its height direction will lack sufficient heat insulation capacity. Given a fixed weight specification for the protective component 30, the weight occupied by the first isolation layer 310 will be excessive, leading to insufficient second isolation layer 320 and poor heat insulation performance of the protective component 30. Therefore, the protrusion distance d4mm of the end face of the first isolation layer 310 based on the second isolation layer 320 is limited to 0.6mm-3mm to balance the production difficulty and heat insulation capability of the protective component 30.

[0052] Furthermore, it should be noted that in some embodiments, the end face of the second isolation layer 320 can also protrude from the end face of the first isolation layer 310, so that the first isolation layer 310 can be bonded to the second isolation layer 320 during the production process of the protective component 30.

[0053] Furthermore, in the battery pack provided in this embodiment, the single cell 20 includes a first surface 210 and a second surface 220 located at both ends in the height direction. The explosion-proof valve 10 is disposed on the first surface 210. The explosion-proof valve 10 is a channel for the ejection of high-temperature gas during the thermal runaway of the single cell 20. That is, when the single cell 20 is thermally runaway, the explosion-proof valve 10 and the area of ​​the first surface 210 are high-temperature areas on the single cell 20. On this basis, the protective component 30 is flush with the first surface 210 at one end in the height direction of the single cell 20, or the protective component 30 protrudes from the first surface 210 at one end in the height direction of the single cell 20, so as to ensure that the protective component 30 can effectively block the first surface 210 of the adjacent single cell 20 in the height direction, that is, to block the high-temperature area and cut off the heat transfer path of the adjacent single cell 20, thereby effectively blocking the spread of thermal runaway.

[0054] Based on the above embodiments, such as Figure 9As shown, the protective component 30 also includes a support portion 340. Specifically, the support portion 340 is fixedly connected to one or both of the first isolation layer 310 and the second isolation layer 320, and the support portion 340 overlaps and is fixed to a portion of the first surface 210 of the single cell 20, so as to support the first isolation layer 310 and the second isolation layer 320 through the abutment limiting effect, thereby reducing the risk of the first isolation layer 310 and the second isolation layer 320 slipping and failing in the gap of the single cell 20, and improving the thermal insulation stability of the protective component 30.

[0055] It should also be noted that the support portion 340 can also be made of heat-insulating material to effectively block the first surface 210 of the adjacent single cell 20 and improve the heat insulation effect of the protective component 30; and the support portion 340, as a structure that overlaps and is fixed to the first surface 210 of the single cell 20, can be formed by extending the first isolation layer 310 or the second isolation layer 320, or it can be formed by extending the stacked structure of the first isolation layer 310 and the second isolation layer 320.

[0056] Furthermore, in the embodiments of this disclosure, the protective component 30 extends within the battery pack 10 so that it can simultaneously isolate multiple adjacent individual battery cells 20 along the length of the protective component 30, thereby improving the utilization efficiency of the protective component 30.

[0057] In some embodiments of this disclosure, such as Figure 10 As shown, the second isolation layer 320 and the first isolation layer 310 have the same length and are fitted together. That is, in the length direction of the protective component 30, the second isolation layer 320 and the first isolation layer 310 are both continuously arranged isolation layer structures. The protective component 30 has elasticity and heat insulation effect in each area in its length direction to meet the requirements of installation and use. The protective component 30 only needs to be assembled in the gap of the single battery 20 to meet the protection requirements to prevent the spread of thermal runaway.

[0058] In other embodiments, such as Figure 11 As shown, in the length direction of the protective component 30, only the first insulating layer 310 is a continuous structure. This continuous first insulating layer 310 provides a support base, allowing multiple second insulating layers 320 to be spaced apart along the length direction of the first insulating layer 310. During use in the battery pack 10, the protective component 30 only needs to align the area of ​​the first insulating layer 310 containing the second insulating layer 320 with the sidewall of the individual battery cell 20 to ensure the heat insulation effect of the protective component 30 on adjacent individual batteries 20. Compared to a continuous second insulating layer 320, the spaced second insulating layers 320 along the length direction of the first insulating layer 310 improve the heat insulation accuracy of the protective component 30 and reduce its production cost.

[0059] Based on the above embodiments, the number of second isolation layers 320 can be the same as the number of individual battery cells 20 for heat insulation. That is, in the length direction of the protective component 30, each individual battery cell 20 has one and only one corresponding second isolation layer 320. During the assembly process, the second isolation layers 320 are also set one-to-one with the individual battery cells 20. The gap between adjacent second isolation layers 320 corresponds to the gap between two individual battery cells 20 in the length direction of the protective component 30, so as to improve the utilization efficiency of the second isolation layer 320.

