Battery modules, battery packs and electrical devices

Abstract

This application relates to the field of battery technology and discloses a battery module, a battery pack, and an electrical device. The battery module includes a first battery unit and a second battery unit. The first battery unit includes multiple first battery cells; the second battery unit includes multiple second battery cells, which are arranged around the periphery of the first battery unit. The first and second battery cells have different shapes. The first battery cells in this application have high energy density but poor safety performance, while the second battery cells have good safety performance but low energy density. By arranging multiple second battery cells around the periphery of the multiple first battery cells, the second battery cells protect the first battery cells, thereby improving the overall safety performance of the battery module. Furthermore, the combined use of the first and second battery cells can improve the overall energy density of the battery module.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery module, battery pack, and power-consuming device. Background Technology

[0002] Battery cells can be mainly divided into two categories according to their shape: cylindrical battery cells and prismatic battery cells. Cylindrical battery cells have the characteristics of high energy density but poor safety performance, while prismatic battery cells have the characteristics of good safety performance but low energy density.

[0003] In related technologies, cylindrical and prismatic battery cells are mostly used independently in battery modules, which limits the overall safety performance and overall energy density of the battery module. Utility Model Content

[0004] In view of this, this application provides a battery module, a battery pack, and an electrical device to solve or improve the problem that the overall safety performance and overall energy utilization of the battery module are limited when cylindrical and prismatic battery cells are used independently in the battery module.

[0005] In a first aspect, this application provides a battery module, including a first battery unit and a second battery unit. The first battery unit includes a plurality of first battery cells; the second battery unit includes a plurality of second battery cells, and the plurality of second battery cells are arranged around the periphery of the first battery unit; wherein the first battery cells and the second battery cells have different shapes.

[0006] Beneficial effects: The first battery cell has high energy density but poor safety performance, while the second battery cell has good safety performance but low energy density. By arranging multiple second battery cells around the outside of multiple first battery cells, the first battery cells are protected by the second battery cells, thereby improving the overall safety performance of the battery module. Furthermore, the combined use of the first and second battery cells can improve the overall energy density of the battery module.

[0007] In one alternative embodiment, the first battery cell is a cylindrical battery cell, and the second battery cell is a prismatic battery cell.

[0008] Beneficial effects: The first battery cell is set as a cylindrical battery cell, which has the advantages of high energy density and long driving range. The second battery cell is set as a square battery cell, which has the advantages of good safety performance. By arranging the square battery cells around the cylindrical battery cells, when the battery pack is impacted, the square batteries on the outside can protect the cylindrical battery cells on the inside, thereby improving the overall safety performance and overall energy density of the battery module.

[0009] In one alternative embodiment, multiple second battery cells are arranged along a first direction and also along a second direction, wherein the first direction intersects the second direction.

[0010] Beneficial effects: Multiple second battery cells are arranged along both the first and second directions. Through the cooperation of multiple second battery cells, a protective enclosure is formed around the first battery cell, effectively protecting the first battery cell.

[0011] In one alternative embodiment, multiple rows of the second battery cells are arranged along the first direction, and each row of the second battery cells has multiple cells arranged along the second direction.

[0012] Beneficial effect: Arranging multiple rows of second battery cells on one side of the first battery cell can increase the overall thickness of the second battery cells located on one side of the first battery cell, thereby further improving the protection effect on the first battery cell.

[0013] In one alternative embodiment, a plurality of second battery cells arranged along the first direction are parallel to a plurality of second battery cells arranged along the second direction.

[0014] Beneficial effects: The parallel arrangement of the second battery cells along different directions facilitates the layout of multiple second battery cell arrays. Furthermore, it allows for a greater number of second battery cells to be arranged within a limited space, thus increasing the overall driving range of the battery module.

[0015] In one alternative embodiment, the first battery cell includes a plurality of first battery cells arranged along a first direction, and the plurality of first battery cells arranged along the first direction are arranged in multiple rows in a second direction.

[0016] Beneficial effects: Multiple first battery cells are arranged along the first and second directions, so that the multiple first battery cells are arranged in an array, which increases the number of first battery cells in a limited space and improves the overall driving range of the battery module.

[0017] In one alternative embodiment, the diameter of the first battery cell is equal to the thickness of the second battery cell.

