Parallel battery pack, lithium ion battery and assembling method of parallel battery pack

Abstract

The invention provides a parallel battery pack, a lithium ion battery and an assembling method of the parallel battery pack. The parallel battery pack comprises a plurality of cylindrical battery cells which are sequentially arranged along the axes of the cylindrical battery cells, and the adjacent ends of every two adjacent cylindrical battery cells are each provided with a positive tab area and a negative tab area. The current collecting component is located between the two adjacent cylindrical battery cells, the current collecting component comprises a positive current collecting disc and a negative current collecting disc, the positive current collecting disc is used for connecting the positive lug regions of the two adjacent cylindrical battery cells, and the negative current collecting disc is used for connecting the negative lug regions of the two adjacent cylindrical battery cells, so that the two adjacent cylindrical battery cells are arranged in parallel; the positive collector plate and the negative collector plate are both arranged in a bendable manner, and one of the two adjacent cylindrical battery cells is superposed on the other one of the two adjacent cylindrical battery cells. According to the lithium ion battery provided by the technical scheme of the invention, the whole manufacturing process is simpler and more reliable while the energy density is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular, to a parallel battery pack, a lithium-ion battery, and an assembly method for the parallel battery pack. Background Art

[0002] The core of a traditional cylindrical battery has an end tab structure at both ends. Only a single core is contained in a single cylindrical battery case, and then several cylindrical batteries are finally assembled into a PACK (battery pack). This method will result in too many structural components required for the PACK (battery pack), restricting the effective improvement of the energy density.

[0003] If the multi-core parallel method is used to increase the energy density of cylindrical batteries, the traditional solutions mostly refer to the process of square batteries and adopt the multi-core parallel mode, that is, several cylindrical cores are arranged side by side, and the positive tabs and negative tabs are located at both ends respectively. However, since the cores are cylindrical, a case that conforms to the shape required for the multi-core parallel arrangement needs to be designed, and the manufacturing process is complex. Summary of the Invention

[0004] The main object of the present invention is to provide a parallel battery pack, a lithium-ion battery, and an assembly method for the parallel battery pack, so that the above-mentioned lithium-ion battery can make the entire manufacturing process simpler and more reliable while improving the energy density.

[0005] To achieve the above object, the present invention provides a parallel battery pack, including: a plurality of cylindrical cores arranged in sequence along the axis of the cylindrical core, and adjacent end portions of two adjacent cylindrical cores both have a positive tab area and a negative tab area; a current collecting member located between two adjacent cylindrical cores, the current collecting member includes a positive current collecting plate and a negative current collecting plate, the positive current collecting plate is used to connect the positive tab areas of two adjacent cylindrical cores, and the negative current collecting plate is used to connect the negative tab areas of two adjacent cylindrical cores, so that two adjacent cylindrical cores are arranged in parallel. Among them, the positive current collecting plate and the negative current collecting plate are both bendably arranged, and one of the two adjacent cylindrical cores is stacked on the other of the two adjacent cylindrical cores.

[0006] In the above technical solution, the positive electrode current collector plate is used to connect the positive electrode tab areas of two adjacent cylindrical battery cells, and the negative electrode current collector plate is used to connect the negative electrode tab areas of two adjacent cylindrical battery cells, so that parallel connection of multiple cylindrical battery cells can be achieved. By bending the positive electrode current collector plate and the negative electrode current collector plate, stacking of multiple cylindrical battery cells can be realized, so that multiple cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cell. In this way, on the one hand, compared with the traditional cylindrical battery PACK that requires multiple structural parts to assemble a single battery cell, the present invention can reduce the number of structural parts required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density. On the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not need to customize a housing with a specific shape, and only needs to use a traditional cylindrical housing to accommodate multiple cylindrical battery cells, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable.

[0007] Further, the cylindrical battery cell includes a battery cell body. The battery cell body has a battery cell through hole extending along its own axial direction. The positive electrode tab area is arranged on the battery cell body and is located on the periphery of the battery cell through hole. The positive electrode current collector plate is provided with two positive welding areas, and the two positive welding areas are respectively welded to the positive electrode tab areas of two adjacent battery cells. Each positive welding area is provided with a positive electrode through hole, and the two positive electrode through holes are correspondingly communicated with the battery cell through holes of two adjacent battery cells.

[0008] In the above technical solution, the two positive welding areas on the positive electrode current collector plate are welded to the positive electrode tab areas of two adjacent battery cells, realizing the parallel connection of two adjacent cylindrical battery cells. And through the communication between the positive electrode through hole and the battery cell through hole, it allows the electrolyte to better infiltrate into the interiors of two adjacent battery cell bodies, thereby ensuring the uniform progress of the electrochemical reaction during the charging and discharging process of the battery, and improving the performance and lifespan of the battery.

[0009] Further, the positive electrode current collector plate has a positive electrode bending part. The positive electrode bending part is located between the two positive welding areas. The positive electrode bending part has a positive electrode bending line, and the positive electrode current collector plate can be bent along the positive electrode bending line. The connection line passing through the centers of the two positive electrode through holes forms an included angle with the positive electrode bending line.

[0010] In the above technical solution, by bending the positive electrode current collector plate, one end of the battery cell body can be stacked on one end of another battery cell body, enabling the stacking of two adjacent cylindrical battery cells, so as to arrange multiple cylindrical battery cells more closely, effectively utilize the space inside the battery pack, and improve the energy density. And the included angle formed between the connection line passing through the centers of the two positive electrode through holes and the positive electrode bending line can avoid bending to the positive electrode through hole, ensuring that the battery cell through hole can still maintain good electrical connection after bending, avoiding connection failure or breakage caused by bending, and improving the reliability of the battery pack.

[0011] Furthermore, the positive current collector plate is arranged symmetrically about the positive bending line; and / or, the positive bending portion includes a plurality of positive bending holes arranged in sequence, and the connection line of the centers of the plurality of positive bending holes forms the positive bending line.

[0012] In the above technical solution, for the mirror-symmetrical positive current collector plate, after the positive current collector plate is bent, it can ensure that the two positive through holes can be aligned, so that the two cell through holes can be connected through the two positive through holes, to ensure the electrical connection path between two adjacent cylindrical cells, thereby ensuring that all cells have the same electrical performance when connected in parallel, and improving the overall consistency of the battery pack; and the setting of a plurality of positive bending holes makes it easier for the positive current collector plate to be bent along the connection line of the centers of these holes, which not only ensures the accuracy of bending, but also simplifies the bending operation process and improves the assembly efficiency of the battery pack.

[0013] Furthermore, the negative tab area is arranged on the cell body and located on the outer peripheral side of the positive tab area. Along the radial direction of the cell body, the positive tab area and the negative tab area are arranged at intervals to form an external tabless area. The negative current collector plate is located on the outer periphery of the positive current collector plate, and there is a gap between the negative current collector plate and the positive current collector plate. The negative current collector plate is provided with two negative welding areas, and the two negative welding areas are respectively welded to the negative tab areas of two adjacent cylindrical cells.

[0014] In the above technical solution, on the one hand, the positive tab area and the negative tab area are arranged at intervals, and the external tabless area formed between them effectively prevents the direct contact between the positive and negative tabs, avoids the risk of internal short circuit, and significantly improves the safety of the battery pack; on the other hand, the positive current collector plate and the negative current collector plate are kept at a gap, which not only realizes electrical isolation, but also ensures the insulation performance between the positive and negative poles, enhancing the electrical safety of the battery pack; on the third hand, by providing two negative welding areas on the negative current collector plate, the negative tab areas of two adjacent cells can be welded simultaneously, realizing the high efficiency of parallel connection, simplifying the electrical assembly process of the battery pack, and improving the production efficiency.

[0015] Furthermore, the negative current collector plate has a negative bending portion, the negative bending portion is located between the two negative welding areas, the negative bending portion has a negative bending line, and the negative current collector plate can be bent along the negative bending line. The connection line passing through the centers of the two cylindrical cells is arranged at an angle with the negative bending line.

