Pole piece folding control method and apparatus, pole piece folding apparatus, and battery production system

Abstract

The present application relates to a pole piece folding control method and apparatus, a pole piece folding apparatus, and a battery production system. During the folding process of a pole piece group, a conveying component is controlled to operate, and the pole piece group is driven to move towards a stacking platform. When a lamination area on the stacking platform starts to fold or has been folded, at least one of the conveying component and the stacking platform is controlled to move such that the distance between a conveying end of the conveying component and at least part of an operating surface of the stacking platform is pulled open. In this way, a clearance space can be provided for folding of the lamination area, thereby facilitating stress relief of the lamination area during folding, reducing a pulling force of the lamination area in a folded state on a non-folded lamination area, and reducing a degree of bending and warping of the lamination area at a folding position. Thus, the probability of abnormal gaps being generated at the folding position of a laminated structure is reduced, thereby effectively reducing the probability of lithium deposition at the folding position of the electrode, and improving the quality of the laminated battery.

Description

Pole piece folding control method, device, pole piece folding device and battery production system

[0001] Cross-references

[0002] This application refers to Chinese Patent Application No. 2023111689854 filed on September 12, 2023, entitled “Pole Folding Control Method, Device, Pole Folding Device and Battery Production System,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to the field of battery production technology, and in particular to a pole piece folding control method and device, a pole piece folding device, and a battery production system. Background Art

[0004] The electrode assembly is the component in a battery where the electrochemical reaction occurs. It is primarily composed of a wound or stacked positive and negative electrode sheets, typically with a separator between them. During the stacking process, the stacked negative, separator, and positive electrode sheets are folded. However, due to limitations in traditional electrode folding methods, lithium deposition can easily occur at the folded area, affecting the quality of the stacked battery.

[0005] Summary of the Invention

[0006] Based on this, it is necessary to provide a pole piece folding control method, device, pole piece folding device and battery production system to reduce the probability of lithium deposition at the folding part of the pole piece and improve the quality of the stacked battery.

[0007] In the first aspect, the present application provides a pole piece folding control method, wherein the pole piece folding mechanism includes a stacking platform and a conveying component for conveying a pole piece group, wherein the pole piece group has a plurality of stacking areas along its own length direction; the pole piece folding control method includes the following steps: controlling the conveying component to drive the pole piece group to be conveyed toward the stacking platform; in response to the stacking area folding on the stacking platform, controlling the conveying component and / or the stacking platform to move so that the connecting distance between the conveying end of the conveying component acting on the pole piece group and at least part of the working surface of the stacking platform is increased.

[0008] The above-mentioned electrode folding control method controls the operation of the conveying component to drive the electrode group toward the stacking platform during the folding process of the electrode group. When a laminated area on the stacking platform begins to fold or has already folded, at least one of the conveying component and the stacking platform is controlled to move so that the distance between the conveying end of the conveying component and at least part of the working surface of the stacking platform is widened. This can provide space for the folding of the laminated area, facilitate its stress release during folding, reduce the pulling force of the laminated area in the folding state on the laminated area that has not yet folded, and reduce the degree of bending and warping of the laminated area at the folding. At this time, the probability of the laminate structure forming a gap abnormality at the folding is reduced, thereby effectively reducing the probability of lithium deposition at the folding of the electrode, and improving the quality of the laminated battery.

[0009] In some embodiments, the step of controlling the movement of the conveying component and / or the stacking platform includes: controlling the conveying component and / or the stacking platform to continuously and periodically execute a movement strategy in a preset direction, wherein the movement strategy includes driving at least one of the conveying component and the stacking platform to move in a direction away from each other; and driving at least one of the conveying component and the stacking platform to move in a direction toward each other, wherein the preset direction is the direction of the distance between the conveying component and the stacking platform. With this design, during the folding process of the electrode assembly, controlling at least one of the conveying component and the stacking platform to periodically execute the movement strategy provides effective clearance for the folding process of the stacking area, facilitates the release of force on the stacking area, reduces the degree of bending and warping in the stacking area, and improves the quality of the laminated battery.

[0010] In some embodiments, the step of executing the movement strategy includes: controlling the amount of movement of at least one of the conveying component and the stacking platform in a direction away from each other to be a first displacement; and controlling the amount of movement of at least one of the conveying component and the stacking platform in a direction toward each other to be a second displacement, wherein the second displacement is less than or equal to the first displacement. In this way, when executing the movement strategy, the amount of movement of the conveying component or the stacking platform in the direction toward each other is controlled to at least not exceed the amount of movement of the conveying component or the stacking platform in the direction away from each other. Under the premise of reducing the degree of bending of the electrode assembly at the folding point, the spacing between the conveying component and the stacking platform is maintained or increased, which is conducive to the stable folding operation of the electrode assembly to a certain extent.

[0011] In some embodiments, the first displacement is greater than the second displacement, and the difference between the first displacement and the second displacement is denoted as ΔW. The thickness of the electrode assembly in the lamination area is denoted as h, where 1≤ΔW / h≤5. Thus, by controlling the value of ΔW / h between 1 and 5, sufficient space is maintained between the conveying member and the stacking platform after each folding, facilitating stable folding of the electrode assembly on the stacking platform and improving the stability of the folding process.

[0012] In some embodiments, ΔW / h further satisfies the condition: 2≤ΔW / h≤3. Thus, by further controlling the value of ΔW / h to be between 2 and 3, the space between the conveying component and the stacking table can be more reasonably controlled after each folding, thereby making the folding process of the electrode assembly on the stacking table more stable.

[0013] In some embodiments, after controlling the movement of at least one of the conveying member and the stacking platform in a direction toward each other to a second displacement, the method further includes: if the first displacement is equal to the second displacement, in response to each execution of at least one movement strategy, controlling the conveying member and / or the stacking platform to move away from each other by a predetermined displacement. This effectively compensates for the space compressed by the increased number of folding times, facilitating the folding of the electrode assembly; it also facilitates stress release during the folding process, thereby improving the quality of the laminated battery.

[0014] In some embodiments, the ratio of the preset displacement to the thickness of the electrode group in the lamination area is denoted as α, where 1≤α≤5. Thus, controlling the ratio of the preset displacement to the thickness of the electrode group in the lamination area to be between 1 and 5 facilitates appropriate displacement of the conveying member or the stacking platform after folding, leaving a reasonable space between the conveying member and the stacking platform for the electrode group, thereby achieving a stable and efficient folding process.

[0015] In some embodiments, α further satisfies the condition: 2≤α≤3. Thus, the value of α is further controlled between 2 and 3, so that after each folding, the space between the conveying component and the stacking table is more reasonably controlled, thereby making the folding process of the electrode assembly on the stacking table more stable.

[0016] In some embodiments, when at least one of the conveying member and the stacking platform moves a first displacement in a direction away from each other, the conveying end of the conveying member is controlled to move the electrode stack toward the stacking platform by a third displacement, wherein the third displacement is greater than the first displacement. Thus, by controlling the third displacement to be greater than the first displacement, the excess conveying force can drive the stacking area to continue folding on the stacking platform, thereby increasing the space between the conveying member and the stacking platform to relieve stress and allowing the electrode stack to continue folding stably.

[0017] In some embodiments, the ratio of the third displacement to the length of the stacking area is denoted as η, where 0.3 ≤ η ≤ 0.7. Thus, by controlling the ratio of the third displacement to the length of the stacking area to be between 0.3 and 0.7, the electrode assembly is transported by at least 0.3 of the stacking area when the conveying component or stacking platform completes the first stage of the movement strategy. This helps to reduce bending and warping of the electrode assembly at the folding point and improve the quality of the laminated battery.

[0018] In some embodiments, η further satisfies the condition: 0.45≤η≤0.55. Thus, further controlling the ratio of the third displacement to the length of the laminated region to be between 0.45 and 0.55 facilitates further effective control of the electrode assembly folding process, thereby improving the controllability of the laminated battery quality.

