Lamella cell assembly and method for producing a lamella cell assembly

Abstract

The application provides a laminated cell assembly and a preparation method thereof. The laminated cell assembly comprises at least one cell structure, and the cell structure comprises: a positive electrode unit comprising at least two positive electrode sheets electrically connected; a negative electrode unit comprising at least two negative electrode sheets electrically connected; and a diaphragm, which is folded and laminated, and comprises a plurality of diaphragm segments connected in sequence along the thickness direction, with each adjacent two diaphragm segments being arranged at intervals; wherein the at least two positive electrode sheets and the at least two negative electrode sheets are arranged alternately along the thickness direction, and the positive electrode sheets and the negative electrode sheets are separated by the diaphragm segments. The technical scheme of the application solves the problems of low efficiency and low qualified rate of the "Z-shaped lamination" in the prior art.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and more specifically, to a stacked cell assembly and a method for preparing the stacked cell assembly. Background Technology

[0002] A lithium-ion battery cell consists of a positive electrode, a separator, and a negative electrode. Currently, the cell is mainly a stacked structure.

[0003] Laminated battery cells often employ a "Z-type lamination" process: positive and negative electrode sheets are pre-prepared, the separator is directly oscillated in a "Z" shape, or the lamination stage oscillates in a "Z" shape (causing the separator to oscillate indirectly in a "Z" shape), and then the positive and negative electrode sheets are alternately placed on the separator. The bottleneck of this process is that it is difficult to effectively increase the mechanical cycle time of positive and negative electrode sheet transfer. Too many lamination times make it difficult to guarantee lamination accuracy, and the probability of the entire cell being scrapped due to the phase difference between the positive and negative electrode sheets increases.

[0004] Therefore, in order to overcome the problems of low yield and low efficiency in "Z-type stacking", this invention proposes a stacked cell assembly, which aims to solve the above problems at the same time. Summary of the Invention

[0005] The main objective of this invention is to provide a laminated cell assembly and a method for preparing the laminated cell assembly, so as to solve the problems of low efficiency and low yield of "Z-type lamination" in the prior art.

[0006] To achieve the above objectives, the present invention provides a stacked battery cell assembly, comprising at least one battery cell structure, the battery cell structure comprising: a positive electrode unit, comprising at least two positive electrode plates electrically connected; a negative electrode unit, comprising at least two negative electrode plates electrically connected; and a separator, which is bent to be stacked, the separator comprising a plurality of separator segments sequentially connected along the thickness direction, each adjacent two separator segments being spaced apart; wherein, at least two positive electrode plates and at least two negative electrode plates are alternately arranged along the thickness direction, and the positive electrode plates and negative electrode plates are separated by separator segments.

[0007] Furthermore, during the continuous bending of the separator, the positive electrode unit and the negative electrode unit are bent so that the positive electrode sheet and the negative electrode sheet are arranged alternately to form a cell structure, wherein the bending direction of the positive electrode unit and the negative electrode unit is at an angle to the bending direction of the separator.

[0008] Furthermore, the stacked cell assembly includes multiple cell structures arranged sequentially along the thickness direction. In two adjacent cell structures, on the adjacent end faces, the outermost part of one cell structure is a positive electrode sheet, and the outermost part of the other cell structure is a negative electrode sheet. The two separators in the two adjacent cell structures are either separately arranged or integrally formed into a continuous separator.

[0009] Furthermore, at least two positive electrode plates include a first positive electrode plate and a second positive electrode plate, and at least two negative electrode plates include a first negative electrode plate and a second negative electrode plate; the cell structure includes multiple positive electrode units and multiple negative electrode units corresponding to the multiple positive electrode units, with multiple first positive electrode plates and multiple first negative electrode plates alternately arranged, and multiple second positive electrode plates and multiple second negative electrode plates alternately arranged.

[0010] Furthermore, the positive electrode unit includes three positive electrode plates, the negative electrode unit includes three negative electrode plates, and the cell structure includes two separators corresponding to the two positive electrode plates or the two negative electrode plates. The cell structure is formed by continuously folding the separators and bending the positive electrode unit and the negative electrode unit.

[0011] Furthermore, the positive electrode unit also includes a bent positive electrode tab, through which two positive electrode pieces are electrically connected; and / or, the negative electrode unit also includes a bent negative electrode tab, through which two negative electrode pieces are electrically connected.

[0012] According to another aspect of the present invention, the present invention provides a method for preparing a laminated battery cell assembly, comprising: a first preparation step of electrically connecting a plurality of positive electrode sheets to prepare a positive electrode unit; a second preparation step of electrically connecting a plurality of negative electrode sheets to prepare a negative electrode unit; a lamination step of alternately arranging positive electrode sheets and negative electrode sheets along the thickness direction and continuously folding a separator; and a cutting step of cutting the separator to form a battery cell structure.