[0060] Similarly, in the length direction of the protective component 30, the number of second isolation layers 320 can also be greater than the number of individual cells 20, so that the protective component 30 has multiple assembly positions in the battery pack 10, thereby increasing the assembly freedom of the protective component 30.

[0061] Furthermore, in the battery pack provided in the embodiments of this disclosure, in order to meet the performance requirements of the protective component 30, in some embodiments, for the first insulating layer 310, the range of k1W / (m·K) is 0.5W / (m·K)-5W / (m·K), specifically it can be 0.5W / (m·K), 1.5W / (m·K), 2.5W / (m·K), 3.5W / (m·K), 4.5W / (m·K) or 5W / (m·K); the range of e1MPa is 0.1MPa-15MPa, specifically it can be 0.1MPa, 1MPa, 2MPa, 3MPa, 4MPa or 5MPa; the range of d1mm is 1mm-5mm, specifically it can be 1mm, 2mm, 3mm, 4mm or 5mm; so that the first insulating layer 310 has a certain heat insulation effect, while its elastic effect meets the stable setting of the protective component 30 in the gap of the single cell 20, and has sufficient thickness to meet the structural support requirements.

[0062] In some embodiments, the first insulating layer 310 may be made of solid silicone, and the thermal conductivity of the solid silicone constituting the first insulating layer 310 is 0.8 W / (m·K)-5 W / (m·K), and its elastic modulus is 0.5 MPa-10 MPa; in other embodiments, the first insulating layer 310 may be made of thermally conductive gel, and the corresponding thermally conductive gel has a thermal conductivity of 1 W / (m·K)-5 W / (m·K), and its elastic modulus is 0.1 MPa-5 MPa; in some other embodiments, the first insulating layer 310 may also be made of soft thermally conductive polyurethane gasket, with a corresponding thermal conductivity of 0.5 W / (m·K)-3 W / (m·K), and its elastic modulus is 1 MPa-15 MPa.

[0063] For the second isolation layer 320, the range of k2W / (m·K) is 0.1MPa-15MPa, specifically 0.1W / (m·K), 5W / (m·K), 10W / (m·K), or 15W / (m·K); the range of e2MPa is 1MPa-50MPa, specifically 1MPa, 10MPa, 20MPa, 30MPa, 40MPa, or 50MPa; and the range of d2mm is 0.1mm-0.8mm, specifically 0.1mm, 2mm, 4mm, 5mm, or 8mm. This ensures that the second isolation layer 320 has a certain degree of elasticity and excellent thermal insulation performance, effectively blocking the heat transfer path in the event of thermal runaway of the single cell 20. At the same time, by limiting its thickness, the thermal barrier thickness of the second isolation layer 320 is ensured. By limiting the parameters of the first isolation layer 310 and the second isolation layer 320, the composite structure protective component 30 is ensured to have a stable elastic structural foundation and effective thermal insulation effect.

[0064] It should be noted that in some embodiments of this disclosure, the second isolation layer 320 may be made of ceramic silicone rubber, and the thermal conductivity of the ceramic silicone rubber constituting the second isolation layer 320 is 0.05 W / (m·K)-0.2 W / (m·K), and its elastic modulus is 2 MPa-50 MPa; while in other embodiments, the second isolation layer 320 may be made of an elastomer encapsulating aerogel, and the corresponding thermal conductivity of the second isolation layer 320 is 0.015 W / (m·K)-0.03 W / (m·K), and its elastic modulus is 1 MPa-20 MPa.

[0065] It should also be noted that the first and second isolation layers are fixed by adhesive bonding. Adhesive bonding is applicable to a wide range of materials, is lightweight, has high shear strength, is easy to operate, and has a low connection cost.

[0066] The terms "first," "second," "left side," and "right side," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units may not be defined in the listed steps or units, but may include steps or units not listed.

