Battery pack

Abstract

The battery pack comprises a box body and a cylindrical battery pack located in the box body, the box body comprises a bottom plate, the cylindrical battery pack comprises at least two cylindrical batteries, the axial directions of the cylindrical batteries are parallel to the bottom plate, a heat exchange plate is perpendicular to the bottom plate, and the heat exchange plate is located at the axial ends of the cylindrical batteries and adheres to the cylindrical batteries through adhesive layers; in the direction perpendicular to the bottom plate, at least one end area of the side face, facing the cylindrical battery, of the heat exchange plate is provided with a first blocking piece, the proportion of the width of the first blocking piece in the direction perpendicular to the bottom plate to the width of the heat exchange plate is m, the axial length of the cylindrical battery is l, and m * l is larger than or equal to 2.4 mm and smaller than or equal to 4 mm. According to the battery pack, the first blocking piece is arranged to prevent glue from overflowing, the value of m * l is controlled to be 2.4 mm-4mm, the fixing strength of the cylindrical battery and the heat exchange plate can be guaranteed, and meanwhile the heat exchange effect of the cylindrical battery and the heat exchange plate, the glue blocking effect of the first blocking piece and the energy density of the whole battery pack can be guaranteed.

Description

Technical Field

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

[0002] In some battery packs, the cylindrical cells are arranged with their axial direction parallel to the bottom plate of the battery pack housing. A heat exchange plate is installed at the end of each cylindrical cell, and the end of the cylindrical cell is bonded to the heat exchange plate with an adhesive layer. In this case, the weight of the cylindrical cell is perpendicular to the bottom plate, and this weight generates a torque at the bonding point between the cylindrical cell and the heat exchange plate, resulting in significant stress at this point. Therefore, high requirements are placed on the fixing strength between the cylindrical cell and the heat exchange plate. Simultaneously, the cylindrical cell needs to exchange heat with the heat exchange plate to maintain its normal operating temperature. Therefore, how to ensure the fixing strength of the cylindrical cell and the heat exchange plate while also considering the heat exchange effect is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0003] To solve the above-mentioned technical problems, this application provides a battery pack, the battery pack including a housing and a cylindrical battery pack located inside the housing, the housing including a bottom plate, the cylindrical battery pack including at least two cylindrical batteries, the axial direction of the cylindrical batteries being parallel to the bottom plate, the heat exchange plate being perpendicular to the bottom plate, the heat exchange plate being located at one axial end of the cylindrical batteries and bonded to the cylindrical batteries through the adhesive layer, in a direction perpendicular to the bottom plate, at least one end of the heat exchange plate facing the cylindrical batteries is provided with a first blocking member, the width of the first blocking member in the direction perpendicular to the bottom plate being a ratio of m to the width of the heat exchange plate, the axial length of the cylindrical batteries being l, 2.4mm≤m*l≤4mm.

[0004] This application sets a first blocking component to prevent adhesive overflow. This application controls the value of m*l to 2.4mm-4mm, which can ensure the fixing strength between the cylindrical battery and the heat exchange plate, and at the same time ensure the heat exchange effect between the cylindrical battery and the heat exchange plate, the adhesive blocking effect of the first blocking component, and the energy density of the entire battery pack. Attached Figure Description

[0005] Figure 1 Top view of a partial structure of an embodiment of the battery pack provided in this application;

[0006] Figure 2 for Figure 1 A partial 3D view;

[0007] Figure 3 for Figure 1 A perspective view of the heat exchange plate and the first baffle.

[0008] Figure 4A schematic diagram showing that a second blocking element is provided at both ends of the heat exchange plate parallel to the bottom plate on the side facing the cylindrical battery.

[0009] Figure 5 This is a 3D view of a cylindrical battery.

[0010] Figure 6 This is an orthographic projection of a cylindrical battery on the side of the heat exchange plate facing the cylindrical battery in one embodiment.

[0011] Figure 7 This is an orthographic projection of the cylindrical battery on the side of the heat exchange plate facing the cylindrical battery in another embodiment.