[0019] In some embodiments, the ratio of the first displacement to the length of the laminated area is denoted as λ, where 0.1≤λ≤0.6. Thus, controlling the ratio of the first displacement to the length of the laminated area to be between 0.1 and 0.6 effectively balances stress release during the folding process with folding efficiency.

[0020] In some embodiments, λ further satisfies the condition: 0.4≤λ≤0.5. In this way, the ratio of the first displacement to the length of the lamination area is further controlled between 0.4 and 0.5, facilitating more precise control of the folding process of the pole piece assembly.

[0021] In some embodiments, after executing the movement strategy, the conveying end of the conveyor component moves the electrode stack in the direction toward the stacking table by at least the length of the stacking area. Thus, linking the movement strategy cycle with the conveyor component's conveying cycle allows for more controllable folding quality of the electrode stack and improved product consistency.

[0022] In some embodiments, before controlling the movement of the conveying member and / or the stacking platform, the step further includes: controlling the minimum distance between the conveying end of the conveying member and the working surface of the stacking platform to be an initial distance, wherein the ratio of the initial distance to the length of the stacking area is denoted as γ, and 1.2≤γ≤2. Thus, controlling the ratio of the initial distance to the length of the stacking area to be between 1.2 and 2 allows a suspended stacking area to be provided between the conveying member and the stacking platform, thereby stabilizing the folding process and improving folding efficiency.

[0023] In some embodiments, γ further satisfies the condition: 1.3≤γ≤1.6. Thus, the ratio of the initial spacing to the length of the lamination area is further controlled between 1.3 and 1.6, facilitating more precise control of the folding of the electrode assembly and further improving the stability and efficiency of the folding process.

[0024] In some embodiments, in response to the step of folding the laminated area on the stacking platform, the method includes controlling the conveying displacement of the conveying end of the conveying component relative to the electrode group in a direction toward one side of the stacking platform to be a fourth displacement, wherein the ratio of the fourth displacement to the length of the laminated area is denoted as ε, and 2≤ε≤10. In this way, by controlling the ratio of the conveying displacement of the electrode group by the conveying end of the conveying component to the length of the laminated area to be between 2 and 10, at least one laminated area is already folded on the stacking platform, facilitating stress relief for the laminated area being folded, reducing bending and warping at the folded area, and improving the quality of the laminated battery.

[0025] In some embodiments, ε also satisfies the condition: 2.1≤ε≤2.9. Thus, the ratio of the conveying displacement of the conveying end of the conveying component to the electrode assembly to the length of the lamination area is further controlled to be between 2.1 and 2.9, thereby reducing the number of folds of the lamination area on the lamination table before the movement strategy is executed. This allows the movement strategy to improve most of the folding process of the electrode assembly, further improving the quality of the laminated battery.

[0026] In the second aspect, the present application provides a pole piece folding control device, which adopts any of the above pole piece folding control methods. The pole piece folding control device includes: a response module, which is used to determine whether the stacking area is folded on the stacking table; an execution module, which is used to control the operation of the conveying component and can control the conveying component and / or the stacking table movement according to the signal feedback from the response module.

[0027] On the third aspect, the present application provides a pole piece folding device, which adopts any of the above pole piece folding control methods, and the pole piece folding device includes: a pole piece folding mechanism, including a stacking table and a conveying component for conveying the pole piece group and folding the pole piece group back and forth on the stacking table; a driving mechanism for driving the conveying component and / or the stacking table to move.

[0028] In some embodiments, the conveying components and the stacking platform are spaced apart along a predetermined direction, and a drive mechanism is used to drive at least one of the conveying components and the stacking platform to reciprocate in the predetermined direction. Thus, by using the drive mechanism to drive the conveying components and / or the stacking platform to reciprocate in the predetermined direction, the distance between the conveying components and the stacking platform is increased during the folding process, providing effective clearance for the folding process of the stacking area, facilitating the release of forces on the stacking area, reducing the degree of warping in the stacking area, and improving the quality of the stacked battery.

[0029] In a fourth aspect, the present application provides a battery production system, which includes the above-mentioned electrode folding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive work. In the drawings:

[0031] FIG1 is a flow chart of a pole piece folding control method according to some embodiments of the present application.

[0032] FIG2 is a schematic structural diagram of the electrode assembly during the folding process described in some embodiments of the present application.

[0033] FIG3 is a schematic diagram of a structure in which a pole piece assembly described in some embodiments of the present application is bent at a fold.

[0034] FIG4 is a schematic diagram of the gap structure at the folding portion of the laminate structure described in some embodiments of the present application.

[0035] FIG5 is a second flow chart of the pole piece folding control method described in some embodiments of the present application.

[0036] Figure 6 is a structural schematic diagram of the folding process of the electrode group described in some embodiments of the present application, and (a) to (c) in Figure 6 are structural schematic diagrams corresponding to different stages of the folding process of the electrode group described in some embodiments of the present application.

[0037] FIG7 is a third flow chart of the pole piece folding control method described in some embodiments of the present application.

[0038] FIG8 is a graph showing specific motion position amplitudes of the stacking stage described in some embodiments of the present application.

[0039] FIG9 is a fourth flow chart of the pole piece folding control method described in some embodiments of the present application.

[0040] Figure 10 is a structural schematic diagram of the folding process of the electrode group described in other embodiments of the present application, and (a) to (d) in Figure 10 are structural schematic diagrams corresponding to different stages of the folding process of the electrode group described in other embodiments of the present application.

[0041] FIG11 is a schematic structural diagram of the pole piece group in the pole piece folding mechanism before executing the movement strategy described in some embodiments of the present application.

[0042] FIG12 is a schematic diagram of the structure of a pole piece folding control device described in some embodiments of the present application. 100, pole piece folding device; 10, pole piece folding mechanism; 1a, first displacement; 1b, second displacement; 1c, third displacement; 1d, preset displacement; 1e, initial spacing; 1f, gap; 11, conveying component; 111, first roller; 112, second roller; 113, conveying end; 12, stacking platform; 121, working surface; 20, pole piece group; 21, stacking area; 22, first pole piece; 23, second pole piece; 24, diaphragm; 25, folding area; 30, driving mechanism; X, preset direction; 200, response module; 300, execution module. DETAILED DESCRIPTION

[0043] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0044] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0045] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0046] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0047] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0048] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0049] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0050] In a battery, the electrode assembly, which is the component where the electrochemical reaction occurs, is typically formed by stacking a positive electrode, a separator, and a negative electrode. During the stacking process, the electrode assembly formed by the stacked negative electrode, separator, and positive electrode can be folded in a Z-shaped structure. For example, one stacking area on the electrode assembly is folded in a right-bending direction on a stacking table. After folding, the connected stacking area is folded in a left-bending direction. This cycle continues to form a Z-shaped stacking structure. Stacked batteries formed using traditional folding methods generally experience lithium deposition at the folding point of the electrode, resulting in reduced quality of the stacked battery.

[0051] Based on this, in order to effectively improve the problem that the laminated structure formed by the traditional folding method is prone to lithium deposition at the folding part, the present application provides a method for controlling the folding of the electrode group. During the folding process of the electrode group, the conveying component is controlled to work and drive the electrode group to move toward the stacking platform. When a laminated area on the stacking platform begins to or has already been folded, at least one of the conveying component and the stacking platform is controlled to move so that the distance between the conveying end of the conveying component and at least part of the working surface of the stacking platform is widened. This can provide space for the folding of the laminated area, facilitate its stress release during folding, reduce the pulling force of the laminated area in the folding state on the laminated area that has not yet folded, and reduce the degree of bending and warping of the laminated area at the folding part. At this time, the probability of the laminated structure generating gap abnormalities at the folding part is reduced, thereby effectively reducing the probability of lithium deposition at the folding part of the electrode, and improving the quality of the laminated battery.

