Battery cell lamination process, battery cell lamination device, and battery cell

Abstract

The disclosure provides an electric core laminating process, an electric core laminating device and an electric core, and relates to the technical field of lithium batteries. The electric core laminating process comprises the following steps: inserting a cut positive electrode sheet between a first diaphragm and a second diaphragm to form a positive electrode composite sheet; inserting the positive electrode composite sheet between an uncut first negative electrode sheet and a second negative electrode sheet; forming a third diaphragm on the side of the first negative electrode sheet away from the positive electrode composite sheet and forming a fourth diaphragm on the side of the second negative electrode sheet away from the positive electrode composite sheet to form a composite electrode sheet; cutting the composite electrode sheet to form a composite unit sheet; and alternately laminating the composite unit sheet and the cut single positive electrode sheet to form an electric core, so that the lamination efficiency can be improved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and more specifically, to a cell stacking process, a cell stacking device, and a cell. Background Technology

[0002] Most existing lamination processes involve cutting the positive and negative electrodes and feeding them into wafers, then using a separator to drive the hot rolling of the positive and negative electrode wafers for lamination. This process uses robotic arms to alternately stack the wafers, resulting in low efficiency. Furthermore, the last negative electrode wafer requires a separate composite wafer buffer, impacting equipment efficiency and quality. Summary of the Invention

[0003] The present invention aims to provide, for example, a cell stacking process, a cell stacking apparatus, and a cell that can improve stacking efficiency and quality.

[0004] The embodiments of the present invention can be implemented as follows:

[0005] In a first aspect, the present invention provides a cell stacking process, comprising:

[0006] The cut positive electrode sheet is inserted between the first and second separators to form a positive electrode composite sheet;

[0007] Insert the positive electrode composite sheet between the uncut first negative electrode sheet and the second negative electrode sheet;

[0008] A third separator is formed on the side of the first negative electrode sheet away from the positive electrode composite sheet, and a fourth separator is formed on the side of the second negative electrode sheet away from the positive electrode composite sheet, thus forming a composite electrode sheet;

[0009] The composite electrode sheet is cut to form a composite unit sheet;

[0010] The composite unit wafers and cut single positive electrode wafers are alternately stacked to form a battery cell.

[0011] In an optional implementation, the step of forming the positive electrode composite sheet includes:

[0012] After the step of inserting the cut positive electrode sheet between the first and second separators, the first separator, the positive electrode sheet, and the second separator are hot-pressed together.

[0013] In an optional implementation, the step of forming the positive electrode composite sheet includes:

[0014] After the step of inserting the cut positive electrode sheet between the first and second separators, the first separator and the second separator are laminated between two adjacent positive electrode sheets.

[0015] In an optional embodiment, the positive electrode sheet includes a first positive electrode sheet and a second positive electrode sheet, and the step of inserting the cut positive electrode sheet between the first diaphragm and the second diaphragm includes:

[0016] Cut the first positive electrode and the second positive electrode separately;

[0017] The cut first positive electrode and the second positive electrode are alternately inserted between the first diaphragm and the second diaphragm.

[0018] In an optional implementation, the step of forming the composite electrode includes:

[0019] After the steps of forming a third separator on the side of the first negative electrode sheet away from the positive electrode composite sheet and forming a fourth separator on the side of the second negative electrode sheet away from the positive electrode composite sheet, the third separator, the first negative electrode sheet, the positive electrode composite sheet, the second negative electrode sheet and the fourth separator are hot-pressed.

[0020] In an optional embodiment, after the step of cutting the composite electrode sheet to form a composite unit sheet, the process further includes:

[0021] Clean the cut surfaces of the composite electrode.

[0022] In an optional embodiment, the step of alternately stacking the composite unit sheet and the cut single positive electrode sheet to form a battery cell includes:

[0023] Transfer the composite unit wafer to the stacking stage;

[0024] Cut the third positive electrode sheet to form a single positive electrode sheet;

[0025] Transfer a single positive electrode sheet to the stacking stage; wherein the composite unit sheet and the single positive electrode sheet are stacked alternately.

[0026] In a second aspect, the present invention provides a battery cell stacking device, comprising:

[0027] The first composite mechanism is used to form the positive electrode composite sheet;

[0028] The second composite mechanism is used to form the composite electrode sheet;

[0029] A cutting mechanism is used to cut the composite electrode sheet into composite unit sheets;

[0030] The stacking mechanism is used to alternately stack the composite unit sheet and the cut single positive electrode sheet onto the stacking table.

[0031] In an optional embodiment, the first composite mechanism includes a positive electrode unwinding unit, a positive electrode cutting unit, a first diaphragm conveying unit, a first hot pressing unit, and a second hot pressing unit arranged sequentially.