[0012] The annotations in the attached figures are explained as follows:

[0013] 1. Box body, 11. Base plate, 2. Cylindrical battery, 21. Shell, 22. Terminal, 3. Heat exchange plate, 4. First blocking component, 5. Second blocking component, 6. Conductive component. Detailed Implementation

[0014] This application provides a battery pack. To enable those skilled in the art to better understand the technical solution of this application, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0015] like Figure 1 and Figure 2 As shown, the battery pack provided in this application includes a housing 1, a cylindrical battery pack, and a heat exchange plate 3. The housing 1 includes a base plate 11. The cylindrical battery pack is located inside the housing 1 and includes cylindrical batteries 2, the axial direction of which is parallel to the base plate 11. The heat exchange plate 3 is located inside the housing 1 and is perpendicular to the base plate 11. The heat exchange plate 3 is located at one axial end of the cylindrical battery pack and is bonded to the cylindrical batteries 2 through an adhesive layer.

[0016] Specifically, Figure 1 and Figure 2 The device comprises four rows of cylindrical battery packs, arranged sequentially along a first direction, with the axial direction of the cylindrical batteries 2 parallel to this first direction. A heat exchange plate 3 is provided between two adjacent rows of cylindrical battery packs, and another heat exchange plate 3 is provided between two adjacent rows of cylindrical battery packs. In actual implementation, the number of rows of cylindrical battery packs can be less than four or more than four.

[0017] like Figure 3 As shown, in a direction perpendicular to the base plate 11, at least one end of the heat exchange plate 3 facing the side of the cylindrical battery 2 is provided with a first blocking member 4. Figure 3 In the direction perpendicular to the base plate 11, the heat exchange plate 3 is provided with a first blocking member 4 at both ends of the side facing the cylindrical battery 2. Alternatively, the first blocking member 4 can be provided only at one end.

[0018] like Figure 4 As shown, in the direction perpendicular to the base plate 11, the width of the first blocking member 4 (W1 in the figure) accounts for a ratio of m to the width of the heat exchange plate 3 (W in the figure). Figure 5 As shown, the axial length of the cylindrical battery 2 is l. 2.4mm ≤ m*l ≤ 4mm. For example, m*l can be equal to 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, or 4mm.

[0019] When the value of m*l is too small, it means that the ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 in the direction perpendicular to the base plate 11 is too small, or the axial length l of the cylindrical battery 2 is too small. A small ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 in the direction perpendicular to the base plate 11 will result in poor adhesive blocking effect and severe adhesive overflow. A small axial length l of the cylindrical battery 2 will result in low energy density of the entire battery pack.

[0020] When the value of m*l is too large, it means that the ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 in the direction perpendicular to the base plate 11 is too large, or the axial length l of the cylindrical battery 2 is too large. An excessively large ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 in the direction perpendicular to the base plate 11 will lead to a decrease in heat exchange efficiency between the heat exchange plate 3 and the cylindrical battery 2, resulting in poor heat exchange performance. It will also reduce the bonding area between the heat exchange plate 3 and the cylindrical battery 2, resulting in low fixing strength between the cylindrical battery 2 and the heat exchange plate 3. An excessively large axial length l of the cylindrical battery 2 will result in excessive force on the cylindrical battery 2 in the direction perpendicular to the base plate 11, and an excessively large distance (i.e., lever arm) between this force and the bonding position of the cylindrical battery 2 and the heat exchange plate 3, resulting in insufficient fixing strength between the cylindrical battery 2 and the heat exchange plate 3.

[0021] This application controls the value of m*l to 2.4mm-4mm, which can ensure the fixing strength between the cylindrical battery 2 and the heat exchange plate 3, and at the same time ensure the heat exchange effect between the cylindrical battery 2 and the heat exchange plate 3, the adhesive blocking effect of the first blocking member 4, and the energy density of the entire battery pack.