[0052] In some embodiments of the present application, the electrode assembly is a component in the battery where an electrochemical reaction occurs, which can be formed by stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0053] According to some embodiments of the present application, referring to FIG. 1 and FIG. 2 , the present application provides a method for controlling electrode folding. The electrode folding mechanism 10 includes a stacking platform 12 and a conveying component 11 for conveying an electrode assembly 20. The electrode assembly 20 has a plurality of stacking areas 21 along its length. The electrode folding control method includes the following steps:

[0054] S100, controlling the conveying component 11 to drive the electrode group 20 to be conveyed toward the stacking table 12;

[0055] S200, in response to the lamination area 21 folding on the stacking platform 12, control the conveying component 11 and / or the stacking platform 12 to move so that the connecting distance between the conveying end 113 of the conveying component 11 acting on the pole piece group 20 and at least a part of the working surface 121 of the stacking platform 12 is increased.

[0056] The electrode folding mechanism 10 refers to a device that can fold the electrode group 20 back and forth in a Z-shape on the stacking platform 12; and the electrode group 20 refers to a combined structure formed by the first electrode 22, the diaphragm 24 and the second electrode 23. In order to ensure that the electrode group 20 can be continuously folded back and forth in a Z-shape to form a laminated structure, the electrode group 20 has a number of continuous and foldable laminated areas 21 along its own length direction, and there is a fold between two adjacent laminated areas 21. Among them, the fold can be set on one side of the electrode group 20, or on two opposite sides of the electrode group 20, that is, double-sided marking. Of course, the concept of the laminated area 21 can also be defined by the fold on the electrode group 20, for example: along the length direction of the electrode group 20, the area between two adjacent folds is the laminated area 21. In addition, it needs to be explained that the folding of the laminated area 21 is actually the folding of the corresponding part of the electrode group 20 in the laminated area 21. For the sake of convenience, it is abbreviated as the folding of the laminated area 21 in the whole text.

[0057] To allow each laminated area 21 to fold back and forth (also understood as folding left and right), the first electrode sheet 22 and the diaphragm 24 can be designed as a continuous strip structure. The second electrode sheet 23 can be die-cut into a structure of the required size and placed one-to-one in each laminated area 21. Furthermore, in two adjacent laminated areas 21, the two second electrode sheets 23 are located on different sides of the electrode assembly 20. The first electrode sheet 22 can be a negative electrode sheet, and the second electrode sheet 23 can be a positive electrode sheet.

[0058] The conveying component 11 refers to a device that provides conveying power for the electrode group 20, which can be a roller structure. For example, the conveying component 11 can include a first roller 111 and a second roller 112 that cooperate with each other, and the electrode group 20 is clamped between the first roller 111 and the second roller 112. At this time, the conveying end 113 of the conveying component 11 acting on the electrode group 20 can be understood as the end of the first roller 111 or the second roller 112 that contacts the electrode group 20. Of course, in some embodiments, the conveying end 113 of the conveying component 11 can also be determined by connecting the center of the circle between the first roller 111 and the second roller 112. The intersection of the connecting line and the first roller 111 or the second roller 112 can also be regarded as the conveying end 113 of the conveying component 11.

[0059] The stacking platform 12 refers to a structure used to support the stacking structure and provide support force for the folding process. For example, during the folding process, the conveying component 11 moves the electrode group 20 toward the stacking platform 12, so that one end of the stacking area 21 contacts the working surface 121 of the stacking platform 12; as the conveying continues, one end of the stacking area 21 gradually bends and fits toward the working surface 121 with the contact point on the working surface 121 as the inflection point.

[0060] When one end of the laminate area 21 is folded with the contact point as the inflection point, one end of the laminate area 21 will be subjected to a pulling force on the stacking platform 12, which will cause the end of the laminate area 21 adjacent thereto to bend and warp. For example: In some embodiments, please refer to FIG3 , when a laminate area 21 is folded, the laminate area 21 will be subjected to a pulling force at the folding point 25, and the pulling force is transmitted to the laminate area 21 adjacent thereto through the laminate area 21, causing one end of the laminate area 21 that has not been folded to bend. The laminate structure formed in this way will bend and warp at the bend. The bending and warping will cause the gap 1f between the two adjacent folds 25 to be abnormal. For example, if the gap 1f is too large, please refer to FIG4 for details, resulting in poor electrolyte wettability and weak lithium ion kinetics, which will make lithium deposition at the folding point 25 easy.

[0061] At this time, if the distance between at least a portion of the working surface 121 and the conveying end 113 of the conveying component 11 is increased, the pulling force of the working surface 121 on the laminated area 21 will be weakened, and the degree of bending and warping of the adjacent and unfolded laminated area 21 will also be reduced.

[0062] In step S200, when at least one of the conveying member 11 and the stacking platform 12 is driven to move, it is determined whether a laminated area 21 is being folded on the stacking platform 12. If no laminated area 21 is being folded, bending of one end of the laminated area 21 will not occur, and there is no need to drive the conveying member 11 and / or the stacking platform 12 to move.

[0063] To reduce the degree of warping of the laminated area 21 at the fold 25, the conveying member 11 or the stacking platform 12 can be moved in various ways, such as: reciprocating vertical movement of the conveying member 11 or the stacking platform 12; rotation of the conveying member 11 or the stacking platform 12 about their respective axes; or horizontal translation of the conveying member 11 or the stacking platform 12. Of course, both components can also move simultaneously, but their respective movement methods can be different, for example: the conveying member 11 can move vertically, and the stacking platform 12 can translate horizontally.

[0064] In addition, the distance between the conveying end 113 of the conveying component 11 and at least a part of the working surface 121 of the stacking platform 12 increases, which can be understood as: the distance between the conveying end 113 of the conveying component 11 and at least a part of the working surface 121 will increase, for example: when the stacking platform 12 moves up and down, the distance between the conveying end 113 of the conveying component 11 and any point on the working surface 121 of the stacking platform 12 will increase; when the stacking platform 12 rotates around its own axis, the distance between the conveying end 113 of the conveying component 11 and the axis center of the stacking platform 12 remains unchanged, but the distance between the conveying end 113 and the part outside the axis center may increase, etc.

[0065] It should be noted that in the embodiments of the present application, "increase in the line distance" does not mean that the line distance increases continuously during the movement of the conveying component 11 or the stacking platform 12. Rather, as the conveying component 11 or the stacking platform 12 moves, the line distance between the conveying end 113 of the conveying component 11 and at least a portion of the working surface 121 of the stacking platform 12 increases over a period of time. For example, as the conveying component 11 or the stacking platform 12 moves, the line distance between the conveying end 113 of the conveying component 11 and at least a portion of the working surface 121 of the stacking platform 12 may periodically increase and then decrease. For ease of understanding, the line distance can be referred to as the distance represented by P in FIG. 2 .

[0066] This design provides space for the folding of the laminated area 21, facilitating stress release during folding, reducing the pulling force exerted by the folding laminated area 21 on the unfolded laminated area 21, and minimizing the degree of bending and warping of the laminated area 21 at the fold 25. This reduces the probability of an abnormal gap 1f forming at the fold 25 of the laminated structure, effectively reducing the probability of lithium deposition at the fold 25, and improving the quality of the laminated battery.

[0067] According to some embodiments of the present application, referring to FIG. 5 , S200 , the step of controlling the movement of the conveying component 11 and / or the stacking platform 12 , includes:

[0068] S210, control the conveying component 11 and / or the stacking platform 12 to continuously and periodically execute a movement strategy in a preset direction X, wherein the movement strategy includes driving at least one of the conveying component 11 and the stacking platform 12 to move in a direction away from each other; driving at least one of the conveying component 11 and the stacking platform 12 to move in a direction close to each other, wherein the preset direction X is the direction of the interval between the conveying component 11 and the stacking platform 12.

[0069] Continuously and periodically executing the movement strategy means that when the conveying component 11 or the stacking platform 12 completes one movement strategy, it immediately executes another movement strategy, and the cycle repeats.