[0013] Furthermore, the positive electrode unit includes two electrically connected positive electrode plates, the negative electrode unit includes two electrically connected negative electrode plates, and the stacking step includes: continuously folding the separator to form a plurality of interconnected separator segments, separating the positive electrode plates and the negative electrode plates using the separator segments.

[0014] Furthermore, after the truncation step, the preparation method also includes stacking multiple cell structures, and setting two separators in two adjacent cell structures separately or integrally forming a continuous separator to form a stacked cell assembly.

[0015] Furthermore, the positive electrode unit includes a first positive electrode sheet and a second positive electrode sheet that are electrically connected, and the negative electrode unit includes a first negative electrode sheet and a second negative electrode sheet that are electrically connected. The stacking step includes: a stacking step of stacking multiple positive electrode units together and stacking multiple negative electrode units together; bending the stacked positive electrode units and negative electrode units so that the first positive electrode sheet and the second positive electrode sheet are set at an angle, and the first negative electrode sheet and the second negative electrode sheet are set at an angle; alternately arranging multiple first positive electrode sheets and multiple first negative electrode sheets on the folded separator; and alternately arranging multiple second positive electrode sheets and multiple second negative electrode sheets on the folded separator.

[0016] Furthermore, the positive electrode unit includes a first positive electrode, a second positive electrode, and a third positive electrode that are electrically connected; the negative electrode unit includes a first negative electrode, a second negative electrode, and a third negative electrode that are electrically connected; the cell structure includes a first separator and a second separator arranged in parallel; and the stacking step includes: placing the second positive electrode and the third positive electrode sequentially on the first separator and the second separator; folding the first separator and the second separator at a preset angle; placing the first negative electrode and the second negative electrode sequentially on the folded first separator and the second separator; folding the first separator and the second separator at a preset angle; folding the first positive electrode on the first separator; folding the first separator and the first positive electrode, the first negative electrode, and the second positive electrode disposed thereon on the second separator; and folding the third negative electrode on one side of the first separator or the second separator.

[0017] By applying the technical solution of this invention, compared with the traditional Z-type stacking, the positive electrode unit of this embodiment includes at least two connected positive electrode sheets, and the negative electrode unit includes at least two connected negative electrode sheets. On the one hand, compared with the separately set positive and negative electrode sheet units in the prior art, when transferring the same number of positive and negative electrode sheets, this application can reduce the number of transfers of the positive and negative electrode units during the stacking process, thereby improving the stacking efficiency. On the other hand, the reduction in the number of transfers of the positive and negative electrode units can reduce the risk of the phase difference between the positive and negative electrode units exceeding the standard, that is, it can reduce the probability of the relative position deviation of the positive and negative electrode units, thereby improving the stacking yield. Therefore, the stacked cell assembly of this embodiment solves the problems of low efficiency and low yield in "Z-type stacking". Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 A schematic diagram of the positive electrode unit of a stacked cell assembly according to an embodiment of the present invention is shown;

[0020] Figure 2 A schematic diagram of the negative electrode unit of a stacked cell assembly according to an embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram of the cell structure of the stacked cell assembly according to Embodiment 1 of the present invention is shown;

[0022] Figure 4 A schematic diagram of the structure of a stacked cell assembly according to Embodiment 1 of the present invention is shown;

[0023] Figure 5A schematic diagram of the structure of the stacked cell assembly according to Embodiment 2 of the present invention is shown;

[0024] Figure 6 This diagram illustrates a stacked structure of multiple positive electrode units in a laminated cell assembly according to Embodiment 3 of the present invention.

[0025] Figure 7 This diagram shows a schematic of the structure of multiple positive and multiple negative electrode units of the stacked cell assembly according to Embodiment 3 of the present invention after bending.

[0026] Figure 8 A schematic diagram of the stacked cell assembly of Embodiment 3 of the present invention during the stacking process is shown;

[0027] Figure 9 This shows another structural schematic diagram of the stacked cell assembly according to Embodiment 3 of the present invention during the stacking process;

[0028] Figure 10 A schematic diagram of the stacked cell assembly of Embodiment 4 of the present invention during the stacking process is shown;

[0029] Figure 11 A schematic diagram of the stacked cell assembly of Embodiment 5 of the present invention during the stacking process is shown;

[0030] Figure 12 This shows another structural schematic diagram of the stacked cell assembly of Embodiment 5 of the present invention during the stacking process;

[0031] Figure 13 A schematic diagram of the stacked cell assembly of Embodiment Six of the present invention during the stacking process is shown;

[0032] Figure 14 A schematic flowchart illustrating a method for fabricating a stacked battery cell assembly according to an embodiment of the present invention is shown; and

[0033] Figure 15 The diagram shows a schematic flowchart of the stacking steps of the stacked cell assembly according to Embodiments 3 and 4 of the present invention.