[0022] In some embodiments, the end face area S of the cylindrical battery 2 ranges from 200 cm². 2 ≤S≤800cm 2 In this case, the range of m*l is further narrowed to: 2.4mm≤m*l≤3.6mm.

[0023] When the end face area S of cylindrical battery 2 is 200cm² 2 -800cm 2Within the specified range, most of the side of the heat exchange plate 3 facing the cylindrical battery 2 needs to be bonded to the end face of the cylindrical battery 2, resulting in a smaller arrangement space for the first blocking member 4. Therefore, the width of the first blocking member 4 needs to be set smaller. Consequently, the ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 decreases, and the upper limit of m*l is further reduced.

[0024] In some embodiments, first blocking members 4 are provided at both ends of the heat exchange plate 3 facing the cylindrical battery 2 in a direction perpendicular to the base plate 11, as shown in the illustrated scheme. In this case, the range of m*l is further narrowed to: 2.4mm ≤ m*l ≤ 3.7mm.

[0025] With a fixed width of the first blocking member 4, the first blocking member 4 is provided at both ends of the heat exchange plate 3 facing the cylindrical battery 2. Compared with the first blocking member 4 being provided at only one end, the heat exchange effect of the heat exchange plate 3 and the cylindrical battery 2 will decrease. In order to ensure the heat exchange effect, the width of the first blocking member 4 needs to be reduced. Therefore, the value of m decreases, so the upper limit of m*l is further reduced.

[0026] In some embodiments, such as Figure 6 As shown, the orthographic projection of the cylindrical battery 2 onto the side of the heat exchange plate 3 facing the cylindrical battery 2 at least partially overlaps with the first blocking member 4. This at least partial overlap is more conducive to ensuring the thickness of the adhesive layer between the end face of the cylindrical battery 2 and the heat exchange plate 3, and is more conducive to ensuring the fixing strength between the cylindrical battery 2 and the heat exchange plate 3.

[0027] In some embodiments, such as Figure 7 As shown, the orthographic projection of the cylindrical battery 2 onto the side of the heat exchange plate 3 facing the cylindrical battery 2 is offset from and does not overlap with the first blocking member 4. This offset and non-overlapping arrangement is more conducive to ensuring the heat exchange area between the cylindrical battery 2 and the heat exchange plate 3, and is more conducive to ensuring the heat exchange effect between the cylindrical battery 2 and the heat exchange plate 3.

[0028] In some embodiments, the width (W1 in the figure) of the first blocking member 4 in the direction perpendicular to the base plate 11 ranges from 1mm to 10mm. For example, it can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm.

[0029] In some embodiments, the width of the heat exchange plate 3 (W2 in the figure) in the direction perpendicular to the base plate 11 ranges from 40mm to 260mm. For example, it can be 40mm, 60mm, 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 200mm, 220mm, 240mm, or 260mm.

[0030] In some embodiments, the range of m is: 0.01≤m≤0.04, for example, it can be 0.01, 0.02, 0.03, or 0.04.

[0031] In some embodiments, the axial length l of the cylindrical battery 2 is in the range of 80mm ≤ l ≤ 200mm. For example, it can be 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, or 200mm.

[0032] In some embodiments, at least one end of the heat exchange plate 3 facing the cylindrical battery 2 is provided with a second blocking member 5 in a direction parallel to the base plate 11. The width of the second blocking member 5 in the direction parallel to the base plate 11 ( Figure 4 W2) occupies 3 of the heat exchange plate length ( Figure 4 The ratio of L to n is 0.008 ≤ n ≤ 0.015. For example, n can be equal to 0.008, 0.009, 0.01, 0.012, 0.013, 0.014, or 0.015. If the value of n is too large, the heat exchange efficiency between the heat exchange plate 3 and the cylindrical battery 2 will decrease, resulting in poor heat exchange effect. If the value of n is too small, the adhesive-blocking effect of the second barrier 5 will be poor, resulting in serious adhesive overflow. Controlling n within the range of 0.008-0.015 can simultaneously ensure the heat exchange effect between the heat exchange plate 3 and the cylindrical battery 2 and the adhesive-blocking effect of the second barrier 5.