[0016] In the above technical solution, by bending the negative current collector plate, one end of the cell body can be stacked on one end of another cell body, and two adjacent cylindrical cells can be stacked, so as to arrange multiple cylindrical cells more closely, effectively utilize the space in the battery pack, and improve the energy density.

[0017] Furthermore, the negative current collector plate is arranged in mirror symmetry with respect to the negative bending line; and / or, the negative bending portion includes a plurality of negative bending holes arranged in sequence, and the connection line of the centers of the plurality of negative bending holes forms the negative bending line.

[0018] In the above technical solution, the mirror symmetry design helps to ensure uniform stress distribution on both sides of the current collector plate during the bending process, avoiding material deformation or fracture caused by unilateral stress concentration, and improving the structural stability and reliability of the negative current collector plate; and the symmetric arrangement ensures that the electrical connection paths and resistances between all negative tab areas and the negative current collector plate are consistent, helping to improve the overall electrical performance consistency of the battery pack and avoiding performance fluctuations caused by connection differences; and the setting of a plurality of negative bending holes makes it easier for the negative current collector plate to be bent along the connection line of the centers of these holes, ensuring the accuracy of bending, simplifying the bending operation process, and improving the assembly efficiency of the battery pack.

[0019] Furthermore, the parallel battery pack further includes at least one insulating member located between the positive current collector plate and the negative current collector plate. The insulating member is correspondingly arranged with the external tabless area. One end of the insulating member is connected to the positive current collector plate, and the other end of the insulating member is connected to the negative current collector plate to form an integrated current collector plate structure, wherein the insulating member is made of insulating material.

[0020] In the above technical solution, the setting of the insulating member effectively isolates the positive current collector plate and the negative current collector plate, avoiding direct contact between them, significantly improving the electrical safety of the battery pack, and preventing short-circuit phenomena caused by direct contact of the electrode plates; and the integrated current collector plate structure reduces the alignment difficulty of the positive and negative current collector plates during assembly, simplifies the battery assembly steps, reduces the error rate and complexity in the manufacturing process of the battery pack, and improves the production efficiency.

[0021] Furthermore, at least one negative stress hole is provided on the negative current collector plate; and / or, at least one positive stress hole is provided on the positive current collector plate.

[0022] In the above technical solution, the stress holes provided on the current collector plate can effectively release the thermal stress and mechanical stress generated during the welding process, avoid deformation or cracks caused by stress concentration, and enhance the structural stability and reliability of the current collector plate; and the design of the stress holes can reduce the material usage of the current collector plate, thereby reducing the weight of the battery pack, which is particularly important for applications such as portable devices or electric vehicles that pursue lightweight design.

[0023] Further, along the arrangement direction of the plurality of cylindrical battery cells, one end of the first cylindrical battery cell among the plurality of cylindrical battery cells has a positive tab area and a negative tab area, and the other end of the first cylindrical battery cell among the plurality of cylindrical battery cells has a negative connection area; along the arrangement direction of the plurality of cylindrical battery cells, one end of the last cylindrical battery cell among the plurality of cylindrical battery cells has a positive tab area and a negative tab area, and the other end of the last cylindrical battery cell among the plurality of cylindrical battery cells has a positive connection area; both ends of the remaining cylindrical battery cells among the plurality of cylindrical battery cells are provided with a positive tab area and a negative tab area.

[0024] In the above technical solution, the negative connection area and the positive connection area can be directly externally electrically connected, simplifying the construction of the parallel circuit of the battery pack and improving the efficiency and reliability of the electrical connection; and both ends of the intermediate battery cells are provided with positive and negative tab areas, enabling the battery cells to be closely arranged, reducing the gap between the battery cells, improving the space utilization rate of the battery pack, and thus increasing the overall energy density of the battery pack.

[0025] Further, the plurality of cylindrical battery cells include a first type of battery cell wound from a first laminated unit. Along the length direction of the first laminated unit, the first laminated unit is divided into a first area, a second area, a third area, and a fourth area arranged in sequence. Along the width direction of the first laminated unit, the first laminated unit has a first side and a second side arranged opposite to each other; a positive tab is provided on the first side of the second area to form a positive tab area; a negative tab is provided on the first side of the fourth area to form a negative tab area; a positive tab is provided on the second side of at least one of the second area, the third area, and the fourth area to form a positive connection area.

[0026] In the above technical solution, by providing a positive tab on the first side of the second area S2 to form a positive tab area, providing a negative tab on the first side of the fourth area S2 to form a negative tab area, and providing a positive connection area on the second sides of the second area S2, the third area S3, and the fourth area S4, parallel connection with other cylindrical battery cells can be achieved, and the cylindrical battery cell can also be connected to an external power source or an external device to be powered.

[0027] Further, the plurality of cylindrical battery cells include a second type of battery cell wound from a second laminated unit. Along the length direction of the second laminated unit, the second laminated unit is divided into a first area, a second area, a third area, and a fourth area arranged in sequence. Along the width direction of the second laminated unit, the second laminated unit has a first side and a second side arranged opposite to each other; positive tabs are provided on both the first side and the second side of the second area to form positive tab areas on both the first side and the second side, and negative tabs are provided on both the first side and the second side of the fourth area to form negative tab areas on both the first side and the second side.

[0028] In the above technical solution, the positive and negative electrode tabs are respectively distributed on both sides of the battery cell, which can simplify the welding process of the current collector plate, avoid the problems of occlusion or difficulty in reaching that may be encountered during single-sided welding, improve the welding quality and production efficiency; and the double-sided tab design allows the battery cells to be arranged and connected in various ways, improving the flexibility of parallel connection of the battery cells, helping to optimize the layout of the battery cells inside the battery pack, and achieving a higher energy density.

[0029] Further, the plurality of cylindrical battery cells include a third type of battery cell wound from a third stacked unit. Along the length direction of the third stacked unit, the third stacked unit is divided into a first region, a second region, a third region, and a fourth region arranged in sequence. Along the width direction of the third stacked unit, the third stacked unit has a first side and a second side arranged opposite to each other; a positive electrode tab is provided on the first side of the second region to form a positive electrode tab region; a negative electrode tab is provided on the first side of the fourth region to form a negative electrode tab region; a negative electrode tab is provided on the second side of at least one of the second region, the third region, and the fourth region to form a negative electrode connection region.

[0030] In the above technical solution, by providing a positive electrode tab on the first side of the second region S2 to form a positive electrode tab region, providing a negative electrode tab on the first side of the fourth region S2 to form a negative electrode tab region, and providing a negative electrode connection region on the second side of the second region S2, the third region S3, and the fourth region S4, parallel connection with other cylindrical battery cells can be achieved, and the cylindrical battery cells can also be connected to an external power source or an external device to be powered.

[0031] According to another aspect of the present invention, the present invention provides a lithium-ion battery, including a housing and the parallel battery pack according to any one of the above, and the parallel battery pack is arranged inside the housing.

[0032] According to another aspect of the present invention, the present invention provides an assembly method for a parallel battery pack. The parallel battery pack is formed by using the assembly method for a parallel battery pack. The assembly method for a parallel battery pack includes: Step S10: Prepare a plurality of cylindrical battery cells and current collector members; Step S20: Arrange two of the plurality of cylindrical battery cells side by side; Step S30: Use the current collector member to connect the two side-by-side cylindrical battery cells in parallel, wherein the positive current collector plate is connected to the positive electrode tab regions of the two side-by-side cylindrical battery cells, and the negative current collector plate is connected to the negative electrode tab regions of the two side-by-side cylindrical battery cells; Step S40: Bend the current collector member, and stack one of the two side-by-side cylindrical battery cells on the other of the two side-by-side cylindrical battery cells; Step S50: Arrange another one of the plurality of cylindrical battery cells side by side with one of the two stacked cylindrical battery cells in Step S40; Step S60: Repeat Step S30 to Step S50 to parallelly connect and stack the plurality of cylindrical battery cells.