[0034] The above figures include the following reference numerals:

[0035] 10. Positive electrode unit; 101. Positive electrode plate; 102. Positive electrode tab; 103. First positive electrode plate; 104. Second positive electrode plate; 105. First positive electrode plate; 106. Second positive electrode plate; 107. Third positive electrode plate; 20. Negative electrode unit; 201. Negative electrode plate; 202. Negative electrode tab; 203. First negative electrode plate; 204. Second negative electrode plate; 205. First negative electrode plate; 206. Second negative electrode plate; 207. Third negative electrode plate; 30. Separator; 31. Separator segment; 40. Cell structure; 50. First separator; 60. Second separator. Detailed Implementation

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] It should be noted that, in the embodiments of the present invention, the preset angle is approximately 180°.

[0038] This invention proposes a stacked cell assembly, which divides a single electrode unit into several connected electrodes, and then combines the multiple stacking of the separator (such as Z-shaped folding) to obtain the cell structure. The cell structure can be directly stacked to obtain a stacked cell assembly with the required number of layers.

[0039] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 9 , Figure 12 and Figure 13 As shown, an embodiment of the present invention provides a stacked battery cell assembly. The stacked battery cell assembly includes at least one cell structure 40, which includes a positive electrode unit 10, a negative electrode unit 20, and a continuously folded separator 30. The positive electrode unit 10 includes at least two electrically connected positive electrode plates 101; the negative electrode unit 20 includes at least two electrically connected negative electrode plates 201; the separator 30 is bent to form a stack, and the separator 30 includes a plurality of separator segments 31 connected sequentially along the thickness direction, with each adjacent pair of separator segments 31 spaced apart; wherein at least two positive electrode plates 101 and at least two negative electrode plates 201 are alternately arranged along the thickness direction, and the positive electrode plates 101 and the negative electrode plates are separated by the separator segments 31.

[0040] In the above technical solution, compared with the traditional Z-type stacking, the positive electrode unit 10 of this embodiment includes at least two connected positive electrode sheets 101, and the negative electrode unit 20 includes at least two connected negative electrode sheets 201. On the one hand, compared with the separately set positive and negative electrode sheet units in the prior art, when transferring the same number of positive and negative electrode sheets, this application can reduce the number of transfers of the positive electrode unit 10 and the negative electrode unit 20 during the stacking process, thereby improving the stacking efficiency. On the other hand, the reduction in the number of transfers of the positive electrode unit 10 and the negative electrode unit 20 can reduce the risk of the phase difference between the positive electrode unit 10 and the negative electrode unit 20 exceeding the standard, that is, it can reduce the probability of the relative position deviation of the positive electrode unit 10 and the negative electrode unit 20, thereby improving the stacking yield. Therefore, the stacked cell assembly of this embodiment solves the problems of low efficiency and low yield in "Z-type stacking".

[0041] Furthermore, by folding the positive electrode 101 and the negative electrode 201, a cell structure 40 is obtained. Then, by stacking any number of cell structures 40, a stacked cell assembly can be obtained, which can also effectively improve the stacking efficiency.

[0042] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 9 , Figure 12 and Figure 13 As shown, during the continuous bending of the separator 30, the positive electrode unit 10 and the negative electrode unit 20 are bent so that the positive electrode sheet 101 and the negative electrode sheet 201 are alternately arranged to form the cell structure 40. The bending direction of the positive electrode unit 10 and the negative electrode unit 20 is at an angle to the bending direction of the separator 30.

[0043] In the above technical solution, by setting up the bent positive electrode unit 10 and negative electrode unit 20, one positive electrode unit 10 can form two positive electrode sheets, and one negative electrode unit 20 can form two negative electrode sheets. In this way, compared with the separately set positive and negative electrode sheet units in the prior art, when transferring the same number of positive and negative electrode sheets, this application can reduce the number of transfers of positive electrode unit 10 and negative electrode unit 20 during the stacking process, thereby improving the stacking efficiency.

[0044] Specifically, the bending directions of the positive electrode unit 10 and the negative electrode unit 20 form an angle with the bending direction of the separator 30. This ensures that the bending of the positive and negative electrode units and the bending of the separator do not interfere with each other. Preferably, the bending angle of the separator 30 is 90°, the bending angle of the positive electrode unit 10 is 90°, and the bending angle of the negative electrode unit 20 is 90°.