[0033] With the second blocking member 5 installed, the range of m*l is further narrowed to: 2.4mm ≤ m*l ≤ 3.4mm. Installing the second blocking member 5 reduces the heat exchange effect between the heat exchange plate 3 and the cylindrical battery 2. To ensure the heat exchange effect, the width of the first blocking member 4 needs to be further reduced. Therefore, the ratio m of the width of the first blocking member 4 to the width of the heat exchange plate 3 decreases, thus further reducing the upper limit of m*l.

[0034] In some embodiments, such as Figure 4 As shown, in a direction parallel to the base plate 11, the heat exchange plate 3 has second blocking members 5 at both ends of the side facing the cylindrical battery 2. In this case, the range of m*l is further narrowed to: 2.4mm≤m*l≤3.2mm.

[0035] The heat exchange plate 3 is provided with second blocking members 5 at both ends of the side facing the cylindrical battery 2. Compared with providing second blocking members 5 at only one end, the heat exchange effect of the heat exchange plate 3 and the cylindrical battery 2 will decrease. In order to ensure the heat exchange effect, the width of the first blocking member 4 needs to be reduced. Therefore, the value of m is reduced, so the upper limit of m*l is further reduced.

[0036] In some embodiments, such as Figure 6As shown, the orthographic projection of the cylindrical battery 2 onto the side of the heat exchange plate 3 facing the cylindrical battery 2 at least partially overlaps with the second blocking member 5. This at least partial overlap is more conducive to ensuring the thickness of the adhesive layer between the end face of the cylindrical battery 2 and the heat exchange plate 3, and is more conducive to ensuring the fixing strength between the cylindrical battery 2 and the heat exchange plate 3.

[0037] In some embodiments, such as Figure 7 As shown, the orthographic projection of the cylindrical battery 2 onto the side of the heat exchange plate 3 facing the cylindrical battery 2 is offset from and does not overlap with the second blocking member 5. This offset and non-overlapping arrangement is more conducive to ensuring the heat exchange area between the cylindrical battery 2 and the heat exchange plate 3, and is more conducive to ensuring the heat exchange effect between the cylindrical battery 2 and the heat exchange plate 3.

[0038] In some embodiments, the width (W2) of the second blocking member 5 in the direction parallel to the base plate 11 ranges from 4.5mm to 20mm. For example, it can be 4.5mm, 8mm, 10mm, 12mm, 14mm, 16mm, or 20mm.

[0039] In some embodiments, the length (L) of the heat exchange plate 3 in the direction parallel to the base plate 11 ranges from 600mm to 1500mm. For example, it can be 600mm, 800mm, 1000mm, 1200mm, 1400mm, or 1500mm.

[0040] In some embodiments, such as Figure 3 As shown, a conductive element 6 is provided at the other end of the cylindrical battery 2 along its axial direction, and multiple cylindrical batteries 2 are fixedly connected through the conductive element 6. In this case, the range of m*l is further narrowed to: 2.4mm≤m*l≤3.6mm. The conductive element 6 improves the fixing strength of the cylindrical battery 2, so the thickness of the adhesive layer can be reduced, so the blocking capacity of the first blocking element 4 can be reduced, and thus the width of the first blocking element 4 can be smaller, thereby further reducing m and the upper limit of m*l. At the same time, the further reduction of m also helps to improve the heat exchange effect of the heat exchange plate 3 and the cylindrical battery 2.

[0041] In some embodiments, the cylindrical battery 2 includes two tabs of different polarities, and, as... Figure 5As shown, the cylindrical battery 2 also includes a housing 21 and terminals 22 disposed on the housing 21. One polarity of the terminal tab is electrically connected to the terminal 22, and the other polarity of the terminal tab is electrically connected to the housing 21. In this case, the range of m*l can be further narrowed to: 2.8mm ≤ m*l ≤ 3.6mm. The housing 21 is electrically connected to one polarity of the terminal tab, which improves the heat dissipation capacity of the cylindrical battery 2. Therefore, the width of the first blocking member 4 can be appropriately increased to improve the adhesive blocking ability, thus further increasing m and the lower limit of m*l. Simultaneously, this design also gives the terminal 22 better overcurrent capacity, thereby giving the battery pack better fast charging capability.