[0032] The second composite mechanism includes a negative electrode unwinding unit, a second diaphragm conveying unit, and a third hot pressing unit arranged sequentially; the negative electrode unwinding unit is located between the second hot pressing unit and the second diaphragm conveying unit.

[0033] In an optional embodiment, a cleaning unit is also included, which is located on the side of the cutting mechanism away from the third hot pressing unit.

[0034] Thirdly, the present invention provides a battery cell manufactured using the battery cell stacking process as described in any of the foregoing embodiments, or manufactured using the battery cell stacking apparatus as described in any of the foregoing embodiments.

[0035] The beneficial effects of the embodiments of the present invention include, for example:

[0036] The cell stacking process provided in this invention first forms a positive electrode composite sheet, then forms a composite electrode sheet consisting of a positive electrode sheet, a negative electrode sheet, and a separator. The composite electrode sheet is then cut into composite unit sheets, which are alternately stacked with single positive electrode sheets to form a cell. Notably, there is no need to separately cut the negative electrode sheet; the negative electrode sheet is continuously fed in, greatly improving stacking efficiency. Furthermore, using the cell stacking process of this invention, the last negative electrode sheet does not require a separate composite sheet buffer, which is beneficial for improving equipment efficiency and quality.

[0037] The battery cell stacking apparatus provided in this invention employs a first composite mechanism to form a positive electrode composite sheet; a second composite mechanism to form a composite electrode sheet; a cutting mechanism to cut the composite electrode sheet into composite unit sheets; and a stacking mechanism to alternately stack the composite unit sheets and the cut single positive electrode sheets onto a stacking table to achieve battery cell stacking with high efficiency. This battery cell stacking apparatus eliminates the need to cut negative electrode sheets, and the last negative electrode sheet does not require a separate composite sheet buffer, which improves equipment efficiency and quality.

[0038] The battery cells provided in this embodiment of the invention are manufactured using the above-mentioned battery cell stacking process or battery cell stacking device, resulting in high battery cell production efficiency and good quality. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the cell stacking device provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of the positive electrode composite sheet formed in the cell stacking process provided in the embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of the positive electrode composite sheet formed in the cell stacking process provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of the composite unit wafer formed in the cell stacking process provided in the embodiments of the present invention;

[0044] Figure 5 This is a schematic diagram of the alternating stacking of single positive electrode sheets and composite unit sheets in the cell stacking process provided in the embodiments of the present invention.

[0045] Icons: 100 - Cell stacking device; 110 - First composite mechanism; 111 - Positive electrode unwinding unit; 113 - Positive electrode cutting unit; 115 - First separator conveying unit; 117 - First hot pressing unit; 119 - Second hot pressing unit; 120 - Second composite mechanism; 121 - Negative electrode unwinding unit; 123 - Second separator conveying unit; 125 - Third hot pressing unit; 130 - Cutting mechanism; 140 - Stacking mechanism; 141 - First robotic arm; 143 - Second robotic arm; 1 50 - Cleaning unit; 160 - Stacking table; 101 - First positive electrode sheet; 103 - Second positive electrode sheet; 104 - Spacer; 105 - Third positive electrode sheet; 107 - Single positive electrode sheet; 201 - First separator; 203 - Second separator; 205 - First negative electrode sheet; 207 - Second negative electrode sheet; 211 - Third separator; 213 - Fourth separator; 220 - Composite unit sheet; 225 - Positive electrode composite sheet; 230 - Positive electrode sheet conveying mechanism; 231 - Positive electrode sheet unwinding roller; 233 - Cutting unit. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0048] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0049] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0050] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0051] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0052] In existing battery cell stacking processes, most involve feeding cut positive electrode sheets onto one side of the separator and cut negative electrode sheets onto the other side. The separator then drives the positive and negative electrode sheets to be thermally pressed together. The resulting composite units are then cut and stacked alternately. This method is limited by the conveyor speeds of the positive, negative, and separator sheets, resulting in low stacking efficiency. Furthermore, the last negative electrode sheet requires a separate composite buffer, meaning it must be fabricated and stored in a buffer box before the final cell stacking, severely impacting equipment efficiency and quality.

[0053] Understandably, in existing technologies, positive and negative electrode sheets are clamped and fed, and then cut separately. The cyclic return of the grippers and cutter not only limits the conveyor belt's speed, but also results in repetitive return motions, leading to low time utilization and ineffective return strokes. Taking the conveying of 220mm electrode sheets as an example, if the overall feeding speed is ≥0.6s / pcs, then the theoretical maximum efficiency of the entire equipment is 0.3s / pcs.

[0054] To overcome at least one deficiency of the prior art, embodiments of the present invention provide a cell stacking process that eliminates the need for cutting the negative electrode sheet, thereby improving stacking efficiency. Furthermore, the last negative electrode sheet does not require a separate composite buffer, which is beneficial for improving equipment efficiency and quality.