[0018] Beneficial effects: By making the diameter of the first battery cell equal to the thickness of the second battery cell, it is easier to arrange the first and second battery cells, thus improving space utilization.

[0019] In one alternative embodiment, the first battery unit and the second battery unit are independent power supply units.

[0020] Beneficial effects: By setting the first and second battery units to be powered independently, the different performance characteristics of the first and second battery units can be fully utilized, thus extending the lifespan of the battery module. The battery module can be adapted to different usage environments by switching between the power supply of the first and second battery units.

[0021] In one optional embodiment, the first battery cell is a lithium nickel cobalt manganese oxide battery cell, and the second battery cell is a lithium iron phosphate battery cell.

[0022] Beneficial effects: Lithium nickel cobalt manganese oxide battery cells have higher energy density, while lithium iron phosphate battery cells have higher safety and cycle life. Using the two together can not only improve the overall safety performance and lifespan of the battery module, but also improve the overall energy density of the battery module.

[0023] Secondly, this application provides a battery pack, including a housing and a battery module as described in any of the above claims, wherein the battery module is disposed within the housing.

[0024] Beneficial effects: The battery pack has the above-mentioned battery module, that is, the battery pack has a first battery unit and a second battery unit. Multiple second battery cells of the second battery unit cover the periphery of the first battery unit, and the second battery cells protect the first battery cells, thereby improving the overall safety performance of the battery pack. In addition, the first battery cells and the second battery cells work together to improve the overall energy density of the battery pack.

[0025] In one optional embodiment, the system further includes a controller and a switching mechanism, the controller being electrically connected to the switching mechanism, and the switching mechanism being electrically connected to the first battery cell and the second battery cell; wherein the controller is used to control the switching mechanism to selectively power either the first battery cell or the second battery cell.

[0026] In this embodiment, by setting up a controller and a switching mechanism to work together, the first battery unit and the second battery unit can be switched to work independently in a controllable manner, thereby adapting to different usage scenarios.

[0027] In one optional embodiment, the controller is adapted to control the switching mechanism to supply power to the first battery unit when the temperature of the battery module is lower than or equal to a first preset temperature; when the controller detects that the temperature of the battery module is higher than the first preset temperature and the remaining power of the second battery unit is higher than the first preset power, the controller controls the switching mechanism to supply power to the second battery unit.

[0028] Beneficial effects: The first battery unit has the advantages of high energy density, long driving range, and good low-temperature performance, but it has the disadvantages of poor safety performance and short lifespan. The second battery unit has the advantages of good safety performance and long lifespan, but it has the disadvantages of low energy density, short driving range, and poor low-temperature performance. By using a switching mechanism to allow the first or second battery unit to be powered independently under different usage environments, the driving range, lifespan, and low-temperature performance of the battery pack can be improved.

[0029] In one alternative implementation, the first preset temperature is -10℃ to 0℃.

[0030] Beneficial effects: When the battery module temperature is higher than the first preset temperature, it is preferable to use the second battery unit for power supply. When the battery module temperature is lower than or equal to the first preset temperature, it is preferable to use the first battery unit for power supply. By selectively using the first battery unit or the second battery unit for power supply, the overall low-temperature performance of the battery pack is improved.

[0031] Thirdly, this application provides an electrical device including the aforementioned battery pack.

[0032] Beneficial effects: The electrical device has the aforementioned battery pack, which has the advantages of long driving range, long service life and good low temperature performance. It can reduce the charging frequency and battery pack replacement frequency of the electrical device and make the electrical device suitable for low temperature environments. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram illustrating a first layout relationship between the first battery cell and the second battery cell in an embodiment of this application. Figure 2 This is a schematic diagram of a second layout relationship between the first battery cell and the second battery cell in an embodiment of this application. Figure 3 This is a schematic diagram of a third layout relationship between the first battery cell and the second battery cell in an embodiment of this application. Figure 4 This is a schematic diagram illustrating a fourth layout relationship between the first battery cell and the second battery cell in an embodiment of this application. Figure 5This is a schematic diagram of the controller and switching mechanism and the control logic of the first battery unit and the second battery unit in an embodiment of this application.

[0035] Explanation of reference numerals in the attached figures: X, first direction; Y, second direction; 1. First battery unit; 101. First battery cell; 2. Second battery unit; 201. Second battery cell; 3. Housing; 4. Controller; 5. Switching mechanism. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] The following is combined Figures 1 to 5 This describes an embodiment of the present application.