[0045] Example 1

[0046] like Figure 3 and Figure 4 As shown, in an embodiment of the present invention, the stacked cell assembly includes a plurality of cell structures 40 arranged sequentially along the thickness direction. On the adjacent end faces of two adjacent cell structures 40, the outermost part of one cell structure 40 is a positive electrode 101, and the outermost part of the other cell structure 40 is a negative electrode 201. The two separators 30 in the two adjacent cell structures 40 are separately arranged.

[0047] In the above technical solution, by stacking multiple cell structures 40, a stacked cell assembly can be obtained, thereby effectively improving the stacking efficiency.

[0048] Specifically, in Embodiment 1 of the present invention, the cell structure 40 includes a positive electrode unit 10 and a negative electrode unit 20.

[0049] It should be noted that the present invention does not limit the number of stacked cells in the cell structure 40.

[0050] like Figure 1 As shown, in an embodiment of the present invention, the positive electrode unit 10 further includes a bent positive electrode tab 102, through which two positive electrode plates 101 are electrically connected. This not only enables electrical connection between the two positive electrode plates 101, but also prevents the active material on the positive electrode plates 101 from falling off when the positive electrode unit 10 is bent, thus avoiding affecting the yield of the stacked cell assembly.

[0051] like Figure 2 As shown, in an embodiment of the present invention, the negative electrode unit 20 further includes a bent negative electrode tab 202, through which two negative electrode sheets 201 are electrically connected. This not only enables electrical connection between the two negative electrode sheets 201, but also prevents the active material on the negative electrode sheets 201 from falling off when the negative electrode unit 20 is bent, thus avoiding affecting the yield of the stacked cell assembly.

[0052] Specifically, in Embodiment 1 of the present invention, the positive electrode unit 10 includes two positive electrode plates 101, and the negative electrode unit 20 includes two negative electrode plates 201. This reduces the number of transfers between the positive electrode unit 10 and the negative electrode unit 20 during the stacking process, thereby improving the stacking efficiency.

[0053] Specifically, in Embodiment 1 of the present invention, the positive electrode 101 is made of aluminum foil, and is formed by coating positive electrode active material on its upper and lower surfaces, and then drying and rolling, while the positive electrode tab 102 is aluminum foil without positive electrode active material coating.

[0054] Specifically, in Embodiment 1 of the present invention, the negative electrode sheet 201 is made of copper foil, and is formed by coating the upper and lower surfaces with negative electrode active material and then drying and rolling, while the negative electrode tab 202 is a copper foil without negative electrode active material coating.

[0055] Example 2

[0056] like Figure 5 As shown, the difference between the stacked cell assembly of Embodiment 2 and Embodiment 1 is that the separator 30 is integrally formed to form a continuous separator. Thus, by providing a continuously folded separator 30 and folding multiple positive electrode units 10 and multiple negative electrode units 20 onto each separator segment 31 in the continuous separator, a cell structure 40 with multiple positive electrode units 10 and multiple negative electrode units 20 can be formed to create a stacked cell assembly. This eliminates the need for subsequent stacking of multiple cell structures 40, simplifying the processing and improving processing efficiency.

[0057] It should be noted that the stacked cell assembly in this embodiment includes a cell structure 40, and the cell structure 40 includes multiple positive electrode units 10 and multiple negative electrode units 20.

[0058] The present invention does not limit the number of positive electrode plates 101 and negative electrode plates 201 stacked in the cell structure 40.

[0059] The other structures in this second embodiment are the same as those in the first embodiment, and will not be described again here.

[0060] Example 3

[0061] like Figures 6 to 9 As shown, in Embodiment 3 of the present invention, at least two positive electrode plates 101 include a first positive electrode plate 103 and a second positive electrode plate 104, and at least two negative electrode plates 201 include a first negative electrode plate 203 and a second negative electrode plate 204; the cell structure 40 includes a plurality of positive electrode units 10 and a plurality of negative electrode units 20 corresponding to the plurality of positive electrode units 10, the plurality of first positive electrode plates 103 and the plurality of first negative electrode plates 203 are alternately arranged, and the plurality of second positive electrode plates 104 and the plurality of second negative electrode plates 204 are alternately arranged.