[0055] First Embodiment

[0056] Please refer to Figures 1 to 5This embodiment provides a cell stacking process, which mainly includes the following steps:

[0057] S100: Insert the cut positive electrode sheet between the first separator 201 and the second separator 203 to form a positive electrode composite sheet 225.

[0058] S200: Insert the positive electrode composite sheet 225 between the uncut first negative electrode sheet 205 and the second negative electrode sheet 207.

[0059] S300: A third separator 211 is formed on the side of the first negative electrode 205 away from the positive electrode composite 225, and a fourth separator 213 is formed on the side of the second negative electrode 207 away from the positive electrode composite 225, thus forming a composite electrode.

[0060] S400: Cut composite electrode sheets to form composite unit sheets 220.

[0061] S500: Composite unit cell 220 and cut single positive electrode 107 are alternately stacked to form a battery cell.

[0062] In step S100, the cut positive electrode sheet is conveyed, a first separator 201 is conveyed on one side of the positive electrode sheet, and a second separator 203 is conveyed on the other side. For example, if the positive electrode sheet is in the middle, the first separator 201 is conveyed above the positive electrode sheet, and the second separator 203 is conveyed below the positive electrode sheet. Then, a hot-pressing composite process is used to hot-press the first separator 201, the positive electrode sheet, and the second separator 203 together to form a positive electrode composite sheet 225. It can be understood that, as... Figure 3 The positive electrode composite sheet 225 includes a first separator 201, a second separator 203, and a positive electrode sheet located between the first separator 201 and the second separator 203.

[0063] Combination Figure 2 Because the positive electrode sheet is cut into electrode segments of a certain length during the transportation process, the positive electrode sheet exists in a spaced-out manner between the first separator 201 and the second separator 203, that is, there is a gap 104 between two adjacent positive electrode sheets. Optionally, after the step of inserting the cut positive electrode sheet between the first separator 201 and the second separator 203, the first separator 201 and the second separator 203 at the gap 104 between two adjacent positive electrode sheets are laminated together. The first separator 201 and the second separator 203 can be laminated by hot pressing or adhesive pressing. Laying the first separator 201 and the second separator 203 at the gap 104 can better protect the positive electrode sheet and improve the insulation performance. At the same time, it can avoid contamination of the positive electrode sheet by dust, debris, etc. in the subsequent cutting process, thus improving the electrical quality.

[0064] In this embodiment, the first separator 201, the positive electrode sheet, and the second separator 203 are first hot-pressed together, and then the first separator 201 and the second separator 203 at the interval 104 are laminated together. Of course, in other optional embodiments, the first separator 201 and the second separator 203 at the interval 104 can also be laminated together first, and then the first separator 201, the positive electrode sheet, and the second separator 203 are hot-pressed together.

[0065] Optionally, the positive electrode includes a first positive electrode 101 and a second positive electrode 103. The step of inserting the cut positive electrode between the first separator 201 and the second separator 203 includes: cutting the first positive electrode 101 and the second positive electrode 103 respectively; and alternately inserting the cut first positive electrode 101 and the second positive electrode 103 between the first separator 201 and the second separator 203.

[0066] In this embodiment, a first conveyor line transports a first positive electrode sheet 101, and a positive electrode sheet cutting unit 113 is provided on the first conveyor line to cut the first positive electrode sheet 101 into electrode segments. A second conveyor line transports a second positive electrode sheet 103, and a positive electrode sheet cutting unit 113 is provided on the second conveyor line to cut the second positive electrode sheet 103 into electrode segments. The electrode segments of the first positive electrode sheet 101 and the second positive electrode sheet 103 alternately enter the space between the first separator 201 and the second separator 203. In this way, the first positive electrode sheet 101 and the second positive electrode sheet 103 are transported alternately, which greatly improves the feeding efficiency of the positive electrode sheet and makes full use of the interval time for cutting the positive electrode sheet. It should be noted that, depending on the conveying efficiency of the first separator 201 and the second separator 203, and the overall stacking efficiency, multiple positive electrode sheet conveyor lines can be set according to the actual situation, such as three or four lines, etc., and the positive electrode sheets on multiple conveyor lines alternately enter the space between the first separator 201 and the second separator 203 to improve the overall stacking efficiency.

[0067] In step S200, after forming the positive electrode composite sheet 225, a third conveyor line and a fourth conveyor line are set up. The third conveyor line conveys the first negative electrode sheet 205, and the fourth conveyor line conveys the second negative electrode sheet 207. The third and fourth conveyor lines are respectively located on both sides of the positive electrode composite sheet 225. In this way, the positive electrode composite sheet 225 can be inserted between the first negative electrode sheet 205 and the second negative electrode sheet 207. In this step, the first negative electrode sheet 205 and the second negative electrode sheet 207 are continuously and synchronously input, that is, there is no need to cut the first negative electrode sheet 205 and the second negative electrode sheet 207. The continuous input of the first negative electrode sheet 205 and the second negative electrode sheet 207 can improve the feeding efficiency of the negative electrode sheets, thereby increasing the overall stacking speed.