[0042] The above examples illustrate the principles and implementation methods of this application. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing, a cylindrical battery pack located inside the housing, and a heat exchange plate. The housing includes a bottom plate, the cylindrical battery pack includes cylindrical batteries, the axial direction of the cylindrical batteries is parallel to the bottom plate, the heat exchange plate is perpendicular to the bottom plate, the heat exchange plate is located at one axial end of the cylindrical batteries and is bonded to the cylindrical batteries through the adhesive layer, and in the direction perpendicular to the bottom plate, at least one end of the heat exchange plate facing the cylindrical batteries is provided with a first blocking member, and in the direction perpendicular to the bottom plate, the width of the first blocking member is a ratio of m to the width of the heat exchange plate, and the axial length of the cylindrical batteries is l, where 2.4mm ≤ m * l ≤ 4mm.

2. The battery pack according to claim 1, characterized in that, The end face area S of the cylindrical battery is in the range of 200 cm². 2 ≤S≤800cm 2 , 2.4mm≤m*l≤3.6mm.

3. The battery pack according to claim 1, characterized in that, In a direction perpendicular to the base plate, the first blocking member is provided at both ends of the heat exchange plate facing the cylindrical battery, with a diameter of 2.4mm ≤ m*l ≤ 3.7mm.

4. The battery pack according to claim 1, characterized in that, The orthographic projection of the cylindrical battery onto the side of the heat exchange plate facing the cylindrical battery is at least partially overlapping with the first blocking member or is offset from the first blocking member and does not overlap.

5. The battery pack according to claim 1, characterized in that, In the direction perpendicular to the base plate, the width of the first blocking member ranges from 1mm to 10mm, the width of the heat exchange plate ranges from 40mm to 260mm, and the range of m is: 0.01≤m≤0.

04.

6. The battery pack according to claim 1, characterized in that, The axial length l of the cylindrical battery is in the range of 80mm≤l≤200mm.

7. The battery pack according to any one of claims 1-6, characterized in that, In a direction parallel to the base plate, at least one end of the heat exchange plate facing the cylindrical battery is provided with a second blocking member. In the direction parallel to the base plate, the width of the second blocking member is in proportion to the length of the heat exchange plate as n, where 0.008≤n≤0.015 and 2.4mm≤m*l≤3.4mm.

8. The battery pack according to claim 7, characterized in that, In a direction parallel to the base plate, the heat exchange plate is provided with the second blocking member at both ends of the side facing the cylindrical battery, with a diameter of 2.4mm ≤ m*l ≤ 3.2mm.

9. The battery pack according to claim 7, characterized in that, The orthographic projection of the cylindrical battery onto the side of the heat exchange plate facing the cylindrical battery is at least partially overlapping with the second blocking member or is offset from the second blocking member and does not overlap.

10. The battery pack according to claim 7, characterized in that, In the direction parallel to the base plate, the width of the second blocking member ranges from 4.5mm to 20mm, and the length of the heat exchange plate ranges from 600mm to 1500mm.

11. The battery pack according to any one of claims 1-6, characterized in that, A conductive element is provided at the other end of the cylindrical battery along its axial direction, and multiple cylindrical batteries are fixedly connected through the conductive element, with a diameter of 2.4mm ≤ m*l ≤ 3.6mm.

12. The battery pack according to any one of claims 1-6, characterized in that, The cylindrical battery includes two tabs of different polarities, a casing, and a terminal post disposed on the casing. The tab of one polarity is electrically connected to the terminal post, and the tab of the other polarity is electrically connected to the casing. 2.8mm≤m*l≤3.6mm.

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