Battery pack and electric device

Abstract

The embodiment of the invention provides a battery pack and an electric device, and relates to the technical field of batteries. The battery pack comprises battery packs, a plurality of conductive parts, a box body and a heat exchange assembly, each battery pack comprises at least one battery pack, each battery pack comprises a plurality of batteries, each conductive part comprises at least one bending part and at least two connecting parts, a box main body of the box body is provided with a containing cavity, and a first partition beam is arranged in the containing cavity; the first partition beam extends in the second direction, the containing cavity is divided into at least two containing spaces, each containing space is provided with one battery pack, the heat exchange assembly comprises a plurality of heat exchange plates, the heat exchange plates are sequentially arranged at intervals in the first direction, and at least one battery pack is arranged between every two adjacent heat exchange plates. According to the battery pack and the electric device provided by the embodiment of the invention, when the battery pack vibrates, an open circuit problem does not occur, and the heat dissipation effect of the battery pack can be improved.

Description

Technical Field

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

[0002] For electric vehicles, battery pack safety is a crucial factor. To enhance battery pack safety, a compartmentalized design is employed to prevent thermal runaway in one compartment from causing a fire to spread throughout the entire battery pack.

[0003] In related technologies, the battery pack is divided into compartments using a first partition beam. To improve the space utilization of the battery pack, reinforcing beams are removed from each compartment, resulting in a weaker battery pack strength and the possibility of open circuits when the battery pack vibrates. Summary of the Invention

[0004] This application provides a battery pack and an electrical device to solve the problem of open circuits that occur when the battery pack vibrates.

[0005] In a first aspect, embodiments of this application provide a battery pack, comprising:

[0006] A battery pack, comprising multiple batteries, wherein the multiple batteries are stacked in a large-to-large-face manner, and the stacking direction of the multiple batteries is a first direction;

[0007] Multiple conductive components, each conductive component including at least one bent portion and at least two connecting portions, wherein the bent portion is connected to one connecting portion at each end in the first direction, the bent portion is disposed between two adjacent batteries, and is electrically connected to the battery through the connecting portions;

[0008] The enclosure includes a main body and at least one first partition beam. The main body includes a bottom plate and a frame. The frame is disposed on the bottom plate and forms a receiving cavity. The first partition beam is disposed in the receiving cavity and extends along a second direction, dividing the receiving cavity into at least two receiving spaces. The receiving spaces are used to house the battery pack.

[0009] A heat exchange assembly is disposed between two adjacent batteries and extends along the second direction;

[0010] The direction perpendicular to the base plate is defined as the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other;

[0011] The dimension of the connection between the conductive component and the battery in the third direction is d1. In the second direction, the ratio of the dimension of the bent portion to the dimension of the conductive component is a1. The dimension of the first partition beam in the first direction is D1. The dimension of the heat exchange assembly in the first direction is D2.

[0012] The following conditions are met: d1, a1, D1, and D2 satisfy:

[0013] 0.004×10 -3 ≤(a1×d1) / (D1+D2)≤1.7×10 -3 Wherein, the units of d1, D1 and D2 are all mm.

[0014] Secondly, embodiments of this application provide an electrical device including the battery pack described in the first aspect.

[0015] This application provides a battery pack and an electrical device. If (a1×d1) / (D1+D2) is less than 0.004×10 -3 In some cases, the conductive component may be too small in the first direction, and / or the ratio of the bending portion to the conductive component in the second direction may be too small. This leads to an imbalance in the strength of the battery pack in the first and second directions. Consequently, under stress, the conductive component may easily break in the first direction due to insufficient strength, causing a circuit breakage problem when the battery pack vibrates. If (a1×d1) / (D1+D2) is greater than 1.7×10 -3 In this case, the ratio of the bend size to the conductive component size may be too large in the second direction, and / or the sum of the sizes of the various heat exchange plates in the first direction may be too small, resulting in poor heat dissipation of the battery pack. This can be addressed by ensuring that (a1×d1) / (D1+D2) is greater than or equal to 0.004×10⁻⁶. -3 And less than or equal to 1.7 × 10 -3 This design ensures that the battery pack has balanced strength in both the first and second directions. During stress, the conductive components will not break due to insufficient strength in the first direction, thus preventing open circuits when the battery pack vibrates. It also ensures the contact area between the battery and the heat exchange components, improving the heat dissipation effect of the battery pack. Attached Figure Description

[0016] 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a battery pack provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of a battery provided in an embodiment of this application;

[0019] Figure 3 for Figure 1 Enlarged view of point A in the middle;

[0020] Figure 4 This is a schematic diagram of the structure of a conductive element provided in an embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the structure of a box provided in an embodiment of this application;

[0022] Figure 6 A schematic diagram showing the connection of a housing, a battery pack, and a heat exchange plate provided in an embodiment of this application;

[0023] Figure 7 A schematic diagram showing the relative positions of a first partition beam, a battery, a heat exchange plate, and a conductive component, provided for an embodiment of this application;

[0024] Figure 8 This is a schematic diagram of the solder joint between a battery and a conductive component, provided as an embodiment of this application.

[0025] Figure 9 Another connection diagram of the housing, battery pack, and heat exchange plate provided for an embodiment of this application;

[0026] Figure 10 A schematic diagram of a heat exchange plate provided in an embodiment of this application;

[0027] Figure 11 A schematic diagram of another heat exchange plate provided in an embodiment of this application;

[0028] Figure 12 A schematic diagram showing the relative positions of another first partition beam, battery, heat exchange plate, and conductive component provided in an embodiment of this application;

[0029] Figure 13 This is a partial schematic diagram of the structure of another battery pack provided in an embodiment of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 10-Battery pack; 100-Battery; 101-First surface; 102-Second surface; 103-Terminal post; 104-Solder mark; 20-Conductive component; 201-Bending part; 202-Connecting part; 30-Box; 301-Accommodation space; 302-Electrical compartment; 31-Base plate; 32-Frame; 33-First partition beam; 34-Second partition beam; 40-Heat exchange plate; 401-Liquid inlet; 402-Liquid outlet; 50-Reinforcing component. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] In the above description, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] In related technologies, battery pack vibration can cause open circuit problems. Research has found that after removing the reinforcing beams in each compartment, the battery pack is weaker in its width direction, making conductive components prone to breakage, which can lead to open circuit problems when the battery pack vibrates.

[0038] To address the aforementioned issues, this application provides a battery pack and an electrical device. By limiting the thickness of the conductive component, the ratio of the dimension of the bent portion in its extension direction to the dimension of the conductive component in its extension direction, the dimension of the first partition beam in the first direction, and the sum of the dimensions of each heat exchange plate in the first direction, the conductive component is less prone to breakage, and no open circuit problem occurs when the battery pack vibrates.

[0039] The battery pack and power-consuming device provided in this application will be described in detail below with reference to specific embodiments.

[0040] First, see Figure 1 The length direction of the battery pack is defined as the X direction, i.e., the second X direction; the width direction of the battery pack is defined as the Y direction, i.e., the first Y direction; and the thickness direction of the battery pack is defined as the Z direction, i.e., the third Z direction. The second, first, and third directions are perpendicular to each other.

[0041] In a first aspect, embodiments of this application provide a battery pack, including a battery group 10.

[0042] There are multiple battery packs 10.

[0043] See Figure 1 and Figure 2 The battery pack 10 includes multiple batteries 100, which are stacked in a large-face-to-large-face configuration, with the stacking direction of the batteries 100 being the first direction. It should be noted that the largest surface area among all the surfaces of the battery 100 is the large-face surface of the battery 100.

