Battery pack

Abstract

The invention discloses a battery pack which comprises a shell and at least one battery cell assembly contained in the shell, the battery cell assembly comprises a support and a plurality of battery cells electrically connected with one another, the support is used for fixing the battery cells, and the support is used for fixing the battery cells. The plurality of battery cells are arranged in parallel in the axial direction and are arranged in an array in a first direction and a second direction which are vertical to the axial direction of the battery cells, the plurality of battery cells are arranged into a plurality of rows of battery cell groups, each row of battery cell group extends along the first direction, and the plurality of rows of battery cell groups are arranged at intervals in the second direction; in the first direction, the distance between two adjacent battery cells in at least one column is reduced from the middle to the two ends, and / or in the second direction, the distance between two adjacent columns of battery cell groups is reduced from the middle to the two ends. The battery pack can solve the problem of large temperature difference between the battery cells in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of electric tools, and in particular to a battery pack. Background Art

[0002] A battery pack is generally a battery module composed of multiple battery cells connected in series or in parallel. Furthermore, multiple battery modules can also be connected in series or in parallel to form a battery cell group with a certain voltage and capacity. Summary of the Invention

[0003] The present invention provides a battery pack, comprising a shell and at least one battery cell assembly accommodated in the shell, wherein the battery cell assembly comprises a bracket and a plurality of battery cells electrically connected to each other, the bracket being used to fix the battery cells, further, the axes of the plurality of battery cells are arranged in parallel and arranged in an array in a first direction and a second direction perpendicular to the axes of the battery cells, wherein the plurality of battery cells are arranged into a plurality of columns of battery cell groups, each column of the battery cell groups extending along the first direction, and the plurality of columns of the battery cell groups are spaced apart in the second direction; in the first direction, the distance between two adjacent battery cells in at least one column decreases from the middle to both ends, and / or, in the second direction, the distance between two adjacent columns of the battery cell groups decreases from the middle to both ends.

[0004] In some embodiments, the number of battery cells in at least one column of the battery cell group is N, N is an odd number, N is greater than or equal to 5, and in the first direction, the distance between two battery cells symmetrically distributed around the middle battery cell in the same column and their adjacent battery cells is equal.

[0005] In some embodiments, the number of battery cells in at least one column of the battery cell group is N, N is an even number, N is greater than or equal to 4, the number of intermediate battery cells in the same column is N1, N1 is an even number, N1 is greater than or equal to 2, and in the first direction, the distance between adjacent intermediate battery cells in the same column is greater than the distance between other adjacent battery cells.

[0006] In some embodiments, the number of battery cells in at least one column of the battery cell group is N, N is an even number, N is greater than or equal to 6, the number of intermediate battery cells in the same column is N1, N1 is an even number, N1 is greater than or equal to 4, and in the first direction, the distance between adjacent intermediate battery cells in the same column is equal.

[0007] In some embodiments, in the first direction, two battery cells symmetrically distributed around the middle battery cell in the same column are equidistant from their respective adjacent battery cells.

[0008] In some embodiments, the number of columns of the battery cell groups is M, M is an odd number, M is greater than or equal to 5, and in the second direction, the distances between two columns of battery cell groups symmetrically distributed around the middle column of battery cell groups and the battery cell groups in their respective adjacent columns are equal.

[0009] In some embodiments, the number of columns of the battery cell groups is M, M is an even number, M is greater than or equal to 4, the number of middle column battery cell groups is M1, M1 is an even number, M1 is greater than or equal to 2, and in the second direction, the distance between adjacent middle column battery cell groups is greater than the distance between other adjacent column battery cell groups.

[0010] In some embodiments, the number of columns of the battery cell groups is M, M is an even number, M is greater than or equal to 6, the number of battery cell groups in the middle columns is M1, M1 is an even number, M1 is greater than or equal to 4, and in the second direction, the distances between adjacent battery cell groups in the middle columns are equal.

[0011] In some embodiments, in the second direction, the distances between two columns of battery cell groups symmetrically distributed around the middle column of battery cell groups and the battery cell groups in their respective adjacent columns are equal.

[0012] In some embodiments, the distance between the center of any of the battery cells and the center of an adjacent battery cell in the same column is not equal to the distance between the centers of adjacent battery cells in the adjacent column.

[0013] In some embodiments, the battery cells in two adjacent columns of the battery cell groups are arranged in a staggered manner.

[0014] In some embodiments, the battery pack includes at least two battery cell assemblies, at least two of the battery cell assemblies are spaced apart along the second direction, and the distance between two adjacent columns of battery cell groups in adjacent battery cell assemblies is L, wherein L is greater than the distance between two adjacent columns of battery cell groups in each of the adjacent battery cell assemblies.

[0015] In some embodiments, the bracket is made of a thermally conductive material, and the thermal conductivity of the bracket is greater than 1 W / mK.

[0016] In some embodiments, the bracket includes a first bracket and a second bracket arranged opposite to each other, and the first bracket and the second bracket enclose a plurality of first mounting parts and second mounting parts for fixing the battery cell, wherein the first mounting part fully wraps the circumference of the battery cell, and the second mounting part partially wraps the circumference of the battery cell.

[0017] In some embodiments, in the first direction and / or the second direction, the first mounting portion wraps the battery cell located in the middle, and the second mounting portion wraps the battery cells located at both ends.

[0018] In some embodiments, in the first direction and / or the second direction, the surface area of the circumference of the battery core wrapped by the second mounting portion decreases from the middle to both ends.

[0019] In some embodiments, the second mounting portion wraps a portion of the circumference of the battery cell at both axial ends.