[0068] In step S300, the step of forming the composite electrode includes: after forming a third separator 211 on the side of the first negative electrode 205 away from the positive electrode composite 225 and forming a fourth separator 213 on the side of the second negative electrode 207 away from the positive electrode composite 225, hot-pressing the third separator 211, the first negative electrode 205, the positive electrode composite 225, the second negative electrode 207 and the fourth separator 213.

[0069] Optionally, a fifth conveying line is provided on the side of the first negative electrode 205 away from the positive electrode composite 225, and the fifth conveying line is used to convey the third separator 211. A sixth conveying line is provided on the side of the second negative electrode 207 away from the positive electrode composite 225, and the sixth conveying line is used to convey the fourth separator 213. The third separator 211, the first negative electrode 205, the positive electrode composite 225, the second negative electrode 207, and the fourth separator 213 are bonded together by hot pressing to form a composite electrode.

[0070] In step S400, the composite electrode sheet is cut using the cutting mechanism 130 to form the composite unit sheet 220. It can be understood that the cutting position is located at the interval 104 between two adjacent positive electrode sheets. The third separator 211, the first negative electrode sheet 205, the first separator 201, the second separator 203, the second negative electrode sheet 207, and the fourth separator 213 are cut. This is easily understood as... Figure 4 The composite unit cell 220 includes a third separator 211, a first negative electrode 205, a first separator 201, a positive electrode, a second separator 203, a second negative electrode 207, and a fourth separator 213 arranged sequentially from top to bottom.

[0071] Optionally, after the step of cutting the composite electrode sheet to form the composite unit sheet 220, the process also includes cleaning the cut surface of the composite electrode sheet, including but not limited to removing dust, iron and static electricity from the cut surface to achieve the cleanliness requirements of the electrode sheet stack.

[0072] Combination Figure 5In step S500, the step of alternately stacking the composite unit sheet 220 and the cut single positive electrode sheet 107 to form a battery cell includes: transferring the composite unit sheet 220 to the stacking stage 160; cutting the third positive electrode sheet 105 to form a single positive electrode sheet 107; and transferring the single positive electrode sheet 107 to the stacking stage 160; wherein the composite unit sheet 220 and the single positive electrode sheet 107 are stacked alternately. Optionally, the cut composite unit sheet 220 can be transferred to the stacking stage 160 by a first robotic arm 141. In this embodiment, the first robotic arm 141 can transfer multiple composite unit sheets 220 at once, and the multiple composite unit sheets 220 are arranged side by side. The positive electrode includes a third positive electrode 105, which is cut to form a single positive electrode 107. The single positive electrode 107 can be transferred to the stacking stage 160 by a second robotic arm 143. The single positive electrode 107 and the composite unit sheet 220 are stacked alternately to achieve cell stacking. It can be understood that the second robotic arm 143 can also transfer one or more single positive electrode sheets 107 at a time, and the number of single positive electrode sheets 107 transferred by the second robotic arm 143 at a time is the same as the number of composite unit sheets 220 transferred by the first robotic arm 141 at a time, to ensure that the transfer speed of the composite unit sheets 220 and the single positive electrode sheets 107 is consistent, so as to improve the stacking efficiency.

[0073] In this embodiment, the number of stacking stages 160 includes two. The first robotic arm 141 can transfer two composite cell wafers 220 at a time and place them on the two stacking stages 160 respectively. The second robotic arm 143 can transfer two single positive electrode sheets 107 at a time and place them on the two stacking stages 160 respectively, with the single positive electrode sheets 107 and composite cell wafers 220 being placed alternately. Of course, in other optional embodiments, the number of stacking stages 160 can be increased, that is, multiple cells can be stacked at once, greatly improving the stacking efficiency.

[0074] In the cell stacking process of this invention, a positive electrode composite sheet 225 is first formed, then the positive electrode composite sheet 225 is inserted between a first negative electrode sheet 205 and a second negative electrode sheet 207. A third separator 211 is formed on the outside of the first negative electrode sheet 205, and a fourth separator 213 is formed on the outside of the second negative electrode sheet 207. The composite electrode sheet is then hot-pressed to form a composite electrode sheet. The composite electrode sheet is cut into composite unit sheets 220. The third positive electrode sheet 105 is cut into single positive electrode sheets 107. The composite unit sheets 220 and single positive electrode sheets 107 are alternately stacked to complete the cell stacking. In this process, the negative electrode sheet does not need to be cut during the composite process, improving the conveying efficiency of the negative electrode sheet. The last negative electrode sheet does not require a separate composite sheet buffer, improving equipment efficiency and quality. During the formation of the positive electrode composite sheet, the first positive electrode sheet 101 and the second positive electrode sheet 103 are alternately conveyed, greatly improving the conveying efficiency of the positive electrode sheet. By bonding a first separator 201 and a second separator 203 at a spacing of 104 between two adjacent positive electrode plates, contamination of the positive electrode plates can be prevented, protecting them and improving insulation performance. This cell stacking process has higher stacking efficiency and better stacking quality.