[0033] In the above technical solution, the positive current collector plate is used to connect the positive tab areas of two adjacent cylindrical battery cells, and the negative current collector plate is used to connect the negative tab areas of two adjacent cylindrical battery cells, so as to realize the parallel connection of multiple cylindrical battery cells. By bending the positive current collector plate and the negative current collector plate, the stacking of multiple cylindrical battery cells can be realized, so that multiple cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cell. In this way, on the one hand, compared with the traditional cylindrical battery PACK that requires multiple structural components to assemble a single battery cell, the present invention can reduce the number of structural components required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density. On the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not require a customized housing with a specific shape. Only by using a traditional cylindrical housing can multiple cylindrical battery cells be accommodated, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable.

[0034] Applying the technical solution of the present invention, the positive current collector plate is used to connect the positive tab areas of two adjacent cylindrical battery cells, and the negative current collector plate is used to connect the negative tab areas of two adjacent cylindrical battery cells, so as to realize the parallel connection of multiple cylindrical battery cells. By bending the positive current collector plate and the negative current collector plate, the stacking of multiple cylindrical battery cells can be realized, so that multiple cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cell. In this way, on the one hand, compared with the traditional cylindrical battery PACK that requires multiple structural components to assemble a single battery cell, the present invention can reduce the number of structural components required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density. On the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not require a customized housing with a specific shape. Only by using a traditional cylindrical housing can multiple cylindrical battery cells be accommodated, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The schematic diagrams in the specification that form a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 Fig. shows a schematic structural diagram of a first stacked unit of Embodiment 1 of the parallel battery pack of the present invention;

[0037] Figure 2 Fig. shows a schematic structural diagram of a first type of battery cell of Embodiment 1 of the parallel battery pack of the present invention;

[0038] Figure 3 Fig. shows Figure 2Schematic diagram of the structure of the first type of battery cell in another direction;

[0039] Figure 4 Shows Figure 2 A - A sectional view of the first type of battery cell;

[0040] Figure 5 Schematic diagram of the structure of the second laminated unit of the first embodiment of the parallel battery pack of the present invention;

[0041] Figure 6 Schematic diagram of the structure of the second type of battery cell of the first embodiment of the parallel battery pack of the present invention;

[0042] Figure 7 Shows Figure 6 Schematic diagram of the structure of the second type of battery cell in another direction;

[0043] Figure 8 Schematic diagram of the structure of the third laminated unit of the first embodiment of the parallel battery pack of the present invention;

[0044] Figure 9 Schematic diagram of the structure of the third type of battery cell of the first embodiment of the parallel battery pack of the present invention;

[0045] Figure 10 Shows Figure 9 Schematic diagram of the structure of the third type of battery cell in another direction;

[0046] Figure 11 Schematic diagram of the structure of the first type of battery cell and the second type of battery cell in parallel pairing in one direction of the first embodiment of the parallel battery pack of the present invention;

[0047] Figure 12 Shows Figure 11 Schematic diagram of the structure of the first type of battery cell and the second type of battery cell in parallel pairing in another direction;

[0048] Figure 13 Shows Figure 11 Schematic diagram of the structure of the first type of battery cell and the second type of battery cell connected by a positive current collector plate;

[0049] Figure 14 Shows Figure 11 Schematic diagram of the structure of the first type of battery cell and the second type of battery cell connected by a positive current collector plate and a negative current collector plate;

[0050] Figure 15 Schematic diagram of the structure of the current collector member of the first embodiment of the parallel battery pack of the present invention;

[0051] Figure 16 Schematic diagram of the structure of the first embodiment of the parallel battery pack of the present invention;

[0052] Figure 17 shows a partial cross-sectional view of a parallel battery pack; Figure 16 of;

[0053] Figure 18 shows another schematic structural view of Embodiment 1 of the parallel battery pack of the present invention;

[0054] Figure 19 shows Figure 18 a partial enlarged view of a parallel battery pack of;

[0055] Figure 20 shows a schematic structural view in one direction of the parallel pairing of the first type of battery cells, the second type of battery cells, and the third type of battery cells in Embodiment 1 of the parallel battery pack of the present invention;

[0056] Figure 21 shows Figure 20 a schematic structural view in another direction of the parallel pairing of the first type of battery cells, the second type of battery cells, and the third type of battery cells in a parallel battery pack of;

[0057] Figure 22 shows Figure 20 a schematic structural view of the connection of the second type of battery cells and the third type of battery cells in a parallel battery pack of through a current collecting member;

[0058] Figure 23 shows a schematic structural view of Embodiment 1 of the parallel battery pack of the present invention;

[0059] Figure 24 shows a schematic structural view of Embodiment 2 of the parallel battery pack of the present invention;

[0060] Figure 25 shows Figure 24 a schematic structural view of the current collecting member of a parallel battery pack of.

[0061] Among them, the above-mentioned drawings include the following reference numerals:

[0062] 10, positive electrode tab; 20, negative electrode tab; 101, positive electrode ear area; 102, positive electrode connection area; 201, negative electrode ear area; 202, negative electrode connection area; 30, separator; 40, first type of battery cell; 401, cell body; 402, cell through hole; 403, non-polar ear area; 404, external non-polar ear area; 50, positive current collecting plate; 501, positive through hole; 502, positive stress hole; 503, positive bending hole; 60, negative current collecting plate; 601, negative stress hole; 602, negative bending hole; 70, insulating member; 80, second type of battery cell; 90, third type of battery cell. Detailed implementation manners

[0063] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0064] Embodiment 1

[0065] As Figures 1 to 23 shown, Embodiment 1 of the present invention provides a parallel battery pack. The parallel battery pack includes: a plurality of cylindrical battery cells arranged in sequence along the axis of the cylindrical battery cells. The adjacent ends of two adjacent cylindrical battery cells each have a positive tab area 101 and a negative tab area 201; a current collector member located between two adjacent cylindrical battery cells. The current collector member includes a positive current collector plate 50 and a negative current collector plate 60. The positive current collector plate 50 is used to connect the positive tab areas 101 of two adjacent cylindrical battery cells, and the negative current collector plate 60 is used to connect the negative tab areas 201 of two adjacent cylindrical battery cells, so that two adjacent cylindrical battery cells are arranged in parallel. Among them, the positive current collector plate 50 and the negative current collector plate 60 are both bendably arranged, and one of the two adjacent cylindrical battery cells is stacked on the other of the two adjacent cylindrical battery cells.

[0066] In the above technical solution, by using the positive current collector plate 50 to connect the positive tab areas 101 of two adjacent cylindrical battery cells and using the negative current collector plate 60 to connect the negative tab areas 201 of two adjacent cylindrical battery cells, parallel connection of a plurality of cylindrical battery cells can be achieved. By bending the positive current collector plate 50 and the negative current collector plate 60, stacking of a plurality of cylindrical battery cells can be achieved, so that a plurality of cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cells. In this way, on the one hand, compared with the traditional cylindrical battery PACK package that requires multiple structural parts to assemble a single battery cell, the present invention can reduce the number of structural parts required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density; on the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not require a custom-made housing with a specific shape. Only a traditional cylindrical housing is needed to accommodate a plurality of cylindrical battery cells, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable.

[0067] As Figures 2 to 4 and Figure 13 shown, in Embodiment 1 of the present invention, the cylindrical battery cell includes a battery cell body 401. The battery cell body 401 has a battery cell through hole 402 extending along its own axial direction. The positive tab area 101 is arranged on the battery cell body 401 and is located on the periphery of the battery cell through hole 402. The positive current collector plate 50 is provided with two positive welding areas, and the two positive welding areas are respectively welded to the adjacent positive tab areas 101. Each positive welding area is provided with a positive through hole 501, and the two positive through holes 501 are correspondingly communicated with the adjacent battery cell through holes 402.

