A battery pack, a battery pack and an electrical apparatus

Abstract

The application discloses a battery pack, a battery pack and a power utilization equipment, and relates to the technical field of batteries. The battery pack comprises a bottom plate and a plurality of cylindrical batteries arranged on the bottom plate. The axial direction of the cylindrical batteries is parallel to the plane where the bottom plate is located. In the direction perpendicular to the bottom plate, the cylindrical batteries are at least two layers, and the adjacent two layers of cylindrical batteries are arranged staggeredly. The outer circumferential surface of the shell of at least one cylindrical battery is provided with a temperature acquisition device. The line connecting the temperature acquisition device and the center of the cylindrical battery where the temperature acquisition device is located is an installation position line. The included angle between the installation position line and the plane where the bottom plate is located is an installation angle. The angle of the installation angle is a°, and the range of a° is 5°-85°. The temperature acquisition device is arranged at a position with an installation angle of 5°-85°, which can not only reduce the peeling force of the connection caused by the vibration load, but also reduce the temperature influence of the adjacent cylindrical batteries, and improve the temperature acquisition accuracy.

Description

[0001] This application is a divisional application filed on May 14, 2025, with application number 202510618594.0, and entitled "A Battery Pack, Battery Module and Electrical Equipment". Technical Field

[0002] This application relates to the field of battery pack technology, and more specifically, to a battery pack, battery assembly, and electrical device. Background Technology

[0003] Batteries may experience thermal runaway under conditions such as overcharging, over-discharging, short circuits, or high temperatures, leading to fire or explosion. Real-time temperature monitoring can trigger protection mechanisms in a timely manner, such as cutting off the circuit or activating the cooling system. Abnormally high temperatures may signal internal faults (such as short circuits or aging), so monitoring battery issues can provide early warnings to prevent accidents. Furthermore, battery thermal management control also requires monitoring battery temperature and, based on temperature data, activating the cooling system or heating device to maintain the battery within its optimal operating temperature range.

[0004] In cylindrical battery packs, the poor flatness of the battery surface and the limited position result in weak fixation of the temperature acquisition device and the battery casing, affecting the connection strength between the temperature acquisition and the battery casing, as well as the accuracy of temperature acquisition.

[0005] Therefore, how to balance the installation strength of the temperature acquisition device with the accuracy of temperature acquisition is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide a battery pack that balances the installation strength of the temperature acquisition device and the accuracy of temperature acquisition. Another object of this application is to provide a battery pack and electrical device having the above-mentioned battery pack.

[0007] To achieve the above objectives, this application provides the following technical solution.

[0008] The first aspect of this application provides a battery pack, including a base plate and a plurality of cylindrical batteries disposed on the base plate. The axial direction of the cylindrical batteries is parallel to the plane on which the base plate is located. Along a direction perpendicular to the base plate, the cylindrical batteries are at least two layers, and adjacent layers of cylindrical batteries are staggered. The layer of cylindrical batteries closest to the base plate is the first cylindrical battery, and the layer of cylindrical batteries farthest from the base plate is the second cylindrical battery. At least one of the cylindrical batteries has a temperature acquisition device disposed on the outer peripheral surface of its casing. The temperature acquisition device on the first cylindrical battery is located on the side closer to the base plate, and the temperature acquisition device on the second cylindrical battery is located on the side farther from the base plate. The line connecting the temperature acquisition device to the center of the cylindrical battery on which it is located is the installation position line. The angle between the installation position line and the plane on which the base plate is located is the installation angle. The angle of the installation angle is a°, and the range of a° is 5°~85°.

[0009] The battery pack provided in this application comprises at least two layers of cylindrical cells along a direction perpendicular to the base plate, with adjacent layers of cylindrical cells staggered. A temperature sensing device is installed on the outer circumference of the cylindrical cells. The line connecting the temperature sensing device to the center of the cylindrical cell it is located is the installation position line, and the angle between the installation position line and the plane of the base plate is controlled between 5° and 85°. When the cylindrical cells are in a vibration environment, the temperature sensing device is positioned at an installation angle α between 5° and 85°. If the installation angle is too large, it will be subjected to a greater inertial force in the vertical direction. In this case, when the cylindrical cells vibrate up and down, the inertial force of the temperature sensing device will cause the connection to be subjected to a peeling force perpendicular to the circumference of the cylindrical cells, making it easier for the connection to be pulled apart. If the installation angle is too small, although the peeling force is smaller and the connection is less likely to be pulled apart, the distance to the adjacent cylindrical cells is closer, making it easier to be affected by the temperature of the adjacent cylindrical cells, thus affecting the temperature sensing accuracy.

[0010] This application positions the temperature acquisition device at an installation angle α between 5° and 85°, which can reduce the peeling force at the connection caused by vibration load and reduce the temperature influence of the adjacent cylindrical battery, thereby improving the temperature acquisition accuracy.

[0011] Furthermore, the temperature acquisition device on the first cylindrical battery is positioned on the side closer to the base plate, while the temperature acquisition device on the second cylindrical battery is positioned on the side farther from the base plate. That is, the temperature acquisition device is not located between the two cylindrical battery layers to ensure the accuracy of the temperature data acquisition.

[0012] A second aspect of this application provides a battery pack including a frame, a cover, and a battery assembly as described in any of the preceding claims, wherein the frame is connected to a base plate of the battery assembly, and the cover is sealed to the frame.

[0013] The battery pack provided in this application has all the technical effects of the aforementioned battery pack, which will not be elaborated here.

[0014] A third aspect of this application provides an electrical device including a battery pack as described above.

[0015] The electrical equipment provided in this application has the aforementioned battery pack, and therefore possesses all the technical effects of the aforementioned battery pack, which will not be elaborated upon here. 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 only 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 battery pack structure disclosed in the embodiments of this application; Figure 2 This is a partial cross-sectional view of the battery pack disclosed in an embodiment of this application; Figure 3 This is a schematic diagram showing the angular relationship between the temperature acquisition device and the cylindrical battery disclosed in an embodiment of this application; Figure 4 This is a schematic diagram showing the angular relationship between the temperature acquisition device and the cylindrical battery disclosed in another embodiment of this application; Figure 5 This is a schematic diagram of the battery pack disclosed in this application after removing some of the cylindrical batteries; Figure 6 This is a schematic diagram of the structure of a cylindrical battery equipped with a temperature acquisition device, as disclosed in an embodiment of this application. Figure 7 This is a side view of a cylindrical battery with a temperature acquisition device installed, as disclosed in an embodiment of this application. Figure 8 for Figure 7 A sectional view along line AA.

[0018] The meanings of the various reference numerals in the figure are as follows: 100 - Battery housing; 101 - Base plate; 102 - Supporting partition; 200 - Cylindrical battery; 201 - Mounting position connection; 202 - Reference position connection; 300 - Conductive component; 400 - Heat exchanger; 500 - Temperature acquisition device. Detailed Implementation

[0019] This application discloses a battery pack that balances the installation strength of the temperature acquisition device with the accuracy of temperature acquisition. This application also discloses an electrical device having the above-described battery pack.