[0075] Second Embodiment

[0076] Combination Figures 1 to 5 This invention provides a battery cell stacking device 100, including a first composite mechanism 110, a second composite mechanism 120, a cutting mechanism 130, and a stacking mechanism 140. The first composite mechanism 110 is used to form a positive electrode composite sheet 225; the second composite mechanism 120 is used to form a composite electrode sheet; the cutting mechanism 130 is used to cut the composite electrode sheet into composite unit sheets 220; and the stacking mechanism 140 is used to alternately stack the composite unit sheets 220 and the cut single positive electrode sheets 107 onto a stacking stage 160.

[0077] Optionally, the first composite mechanism 110 includes a positive electrode unwinding unit 111, a positive electrode cutting unit 113, a first diaphragm conveying unit 115, a first hot pressing unit 117, and a second hot pressing unit 119 arranged sequentially. The positive electrode unwinding unit 111 includes an unwinding roller and a clamping unit. The positive electrode sheet is unwound from the unwinding roller and conveyed to the clamping unit, which clamps the positive electrode sheet and feeds it, providing the driving force for the movement of the positive electrode sheet. After the positive electrode sheet reaches a preset length, the positive electrode cutting unit 113 cuts the positive electrode sheet.

[0078] The positive electrode unwinding unit 111 includes two units: one for conveying the first positive electrode 101 and the other for conveying the second positive electrode 103. Of course, in other embodiments, the number of positive electrode unwinding units 111 can be three, four, or more. Each positive electrode unwinding unit 111 is matched with one positive electrode cutting unit 113. That is, in this embodiment, there are two positive electrode cutting units 113: one for cutting the first positive electrode 101 and the other for cutting the second positive electrode 103.

[0079] There are two first diaphragm conveying units 115: one located on one side of the positive electrode sheet for conveying the first diaphragm 201, and the other located on the other side for conveying the second diaphragm 203. A positive electrode sheet cutting unit 113 is located between the positive electrode sheet unwinding unit 111 and the first diaphragm conveying unit 115. In this way, the first positive electrode sheet 101 and the second positive electrode sheet 103 are cut and alternately fed between the first diaphragm 201 and the second diaphragm 203, which improves the conveying efficiency of the positive electrode sheet and thus improves the stacking efficiency.

[0080] It is understandable that the positive electrode sheet conveying process includes not only cutting the positive electrode sheet, but also operations such as correction, quality inspection, dust removal, iron removal, and static electricity removal. For example, an upper and lower unwinding clamping and cutting feeding method can be used. The first composite mechanism 110 also includes a process correction unit, a CCD detection unit, and a dust removal unit. The positive electrode sheet unwinding unit 111 is used to feed the positive electrode sheet. The process correction unit is used to correct the deviation of the positive electrode sheet, improving the conveying accuracy and thus improving the stacking accuracy. The positive electrode sheet cutting unit 113 can cut the positive electrode sheet. The CCD detection unit can be used to detect whether the positive electrode sheet meets the stacking requirements and whether there are quality defects. Optionally, the CCD detection unit can also determine whether the positive electrode sheet has directional deviation during conveying, assisting the process correction mechanism in correction. The dust removal unit is used to clean the positive electrode sheet, improving its cleanliness.

[0081] As is easily understood, the process correction unit, positive electrode cutting unit 113, CCD detection unit, and dust removal unit are all located after the positive electrode unwinding unit 111, and their relative positions can be flexibly adjusted according to actual conditions. For example, the positive electrode unwinding unit 111, positive electrode cutting unit 113, CCD detection unit, process correction unit, and dust removal unit can be arranged sequentially.

[0082] Optionally, the first hot-pressing unit 117 includes two opposing first hot-pressing rollers, through which the first diaphragm 201, the second diaphragm 203, and the positive electrode sheet pass. The first hot-pressing rollers apply pressure and heat to the first diaphragm 201, the second diaphragm 203, and the positive electrode sheet, for hot-pressing and bonding them together. Optionally, the first bonding mechanism 110 further includes a limiting component for limiting the first diaphragm 201, the positive electrode sheet, and the second diaphragm 203 during the bonding process. The limiting component includes, but is not limited to, using a limiting roller.