[0020] The beneficial effect of the present invention is that it ensures that the temperature difference of each battery cell during charging and discharging is controlled within a small range, thereby improving the performance and life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The embodiments of the present application will be further described with reference to the following drawings:

[0022] Figure 1 is a schematic diagram of the three-dimensional structure of a battery pack according to an embodiment of the present invention;

[0023] Figure 2 is a schematic diagram of the inner cavity of a battery pack according to an embodiment of the present invention;

[0024] Figure 3 is an exploded view of a battery pack according to an embodiment of the present invention;

[0025] Figure 4 1 is a schematic diagram of the three-dimensional structure of the outer shell body and the inner shell body of a battery pack according to an embodiment of the present invention;

[0026] Figure 5 1 is a schematic diagram of the three-dimensional structure of a cell assembly of a battery pack according to an embodiment of the present invention;

[0027] Figure 6A 1 is a schematic structural diagram of a terminal block, a terminal board, and connecting wires of a battery pack according to an embodiment of the present invention;

[0028] Figure 6B 1 is another schematic diagram of the three-dimensional structure of the outer shell body and the inner shell body of the battery pack according to one embodiment of the present invention;

[0029] Figure 7 yes Figure 6A and Figure 6B Schematic diagram of the cross-sectional structure after assembly;

[0030] Figure 8 is an exploded view of an inner shell cover of a battery pack according to an embodiment of the present invention;

[0031] Figure 9 is a cross-sectional view of an inner shell cover of a battery pack according to an embodiment of the present invention;

[0032] Figure 10 This is a cross-sectional view of a battery pack according to one embodiment of the present invention when the inner shell cover and the cell assembly are installed in the outer shell body and the inner shell body;

[0033] Figure 10A is a cross-sectional view of a housing cover according to an embodiment of the present invention;

[0034] Figure 10B It is along Figure 10A A1-A1 line cross-sectional view;

[0035] Figure 10C It is along Figure 10A A2-A2 line cross-sectional view;

[0036] Figure 10D It is along Figure 10A B1-B1 line cross-sectional view;

[0037] Figure 10E It is along Figure 10A Cross-sectional view along the B2-B2 line;

[0038] Figure 11 is an exploded view of a cell assembly of a battery pack according to an embodiment of the present invention;

[0039] Figure 12 yes Figure 11 Schematic diagram from another perspective;

[0040] Figure 13 Schematic diagram of the arrangement of brackets within a cell assembly in a battery pack according to an embodiment of the present invention;

[0041] Figure 14 yes Figure 13 Enlarged schematic diagram of area I;

[0042] Figure 15 yes Figure 13 Enlarged schematic diagram of the middle II region;

[0043] Figure 16 Schematic diagram of the arrangement of a row of battery cell groups according to one embodiment of the present invention;

[0044] Figure 17 is a schematic diagram of the arrangement of a row of battery cell groups according to another embodiment of the present invention;

[0045] Figure 18 Schematic diagram of the arrangement of multiple rows of battery cell groups according to one embodiment of the present invention;

[0046] Figure 19 is a schematic diagram of the arrangement of multiple rows of battery cell groups according to another embodiment of the present invention;

[0047] Figure 20 FIG. 1 is a schematic diagram of the arrangement of battery cells in a battery cell assembly in a battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present application will be described in detail below with reference to the various embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional modifications made by a person skilled in the art based on these embodiments are included within the scope of protection of the present application.

[0049] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be an intermediate element. In the illustrated embodiments, the direction representations, i.e., up, down, left, right, front, and back, etc., are relative and are used to explain that the structure and movement of the different components in this application are relative. These representations are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, it is considered that these representations will also change accordingly.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] Some embodiments of the present invention provide a battery pack that can be detachably connected to an external device.

[0052] The external device can be an electrical device or a charger. When the battery pack is connected to the electrical device, the battery pack can provide electrical energy to the electrical device. Optionally, the electrical device can be a power tool, a household appliance, etc. The power tool can be a handheld power tool, such as an electric hammer, an electric drill, an angle grinder, etc., or a garden power tool, such as a hair dryer, a chain saw, an intelligent lawn mower, etc. The battery pack can be connected to the garden power tool by connecting to a carrying device. The carrying device may include a shoulder strap and / or a waist belt, etc. When the battery pack is connected to the charger, the charger connected to the power source can provide electrical energy to the battery pack. Figure 1 is a schematic diagram of the three-dimensional structure of a battery pack according to an embodiment of the present invention. Figure 2 is a schematic diagram of the inner cavity of a battery pack according to an embodiment of the present invention. Figure 3 is an exploded view of a battery pack according to an embodiment of the present invention. Figure 4 1 is a schematic diagram of the three-dimensional structure of the outer shell body and the inner shell body of the battery pack according to one embodiment of the present invention. Figure 5 1 is a schematic diagram of the three-dimensional structure of a cell assembly of a battery pack according to an embodiment of the present invention. Figure 6A 1 is a schematic structural diagram of a terminal block, a terminal board, and connecting wires of a battery pack according to an embodiment of the present invention. Figure 6B 1 is another three-dimensional structural diagram of the outer shell body and the inner shell body of the battery pack according to one embodiment of the present invention. Figure 7 yes Figure 6A and Figure 6B Schematic diagram of the combined cross-sectional structure.

[0053] Please also refer to Figures 1 to 7 The battery pack 100 includes a shell 1 and at least one battery cell assembly 2 accommodated in the shell 1.

[0054] In real-world work scenarios, users often need to use the battery pack even on rainy days. Furthermore, when working in the garden, there is often dew or water vapor on the grass, which places high demands on the battery pack's waterproofness.

[0055] In some embodiments, in order to meet the high waterproof requirements of the battery pack, no ventilation holes are provided on the shell 1 of the battery pack 100 to prevent water vapor from entering the interior of the shell, thereby better protecting the battery cell assembly 2.

[0056] In some embodiments, the battery cell assembly 2 is housed in a double-layer shell to achieve a better waterproof effect. Specifically, the shell 1 includes an outer shell and an inner shell, the inner shell is used to house the battery cell assembly 2, and the outer shell is used to house the inner shell.