[0038] According to an embodiment of this application, in a first aspect, a battery module is provided, including a first battery unit 1 and a second battery unit 2. The first battery unit 1 includes a plurality of first battery cells 101; the second battery unit 2 includes a plurality of second battery cells 201, and the plurality of second battery cells 201 are arranged around the periphery of the first battery unit 1; wherein the first battery cells 101 and the second battery cells 201 have different shapes.

[0039] First, it should be noted that, as Figure 1 As shown, in this embodiment, both the first direction X and the second direction Y are located on a horizontal plane. The first direction X can be the left-right direction of the battery module in the figure, and the second direction Y can be the up-down direction of the battery module in the figure. The first direction X and the second direction Y intersect on the horizontal plane, and preferably, the first direction X and the second direction Y are perpendicular to each other. Of course, those skilled in the art can also adjust the specific directions referred to by the first direction X and the second direction Y according to actual needs.

[0040] Optionally, the aforementioned battery module can be used in vehicles, such as automobiles or construction machinery. Of course, the aforementioned battery module can also be used in other electrical devices, such as mobile phones, tablets, and other electronic products, or in household appliances.

[0041] Understandably, prismatic battery cells offer advantages such as good safety and long cycle life, but they also suffer from low energy density, short driving range, and poor low-temperature performance. Cylindrical batteries, on the other hand, offer advantages such as high energy density, long driving range, and good low-temperature performance, but they also have disadvantages such as poor safety and short cycle life. In related technologies, battery packs are generally composed entirely of either prismatic or cylindrical battery cells, which limits the safety performance and overall energy density of the battery pack.

[0042] In this embodiment, as Figure 1 As shown, multiple first battery cells 101 with poor safety performance and high energy density are arranged on the inner side, while multiple second battery cells 201 with good safety performance and low energy density are arranged on the outer side of the first battery cells 101. The second battery cells 201 on the outer side protect the first battery cells 101. When the battery pack is subjected to an external impact, the impact force is transmitted to the battery module inside the battery pack. The second battery cells 201 on the outer side have higher safety performance, making them less likely to be damaged by impact. At the same time, the second battery cells 201 protect the first battery cells 101 on the inner side, making them less likely to be damaged. This improves the overall safety performance of the battery module.

[0043] The first battery cell 101 has a higher energy density than the second battery cell 201. By using the first battery cell 101 and the second battery cell 201 together, the overall energy density of the battery module can be improved, thereby increasing the overall driving range of the battery module.

[0044] Furthermore, the first battery unit 1 and the second battery unit 2 can be powered independently. In the initial stage of power supply, the second battery unit 2 is used to provide power independently. When the second battery unit 2 is depleted, the first battery unit 1 is used to provide power. This fully utilizes the advantage of the long cycle life of the second battery unit 2, reduces the number of times the first battery unit 1 is used, and improves the lifespan of the first battery unit 1, thereby improving the overall lifespan of the battery module.

[0045] Optionally, the first battery cell 101 can be cylindrical or elliptical, and the second battery cell 201 can be square or polygonal. Alternatively, the first battery cell 101 can be a power supply structure with high energy density but poor safety performance, while the second battery cell 201 can be a power supply structure with low energy density but good safety performance.

[0046] Of course, in some cases, the second battery cell 201 may have advantages such as good safety performance and high energy density, but disadvantages such as high manufacturing and usage costs, while the first battery cell 101 may have the characteristics of low manufacturing cost but poor safety performance. In this case, the first battery cell 101 and the second battery cell 201 can still be used in combination to meet different usage requirements.

[0047] Optionally, such as Figure 1 As shown, any two adjacent second battery cells 201 are spaced apart, so that there is a gap between the two adjacent second battery cells 201, which facilitates heat dissipation of the second battery cells 201.

[0048] In one embodiment, the first battery cell 101 is a cylindrical battery cell, and the second battery cell 201 is a square battery cell.

[0049] In this embodiment, as Figure 1 As shown, the first battery cell 101 is a cylindrical battery cell, which has the advantages of high energy density and long driving range. The second battery cell 201 is a square battery cell, which has the advantage of good safety performance. By arranging the square battery cells around the cylindrical battery cells, when the battery pack is impacted, the square batteries on the outside can protect the cylindrical battery cells on the inside, thereby improving the overall safety performance and overall energy density of the battery module.