[0083] The second hot-pressing unit 119 is spaced apart from the first hot-pressing unit 117. The second hot-pressing unit 119 includes two opposing adhesive rollers, through which the first diaphragm 201, the second diaphragm 203, and the positive electrode sheet pass. The adhesive rollers are used to bond the first diaphragm 201 and the second diaphragm 203 at the interval 104 between two adjacent positive electrode sheets, including but not limited to hot-press bonding or adhesive bonding. After the first diaphragm 201 and the second diaphragm 203 are bonded, the positive electrode sheet is completely enveloped between the first diaphragm 201 and the second diaphragm 203, providing better protection for the positive electrode sheet and preventing contamination or damage.

[0084] It is understood that the first hot-pressing unit 117 may be located between the second hot-pressing unit 119 and the first diaphragm conveying unit 115, or the second hot-pressing unit 119 may be located between the first hot-pressing unit 117 and the first diaphragm conveying unit 115. No specific limitation is made here.

[0085] The second composite mechanism 120 includes a negative electrode unwinding unit 121, a second diaphragm conveying unit 123, and a third hot-pressing unit 125 arranged sequentially. The negative electrode unwinding unit 121 is located between the second hot-pressing unit 119 and the second diaphragm conveying unit 123. The negative electrode unwinding unit 121 employs an unwinding roller. Two negative electrode unwinding units 121 are included, one for conveying the first negative electrode 205 and the other for conveying the second negative electrode 207. Two second diaphragm conveying units 123 are included, one for conveying the third diaphragm 211 and the other for conveying the fourth diaphragm 213.

[0086] It can be understood that the first negative electrode 205 and the second negative electrode 207 are respectively disposed on both sides of the positive electrode composite sheet 225, that is, the positive electrode composite sheet 225 is input between the first negative electrode 205 and the second negative electrode 207. Of the two second diaphragm delivery units 123, one is disposed on one side of the first negative electrode 205, and the other is disposed on one side of the second negative electrode 207. That is, the third diaphragm 211 is located on the side of the first negative electrode 205 away from the positive electrode composite sheet 225, and the fourth diaphragm 213 is located on the side of the second negative electrode 207 away from the positive electrode composite sheet 225.

[0087] The third hot-pressing unit 125 includes two opposing second hot-pressing rollers. The third diaphragm 211, the first negative electrode 205, the positive electrode composite sheet 225, the second negative electrode 207, and the fourth diaphragm 213 pass between the two second hot-pressing rollers. The second hot-pressing rollers apply pressure and heat to the third diaphragm 211, the first negative electrode 205, the positive electrode composite sheet 225, the second negative electrode 207, and the fourth diaphragm 213 to hot-press and bond them together to form a composite electrode sheet.

[0088] The structure and principle of the third hot-pressing unit 125 are the same as those of the first hot-pressing unit 117, and will not be described again here. The unwinding and conveying of the first negative electrode 205 and the second negative electrode 207 are similar to the unwinding and conveying principles of the positive electrode. The structure and principle of the second diaphragm conveying unit 123 are similar to those of the first diaphragm conveying unit 115. In the second composite mechanism 120, the first negative electrode 205 and the second negative electrode 207 do not need to be cut, and are fed by continuous clamping and feeding.

[0089] It is understood that the second composite mechanism 120 also includes a process correction unit, a CCD detection unit and a dust removal unit located after the negative electrode unwinding unit 121, for correcting the first negative electrode 205, detecting its quality, removing dust, removing iron and removing static electricity, etc.

[0090] The cutting mechanism 130 is located after the third hot-pressing unit 125. That is, after the composite electrode sheet is formed by hot-pressing in the third hot-pressing unit 125, the cutting mechanism 130 cuts the composite electrode sheet into composite unit sheets 220. It can be understood that the cutting mechanism 130 cuts the composite electrode sheet into composite unit sheets 220 at positions corresponding to the interval 104 between two adjacent positive electrode sheets. The cutting mechanism 130 may, but is not limited to, using laser cutting or blade cutting methods. The cutting mechanism 130 may be located on one side of the composite electrode sheet, or simultaneously on both sides of the composite electrode sheet; no specific limitation is made here. In this embodiment, the cutting mechanism 130 uses an infrared laser cutter located on each side of the composite electrode sheet; optionally, the two infrared laser cutters are arranged opposite each other.

[0091] Optionally, the cell stacking device 100 further includes a cleaning unit 150, which is located on the side of the cutting mechanism 130 away from the third hot pressing unit 125. That is, the cleaning unit 150 is located after the cutting mechanism 130 and is used to clean the cutting surface, including but not limited to dust removal, iron removal and static electricity removal, to achieve the cleanliness requirements of electrode stacking.