[0062] In the above technical solution, compared with the traditional Z-shaped stacking where positive electrode unit 10 and negative electrode unit 20 are placed alternately, this embodiment three can first alternately set multiple first positive electrode plates 103 and multiple first negative electrode plates 203, and then alternately set multiple second positive electrode plates 104 and multiple second negative electrode plates 204. Alternatively, multiple second positive electrode plates 104 and multiple second negative electrode plates 204 can be alternately set first, and then multiple first positive electrode plates 103 and multiple first negative electrode plates 203 can be alternately set. In this way, the positive electrode unit 10 and negative electrode unit 20 can be stacked together first, and the positive electrode unit 10 and negative electrode unit 20 can be fixed and formed into an L-shape. Then, multiple positive electrode plates 101 and multiple negative electrode plates 201 are alternately placed, thereby improving the stacking accuracy of each positive electrode plate 101 and each negative electrode plate 201, thereby improving the stacking accuracy and thus improving the stacking qualification rate.

[0063] Specifically, such as Figure 9 As shown, in Embodiment 3 of the present invention, the first positive electrode 103 and the first negative electrode 203 are both located below the second positive electrode 104 and the second negative electrode 204.

[0064] Example 4

[0065] like Figure 10 As shown, the difference between the stacked cell assembly of Embodiment 4 and Embodiment 3 is that the first positive electrode 103 and the first negative electrode 203 are both located above the second positive electrode 104 and the second negative electrode 204.

[0066] The other structures in this embodiment four are the same as those in embodiment three, and will not be described again here.

[0067] Example 5

[0068] like Figure 11 and Figure 12 As shown, in Embodiment 5 of the present invention, the positive electrode unit 10 includes three positive electrode plates 101, the negative electrode unit 20 includes three negative electrode plates 201, and the cell structure 40 includes two separators 30 corresponding to the two positive electrode plates 101 or the two negative electrode plates 201. The cell structure 40 is formed by continuously folding the separators 30 and bending the positive electrode unit 10 and the negative electrode unit 20.

[0069] In the above technical solution, the positive electrode unit 10 includes three positive electrode plates 101 and the negative electrode unit 20 includes three negative electrode plates 201. This can further reduce the number of transfers between the positive electrode unit 10 and the negative electrode unit 20, thereby greatly reducing the number of stacking operations and improving the stacking efficiency.

[0070] Specifically, in this fifth embodiment, multiple cell structures 40 are stacked to form a stacked cell assembly.

[0071] Specifically, in this fifth embodiment, one of the three negative electrode plates 201 is located above the three positive electrode plates 101.

[0072] Example 6

[0073] like Figure 13 As shown, the difference between the stacked cell assembly of Embodiment Six of the present invention and Embodiment Five is that one of the three negative electrode plates 201 is located below the three positive electrode plates 101.

[0074] The other structures in this sixth embodiment are the same as those in the fifth embodiment, and will not be described again here.

[0075] like Figure 14As shown, an embodiment of the present invention provides a method for fabricating a laminated battery cell assembly. The method for fabricating the laminated battery cell assembly includes: a first fabrication step of electrically connecting multiple positive electrode sheets 101 to fabricate a positive electrode unit 10; a second fabrication step of electrically connecting multiple negative electrode sheets 201 to fabricate a negative electrode unit 20; a lamination step of alternately arranging the positive electrode sheets 101 and the negative electrode sheets 201 along the thickness direction and continuously folding the separator 30; and a cutting step of cutting the separator 30 to form a battery cell structure 40.

[0076] In the above technical solution, compared with the traditional Z-type stacking method, this embodiment uses multiple positive electrode sheets 101 electrically connected to form a positive electrode unit 10, and multiple negative electrode sheets 201 electrically connected to form a negative electrode unit 20. This reduces the number of transfers between the positive electrode unit 10 and the negative electrode unit 20 during the stacking process, thereby improving stacking efficiency. Furthermore, the reduced number of transfers reduces the risk of phase difference exceeding the standard between the positive electrode unit 10 and the negative electrode unit 20, meaning it lowers the probability of relative positional deviations between them, thus improving the stacking yield. Therefore, the stacked cell assembly of this embodiment solves the problems of low efficiency and low yield in the "Z-type stacking" method.

[0077] In an embodiment of the present invention, the positive electrode unit 10 includes two positive electrode plates 101 electrically connected, the negative electrode unit 20 includes two negative electrode plates 201 electrically connected, and the stacking step includes: continuously folding the separator 30 to form a plurality of interconnected separator segments 31, and separating the positive electrode plate 101 and the negative electrode plate 201 by means of the separator segments 31.

[0078] In the above technical solution, on the one hand, a cell structure 40 can be formed; on the other hand, during the stacking process, the number of transfers between the positive electrode unit 10 and the negative electrode unit 20 can be reduced, thereby improving the stacking efficiency.

[0079] Preferably, in an embodiment of the present invention, the diaphragm 30 is continuously folded in a Z-shape.