[0068] In the above technical solution, two positive welding areas on the positive current collector plate 50 are welded to two adjacent positive tab areas 101, realizing the parallel connection of two adjacent cylindrical battery cells. Moreover, through the communication between the positive through holes 501 and the cell through holes 402, the electrolyte is allowed to better infiltrate into the interiors of two adjacent cell bodies 401, thereby ensuring the uniform progress of the electrochemical reaction during the charging and discharging processes of the battery and improving the performance and lifespan of the battery.

[0069] As Figure 15 shown, in Embodiment 1 of the present invention, the positive current collector plate 50 has a positive bending portion located between two positive welding areas. The positive bending portion has a positive bending line, and the positive current collector plate 50 can be bent along the positive bending line. The line connecting the centers of two positive through holes 501 is arranged at an angle to the positive bending line.

[0070] In the above technical solution, by bending the positive current collector plate 50, one end of the cell body 401 can be stacked on one end of another cell body 401, enabling two adjacent cylindrical battery cells to be stacked, thereby arranging multiple cylindrical battery cells more closely, effectively utilizing the space inside the battery pack, and increasing the energy density. Moreover, an angle is formed between the line connecting the centers of two positive through holes 501 and the positive bending line, which can prevent bending to the positive through holes 501, ensuring that the cell through holes 402 can still maintain good electrical connection after bending, avoiding poor connection or breakage caused by bending, and improving the reliability of the battery pack.

[0071] As Figure 15 shown, in Embodiment 1 of the present invention, the positive current collector plate 50 is arranged symmetrically about the positive bending line.

[0072] In the above technical solution, for the symmetrically positive current collector plate 50 about the positive bending line, after the positive current collector plate 50 is bent, it can ensure that two positive through holes 501 can be aligned, so that two cell through holes 402 can be communicated through two positive through holes 501 to ensure the electrical connection path between two adjacent cylindrical battery cells, thereby ensuring that all battery cells have the same electrical performance during parallel connection and improving the overall consistency of the battery pack.

[0073] As Figure 15 shown, in Embodiment 1 of the present invention, the positive bending portion includes a plurality of positive bending holes 503 arranged in sequence, and the line connecting the centers of the plurality of positive bending holes 503 forms the positive bending line.

[0074] In the above technical solution, the setting of the plurality of positive bending holes 503 makes it easier for the positive current collector plate 50 to be bent along the line connecting the centers of these holes, ensuring both the accuracy of bending and simplifying the bending operation process, and improving the assembly efficiency of the battery pack.

[0075] Furthermore, in the first embodiment of the present invention, the provision of the positive bending holes 503 reduces the material usage of the positive current collector plate 50, thereby reducing the weight of a single battery and the battery pack. This is particularly important for weight-sensitive applications such as mobile devices or electric vehicles, and contributes to the lightweight design of the overall device.

[0076] As Figures 2 to 4 and Figure 14 shown, in the first embodiment of the present invention, the negative tab area 201 is disposed on the cell body 401 and is located on the outer peripheral side of the positive tab area 101. Along the radial direction of the cell body 401, the positive tab area 101 and the negative tab area 201 are spaced apart to form an external tabless area 404. The negative current collector plate 60 is located on the outer periphery of the positive current collector plate 50, and there is a gap between the negative current collector plate 60 and the positive current collector plate 50. The negative current collector plate 60 is provided with two negative welding areas, and the two negative welding areas are respectively welded to the negative tab areas 201 of two adjacent cylindrical cells.

[0077] In the above technical solution, on the one hand, the positive tab area 101 and the negative tab area 201 are spaced apart, and the external tabless area 404 formed therebetween effectively prevents direct contact between the positive and negative tabs, avoids the risk of internal short circuit, and significantly improves the safety of the battery pack. On the other hand, a gap is maintained between the positive current collector plate 50 and the negative current collector plate 60, which not only achieves electrical isolation but also ensures the insulation performance between the positive and negative poles, enhancing the electrical safety of the battery pack. On the further hand, by providing two negative welding areas on the negative current collector plate 60, the negative tab areas 201 of two adjacent cells can be welded simultaneously, achieving the efficiency of parallel connection, simplifying the electrical assembly process of the battery pack, and improving the production efficiency.

[0078] As Figure 15 shown, in the first embodiment of the present invention, the negative current collector plate 60 has a negative bending portion located between the two negative welding areas. The negative bending portion has a negative bending line, and the negative current collector plate 60 can be bent along the negative bending line. The line connecting the centers of the two cylindrical cells forms an angle with the negative bending line.

[0079] In the above technical solution, by bending the negative current collector plate 60, one end of the cell body 401 can be stacked on one end of another cell body 401, enabling adjacent two cylindrical cells to be stacked, thereby arranging multiple cylindrical cells more closely, effectively utilizing the space within the battery pack, and increasing the energy density.

[0080] As Figure 15 shown, in the first embodiment of the present invention, the negative current collector plate 60 is arranged symmetrically about the negative bending line.

[0081] In the above technical solution, the mirror-symmetric design helps to ensure uniform stress distribution on both sides of the current collector plate during the bending process, avoiding material deformation or fracture that may be caused by unilateral stress concentration, and improving the structural stability and reliability of the negative current collector plate 60; and the symmetric setting ensures that the electrical connection paths and resistances between all the negative tab areas 201 and the negative current collector plate 60 are consistent, which helps to improve the overall electrical performance consistency of the battery pack and avoid performance fluctuations caused by connection differences.

[0082] Furthermore, in Embodiment 1 of the present invention, for the mirror-symmetric negative current collector plate 60, after the negative current collector plate 60 is bent, it can ensure that the two positive through holes 501 can be aligned, so that the two cell through holes 402 can be connected through the two positive through holes 501 to ensure the electrical connection path between adjacent two cylindrical cells, thereby ensuring that all cells have the same electrical performance when connected in parallel and improving the overall consistency of the battery pack.

[0083] As Figure 15 shown, in Embodiment 1 of the present invention, the negative bending part includes a plurality of negative bending holes 602 arranged in sequence, and the connection line of the centers of the plurality of negative bending holes 602 forms a negative bending line.

[0084] In the above technical solution, the setting of the plurality of negative bending holes 602 makes it easier for the negative current collector plate 60 to be bent along the connection line of the centers of these holes, which not only ensures the accuracy of bending but also simplifies the bending operation process and improves the assembly efficiency of the battery pack.

[0085] Furthermore, in Embodiment 1 of the present invention, the setting of the negative bending holes 602 reduces the material usage of the negative current collector plate 60, thereby reducing the weight of a single battery and the battery pack, which is particularly important for weight-sensitive applications such as mobile devices or electric vehicles and helps with the lightweight design of the overall device.

[0086] As Figure 15 shown, in Embodiment 1 of the present invention, at least one negative stress hole 601 is provided on the negative current collector plate 60; and / or, at least one positive stress hole 502 is provided on the positive current collector plate 50.

[0087] In the above technical solution, the setting of stress holes on the current collector plate can effectively release the thermal stress and mechanical stress generated during the welding process, avoid deformation or cracks caused by stress concentration, and enhance the structural stability and reliability of the current collector plate; and the design of the stress holes can reduce the material usage of the current collector plate, thereby reducing the weight of the battery pack, which is particularly important for applications such as portable devices or electric vehicles that pursue lightweight design.

[0088] As Figures 21 to 23As shown in the figure, in the first embodiment of the present invention, along the arrangement direction of a plurality of cylindrical battery cells, one end of the first cylindrical battery cell among the plurality of cylindrical battery cells has a positive electrode tab area 101 and a negative electrode tab area 201, and the other end of the first cylindrical battery cell among the plurality of cylindrical battery cells has a negative electrode connection area 202; along the arrangement direction of the plurality of cylindrical battery cells, one end of the last cylindrical battery cell among the plurality of cylindrical battery cells has a positive electrode tab area 101 and a negative electrode tab area 201, and the other end of the last cylindrical battery cell among the plurality of cylindrical battery cells has a positive electrode connection area 102; both ends of the remaining cylindrical battery cells among the plurality of cylindrical battery cells are provided with a positive electrode tab area 101 and a negative electrode tab area 201.