[0070] The movement strategy means that within a cycle, the conveyor unit 11 or the stacking platform 12 first moves away from each other in a preset direction X, and then moves toward each other. "Moving away from each other" refers to the conveyor unit 11 and stacking platform 12 moving away from each other, while "moving toward each other" refers to the conveyor unit 11 and stacking platform 12 moving toward each other.

[0071] It should be explained that controlling the "conveying component 11 and / or the stacking platform 12" to execute the movement strategy can be understood as follows: if one of the conveying component 11 and the stacking platform 12 executes the movement strategy, then the two "at least one of the conveying component 11 and the stacking platform 12" before and after in the movement strategy both refer to the conveying component 11 or the stacking platform 12. If both the conveying component 11 and the stacking platform 12 participate in the execution of the movement strategy, then the two "at least one of the conveying component 11 and the stacking platform 12" before and after in the movement strategy can be both the conveying component 11 and the stacking platform 12, or can be different objects in the conveying component 11 and the stacking platform 12 respectively. For example: in the same movement strategy, after the conveying component 11 moves in a direction away from each other, the stacking platform 12 can move in a direction toward each other; or, after the stacking platform 12 moves in a direction away from each other, the conveying component 11 can move in a direction toward each other, etc.

[0072] When the laminated area 21 is folded on the stacking platform 12, please refer to Figure 6. (a) in Figure 6 is a structural schematic diagram corresponding to the electrode group described in some embodiments of the present application when the stacking platform does not execute the movement strategy during the folding process; (b) in Figure 6 is a structural schematic diagram corresponding to the electrode group described in some embodiments of the present application when the stacking platform moves downward for the first displacement during the folding process; (c) in Figure 6 is a structural schematic diagram corresponding to the electrode group described in some embodiments of the present application when the stacking platform moves upward for the second displacement during the folding process. First, the conveying component 11 or the stacking platform 12 is moved in the preset direction X to open the distance between the conveying component 11 and the stacking platform 12, providing space for the folding of the laminated area 21, facilitating the release of the pulling force on the laminated area 21, and reducing the degree of bending and warping at one end of the laminated area 21. Then, the conveying component 11 or the stacking platform 12 is driven to move in the opposite direction, that is, in the direction of moving closer to each other, so that the laminated area 21 is completely folded on the stacking platform 12.

[0073] To further improve the folding effect, the movement strategy can be executed when the stacking section 21 begins to fold on the stacking platform 12, or when the previous stacking section 21 has just completed folding. The movement strategy can also be terminated when the stacking section 21 is completely folded on the stacking platform 12.

[0074] With such a design, during the folding process of the electrode group 20, at least one of the conveying component 11 and the stacking platform 12 is controlled to periodically execute a movement strategy, providing effective clearance space for the folding process of the stacking area 21, facilitating the release of the force on the stacking area 21, reducing the degree of bending and warping on the stacking area 21, and improving the quality of the stacked battery.

[0075] According to some embodiments of the present application, referring to FIG. 7 , S210, in the step of executing the mobility strategy, includes:

[0076] S211, controlling the movement amount of at least one of the conveying component 11 and the stacking stage 12 in the direction away from each other to be a first displacement 1a;

[0077] S212 , controlling the movement amount of at least one of the conveying component 11 and the stacking platform 12 in the direction of approaching each other to be a second displacement 1 b , wherein the second displacement 1 b is less than or equal to the first displacement 1 a .

[0078] When the second displacement 1b is less than the first displacement 1a, it indicates that the position of the conveyor 11 or stacking platform 12 is not the same after each execution of the movement strategy. For ease of understanding, using Figure 6 as an example, stacking platform 12 is controlled to periodically execute the movement strategy, and stacking platform 12 is located below the conveyor 11. During the folding process, the position of stacking platform 12 moves downward from the first position to the second position, and then moves upward from the second position to the third position, which is now lower than the original first position. This cycle repeats, and the position of stacking platform 12 gradually moves downward after each execution of the movement strategy.

[0079] To facilitate an intuitive understanding of the movement trajectory of the stacking platform 12, the value of the first displacement 1a can be assigned to 1. The specific motion position amplitude curve of the stacking platform 12 at this time can be found in Figure 8. Considering that as folding continues, the number of stacking areas 21 stacked on the stacking platform 12 increases, and the spacing between the stacking platform 12 and the conveying component 11 also decreases, the folding space provided for the stacking areas 21 is gradually compressed. To this end, in this embodiment, the second displacement 1b is controlled to be smaller than the first displacement 1a, which can increase the spacing between the conveying component 11 and the stacking platform 12, thereby partially or completely compensating for the space between the conveying component 11 and the stacking platform 12 that is compressed due to the increased folding thickness, thereby ensuring stable operation of the folding process.

[0080] When the second displacement 1b is equal to the first displacement 1a, it indicates that the conveyor member 11 or the stacking platform 12 remains in the same position after each execution of the movement strategy. To address the situation where the folding space between the conveyor member 11 and the stacking platform 12 decreases due to an increase in the number of stacked lamination areas 21, the conveyor member 11 or the stacking platform 12 can be controlled to move as a whole after the movement strategy is executed to increase the space between them.

[0081] It should be noted that controlling the movement amount of at least one of the conveying component 11 and the stacking platform 12 in the direction away from each other to be the first displacement 1a means: if one of the conveying component 11 and the stacking platform 12 is controlled to move in the direction away from each other, the movement amount of the conveying component 11 or the stacking platform 12 is the first displacement 1a; if both the conveying component 11 and the stacking platform 12 are controlled to move in the direction away from each other, the sum of the movement amounts of the conveying component 11 and the stacking platform 12 is the first displacement 1a.

[0082] Similarly, controlling the movement amount of at least one of the conveying component 11 and the stacking platform 12 in the direction of approaching each other to be the second displacement 1b should be understood as: if one of the conveying component 11 and the stacking platform 12 is controlled to move in the direction of approaching each other, the movement amount of the conveying component 11 or the stacking platform 12 is the second displacement 1b; if both the conveying component 11 and the stacking platform 12 are controlled to move in the direction of approaching each other, the sum of the movement amounts of the conveying component 11 and the stacking platform 12 is the second displacement 1b.

[0083] When executing the movement strategy, the movement amount of the conveying component 11 or the stacking platform 12 in the direction of approaching each other is controlled to at least not exceed the movement amount of the conveying component 11 or the stacking platform 12 in the direction of moving away from each other. On the premise of reducing the degree of bending of the electrode group 20 at the folding part 25, the distance between the conveying component 11 and the stacking platform 12 is kept unchanged or increased, which is beneficial to the stable folding operation of the electrode group 20 to a certain extent.

[0084] According to some embodiments of the present application, please refer to Figure 6, the first displacement 1a is greater than the second displacement 1b, and the difference between the two is recorded as ΔW, and the thickness of the pole piece group 20 in the lamination area 21 is recorded as h, where 1≤ΔW / h≤5.

[0085] The first displacement 1a is greater than the second displacement 1b, indicating that the positions of the conveyor member 11 and the stacking platform 12 are different after each execution of the movement strategy. Furthermore, the spacing between the conveyor member 11 and the stacking platform 12 increases with the number of executions of the movement strategy. This effectively solves the problem of the space between the conveyor member 11 and the stacking platform 12 being compressed due to the increase in the number of folding operations.

[0086] The thickness of the electrode assembly 20 in the laminated region 21 refers to the sum of the thicknesses of the first electrode 22, the second electrode 23, and the separator 24 in the laminated region 21. The thickness of the electrode assembly 20 in the laminated region 21 can be determined based on the actual structural design of the laminated region 21. For example, in the laminated region 21, the electrode assembly 20 can include a first electrode 22, separators 24 disposed on two opposite sides of the first electrode 22, and a second electrode 23 disposed on one of the separators 24. In this case, the thickness of the electrode assembly 20 in the laminated region 21 can be the sum of the thicknesses of the first electrode 22, the second electrode 23, and the two separators 24.

[0087] ΔW / h can take a value between 1 and 5. For example, the value of ΔW / h can be, but is not limited to, 1, 2, 3, 4, 5, etc.