[0080] Preferably, in the method for preparing the stacked cell assembly of Embodiment 1, the stacking step includes: first, taking a positive electrode unit 10 and placing one of the two positive electrode plates 101 on the separator 30; second, folding the separator 30 at a preset angle; third, taking a negative electrode unit 20 and placing one of the two negative electrode plates 201 on the folded separator 30; fourth, folding the separator 30 at a preset angle; fifth, folding the other positive electrode plate 101 on the separator 30; sixth, folding the separator 30 at a preset angle; and seventh, folding the other negative electrode plate 201 on the separator 30. This forms the cell structure 40.

[0081] It should be noted that in Embodiment 1 of the present invention, the preset angle is approximately 180°.

[0082] like Figure 14 As shown, in the method of preparation embodiment one, after the truncation step, the preparation method further includes stacking multiple cell structures 40, and separately setting the two separators 30 in two adjacent cell structures 40. In this way, multiple cell structures 40 can be stacked to form a stacked cell assembly with multiple positive electrode units 10 and multiple negative electrode units 20, thereby effectively improving the stacking efficiency.

[0083] Preferably, in Embodiment 2, the positive electrode unit 10 includes two electrically connected positive electrode plates 101, and the negative electrode unit 20 includes two electrically connected negative electrode plates 201. In the method for preparing the stacked cell assembly of Embodiment 2, the stacking step includes: first, taking one positive electrode unit 10 and placing one of the two positive electrode plates 101 on the separator 30; second, folding the separator 30 at a preset angle; third, taking one negative electrode unit 20 and placing one of the two negative electrode plates 201 on the folded separator 30; fourth, folding the separator 30 at a preset angle; fifth, placing the other... A positive electrode 101 is folded onto the separator 30; sixth, the separator 30 is folded at a preset angle; seventh, another negative electrode 201 is folded onto the separator 30; eighth, the separator 30 is folded at a preset angle; ninth, another positive electrode unit 10 is taken, and one of the two positive electrode 101s is placed on the separator 30; tenth, the separator 30 is folded at a preset angle; eleventh, another negative electrode unit 20 is taken, and one of the two negative electrode 201s is placed on the folded separator 30; twelfth, the above steps are repeated until the desired number of stacked cell structures 40 is obtained. In this way, the stacked cell assembly, with a single integrally formed continuous separator, can have multiple positive electrode units 10 and multiple negative electrode units 20, thereby eliminating the need for subsequent stacking of multiple cell structures 40, simplifying the processing and improving processing efficiency.

[0084] like Figures 6 to 9 as well as Figure 15As shown, in the embodiments of the present invention, the positive electrode unit 10 includes a first positive electrode 103 and a second positive electrode 104 electrically connected, and the negative electrode unit 20 includes a first negative electrode 203 and a second negative electrode 204 electrically connected. In the method for preparing the stacked cell assembly of Embodiments 3 and 4, the stacking step includes: a stacking step of stacking multiple positive electrode units 10 together and stacking multiple negative electrode units 20 together; bending the stacked positive electrode units 10 and negative electrode units 20 so that the first positive electrode 103 and the second positive electrode 104 are set at an angle, and the first negative electrode 203 and the second negative electrode 204 are set at an angle; alternatingly arranging multiple first positive electrode units 103 and multiple first negative electrode units 203 on the folded separator 30; and alternatingly arranging multiple second positive electrode units 104 and multiple second negative electrode units 204 on the folded separator 30.

[0085] In the above technical solution, compared with the traditional Z-type stacking method which uses alternating placement of positive electrode unit 10 and negative electrode unit 20, in the method of preparing the stacked cell assembly of Embodiments 3 and 4, the positive electrode unit 10 and negative electrode unit 20 are first stacked together, then fixed and bent, and then the positive electrode unit 10 and negative electrode unit 20 are placed alternately, which can improve the stacking accuracy and thus improve the stacking qualification rate.

[0086] Specifically, such as Figure 7 As shown, the first positive electrode 103 and the second positive electrode 104 are arranged at an angle, and the first negative electrode 203 and the second negative electrode 204 are arranged at an angle, which means that the stacked positive electrode unit 10 and negative electrode unit 20 are bent into L-shapes respectively.

[0087] Specifically, such as Figure 7 and Figure 8 As shown, alternatingly arranging multiple first positive electrode plates 103 and multiple first negative electrode plates 203 on the folded separator 30 specifically includes: first placing the separator 30 between the bent positive electrode unit 10 and negative electrode unit 20, then arranging the first positive electrode plates 103 on the separator 30, and then arranging the separator 30 in a manner consistent with... Figure 7 The vertical plane is folded inwards, and then the first negative electrode 203 is placed on the folded diaphragm 30.