[0089] Through the above settings, the negative electrode connection area 202 and the positive electrode connection area 102 can be directly externally electrically connected, simplifying the construction of the parallel circuit of the battery pack and improving the efficiency and reliability of the electrical connection; and both ends of the intermediate battery cells are provided with positive and negative electrode tab areas, enabling the battery cells to be closely arranged, reducing the gaps between the battery cells, improving the space utilization rate of the battery pack, and thus increasing the overall energy density of the battery pack.

[0090] As Figures 1 to 4 shown, in the first embodiment of the present invention, the plurality of cylindrical battery cells include a first type of battery cell 40 wound from a first laminated unit. Along the length direction of the first laminated unit, the first laminated unit is divided into a first area S1, a second area S2, a third area S3, and a fourth area S4 arranged in sequence. Along the width direction of the first laminated unit, the first laminated unit has a first side and a second side arranged opposite to each other; a positive electrode tab is provided on the first side of the second area S2 to form a positive electrode tab area 101; a negative electrode tab is provided on the first side of the fourth area S4 to form a negative electrode tab area 201; a positive electrode tab is provided on the second side of at least one of the second area S2, the third area S3, and the fourth area S4 to form a positive electrode connection area 102.

[0091] In the above technical solution, by providing a positive electrode tab on the first side of the second area S2 to form a positive electrode tab area 101, providing a negative electrode tab on the first side of the fourth area S2 to form a negative electrode tab area 201, and providing a positive electrode connection area 102 on the second side of the second area S2, the third area S3, and the fourth area S4, parallel connection with other cylindrical battery cells can be achieved, and the cylindrical battery cells can also be connected to an external power source or an external device to be powered.

[0092] It should be noted that in the first embodiment of the present invention, as Figure 1 shown, the first laminated unit is wound along its own length direction, the width direction is the direction perpendicular to the paper surface, and the width direction of the first laminated unit is the same as the axis direction of the second type of battery cell.

[0093] As Figures 5 to 7As shown in the figure, in the first embodiment of the present invention, multiple cylindrical battery cells include a second type of battery cell 80 wound from a second stacked unit. Along the length direction of the second stacked unit, the second stacked unit is divided into a first region S1, a second region S2, a third region S3, and a fourth region S4 arranged in sequence. Along the width direction of the second stacked unit, the second stacked unit has a first side and a second side arranged opposite to each other; both the first side and the second side of the second region S2 are provided with positive electrode tabs, so as to form positive electrode tab regions 101 on both the first side and the second side, and both the first side and the second side of the fourth region S4 are provided with negative electrode tabs, so as to form negative electrode tab regions 201 on both the first side and the second side.

[0094] In the above technical solution, the positive and negative electrode tabs are respectively distributed on both sides of the battery cell, which can simplify the welding process of the current collector plate, avoid the problems of occlusion or difficulty in reaching that may be encountered during single-sided welding, improve the welding quality and production efficiency; and the double-sided electrode tab design allows the battery cells to be arranged and connected in various ways, improves the flexibility of parallel connection of the battery cells, helps to optimize the layout of the battery cells inside the battery pack, and realizes a higher energy density.

[0095] It should be noted that in the first embodiment of the present invention, as Figure 5 shown, the second stacked unit is wound along its own length direction, the width direction is the direction perpendicular to the paper surface, and the width direction of the second stacked unit is the same as the axis direction of the second type of battery cell.

[0096] As Figures 8 to 10 shown, in the first embodiment of the present invention, multiple cylindrical battery cells include a third type of battery cell 90 wound from a third stacked unit. Along the length direction of the third stacked unit, the third stacked unit is divided into a first region S1, a second region S2, a third region S3, and a fourth region S4 arranged in sequence. Along the width direction of the third stacked unit, the third stacked unit has a first side and a second side arranged opposite to each other; the first side of the second region S2 is provided with a positive electrode tab to form a positive electrode tab region 101; the first side of the fourth region S4 is provided with a negative electrode tab to form a negative electrode tab region 201; at least one of the second regions S2, S3, and S4 is provided with a negative electrode tab on the second side to form a negative connection region 202.

[0097] In the above technical solution, by providing a positive electrode tab on the first side of the second region S2 to form a positive electrode tab region 101, providing a negative electrode tab on the first side of the fourth region S2 to form a negative electrode tab region 201, and providing a negative connection region 202 on the second side of the second region S2, the third region S3, and the fourth region S4, parallel connection with other cylindrical battery cells can be realized, and the cylindrical battery cell can also be connected to an external power supply or an external device to be powered.

[0098] It should be noted that in the first embodiment of the present invention, as Figure 8As shown, the third stacked layer unit is wound along its own length direction, the width direction is the direction perpendicular to the paper surface, and the width direction of the third stacked layer unit is the same as the axis of the third type of battery cell.

[0099] Figure 1 is a schematic diagram of the electrode sheet of the first type of battery cell 40 in the first embodiment of the present invention. From bottom to top, it is a four-layer unit (the first stacked layer unit) formed by a separator 30, a negative electrode sheet 20, a separator 30, and a positive electrode sheet 10. The above four-layer unit is divided into four regions, where S1 corresponds to the internal earless region 403, S2 corresponds to the positive electrode ear region 101, S3 corresponds to the external earless region 404, and S4 corresponds to the negative electrode ear region 201. Among them, the positive electrode sheet 10 is formed by coating a positive electrode active material on an aluminum foil and then drying and rolling. The positive electrode ear is formed by cutting the aluminum foil that has not been coated with the positive electrode active material. The positive electrode ear is located on the upper side (the first side) and the lower side (the second side) of the positive electrode sheet 10, and the positive electrode ear located on the upper side only exists in the S2 region, and the positive electrode ear located on the lower side exists in the S2, S3, and S4 regions. The negative electrode sheet 20 is formed by coating a negative electrode active material on a copper foil and then drying and rolling. The negative electrode ear is formed by cutting the copper foil that has not been coated with the negative electrode active material. The negative electrode ear is located on the upper side (the first side) of the negative electrode sheet 20, and the negative electrode ear only exists in the S4 region. A plurality of continuously arranged negative electrode ears form an ear cluster M, and the ear clusters M are arranged at intervals.

[0100] Figure 2 and Figure 3 are schematic diagrams of the front and rear end faces of the first type of battery cell 40 in the first embodiment of the present invention. The above four-layer unit is wound clockwise from left to right to obtain the first type of battery cell 40. From the front end, it can be seen that both the positive electrode ear and the negative electrode ear are closely attached to the end face of the battery cell body 401. The center position of the battery cell body 401 is the battery cell through hole 402. The S1 region forms the internal earless region 403 after winding, the S2 region forms the positive electrode ear region 101 after winding, the S3 region forms the external earless region 404 after winding, and the S4 region forms the negative electrode ear region 201 after winding. Since the negative electrode ear clusters M in the S4 region are arranged at intervals, the negative electrode ear clusters M correspond to the negative electrode ear region 201, and the interval regions between the ear clusters M correspond to the earless regions; from the rear end, it can be seen that the positive electrode ear is closely attached to the end face of the battery cell body 401, and the S2, S3, and S4 regions form the positive electrode connection region 102 after winding.

[0101] Figure 4 Among them, the battery cell through hole 402 is formed by the winding needle during winding, which can facilitate the better immersion of the electrolyte into the battery cell; the internal earless region 403 is set to prevent the positive electrode ear region 101 from blocking the battery cell through hole 402; the external earless region 404 is set to prevent the positive electrode ear region 101 and the negative electrode ear region 201 from contacting each other and causing a short circuit of the battery cell.