[0088] In addition, when ΔW / h takes a value of 1, it means that the position of the conveying component 11 or the stacking platform 12 after executing the movement strategy is relatively moved back by the thickness of one electrode group 20. If, after executing the movement strategy, there is exactly a laminated area 21 superimposed on the stacking platform 12, the space between the stacking platform 12 and the conveying component 11 that is shortened due to the laminated area 21 superimposed on the stacking platform 12 can be exactly compensated. Similarly, when ΔW / h takes a value of n (n can be 2-5), it means that the position of the conveying component 11 or the stacking platform 12 after executing the movement strategy is relatively moved back by the thickness of n electrode groups 20.

[0089] The value of ΔW / h is controlled between 1 and 5, so that after each folding, sufficient space is maintained between the conveying component 11 and the stacking platform 12, which facilitates the stable folding of the electrode group 20 on the stacking platform 12 and improves the stability of the folding process.

[0090] According to some embodiments of the present application, ΔW / h further satisfies the condition: 2≤ΔW / h≤3.

[0091] ΔW / h can take a value between 2 and 3, for example, the value of ΔW / h can be, but is not limited to, 2, 2.2, 2.4, 2.6, 2.8, 3, etc.

[0092] The value of ΔW / h is further controlled between 2 and 3, so that after each folding, the space between the conveying component 11 and the stacking platform 12 is more reasonably controlled, thereby making the folding process of the electrode group 20 on the stacking platform 12 more stable.

[0093] According to some embodiments of the present application, please refer to Figures 9 and 10. Figure 10 (a) is a structural schematic diagram corresponding to the electrode group described in other embodiments of the present application when the stacking platform does not execute the movement strategy during the folding process; Figure 10 (b) is a structural schematic diagram corresponding to the electrode group described in other embodiments of the present application when the stacking platform moves down a first displacement during the folding process; Figure 10 (c) is a structural schematic diagram corresponding to the electrode group described in other embodiments of the present application when the stacking platform moves up a second displacement during the folding process; Figure 10 (d) is a structural schematic diagram corresponding to the electrode group described in other embodiments of the present application when the stacking platform moves down a preset displacement during the folding process. S212, after the step of controlling the movement amount of at least one of the conveying component 11 and the stacking platform 12 in the direction of approaching each other to be the second displacement 1b, it includes:

[0094] S213 , if the first displacement 1 a is equal to the second displacement 1 b , in response to at least one execution of the movement strategy, controlling the conveying component 11 and / or the stacking platform 12 to move away from each other by a preset displacement amount 1 d .

[0095] The first displacement 1a and the second displacement 1b are equal, indicating that the position of the conveying member 11 or the stacking platform 12 remains unchanged after each execution of the movement strategy. However, as the number of folding increases, the accumulated lamination area 21 on the stacking platform 12 compresses the space between the stacking platform 12 and the conveying member 11, making it difficult to fold the electrode assembly 20 on the stacking platform 12. This also affects the stress release of the lamination area 21 during the folding process.

[0096] To this end, after the conveying component 11 or the stacking platform 12 executes at least one movement strategy, the conveying component 11 or the stacking platform 12 is controlled to move in a direction away from each other. Specifically, the conveying component 11 or the stacking platform 12 may be controlled to move in a direction away from each other after each movement strategy is executed once, or after each movement strategy is executed multiple times. Specifically, in some embodiments, after the conveying component 11 or the stacking platform 12 executes a movement strategy once, the conveying component 11 or the stacking platform 12 is controlled to move in a direction away from each other.

[0097] It should be noted that controlling the conveying component 11 and / or the stacking platform 12 to move in a direction away from each other by a preset displacement amount 1d means: if one of the conveying component 11 and the stacking platform 12 is controlled to move in a direction away from each other, the movement amount of the conveying component 11 or the stacking platform 12 is the preset displacement amount 1d; if both the conveying component 11 and the stacking platform 12 are controlled to move in a direction away from each other, the sum of the movement amounts of the conveying component 11 and the stacking platform 12 is the preset displacement amount 1d.

[0098] Such a design can effectively make up for the space compressed due to the increase in the number of folding times, making it easier for the electrode assembly 20 to be folded; at the same time, it can also facilitate the stress release of the electrode assembly 20 during the folding process, thereby improving the quality of the laminated battery.

[0099] According to some embodiments of the present application, referring to FIG. 10 , the ratio of the preset displacement 1d to the thickness of the pole piece group 20 in the lamination area 21 is denoted as α, where 1≤α≤5.

[0100] α can be a value between 1 and 5, for example, α can be, but is not limited to, 1, 1.2, 1.5, 2.0, 2.5, 3, 4, 5, etc. When α is 1, the conveying component 11 or the stacking platform 12 moves in a direction away from each other by the thickness of one electrode group 20; when α is 5, the conveying component 11 or the stacking platform 12 moves in a direction away from each other by the thickness of five electrode groups 20.

[0101] The ratio of the preset displacement 1d to the thickness of the electrode group 20 in the stacking area 21 is controlled within a range of 1 to 5, so that the conveying component 11 or the stacking platform 12 can be appropriately displaced backward after folding, leaving a reasonable space for the electrode group 20 between the conveying component 11 and the stacking platform 12, thereby achieving a stable and effective folding process.

[0102] According to some embodiments of the present application, α further satisfies the condition: 2≤α≤3.

[0103] α can take a value between 2 and 3, for example, the value of α can be, but is not limited to, 2, 2.2, 2.4, 2.6, 2.8, 3, etc.

[0104] The value of α is further controlled between 2 and 3, so that after each folding, the space between the conveying component 11 and the stacking platform 12 is more reasonably controlled, thereby making the folding process of the electrode group 20 on the stacking platform 12 more stable.

[0105] According to some embodiments of the present application, please refer to Figure 6. When at least one of the conveying component 11 and the stacking platform 12 moves a first displacement 1a in a direction away from each other, the conveying end 113 of the conveying component 11 is controlled to convey the pole piece group 20 in a direction toward the side of the stacking platform 12 to a third displacement 1c, wherein the third displacement 1c is greater than the first displacement 1a.

[0106] It is easy to understand that since the conveying member 11 is always in operation during the folding process, when the conveying member 11 or the stacking platform 12 moves away from each other, the conveying end 113 of the conveying member 11 also drives the electrode assembly 20 toward the side of the stacking platform 12. At this time, when the conveying member 11 or the stacking platform 12 moves the first displacement 1a in the direction away from each other, the conveying amount of the electrode assembly 20 corresponds to the third displacement 1c.

[0107] Since the third displacement 1c is greater than the first displacement 1a, the amount of the backward movement of the conveying member 11 or the stacking platform 12 will not completely offset the amount of the electrode group 20 conveyed toward the stacking platform 12. In this way, the excess conveying amount will drive the laminated area 21 to continue to fold on the stacking platform 12. Of course, to achieve the above effect, the conveying speed of the conveying member 11, such as the linear speed of the roller, can be controlled to be greater than the moving speed of the conveying member 11 or the stacking platform 12 in the direction away from each other.

[0108] In addition, in some embodiments, when the conveying component 11 or the stacking platform 12 begins to execute the first stage of the movement strategy, that is, when the conveying component 11 or the stacking platform 12 begins to move in a direction away from each other, one of the stacking areas 21 on the stacking platform 12 can be controlled to just begin to fold or fold shortly.

[0109] The third displacement 1c is controlled to be greater than the first displacement 1a, so that the excess conveying amount can drive the lamination area 21 to continue to fold on the stacking platform 12, thereby increasing the space between the conveying component 11 and the stacking platform 12 to release stress while allowing the pole piece group 20 to continue to fold stably.

[0110] According to some embodiments of the present application, the ratio of the third displacement 1 c to the length of the lamination area 21 is denoted as η, where 0.3≤η≤0.7.