[0044] The battery 100 can store chemical energy and controllably convert chemical energy into electrical energy. In the recyclable battery 100, the active materials can be activated by charging after discharge so that it can continue to be used.

[0045] The battery 100 includes a casing and battery cells disposed within the casing.

[0046] See in some examples Figure 2 The battery 100 has a first surface 101 in the second direction and a second surface 102 in the first direction. The area of ​​the second surface 102 is larger than the area of ​​the first surface 101, and the second surface 102 is the larger surface of the battery 100. The heat exchange plate 40 is in contact with the second surface 102.

[0047] See Figure 3 The battery pack also includes multiple conductive components 20. The conductive components 20 may be made of materials such as copper or gold.

[0048] The conductive element 20 is used to electrically connect multiple battery packs 10, thereby realizing the series connection and / or parallel connection of the multiple battery packs 10, that is, to realize the series connection of multiple battery packs 10, or to realize the parallel connection of multiple battery packs 10, or to realize the series connection and parallel connection of multiple battery packs 10.

[0049] Multiple batteries 100 in each battery pack 10 are connected in series via a conductive element 20.

[0050] The conductive element 20 can also electrically connect the output terminal of the battery pack 10 to the output terminal of the battery bag.

[0051] See Figure 4 Each conductive element 20 includes at least one bent portion 201 and at least two connecting portions 202. Each bent portion 201 is connected to a connecting portion 202 at both ends. The bent portion 201 is disposed between two adjacent batteries 100, and the connecting portion 202 is electrically connected to the battery 100.

[0052] See Figure 5 The battery pack also includes a housing 30. The housing 30 is a closed or semi-closed structure. The housing 30 is the physical carrier of the battery pack 10, and its design and manufacturing must meet the safety, reliability, and functionality requirements of the battery pack under different usage scenarios.

[0053] The enclosure 30 provides installation space for the battery pack 10, the battery management system (BMS), the cooling system, and the electrical connections 202. The battery pack 10, BMS, cooling system, and electrical connections 202 are secured within the enclosure 30, ensuring that they maintain a relatively stable position during battery pack operation and preventing damage or loosening of components due to vibration, impact, or other factors.

[0054] The housing 30 has a receiving cavity. A first partition beam 33 is disposed in the receiving cavity and extends along a second direction, dividing the receiving cavity into at least two receiving spaces 301, each receiving space 301 housing the battery pack 10.

[0055] The number of battery packs 10 in each compartment 301 can be one or more.

[0056] In this embodiment, the receiving cavity is divided into two receiving spaces 301. Each receiving space 301 contains a plurality of battery packs 10, which are arranged along a second direction.

[0057] The box body 30 includes a main body and at least one first partition beam 33. The main body includes a base plate 31 and a surrounding frame 32, with the surrounding frame 32 mounted on the base plate 31. The direction perpendicular to the base plate 31 is defined as the third direction.

[0058] The main body of the box also includes a cover plate, which is connected to the frame 32. The cover plate and the bottom plate 31 are arranged opposite to each other, and the bottom plate 31, the frame 32 and the cover plate together enclose and form a receiving cavity.

[0059] The housing 30 can be cast from materials such as steel plate or aluminum alloy. In other embodiments, the housing 30 can also be made of lightweight materials, such as glass fiber reinforced composite materials or carbon fiber reinforced composite materials.

[0060] The battery pack also includes a heat exchange assembly. The heat exchange assembly is disposed between two adjacent batteries 100 and extends along a second direction. The heat exchange assembly is used to dissipate heat from the batteries 100 to regulate the temperature of the batteries 100.

[0061] The heat exchange assembly includes multiple heat exchange plates 40, which are arranged sequentially at intervals along a first direction. In the first direction, the heat exchange plates 40 are disposed between two adjacent batteries 100.

[0062] The heat exchange plate 40 can contain refrigerant, which cools the battery 100 through phase change. The refrigerant can be a gas, solid, or liquid. For example, a liquid with a higher specific heat capacity than water can be used as the coolant to achieve liquid cooling of the battery 100.

[0063] The heat exchange plate 40 is made of materials including but not limited to copper, iron, aluminum, stainless steel or aluminum alloy.

[0064] The dimension of the connection point between the conductive element 20 and the battery 100 in the third direction is d1 (see [reference]). Figure 4 Specifically, the dimension of the connection portion 202 of the conductive member 20 in the third direction of the connection point with the battery 100 is d1.

[0065] In the second direction, the ratio of the size of the bent portion 201 to the size of the conductive element 20 is a1.

[0066] In the first direction, the dimension of the first partition beam 33 is D1 (see...) Figure 5 ).

[0067] In the first direction, the size of the heat exchange assembly is D2, that is, the sum of the sizes of all heat exchange plates 40 in the first direction in all accommodating spaces 301 is D2.

[0068] d1, a1, D1, and D2 satisfy:

[0069] 0.004×10 -3 ≤(a1×d1) / (D1+D2)≤1.7×10 -3 Where d1, D1, and D2 are all in mm. For example, (a1×d1) / (D1+D2) can take the value 0.004×10 -3 0.005×10 -3 0.01×10 -3 0.05×10 -3 0.1×10 -3 0.5×10 -3 1×10 -3 Or 1.7×10 -3 wait.

[0070] If (a1×d1) / (D1+D2) is less than 0.004×10 -3 In some cases, the conductive component 20 may be too small in the third direction, and / or the ratio of the size of the bent portion to the size of the conductive component may be too small in the second direction. This results in an imbalance of strength between the battery pack in the first and second directions. Consequently, during stress, the conductive component may easily break in the first direction due to insufficient strength, leading to a circuit breakage problem when the battery pack vibrates. If (a1×d1) / (D1+D2) is greater than 1.7×10 -3 In this case, the ratio of the size of the bend to the size of the conductive component may be too large in the second direction, and / or the sum of the sizes of the various heat exchange plates 40 in the first direction may be too small, resulting in poor heat dissipation of the battery pack. This can be addressed by ensuring that (a1×d1) / (D1+D2) is greater than or equal to 0.004×10⁻⁶.-3 And less than or equal to 1.7 × 10 -3 This design ensures that the battery pack has balanced strength in both the first and second directions. During stress, the conductive components will not break due to insufficient strength in the first direction, thus preventing open circuits when the battery pack vibrates. It also ensures the contact area between the battery and the heat exchange components, improving the heat dissipation effect of the battery pack.

[0071] In one possible implementation, each containing space 301 is sealed. This arrangement prevents the individual battery packs 10 from interfering with each other, ensuring that even if one battery pack 10 experiences thermal runaway, the other battery packs 10 can continue to operate.

[0072] In this case, sealing gaskets are provided between the cover plate of the box body 30 and the first partition beam 33, and between the cover plate and the frame 32. The cover plate is fixed to the frame 32 by bolts, and the sealing gaskets are compressed to achieve separate sealing of each accommodating space 301.

[0073] The sealing gasket material can be selected from materials such as silicone, fluororubber, soluble polytetrafluoroethylene, or polytetrafluoroethylene.

[0074] The battery packs 10 within each housing space 301 are connected in series and / or in parallel via conductive elements 20. Specifically, the battery packs 10 within each housing space 301 are connected in series via conductive elements 20. Alternatively, the battery packs 10 within each housing space 301 are connected in parallel via conductive elements 20. Or, the battery packs 10 within each housing space 301 are connected in both series and parallel via conductive elements 20, i.e., there are both parallel and series circuits, and the choice between parallel and series connection can be made according to the usage conditions.