[0050] Furthermore, the second battery cell 201 adopts a square battery cell, which has a relatively regular outer contour. Therefore, multiple second battery cells 201 can be arranged at intervals along a preset direction, so that when multiple second battery cells 201 surround the periphery of the first battery cell 1, they can form a relatively regular frame structure, which facilitates the overall layout of the battery module.

[0051] In one embodiment, multiple second battery cells 201 are arranged along a first direction X and multiple second directions Y, with the first direction X intersecting the second direction Y.

[0052] In this embodiment, as Figure 1 As shown, the second battery cell 201 can be arranged along the first direction X or the second direction Y, thereby forming a protective enclosure around the first battery cell 1 through the cooperation of multiple second battery cells 201, effectively protecting the first battery cell 1. At the same time, multiple second battery cells 201 can also form a frame structure with multiple rows and columns in different directions, which facilitates the layout of multiple second battery cells 201.

[0053] Optionally, the first direction X intersects the second direction Y. When the first direction X and the second direction Y are not perpendicular to each other, the frame structure formed by the multiple second battery cells 201 is a parallelogram structure. When the first direction X and the second direction Y are perpendicular to each other, the frame structure formed by the multiple second battery cells 201 is a rectangular structure. Based on the above, it is preferable to adopt the arrangement where the first direction X and the second direction Y are perpendicular to each other, which can keep the overall outer contour of the battery module relatively regular.

[0054] Of course, in addition to the above-mentioned arrangement of multiple second battery cells 201 along the first direction X and multiple second battery cells 201 along the second direction Y, the specific arrangement of the multiple second battery cells 201 can also be adapted to actual needs. For example, the multiple second battery cells 201 can also be arranged in a circular or polygonal manner around the first battery unit 1. In this way, the battery module can be adapted to different battery pack layouts.

[0055] In one embodiment, multiple rows of second battery cells 201 are arranged along a first direction X, and multiple second battery cells 201 are arranged along a second direction Y.

[0056] In this embodiment, multiple rows of second battery cells 201 are arranged sequentially at intervals along the first direction X. The specific number of each row of second battery cells 201 along the second direction Y can be adaptively adjusted so that the middle area of ​​the multiple second battery cells 201 arranged in an array forms a receiving space, and the first battery cell 1 is arranged in the receiving space.

[0057] In one specific implementation, such as Figure 1 As shown, six rows of second battery cells 201 are arranged along the first direction X. Among the two rows of second battery cells 201 located on both sides along the first direction X, a larger number of second battery cells 201 are arranged along the second direction Y. The remaining four rows of second battery cells 201 located in the middle area have a smaller number of second battery cells 201 arranged along the second direction. Thus, the two rows of second battery cells 201 located on both sides and the four rows of second battery cells 201 located in the middle area cooperate to define a space that can accommodate the first battery unit 1.

[0058] In another specific implementation, such as Figure 2As shown, six rows of second battery cells 201 are arranged along the first direction X. Of the four rows of second battery cells 201 located on either side of the first battery cell 1 along the first direction X, a larger number of second battery cells 201 are arranged along the second direction Y. The remaining two rows of second battery cells 201 located in the middle region have a smaller number of second battery cells 201 arranged along the second direction Y. This arrangement also defines the space that can accommodate the first battery unit 1. Furthermore, this configuration, with multiple rows of second battery cells 201 arranged on one side of the first battery unit 1, increases the overall width of these multiple rows of second battery cells 201 along the first direction X, thereby further enhancing the protective effect on the first battery unit 1.

[0059] Of course, in addition to the layout described above, the specific layout of the second battery cell 201 can also be adapted to meet actual needs.

[0060] Optionally, the energy storage capacity of the second battery unit 2 can be configured to be in the range of 10% to 90% of the total energy storage capacity of the battery module.

[0061] Optionally, such as Figure 1 , Figure 2 As shown, the multiple second battery cells 201 in each column can be arranged in an aligned manner or in an interleaved manner to meet different usage requirements.

[0062] In one embodiment, a plurality of second battery cells 201 arranged along a first direction X are parallel to a plurality of second battery cells 201 arranged along a second direction Y.