[0020] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the application as described in the claims. Additionally, the complete composition represented in the embodiments below is not limited to what is necessary as the solution to the application described in the claims. It should be noted that, for ease of description, only the parts relevant to the application are shown in the drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0021] In cylindrical battery packs, the applicant found that for horizontally placed cylindrical batteries with their axis parallel to the base plate, the temperature acquisition device is typically fixed to the outer circumference of the battery. The placement of the temperature acquisition device on the outer circumference of the battery, while meeting installation requirements, is arbitrarily determined, resulting in insecure fixation. While some installation methods can ensure the installation strength of the temperature acquisition device, they affect its accuracy. In some installation methods, especially in harsh vibration environments, the risk of the temperature acquisition device detaching is increased. Other installation methods, while ensuring the installation strength of the temperature acquisition device, compromise its accuracy.

[0022] The applicant's research revealed that temperature acquisition devices are typically glued to the outer circumference of cylindrical batteries. During bonding, the temperature acquisition device can be directly glued to the outer circumference of the cylindrical battery, or it can be glued to the outer circumference of the cylindrical battery together with other fasteners. The adhesive layer's ability to withstand shear force is significantly greater than its ability to withstand peel force; the force perpendicular to the adhesive layer is the peel force, and the force along the circumference of the cylindrical battery is the shear force.

[0023] When battery packs are used in vehicles, the vehicle's operating environment makes them susceptible to vertical vibration loads. If the temperature sensing device is positioned at the highest point (12 o'clock position) of the cylindrical battery in the direction perpendicular to the base plate, it will be subjected to a greater vertical inertial force. In this case, when the cylindrical battery vibrates up and down, the inertial force of the temperature sensing device will cause a large peeling force perpendicular to the circumference of the cylindrical battery at the connection point, easily leading to the connection point being pulled apart.

[0024] If the temperature acquisition device is placed at the 3 o'clock or 9 o'clock position of the cylindrical battery, although when the battery pack is subjected to vertical vibration load, the temperature acquisition device installed at this position will mainly be subjected to shear force rather than peeling force, and the connection will not be easily pulled apart, the distance to the adjacent cylindrical battery is relatively close, and it is easily affected by the temperature of the adjacent cylindrical battery, which will affect the temperature acquisition accuracy.

[0025] Based on the applicant's research on the installation location of the temperature acquisition device, and the impact of different installation locations on the installation strength and temperature acquisition accuracy, this application discloses a battery pack that enables the installation location of the temperature acquisition device to balance installation strength and temperature acquisition accuracy.

[0026] like Figure 1 and Figure 2 As shown, the battery pack disclosed in this application embodiment includes a base plate 101 and a plurality of cylindrical batteries 200 disposed on the base plate 101. The axial direction of the cylindrical batteries 200 is parallel to the plane of the base plate 101, that is, the cylindrical batteries 200 are arranged on the base plate 101 at a lying installation angle. Exemplarily, the battery pack may include a battery housing 100, and the base plate of the battery housing 100 is the base plate of the battery pack. It should be noted that the battery pack may also be without a battery housing 100, and the cylindrical batteries 200 may be directly arranged in the corresponding space of the vehicle chassis, in which case the base plate of the battery pack is part of the vehicle. The cylindrical batteries 200 are not limited to lithium batteries (such as ternary lithium batteries, lithium iron phosphate batteries), sodium batteries, etc.; any battery with temperature measurement requirements can be applied to the solution disclosed in this embodiment.

[0027] like Figure 2 , Figure 4 and Figure 5 As shown, the cylindrical battery 200 has at least two layers along the direction perpendicular to the base plate 101. When multiple layers of cylindrical batteries 200 are provided, the bottommost cylindrical battery 200 can be arranged on the base plate 101, and the other layers of cylindrical batteries 200 are stacked upwards along the direction perpendicular to the base plate 101. A support partition 102 can be provided between two adjacent layers of cylindrical batteries 200. The support partition 102 is used to separate the two adjacent layers of cylindrical batteries 200 and to support the upper layer of cylindrical batteries 200.

[0028] The support spacer 102 can be a corrugated plate, that is, the support spacer 102 has spaced and continuous upwardly concave curved grooves and downwardly concave curved grooves. The cylindrical batteries 200 on the lower side of the support spacer 102 are arranged sequentially in the downwardly concave curved grooves of the support spacer 102, while the cylindrical batteries 200 on the upper side of the support spacer 102 are arranged sequentially in the upwardly concave curved grooves of the support spacer 102.

[0029] The base plate 101 is used to support the cylindrical battery 200. The base plate 101 can be made of metal materials such as aluminum, aluminum alloy, copper, iron, and stainless steel. It should be noted that those skilled in the art can also choose other materials for the base plate 101 according to actual needs, and are not limited to the materials listed above.

[0030] At least one cylindrical battery 200 has a temperature sensing device 500 disposed on the outer peripheral surface of its casing. Those skilled in the art can select which cylindrical batteries 200 in the battery pack require the temperature sensing device 500 based on their needs. A cylindrical battery 200 typically includes a battery casing and battery cells disposed within the casing. The battery casing includes two opposing end faces and an outer peripheral surface located between the two end faces. The temperature sensing device 500 is disposed on the outer peripheral surface of the battery casing.

[0031] To reflect the temperature of the battery pack, multiple temperature acquisition devices 500 can be set up and distributed as widely as possible to prevent them from being concentrated in a small area. The temperature acquisition devices 500 are used to collect the temperature of the cylindrical battery 200's casing, thereby reflecting the temperature of the internal cells of the cylindrical battery 200. The battery temperature is then transmitted to the battery management system to monitor the overall battery temperature of the battery pack, prevent abnormal battery temperatures, and promptly issue an alarm when abnormal battery temperatures occur.

[0032] Temperature acquisition devices 500 generally include a thermistor, typically packaged in a form similar to a metal film resistor, a small ceramic capacitor, or a surface-mount solder joint; these are commonly referred to as thermistors. Some thermistors, such as NTC (Negative Temperature Coefficient) thermistors, exhibit a decrease in resistance as temperature increases. The thermistor may also be surrounded by a sealant and may have a protective structure consisting of a flexible and / or rigid metal support.

[0033] The temperature acquisition device 500 can be an NTC sensor or any other temperature measuring device capable of detecting the temperature of the cylindrical battery 200. This embodiment does not limit the specific type of the temperature acquisition device 500. For example... Figure 2 and Figure 3 As shown, the line connecting the temperature acquisition device 500 to the center of the cylindrical battery 200 it is located on is the installation position connection line 201. Specifically, the area where the temperature acquisition device 500 is located serves as one endpoint of the installation position connection line 201, which can be connected to any point within that area. Alternatively, the midpoint of the area can also be used as one endpoint. Those skilled in the art can also select other locations of the temperature acquisition device 500 as endpoints of the installation position connection line 201 as needed, and are not limited to the midpoint of the area where the temperature acquisition device 500 is located.

[0034] Those skilled in the art will understand that the center of the cylindrical battery 200 needs to be located on the same cross-section of the cylindrical battery 200 (i.e., the cross-section perpendicular to the axis of the cylindrical battery 200) as the midpoint of the area where the temperature acquisition device 500 is located; in other words, the installation position line 201 is perpendicular to the axis of the cylindrical battery 200.

[0035] For ease of understanding, the cylindrical battery 200 closest to the base plate 101 is defined as the first cylindrical battery. The cylindrical battery 200 furthest from the base plate 101 is defined as the second cylindrical battery. When the number of cylindrical battery layers 200 exceeds two, in addition to the first and second cylindrical batteries, several intermediate cylindrical batteries are also included. Since the intermediate cylindrical batteries can only be installed in the gap between the three cylindrical batteries 200 of the upper and lower layers, they are not within the scope of the structural design of this embodiment. That is, the intermediate cylindrical batteries can be set above the reference position connection line 202 or below the reference position connection line 202 as needed.

