Unloading Device and Unloading Method for Wound Electrode Assembly

Abstract

This application belongs to the technical field of battery preparation, and provides a blanking device and a blanking method for a wound electrode assembly. The blanking device includes two groups of clamping needle assemblies. Each clamping needle assembly includes a first clamping needle and a second clamping needle. The first clamping needle is used to clamp the outer wall of the electrode assembly, and the second clamping needle is used to clamp the inner wall of the electrode assembly. The first clamping needle and the second clamping needle of one group of clamping needle assemblies clamp one side of the electrode assembly, and the first clamping needle and the second clamping needle of the other group clamp the other side of the electrode assembly; the two clamping needle assemblies are used to stretch the electrode assembly; the first clamping needle has a first shaping surface, and the shape of the first shaping surface is adapted to the shape of the outer wall surface of the electrode assembly. The first shaping surface is used to fit the outer wall of the electrode assembly. The first clamping needle is provided with a flexible clamping portion, the first shaping surface is a flexible surface provided on the clamping portion, the first shaping surface has a telescopic opening, and the clamping portion is provided with a telescopic slit corresponding to the telescopic opening, and the telescopic slit penetrates the telescopic opening. The aim is to improve the forming quality of the electrode assembly during the pre-stretching process.

Description

Technical Field

[0001] This application belongs to the technical field of battery preparation, and particularly relates to a blanking device and a blanking method for a wound electrode assembly. Background Art

[0002] With the rise of new energy devices represented by new energy vehicles, the battery device has become a key power source. The battery device includes battery cells, and the battery cell is the main component for charging and discharging. The battery cell has an electrode assembly inside, and the electrode assembly includes positive and negative electrode plates and a separator. The positive and negative electrode plates and the separator can be placed in the form of stacking or winding. When in the winding form, the electrode assembly is flat.

[0003] In the preparation process of the wound electrode assembly, first, the positive and negative electrode plates and the separator are wound on a winding needle. At this time, the wound electrode assembly is similar to the outer contour of the winding needle and is approximately circular. After winding, the electrode assembly needs to be removed and then pressed to be flat in the extrusion process. Before extrusion, the electrode assembly needs to be removed by a clamping needle, and the electrode assembly is pre-stretched by the clamping needle, that is, the electrode assembly is stretched from a circular shape to a flat state to facilitate the subsequent extrusion process.

[0004] The clamping needle in the related technology has a poor control effect on the shape and crease of the bent part formed at the stretching position during the pre-stretching of the electrode assembly, resulting in uneven lengths, asymmetrical shapes, and easy wrinkling on both sides of the crease of the electrode assembly, which directly affects the forming quality of the electrode assembly during the subsequent extrusion process. Summary of the Invention

[0005] In view of the above problems, this application provides a blanking device and a blanking method for a wound electrode assembly, aiming to improve the forming quality of the electrode assembly during the pre-stretching process.

[0006] To solve the above problems, in a first aspect, an embodiment of this application provides a blanking device for a wound electrode assembly, including two sets of clamping needle assemblies. Among them, the clamping needle assembly includes:

[0007] A first clamping needle and a second clamping needle arranged at intervals. The first clamping needle is used to be placed outside the wound electrode assembly and clamp the outer wall of the wound electrode assembly, and the second clamping needle is used to be placed inside the electrode assembly and clamp the inner wall of the electrode assembly. The first clamping needle and the second clamping needle of one set of the clamping needle assemblies cooperate with each other to clamp one side of the electrode assembly in the radial direction, and the first clamping needle and the second clamping needle of the other set of the clamping needle assemblies cooperate with each other to clamp the other side of the electrode assembly in the radial direction that is oppositely arranged; the two clamping needle assemblies are also used to stretch the electrode assembly;

[0008] Among them, in the same group of the clamping needle assemblies, the first clamping needle has a first molding surface that is recessed toward one side of the first clamping needle itself, and the shape of the first molding surface is adapted to the shape of the outer wall surface of the electrode assembly. The first molding surface is used to fit the outer wall of the electrode assembly to shape the bent portion formed by stretching the electrode assembly. The first clamping needle is provided with a flexible clamping portion at one end facing the second clamping needle. The first molding surface is a flexible surface provided on the clamping portion, and the flexible surface is used to fit with the outer wall of the electrode assembly during the stretching process of the electrode assembly. The first molding surface has a telescopic opening extending along its length direction, and the clamping portion is provided with an expansion joint at a position corresponding to the telescopic opening, and the expansion joint passes through the telescopic opening.