[0057] Furthermore, the outer shell includes an outer shell body 11 and an outer shell cover 12, and the inner shell includes an inner shell body 14 and an inner shell cover 13. The outer shell body includes an outer shell opening (not shown), and the outer shell cover 12 covers the outer shell opening. The inner shell body 14 includes an inner shell opening (not shown), and the inner shell cover 13 covers the inner shell opening.

[0058] Optionally, the inner shell body 14 and the outer shell body 11 are integrally formed, and the outer shell cover 12 and the inner shell cover 13 are separately provided. It should be noted that the housing can also be constructed in other configurations, such as the outer shell cover and the inner shell cover are integrally formed, or the inner shell body and the outer shell body are separately provided, etc., and the present invention is not limited thereto.

[0059] In some embodiments, the battery cell assembly 2 is housed in the inner shell body 14 , the inner shell cover 13 covers the inner shell body 14 , and the outer shell cover 12 covers the outer shell body 11 .

[0060] In some embodiments, when installing the battery pack, the battery cell assembly 2 is first placed into the outer shell body 11 , then the inner shell cover 13 is put on, and finally the outer shell cover 12 is put on.

[0061] In some embodiments, a sealing ring (not shown) is provided between the circumferential outer edge of the inner shell body 14 and the circumferential outer edge of the corresponding inner shell cover 13 to achieve waterproofing. Figure 10A and Figure 10D As shown, a full circle of sealing member 124 (sealing strip or silicone ring or foam) is installed inside the outer peripheral groove of the inner shell cover 13. The sealing member 124 has an interference fit with the ribs of the outer shell body 11 to ensure waterproofness.

[0062] like Figure 1As shown, the battery pack 100 includes a pair of slide rails 117 provided on the housing body 11 , and the pair of slide rails 117 are matched with corresponding slide grooves provided on the external device to enable the battery pack 100 to slide and mate with the external device.

[0063] The battery pack 100 also includes a terminal assembly, which includes at least one terminal 112. Terminal 112 is configured to plug into a corresponding terminal on an external device to achieve an electrical connection between the battery pack and the external device. The housing body 11 is provided with a terminal slot 111, which at least partially accommodates at least one terminal 112. Optionally, a terminal slot 113 is provided between a pair of slide rails 117.

[0064] The terminal assembly also includes a terminal base 113 for fixedly supporting at least one terminal 112. Terminal base 113 is at least partially disposed within terminal slot 111. The terminal assembly also includes a terminal plate 114 connected to terminal base 113, with terminals 112 welded to terminal plate 114. The terminal assembly also includes multiple connecting wires 115, with each terminal 112 and terminal plate 114 connected to at least one connecting wire 115 to enable power and / or information transmission.

[0065] like Figure 6A 、 Figure 6B and Figure 7 As shown, since the terminal slot 111 is exposed, water vapor can enter through it, thereby affecting the terminals accommodated in the terminal slot 111, causing the terminals to have a short-circuit risk. In some embodiments, a seal is provided between the housing body 11 and the terminal seat 113 to achieve waterproofing. Optionally, the seal is configured as a sealing ring 1131, and the housing body 11 is provided with a waterproof rib 1111 that cooperates with the sealing ring 1131. When the terminal seat 113 is installed on the housing body 11, the waterproof rib 111 presses the electrode seat sealing ring 1131 so that the terminal seat 113 and the housing body 11 are interference fit to ensure sealing and achieve the purpose of waterproofing. Optionally, the sealing ring 1131 and the terminal seat 113 are integrally formed.

[0066] like Figure 1 As shown, the battery pack 100 further includes a locking slot 116 provided on the housing body 11 , the locking slot 116 being configured to engage with a corresponding locking member of an external device to achieve connection and locking of the battery pack 100 with the external device. Optionally, the locking slot 116 is provided above the terminal slot 111 .

[0067] like Figure 4As shown, the battery pack 100 also includes a first retaining structure for retaining the battery cell assembly 2. The first retaining structure includes a retaining member 118 disposed on the housing body 11 and a rectangular column 213 disposed on the battery cell assembly 2. The retaining member 118 cooperates with the rectangular column 213 to retain the battery cell assembly 2. Optionally, the retaining member 118 is provided as a plurality of vertically arranged reinforcing ribs on the inner side of the housing body 11.

[0068] like Figure 4 and Figure 5 As shown, the battery pack 100 also includes a second retaining structure for retaining the battery cell assembly 2. The second retaining structure includes a positioning post 119 provided on the housing body 11 and a positioning hole 212 provided on the battery cell assembly 2. The positioning post 119 engages with the positioning hole 212 to retain the battery cell assembly 2. Optionally, the positioning post 119 is located inside the housing body 11 and below the terminal slot 111.

[0069] Please refer to Figure 4 and Figure 5 , the battery pack 100 also includes a first fixing structure for fixing the shell body 11 and the shell cover 12. The first fixing structure includes a first mounting column 140 provided on the shell body 11, a first mounting hole (not shown) provided on the shell cover 12, and a first connecting member (not shown) connecting the first mounting column 140 and the first mounting hole. The first connecting member passes through the first mounting hole and is connected to the first mounting column 140 to fasten the shell body 11 to the shell cover 12. Optionally, the first mounting column 140, the first mounting hole, and the first connecting member each include a plurality, the first mounting column 140 is configured as a screw column, and the first connecting member is configured as a screw. Optionally, the plurality of first mounting columns 140 are evenly distributed on the circumferential outer ring inside the shell body 11, and the plurality of first mounting holes are evenly distributed on the corresponding circumferential outer ring of the shell cover 12.