[0036] When there are two or more cylindrical cells 200 in a direction perpendicular to the base plate 101, there are more cylindrical cells 200 in the gap between adjacent layers of cylindrical cells 200. Usually, adjacent layers of cylindrical cells 200 are staggered, that is, the lower layer of cylindrical cells 200 is placed between the two upper layers of cylindrical cells 200; the upper layer of cylindrical cells 200 is placed between the two lower layers of cylindrical cells 200.

[0037] This arrangement means that the gap between two adjacent cylindrical battery layers 200 is usually surrounded by three cylindrical batteries 200. For example, the gap can be surrounded by two upper cylindrical batteries 200 and one lower cylindrical battery 200, or by one upper cylindrical battery 200 and two lower cylindrical batteries 200. This makes it difficult for heat dissipation to occur around the gap, and the heat generated is relatively large. Therefore, if the temperature acquisition device 500 is placed in the gap between two cylindrical batteries 200, the temperature value of the target cylindrical battery is easily affected by the temperature of the other two cylindrical batteries 200 around it, resulting in poor temperature measurement accuracy.

[0038] To ensure the accuracy of temperature acquisition, the temperature acquisition device 500 should be placed away from the two cylindrical batteries 200 as much as possible.

[0039] The angle between the installation position line 201 and the plane containing the base plate 101 is the installation angle (i.e., the installation angle of the temperature acquisition device 500). This installation angle is denoted as a°, and the range of a° is 5° < a < 85°. For example, a° can be 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, etc. Those skilled in the art can select the specific installation angle according to actual needs.

[0040] When the cylindrical battery 200 is in a vibrating environment, if the mounting angle is too large, it will experience a greater vertical inertial force. In this case, when the cylindrical battery 200 vibrates up and down, the inertial force of the temperature acquisition device 500 will cause the connection to experience a peeling force perpendicular to the circumference of the cylindrical battery 200, making it more likely to be pulled apart. If the mounting angle is too small, although the peeling force is smaller and the connection is less likely to be pulled apart, the closer proximity to adjacent cylindrical batteries 200 makes it more susceptible to the temperature influence of neighboring cylindrical batteries 200, affecting the accuracy of temperature acquisition.

[0041] The battery pack disclosed in this application has at least two layers of cylindrical batteries 200 along a direction perpendicular to the base plate 101, with adjacent layers of cylindrical batteries 200 staggered. A temperature acquisition device 500 is provided on the outer peripheral surface of the cylindrical battery 200. The line connecting the temperature acquisition device 500 and the center of the cylindrical battery 200 is the installation position line 201. The angle between the installation position line 201 and the plane of the base plate 101 is controlled between 5° and 85°, which can reduce the peeling force at the connection caused by vibration load and reduce the temperature influence of adjacent cylindrical batteries, thereby improving the temperature acquisition accuracy.

[0042] Furthermore, the temperature acquisition device on the first cylindrical battery is positioned on the side closer to the base plate 101, while the temperature acquisition device 500 on the second cylindrical battery is positioned on the side farther from the base plate 101. That is, the temperature acquisition device 500 is not positioned between the two cylindrical batteries 200 to ensure the accuracy of the collected temperature.

[0043] In a specific embodiment of this application, the temperature acquisition device 500 is adhesively bonded to the outer peripheral surface of the cylindrical battery 200 casing by an adhesive layer, and the thickness of the adhesive layer is b millimeters, specifically 0.1 mm to 2 mm (i.e., b can be selected between 0.1 and 2, including endpoint values). Then a / b satisfies the condition: 20 ≤ a / b ≤ 115, where both a and b are unitless.

[0044] It should be noted that the adhesive material for bonding the temperature acquisition device 500 can be epoxy resin, silicone, polyurethane, thermally conductive silicone, glass glue, etc., or other adhesives can be selected, as long as they can achieve the bonding and fixation of the temperature acquisition device 500.

[0045] Those skilled in the art will understand that a greater adhesive layer thickness (i.e., a larger b) results in a stronger bond and greater resistance to peeling of the temperature acquisition device 500. When a larger adhesive layer thickness is used to bond the temperature acquisition device 500, a larger mounting angle can be selected (i.e., a larger angle value is chosen). Choosing a larger mounting angle for the temperature acquisition device 500 reduces the influence of temperature from other adjacent cylindrical batteries 200, improving the accuracy of temperature acquisition. The greater peeling force resulting from a larger mounting angle can be offset by increasing the adhesive layer thickness.

[0046] The smaller the adhesive layer thickness (i.e., the smaller b), the weaker the bonding strength of the temperature acquisition device 500 and the lower its resistance to peeling. When a smaller adhesive layer thickness is used to bond the temperature acquisition device 500, a smaller mounting angle can be selected (i.e., a is a smaller angle value). Selecting a smaller mounting angle for the temperature acquisition device 500 can reduce the peeling force perpendicular to the circumferential surface of the cylindrical battery 200, thus compensating for the risk of lower peeling resistance due to the smaller adhesive layer thickness.

[0047] like Figure 1 and Figure 2 As shown in a specific embodiment of this application, the battery pack includes at least one column of cylindrical batteries, and the cylindrical battery column includes a plurality of stacked cylindrical batteries 200, the stacking direction of the cylindrical battery column being perpendicular to the axial direction of the cylindrical batteries 200.

[0048] like Figure 3 As shown, the line connecting the centers of each cylindrical battery 200 in the cylindrical battery array where the temperature acquisition device 500 is located is the reference position line 202. When the stacking direction of the cylindrical battery array is perpendicular to the axial direction of the cylindrical battery 200, the line connecting the centers of each cylindrical battery 200 in the cylindrical battery array is parallel to the plane where the base plate 101 is located, that is, the plane containing the axis of each cylindrical battery 200 in the cylindrical battery array is parallel to the plane where the base plate 101 is located.

[0049] Consequently, the angle between the installation position line 201 and the reference position line 202 becomes the installation angle. When the temperature acquisition device 500 is bonded and installed, if the plane where the base plate 101 is located is not easily used as a reference for determining the installation angle, the reference position line 202 can be obtained by connecting the centers of two adjacent cylindrical batteries 200, and the installation position of the temperature acquisition device 500 can be obtained by using the reference position line 202 as a reference.

[0050] The temperature acquisition device 500 can be fixed on the side of the cylindrical battery 200 near the base plate 101, or on the side of the cylindrical battery 200 away from the base plate 101. This embodiment does not limit the installation position of the temperature acquisition device 500 to whether it is located above or below the reference position line 202.

[0051] When the cylindrical battery 200 is a single layer along a direction perpendicular to the base plate 101, if the temperature acquisition device 500 is positioned below the reference position line 202, making the temperature acquisition device 500 relatively close to the base plate 101, the base plate 101 typically has superior heat dissipation conditions. Therefore, the temperature on the side of the cylindrical battery 200 that is in contact with the base plate 101 is lower than other locations. If the temperature acquisition device 500 is positioned below the reference position line 202, the temperature value acquired by the temperature acquisition device 500 is easily affected by the base plate 101, leading to inaccurate data acquisition.