[0102] Figure 5 It is a schematic diagram of the electrode sheet expansion of the second type of battery cell 80 in the first embodiment of the present invention. From bottom to top, there are four layers of units (second stacked units) formed by the separator 30, the negative electrode sheet 20, the separator 30, and the positive electrode sheet 10. The above four layers of units are divided into four regions. Among them, S1 corresponds to the internal earless region 403, S2 corresponds to the positive electrode ear region 101, S3 corresponds to the external earless region 404, and S4 corresponds to the negative electrode ear region 201. Among them, the positive electrode sheet 10 is formed by coating positive electrode active material on aluminum foil and then drying and rolling. The positive electrode ear is formed by cutting aluminum foil that has not been coated with positive electrode active material. The positive electrode ear is located on the upper side (first side) and the lower side (second side) of the positive electrode sheet 10, and at this time, the positive electrode ear only exists in the S2 region. The negative electrode sheet 20 is formed by coating negative electrode active material on copper foil and then drying and rolling. The negative electrode ear is formed by cutting copper foil that has not been coated with negative electrode active material. The negative electrode ear is located on the upper side (first side) and the lower side (second side) of the negative electrode sheet 20, and at this time, the negative electrode ear only exists in the S4 region. A plurality of continuously arranged negative electrode ears form an ear cluster M. The positions of the upper and lower ear clusters M correspond to each other, and the ear clusters M are arranged at intervals.

[0103] Figure 6 and Figure 7 They are schematic diagrams of the front and rear end faces of the second type of battery cell 80 in the first embodiment of the present invention. The above four layers of units are wound clockwise from left to right to obtain the second type of battery cell 80. From the front end, it can be seen that both the positive electrode ear and the negative electrode ear are closely attached to the end face of the battery cell body 401. The center position of the battery cell body 401 is the battery cell through hole 402. The S1 region forms the internal earless region 403 after winding, the S2 region forms the positive electrode ear region 101 after winding, the S3 region forms the external earless region 404 after winding, and the S4 region forms the negative electrode ear region 201 after winding. Since the negative electrode ear clusters M in the S4 region are arranged at intervals, the negative electrode ear clusters M correspond to the negative electrode ear region 201, and the interval regions between the ear clusters M correspond to the earless regions; from the rear end, it can be seen that both the positive electrode ear and the negative electrode ear are closely attached to the end face of the battery cell body 401. The S1 region forms the internal earless region 403 after winding, the S2 region forms the positive electrode ear region 101 after winding, the S3 region forms the external earless region 404 after winding, and the S4 region forms the negative electrode ear region 201 after winding. Since the negative electrode ear clusters M in the S4 region are arranged at intervals, the negative electrode ear clusters M correspond to the negative electrode ear region 201, and the interval regions between the ear clusters M correspond to the earless regions.

[0104] Figure 8It is a schematic diagram of the electrode sheet expansion of the third type of battery cell 90 in the first embodiment of the present invention. From bottom to top, there are four layers of units (the third stacked unit) formed by the separator 30, the negative electrode sheet 20, the separator 30, and the positive electrode sheet 10. The above four-layer unit is divided into four regions, where S1 corresponds to the internal tabless region 403, S2 corresponds to the positive tab region 101, S3 corresponds to the external tabless region 404, and S4 corresponds to the negative tab region 201. The positive electrode sheet 10 is formed by coating positive electrode active material on aluminum foil and then drying and rolling. The positive tab is formed by cutting aluminum foil without coating positive electrode active material. The positive tab is located on the upper side (the first side) of the positive electrode sheet 10, and at this time, the positive tab only exists in the S2 region. The negative electrode sheet 20 is formed by coating negative electrode active material on copper foil and then drying and rolling. The negative tab is formed by cutting copper foil without coating negative electrode active material. The negative tab is located on the upper side (the first side) and the lower side (the second side) of the negative electrode sheet 20. The negative tab on the upper side only exists in the S4 region, and a tab cluster M is formed by several continuously arranged negative tabs. The tab clusters M are arranged at intervals; the negative tab on the lower side exists in the S2, S3, and S4 regions.

[0105] Figure 9 and Figure 10 It is a schematic diagram of the front and rear end faces of the third type of battery cell 90 in the first embodiment of the present invention. The above four-layer unit is wound clockwise from left to right to obtain the third type of battery cell 90. As can be seen from the front end, both the positive tab and the negative tab are closely attached to the end face of the battery cell body 401. The center position of the battery cell body 401 is the battery cell through hole 402. The S1 region forms the internal tabless region 403 after winding, the S2 region forms the positive tab region 101 after winding, the S3 region forms the external tabless region 404 after winding, and the S4 region forms the negative tab region 201 after winding. Since the negative tab clusters M in the S4 region are arranged at intervals, the negative tab clusters M correspond to the negative tab region 201, and the interval regions between the tab clusters M correspond to the tabless regions; as can be seen from the rear end, the negative tab is closely attached to the end face of the battery cell body 401, and the S2, S3, and S4 regions form the negative connection region 202 after winding.

[0106] Figure 11 、 Figure 12 It is a schematic diagram of the end face when the first type of battery cell 40 and the second type of battery cell 80 in the first embodiment of the present invention are connected in parallel and paired. The first type of battery cell 40 and the second type of battery cell 80 are placed side by side, and their outer circles are tangent to each other. From the front end face, the positions of their tabs are in a mirror image state.

[0107] Figure 13It is a schematic diagram of installing the positive current collector plate 50 when the first type of battery cell 40 and the second type of battery cell 80 are connected in parallel and paired in the first embodiment of the present invention. The positive current collector plate 50 is a thin aluminum sheet, on which positive through holes 501, positive stress holes 502, and positive bending holes 503 are provided. The positive current collector plate 50 covers the entire positive tab area 101 of the first type of battery cell 40 and the second type of battery cell 80, and the positive through hole 501 is located directly above the cell through hole 402. The positive current collector plate 50 and the positive tab area 101 are welded together by laser. On the one hand, the positive stress hole 502 can release the stress generated during the welding process, and on the other hand, it can also reduce the weight of the positive current collector plate 50, thereby improving the energy density of the entire battery.

[0108] Figure 14 It is a schematic diagram of installing the negative current collector plate 60 when the first type of battery cell 40 and the second type of battery cell 80 are connected in parallel and paired in the first embodiment of the present invention. On the Figure 13 basis, the negative current collector plate 60 is installed. The negative current collector plate 60 is a thin copper sheet, on which negative stress holes 601 and negative bending holes 602 are provided. The negative current collector plate 60 covers the entire negative tab area 201 of the first type of battery cell 40 and the second type of battery cell 80. The negative current collector plate 60 and the negative tab area 201 are welded together by laser. On the one hand, the negative stress hole 601 can release the stress generated during the welding process, and on the other hand, it can also reduce the weight of the negative current collector plate 60, thereby improving the energy density of the entire battery.

[0109] Figure 15 It is a schematic diagram of the structures of the positive current collector plate 50 and the negative current collector plate 60 in the first embodiment of the present invention. Both the positive current collector plate 50 and the negative current collector plate 60 have a left-right symmetric structure, and the symmetry center coincides with the centers of the positive bending hole 503 and the negative bending hole 602.

[0110] Figure 16 、 Figure 17 It is a schematic diagram of the state after bending the two current collector plates simultaneously in the first embodiment of the present invention. On the Figure 14 basis, the positive current collector plate 50 and the negative current collector plate 60 are respectively bent 180 degrees along the above symmetry center. At this time, the centers of the two positive through holes 501 coincide with the center of the cell through hole 402. The bent part of the negative current collector plate 60 after bending extends outside the cylindrical cell body 401.

[0111] Figure 18 、 Figure 19 It is a schematic diagram of the structure of folding the negative current collector plate towards the cell body after the two battery cells are connected in parallel in the first embodiment of the present invention. On the Figure 16 basis, the bent part of the negative current collector plate that extends outside the cell body 401 is folded towards the outer surface of the cell body 401. The purpose is to facilitate the subsequent operation of inserting the parallel-connected battery cells into the case.

[0112] Figure 20, Figure 21 It is a front-end view of the third type of battery cell 90 in parallel pairing with the first type of battery cell 40 and the second type of battery cell 80 in the first embodiment of the present invention. On the basis of Figure 18 , the third type of battery cell 90 and the second type of battery cell 80 are placed side by side, and their outer circles are tangent to each other. From the front-end view, the positions of their tabs are in a mirror image state.