[0075] In some examples, the battery packs 10 within each housing space 301 are connected in series and parallel via conductive elements 20. When high-voltage transmission is required to increase the charge / discharge rate of the battery 100, the battery packs 10 are connected in series. When there is a safety risk with one battery pack 10 or only one battery pack 10 needs to be charged and discharged, the circuit switches to parallel connection.

[0076] In one possible implementation, see Figure 5 The enclosure 30 also includes a second partition beam 34, which is disposed inside the enclosure 30 and connected to one end of the first partition beam 33. The second partition beam 34 divides the interior of the enclosure 30 into an electrical compartment 302 and a receiving cavity. The electrical compartment 302 and the receiving cavity are independently sealed, and adjacent receiving spaces 301 are also independently sealed. This arrangement isolates the electrical compartment 302 from the receiving cavity and adjacent receiving spaces 301, preventing the spread of thermal runaway.

[0077] In one possible implementation, see Figure 6 In the first direction, the minimum distance between the heat exchange plate 40 and the first partition beam 33 is L10. L10 satisfies: L10≥1mm. For example, L10 can take values ​​of 1mm, 2mm, 2.5mm or 3mm, etc.

[0078] If L10 is less than 1mm, the heat exchange plate 40 will transfer heat through the first partition beam 33, causing adjacent battery packs 10 to interfere with each other. By limiting the minimum distance between the heat exchange plate 40 and the first partition beam 33 in the first direction, the mutual interference between adjacent battery packs 10 can be avoided.

[0079] In one possible implementation, see Figure 6 In the first direction, the minimum distance between two adjacent heat exchange plates 40 in the accommodating spaces 301 is L11. L11 satisfies: L11≥4mm. For example, L11 can take values ​​of 4mm, 5mm, 5.5mm or 6mm, etc.

[0080] If L11 is less than 4mm, the heat exchange plates 40 in two adjacent housing spaces 301 will be too close together in the first direction, causing the heat exchange plates 40 to transfer heat through the first partition beam 33, resulting in the two adjacent battery packs 10 affecting each other. By limiting the minimum distance between the heat exchange plates 40 in two adjacent housing spaces 301 in the first direction, the mutual interference between the two adjacent battery packs 10 can be avoided.

[0081] In one possible implementation, a1 satisfies: 0.04 ≤ a1 ≤ 0.5. For example, a1 can take values ​​of 0.04, 0.1, 0.2, 0.3, 0.4, or 0.5, etc.

[0082] If a1 is less than 0.04, the reinforcing effect of the bend 201 on the conductive component 20 will be poor, making the conductive component 20 prone to breakage and causing an open circuit problem when the battery pack vibrates. If a1 is greater than 0.5, the internal resistance of the conductive component 20 will be high, resulting in greater heat generation and poor heat dissipation of the battery 100 heat sink. By ensuring a1 is greater than or equal to 0.04 and less than or equal to 0.5, the conductive component 20 is less prone to breakage, preventing open circuit problems when the battery pack vibrates and improving the heat dissipation effect of the battery pack.

[0083] In the first direction, the dimension of the bent portion 201 is greater than or equal to 5 mm and less than or equal to 40 mm. For example, in the second direction, the dimension of the bent portion 201 can be 5 mm, 10 mm, 20 mm, 30 mm, or 10 mm, etc.

[0084] In the first direction, the dimension of the conductive element 20 is greater than or equal to 50 mm and less than or equal to 160 mm. For example, in the second direction, the dimension of the conductive element 20 can be 50 mm, 60 mm, 80 mm, 100 mm, 150 mm, or 160 mm, etc.

[0085] In one possible implementation, see Figure 7 The battery 100 includes a terminal post 103, which is welded to a conductive element 20. In a first direction, the end of the conductive element 20 extends beyond the terminal post 103 by a dimension L1, which satisfies the condition: 1mm ≤ L1 ≤ 5mm. For example, L1 can be 1mm, 1.5mm, 2mm, 3mm, 4mm, or 5mm, etc.

[0086] If L1 is less than 1mm, the conductive component 20 may easily disconnect from the terminal 103 when the battery pack vibrates, causing an open circuit in the battery pack. If L1 is greater than 5mm, the conductive component 20 may easily come into contact with other metal components, leading to a short circuit in the battery pack. By ensuring that L1 is greater than or equal to 1mm and less than or equal to 5mm, both open circuits and short circuits in the battery pack can be avoided.

[0087] In one possible implementation, in a first direction, a plurality of conductive elements 20 are arranged sequentially at intervals, with the interval between two adjacent conductive elements 20 being L2 (see [link]). Figure 3 L2 satisfies: 2mm≤L2≤20mm. For example, L2 can take values ​​of 2mm, 3mm, 5mm, 10mm, 15mm, or 20mm, etc.

[0088] If L2 is less than 2mm, adjacent conductive parts 20 may easily overlap, leading to a short circuit in the battery pack. If L2 is greater than 20mm, the battery pack will be weaker in the first direction, making the conductive parts 20 prone to breakage, resulting in an open circuit when the battery pack vibrates. By ensuring L2 is greater than or equal to 2mm and less than or equal to 20mm, both open and short circuits in the battery pack can be avoided.

[0089] In one possible implementation, in the second direction, a plurality of conductive elements 20 are arranged sequentially at intervals, with the interval between two adjacent conductive elements 20 being L5 (see [link]). Figure 3 L5 satisfies: 10mm≤L5≤260mm. For example, L5 can take values ​​of 10mm, 20mm, 50mm, 100mm, 150mm, 200mm, or 260mm, etc.

[0090] If L5 is less than 10mm, adjacent conductive parts 20 may easily overlap, leading to a short circuit in the battery pack. If L5 is greater than 260mm, the conductive parts are too narrow and weak, resulting in lower strength of the battery pack in the first direction. This makes the conductive parts 20 prone to breakage, causing open circuits when the battery pack vibrates. By ensuring L5 is greater than or equal to 10mm and less than or equal to 260mm, both open and short circuits in the battery pack can be avoided.

[0091] In one possible implementation, the battery 100 includes a terminal post 103, the terminal post 103 being provided with a welding area, and a connecting portion 202 being welded to the welding area. In a first direction, the minimum distance between the bent portion 201 and the welding area is L3 (see [reference]). Figure 3 L3 satisfies: 2mm≤L3≤10mm. For example, L3 can take values ​​of 2mm, 3mm, 5mm, 8mm, 9mm, or 10mm, etc.

[0092] If L3 is less than 2mm, the bend 201 will be too close to the welding area, causing stress concentration after the conductive component 20 is welded to the terminal post 103. This makes the conductive component 20 prone to breakage, leading to an open circuit problem when the battery pack vibrates. If L3 is greater than 10mm, the reinforcement effect of the bend 201 on the conductive component 20 will be poor, making the conductive component 20 prone to breakage and causing an open circuit problem when the battery pack vibrates. By ensuring that L3 is greater than or equal to 2mm and less than or equal to 10mm, the conductive component 20 is less likely to break, and an open circuit problem will not occur when the battery pack vibrates.

[0093] In one possible implementation, in the second direction, the ratio of the size of the bent portion 201 to the size of the conductive element 20 is a2, where a2 satisfies: a2 ≥ 0.8. For example, a2 can take values ​​of 0.8, 1, 2, or 5, etc.