[0052] The temperature acquisition device 500 on the first cylindrical battery is positioned near the base plate 101. Although the base plate 101 has strong heat dissipation capabilities, placing the temperature acquisition device 500 near the base plate 101 will result in a temperature value that is lower than the actual temperature of the first cylindrical battery. However, when multiple layers of cylindrical batteries are arranged, the heat dissipation effect of the base plate 101 has a relatively small impact on the temperature reduction of the cylindrical batteries 200 due to the large number of cylindrical batteries 200 arranged in the entire space. Therefore, even if the temperature acquisition device 500 on the first cylindrical battery is positioned near the base plate 101, the difference between the temperature value acquired by the temperature acquisition device 500 and the actual temperature of the cylindrical battery 200 is negligible. In contrast, if the temperature acquisition device 500 on the first cylindrical battery is positioned away from the base plate 101, the upper side of the reference position connection line 202 will be affected by the temperature of the other two cylindrical batteries 200. Therefore, when positioned away from the base plate 101, the temperature value acquired will be higher than the actual temperature value of the cylindrical battery 200 being detected.

[0053] The temperature acquisition device 500 on the second cylindrical battery is positioned on the side away from the base plate 101. Specifically, the temperature acquisition device 500 on the uppermost cylindrical battery 200 is positioned above the reference position line 202. This avoids placing the temperature acquisition device 500 within the gap formed by the three cylindrical batteries 200, reducing the influence of other cylindrical batteries 200 and improving the accuracy of temperature acquisition.

[0054] When the cylindrical battery 200 has at least two layers, the mounting angle α of the temperature acquisition device 500 on the first cylindrical battery ranges from 30° to 75°. That is, the mounting angle of the temperature acquisition device 500 on the bottommost cylindrical battery 200 can be selected to be smaller, keeping the temperature acquisition device 500 as far away from the base plate 101 as possible to reduce the risk of collision between the base plate 101 and the temperature acquisition device 500 during vibration. At the same time, appropriately selecting a smaller mounting angle allows the temperature acquisition device 500 to be relatively close to the adjacent cylindrical batteries 200, also reducing the possibility of the base plate 101's heat dissipation capacity causing the collected temperature value to be too low.

[0055] The mounting angle 'a' of the temperature acquisition device 500 on the second cylindrical battery ranges from 30° to 85°. This means that the temperature acquisition device 500 on the uppermost cylindrical battery 200 can have a larger mounting angle, keeping it as far away as possible from adjacent cylindrical batteries 200. Due to the multiple layers of cylindrical batteries 200, heat dissipation is poor, resulting in generally higher temperatures within the battery pack's mounting space. Because hot air rises, the temperature of the upper cylindrical batteries 200 will be slightly higher than that of the lower ones. Therefore, selecting a larger mounting angle allows the temperature acquisition device 500 to be kept as far away as possible from other cylindrical batteries 200, while also being closer to the battery pack cover, reducing the impact of poor heat dissipation and heat accumulation. This allows the temperature to more closely approximate the actual temperature of the measured cylindrical battery 200, improving detection accuracy.

[0056] When the cylindrical battery 200 has at least two layers, the temperature acquisition device 500 on the first cylindrical battery satisfies the condition: 20 ≤ a / b ≤ 90; the temperature acquisition device 500 on the second cylindrical battery satisfies the condition: 20 ≤ a / b ≤ 95. It should be noted that the adhesive layer thickness value bmm for the first and second cylindrical batteries can be the same or different. Correspondingly, the mounting angle value a° for the first and second cylindrical batteries can be the same or different.

[0057] Because the temperature acquisition device 500 on the first cylindrical battery can have a smaller installation angle value 'a' compared to the temperature acquisition device 500 on the second cylindrical battery, the a / b value of the first cylindrical battery can also be designed to be smaller than that of the second cylindrical battery. It should be noted that the first and second cylindrical batteries can also have the same a / b value.

[0058] Those skilled in the art will understand that the temperature acquisition device 500 can be directly bonded to the outer peripheral surface of the cylindrical battery 200 casing, or it can be bonded to the outer peripheral surface of the cylindrical battery 200 casing using a fastener. The fastener can provide protection for the temperature acquisition device 500 and also facilitates the application of adhesive to achieve bonding with the outer peripheral surface of the cylindrical battery 200 casing.

[0059] The temperature acquisition device 500 is fixed to the outer peripheral surface of the cylindrical battery 200 casing by an adhesive layer. When at least part of the adhesive layer is located between the temperature acquisition device 500 and the cylindrical battery 200, since the adhesive layer needs to be applied to the outer peripheral surface of the cylindrical battery 200 casing first, and the adhesive layer is in a liquid state before curing, it tends to flow downward along the outer peripheral surface of the cylindrical battery 200 casing under the action of gravity. Therefore, the mounting angle α° can be appropriately increased. In this embodiment, the mounting angle can be set to a range of 10°~85° (i.e., α° is selected within the range of 10°~85°). Choosing a larger angle value for the mounting angle allows the adhesive layer to maintain a distance from the adjacent cylindrical battery 200 even if it flows downward, reducing the temperature influence of the adjacent cylindrical battery 200.

[0060] When at least part of the adhesive layer is located on the side of the temperature acquisition device 500 away from the cylindrical battery 200, the adhesive layer can isolate part of the temperature influence of adjacent cylindrical batteries 200. In order to improve the bonding strength, the installation angle value a° can be appropriately reduced. In this embodiment, the installation angle of the temperature acquisition device 500 is set to a range of 5° to 75° (i.e., a° is selected within the range of 5° to 75°). This allows the temperature influence of other cylindrical batteries 200 to be reduced even if the temperature acquisition device 500 is relatively close to the adjacent cylindrical battery 200, due to the heat insulation effect of the adhesive layer. Moreover, by selecting a smaller installation angle value, the peeling force at the joint caused by vibration load can be reduced, thereby improving the fixing reliability of the temperature acquisition device 500.

[0061] The cylindrical battery 200 includes a battery casing and a battery cell disposed within the battery casing. The battery casing includes two oppositely disposed end faces and an outer peripheral surface of the casing located between the two end faces. The diameter of the end faces of the battery casing is not less than 40 mm, such that the area of ​​the end faces of the battery casing is not less than 400 mm². 2 The larger the diameter of the cylindrical battery 200, the greater its risk of thermal runaway expansion and vibration, making it crucial to carefully select the location of the temperature acquisition device 500 on the cylindrical battery 200. In this embodiment, the range of a° is controlled between 5° and 70°, and the range of a / b is controlled between 20 and 90. Experimental verification has shown that this reduces the peeling force at the connection point of the temperature acquisition device 500 caused by vibration loads, reduces the temperature influence of adjacent cylindrical batteries 200, improves temperature acquisition accuracy, prevents abnormal battery pack temperatures, and provides timely alarms when abnormal temperatures occur.

[0062] A temperature difference test is set up, and the temperature difference test process is as follows: For different embodiments and comparative examples, three cylindrical batteries of the same model were taken. Two of the cylindrical batteries were stacked in a direction perpendicular to the axial direction of the cylindrical batteries. Temperature acquisition devices were installed on the outer peripheral surface of the casing of one of the stacked cylindrical batteries and the outer peripheral surface of the casing of the other separately set cylindrical battery according to the installation angle value a° in Table 1. Except for the installation angle value a°, all other conditions were the same.