[0092] It is understandable that the positive electrode composite sheet 225 passes through the negative electrode sheet unwinding unit 121, the second diaphragm conveying unit 123, the third hot pressing unit 125, the cutting mechanism 130 and the cleaning unit 150 in sequence, and then enters the stacking mechanism 140.

[0093] The stacking mechanism 140 includes a first robotic arm 141 and a second robotic arm 143. The cell stacking device 100 also includes a positive electrode sheet conveying mechanism 230, which includes a positive electrode sheet unwinding roller 231 for conveying a third positive electrode sheet 105. A cutting unit 233 is matched on the positive electrode sheet conveying mechanism 230 for cutting the third positive electrode sheet 105 into single positive electrode sheets 107.

[0094] A first robotic arm 141 is positioned after the cleaning unit 150 and is used to transfer the cleaned composite unit to the stacking table 160. A second robotic arm 143 is positioned after the cutting unit 233 and is used to transfer the cut single positive electrode sheet 107 to the stacking table 160, with the composite unit sheet 220 and the single positive electrode sheet 107 placed alternately. In this embodiment, there are two stacking tables 160. The first robotic arm 141 can transfer two composite unit sheets 220 at a time and place them on the two stacking tables 160 respectively. The second robotic arm 143 can transfer two single positive electrode sheets 107 at a time and place them on the two stacking tables 160 respectively, with the single positive electrode sheet 107 and the composite unit sheet 220 placed alternately. Of course, in other optional embodiments, the number of stacking tables 160 can be increased, and the first robotic arm 141 can transfer multiple composite unit sheets 220 at a time and place them on multiple stacking tables 160 respectively. The second robotic arm 143 can transfer multiple single positive electrode plates 107 at once and place them on multiple stacking stages 160. This allows multiple cells to be stacked at once, greatly improving stacking efficiency.

[0095] It should be noted that the first robotic arm 141 and the second robotic arm 143 can use grippers or suction cups to transfer the composite unit sheet 220 and the single positive electrode sheet 107. The stacking mechanism 140 also includes a positioning unit, which can be a CCD camera. The positioning unit is used to photograph the cleaned composite unit sheet 220 to confirm its position before the first robotic arm 141 transfers the composite unit sheet 220 to the stacking stage 160. The positioning unit is also used to photograph the cleaned single positive electrode sheet 107 for quality inspection and position confirmation before the second robotic arm 143 transfers the single positive electrode sheet 107 to the stacking stage 160 where the composite unit sheet 220 is placed.

[0096] It should be understood that the cycle time for clamping and feeding the wafers is 0.4 to 0.6 s / pcs, taking 0.6 s / pcs as an example. The cell stacking process and cell stacking device 100 provided in this embodiment of the invention use alternating feeding of the first positive electrode 101 and the second positive electrode 103, which can increase the feeding speed to twice the original, i.e., the feeding cycle is 0.3 s / pcs. Thus, two feeding cycles can be completed within 0.6 s, i.e., the feeding of two positive electrode assemblies (one first positive electrode 101 and one second positive electrode 103), four negative electrode assemblies, and two third positive electrode assemblies 105. In other words, eight electrode assemblies can be fed within 0.6 s, and the feeding efficiency of a single electrode assembly is 0.6 s / 8 = 0.075 s / pcs. If the cycle time for clamping and feeding the wafer is 0.4s, then the wafer feeding efficiency per single electrode is 0.05s / pcs, and the equipment PPM is 800-1200pcs / min. It can be seen that this significantly improves the wafer feeding efficiency and increases the stacking efficiency.

[0097] Furthermore, by alternating the stacking of composite unit plates 220 and single positive electrode plates 107, the final stacking can be controlled to be composite unit plates 220. This eliminates the need to separately manufacture negative electrode composite plates for the final stacking, further improving the stacking efficiency.

[0098] This invention also provides a battery cell manufactured using the battery cell stacking process described in any of the foregoing embodiments, or using the battery cell stacking apparatus 100 described in any of the foregoing embodiments. This battery cell has high production efficiency and good quality.

[0099] Other parts not mentioned in this embodiment are similar to those described in the first embodiment and will not be repeated here.

[0100] In summary, the cell stacking process, cell stacking device 100, and cell provided by the embodiments of the present invention have the following beneficial effects:

[0101] The battery cell stacking process provided in this embodiment of the invention first forms a positive electrode composite sheet 225, then forms a composite electrode sheet consisting of a positive electrode sheet, a negative electrode sheet, and a separator. The composite electrode sheet is then cut into composite unit sheets 220, and these composite unit sheets 220 are alternately stacked with single positive electrode sheets 107 to form a battery cell. Notably, there is no need to separately cut the negative electrode sheet; the negative electrode sheet is continuously fed in, greatly improving stacking efficiency. Furthermore, using this battery cell stacking process, the last negative electrode sheet does not require a separate composite sheet buffer, which is beneficial for improving equipment efficiency and quality. The alternating feeding of the first positive electrode sheet 101 and the second positive electrode sheet 103 improves the feeding efficiency of the positive electrode sheet. The second hot-pressing unit 119 can combine the first separator 201 and the second separator 203, providing better protection for the positive electrode sheet. The cleaning unit 150 can improve the cleanliness of the composite unit sheets 220, enhancing the stacking quality of the battery cell. This battery cell stacking process offers high production efficiency and good stacking quality.