[0070] Please refer to Figure 3 and Figure 4 , the battery pack 100 also includes a second fixing structure for fixing the outer shell body 11 and the inner shell cover 13. The second fixing structure includes a second mounting column 141 provided on the outer shell body 11, a second mounting hole 130 provided on the inner shell cover 13, and a second connecting member (not shown) connecting the second mounting column 141 and the second mounting hole 130. The second connecting member passes through the second mounting hole 130 and is connected to the second mounting column 141 to fasten the outer shell body 11 to the inner shell cover 13. Optionally, the second mounting column 141, the second mounting hole 130, and the first connecting member each include a plurality, the second mounting column 141 is configured as a screw column, and the second connecting member is configured as a screw. Optionally, the plurality of second mounting columns 141 are evenly distributed on the circumferential outer ring inside the outer shell body 11, and the plurality of second mounting holes 130 are evenly distributed on the corresponding circumferential outer ring of the inner shell cover 13.

[0071] Please refer to Figure 4 and Figure 5 The battery pack 100 further includes a third fixing structure for fixing the housing body 11 and the battery cell assembly 2. The third fixing structure includes a third mounting post 142 provided on the housing body 11, a third mounting hole 211 provided on the battery cell assembly 2, and a third connecting member (not shown) connecting the third mounting post 142 and the third mounting hole 211. Figure 10B As shown, the third connecting member 121 passes through the third mounting hole and is connected to the third mounting column 142 to fasten the battery cell assembly 2 to the shell body 11. Optionally, the third mounting column 142, the third mounting hole 211, and the third connecting member each include a plurality of them, the third mounting column 142 is configured as a screw column, and the third connecting member 121 is configured as a long screw. The battery cell assembly 2 is pressed against the shell body 11 by the long screw 121 to ensure that the battery cell assembly 2 does not move in the Z-axis direction. Optionally, the plurality of third mounting columns 142 are evenly distributed on the circumferential outer ring inside the shell body 11, and the plurality of third mounting holes 211 are evenly distributed on the corresponding circumferential outer ring of the battery cell assembly 2.

[0072] Figure 8 FIG. 1 is an exploded view of the inner shell cover 13 of the battery pack 100 according to an embodiment of the present invention. Figure 9 FIG. 1 is a cross-sectional view of the inner housing cover 13 of the battery pack 100 according to an embodiment of the present invention.

[0073] like Figure 8 and Figure 9 As shown, the battery pack 100 further includes a status display component for displaying the status of the battery pack 100 .

[0074] The status display assembly includes a status display circuit board 131 , a light guide column 132 , a light isolation plate 133 , an indicator light column 1311 and a button provided on the status display circuit board 131 .

[0075] The indicator light column 1311 includes multiple indicators, including a battery indicator light, a Bluetooth indicator light, and an abnormality indicator light. When the button is triggered, the number of indicator lights that illuminate indicates the battery pack charge level. The Bluetooth indicator light illuminates when the battery pack 100 receives a Bluetooth signal. The abnormality indicator light illuminates when the battery pack 100 experiences an abnormality. Optionally, the indicator light column 1311 is an LED light column.

[0076] Light guide 132 is used to guide the light emitted by indicator light column 1311 to the outside of the housing for easy viewing by the user. To achieve a waterproof effect, light guide 132 is configured as an elastic member that can provide a sealing and waterproof effect. Optionally, light guide 132 is configured as a silicone material. Waterproof light guide 132 and inner housing cover 13 are interference fit to meet waterproof requirements.

[0077] The light isolation plate 133 is used to isolate the light emitted by adjacent LED lamp posts 1311 to prevent light crosstalk.

[0078] In some embodiments, the status display assembly is sealed against the inner housing cover 13. During installation, first place the light guide 132 in the mounting slot inside the inner housing cover 13. Then, position the status display circuit board 131 behind the light guide 132 and screw the status display circuit board 131 to the inner housing cover 13. Then, place the light barrier 133 in front of the light guide 132, so that the light guide 132 and the light barrier 133 are interlocked. Finally, press the outer housing cover 12 onto the outside of the inner housing cover 13, securing the light guide 132 and the light barrier 133. Optionally, to mitigate the impact of a dropped battery pack, the light barrier 133 may also be an elastic member.

[0079] Figure 10 This is a cross-sectional view of a battery pack according to one embodiment of the present invention when the inner shell cover and the battery cell assembly are installed in the outer shell body and the inner shell body.

[0080] like Figure 2 and Figure 10 As shown, considering the waterproof requirement, the battery pack is not provided with a vent, and the battery cell assembly 2 is in a sealed state. For safety reasons, the battery pack 100 also includes a balancing valve 134 provided on the inner shell cover 13. The balancing valve 134 is used to balance the internal and external air pressures of the inner shell. In some embodiments, the balancing valve 134 is configured as an opening covered with a breathable membrane, which can balance the internal and external air pressures when the pressure difference between the inside and outside of the inner shell is large. Optionally, the breathable membrane is provided with four or more layers to increase rigidity. Optionally, ribs are provided on the inner shell cover 13 to support and compress the breathable membrane.

[0081] In some embodiments, the battery pack 100 further includes a pressure relief valve 135 disposed on the inner shell cover 13, and the pressure relief valve 135 is used to relieve the pressure inside the inner shell. The pressure relief valve 135 includes an inner core 1352 mounted on an opening (not shown) of the inner shell cover 13. When the battery cell 23 fails and the pressure inside the sealed inner shell is too high, for example, when the pressure exceeds a preset threshold, the inner core 1352 will be pushed open from the inside to relieve pressure to prevent a safety accident. Optionally, the pressure relief valve 135 further includes a sealing ring 1351, which is disposed between the opening of the inner shell cover 13 and the inner core 1352 to achieve sealing at the opening of the inner shell cover 13.

[0082] Figures 10A to 10E Schematic diagram of the installation of the battery cell assembly and the shell of a battery pack according to one embodiment of the present invention.

[0083] in, Figure 10B It is along Figure 10A A1-A1 line sectional view, Figure 10C It is along Figure 10A A2-A2 line sectional view, Figure 10DIt is along Figure 10A B1-B1 line cross-sectional view, Figure 10E It is along Figure 10A Sectional view along line B2-B2.