[0111] A reasonable value of the third displacement 1c ensures that while the conveying member 11 or the stacking platform 12 is moving away from each other, the corresponding laminated area 21 on the stacking platform 12 is also in the folding process. This allows the folding process of the laminated area 21 to effectively utilize the movement of the conveying member 11 or the stacking platform 12 away from each other, releasing stress and reducing bending and warping of the electrode assembly 20 at the folding area 25.

[0112] η can take a value between 0.3 and 0.7, for example: η can be but not limited to 0.3, 0.4, 0.5, 0.6, 0.7, etc. When η is 0.5, it means that the conveying component 11 has conveyed half of the lamination area 21 of the electrode group 20. If the execution of a movement strategy corresponds to the conveying component 11 conveying a lamination area 21 as an example, in the process of executing the movement strategy, when the first stage of the movement strategy is completed, the conveying component 11 corresponds to conveying half of the lamination area 21; and when the second stage of the movement strategy is completed, the conveying component 11 corresponds to conveying the other half of the lamination area 21. Among them, the first stage is to drive the conveying component 11 and / or the stacking platform 12 to move in a direction away from each other, and the second stage is to drive the conveying component 11 and / or the stacking platform 12 to move in a direction close to each other.

[0113] To facilitate understanding of the length of the lamination area 21 , taking FIG. 2 as an example, the length of the lamination area 21 may be the dimension represented by L in FIG. 2 .

[0114] The ratio of the third displacement 1c to the length of the stacking area 21 is controlled within a range of 0.3 to 0.7, so that the electrode group 20 is transported at least 0.3 of the stacking area 21 when the conveying component 11 or the stacking platform 12 completes the first stage of the movement strategy, which is beneficial to reducing the bending and warping of the electrode group 20 at the folding part 25 and improving the quality of the stacked battery.

[0115] According to some embodiments of the present application, η further satisfies the condition: 0.45≤η≤0.55.

[0116] η can be between 0.45 and 0.55, for example: η can be but not limited to 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, etc.

[0117] Further controlling the ratio of the third displacement 1c to the length of the laminated area 21 within a range of 0.45 to 0.55 is beneficial for further effective control of the folding process of the electrode assembly 20, thereby making the quality of the laminated battery more controllable.

[0118] According to some embodiments of the present application, the ratio of the first displacement 1 a to the length of the lamination area 21 is denoted as λ, where 0.1≤λ≤0.6.

[0119] The ratio of the first displacement 1a to the length of the laminated area 21 can be controlled between 0.1 and 0.6. If it is too small, the increased spacing between the conveying component 11 and the stacking platform 12 is insufficient to release the stress on the laminated area 21, resulting in a greater degree of bending at the folding part 25; if it is too large, the spacing between the conveying component 11 and the stacking platform 12 is too large, affecting the folding efficiency of the electrode group 20 on the stacking platform 12.

[0120] Therefore, the ratio of the first displacement 1a to the length of the lamination area 21 can be, but is not limited to, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, etc. Of course, the value of λ should also be smaller than the value of η.

[0121] With such a design, the ratio of the first displacement 1a to the length of the laminated area 21 is controlled within a range of 0.1 to 0.6, which can effectively take into account both stress release during the folding process and folding efficiency.

[0122] According to some embodiments of the present application, λ further satisfies the condition: 0.4≤λ≤0.5.

[0123] The ratio of the first displacement 1a to the length of the lamination area 21 can be controlled to be between 0.4 and 0.5. For example, λ can be, but is not limited to, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, and the like.

[0124] The ratio of the first displacement 1 a to the length of the lamination area 21 is further controlled to be between 0.4 and 0.5, so as to more accurately control the folding process of the pole piece assembly 20 .

[0125] According to some embodiments of the present application, when the conveying component 11 and / or the stacking platform 12 have completed the movement strategy, the conveying displacement of the conveying end 113 of the conveying component 11 to the pole piece group 20 along the direction toward the side of the stacking platform 12 is the length of at least one stacking area 21.

[0126] When the conveying component 11 and / or the stacking platform 12 completes the movement strategy, the conveying component 11 may output one stacking area 21 or more stacking areas 21. Specifically, in some embodiments, when the conveying component 11 and / or the stacking platform 12 completes the movement strategy, the conveying end 113 of the conveying component 11 conveys the electrode assembly 20 in the direction toward the stacking platform 12 by a length of one stacking area 21.

[0127] In this way, the cycle of the movement strategy is associated with the conveying cycle of the conveying component 11, so that the folding quality of the electrode group 20 is more controllable and the consistency of the product is better.

[0128] According to some embodiments of the present application, referring to FIG. 11 , before step S200 , the step of controlling the movement of the conveying component 11 and / or the stacking platform 12 , the following steps may be further included:

[0129] The minimum distance between the conveying end 113 of the conveying component 11 and the working surface 121 of the stacking platform 12 is controlled to be the initial distance 1e, wherein the ratio of the initial distance 1e to the length of the stacking area 21 is denoted as γ, 1.2≤γ≤2.

[0130] The minimum distance between the conveying end 113 and the working surface 121 refers to the length of the perpendicular line segment obtained by drawing a perpendicular line from the conveying end 113 to the working surface 121, which is the initial distance 1e. For details, please refer to the distance represented by 1e in Figure 11.

[0131] The size of the initial spacing 1e will affect the folding effect of the electrode group 20 on the stacking platform 12. For example, if the initial spacing 1e is less than the length of a laminated area 21, part of the laminated area 21 will still be on the conveying component 11, while the other part has already been folded on the stacking platform 12. This will make it more difficult to release the stress on the laminated area 21 and prevent normal Z-shaped reciprocating folding. If the initial spacing 1e is too large, it will cause more than two laminated areas 21 to be suspended between the conveying component 11 and the stacking platform 12. This will easily cause the folding direction to become disordered during reciprocating folding; at the same time, it will also reduce folding efficiency.

[0132] To this end, the ratio of the initial spacing 1e to the length of the lamination area 21 is controlled between 1.2 and 2. For example, γ can be but is not limited to 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc.

[0133] With this design, the ratio of the initial spacing 1e to the length of the lamination area 21 is controlled between 1.2 and 2, so that there is a suspended lamination area 21 between the conveying component 11 and the lamination platform 12, so that the folding process can be carried out stably; it is also beneficial to improve the folding efficiency.

[0134] According to some embodiments of the present application, γ further satisfies the condition: 1.3≤γ≤1.6.

[0135] The ratio of the initial spacing 1e to the length of the lamination area 21 is controlled between 1.3 and 1.6. For example, γ can be, but is not limited to, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, etc.

[0136] In this way, the ratio of the initial spacing 1e to the length of the lamination area 21 is further controlled between 1.3 and 1.6, which facilitates more precise control of the folding of the electrode assembly 20 and further improves the stability and folding efficiency of the folding process.

[0137] According to some embodiments of the present application, in response to the step of folding the laminated area 21 on the stacking platform 12, it includes: controlling the conveying end 113 of the conveying component 11 to convey the pole piece group 20 in the direction toward one side of the stacking platform 12 to be a fourth displacement, wherein the ratio of the fourth displacement to the length of the laminated area 21 is recorded as ε, 2≤ε≤10.

[0138] The conveying displacement of the electrode group 20 by the conveying end 113 of the conveying component 11 in the direction toward the stacking platform 12 can also be understood as the displacement of the electrode group 20 toward the stacking platform 12 under the action of the conveying component 11. Under the premise that the initial spacing 1e is controlled between 1.2 and 2, the ratio of the conveying displacement of the electrode group 20 by the conveying end 113 of the conveying component 11 to the length of the stacking area 21 is controlled between 2 and 10, so that at least one stacking area 21 has been or begins to be folded on the stacking platform 12. For example, ε can be but is not limited to 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0139] With such a design, the ratio of the conveying displacement of the electrode group 20 by the conveying end 113 of the conveying component 11 to the length of the stacking area 21 is controlled between 2 and 10, so that at least one stacking area 21 has been folded on the stacking platform 12, which facilitates the stress release of the stacking area 21 in the folding process, reduces the bending and warping of the folding part 25, and improves the quality of the laminated battery.