[0009] This embodiment provides that the contact surface between the first clamping needle and the outer wall of the electrode assembly is a first molding surface. The first molding surface is adapted to the outer wall of the electrode assembly and can be a straight cylindrical surface that is recessed toward the side away from the electrode assembly. This makes the first molding surface similar to the shape of the bent portion of the electrode assembly after being stretched. When the first molding surface contacts the outer wall of the electrode assembly, a pre-added guide surface can be generated on the outer wall, so that it can rely on the first molding surface to form an approximately symmetrical bend during stretching and bending, so that the two corners on the same side of the stretched position of the electrode assembly are subjected to the same force and deformed in the same way, so that the fold is centered, and the electrode assemblies on both sides of the fold are kept as long as possible without wrinkles, thereby improving the quality of pre-stretching. The clamping portion of the first molding surface is set to a flexible material, which can adapt to the shape change of the outer wall when clamping the outer wall of the electrode assembly, and continuously maintain a certain adhesion force on the outer wall, which is conducive to shaping the shape of the outer wall after bending. Since the first plastic surface will undergo a certain degree of plastic deformation, an expansion opening is set on the first plastic surface and connected to the expansion joint. This is conducive to the generation of deformation without generating excessive tension after deformation, thereby reducing the triggering force for deformation of the first plastic surface and allowing it to change in accordance with the shape of the outer wall of the electrode assembly.

[0010] In an embodiment of the first aspect, in the same group of the clamping needle assembly, the second clamping needle has a second molding surface protruding toward one side of the first clamping needle, and the second molding surface is adapted to the shape of the inner wall surface of the electrode assembly, and the second molding surface is used to fit the inner wall of the electrode assembly to shape the bent portion formed by stretching the electrode assembly.

[0011] The effect of this embodiment is that the second molding surface where the second clamping needle contacts the inner wall of the electrode assembly is also designed to be compatible with the inner wall of the electrode assembly, which can be a right cylindrical surface. In this way, when the electrode assembly is stretched, both the inner and outer walls have molding surface support, which can further ensure the molding shape of the bending part of the electrode assembly, achieve the effect of approximately symmetrical bending, and avoid irregular collapse and other deformations at the bending part as much as possible, effectively ensuring the quality of pre-stretching.

[0012] In an embodiment of the first aspect, the second needle holder further has an avoidance surface connected to the second shaping surface. The avoidance surface is located on a side of the second shaping surface away from the first needle holder that is cooperatively clamped, and is used to avoid the inner wall surface of the electrode assembly.

[0013] The effect of this embodiment is that by providing the avoidance surface, the distance between the surface of the second needle holder and the inner wall of the electrode assembly is increased, so that when the second needle holder exits the inner ring, the possibility of contacting the inner wall of the electrode assembly can be reduced, and the preformed shape of the electrode assembly is not damaged.

[0014] In an embodiment of the first aspect, in the same set of needle holder assemblies, in the direction of the first needle holder pointing to the second needle holder, the second shaping surface forms a projection area, and the avoidance surface is within the projection area.

[0015] The effect of this embodiment is that it is equivalent to that the avoidance surface will not exceed the range of the projection area in the direction perpendicular to the direction of the first needle holder pointing to the second needle holder. In this way, with the support of the second shaping surface, the avoidance surface will not contact the inner wall of the electrode assembly.

[0016] In an embodiment of the first aspect, the cross-section of the second needle holder perpendicular to its length direction is in a water droplet shape. The water droplet shape has the avoidance surface, which can prevent other surfaces of the second needle holder from contacting the inner wall of the electrode assembly.

[0017] In an embodiment of the first aspect, the telescopic opening is located in the middle of the first shaping surface in the width direction. This keeps the first shaping surface in a good symmetrical shape, which is beneficial for shaping the outer wall of the electrode assembly.

[0018] In an embodiment of the first aspect, an avoidance groove is provided at one end of the first needle holder for setting the clamping portion, and the end of the clamping portion facing away from the second needle holder is disposed opposite to the notch of the avoidance groove.

[0019] The effect of this embodiment is that the provision of the avoidance groove removes the obstacle to the deformation of the clamping portion, enabling it to deform smoothly.

[0020] In an embodiment of the first aspect, the blanking device further includes a first driving mechanism. The first driving mechanism is drivingly connected to at least one of the first needle holder and the second needle holder of the same set of needle holder assemblies. The first driving mechanism is used to drive the corresponding first needle holder and / or the second needle holder to approach or move away from the electrode assembly to clamp or release the electrode assembly.

[0021] The effect of this embodiment is that the first driving mechanism is provided, which operates stably and can realize the relative movement of the first needle holder and the second needle holder.

[0022] In an embodiment of the first aspect, the blanking device further includes two second driving mechanisms, and the two second driving mechanisms are respectively drivingly connected to one of the groups of the needle clamping assemblies. The second driving mechanism is configured to drive the needle clamping assemblies to approach or move away from each other so as to stretch the electrode assembly, and the second driving mechanism is further configured to drive the needle clamping assemblies so that the second needles enter or exit the inner side of the electrode assembly.

[0023] The effect of this embodiment is that the two needle clamping assemblies can move independently of each other, approach or move away from each other, so as to stretch the electrode assembly, and the second needles of the respective needle clamping assemblies can penetrate into or out of the inner side of the electrode assembly.

[0024] In an embodiment of the first aspect, the first driving mechanism includes:

[0025] A second moving seat, on which the first needle is provided; and

[0026] A second lead screw mechanism, which drives the second moving seat to move so that the first needle approaches or moves away from the second needle.