[0084] like Figure 4 、 Figure 5 、 Figure 10A and Figure 10B As shown, the top of the battery cell assembly 2 is limited by the rectangular column 213 and the shell body 11. Optionally, the rectangular column 213 is set on the control circuit board 260.

[0085] The battery core assembly 2 is pressed against the housing body 11 by the long screw 121 to ensure that the battery core assembly 2 does not move in the Z axis.

[0086] like Figure 10A and Figure 10C As shown, the housing body 11 and the housing cover 12 are assembled and connected by 10 screws 122 evenly arranged around the circumference.

[0087] The battery cell assembly 2 and the housing body 11 are limited by four positioning posts 119 .

[0088] The entire joint between the housing body 11 and the housing cover 12 is engaged by a stop 123 .

[0089] like Figure 10A and Figure 10E As shown, the housing body 11 is further provided with a handle 125, and the handle 125 can pivot relative to the housing body 11. Optionally, the maximum pivot angle of the handle 125 is 90 degrees.

[0090] Figure 11 1 is an exploded view of a cell assembly of a battery pack according to an embodiment of the present invention. Figure 12 yes Figure 11 Please also refer to the diagram of another perspective of Figure 2 、 Figure 3 、 Figure 5 、 Figure 11 and Figure 12 The battery cell assembly 2 further includes a bracket 22 and a plurality of battery cells 23 electrically connected to each other, wherein the bracket 22 is used to fix the battery cells 23. Optionally, the battery cells 23 are configured as cylindrical battery cells.

[0091] In some embodiments, as Figure 12As shown, the battery cell assembly 2 includes two battery cell assemblies 20 and 21 that are electrically connected to each other. The battery cell assembly 20 includes 35 battery cells 23, and the battery cell assembly 21 includes 40 battery cells 23. Every 5 battery cells 23 are connected in parallel to form a group of battery cell units. The battery cell assembly 20 includes 7 groups of battery cell units connected in series, and the battery cell assembly 21 includes 8 groups of battery cell units connected in series, and the battery cell assembly 20 is connected in series with the battery cell assembly 21. Optionally, the rated voltage of each battery cell 23 is 3.6V, and the rated voltage of the battery pack 100 is 54V. Optionally, the capacity of each battery cell 23 is 5Ah, and the capacity of the battery pack 100 is 25Ah.

[0092] The battery cell assembly 2 also includes at least one connecting piece for electrically connecting the battery cells. The connecting piece is welded to the electrode of the battery cell 23 to achieve electrical connection between the battery cells. In some embodiments, the connecting piece includes a first connecting piece 241 and a second connecting piece 242, which are respectively arranged at both ends of the battery cell 23. The first connecting piece 241 and the second connecting piece 242 are respectively provided with output ends 2411 and 2421, and the output ends 2411 and 2421 are connected to the control circuit board 260 to output the total positive end and the total negative end of the battery cell assembly. Optionally, as Figure 11 As shown, the first connecting piece 241 includes 9 connecting pieces, and the second connecting piece 242 includes 8 connecting pieces, and each connecting piece connects one or two groups of battery cell units.

[0093] The battery cell assembly 2 also includes a first insulating sheet 251 and a second insulating sheet 252. The first insulating sheet 251 is disposed outside the first connecting sheet 241 and affixed to the end of the battery cell 23. The second insulating sheet 252 is disposed outside the second connecting sheet 242 and affixed to the other end of the battery cell 23. The first insulating sheet 251 and the second insulating sheet 252 are used for insulation and protection between the battery cells 23.

[0094] like Figure 5 As shown, the battery cell assembly 2 also includes a control circuit board 260 to control the charging and discharging of the battery cell assembly 2. The battery pack 100 also includes a circuit board packaging box 214. The control circuit board 260 is encapsulated within the circuit board packaging box 214 to prevent moisture from entering the control circuit board. In some embodiments, the circuit board packaging box 214 is filled with glue to encapsulate the control circuit board 260.

[0095] The battery cell assembly 2 also includes a flexible circuit board 270, which is used to detect electrical parameters of the battery cell 23, such as temperature and voltage. The flexible circuit board 270 is connected to the control circuit board 260 and the first and second connecting pieces 241 and 242. Optionally, two flexible circuit boards 270 are provided, one on the outside of the corresponding first and second insulating sheets 251 and 252. Placing the flexible circuit boards 270 on the outside of the first and second insulating sheets 251 and 252 prevents moisture from entering the interior of the battery cell assembly 2 through the weld between the flexible circuit boards 270 and the control circuit board 260.

[0096] In some embodiments, the battery cell assembly 2 further includes a temperature sensor (not shown) for detecting the temperature of the battery cell 23. Specifically, the temperature sensor is disposed on the flexible circuit board 270 and extends into the circumference of the battery cell 23 through an opening (not shown) provided in the flexible circuit board 270. Thermally conductive silicone grease is applied around the temperature sensor to better detect the actual temperature of the battery cell 23.

[0097] Figure 13 FIG. 1 is a schematic diagram of the arrangement of cell components in a battery pack according to an embodiment of the present invention, wherein: Figure 13 It is along Figure 10E The cross-sectional view of CC, Figure 14 yes Figure 13 The enlarged schematic diagram of the middle I area, Figure 15 yes Figure 13 The enlarged schematic diagram of the middle II area, Figure 16 and Figure 17 is a schematic diagram of the arrangement of a row of battery cell groups in some embodiments of the present invention, Figure 18 and Figure 19 is a schematic diagram of the arrangement of multiple rows of battery cell groups in some embodiments of the present invention, Figure 20 2 is a schematic diagram of the arrangement of the battery cell components in a battery pack according to an embodiment of the present invention. Please refer to it. The axes of the multiple battery cells 23 are arranged in parallel and arranged in an array in a first direction X and a second direction Y perpendicular to the axes of the battery cells 23.