[0140] According to some embodiments of the present application, ε further satisfies the condition: 2.1≤ε≤2.9.

[0141] On the premise that the initial spacing 1e is controlled between 1.2 and 2, the ratio of the conveying displacement of the conveying end 113 of the conveying component 11 to the electrode group 20 and the length of the stacking area 21 is controlled between 2.1 and 2.9. This can reduce the number of folds of the stacking area 21 on the stacking platform 12 before the movement strategy is executed.

[0142] The ratio ε of the conveying displacement of the electrode group 20 by the conveying end 113 of the conveying component 11 to the length of the lamination area 21 can be controlled between 2.1 and 2.9. For example, ε can be but is not limited to 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, etc.

[0143] The ratio of the conveying displacement of the electrode group 20 by the conveying end 113 of the conveying component 11 to the length of the stacking area 21 is further controlled between 2.1 and 2.9, thereby reducing the number of folds of the stacking area 21 on the stacking platform 12 before the movement strategy is executed, so that most of the folding processes on the electrode group 20 can be improved by the movement strategy, thereby further improving the quality of the stacked battery.

[0144] According to some embodiments of the present application, referring to FIG. 12 , the present application provides a pole piece folding control device that utilizes any of the pole piece folding control methods described above. The pole piece folding control device includes a response module 200 and an execution module 300 . The response module 200 is used to determine whether the lamination area 21 is folded on the stacking platform 12 . The execution module 300 is used to control the operation of the conveying component 11 and can control the movement of the conveying component 11 and / or the stacking platform 12 based on the signal fed back by the response module 200 .

[0145] The response module 200 refers to a device that can obtain the execution timing of the movement of the conveying component 11 or the stacking platform 12. For example, the response module 200 can be selected as a displacement sensing module to obtain the conveying displacement of the conveying component 11 to the pole piece group 20. For example, if the obtained conveying displacement is 2.1~2.9, a signal is fed back to the execution module 300; or, the response module 200 can be a visual module, such as a CCD, etc., which feeds back a signal to the execution module 300 when information about the folding action on the stacking platform 12 is obtained.

[0146] The execution module 300 refers to a device that can control the operation of the conveying component 11 and the movement of the conveying component 11 or the stacking platform 12, for example, it can be a single chip microcomputer, an electronic control unit, etc.

[0147] The aforementioned electrode folding control device employs the aforementioned electrode folding control method, utilizing the response module 200 to provide a judgment opportunity for the execution module 300 to control the movement of the conveying component 11 or the stacking platform 12. This provides space for the folding of the stacking area 21, facilitating stress release during folding, reducing the pulling force exerted by the folding stacking area 21 on the unfolded stacking area 21, and reducing the degree of bending and warping of the stacking area 21 at the folding point 25. This reduces the probability of an abnormal gap 1f forming at the folding point 25 of the stacked structure, thereby effectively reducing the probability of lithium deposition at the folding point 25 of the electrode, thereby improving the quality of the stacked battery.

[0148] According to some embodiments of the present application, please refer to Figure 11. The present application provides a pole piece folding device 100 that adopts any of the above pole piece folding control methods. The pole piece folding device 100 includes: a pole piece folding mechanism 10 and a driving mechanism 30. The pole piece folding mechanism 10 includes a stacking platform 12 and a conveying component 11 for conveying a pole piece group 20 and folding the pole piece group 20 back and forth on the stacking platform 12. The driving mechanism 30 is used to drive the conveying component 11 and / or the stacking platform 12 to move.

[0149] The electrode folding mechanism 10 is a device that can fold the electrode assembly 20 back and forth in a Z-shape on the stacking platform 12. The electrode assembly 20 is a composite structure formed by the first electrode 22, the separator 24, and the second electrode 23. To ensure that the electrode assembly 20 can be continuously folded back and forth in a Z-shape to form a laminated structure, the electrode assembly 20 has several continuous and foldable laminated sections 21 along its length, with folds between adjacent laminated sections 21. The folds can be provided on one side of the electrode assembly 20 or on two opposite sides of the electrode assembly 20, i.e., double-sided markings.

[0150] The conveying component 11 refers to a device that provides conveying power for the electrode group 20, which can be a roller structure. For example, the conveying component 11 can include a first roller 111 and a second roller 112 that cooperate with each other, and the electrode group 20 is clamped between the first roller 111 and the second roller 112. At this time, the conveying end 113 of the conveying component 11 acting on the electrode group 20 can be understood as the end of the first roller 111 or the second roller 112 that contacts the electrode group 20. Of course, in some embodiments, the conveying end 113 of the conveying component 11 can also be determined by connecting the center of the circle between the first roller 111 and the second roller 112. The intersection of the connecting line and the first roller 111 or the second roller 112 can also be regarded as the conveying end 113 of the conveying component 11. Among them, one of the first roller 111 and the second roller 112 can be an active roller and the other can be a driven roller; of course, both the first roller 111 and the second roller 112 can be active rollers.

[0151] The stacking platform 12 refers to a structure used to support the stacking structure and provide support force for the folding process. For example, during the folding process, the conveying component 11 moves the electrode group 20 toward the stacking platform 12, so that one end of the stacking area 21 contacts the working surface 121 of the stacking platform 12; as the conveying continues, one end of the stacking area 21 gradually bends and fits toward the working surface 121 with the contact point on the working surface 121 as the inflection point.

[0152] The driving mechanism 30 refers to a device that provides power for the movement of the conveying component 11 or the stacking platform 12, for example: it can be but not limited to a cylinder, a hydraulic cylinder, an electric cylinder, etc. Of course, the driving mechanism 30 can also be a combination structure of a motor and a transmission mechanism, such as: a combination of a motor and a screw mechanism, a combination of a motor and a gear rack, etc.

[0153] In addition, it should be noted that the pole piece folding device 100 of the present application can also adopt the pole piece folding control method proposed in any of the above embodiments.

[0154] The above-mentioned electrode folding device 100, during the folding process of the electrode group 20, drives the electrode group 20 toward the stacking platform 12 through the conveying component 11. When the stacking area 21 on the stacking platform 12 begins to be folded or has already been folded, the driving mechanism 30 drives at least one of the conveying component 11 and the stacking platform 12 to move, so that the distance between the conveying end 113 of the conveying component 11 and at least a portion of the working surface 121 of the stacking platform 12 is widened. This can provide space for the folding of the stacking area 21, facilitate its stress release during folding, reduce the pulling force of the stacking area 21 in the folding state on the stacking area 21 that has not yet been folded, and reduce the degree of bending and warping of the stacking area 21 at the folding part 25. At this time, the probability of the stacking structure generating an abnormal gap 1f at the folding part 25 is reduced, thereby effectively reducing the probability of lithium deposition of the electrode at the folding part 25, thereby improving the quality of the laminated battery.

[0155] According to some embodiments of the present application, the conveying component 11 and the stacking platform 12 are spaced apart along a preset direction X. The driving mechanism 30 is used to drive at least one of the conveying component 11 and the stacking platform 12 to reciprocate in the preset direction X.

[0156] The driving mechanism 30 is used to drive at least one of the conveying component 11 and the stacking platform 12 to move back and forth in the preset direction X. It can be understood that the driving mechanism 30 can drive the conveying component 11 and / or the stacking platform 12 to move in the preset direction X in a direction away from or towards each other.

[0157] When the laminated area 21 is folded on the stacking platform 12, the conveying member 11 or the stacking platform 12 is first moved in a predetermined direction X, increasing the distance between the conveying member 11 and the stacking platform 12. This provides space for the laminated area 21 to fold, facilitates the release of the pulling force on the laminated area 21, and reduces the degree of bending and warping at one end of the laminated area 21. Next, the conveying member 11 or the stacking platform 12 is driven to move in the opposite direction, i.e., toward each other, so that the laminated area 21 is completely folded on the stacking platform 12.