[0094] If a2 is less than 0.8, the reinforcing effect of the bend 201 on the conductive component 20 will be poor, making the conductive component 20 prone to breakage and causing an open circuit problem when the battery pack vibrates. By making a2 greater than or equal to 0.8, the conductive component 20 is less likely to break, and an open circuit problem will not occur when the battery pack vibrates.

[0095] In one possible implementation, in the second direction, a plurality of conductive elements 20 are arranged sequentially at intervals, and the sum of the dimensions of each conductive element 20 is D3, where D1, D2, and D3 satisfy: 0.96 ≤ D3 / (D1+D2) ≤ 9.5, where the units of D1, D2, and D3 are all mm. For example, D3 / (D1+D2) can take values ​​of 0.96, 1, 2, 5, 9, or 9.5, etc.

[0096] If D3 / (D1+D2) is less than 0.96, the battery pack will be weak in the first direction, making the conductive component 20 prone to breakage. This can lead to an open circuit when the battery pack vibrates. If D3 / (D1+D2) is greater than 9.5, adjacent conductive components 20 may easily overlap, causing a short circuit in the battery pack. By ensuring that D3 / (D1+D2) is greater than or equal to 0.96 and less than or equal to 9.5, it is possible to avoid open circuits caused by conductive component breakage and to prevent short circuits caused by conductive components being too close together.

[0097] Wherein, D3 satisfies: 250mm≤D3≤840mm. For example, D3 can take values ​​of 250mm, 300mm, 500mm, 600mm, 800mm, or 840mm, etc.

[0098] D1 and D2 satisfy the condition: 80mm ≤ D1 + D2 ≤ 260mm. For example, D1 + D2 can take values ​​of 80mm, 100mm, 150mm, 200mm, 250mm, or 260mm, etc.

[0099] In one possible implementation, d1 satisfies: 0.8mm ≤ d1 ≤ 2.5mm. For example, d1 can take values ​​of 0.8mm, 1mm, 1.1mm, 1.5mm, 2mm, or 2.5mm, etc.

[0100] If d1 is less than 0.8 mm, the connection between the conductive component 20 and the battery 100 will be weak, making the conductive component 20 prone to cracking at the connection point, resulting in an open circuit when the battery pack vibrates. If d1 is greater than 2.5 mm, the conductive component 20 will occupy a large amount of space in the third direction, leading to a decrease in the energy density of the battery pack. By ensuring that d1 is greater than or equal to 0.8 mm and less than or equal to 2.5 mm, open circuits in the battery pack can be avoided, and the energy density of the battery pack can be improved.

[0101] In one possible implementation, see Figure 7 The dimension of the bent portion 201 in the third direction is d2, and d1 and d2 satisfy: 0.2≤d1 / d2≤1.6. For example, d1 / d2 can take values ​​of 0.2, 0.5, 1, 1.5 or 1.6, etc.

[0102] If d1 / d2 is less than 0.2, the bending section 201 will be too thin, resulting in a high internal resistance of the conductive component 20, causing it to overheat and leading to poor heat dissipation in the battery 100 heat sink. If d1 / d2 is greater than 1.6, the bending section 201 will be too thick, making the conductive component 20 prone to stress concentration and breakage, potentially causing an open circuit when the battery pack vibrates. Maintaining a d1 / d2 ratio greater than or equal to 0.2 and less than or equal to 1.6 improves the battery pack's heat dissipation and prevents open circuits.

[0103] Wherein, d2 satisfies: 1.5mm ≤ d2 ≤ 5mm. For example, d2 can take values ​​of 1.5mm, 2mm, 3mm, 4mm, or 5mm, etc.

[0104] In one possible implementation, the battery 100 is welded to the conductive component 20. The length direction of the solder joint 104 is parallel to the second direction, and the width direction of the solder joint 104 is parallel to the first direction. The ratio a3 of the dimension of the solder joint 104 in the second direction to the dimension of the solder joint 104 in the first direction satisfies: 1.1 ≤ a3 ≤ 4.2. For example, a3 can take values ​​of 1.1, 1.5, 2, 3, 4, or 4.2, etc.

[0105] If a3 is less than 1.1, the size of the solder mark 104 in the second direction is too small, causing the conductive component 20 to easily peel off from the battery 100 when subjected to force in the first direction. If a3 is greater than 4.2, the size of the solder mark 104 in the second direction is too large, making it easy to damage the casing of the battery 100 during the welding process between the conductive component 20 and the battery 100. By ensuring that a3 is greater than or equal to 1.1 and less than or equal to 4.2, it is possible to prevent the conductive component 20 from easily peeling off from the battery 100 when subjected to force in the first direction, and also to prevent damage to the casing of the battery 100 during the welding process between the conductive component 20 and the battery 100.

[0106] Among them, see Figure 8 The dimension of solder mark 104 in the second direction is b1. The dimension of solder mark 104 in the first direction is b2.

[0107] In one possible implementation, in the second direction, the end of the heat exchange plate 40 extends beyond the end of the battery pack 10 by an amount of L7 (see [reference]). Figure 6 L7 satisfies: 20mm≤L7≤50mm. For example, L7 can take values ​​of 20mm, 25mm, 30mm, 35mm, 40mm, or 50mm, etc.

[0108] If L7 is less than 20mm, the heat exchange plate 40 will be too small in the second direction, resulting in poor heat dissipation of the battery pack. If L7 is greater than 50mm, the heat exchange plate 40 will be too large in the second direction, causing excessive strength of the battery pack and resulting in poor overall strength uniformity. By setting L7 to be greater than or equal to 20mm and less than or equal to 50mm, the overall strength uniformity of the battery pack can be improved, as can its heat dissipation effect.

[0109] In one possible implementation, the conductive element 20 has a dimension of L4 in the first direction (see...). Figure 3L4 satisfies: 50mm≤L4≤160mm. For example, L4 can take values ​​of 50mm, 80mm, 100mm, 150mm, or 160mm, etc.

[0110] If L4 is less than 50mm, the conductive component 20 will be too small in the first direction, resulting in a weak connection between the conductive component 20 and the battery 100. This makes the conductive component 20 prone to breakage, leading to an open circuit when the battery pack vibrates. If L4 is greater than 160mm, the conductive component 20 will be too large in the first direction, causing adjacent conductive components 20 to easily overlap, resulting in a short circuit in the battery pack. By ensuring that L4 is greater than or equal to 50mm and less than or equal to 160mm, both open circuits and short circuits in the battery pack can be avoided.

[0111] The conductive element 20 has a dimension of L6 in the second direction (see...). Figure 6 L6 satisfies: 25mm≤L6≤60mm. For example, L6 can take values ​​of 25mm, 30mm, 34mm, 40mm, 50mm, 55mm, or 60mm, etc.

[0112] If L6 is less than 25 mm, the conductive component 20 will be too small in the second direction, resulting in a weak connection between the conductive component 20 and the battery 100. This makes the conductive component 20 prone to breakage, leading to an open circuit when the battery pack vibrates. If L6 is greater than 60 mm, the conductive component 20 will be too large in the second direction, causing adjacent conductive components 20 to easily overlap, resulting in a short circuit in the battery pack. By ensuring that L6 is greater than or equal to 25 mm and less than or equal to 60 mm, both open circuits and short circuits in the battery pack can be avoided.