[0098] Battery cells generate a significant amount of heat rapidly during charging and discharging. When cells are arranged in more than two rows, the cells on the inside of the casing are surrounded by other cells. During high-power discharge, the cells on the outside of the casing dissipate heat better than those on the inside. This results in a significant temperature difference between the inner and outer cells, which can affect the battery pack's lifespan.

[0099] To address the above issues, in some embodiments, the plurality of battery cells 23 are arranged into multiple columns of battery cell groups 230. Each column of battery cell groups 230 extends along the first direction X, and the multiple columns of battery cell groups 230 are spaced apart in the second direction Y. In the first direction X, the distance between two adjacent battery cells 23 in at least one column decreases from the middle toward both ends, and / or, in the second direction Y, the distance between two adjacent columns of battery cell groups 230 decreases from the middle toward both ends.

[0100] Typically, the temperature of the battery cell in the middle is relatively high, while the temperature of the battery cells at the ends is relatively low. Arranging multiple battery cells in this manner can increase the volume of air surrounding the hotter battery cell, allowing the surrounding air to absorb more heat. This balances the temperature of each battery cell and avoids large temperature differences between the cells.

[0101] In some embodiments, the number of cells 23 in at least one column of cell groups 230 is N, where N is an odd number and is greater than or equal to 5. In the first direction X, the distances between two cells 23 symmetrically distributed around the middle cell 23 in the same column and their adjacent cells 23 are equal. It should be noted that the distances described herein refer to the distances between the centers of the cells, and equality is not necessarily absolute equality, but equality within a certain range, for example, within a range of plus or minus 1 mm. This arrangement ensures that when the number of cells in a column of cell groups is an odd number, the cells are symmetrically arranged, facilitating the design and installation of the cell group.

[0102] In one embodiment, if Figure 16 As shown, a row of cell groups contains seven cells, namely 23A, 23B, 23C, 23D, 23E, 23F, and 23G. The middle cell in this row of cells is 23D. In a first direction X, the distance between two adjacent cells in the row decreases from middle cell 23D toward both ends. In the first direction X, the distances between two cells symmetrically distributed around middle cell 23D and their respective adjacent cells in the row are equal. For example, the distance between cell 23C and middle cell 23D is equal to the distance between cell 23E and middle cell 23D. For another example, the distance between cell 23F and cell 23E is equal to the distance between cell 23C and cell 23B.

[0103] Of course, in other embodiments, there may be multiple middle cells, and the middle cell is not necessarily the conventional one located in the middle. Specifically, the cell with the largest distance from the adjacent cells is called the middle cell.

[0104] In some embodiments, the number of battery cells 23 in at least one column of battery cell groups 230 is N, where N is an even number and is greater than or equal to 4. The number of middle battery cells 23 in the same column is N1, where N1 is an even number and is greater than or equal to 2, and N1 is less than N. In the first direction X, the distance between adjacent middle battery cells 23 in the same column is greater than the distance between other adjacent battery cells 23. This arrangement ensures that when the number of battery cells in each column is an even number, the battery cells in each column are symmetrically arranged with the middle battery cell as the center, facilitating the design and installation of the battery cell assembly.

[0105] In one embodiment, if Figure 17 As shown, a row of cell groups has eight cells, namely 23A', 23B', 23C', 23D', 23E', 23F', 23G', and 23H'. The middle cells in the row of cell groups are 23D' and 23E'. In a first direction X, the distance between adjacent cells 23D' and 23E' in the row is greater than the distance between other adjacent cells. For example, the distance between middle cells 23D' and 23E' is greater than the distance between cells 23C' and 23B'.

[0106] In some embodiments, the number of cells 23 in at least one column of cell groups 230 is N, where N is an even number and is greater than or equal to 6. The number of middle cells 23 in the same column is N1, where N1 is an even number and is greater than or equal to 4. In the first direction X, the distances between adjacent middle cells 23 in the same column are equal. It should be noted that when the number of cells 23 in a column is even, the definition of middle cells 23 is not necessarily the conventional two located in the middle, but may be multiple. Specifically, the cells 23 with the greatest distance between them are referred to as middle cells. Optionally, in the first direction X, two cells 23 symmetrically distributed around the middle cell 23 in the same column are equidistant from their respective adjacent cells 23.

[0107] In some embodiments, the number of rows of cell groups 230 is M, where M is an odd number and is greater than or equal to 5. In the second direction Y, the distances between two rows of cell groups symmetrically distributed around the middle row of cell groups and the cell groups in their adjacent rows are equal. This arrangement ensures that when the number of rows of cell groups is an odd number, the multiple rows of cell groups are symmetrically arranged around the middle row of cell groups, facilitating the design and installation of the cell assembly.

[0108] In one embodiment, if Figure 18As shown, the cell assembly has five rows of cell groups, namely 230A, 230B, 230C, 230D, and 230E. The middle row of cell groups is 230C. In the second direction Y, the distance between two adjacent rows of cell groups decreases from the middle row of cell group 230C toward both ends. In the second direction Y, the distances between two rows of cell groups symmetrically distributed around the middle row of cell group 230C and their respective adjacent cell groups are equal. For example, the distance between cell group 230B and the middle row of cell group 230C is equal to the distance between cell group 230D and the middle row of cell group 230C. For another example, the distance between cell group 230A and cell group 230B is equal to the distance between cell group 230D and cell group 230E.

[0109] Of course, in other embodiments, there may be multiple middle column cell groups, and the middle column cell group is not necessarily the conventional middlemost column cell group. Specifically, the cell group with the largest distance from the adjacent column cell groups is called the middle column cell group.