[0102] The battery cell stacking apparatus 100 provided in this embodiment of the invention uses a first composite mechanism 110 to form a positive electrode composite sheet 225; a second composite mechanism 120 to form a composite electrode sheet; a cutting mechanism 130 to cut the composite electrode sheet into composite unit sheets 220; and a stacking mechanism 140 to alternately stack the composite unit sheets 220 and the cut single positive electrode sheets 107 onto a stacking stage 160 to achieve battery cell stacking with high efficiency. This battery cell stacking apparatus 100 does not require cutting of the negative electrode sheet, and the last negative electrode sheet does not require a separate composite sheet buffer, which helps improve equipment efficiency and quality.

[0103] The battery cell provided in this embodiment of the invention is manufactured using the above-mentioned battery cell stacking process or battery cell stacking device 100, resulting in high battery cell production efficiency and good quality.

[0104] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cell stacking process, characterized in that, include: The cut positive electrode sheet is inserted between the first and second separators to form a positive electrode composite sheet; wherein, there is a gap between two adjacent positive electrode sheets, and the first and second separators at the gap between two adjacent positive electrode sheets are combined together. Insert the positive electrode composite sheet between the uncut first negative electrode sheet and the second negative electrode sheet; A third separator is formed on the side of the first negative electrode sheet away from the positive electrode composite sheet, and a fourth separator is formed on the side of the second negative electrode sheet away from the positive electrode composite sheet. Then, the third separator, the first negative electrode sheet, the positive electrode composite sheet, the second negative electrode sheet and the fourth separator are hot-pressed to form a composite electrode sheet. The composite electrode sheet is cut to form a composite unit sheet; wherein the cutting position is located at the interval between two adjacent positive electrode sheets; The composite unit wafers and cut single positive electrode wafers are alternately stacked to form a battery cell; The positive electrode includes a first positive electrode and a second positive electrode, and the step of inserting the cut positive electrode between the first diaphragm and the second diaphragm includes: Cut the first positive electrode and the second positive electrode separately; The cut first positive electrode and the second positive electrode are alternately inserted between the first diaphragm and the second diaphragm.

2. The cell stacking process according to claim 1, characterized in that, The steps for forming the positive electrode composite sheet include: After the step of inserting the cut positive electrode sheet between the first and second separators, the first separator, the positive electrode sheet, and the second separator are hot-pressed together.

3. The cell stacking process according to claim 1, characterized in that, After the step of cutting the composite electrode sheet to form a composite unit sheet, the process further includes: Clean the cut surfaces of the composite electrode.

4. The cell stacking process according to claim 1, characterized in that, The step of alternately stacking the composite unit wafers and cut single positive electrode sheets to form a battery cell includes: Transfer the composite unit wafer to the stacking stage; Cut the third positive electrode sheet to form a single positive electrode sheet; Transfer a single positive electrode sheet to the stacking stage; wherein the composite unit sheet and the single positive electrode sheet are stacked alternately.

5. A cell stacking device, characterized in that, Suitable for the cell stacking process as described in any one of claims 1 to 4, the cell stacking apparatus comprises: The first composite mechanism is used to form the positive electrode composite sheet; The second composite mechanism is used to form the composite electrode sheet; A cutting mechanism is used to cut the composite electrode sheet into composite unit sheets; The stacking mechanism is used to alternately stack the composite unit sheet and the cut single positive electrode sheet onto the stacking table.

6. The cell stacking device according to claim 5, characterized in that, The first composite mechanism includes a positive electrode unwinding unit, a positive electrode cutting unit, a first diaphragm conveying unit, a first hot pressing unit, and a second hot pressing unit arranged sequentially. The second composite mechanism includes a negative electrode unwinding unit, a second diaphragm conveying unit, and a third hot pressing unit arranged sequentially; the negative electrode unwinding unit is located between the second hot pressing unit and the second diaphragm conveying unit.

7. The cell stacking device according to claim 6, characterized in that, It also includes a cleaning unit located on the side of the cutting mechanism away from the third hot pressing unit.

8. A battery cell, characterized in that, It is manufactured using the cell stacking process as described in any one of claims 1 to 4, or using the cell stacking apparatus as described in any one of claims 5 to 7.

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