[0113] In one possible implementation, see Figure 9 In the second direction, the end of the heat exchange plate 40 abuts against the housing 30. This arrangement can improve the reinforcing effect of the heat exchange plate 40 on the housing 30, thereby increasing the strength of the housing 30.

[0114] In this embodiment, d1 is greater than or equal to 1 mm and less than or equal to 2.5 mm.

[0115] In one possible implementation, in the second direction, the end of the heat exchange plate 40 is spaced apart from the housing 30, and the distance between the end of the heat exchange plate 40 and the housing 30 is L8 (see [reference]). Figure 6 L8 satisfies: 5mm≤L8≤100mm. This setting can prevent the force from being transferred to the heat exchange plate 40 when the housing 30 is under stress, thus avoiding damage to the battery 100. At the same time, it can also avoid the spacer size being too large, which would result in the heat exchange plate size being too small and affecting the heat exchange effect.

[0116] In some examples, in the second direction, the ratio of the size of the heat exchange plate 40 to the size of the first partition beam 33 is a4, where a4 satisfies: 0.6 ≤ a4 ≤ 1. For example, a4 can take values ​​of 0.6, 0.65, 0.7, 0.8, 0.9, or 1, etc.

[0117] If a4 is less than 0.6, the size of the heat exchange plate 40 is too small in the second direction, resulting in poor heat dissipation of the battery pack. If a4 is greater than 1, the size of the first partition beam 33 is too small in the second direction, leading to weak strength of the battery pack in the second direction, making the conductive component 20 prone to breakage and causing open circuit problems when the battery pack vibrates. By setting a4 greater than or equal to 0.4 and less than or equal to 1, the heat dissipation of the battery pack can be improved, making the conductive component 20 less prone to breakage and preventing open circuit problems when the battery pack vibrates.

[0118] In one possible implementation, D2 satisfies: 70mm ≤ D2 ≤ 210mm. For example, D2 can take values ​​of 70mm, 80mm, 90mm, 100mm, 150mm, 200mm, or 210mm, etc.

[0119] If D2 is less than 70mm, the heat exchange component will be weak and prone to breakage. If D2 is greater than 210mm, the heat exchange component will occupy a large space in the battery pack, resulting in low space utilization. A D2 between 70mm and 210mm is ideal, as it reduces the likelihood of breakage and improves battery pack space utilization.

[0120] In this embodiment, the dimension of a single heat exchange plate 40 in the first direction is L9 (see...). Figure 6 L9 satisfies: 3.5mm ≤ L9 ≤ 7mm. For example, L9 can take values ​​of 3.5mm, 4mm, 4.5mm, 5mm, 6mm, or 7mm, etc.

[0121] See in some examples Figure 10 The heat exchange plate 40 is provided with an inlet 401 and an outlet 402, which are located on the same side of the heat exchange plate 40 in the second direction. By arranging the inlet 401 and outlet 402 on the same side of the heat exchange plate 40 in the second direction, the space occupied by the heat exchange plate 40 in the second direction can be reduced, improving the space utilization of the battery pack and also improving the uniformity of heat dissipation. The dimension of the heat exchange plate 40 in the first direction is L9, and L9 satisfies: 4mm ≤ L9 ≤ 7mm. For example, L9 can be 4mm, 4.5mm, 5mm, 5.5mm, or 7mm, etc. In this example, the heat exchange plate is fixed at one end. To prevent displacement at the other end, the plate thickness is increased to improve its mass, thus preventing displacement.

[0122] See in some examples Figure 11 The heat exchange plate 40 is provided with an inlet 401 and an outlet 402, which are located on opposite sides of the heat exchange plate 40 in the second direction. The dimension of the heat exchange plate 40 in the first direction is L9. L9 satisfies: 3.5mm ≤ L9 ≤ 6mm. For example, L9 can be 3.5mm, 4.5mm, 5mm, 5.5mm, or 6mm. This arrangement, with the inlet 401 and outlet 402 located on opposite sides of the heat exchange plate 40 in the second direction, ensures balanced strength on both sides of the heat exchange plate 40 in the second direction, reduces the thickness of the heat exchange plate 40, and avoids excessive temperature differences between the battery 100 near the inlet 401 and the battery 100 near the outlet 402.

[0123] In some examples, a heat exchange plate 40 is provided between any two adjacent batteries 100 in the first direction, and the size of the heat exchange plate 40 is L9. L9 satisfies: 3.5mm≤L9≤5mm. This arrangement can improve heat dissipation efficiency and also avoid excessive strength of the battery pack in the second direction by reducing the thickness of the heat exchange plate 40.

[0124] In some examples, multiple batteries 100 are arranged between adjacent heat exchange plates 40 in the first direction, and the size of the heat exchange plate 40 is L9. L9 satisfies: 4mm≤L9≤7mm. This arrangement allows the battery pack to accommodate more batteries 100, thereby improving the space utilization and energy density of the battery pack.

[0125] In one possible implementation, in the third direction, the ratio of the size of the projection of the heat exchange plate 40 onto the large surface (second surface 102) of the battery 100 to the size of the battery 100 is a5. a5 satisfies: 0.6 ≤ a5 ≤ 1. For example, the value of a5 can be 0.6, 0.65, 0.7, 0.8, 0.9, or 1, etc.

[0126] If a5 is less than 0.6, there will be poor heat exchange capacity between the heat exchange plate 40 and the battery 100. If a5 is greater than 1, the strength of the battery pack in the second direction will be too high, resulting in insufficient strength in the first direction. This will make the conductive component 20 prone to breakage, causing an open circuit problem when the battery pack vibrates. By ensuring a5 is greater than or equal to 0.6 and less than or equal to 1, the heat exchange capacity between the heat exchange plate 40 and the battery 100 can be improved, and the open circuit problem of the battery pack can be avoided.

[0127] It should be noted that, see Figure 6 Multiple battery packs 10 are arranged within the accommodating space 301, and the multiple battery packs 10 are arranged along a second direction. In the second direction, adjacent batteries 100 exchange heat through a heat exchange plate 40.

[0128] In one possible implementation, D1 satisfies: 10mm ≤ D1 ≤ 50mm. For example, D1 can take values ​​of 10mm, 11mm, 15mm, 20mm, 30mm, 40mm, or 50mm, etc.

[0129] If D1 is less than 10mm, the first separator beam 33 will be weak, making it prone to breakage. If D1 is greater than 50mm, the first separator beam 33 will occupy a large space in the battery pack, resulting in low space utilization. A D1 between 10mm and 50mm makes the first separator less prone to breakage and also improves the space utilization of the battery pack.

[0130] In one possible implementation, the main body of the battery pack includes a base plate 31, a frame 32, and a cover plate. In the third direction, the base plate 31 is located at the bottom of the frame 32, and the cover plate is located at the top of the frame 32. The top of the partition beam is sealed to the cover plate. The distance between the top of the first partition beam 33 and the base plate 31 is greater than or equal to the distance between the top of the conductive element 20 and the base plate 31. This arrangement can improve the strength of the battery pack in the second direction and also prevent the cover plate at the top of the battery pack 30 from overlapping with the conductive element 20 and causing insulation failure.

[0131] The cover plate is sealed to the first partition beam 33.

[0132] In some examples, on the third-order side, the top of the first partition beam 33 is higher than the top of the conductive element 20, and the distance between the top of the first partition beam 33 and the top of the conductive element 20 is L12 (see [reference]). Figure 7 L12 satisfies: 0.5mm ≤ L12 ≤ 5mm. For example, L12 can take values ​​of 0.5mm, 1mm, 2mm, 3mm, 4mm, or 5mm, etc.