[0063] In this embodiment, the second battery cells 201 arranged in different directions are parallel to each other, which facilitates the array arrangement of multiple second battery cells 201. Furthermore, it increases the number of second battery cells 201 within a limited space, thereby improving the overall driving range of the battery module.

[0064] For example, such as Figure 1 , Figure 2 As shown, the second battery cell 201 has a length direction and a thickness direction. The length direction of the plurality of second battery cells 201 is parallel to the first direction X, and the thickness direction of the plurality of second battery cells 201 is parallel to the second direction Y.

[0065] Of course, in addition to the settings mentioned above, such as Figure 3 , Figure 4As shown, the length direction of the plurality of second battery cells 201 is parallel to the second direction Y, and the thickness direction of the plurality of second battery cells 201 is parallel to the first direction X. In this arrangement, in some cases, due to the length dimension of the second battery cells 201, there may be a large gap between two adjacent second battery cells 201 along the second direction Y. This gap cannot accommodate further second battery cells 201, easily resulting in wasted space. Therefore, a first battery cell 101 can be arranged within this gap, and preferably, the first battery cell 101 does not protrude beyond the outer edge of the outermost second battery cell 201, ensuring that the second battery cell 201 protects the first battery cell 101.

[0066] In one embodiment, the first battery cell 1 includes a plurality of first battery cells 101 arranged along a first direction X, and the plurality of first battery cells 101 arranged along the first direction X are arranged in multiple rows along a second direction Y.

[0067] In this embodiment, as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, multiple first battery cells 101 are arranged along the first direction X and the second direction Y, so that the multiple first battery cells 101 are also arranged in an array, thereby increasing the number of first battery cells 101 within a limited space and improving the overall driving range of the battery module.

[0068] Optionally, such as Figure 1 As shown, in the plurality of first battery cells 101 arranged along the first direction X, two adjacent first battery cells 101 can be fitted together, and in the plurality of rows of first battery cells 101 arranged along the second direction Y, two adjacent rows of first battery cells 101 can be spaced apart. In this way, not only can the plurality of first battery cells 101 be made compact, but the heat dissipation effect of the first battery cells 101 can also be maintained.

[0069] Optionally, the first battery cells 101 arranged in columns along the second direction Y can be aligned or staggered to meet different usage requirements.

[0070] In one embodiment, the diameter of the first battery cell 101 is equal to the thickness of the second battery cell 201.

[0071] In this embodiment, as Figure 1 As shown, the first battery cell 101 is a cylindrical battery cell, and the second battery cell 201 is a square battery cell. The square battery cell has two opposing large surfaces and a sidewall connecting the large surfaces, wherein the distance between the two large surfaces is the thickness of the square battery cell.

[0072] Assuming that the length direction of the second battery cell 201 is parallel to the first direction X, and the thickness direction of the second battery cell 201 is parallel to the second direction Y, when multiple second battery cells 201 are arranged along the second direction Y, the first battery cell 101 and the second battery cell 201 can correspond to each other in the first direction X, thereby facilitating the layout of the first battery cell 101 and the second battery cell 201, and further utilizing the second battery cell 201 to protect the first battery cell 101.

[0073] In one embodiment, the first battery unit 1 and the second battery unit 2 are independent power supply units.

[0074] In this embodiment, the first battery unit 1 and the second battery unit 2 are electrically isolated from each other and are not directly connected in series or parallel. The first battery unit 1 and the second battery unit 2 each have independent current paths and can independently provide power to the outside. Thus, by setting the first battery unit 1 and the second battery unit 2 to be powered independently, the different performance characteristics of the first battery unit 1 and the second battery unit 2 can be fully utilized, thereby improving the lifespan of the battery module. The battery module can be adapted to different usage environments by switching the power supply between the first battery unit 1 and the second battery unit 2.

[0075] In one embodiment, the first battery cell 101 is a lithium nickel cobalt manganese oxide battery cell, and the second battery cell 201 is a lithium iron phosphate battery cell.

[0076] In this embodiment, the lithium nickel cobalt manganese oxide battery cell has a higher energy density, and the lithium iron phosphate battery cell has higher safety and cycle life. Using them together not only improves the overall safety performance and lifespan of the battery module, but also increases its overall energy density. Of course, the first battery cell 101 and the second battery cell 201 can also be made of other materials besides those mentioned above.