[0088] Specifically, such as Figure 9 As shown, in Figure 8 Based on this, the second positive electrode 104 and the second negative electrode 204 are folded upwards respectively until the cell structure 40 is obtained, thereby preparing the cell structure 40 of Example 3.

[0089] Specifically, such as Figure 10 As shown, in Figure 8Based on this, the second positive electrode 104 and the second negative electrode 204 are folded downwards respectively until the cell structure 40 is obtained, thereby preparing the cell structure 40 of Example 4.

[0090] Of course, in alternative embodiments not shown in the accompanying drawings, it is also possible to... Figure 8 Based on this, a portion of the second positive electrode 104 and the second negative electrode 204 are folded upwards, and another portion of the second positive electrode 104 and the other portion of the second negative electrode 204 are folded downwards, as long as the second positive electrode 104 and the second negative electrode 204 are alternately arranged on both sides of the separator 30.

[0091] Regarding preferred embodiments three and four, the present invention does not limit the initial state ( Figure 6 The number of stacked layers of positive electrode unit 10 and negative electrode unit 20.

[0092] like Figures 11 to 13 As shown, in embodiments five and six of the present invention, the positive electrode unit 10 includes a first positive electrode 105, a second positive electrode 106, and a third positive electrode 107 electrically connected; the negative electrode unit 20 includes a first negative electrode 205, a second negative electrode 206, and a third negative electrode 207 electrically connected; and the cell structure 40 includes a first separator 50 and a second separator 60 arranged in parallel. In the method for preparing the stacked cell assembly of embodiments five and six, the stacking step includes: placing the second positive electrode 106 and the third positive electrode 107 sequentially on the first separator 50 and the second separator 60. Fold the first diaphragm 50 and the second diaphragm 60 at a preset angle; place the first negative electrode 205 and the second negative electrode 206 on the folded first diaphragm 50 and the second diaphragm 60 in sequence; fold the first diaphragm 50 and the second diaphragm 60 at a preset angle; fold the first positive electrode 105 on the first diaphragm 50; fold the first diaphragm 50 and the first positive electrode 105, the first negative electrode 205 and the second positive electrode 106 disposed thereon on the folded second diaphragm 60; fold the third negative electrode 207 on one side of the first diaphragm 50 or the second diaphragm 60.

[0093] In the above technical solution, both the positive electrode unit 10 and the negative electrode unit 20 include three positive and negative electrode plates (first positive electrode plate 105, second positive electrode plate 106 and third positive electrode plate 107, and first negative electrode plate 205, second negative electrode plate 206 and third negative electrode plate 207), which can further reduce the number of transfers in the positive electrode unit 10 and the negative electrode unit 20, which greatly reduces the number of stacking operations and thus improves the stacking efficiency.

[0094] Specifically, such as Figure 11As shown, folding the first diaphragm 50 and the first positive electrode 105, the first negative electrode 205 and the second positive electrode 106 disposed thereon onto the folded second diaphragm 60 means that the first diaphragm 50 and the first positive electrode 105, the first negative electrode 205 and the second positive electrode 106 disposed thereon are rotated 180 degrees clockwise and then attached to the second diaphragm 60.

[0095] Preferably, such as Figure 12 As shown, the third negative electrode 207 is folded upwards, that is, the third negative electrode 207 is folded onto the first separator 50, thereby preparing the cell structure 40 of Example 5.

[0096] Preferably, such as Figure 13 As shown, the third negative electrode 207 is folded downwards, that is, the third negative electrode 207 is folded onto the second separator 60, thereby preparing the cell structure 40 of Example 6.

[0097] Specifically, by stacking multiple cell structures 40 from Examples 5 and 6, a stacked cell assembly can be obtained. Furthermore, this invention does not limit the number of cell structures 40 stacked in the stacked cell assembly.

[0098] It should be noted that the present invention can yield a variety of derivative solutions, such as the positive electrode unit 10 containing a number of (>3) positive electrode plates, the negative electrode unit 20 containing a number of (>3) negative electrode plates, and the stacked cell assembly can be formed by stacking a number of cell structures 40, and the structure of the cell structure 40 can also be different, which can greatly improve the adaptability of engineering manufacturing.