[0133] If L12 is less than 0.5mm, in the third direction, the distance between the top of the first partition beam 33 and the top of the conductive component 20 will be too small. When the battery 100 experiences thermal runaway within the housing space 301, the generated high-temperature gas will accumulate at the top of the housing space 301. The top of the first partition beam 33 will be easily affected by the thermal runaway gas, leading to the failure of the seal of both housing spaces 301. If L12 is greater than 5mm, in the third direction, the distance between the top of the first partition beam 33 and the top of the conductive component 20 will be too large, resulting in poor space utilization of the battery pack in its height direction. By setting L12 to be greater than or equal to 0.5mm and less than or equal to 5mm, the seal of both housing spaces 301 can be guaranteed, and the space of the battery pack in its height direction can be fully utilized.

[0134] In one possible implementation, see Figure 12In the third direction, the top of the first partition beam 33 is lower than the top of the conductive element 20, and the distance between the top of the first partition beam 33 and the top of the conductive element 20 is L13. L13 satisfies: 2mm ≤ L13 ≤ 8mm. For example, L13 can take values ​​of 2mm, 2.5mm, 3mm, 4mm, 6mm, or 8mm, etc.

[0135] If L13 is less than 2mm, in the third direction, the distance between the top of the first partition beam 33 and the top of the conductive component 20 will be too small. When the battery 100 experiences thermal runaway within the housing space 301, the generated high-temperature gas will accumulate at the top of the housing space. The top of the first partition beam 33 will be easily affected by the thermal runaway gas, leading to sealing failure of both housing spaces 301. If L13 is greater than 8mm, in the third direction, the distance between the top of the first partition beam 33 and the top of the conductive component 20 will be too large, resulting in insufficient strength of the battery pack in the first direction. This can cause open circuit problems when the battery pack vibrates. By ensuring that L13 is greater than or equal to 2mm and less than or equal to 8mm, the sealing of both housing spaces 301 can be guaranteed, and open circuit problems can be prevented when the battery pack vibrates.

[0136] In one possible implementation, battery packs 10 are disposed in both adjacent housing spaces 301. The positive electrode material of the battery 100 in at least one housing space 301 is lithium nickel cobalt manganese oxide.

[0137] Among them, lithium nickel cobalt manganese oxide satisfies the general formula LiNi b Co c Mn d M1 e 02.

[0138] The general formula satisfies: 0 <b<1,0<c<1,0<d<l,b+c+d+e=l,0≤e≤0.2。

[0139] M1 is at least one of B, Br, Ti, Si, Mo, La, Ce, Te, Nb, Ta, Si, Al, W, Sr, V, Y, Mg, and Co.

[0140] In one possible implementation, the capacity of battery 100 is greater than or equal to 150 Ah and less than or equal to 600 Ah. For example, the capacity of battery 100 can be 150 Ah, 200 Ah, 300 Ah, 400 Ah, 500 Ah, or 600 Ah. Having a capacity of 150 Ah or greater ensures that the number of batteries in a battery pack of the same capacity is not excessive, thus preventing complex integration processes and ensuring integration efficiency. Simultaneously, limiting the capacity of battery 100 to no more than 600 Ah reduces the release of high-temperature gases during thermal runaway of individual cells, preventing these gases from entering other containment spaces and affecting the safety of the battery pack.

[0141] In this embodiment, D2 satisfies: 100mm≤D2≤210mm.

[0142] In one possible implementation, see Figure 13 At least one accommodating space 301 is provided with a reinforcing member 50, which extends along a first direction and covers at least two batteries 100 along the first direction. The overlapping area of ​​the reinforcing member 50 and the batteries 100 is S1, and the surface area of ​​the battery 100 on the side where the reinforcing member 50 is located is S2. The ratio of S1 to S2 is greater than or equal to 0.01 and less than or equal to 0.1. For example, the ratio of S1 to S2 can take values ​​such as 0.01, 0.03, 0.05, 0.06, 0.09, or 0.1.

[0143] If the ratio of S1 to S2 is less than 0.01, the overlap area between the reinforcing member 50 and the battery 100 will be too small, resulting in poor reinforcement of the battery pack by the reinforcing member 50. This makes the conductive member 20 prone to breakage, leading to an open circuit problem when the battery pack vibrates. If the ratio of S1 to S2 is greater than 0.1, the overlap area between the reinforcing member 50 and the battery 100 will be too large, resulting in poor heat dissipation of the battery pack. By ensuring that the ratio of S1 to S2 is greater than or equal to 0.01 and less than or equal to 0.1, the conductive member 20 is less likely to break. When the battery pack vibrates, the strength of the battery pack in the first direction is increased, preventing the conductive member from breaking and avoiding an open circuit problem, while not affecting the heat dissipation of the battery 100.

[0144] In the second direction, two adjacent battery packs 10 are connected by a reinforcing member 50. This arrangement allows multiple battery packs 10 to be connected into a whole, improving the overall strength, making the conductive member 20 less prone to breakage, and preventing open circuit problems when the battery pack vibrates.

[0145] The material of the reinforcing component 50 can be any one or a combination of several of epoxy resin, phenolic resin, modified epoxy resin, polyester resin, polyurethane resin and glass fiber, with a commonly used material being a mixture of polyester resin and glass fiber.

[0146] Secondly, embodiments of this application provide an electrical device including the battery pack of the first aspect.

[0147] The electrical device in this embodiment includes the battery pack described in the previous embodiment, which makes the conductive component 20 less prone to breakage, prevents open circuit problems when the battery pack vibrates, and improves the heat dissipation effect of the battery pack.

[0148] The battery 100 device can be used as an operating power source for electrical devices, or as a driving power source for electrical devices, replacing or partially replacing fuel or natural gas to provide driving power for vehicles.

[0149] Electrical devices include energy storage equipment, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, electric cars, military equipment, and devices in the aerospace field.

[0150] The battery pack provided in this application will be described in detail below through specific embodiments.

[0151] Method for preparing battery 100:

[0152] (1) Preparation of positive electrode sheet

[0153] The prepared positive electrode active material, conductive agent (e.g., acetylene black), and binder (e.g., PVDF) are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the positive electrode sheet is obtained.

[0154] Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies the following: (92~98): (4~1): (4~1).

[0155] (2) Preparation of negative electrode sheet

[0156] The negative electrode active material, conductive agent (e.g., acetylene black), thickener (e.g., carboxymethyl cellulose (CMC)), and binder (e.g., styrene-butadiene rubber (SBR)) are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained.

[0157] Specifically, the ratio of negative electrode active material: conductive agent: thickener: binder satisfies the following: (90~96): (4~2): (2~1): (4~1).

[0158] (3) Preparation of electrolyte:

[0159] Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1~2.5 mol / L.

[0160] (4) Preparation of the separating membrane:

[0161] Polyethylene film was selected as the separator.

[0162] (5) Preparation of lithium-ion batteries:

[0163] The above-mentioned positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and then wound or stacked to obtain a bare cell. The bare cell is placed in an outer packaging shell, dried, injected with electrolyte, and then packaged, left to stand, formed, and calibrated to obtain a lithium-ion battery.

[0164] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt and manganese, and lithium manganese iron phosphate.