[0077] Secondly, this application provides a battery pack, including a housing 3 and a battery module as described above, wherein the battery module is disposed within the housing 3.

[0078] In this embodiment, as Figure 1 As shown, the battery pack has the aforementioned battery module, which is housed within the casing 3. The battery pack includes a first battery unit 1 and a second battery unit 2. Multiple second battery cells 201 of the second battery unit 2 surround the first battery unit 1, protecting the first battery cell 101 and thus improving the overall safety performance of the battery pack. Furthermore, the combined use of the first battery cell 101 and the second battery cell 201 enhances the overall energy density of the battery pack.

[0079] In one embodiment, the system further includes a controller 4 and a switching mechanism 5, wherein the controller 4 is electrically connected to the switching mechanism 5, and the switching mechanism 5 is electrically connected to the first battery unit 1 and the second battery unit 2; wherein the controller 4 is used to control the switching mechanism 5 to selectively supply power to the first battery unit 1 or the second battery unit 2.

[0080] In this embodiment, as Figure 5 As shown, by setting the controller 4 and the switching mechanism 5 in cooperation, the first battery unit 1 and the second battery unit 2 can be controlled to switch to independent operation, thereby adapting to different usage scenarios. At the same time, the controllable switching of the first battery unit 1 and the second battery unit 2 to operate independently also allows the battery pack to operate in different modes, making full use of the advantages of the first battery unit 1 and the second battery unit 2, and improving the battery pack's range, service life and low-temperature performance.

[0081] In one embodiment, the controller 4 is adapted to control the switching mechanism 5 to supply power to the first battery unit 1 when the temperature of the battery module is lower than or equal to the first preset temperature; when the controller 4 detects that the temperature of the battery module is higher than the first preset temperature and the remaining power of the second battery unit 2 is higher than the first preset power, the controller 4 controls the switching mechanism 5 to supply power to the second battery unit 2.

[0082] In this embodiment, the first battery unit 1 has the advantages of high energy density, long driving range, and good low-temperature performance, but it has the disadvantages of poor safety performance and short service life. The second battery unit 2, on the other hand, has the advantages of good safety performance and long service life, but it has the disadvantages of low energy density, short driving range, and poor low-temperature performance. Therefore, the switching mechanism 5 can be used to independently power either the first battery unit 1 or the second battery unit 2 under different usage environments to meet different usage needs.

[0083] In one specific implementation, when the ambient temperature is high, the controller 4 detects that the temperature of the battery module is higher than the first preset temperature, and at this time the remaining power of the second battery unit 2 is higher than the first preset power. The controller 4 controls the switching mechanism 5 to make the second battery unit 2 supply power alone. After the second battery unit 2 has consumed all its power, the first battery unit 1 is activated through the switching mechanism 5, and the battery pack is powered by taking advantage of the high energy density of the first battery unit 1.

[0084] With this configuration, the second battery cell 201 used in the second battery unit 2 has the advantage of a long cycle life. When the driving range is short and the charging frequency is high, only the second battery cell 2 needs to be charged. That is, the second battery cell 2 in the battery pack is charged and discharged, while the first battery cell 1 in the battery pack does not participate in the charging and discharging operation. This can improve the cycle life of the first battery cell 1. Moreover, when the second battery cell 2 is depleted, it can still be powered by the first battery cell 1, thereby improving the range of the battery pack.

[0085] In another specific implementation, when the ambient temperature is low, the controller 4 detects that the temperature of the battery module is lower than or equal to the first preset temperature. The controller 4 controls the switching mechanism 5 to supply power to the first battery unit 1 alone. After the battery module heats up, the controller 4 detects that the temperature of the battery module is higher than the first preset temperature. At this time, when the remaining power of the second battery unit 2 is higher than the first preset power, the controller 4 controls the switching mechanism 5 to supply power to the second battery unit 2 alone. After the second battery unit 2 has consumed all its power, the first battery unit 1 is activated again through the switching mechanism 5, and the battery pack is powered by taking advantage of the high energy density of the first battery unit 1.

[0086] With this configuration, the first battery cell 101 used in the first battery unit 1 has the advantage of good low-temperature performance. In low-temperature environments, the first battery cell 1 can be powered independently, ensuring that it can still effectively output power even in cold conditions, preventing the electrical device from failing to start and ensuring the reliability of the battery pack. Furthermore, after the battery pack generates heat during operation and the battery module heats up to a temperature higher than the first preset temperature, switching to the second battery cell 2 for independent power supply can also improve the cycle life of the first battery cell 1.