[0113] Figure 22 It is a schematic structural view of installing current collectors on the second type of battery cell 80 and the third type of battery cell 90 in the first embodiment of the present invention. The above-mentioned positive current collector 50 and negative current collector 60 are respectively welded on the positive tab area 101 and negative tab area 201.

[0114] Figure 23 It is a schematic structural view of folding the negative current collector towards the battery cell body after the third battery cells are connected in parallel in the first embodiment of the present invention. On the basis of Figure 22 , the bent part of the negative electrode extending outside the battery cell body 401 is folded towards the outer surface of the battery cell body 401.

[0115] The first embodiment of the present invention gives an example of the state when three battery cells are connected in parallel, but the present invention is applicable to the case where the number of battery cells connected in parallel ≥ 2. When the number of battery cells connected in parallel is K (K is an integer ≥ 2), the number of the first type of battery cell 40 and the third type of battery cell 90 is 1 each, and the number of the second type of battery cell 80 is M - 2. At this time, the first type of battery cell 40 and the third type of battery cell 90 are respectively located at both ends of the entire parallel battery pack. One end face of the entire parallel battery pack after parallel connection is the positive tab, and the other end face is the negative tab.

[0116] Compared with the traditional cylindrical battery that mostly uses single battery cell assembly, the present invention realizes the parallel assembly of any number of battery cells. The present invention also provides different structural forms of current collectors. Among them, the positive and negative current collectors in the second embodiment adopt an integrated structure design, which can more conveniently position the relative positions of the positive and negative current collectors and improve the qualification rate of subsequent bending of the current collectors. The present invention reduces the number of structural parts used in the cylindrical battery and can effectively improve the energy density of the cylindrical battery.

[0117] Embodiment Two

[0118] As Figure 24 and Figure 25 shown, the difference between the second embodiment of the present invention and the first embodiment is that the parallel battery pack further includes at least one insulating member 70 located between the positive current collector 50 and the negative current collector 60. The insulating member 70 is correspondingly arranged with the external tabless area 404. One end of the insulating member 70 is connected to the positive current collector 50, and the other end of the insulating member 70 is connected to the negative current collector 60 to form an integrated current collector structure. Among them, the insulating member 70 is made of insulating material.

[0119] In the above technical solution, the insulating member 70 effectively isolates the positive current collector plate 50 and the negative current collector plate 60, avoiding direct contact between them, significantly improving the electrical safety of the battery pack, and preventing short - circuit phenomena caused by direct contact between the plates; moreover, the integrated current collector plate structure reduces the alignment difficulty of the positive and negative current collector plates during assembly, simplifies the steps of battery assembly, reduces the error rate and complexity in the manufacturing process of the battery pack, and improves production efficiency.

[0120] Furthermore, in Embodiment 2 of the present invention, the insulating member 70 not only plays the role of electrical isolation but also connects the positive and negative current collector plates as a structural component, enhancing the stability of the entire current collector plate structure, which helps to protect the connection between the battery cells and the current collector plate from damage when the battery pack is subjected to external impacts or vibrations.

[0121] Preferably, in Embodiment 2 of the present invention, the insulating member 70 is a spoke, and the spoke is made of a non - metallic insulating material.

[0122] The other structures of Embodiment 2 are the same as those of Embodiment 1 and will not be elaborated here.

[0123] An embodiment of the present invention provides a lithium - ion battery, including a housing and the above - mentioned parallel battery pack, and the parallel battery pack is disposed inside the housing.

[0124] The above lithium - ion battery has all the advantages of the above - mentioned parallel battery pack and will not be elaborated here.

[0125] As shown in the figure, an embodiment of the present invention provides an assembly method for a parallel battery pack. Using the assembly method for a parallel battery pack to form the above - mentioned parallel battery pack, the assembly method for a parallel battery pack includes: Step S10: Prepare a plurality of cylindrical battery cells and current collector members; Step S20: Arrange two of the plurality of cylindrical battery cells side by side; Step S30: Use the current collector member to connect the two side - by - side cylindrical battery cells in parallel, where the positive current collector plate 50 is connected to the positive ear regions 101 of the two side - by - side cylindrical battery cells, and the negative current collector plate 60 is connected to the negative ear regions 201 of the two side - by - side cylindrical battery cells; Step S40: Bend the current collector member and stack one of the two side - by - side cylindrical battery cells on the other of the two side - by - side cylindrical battery cells; Step S50: Arrange another one of the plurality of cylindrical battery cells side by side with one of the two stacked cylindrical battery cells in Step S40; Step S60: Repeat Steps S30 to S50 to connect and stack the plurality of cylindrical battery cells in parallel.

[0126] In the above technical solution, the positive current collector plate 50 is used to connect the positive tab areas 101 of two adjacent cylindrical battery cells, and the negative current collector plate 60 is used to connect the negative tab areas 201 of two adjacent cylindrical battery cells, so that parallel connection of multiple cylindrical battery cells can be achieved. By bending the positive current collector plate 50 and the negative current collector plate 60, stacking of multiple cylindrical battery cells can be realized, so that multiple cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cell. In this way, on the one hand, compared with the traditional cylindrical battery PACK that requires multiple structural parts to assemble a single battery cell, the present invention can reduce the number of structural parts required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density; on the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not require a customized housing with a specific shape, and only a traditional cylindrical housing is needed to accommodate multiple cylindrical battery cells, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable.

[0127] The assembly method of the above parallel-connected battery pack has all the advantages of the above parallel-connected battery pack, which will not be elaborated here.

[0128] It should be noted that in the present invention, different types of cylindrical battery cells are combined in structure. First, the positive current collector plate 50 and the negative current collector plate 60 are respectively welded to the positive and negative tabs of two corresponding cylindrical battery cells, and then the position stacking is realized by bending the positive and negative current collector plates. Finally, the same operation is performed by adding different numbers of cylindrical battery cells to achieve parallel assembly of any number of cylindrical battery cells.

[0129] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: by connecting the positive tab areas of two adjacent cylindrical battery cells through the positive current collector plate and connecting the negative tab areas of two adjacent cylindrical battery cells through the negative current collector plate, parallel connection of multiple cylindrical battery cells can be achieved. By bending the positive current collector plate and the negative current collector plate, stacking of multiple cylindrical battery cells can be realized, so that multiple cylindrical battery cells can be arranged in sequence along the axis of the cylindrical battery cell. In this way, on the one hand, compared with the traditional cylindrical battery PACK that requires multiple structural parts to assemble a single battery cell, the present invention can reduce the number of structural parts required for the lithium-ion battery pack, thereby reducing the weight of the lithium-ion battery pack and improving the overall energy density; on the other hand, compared with the traditional solution that uses a housing with a specific shape to accommodate the parallel-connected battery cells, the present invention does not require a customized housing with a specific shape, and only a traditional cylindrical housing is needed to accommodate multiple cylindrical battery cells, thereby simplifying the manufacturing process of the lithium-ion battery pack, reducing the customization cost, and making the entire manufacturing process simpler and more reliable.

[0130] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A parallel battery pack, characterized in that: include: A plurality of cylindrical battery cells are arranged in sequence along the axis of the cylindrical battery cells, and adjacent ends of two adjacent cylindrical battery cells each have a positive electrode ear region (101) and a negative electrode ear region (201); A current collecting component is located between two adjacent cylindrical battery cells, and the current collecting component includes a positive current collecting disk (50) and a negative current collecting disk (60). The positive current collecting disk (50) is used to connect the positive ear areas (101) of the two adjacent cylindrical battery cells, and the negative current collecting disk (60) is used to connect the negative ear areas (201) of the two adjacent cylindrical battery cells, so that the two adjacent cylindrical battery cells are arranged in parallel, wherein the positive current collecting disk (50) and the negative current collecting disk (60) can both be arranged in a bendable manner, and one of the two adjacent cylindrical battery cells is stacked on the other of the two adjacent cylindrical battery cells.