[0110] In some embodiments, the number of rows of cell groups 230 is M, where M is an even number and is greater than or equal to 4. The number of cell groups 230 in the middle row is M1, where M1 is an even number and is greater than or equal to 2. In the second direction Y, the distance between adjacent cell groups in the middle row is greater than the distance between cell groups in other adjacent rows. This arrangement ensures that when the number of rows of cell groups is even, multiple rows of cell groups are symmetrically arranged with the middle cell group as the center, facilitating the design and installation of the cell assembly.

[0111] In one embodiment, if Figure 19 As shown, the cell assembly has six rows of cell groups, namely 230A', 230B', 230C', 230D', 230E', and 230F'. The middle row of cell groups in this cell assembly is 230C' and 230D'. In the second direction Y, the distance between adjacent rows of cell groups 230C' and 230D' is greater than the distance between other adjacent rows of cell groups. For example, the distance between the middle row of cell groups 230C' and 230D' is greater than the distance between cell groups 230A' and 230B'.

[0112] In some embodiments, the number of rows of the battery cell groups 230 is M, which is an even number and is greater than or equal to 6. The number of battery cell groups 230 in the middle row is M1, which is an even number and is greater than or equal to 4. In the second direction Y, the distances between adjacent battery cell groups 230 in the middle row are equal.

[0113] In some embodiments, the battery pack includes at least two cell assemblies, which are spaced apart along the second direction Y. The distance between two adjacent rows of cell groups in adjacent cell assemblies is L, where L is greater than the distance between two adjacent rows of cell groups in each adjacent cell assembly. Because the adjacent rows of cell groups in adjacent cell assemblies are generally closer to the center of the housing and have higher temperatures, this arrangement can balance the temperatures between the cells.

[0114] Specifically, such as Figure 20 As shown, the battery cell assembly 2 includes two battery cell assemblies 20 and 21. The two battery cell assemblies 20 and 21 are fastened together, and L is greater than L4 and L5.

[0115] by Figure 20 Taking one of the cell assemblies 20 in the example, the cell assembly 20 includes five columns of cell groups 230, and each column of cell group 230 includes eight cell 23. Optionally, within the same column of cell group 230, the middle cell is the third to sixth cell from top to bottom in the first direction X. In the first direction X, the distance L1 between the third, fourth, fifth, and sixth cell 23 is equal, and the distance between the second and third cell 23 is equal to the distance between the sixth and seventh cell 23, both of which are L2. The distance between the first and second cell 23 is equal to the distance between the seventh and eighth cell 23, both of which are L3. Optionally, L1>L2>L3.

[0116] Similarly, taking the cell assembly 20 as an example, the middle row of cell groups is the third row from left to right in the second direction Y. In the second direction Y, the distances between the cell groups 230 in the second, third, and fourth rows are equal, all L4. The distances between the cell groups 230 in the first and second rows are equal to the distances between the cell groups 230 in the fourth and fifth rows, both L5. Optionally, L4 > L5.

[0117] Optionally, in the second direction Y, the distances between the two columns of cell groups 230 symmetrically distributed around the middle column of cell groups 230 and the cell groups 230 in their adjacent columns are equal.

[0118] Optionally, the distance between the center of at least one battery cell 23 and the center of an adjacent battery cell 23 in the same column is not equal to the distance between the centers of adjacent battery cells 23 in the adjacent column. Figure 14As shown, taking cell 23a as an example, the distances S1 and S2 between cell 23a and the centers of adjacent cells 23b and 23c in the same column are not equal to the distances S3, S4, S5, and S6 between the centers of adjacent cells 23d, 23e, 23f, and 23g in adjacent columns. It should be noted that S1 and S2 can be partially equal to or completely different from S3, S4, S5, and S6. In some embodiments, the distance between the center of any cell 23 and the center of an adjacent cell 23 in the same column is not equal to the distance between the centers of adjacent cells 23 in adjacent columns.

[0119] Optionally, the cells 23 of two adjacent columns of cell groups 230 are arranged in a staggered arrangement. In other embodiments, the cells 23 may also be arranged in a straight line. It should be noted that staggered arrangement means that the line connecting the center of the cell in one column of cell groups and the center of the adjacent cell in the adjacent column of cell groups intersects the second direction Y, and straight arrangement means that the line connecting the center of the cell in one column of cell groups and the center of the adjacent cell in the adjacent column of cell groups is arranged parallel to the second direction Y.

[0120] Optionally, when the battery cell assemblies are arranged in a staggered arrangement, the distance between the battery cells in each column of the battery cell group and the adjacent battery cells in the adjacent column is greater than the distance between the battery cells and the adjacent battery cells in the same column.

[0121] In order to match the arrangement of the battery cells, the arrangement positions of the connecting pieces in the above embodiment also need to be arranged accordingly, which will not be described in detail here.

[0122] In some embodiments, the bracket 22 is made of a thermally conductive material, and the thermal conductivity of the bracket 22 is greater than 1 W / mK. The bracket is made of a thermally conductive material to better transfer heat from the battery cell, thereby improving the performance of the battery pack.

[0123] like Figure 12As shown, the bracket 22 includes a first bracket 221 and a second bracket 222 arranged opposite each other. The first bracket 221 and the second bracket 222 enclose a plurality of first mounting portions 223 and second mounting portions 224 for securing the battery cells 23. Optionally, the first mounting portion 223 fully encloses the circumference of the battery cells, while the second mounting portion 224 partially encloses the circumference of the battery cells. Specifically, both the first bracket 221 and the second bracket 222 include a first mounting portion 223 and a second mounting portion 224. It should be noted that full encapsulation as described herein does not necessarily mean 100%; full encapsulation can also be achieved within a certain range, for example, encompassing 80% or more of the surface area of the battery cell circumference. This arrangement allows for selecting the appropriate bracket encapsulation method based on the varying temperatures of the battery cells at different locations, thereby controlling the temperature differences between the battery cells. Optionally, the first mounting portion 223 and the second mounting portion 224 are configured as cylindrical walls that match the basic shape of the battery cells 23. The first mounting portion 223 and the second mounting portion 224 define a receiving cavity within which the battery cells 23 are at least partially housed.