[0063] The temperature acquisition devices in the two stacked cylindrical batteries are installed on the side of one cylindrical battery closest to the other. The two stacked cylindrical batteries and the standalone cylindrical battery are discharged at a 1C rate to 0% SOC (State of Charge). After resting for 10 minutes, they are charged at a 1C rate to 100% SOC. After resting for 10 minutes, they are discharged again at a 1C rate to 0% SOC. The real-time temperature of the two cylindrical batteries with the temperature acquisition devices is recorded during the charging and discharging process, and a charge-discharge temperature curve is plotted. The temperature difference between the two cylindrical batteries with the temperature acquisition devices at the same time interval is calculated based on the curve. If the absolute value of the maximum temperature difference is greater than or equal to 2℃, it is considered unqualified; if the absolute value of the maximum temperature difference is less than 2℃, it is considered qualified. Specific test results are shown in Table 1 below.

[0064] A fixed strength test is set up, and the fixed strength test procedure is as follows: For different embodiments and comparative examples, 50 cylindrical batteries of the same model were taken, and the 50 cylindrical batteries were fixed on an aluminum alloy plate. The temperature acquisition device was installed on the outer circumferential surface of the casing of the 50 cylindrical batteries according to the installation angle value a° in Table 1. Except for the installation angle value a°, all other conditions were the same.

[0065] Fifty cylindrical batteries were placed in an electromagnetic vibration testing machine (MSK-TE917) and subjected to vibration testing according to standard GB / T 31467.3-2015. The vibration test was conducted in three directions: starting with the z-axis, then the y-axis, and finally the x-axis. The test time for each direction was 21 hours. Two hours after the vibration test was completed, the surface temperature acquisition devices of the 50 cylindrical batteries were observed to see if they had peeled off, and the number of peeled cylindrical batteries was calculated. The peeling rate was calculated using the formula: Peeling rate = (Number of peeled cylindrical batteries / Total number of cylindrical batteries) × 100%. The specific results are shown in Table 1 below. If the peeling rate is greater than 5%, it is considered unqualified; if the peeling rate is less than or equal to 5%, it is considered qualified.

[0066] Table 1. Comparison of temperature difference and peeling rate between different embodiments and comparative examples.

[0067] A comparison of the experimental data from Examples 1-12 and Comparative Examples 1-2 reveals that when the installation angle α° of the temperature acquisition device on the outer circumferential surface of the cylindrical battery casing is 4°, the temperature difference is 2.14℃. Although the peeling rate is only 2%, the temperature difference exceeds 2℃, resulting in excessive temperature measurement error and affecting the accuracy of temperature measurement. When the installation angle α° of the temperature acquisition device on the outer circumferential surface of the cylindrical battery casing is 86°, the peeling rate is 6%. Although the temperature difference is only 0.18℃, the peeling rate exceeds 5%, leading to insufficient bonding strength of the cylindrical battery and making it prone to detachment under vibration.

[0068] When the installation angle (a°) of the temperature acquisition device on the outer circumference of the cylindrical battery casing is within the range of 5° to 85°, the temperature difference is less than 2°C, and the peeling rate is less than 5%. The temperature acquisition device has good accuracy in acquiring temperature, and the fixing strength between the temperature acquisition device and the cylindrical battery is good, making peeling less likely.

[0069] Another temperature difference test is set up, and the temperature difference test procedure is as follows: For different embodiments and comparative examples, three identical cylindrical batteries were used. Two of the cylindrical batteries were stacked perpendicular to their axial direction. The temperature acquisition device was attached to the outer circumferential surface of the casing of one of the stacked cylindrical batteries and the outer circumferential surface of the casing of the other separately mounted cylindrical battery using adhesive. The values ​​of the mounting angle 'a°' and the thickness of the adhesive layer 'bmm' are shown in Table 2 below. Except for the mounting angle 'a°' and the thickness of the adhesive layer 'bmm', all other conditions were the same.

[0070] The temperature acquisition devices in the two stacked cylindrical batteries were installed on the side of one battery closest to the other. The two stacked cylindrical batteries and the standalone cylindrical battery were discharged at a 1C rate to 0% SOC. After a 10-minute rest period, they were charged at a 1C rate to 100% SOC. After a 10-minute rest period, they were discharged again at a 1C rate to 0% SOC. The real-time temperatures of the two batteries with the temperature acquisition devices were recorded during the charging and discharging process, and a charge-discharge temperature curve was plotted. The temperature difference between the two batteries at the same time interval was calculated based on the curve. If the absolute value of the maximum temperature difference was greater than or equal to 2℃, the test was considered unqualified; if the absolute value of the maximum temperature difference was less than 2℃, the test was considered qualified. Specific test results are shown in Table 2 below.

[0071] Another fixed strength test is set up, and the fixed strength test procedure is as follows: For different embodiments and comparative examples, 50 cylindrical batteries of the same model were taken from each. The 50 cylindrical batteries were fixed to an aluminum alloy plate, and the temperature acquisition device was installed on the outer circumferential surface of the battery casing using adhesive (i.e., a glue layer). The values ​​of the installation angle 'a°' of the temperature acquisition device and the thickness 'bmm' of the adhesive (i.e., glue layer) are shown in Table 2 below. Except for the installation angle 'a°' and the glue layer thickness 'bmm', all other conditions were the same.

[0072] Fifty cylindrical batteries were placed in an electromagnetic vibration testing machine (MSK-TE917) and subjected to vibration testing according to standard GB / T 31467.3-2015. The vibration test was conducted in three directions: starting from the z-axis, then the y-axis, and finally the x-axis. The test time for each direction was 21 hours. Two hours after the vibration test was completed, the surface temperature acquisition devices of the 50 cylindrical batteries were observed to see if they had peeled off, and the number of peeled cylindrical batteries was calculated. The peeling rate was calculated using the formula: Peeling rate = (Number of peeled cylindrical batteries / Total number of cylindrical batteries) × 100%. The specific results are shown in Table 2 below. If the peeling rate is greater than 5%, it is considered unqualified; if the peeling rate is less than or equal to 5%, it is considered qualified.

[0073] Table 2. Comparison of temperature difference and peeling rate between different embodiments and comparative examples.

[0074] A comparison of the experimental data from Examples 1-21 with those from Comparative Examples 1-6 reveals that when a / b is less than 20, such as in Comparative Examples 1, 3, and 6, the measured temperature difference exceeds 2°C. Even though the values ​​of a and b in Comparative Example 1 meet the requirements, the temperature measurement error still exceeds the standard, which will affect the accuracy of the temperature measurement.

[0075] When a / b is greater than 115, such as in Comparative Examples 2, 4 and 5, the measured peeling rate all exceeded 5%. Even though the values ​​of a and b in Comparative Example 2 met the requirements, the fixation strength was still insufficient, and the sample was prone to falling off under vibration.

[0076] The experimental data from Examples 1 to 21 show that when a / b is selected within the range of 20 to 115, the temperature acquisition device has good accuracy in acquiring temperature, and the fixing strength between the temperature acquisition device and the cylindrical battery is good, making it less likely to peel off from the cylindrical battery. The experimental data from Comparative Examples 5 and 6 show that when b is out of range, if the b value is too small, it will lead to a decrease in fixing strength, and if the b value is too large, it will affect the accuracy of temperature acquisition.