2. The parallel battery pack according to claim 1, characterized in that: The cylindrical battery cell comprises a battery cell body (401), the battery cell body (401) having a battery cell through hole (402) extending along its own axial direction, the positive electrode ear area (101) is arranged on the battery cell body (401) and is located on the peripheral side of the battery cell through hole (402), the positive electrode current collecting disk (50) is provided with two positive welding areas, the two positive welding areas are respectively welded to two adjacent positive electrode ear areas (101), each of the positive welding areas is provided with a positive electrode through hole (501), and the two positive electrode through holes (501) are correspondingly connected to two adjacent battery cell through holes (402).

3. The parallel battery pack according to claim 2, characterized in that: The positive current collector disk (50) has a positive bending portion, the positive bending portion is located between the two positive welding areas, the positive bending portion has a positive bending line, the positive current collector disk (50) can be bent along the positive bending line, and a line passing through the centers of the two positive through holes (501) is arranged at an angle to the positive bending line.

4. The parallel battery pack according to claim 3, characterized in that: The positive electrode current collecting disk (50) is arranged in mirror symmetry with respect to the positive electrode bending line; and / or the positive electrode bending portion comprises a plurality of positive electrode bending holes (503) arranged in sequence, and a line connecting the centers of the plurality of positive electrode bending holes (503) forms the positive electrode bending line.

5. The parallel battery pack according to claim 2, characterized in that: The negative electrode ear region (201) is arranged on the battery cell body (401) and is located on the outer peripheral side of the positive electrode ear region (101). Along the radial direction of the battery cell body (401), the positive electrode ear region (101) and the negative electrode ear region (201) are spaced apart to form an external non-electrode ear region (404). The negative electrode current collecting disk (60) is located on the outer periphery of the positive electrode current collecting disk (50). There is a space between the negative electrode current collecting disk (60) and the positive electrode current collecting disk (50). The negative electrode current collecting disk (60) is provided with two negative welding regions, and the two negative welding regions are respectively welded to the negative electrode ear regions (201) of two adjacent cylindrical battery cells.

6. The parallel battery pack according to claim 5, characterized in that: The negative electrode current collector (60) has a negative electrode bending portion, the negative electrode bending portion is located between the two negative welding areas, the negative electrode bending portion has a negative electrode bending line, the negative electrode current collector (60) can be bent along the negative electrode bending line, and a line passing through the centers of the two cylindrical battery cells is arranged at an angle to the negative electrode bending line.

7. The parallel battery pack according to claim 6, characterized in that: The negative electrode current collecting plate (60) is arranged in mirror symmetry with respect to the negative electrode bending line; and / or the negative electrode bending portion comprises a plurality of negative electrode bending holes (602) arranged in sequence, and a line connecting the centers of the plurality of negative electrode bending holes (602) forms the negative electrode bending line.

8. The parallel battery pack according to claim 5, characterized in that: The parallel battery pack also includes at least one insulating component (70) located between the positive current collector disk (50) and the negative current collector disk (60), wherein the insulating component (70) is arranged corresponding to the external non-polar lug area (404), one end of the insulating component (70) is connected to the positive current collector disk (50), and the other end of the insulating component (70) is connected to the negative current collector disk (60) to form an integrated current collector disk structure, wherein the insulating component (70) is made of an insulating material.

9. The parallel battery pack according to any one of claims 1 to 8, characterized in that: The negative electrode current collecting disc (60) is provided with at least one negative electrode stress hole (601); and / or the positive electrode current collecting disc (50) is provided with at least one positive electrode stress hole (502).

10. The parallel battery pack according to any one of claims 1 to 8, characterized in that: Along the arrangement direction of the plurality of cylindrical battery cells, one end of the first cylindrical battery cell among the plurality of cylindrical battery cells has the positive electrode ear region (101) and the negative electrode ear region (201), and the other end of the first cylindrical battery cell among the plurality of cylindrical battery cells has a negative electrode connection region (202); Along the arrangement direction of the plurality of cylindrical battery cells, one end of the last cylindrical battery cell among the plurality of cylindrical battery cells has the positive electrode ear region (101) and the negative electrode ear region (201), and the other end of the last cylindrical battery cell among the plurality of cylindrical battery cells has a positive electrode connection region (102); The two ends of the remaining cylindrical battery cells among the plurality of cylindrical battery cells are both provided with the positive electrode lug area (101) and the negative electrode lug area (201).

11. The parallel battery pack according to claim 10, characterized in that: The plurality of cylindrical battery cells include a first type of battery cell (40) formed by winding a first laminate unit, wherein along the length direction of the first laminate unit, the first laminate unit is divided into a first region (S1), a second region (S2), a third region (S3) and a fourth region (S4) arranged in sequence, and along the width direction of the first laminate unit, the first laminate unit has a first side and a second side arranged oppositely; A positive electrode ear is provided on the first side of the second region (S2) to form the positive electrode ear area (101); a negative electrode ear is provided on the first side of the fourth region (S4) to form the negative electrode ear area (201); and a positive electrode ear is provided on the second side of at least one of the second region (S2), the third region (S3) and the fourth region (S4) to form the positive electrode connection area (102).

12. The parallel battery pack according to claim 10, characterized in that: The plurality of cylindrical battery cells include a second type of battery cell (80) formed by winding a second laminate unit, wherein along the length direction of the second laminate unit, the second laminate unit is divided into a first region (S1), a second region (S2), a third region (S3) and a fourth region (S4) arranged in sequence, and along the width direction of the second laminate unit, the second laminate unit has a first side and a second side arranged oppositely; The first side and the second side of the second region (S2) are both provided with positive electrode ears to form the positive electrode ear area (101) on the first side and the second side, and the first side and the second side of the fourth region (S4) are both provided with negative electrode ears to form the negative electrode ear area (201) on the first side and the second side.

13. The parallel battery pack according to claim 10, characterized in that: The plurality of cylindrical battery cells include a third type of battery cell (90) formed by winding a third laminate unit, wherein along the length direction of the third laminate unit, the third laminate unit is divided into a first region (S1), a second region (S2), a third region (S3) and a fourth region (S4) arranged in sequence, and along the width direction of the third laminate unit, the third laminate unit has a first side and a second side arranged oppositely; A positive electrode ear is provided on the first side of the second region (S2) to form the positive electrode ear region (101); a negative electrode ear is provided on the first side of the fourth region (S4) to form the negative electrode ear region (201); and a negative electrode ear is provided on the second side of at least one of the second region (S2), the third region (S3) and the fourth region (S4) to form the negative electrode connection region (202).

14. A lithium ion battery, characterized in that: The invention comprises a housing and the parallel battery pack according to any one of claims 1 to 13, wherein the parallel battery pack is arranged in the housing.

15. A method for assembling a parallel battery pack, characterized in that: The parallel battery pack according to any one of claims 1 to 13 is formed by using a parallel battery pack assembly method, the parallel battery pack assembly method comprising: Step S10: preparing a plurality of the cylindrical battery cells and the current collecting components; Step S20: arranging two of the cylindrical battery cells in parallel among the plurality of cylindrical battery cells; Step S30: using the current collecting component to connect the two cylindrical battery cells arranged in parallel in parallel, wherein the positive current collecting plate (50) is connected to the positive electrode ear regions (101) of the two cylindrical battery cells arranged in parallel, and the negative current collecting plate (60) is connected to the negative electrode ear regions (201) of the two cylindrical battery cells arranged in parallel; Step S40: bending the current collecting member, and stacking one of the two cylindrical battery cells arranged in parallel on the other of the two cylindrical battery cells arranged in parallel; Step S50: placing another cylindrical battery cell among the plurality of cylindrical battery cells in parallel with one of the two cylindrical battery cells stacked in step S40; Step S60: repeating steps S30 to S50 to connect and stack a plurality of the cylindrical battery cells in parallel.

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