[0124] It should be noted that the number of first mounting portions and second mounting portions does not necessarily have to be exactly equal to the number of battery cells. The number of first mounting portions and second mounting portions can be greater than the number of battery cells. This facilitates the manufacture of the bracket and allows the bracket to be adapted to other battery packs with different numbers of battery cells, i.e., the bracket is compatible with different battery packs.

[0125] In some embodiments, a plurality of first mounting portions 223 are arranged into a plurality of columns of first group mounting portions (not shown), each column of first group mounting portions extends along the first direction X, and the plurality of columns of first group mounting portions are spaced apart in the second direction Y. In the first direction X, the distance between two adjacent first mounting portions 223 in the same column decreases from the middle to both ends, and / or, in the second direction Y, the distance between two adjacent columns of first group mounting portions decreases from the middle to both ends. Such an arrangement can match the arrangement of the battery cells in the aforementioned embodiments. In some embodiments, in the first direction X and / or the second direction Y, the first mounting portion 223 wraps the battery cell 23 located in the middle, and the second mounting portion 224 wraps the battery cells 23 located at both ends. Normally, the temperature of the battery cell located in the middle is relatively high, and the temperature of the battery cells located at both ends is relatively low. Such an arrangement can balance the temperatures of the battery cells.

[0126] Optionally, the surface area of the second mounting portion 224 surrounding the battery cells 23 decreases from the middle to the ends in the first direction X and / or the second direction Y. Similarly, in general, the temperature of the battery cells decreases from the middle to the ends, so the surface area of the second mounting portion 224 surrounding the battery cells decreases accordingly, which can also balance the temperature of each battery cell.

[0127] Optionally, the second mounting portion 224 wraps around a portion of the circumference of both axial ends of the battery core 23. Wrapping the axial ends of the battery core can enable the bracket to better fix the battery core, making the battery core support more reliable.

[0128] In this document, directional terms such as "up," "down," "left," "right," "front," and "back" are defined based on the positions of structures in the accompanying drawings and their relative positions to each other, for the sake of clarity and convenience in presenting the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second," etc., used herein, are used solely for distinctions and are not intended to limit quantity or order.

[0129] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A battery pack (100), comprising a housing (1) and at least one battery cell assembly (2) housed in the housing (1), wherein the battery cell assembly (2) comprises a bracket (22) and a plurality of battery cells (23) electrically connected to each other, wherein the bracket (22) is used to fix the battery cells (23), and is characterized in that: The axial directions of the plurality of battery cells (23) are arranged in parallel and arranged in an array in a first direction (X) and a second direction (Y) perpendicular to the axial directions of the battery cells (23), wherein the plurality of battery cells (23) are arranged into a plurality of columns of battery cell groups (230), each column of the battery cell groups (230) extends along the first direction (X), and the plurality of columns of the battery cell groups (230) are arranged at intervals in the second direction (Y); in the first direction (X), the distance between two adjacent battery cells (23) in at least one column decreases from the middle to both ends, and / or, in the second direction (Y), the distance between two adjacent columns of the battery cell groups (230) decreases from the middle to both ends.

2. The battery pack (100) according to claim 1, characterized in that The number of battery cells (23) in at least one column of the battery cell group (230) is N, N is an odd number, N is greater than or equal to 5, and in the first direction (X), the distances between two battery cells symmetrically distributed around the middle battery cell in the same column and their adjacent battery cells are equal.

3. The battery pack (100) according to claim 1, characterized in that The number of battery cells (23) in at least one column of the battery cell group (230) is N, N is an even number, N is greater than or equal to 4, the number of middle battery cells in the same column is N1, N1 is an even number, N1 is greater than or equal to 2, and in the first direction (X), the distance between adjacent middle battery cells in the same column is greater than the distance between other adjacent battery cells.

4. The battery pack (100) according to claim 3, characterized in that: The number of battery cells (23) in at least one column of the battery cell group (230) is N, N is an even number, N is greater than or equal to 6, the number of middle battery cells in the same column is N1, N1 is an even number, N1 is greater than or equal to 4, and in the first direction (X), the distances between adjacent middle battery cells in the same column are equal.

5. The battery pack (100) according to claim 3, characterized in that: In the first direction (X), the distances between two battery cells symmetrically distributed around the middle battery cell in the same column and their adjacent battery cells are equal.

6. The battery pack (100) according to claim 1, characterized in that The number of columns of the battery cell groups (230) is M, which is an odd number and is greater than or equal to 5. In the second direction (Y), the distances between the two columns of battery cell groups symmetrically distributed with the middle column of battery cell groups as the center and the battery cell groups in the adjacent columns are equal.

7. The battery pack (100) according to claim 6, characterized in that: The number of rows of the battery cell groups (230) is M, which is an even number and is greater than or equal to 4; the number of battery cell groups in the middle rows is M1, which is an even number and is greater than or equal to 2; and in the second direction (Y), the distance between adjacent battery cell groups in the middle rows is greater than the distance between battery cell groups in other adjacent rows.

8. The battery pack (100) according to claim 7, characterized in that: The number of rows of the battery cell groups (230) is M, which is an even number and is greater than or equal to 6. The number of battery cell groups in the middle rows is M1, which is an even number and is greater than or equal to 4. In the second direction (Y), the distances between adjacent battery cell groups in the middle rows are equal.

9. The battery pack (100) according to claim 8, characterized in that: In the second direction (Y), the distances between the two columns of battery cell groups symmetrically distributed with the middle column of battery cell groups as the center and the battery cell groups in their respective adjacent columns are equal.

10. The battery pack (100) according to claim 1, characterized in that: The distance between the center of at least one of the battery cells and the center of an adjacent battery cell in the same column is not equal to the distance between the centers of adjacent battery cells in the adjacent column.

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