[0077] like Figure 1As shown in a specific embodiment of this application, the battery casing includes two oppositely disposed end faces and an outer peripheral surface of the casing located between the two end faces. The battery casing has a battery current output terminal for current output. The battery current output terminal can be the metal casing of a cylindrical battery (i.e., the end face of the battery casing) or an electrode assembly fixed to the casing (i.e., an electrode assembly disposed on the end face). The battery current output terminals of the two cylindrical batteries 200 are electrically connected through a conductive element 300.

[0078] When the battery current output terminal is a terminal assembly, the terminal assembly generally includes a positive terminal assembly and a negative terminal assembly. When two cylindrical batteries 200 are connected in series, the conductive element 300 needs to electrically connect the positive terminal assembly of one cylindrical battery 200 and the negative terminal assembly of the other cylindrical battery 200 respectively. When two cylindrical batteries 200 are connected in parallel, the conductive element 300 needs to electrically connect the terminal assemblies of the same polarity of the two cylindrical batteries 200 respectively.

[0079] The battery cell has a cell output terminal, which typically includes a positive electrode tab and a negative electrode tab. The positive electrode tab is electrically connected to the positive terminal assembly of the battery casing, and the negative electrode tab is electrically connected to the negative terminal assembly of the battery casing.

[0080] The battery cell is the core component of a cylindrical battery 200, consisting of a positive electrode, a negative electrode, a separator, and an electrolyte. The positive electrode is typically made of materials such as lithium cobalt oxide, lithium manganese oxide, or lithium iron phosphate; the negative electrode is generally made of materials such as graphite; the separator is a thin film with a microporous structure located between the positive and negative electrodes, serving to isolate them and prevent short circuits; the electrolyte is an organic solution containing lithium salts, responsible for conducting lithium ions between the positive and negative electrodes.

[0081] The tabs (positive and negative tabs) are typically thin metal sheets or wires extending from the positive and negative electrode plates of the battery cell. One end of the tab is connected to the electrode plate inside the battery cell, and the other end is connected to the terminal assembly on the battery casing. The function of the tabs is to draw the current from inside the battery cell and collect it on the terminal assembly, thus connecting the battery cell to the external circuit.

[0082] The battery casing is the outermost protective structure of the cylindrical battery 200, serving to house and protect internal components (such as the battery cells). The main function of the battery casing is to prevent harmful substances such as moisture and oxygen from entering the interior, avoiding damage to the battery cells, protecting the internal battery cells and other components from external physical impacts and chemical corrosion, and ensuring the safety and stability of the cylindrical battery 200.

[0083] The terminal assembly (positive terminal assembly and negative terminal assembly) is an important component connecting the cylindrical battery 200 to the external circuit. It can transfer the electrical energy generated by the cell to the external circuit, and at the same time introduce the electrical energy of the external circuit into the cell for charging, thus acting as a bridge for current conduction.

[0084] like Figures 6-8 As shown, the temperature acquisition device 500 is arranged on the outer peripheral surface of the cylindrical battery 200. Therefore, by setting the axial position of the temperature acquisition device 500 on the outer peripheral surface of the casing, the distance to the conductive component 300 (i.e., the distance to the end face where the battery current output terminal is located) can be changed.

[0085] The minimum distance X between the temperature acquisition device 500 and the end face of the battery current output terminal of the battery casing is defined as X. The end face of the cylindrical battery 200 where the battery current output terminal is located (i.e., the power connection terminal of the battery casing; for ease of understanding, the power connection terminal will be used as the end face of the cylindrical battery 200 where the battery current output terminal is located in the following text) is not a plane; it also has corresponding structures such as terminal post assemblies. Therefore, for ease of understanding, the minimum distance between the temperature acquisition device 500 and the power connection terminal of the cylindrical battery 200 is taken as the axial position reference for the temperature acquisition device 500. Typically, the minimum distance between the temperature acquisition device 500 and the power connection terminal of the cylindrical battery 200 is the surface of the cover plate of the power connection terminal of the battery casing.

[0086] The length of the battery casing is L, which is the minimum distance between the two end faces of the battery casing. Therefore, 0.1 ≤ X / L ≤ 0.5. In this embodiment, by also using the length L of the battery casing as a condition for constraining the temperature acquisition device 500, the temperature acquisition device 500 can select the corresponding X parameter according to cylindrical batteries 200 of different lengths to obtain better acquisition accuracy.

[0087] In this embodiment, the ratio of the minimum distance X between the contact end of the cylindrical battery 200 and the length L of the battery casing is used as a reference for the placement of the temperature acquisition device 500. This reduces the temperature impact of the conductive component 300 while facilitating the arrangement of the temperature acquisition device 500. This embodiment controls the ratio of the distance X between the temperature acquisition device 500 and the contact end of the battery casing to the length L of the battery casing within the range of 0.1 to 0.5, thereby reducing the impact of the high-temperature environment on the contact end side on the temperature acquisition device 500. The temperature value acquired by the temperature acquisition device 500 in this application is closer to the temperature of the cylindrical battery 200 cell itself, improving the accuracy of temperature acquisition. This allows for a more suitable over-temperature protection and temperature control strategy in terms of thermal runaway monitoring and thermal management control.

[0088] When the condition 0.1≤X / L≤0.5 is met, the temperature acquisition device 500 is adhesively bonded to the outer circumferential surface of the cylindrical battery 200 casing with an adhesive layer of thickness b millimeters, and the range of a / b is 20~80. In this embodiment, by controlling the temperature acquisition device 500 in the above-mentioned position in the axial direction of the cylindrical battery 200, and controlling a / b within the range of 20~80, the influence of heat generated at the battery current output terminal on the temperature acquisition device 500 can be avoided, which would prevent the accurate measurement of the battery casing temperature and thus the inability to reflect the relative true temperature of the internal cells. Furthermore, the bonding strength is also improved.

[0089] When the condition 0.3≤X / L≤0.5 is met, the temperature acquisition device 500 is glued to the outer peripheral surface of the cylindrical battery 200 casing by an adhesive layer with a thickness of b millimeters, and the range of a / b is 20~70. In this embodiment, the temperature acquisition device 500 is controlled at the above position in the axial direction of the cylindrical battery 200, that is, it can be closer to the middle position in the axial direction of the cylindrical battery 200 compared to the above embodiment. At the same time, controlling a / b in the range of 20~70 can further reduce the impact of heat generation at the battery current output terminal on the temperature measurement accuracy. Moreover, the closer it is to the middle position in the axial direction of the cylindrical battery 200, the higher the fixing strength of the temperature acquisition device 500.

[0090] The battery cell has a cell current output terminal, which is electrically connected to the battery current output terminal. Both the cell current output terminal and the battery current output terminal are located on one side of the cylindrical battery 200 along its axial direction. When the positive and negative electrode assemblies (i.e., the battery current output terminal) are located at the same end of the battery casing, and the positive and negative electrode tabs (i.e., the cell current output terminal) are also located near the connection point, the temperature near the connection point of the battery casing will be higher. Therefore, increasing the distance between the temperature acquisition device 500 and the connection point of the battery casing helps reduce the impact of high temperatures in the connection point area, facilitates the measurement of the actual temperature of the battery cell itself, and improves the accuracy of temperature acquisition. Based on this, in this embodiment, controlling X / L within the range of 0.2 to 0.4 can reduce the impact of high temperatures in the connection point area on temperature measurement accuracy.