[0165] The negative electrode active material can be selected from one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0166] If (a1×d1) / (D1+D2) is too small, the conductive component 20 is prone to breakage. The test method is as follows:

[0167] For each embodiment and comparative example, 200 identical batteries 100 are taken. These 100 batteries 100 are treated as a whole, and then grouped into 10 battery packs 10 of 10 batteries 100 each. In each battery pack 10, adjacent batteries 100 are stacked with their large surfaces facing each other. The 100 batteries 100 are connected in series using a conductive element 20. The 10 battery packs 10 are placed on the bottom plate 31 of a receiving space 301 in the housing 30. Another 100 batteries 100 are also grouped into 10 battery packs 10 of 10 each, with adjacent batteries 100 in each battery pack 10 stacked with their large surfaces facing each other. 100 batteries 100 are stacked in rows and connected in series with conductive components 20. Ten battery packs 10 are placed on the bottom plate 31 of another accommodating space 301 of the housing 30. The two accommodating spaces 301 are separated by a first partition beam 33. The large surface of the battery 100 in the battery pack 10 is parallel to the length direction of the first partition beam 33 (the length direction is parallel to the plane where the bottom plate 31 is located), and the length direction of the battery pack 10 is also parallel to the length direction of the first partition beam 33. A heat exchange component is set between adjacent batteries 100 along the stacking direction of the battery 100 in the battery pack 10 (the stacking direction of the battery 100 in the battery pack 10 is parallel to the plane where the bottom plate 31 is located).

[0168] The length direction of the first separator beam 33 is the second direction. The stacking direction of the batteries 100 in the battery pack 10 is the first direction.

[0169] The dimension of the connection between the conductive element 20 and the battery 100 in the third direction is d1. In the second direction, the ratio of the dimension of the bent portion 201 of the conductive element 20 to the dimension of the conductive element 20 is a1. The dimension of the first partition beam 33 in the first direction is D1. The dimension of the heat exchange assembly in the first direction is D2. Except for the parameters in Table 1, the structures of the rest of the battery pack are the same.

[0170] The battery pack was placed in a vibration table and subjected to random vibration in the Z / Y / X directions and sinusoidal fixed-frequency vibration under the conditions of GB38031-2020.8.2. The random vibration in each direction was carried out for 12 hours and the sinusoidal fixed-frequency vibration for 2 hours. The cracking phenomenon of conductive component 20 was observed. The fracture rate of conductive component 20 was calculated according to the formula: (number of cracked conductive components 20 / total number of conductive components 20) × 100%. If the fracture rate of conductive component 20 was greater than 2%, it was unqualified; otherwise, it was qualified.

[0171] If (a1×d1) / (D1+D2) is too large, the heat dissipation of the battery pack will be poor. The test method is as follows:

[0172] For each embodiment and comparative example, 100 identical batteries 100 are taken. 50 batteries 100 are treated as a whole, and then grouped into 5 battery packs 10 of 10. In each battery pack 10, adjacent batteries 100 are stacked with their large surfaces facing each other. The 50 batteries 100 are connected in series using a conductive element 20. The 5 battery packs 10 are placed on the bottom plate 31 of a receiving space 301 in the housing 30. Another 50 batteries 100 are also grouped into 5 battery packs 10 of 10, with adjacent batteries 100 stacked with their large surfaces facing each other, and connected in series using a conductive element 20. Fifty batteries 100 are connected in series, and five battery packs 10 are placed on the bottom plate 31 of another receiving space 301 of the housing 30. The two receiving spaces 301 are separated by a first partition beam 33. The large surface of the battery 100 in the battery pack 10 is parallel to the length direction of the first partition beam 33 (the length direction is parallel to the plane where the bottom plate 31 is located), and the length direction of the battery pack 10 is also parallel to the length direction of the first partition beam 33. A heat exchange assembly is set between adjacent batteries 100. The length direction of the first partition beam 33 along the stacking direction of the batteries 100 in the battery pack 10 (the stacking direction of the batteries 100 in the battery pack 10 is parallel to the plane where the bottom plate 31 is located) is the second direction. The stacking direction of the batteries 100 in the battery pack 10 is the first direction.

[0173] The dimension of the connection between the conductive element 20 and the battery 100 in the third direction is d1. In the second direction, the ratio of the dimension of the bent portion 201 of the conductive element 20 to the dimension of the conductive element 20 is a1. The dimension of the first partition beam 33 in the first direction is D1. The dimension of the heat exchange assembly in the first direction is D2. Except for the parameters in Table 1, the structures of the rest of the battery pack are the same.

[0174] Charge the batteries 100 in the two storage spaces 301 to the upper limit voltage at a 4C rate. Measure and record the highest temperature of the batteries 100 during the process. If the temperature is greater than 45℃, it is unqualified; otherwise, it is qualified.

[0175] When the main cathode material of battery 100 is lithium iron phosphate, the upper limit voltage is 3.65V and the lower limit voltage is 2.5V. When the main cathode material of battery 100 is lithium nickel cobalt manganese oxide, the upper limit voltage is 4.25V and the lower limit voltage is 2.5V.

[0176] This test uses a ternary lithium battery as an example.

[0177] Table 1 Test parameters and results

[0178]

[0179] Compared to Comparative Examples 1 and 3, when d1, a1, D1, and D2 satisfy: 0.004 × 10 -3 When ≤ (a1×d1) / (D1+D2), the breakage rate of conductive component 20 is less than or equal to 2%. Limiting d1, a1, D1 and D2 can make the conductive component less prone to breakage.

[0180] Compared to Comparative Examples 2 and 4, when d1, a1, D1, and D2 satisfy: (a1×d1) / (D1+D2)≤1.7×10 -3 At that time, the temperature of battery 100 was less than 45℃. Limiting d1, a1, D1 and D2 can improve the heat dissipation of the battery pack.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery pack, characterized in that, include: A battery pack, comprising multiple batteries, wherein the multiple batteries are stacked in a large-to-large-face manner, and the stacking direction of the multiple batteries is a first direction; Multiple conductive components, each conductive component including at least one bent portion and at least two connecting portions, wherein the bent portion is connected to one connecting portion at each end in the first direction, the bent portion is disposed between two adjacent batteries, and is electrically connected to the battery through the connecting portions; The enclosure includes a main body and at least one first partition beam. The main body includes a bottom plate and a frame. The frame is disposed on the bottom plate and forms a receiving cavity. The first partition beam is disposed in the receiving cavity and extends along a second direction, dividing the receiving cavity into at least two receiving spaces. The receiving spaces are used to house the battery pack. A heat exchange assembly is disposed between two adjacent batteries and extends along the second direction; The direction perpendicular to the base plate is defined as the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other; The dimension of the connection between the conductive component and the battery in the third direction is d1. In the second direction, the ratio of the dimension of the bent portion to the dimension of the conductive component is a1. The dimension of the first partition beam in the first direction is D1. The dimension of the heat exchange assembly in the first direction is D2. The following conditions are met: d1, a1, D1, and D2 satisfy: 0.004×10 -3 ≤(a1×d1) / (D1+D2)≤1.7×10 -3 Wherein, the units of d1, D1 and D2 are all mm.

2. The battery pack according to claim 1, characterized in that, The condition a1 satisfies: 0.04≤a1≤0.

5.

3. The battery pack according to claim 1, characterized in that, In the first direction, a plurality of conductive elements are arranged sequentially at intervals, and the interval between two adjacent conductive elements is L2, wherein L2 satisfies: 2mm≤L2≤20mm.