[0099] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: Compared with the traditional Z-type stacking, the positive electrode unit of this embodiment includes at least two connected positive electrode sheets, and the negative electrode unit includes at least two connected negative electrode sheets. On the one hand, compared with the separately set positive and negative electrode sheet units in the prior art, when transferring the same number of positive and negative electrode sheets, the present application can reduce the number of transfers of the positive and negative electrode units during the stacking process, thereby improving the stacking efficiency. On the other hand, the reduction in the number of transfers of the positive and negative electrode units can reduce the risk of the phase difference between the positive and negative electrode units exceeding the standard, that is, it can reduce the probability of the relative position deviation of the positive and negative electrode units, thereby improving the stacking yield. Therefore, the stacked cell assembly of this embodiment solves the problems of low efficiency and low yield in "Z-type stacking".

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A stacked cell assembly, characterized in that, Includes at least one cell structure (40), said cell structure (40) comprising: The diaphragm (30) is bent and stacked. The diaphragm (30) includes a plurality of diaphragm segments (31) connected sequentially along the thickness direction, with each pair of adjacent diaphragm segments (31) spaced apart. The positive electrode unit (10) includes at least three positive electrode plates (101) electrically connected, and the negative electrode unit (20) includes at least three negative electrode plates (201) electrically connected. The at least three positive electrode plates (101) and the at least three negative electrode plates (201) are alternately arranged along the thickness direction, and the positive electrode plates (101) and the negative electrode plates (201) are separated by the separator section (31). During the continuous bending of the separator (30), the positive electrode unit (10) and the negative electrode unit (20) are bent so that the positive electrode plates (101) and the negative electrode plates (201) are alternately arranged to form the cell structure (40). The bending direction of the positive electrode unit (10) and the negative electrode unit (20) is at an angle to the bending direction of the separator (30). The cell structure (40) includes at least two separators (30) corresponding to at least two positive electrode plates (101) or at least two negative electrode plates (201), and the cell structure (40) is formed by continuously folding the separators (30) and bending the positive electrode unit (10) and the negative electrode unit (20).

2. The laminated cell assembly according to claim 1, characterized in that, The stacked cell assembly includes a plurality of cell structures (40) arranged sequentially along the thickness direction. In two adjacent cell structures (40), on the adjacent end faces, the outermost part of one cell structure (40) is a positive electrode (101), and the outermost part of the other cell structure (40) is a negative electrode (201). The two separators (30) in the two adjacent cell structures (40) are either separately arranged or integrally formed into a continuous separator.

3. The laminated cell assembly according to claim 1 or 2, characterized in that, The positive electrode unit (10) further includes a bent positive electrode tab (102), through which the two positive electrode plates (101) are electrically connected; and / or, The negative electrode unit (20) also includes a bent negative electrode tab (202), and the two negative electrode pieces (201) are electrically connected through the negative electrode tab (202).

4. A method for preparing a stacked battery cell assembly, characterized in that, The laminated cell assembly of any one of claims 1 to 3 is prepared using the method for preparing the laminated cell assembly, wherein the method for preparing the laminated cell assembly includes: The first preparation step is to electrically connect multiple positive electrode plates (101) to prepare a positive electrode unit (10); The second preparation step is to electrically connect multiple negative electrode sheets (201) to prepare a negative electrode unit (20); The positive electrode (101) and negative electrode (201) are alternately arranged along the thickness direction, and the separator (30) is continuously folded in a stacking process. The cutting step of cutting off the diaphragm (30) to form the cell structure (40).

5. The method for preparing a stacked cell assembly according to claim 4, characterized in that, After the cutting step, the preparation method further includes stacking a plurality of the cell structures (40) and making two of the separators (30) in two adjacent cell structures (40) separately set or integrally formed into a continuous separator to form the stacked cell assembly.

6. The method for preparing a stacked cell assembly according to claim 4, characterized in that, The positive electrode unit (10) includes a first positive electrode plate (105), a second positive electrode plate (106), and a third positive electrode plate (107) electrically connected; the negative electrode unit (20) includes a first negative electrode plate (205), a second negative electrode plate (206), and a third negative electrode plate (207) electrically connected; the cell structure (40) includes a first separator (50) and a second separator (60) arranged in parallel; the stacking step includes: The second positive electrode (106) and the third positive electrode (107) are placed sequentially on the first diaphragm (50) and the second diaphragm (60); Fold the first diaphragm (50) and the second diaphragm (60) at a predetermined angle; The first negative electrode plate (205) and the second negative electrode plate (206) are placed sequentially on the folded first diaphragm (50) and second diaphragm (60); Fold the first diaphragm (50) and the second diaphragm (60) at a predetermined angle; Fold the first positive electrode plate (105) onto the first separator (50); The first diaphragm (50) and the first positive electrode (105), the first negative electrode (205) and the second positive electrode (106) disposed thereon are folded onto the second diaphragm (60); The third negative electrode (207) is folded onto one side of the first diaphragm (50) or the second diaphragm (60).

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