[0087] In one embodiment, the first preset temperature is -10℃ to 0℃. When the battery module temperature is higher than the first preset temperature, it is preferable to use the second battery unit 2 for power supply. When the battery module temperature is lower than or equal to the first preset temperature, it is preferable to use the first battery unit 1 for power supply. By selectively using the first battery unit 1 or the second battery unit 2 for power supply, the overall low-temperature performance of the battery pack is improved.

[0088] Of course, the specific range and value of the first preset temperature can be adjusted adaptively according to the actual situation.

[0089] In one embodiment, the first preset power level can be set to 5% to 25% of the total power storage capacity of the second battery unit 2, or it can be set to completely deplete the power of the second battery unit 2.

[0090] Thirdly, this application provides an electrical device including the aforementioned battery pack.

[0091] In this embodiment, the power device has the aforementioned battery pack, which has the advantages of long driving range, long service life and good low-temperature performance. It can reduce the charging frequency and replacement frequency of the battery pack in the power device, and make the power device suitable for low-temperature environments.

[0092] Alternatively, the electrical device can be a vehicle, such as a car or construction machinery, or an electronic product such as a mobile phone or tablet, or a household appliance.

[0093] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery module, characterized in that, include: The first battery unit (1) includes a plurality of first battery cells (101). The second battery unit (2) includes a plurality of second battery cells (201), and the plurality of second battery cells (201) are arranged around the periphery of the first battery unit (1); The first battery cell (101) and the second battery cell (201) have different shapes.

2. The battery module according to claim 1, characterized in that, The first battery cell (101) is a cylindrical battery cell, and the second battery cell (201) is a square battery cell.

3. The battery module according to claim 1, characterized in that, Multiple second battery cells (201) are arranged along a first direction (X) and multiple second directions (Y), and the first direction (X) and the second direction (Y) intersect.

4. The battery module according to claim 3, characterized in that, Multiple rows of second battery cells (201) are arranged along the first direction (X), and each row of second battery cells (201) has multiple cells arranged along the second direction (Y).

5. The battery module according to claim 3, characterized in that, The plurality of second battery cells (201) arranged along the first direction (X) are parallel to each other as are the plurality of second battery cells (201) arranged along the second direction (Y).

6. The battery module according to claim 1, characterized in that, The first battery cell (1) includes a plurality of first battery cells (101) arranged along a first direction (X), and the plurality of first battery cells (101) arranged along the first direction (X) are arranged in multiple rows in a second direction (Y).

7. The battery module according to any one of claims 2-6, characterized in that, The diameter of the first battery cell (101) is equal to the thickness of the second battery cell (201).

8. The battery module according to any one of claims 2-6, characterized in that, The first battery unit (1) and the second battery unit (2) are independent power supply units.

9. The battery module according to any one of claims 2-6, characterized in that, The first battery cell (101) is a lithium nickel cobalt manganese oxide battery cell, and the second battery cell (201) is a lithium iron phosphate battery cell.

10. A battery pack, characterized in that, include: Box (3); The battery module according to any one of claims 1-9, wherein the battery module is disposed within the housing (3).

11. The battery pack according to claim 10, characterized in that, Also includes: A controller (4) and a switching mechanism (5), wherein the controller (4) is electrically connected to the switching mechanism (5), and the switching mechanism (5) is electrically connected to the first battery unit (1) and the second battery unit (2); The controller (4) is used to control the switching mechanism (5) to selectively power the first battery unit (1) or the second battery unit (2).

12. The battery pack according to claim 11, characterized in that, The controller (4) is adapted to control the switching mechanism (5) to supply power to the first battery unit (1) when the temperature of the battery module is lower than or equal to the first preset temperature. When the controller (4) detects that the temperature of the battery module is higher than the first preset temperature and the remaining power of the second battery unit (2) is higher than the first preset power, the controller (4) controls the switching mechanism (5) to supply power to the second battery unit (2).

13. The battery pack according to claim 12, characterized in that, The first preset temperature is -10℃ to 0℃.

14. An electrical appliance, characterized in that, The battery pack includes any one of claims 10-13.

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