4. The battery pack according to claim 1, characterized in that, The battery includes a terminal post, which is welded to the conductive element. In the first direction, the end of the conductive element extends beyond the terminal post, and the dimension by which the end of the conductive element extends beyond the terminal post is L1, wherein L1 satisfies: 1mm≤L1≤5mm.

5. The battery pack according to claim 1, characterized in that, The battery includes a terminal post, the terminal post is provided with a welding area, the connecting part is welded to the welding area, and in the first direction, the minimum distance between the bent part and the welding area is L3, wherein L3 satisfies: 2mm≤L3≤10mm.

6. The battery pack according to claim 1, characterized in that, The conductive element has a dimension L4 in the first direction, and L4 satisfies: 50mm≤L4≤160mm.

7. The battery pack according to claim 1, characterized in that, In the second direction, a plurality of conductive elements are arranged sequentially at intervals, and the interval between two adjacent conductive elements is L5, wherein L5 satisfies: 10mm≤L5≤260mm.

8. The battery pack according to claim 1, characterized in that, The conductive element has a dimension of L6 in the second direction, and L6 satisfies: 25mm≤L6≤60mm.

9. The battery pack according to claim 1, characterized in that, In the second direction, the ratio of the size of the bent portion to the size of the conductive element is a2, and a2 satisfies: a2≥0.

8.

10. The battery pack according to claim 1, characterized in that, In the second direction, a plurality of conductive elements are arranged sequentially at intervals, and the sum of the dimensions of each conductive element is D3, wherein D1, D2, and D3 satisfy: 0.96≤D3 / (D1+D2)≤9.5, where the units of D1, D2 and D3 are all mm.

11. The battery pack according to claim 1, characterized in that, The d1 satisfies: 0.8mm≤d1≤2.5mm.

12. The battery pack according to claim 1, characterized in that, The dimension of the bent portion in the third direction is d2, and d1 and d2 satisfy: 0.2≤d1 / d2≤1.

6.

13. The battery pack according to claim 1, characterized in that, The battery is welded to the conductive component. The length direction of the weld is parallel to the second direction, and the width direction of the weld is parallel to the first direction. The ratio a3 of the dimension of the weld in the second direction to the dimension of the weld in the first direction satisfies: 1.1≤a3≤4.

2.

14. The battery pack according to claim 1, characterized in that, In the second direction, the end of the heat exchange plate extends beyond the end of the battery pack by a dimension L7, wherein L7 satisfies: 20mm≤L7≤50mm.

15. The battery pack according to claim 1, characterized in that, In the second direction, the end of the heat exchange plate abuts against the housing.

16. The battery pack according to claim 1, characterized in that, In the second direction, the end of the heat exchange plate is spaced apart from the housing, and the distance between the end of the heat exchange plate and the housing is L8, wherein L8 satisfies: 5mm≤L8≤100mm.

17. The battery pack according to claim 16, characterized in that, In the second direction, the ratio of the size of the heat exchange plate to the size of the first partition beam is a4, where a4 satisfies: 0.6≤a4≤1.

18. The battery pack according to claim 1, characterized in that, The condition D2 satisfies: 70mm≤D2≤210mm.

19. The battery pack according to claim 18, characterized in that, The heat exchange assembly includes multiple heat exchange plates, which are spaced apart along the first direction. The dimension of a single heat exchange plate in the first direction is L9, and L9 satisfies: 3.5mm≤L9≤7mm.

20. The battery pack according to claim 18, characterized in that, The heat exchange plate is provided with a liquid inlet and a liquid outlet, which are located on the same side of the heat exchange plate in the second direction. The dimension of the heat exchange plate in the first direction is L9, and L9 satisfies: 4mm≤L9≤7mm.

21. The battery pack according to claim 18, characterized in that, The heat exchange plate is provided with a liquid inlet and a liquid outlet, which are respectively located on both sides of the heat exchange plate in the second direction. The dimension of the heat exchange plate in the first direction is L9, and L9 satisfies: 3.5mm≤L9≤6mm.

22. The battery pack according to claim 1, characterized in that, In the first direction, a heat exchange plate is provided between any two adjacent batteries. The size of the heat exchange plate is L9, and L9 satisfies: 3.5mm≤L9≤5mm.

23. The battery pack according to claim 1, characterized in that, In the first direction, a plurality of batteries are arranged between adjacent heat exchange plates, and the size of the heat exchange plate is L9, wherein L9 satisfies: 4mm≤L9≤7mm.

24. The battery pack according to claim 1, characterized in that, In the first direction, the minimum distance between the heat exchange plate and the first partition beam is L10, and L10 satisfies: L10≥1mm.

25. The battery pack according to claim 1, characterized in that, In the first direction, the minimum distance between two adjacent heat exchange plates in the accommodating space is L11, and L11 satisfies: L11≥4mm.

26. The battery pack according to claim 1, characterized in that, In the third direction, the ratio of the size of the projection of the heat exchange plate onto the large surface of the battery along the first direction to the size of the battery is a5, where a5 satisfies: 0.6≤a5≤1.

27. The battery pack according to claim 1, characterized in that, The condition D1 satisfies: 10mm≤D1≤50mm.

28. The battery pack according to any one of claims 1-27, characterized in that, The battery pack is provided in both adjacent containment spaces, and the positive electrode material of the battery in at least one containment space is lithium nickel cobalt manganese oxide.

29. The battery pack according to any one of claims 1-27, characterized in that, The battery has a capacity of 150Ah or greater and 600Ah or less.

30. The battery pack according to any one of claims 1-27, characterized in that, The main body of the box also includes a cover plate, which is sealed to the first partition beam. In the third direction, the bottom plate is located at the bottom of the frame, the cover plate is located at the top of the frame, and the top of the partition beam is sealed to the cover plate.

31. The battery pack according to claim 30, characterized in that, In the third direction, the top of the first partition beam is higher than the top of the conductive element, and the distance between the top of the first partition beam and the top of the conductive element is L12, where L12 satisfies: 0.5mm≤L12≤5mm.

32. The battery pack according to claim 30, characterized in that, In the third direction, the top of the first partition beam is lower than the top of the conductive element, and the distance between the top of the first partition beam and the top of the conductive element is L13, where L13 satisfies: 2mm≤L13≤8mm.

33. The battery pack according to claim 30, characterized in that, The enclosure also includes a second partition beam disposed inside the enclosure. The second partition beam is connected to one end of the first partition beam. The second partition beam divides the interior of the enclosure into an electrical compartment and a receiving cavity. The electrical compartment and the receiving cavity are independently sealed, and two adjacent receiving spaces are independently sealed.

34. The battery pack according to claim 33, characterized in that, Each of the aforementioned containment spaces is sealed, and the battery packs within each of the aforementioned containment spaces are connected in series and / or in parallel via the conductive element.

35. The battery pack according to any one of claims 1-27, characterized in that, At least one of the accommodating spaces is provided with a reinforcing member, the reinforcing member extends along a first direction and covers at least two of the batteries along the first direction, the overlapping area of ​​the reinforcing member and the batteries is S1, the surface area of ​​the batteries on the side where the reinforcing member is located is S2, and the ratio of S1 to S2 is greater than or equal to 0.01 and less than or equal to 0.

1.

36. The battery pack according to claim 35, characterized in that, Each of the accommodating spaces is provided with a plurality of battery packs, which are arranged along the second direction.

37. The battery pack according to claim 36, characterized in that, In the second direction, two adjacent battery packs are connected by one of the reinforcing members.

38. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1-37.

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