[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery pack, characterized in that, include: A single battery cell (20) includes a mounting wall (230) and an enclosing wall (240) connected to each other. The mounting wall (230) is provided with an explosion-proof valve (10). The connection seam between the mounting wall (230) and the enclosing wall (240) is located in the docking area (250). A protective component (30) is disposed on one side of the single cell (20). The protective component (30) includes a first isolation layer (310) and a second isolation layer (320) disposed in layers along its thickness direction. The protective component (30) covers at least a portion of the docking area (250), and the first isolation layer (310) of the protective component (30) is disposed close to the docking area (250). The first insulating layer (310) has a thermal conductivity of k1W / (m·K), an elastic modulus of e1MPa, and a thickness of d1mm; the second insulating layer (320) has a thermal conductivity of k2W / (m·K), an elastic modulus of e2MPa, and a thickness of d2mm; and k1>k2, e1<e2, and the range of d1 / d2 is 3-20.

2. The battery pack as described in claim 1, characterized in that, The first isolation layer (310) covers at least a portion of the area connected to the mounting wall (230) and is spaced apart from the explosion-proof valve (10), or, The second isolation layer (320) covers at least a portion of the area connected to the mounting wall (230) and is spaced apart from the explosion-proof valve (10).

3. The battery pack as described in claim 1, characterized in that, It includes at least two spaced individual cells (20), and each individual cell (20) is provided with a corresponding protective component (30) to at least partially cover and protect the corresponding docking area (250).

4. The battery pack as described in claim 3, characterized in that, The protective component (30) is embedded between adjacent single cells (20), and the two protective components (30) between adjacent single cells (20) are fixedly connected or integrally formed.

5. The battery pack as described in claim 1, characterized in that, The protective component (30) further includes a third isolation layer (330) stacked along the thickness direction with the first isolation layer (310) and the second isolation layer (320).

6. The battery pack as described in claim 5, characterized in that, The third isolation layer (330) is disposed on the side of the first isolation layer (310) away from the second isolation layer (320), and the third isolation layer (330) is made of the same material as the second isolation layer (320).

7. The battery pack as described in claim 6, characterized in that, The thickness of the third isolation layer (330) is d3mm, and the range of d3 / d2 is 0.9-1.

1.

8. The battery pack as described in claim 6, characterized in that, The range of d1 / d2 is 4-20.

9. The battery pack as described in claim 5, characterized in that, The third isolation layer (330) is disposed on the side of the second isolation layer (320) away from the first isolation layer (310), and the third isolation layer (330) is made of the same material as the first isolation layer (310).

10. The battery pack as claimed in claim 9, characterized in that, Along the height direction of the single cell (20), the third isolation layer (330) has the same height as the first isolation layer (310).

11. The battery pack as claimed in claim 1, characterized in that, Along the height direction of the single cell (20), at least one end face of the first isolation layer (310) and the second isolation layer (320) is flush.

12. The battery pack as claimed in claim 1, characterized in that, Along the height direction of the single cell (20), one end face of the first insulating layer (310) protrudes from the second insulating layer (320).

13. The battery pack as claimed in claim 12, characterized in that, The end face of the first isolation layer (310) protrudes from the second isolation layer (320) by a distance d4mm ranging from 0.6mm to 3mm.

14. The battery pack as claimed in claim 1, characterized in that, The single cell (20) includes a first surface (210) and a second surface (220) located at both ends in its height direction, and the explosion-proof valve (10) is disposed on the first surface (210). The protective component (30) is flush with or protrudes from the first surface (210) at one end in the height direction of the single cell (20).

15. The battery pack as claimed in claim 14, characterized in that, The protective component (30) includes a support (340) which overlaps and is fixed to a portion of the first surface (210). The support (340) is composed of the first isolation layer (310) and / or the second isolation layer (320).

16. The battery pack as claimed in claim 1, characterized in that, The second isolation layer (320) has the same length as the first isolation layer (310) and is fitted together.

17. The battery pack as claimed in claim 1, characterized in that, The second isolation layer (320) is provided in multiple spaces along the length direction of the first isolation layer (310).

18. The battery pack as claimed in claim 17, characterized in that, Each of the individual cells (20) has a corresponding second isolation layer (320), and the gap between adjacent second isolation layers (320) corresponds to the gap between two individual cells (20).

19. The battery pack as claimed in claim 1, characterized in that, The range of k1W / (m·K) is 0.5W / (m·K)-5W / (m·K), the range of k2W / (m·K) is 0.015W / (m·K)-0.03W / (m·K), the range of e1MPa is 0.1MPa-15MPa, the range of e2MPa is 1MPa-50MPa, the range of d1mm is 1mm-5mm, and the range of d2mm is 0.1mm-0.8mm.

20. The battery pack as claimed in claim 1, characterized in that, The first isolation layer (310) and the second isolation layer (320) are bonded together.

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