[0158] In this way, the driving mechanism 30 is used to drive the conveying component 11 and / or the stacking platform 12 to reciprocate in the preset direction X, so that during the folding process, the distance between the conveying component 11 and the stacking platform 12 is widened, providing effective clearance space for the folding process of the stacking area 21, facilitating the release of the force on the stacking area 21, reducing the degree of bending and warping on the stacking area 21, and improving the quality of the stacked battery.

[0159] According to some embodiments of the present application, the present application provides a battery production system, which includes the above-mentioned pole piece folding device 100.

[0160] According to some embodiments of the present application, please refer to Figures 1 to 12. The present application provides a method for controlling the folding of the electrode. During the folding process, the electrode group 20 starts to be fed and fed into the double rollers. At this time, the stacking platform 12 does not move, and the double rollers continuously rotate relative to each other to transport the electrode group 20 downward. The initial spacing 1e between the double rollers and the stacking platform 12 is about 1.2 to 2 lengths of the laminated area 21. After the double rollers transport 2.1 to 2.9 lengths of the laminated area 21 downward, the stacking platform 12 starts to move downward at the same time, increasing the spacing between the double rollers and the stacking platform 12, resulting in a gap, reducing the bending of the electrode at the exit of the double rollers, and reducing the pulling force at the corners. Subsequently, after the double rollers continue to transport 0.3 to 0.7 lengths of the laminated area 21, the stacking platform 12 moves down to the bottom dead center (the first displacement 1a is 0.1 to 0.6 lengths of the laminated area 21). Next, the stacking platform 12 begins to move upward, returning to its top dead center (one cycle of the stacking platform 12's up and down movement corresponds exactly to the length of one lamination area 21 conveyed by the twin rollers). The stacking platform 12 then begins to move downward, beginning the next cycle of movement until lamination is complete. It should be noted that each time the stacking platform 12 completes a cycle of movement, it simultaneously moves downward by approximately 1 to 5 thicknesses of the electrode stack 20 in the lamination area 21.

[0161] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for controlling the folding of a pole piece, wherein a pole piece folding mechanism (10) comprises a stacking platform (12) and a conveying component (11) for conveying a pole piece group (20), wherein: The pole piece group (20) has a plurality of lamination areas (21) along its length direction; The pole piece folding control method comprises the following steps: Controlling the conveying component (11) to drive the electrode group (20) to be conveyed toward the stacking platform (12); In response to the lamination area (21) being folded on the stacking platform (12), the conveying component (11) and / or the stacking platform (12) are controlled to continuously and periodically execute a movement strategy in a preset direction (X), wherein the movement strategy includes driving at least one of the conveying component (11) and the stacking platform (12) to move in a direction away from each other; driving at least one of the conveying component (11) and the stacking platform (12) to move in a direction approaching each other, wherein the preset direction (X) is the direction of the interval between the conveying component (11) and the stacking platform (12).

2. The pole piece folding control method according to claim 1, wherein: The step of executing the mobile strategy includes: Controlling the movement amount of at least one of the conveying component (11) and the stacking platform (12) in a direction away from each other to be a first displacement (1a); The movement amount of at least one of the conveying component (11) and the stacking platform (12) in the direction of approaching each other is controlled to be a second displacement (1b), wherein the second displacement (1b) is less than or equal to the first displacement (1a).

3. The pole piece folding control method according to claim 2, wherein: The first displacement (1a) is greater than the second displacement (1b), and the difference between the two is recorded as ΔW, and the thickness of the pole piece group (20) in the lamination area (21) is recorded as h, wherein 1≤ΔW / h≤5.

4. The pole piece folding control method according to claim 3, wherein: ΔW / h also satisfies the following condition: 2≤ΔW / h≤3.

5. The pole piece folding control method according to claim 2, wherein: After the step of controlling the movement amount of at least one of the conveying component (11) and the stacking platform (12) in the direction of approaching each other to be a second displacement (1b), the method comprises: If the first displacement (1a) is equal to the second displacement (1b), in response to each execution of the movement strategy at least once, the conveying component (11) and / or the stacking platform (12) are controlled to move in a direction away from each other by a preset displacement amount (1d).

6. The pole piece folding control method according to claim 5, wherein: The ratio of the preset displacement (1d) to the thickness of the pole piece group (20) in the lamination area (21) is denoted as α, wherein 1≤α≤5.

7. The pole piece folding control method according to claim 6, wherein: α also satisfies the condition: 2≤α≤3.

8. The pole piece folding control method according to any one of claims 2 to 7, wherein: When at least one of the conveying component (11) and the stacking platform (12) moves the first displacement (1a) in a direction away from each other, the conveying end (113) of the conveying component (11) is controlled to convey the pole piece group (20) in a direction toward one side of the stacking platform (12) to a third displacement (1c), wherein the third displacement (1c) is greater than the first displacement (1a).

9. The pole piece folding control method according to claim 8, wherein: The ratio of the third displacement (1c) to the length of the lamination area (21) is denoted as η, wherein 0.3≤η≤0.

7.

10. The pole piece folding control method according to claim 9, wherein: η also satisfies the condition: 0.45≤η≤0.

55.

11. The pole piece folding control method according to any one of claims 8 to 10, wherein: The ratio of the first displacement (1a) to the length of the lamination area (21) is denoted as λ, wherein 0.1≤λ≤0.

6.

12. The pole piece folding control method according to claim 11, wherein: λ also satisfies the condition: 0.4≤λ≤0.

5.

13. The pole piece folding control method according to any one of claims 1 to 12, wherein: When the movement strategy is executed, the conveying displacement of the conveying end (113) of the conveying component (11) to the pole piece group (20) in a direction toward one side of the stacking platform (12) is the length of at least one stacking area (21).

14. The pole piece folding control method according to any one of claims 1 to 13, wherein: Before the step of controlling the conveying component (11) and / or the stacking platform (12) to continuously and periodically execute the movement strategy in a preset direction (X), the method further includes: The minimum distance between the conveying end (113) of the conveying component (11) and the working surface (121) of the stacking platform (12) is controlled to be an initial distance (1e), wherein the ratio of the initial distance (1e) to the length of the stacking area (21) is denoted as γ, 1.2≤γ≤2.

15. The pole piece folding control method according to claim 14, wherein: γ also satisfies the condition: 1.3≤γ≤1.

6.

16. The pole piece folding control method according to claim 14 or 15, wherein: In response to the step of folding the laminated area (21) on the stacking platform (12), the step comprises: The conveying end (113) of the conveying component (11) is controlled to convey the pole piece group (20) in a direction toward one side of the stacking platform (12) as a fourth displacement, wherein the ratio of the fourth displacement to the length of the stacking area (21) is denoted as ε, 2≤ε≤10.

17. The pole piece folding control method according to claim 16, wherein: ε also satisfies the condition: 2.1≤ε≤2.

9.

18. A pole piece folding control device, using the pole piece folding control method according to any one of claims 1 to 17, wherein: The pole piece folding control device comprises: A response module (200) is used to determine whether the laminated area (21) is folded on the stacking platform (12); The execution module (300) is used to control the operation of the conveying component (11), and can control the movement of the conveying component (11) and / or the stacking platform (12) according to the signal fed back by the response module (200).

19. A pole piece folding device, using the pole piece folding control method according to any one of claims 1 to 17, the pole piece folding device comprising: A pole piece folding mechanism (10) comprises a stacking platform (12) and a conveying component (11) for conveying a pole piece group (20) and reciprocatingly folding the pole piece group (20) on the stacking platform (12); A driving mechanism (30) is used for driving the conveying component (11) and / or the stacking platform (12) to move.

20. The pole piece folding device according to claim 19, wherein: The conveying component (11) and the stacking platform (12) are spaced apart along a preset direction (X), and the driving mechanism (30) is used to drive at least one of the conveying component (11) and the stacking platform (12) to move back and forth in the preset direction (X).

21. A battery production system, comprising the pole piece folding device according to claim 19 or 20.

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