[0091] The minimum distance X between the temperature acquisition device 500 and the power connection terminal of the battery casing satisfies: 15mm ≤ X ≤ 95mm; and / or, the length L of the battery casing satisfies: 70mm ≤ L ≤ 200mm. Based on X / L being within the range of 0.1 to 0.5, X can be selected between 15mm and 95mm. For example, X can be selected as 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, etc., all of which can achieve low temperature measurement deviation and improve temperature measurement accuracy. It should be noted that the specific X value mentioned above is only an example, and those skilled in the art can arbitrarily select a value within the range of 15 to 95mm based on the above example and according to requirements.

[0092] The technical solution disclosed in this embodiment is applicable to cylindrical batteries with a battery casing length L between 70mm and 200mm. It should be noted that for cylindrical batteries with a casing length outside the above range, a low temperature measurement deviation can also be obtained by selecting X / L within the range of 0.1 to 0.5. For example, L can be selected as 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, etc. It should be noted that the specific L values ​​mentioned above are only examples, and those skilled in the art can arbitrarily select values ​​within the range of 70mm to 200mm based on the above examples and their requirements.

[0093] In one specific embodiment of this application, a conductive element 300 is provided at one end of the cylindrical battery 200 where the battery current output terminal is located, and a heat exchange element 400 is provided at the other end of the cylindrical battery 200. Because of the heat exchange element 400, when the temperature of the cylindrical battery 200 rises to a level that triggers the activation of the heat exchange element 400, the heat exchange element 400 conducts cooling energy from the heat exchange end of the cylindrical battery 200 (the heat exchange end being the end of the cylindrical battery 200 closest to the heat exchange element 400) to the cylindrical battery 200. Therefore, the closer the cylindrical battery 200 is to the heat exchange element 400, the lower its temperature.

[0094] Therefore, when selecting the axial position of the temperature acquisition device 500, in addition to considering the temperature influence of the conductive component 300, the temperature influence of the heat exchanger 400 also needs to be considered. In this embodiment, the range of X / L can be set to: 0.3≤X / L≤0.5. That is, when the battery pack is equipped with a heat exchanger 400, the location of the temperature acquisition device 500 should be selected in the area close to the conductive component 300, relative to a battery pack without a heat exchanger 400.

[0095] When a cylindrical battery 200 has a heat exchanger 400 at one end and a conductive element 300 at the other end, the location of the temperature acquisition device 500 on the outer surface of the cylindrical battery 200—whether it's closer to the heat exchanger 400 or the conductive element 300—will affect the accuracy of its temperature measurement. In this embodiment, the temperature acquisition device 500 is closer to the conductive element 300 than the heat exchanger 400 to prevent the acquired temperature value from being lower than the actual temperature of the cylindrical battery 200. This would prevent the over-temperature protection from being activated in time if there is a risk of thermal runaway in the battery cell; or, when the cylindrical battery 200 needs cooling, the thermal management system could not be activated in time.

[0096] The heat exchanger 400 can be bonded to the cylindrical battery 200 with thermally conductive adhesive, and at least part of the thermally conductive adhesive is located between two adjacent cylindrical batteries 200. This allows the heat exchanger 400 to conduct more cold energy to the cylindrical battery 200, thereby improving the cooling effect on the cylindrical battery 200.

[0097] In one specific embodiment of this application, there are at least two temperature acquisition devices 500, wherein the angle difference between the installation angles of the multiple temperature acquisition devices 500 is no greater than 5°, that is, to ensure that the installation angles of each temperature acquisition device 500 are the same or close as much as possible.

[0098] A temperature measurement experiment was set up. A positive electrode, a negative electrode, and a separator were used to make a battery cell. The main material of the positive electrode was lithium iron phosphate, and the main material of the negative electrode was artificial graphite. The battery cell was placed in a battery casing of different lengths L as shown in Table 3, and the length of the battery cell was 0.9L (that is, the length of the battery cell is related to the length L of the battery casing). Then, after setting a first temperature acquisition device between the battery cell and the battery casing, the battery was packaged, injected with electrolyte, formed, and capacitated to make a cylindrical battery.

[0099] All cylindrical batteries are identical except for L. Two identical cylindrical batteries are connected in series with a conductive component. A second temperature acquisition device is installed on the surface of one battery casing. The cylindrical battery is discharged to 2.8V at 0.33C, left to stand for 10 minutes, and then charged to 3.65V at 0.33C. This cycle is repeated 100 times. The maximum absolute value of the temperature difference collected by the first and second temperature acquisition devices during the cycle is recorded. The installation positions of the first and second temperature acquisition devices are set according to the X values ​​in Table 3, and the first and second temperature acquisition devices are set relative to each other.

[0100] Table 3. Comparison of Temperature Differences between Temperature Values ​​and Actual Temperature Values ​​at Different Locations

[0101] As shown in Table 3, the scheme disclosed in Comparative Example 3 involves installing the second temperature acquisition device at the power terminal of the battery casing, and the length of the cylindrical battery casing is 100mm. Under this structural configuration, the absolute value of the difference between the temperature values ​​measured by the first and second temperature acquisition devices is 2.45℃. Those skilled in the art will understand that if the difference between the temperature value measured by the temperature acquisition device and the actual temperature value of the battery cell exceeds 2℃, it will affect the thermal runaway protection mechanism and the temperature control strategy of the thermal management system.

[0102] Examples 1-17, as well as Comparative Examples 1 and 2, all disclose solutions where the second temperature acquisition device is mounted on the outer surface of the battery casing. Of course, the X, L, and X / L values ​​differ between the different embodiments and comparative examples. It can be seen that although the second temperature acquisition device is mounted on the outer surface of the battery casing, the absolute value of the difference between the temperature values ​​measured by the first and second temperature acquisition devices varies considerably under different data conditions.

[0103] The scheme disclosed in Comparative Example 1 is as follows: X is 60mm, L is 100mm, X / L is 0.6, and the absolute value of the difference between the temperature values ​​collected by the first temperature acquisition device and the second temperature acquisition device is 2.68℃.

[0104] The scheme disclosed in Comparative Example 2 is as follows: X is 16mm, L is 180mm, X / L is 0.09, and the absolute value of the difference between the temperature values ​​collected by the first temperature acquisition device and the second temperature acquisition device is 2.35℃.

[0105] The experimental data disclosed in Comparative Examples 1 and 2 show that placing the second temperature acquisition device too close or too far from the power connection of the battery casing will cause a large deviation between the temperature value detected by the second temperature acquisition device and the actual temperature value (i.e., the temperature value acquired by the first temperature acquisition device), which will exceed 2°C.

[0106] According to the experimental data disclosed in Examples 1-17, even when X is a minimum of 14 mm (Example 14) or a maximum of 100 mm (Example 15), the absolute value of the difference between the temperature values ​​collected by the first temperature acquisition device and the second temperature acquisition device does not exceed 2°C, and even does not exceed 1°C. Even when L is a minimum of 68 mm (Example 16) or a maximum of 205 mm (Example 17), the absolute value of the difference between the temperature values ​​collected by the first temperature acquisition device and the second temperature acquisition device does not exceed 2°C, and even does not exceed 1°C.

[0107] According to the experimental data disclosed in Examples 13 and 17, although X takes different values ​​(36.9 mm in Example 13 and 85 mm in Example 17) and L takes different values ​​(90 mm in Example 13 and 205 mm in Example 17), the value of X / L is 0.41. Therefore, the absolute value of the difference between the temperature values ​​obtained by the first temperature acquisition device and the second temperature acquisition device is relatively close (0.57 in Example 13 and 0.76 in Example 17). In summary, according to the experimental data disclosed in Examples 1-17, the key factor affecting the deviation between the temperature value detected by the second temperature acquisition device and the actual temperature value is X / L.

[0108] This application also discloses a battery pack, which includes a frame, a cover, and a battery assembly as disclosed in the above embodiments. The frame is connected to the base plate 101 of the battery assembly, and the cover is sealed to the frame, so that the cylindrical battery 200 is sealed within the space enclosed by the base plate 101, the cover, and the frame, thereby helping the cylindrical battery 200 resist various harsh environmental conditions, such as dust, moisture, and chemicals. The battery pack disclosed in this application, having the aforementioned battery assembly, possesses all the technical effects of the aforementioned battery assembly, which will not be elaborated upon further here.

[0109] This application also discloses an electrical device that includes the battery pack disclosed in the above embodiments. This electrical device can be an electric vehicle, an electric ship, an aircraft, an energy storage device, etc. Since electric vehicles have a greater risk of vibration than other electrical devices, applying the battery pack disclosed in the above embodiments to electric vehicles can achieve better vibration resistance. The electrical device disclosed in this application, having the aforementioned battery pack, possesses all the technical effects of the aforementioned battery pack, which will not be elaborated upon further here.

[0110] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0111] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0113] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only 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 several improvements and modifications to this application without departing from the principles of this application, 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 device includes a base plate (101) and a plurality of cylindrical batteries (200) disposed on the base plate (101). The axial direction of the cylindrical batteries (200) is parallel to the plane on which the base plate (101) is located. Along the direction perpendicular to the base plate (101), the cylindrical batteries (200) are at least two layers, and the adjacent layers of cylindrical batteries (200) are staggered. The layer of cylindrical batteries (200) closest to the base plate (101) is the first cylindrical battery, and the layer of cylindrical batteries (200) farthest from the base plate (101) is the second cylindrical battery. At least one of the cylindrical batteries (200) has a temperature acquisition device (500) provided on the outer peripheral surface of its casing. The temperature acquisition device (500) on the first cylindrical battery is located on the side closer to the base plate (101), and the temperature acquisition device (500) on the second cylindrical battery is located on the side away from the base plate (101). The line connecting the temperature acquisition device (500) and the center of the cylindrical battery (200) is the installation position line (201). The angle between the installation position line (201) and the plane of the base plate (101) is the installation angle. The angle of the installation angle is a°, and the range of a° is 5°~85°.

2. The battery pack as described in claim 1, characterized in that, The installation angle α° of the temperature acquisition device (500) on the first cylindrical battery ranges from 30° to 75°. And / or, The installation angle α° of the temperature acquisition device (500) on the second cylindrical battery ranges from 30° to 85°.

3. The battery pack as described in claim 1, characterized in that, The temperature acquisition device (500) is glued to the outer circumferential surface of the cylindrical battery (200) casing by an adhesive layer, and the thickness of the adhesive layer is b millimeters; Then a / b satisfies the condition: 20≤a / b≤115.

4. The battery pack as described in claim 3, characterized in that, The thickness b mm of the adhesive layer ranges from 0.1 mm to 2 mm.

5. The battery pack as described in claim 3, characterized in that, The temperature acquisition device (500) on the first cylindrical battery satisfies the condition: 20≤a / b≤90; The temperature acquisition device (500) on the second cylindrical battery satisfies the condition: 20≤a / b≤95.

6. The battery pack as claimed in claim 1, characterized in that, Multiple cylindrical cells (200) are stacked in a direction perpendicular to the axial direction of the cylindrical cells (200) to form a cylindrical cell array; The line connecting the centers of each cylindrical battery (200) in the cylindrical battery array where the temperature acquisition device (500) is located is the reference position line (202). The angle between the line connecting the installation position (201) and the line connecting the reference position (202) is the installation angle.

7. The battery pack according to any one of claims 1-6, characterized in that, The temperature acquisition device (500) is bonded to the outer peripheral surface of the cylindrical battery (200) by an adhesive layer. At least part of the adhesive layer is located between the temperature acquisition device (500) and the cylindrical battery (200). Therefore, the range of the installation angle a° is 10°~85°.

8. The battery pack as claimed in claim 1, characterized in that, The temperature acquisition device (500) is bonded to the outer peripheral surface of the cylindrical battery (200) by an adhesive layer. At least part of the adhesive layer is located on the side of the temperature acquisition device (500) away from the cylindrical battery (200), and the range of the mounting angle a° is 5°~75°.

9. The battery pack as claimed in claim 1, characterized in that, The cylindrical battery (200) includes a battery casing and a battery cell disposed within the battery casing. The battery casing includes two oppositely disposed end faces and an outer peripheral surface of the casing located between the two end faces. The diameter of the end faces of the battery casing is not less than 40 mm. The range of a° is 5°~70°, and the range of a / b is 20~90. The temperature acquisition device (500) is glued to the outer circumferential surface of the cylindrical battery (200) by an adhesive layer, and the thickness of the adhesive layer is b millimeters.

10. The battery pack as claimed in claim 1, characterized in that, The cylindrical battery (200) includes a battery casing and a battery cell disposed within the battery casing. The battery casing includes two oppositely disposed end faces and an outer peripheral surface of the casing located between the two end faces. The battery casing has a battery current output terminal for current output. The minimum distance between the temperature acquisition device (500) and the end face where the battery current output terminal of the battery casing is located is X, and the length of the battery casing is L, then 0.1≤X / L≤0.5; The length L of the battery casing is the minimum distance between the two end faces of the battery casing.

11. The battery pack as claimed in claim 10, characterized in that, 15mm≤X≤95mm; and / or, 70mm≤L≤200mm.

12. The battery pack as claimed in claim 10, characterized in that, The temperature acquisition device (500) is glued to the outer circumferential surface of the cylindrical battery (200) casing by an adhesive layer, and the thickness of the adhesive layer is b millimeters, so the range of a / b is 20~80.

13. The battery pack as claimed in claim 12, characterized in that, When the position of the temperature acquisition device (500) on the axial direction of the cylindrical battery (200) satisfies the condition: 0.3≤X / L≤0.5, the range of a / b is 20~70.

14. The battery pack as claimed in claim 10, characterized in that, The cell has a cell current output terminal, which is electrically connected to the battery current output terminal. The cell current output terminal and the battery current output terminal are located on one side of the cylindrical battery (200) in the axial direction. Then 0.2≤X / L≤0.

4.

15. The battery pack as claimed in claim 10, characterized in that, The cylindrical battery (200) has a conductive element (300) at one end where the battery current output terminal is located, and a heat exchange element (400) at the other end of the cylindrical battery (200), then 0.3≤X / L≤0.

5.

16. The battery pack according to any one of claims 1-9, characterized in that, There are at least two temperature acquisition devices (500).

17. The battery pack as claimed in claim 16, characterized in that, The angle difference between the mounting angles of the multiple temperature acquisition devices (500) is no greater than 5°.

18. A battery pack, characterized in that, It includes a frame, a cover plate, and a battery pack as described in any one of claims 1-17, wherein the frame is connected to the base plate (101) of the battery pack, and the cover plate is sealed to the frame.

19. An electrical appliance, characterized in that, Includes the battery pack as described in claim 18.

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