[0027] In an embodiment of the first aspect, the second driving mechanism includes:

[0028] A first moving seat, on which the second lead screw mechanism, the second moving seat and the second needle are provided; and

[0029] A first lead screw mechanism, which is configured to drive the first moving seat so that the two needle clamping assemblies approach or move away from each other and the second needle enters or exits the inner side of the electrode assembly.

[0030] The effect of this embodiment is that the structural form of the driving mechanism can respectively drive the first needle and the second needle to act adaptively, so as to complete the material taking and the stretching action of the electrode assembly, with stable structure and convenient operation.

[0031] In an embodiment of the first aspect, one end of the first needle is connected to the second moving seat, one end of the second needle is connected to the first moving seat, and both the first needle and the second needle are arranged in the form of cantilevers and are in the same plane.

[0032] The effect of this embodiment is that the first needle and the second needle arranged in the form of cantilevers can conveniently contact the electrode assembly and prevent the structure connecting the first needle and the second needle from touching the electrode assembly.

[0033] In a second aspect, the present application provides a blanking method for a wound electrode assembly, including:

[0034] Using the blanking device of the winding type electrode assembly provided in any one of the embodiments, make the two second clamping needles of the two clamping needle assemblies respectively abut against the inner walls of the opposite two side portions of the electrode assembly in the radial direction along a first direction, and make the two first clamping needles of the two clamping needle assemblies respectively abut against the outer walls of the opposite two side portions of the electrode assembly in the radial direction along the first direction, so as to clamp the opposite two side portions of the electrode assembly by the two groups of clamping needle assemblies along the first direction;

[0035] Withdraw the winding needle that winds the electrode assembly from the electrode assembly;

[0036] Drive the two groups of clamping needle assemblies to move away from each other along the first direction to stretch the electrode assembly;

[0037] Separate the first clamping needle and the second clamping needle from the electrode assembly respectively. This operation method realizes the material taking and stretching of the electrode assembly, and is simple and convenient to operate with high efficiency.

[0038] In an embodiment of the second aspect, before making the two second clamping needles of the two clamping needle assemblies respectively abut against the inner walls of the opposite two side portions of the electrode assembly in the radial direction along a first direction, it further includes: moving the two second clamping needles one by one to insert into the notches of the two winding needles.

[0039] The effect of this embodiment is that taking the length orientation of the notch as the insertion direction of the second clamping needle is equivalent to the notch guiding the second clamping needle, ensuring that the second clamping needle can reach the specified position so that the second clamping needle can accurately clamp the inner wall of the electrode assembly. At the same time, the winding needle includes two notches, and the two notches are symmetrical on the winding needle. In this way, when the two second clamping needles are respectively inserted into the notches, the two second clamping needles are symmetrical, and the clamped positions are also symmetrical. During the next process of stretching the electrode assembly, the electrode assembly can also be stretched symmetrically, which is also beneficial to the withdrawal of the winding needle.

[0040] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically given below. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0042] Figure 1 Schematic structural diagram of a vehicle according to some embodiments of the present application;

[0043] Figure 2 Schematic structural diagram of a battery device provided by some embodiments of the present application;

[0044] Figure 3 Schematic structural diagram of a needle clamping assembly provided by some embodiments of the present application;

[0045] Figure 4 is Figure 3 Schematic structural diagram when the needle clamping assembly clamps and stretches the electrode assembly in

[0046] Figure 5 Schematic structural diagram of the needle clamping assembly clamping the electrode assembly wound on the winding needle provided by some embodiments of the present application;

[0047] Figure 6 is Figure 5 Schematic structural diagram of the needle clamping assembly stretching the electrode assembly in

[0048] Figure 7 is Figure 5 Schematic structural diagram of the first needle in

[0049] Figure 8 Schematic structural diagram of a blanking device for a wound electrode assembly provided by some embodiments of the present application;

[0050] Figure 9 is Figure 8 Top view structural diagram of

[0051] Figure 10 is Figure 8 Schematic structural diagram of the first needle in

[0052] Figure 11 is Figure 8 Schematic structural diagram of the second needle in

[0053] The reference numerals in the specific embodiments are as follows:

[0054] 1000, vehicle;

[0055] 100, battery device; 200, controller; 300, motor;

[0056] 1, needle clamping assembly; 11, first needle; 111, first shaping surface; 112, clamping portion; 113, expansion joint; 114, avoidance groove; 115, expansion port; 12, second needle; 121, second shaping surface; 122, avoidance surface;

[0057] 2, electrode assembly;

[0058] 3. First driving mechanism; 31. First moving seat; 32. Second moving seat; 33. Second lead screw mechanism;

[0059] 4. Winding needle; 41. Notch. Specific embodiments

[0060] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0062] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality of" means more than two, unless otherwise specifically defined.

[0063] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0064] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0065] In the description of the embodiments of the present application, the term "a plurality of" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of sheets" refers to more than two sheets (including two sheets).

[0066] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present application.

[0067] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0068] Currently, from the perspective of the development of the market situation, the application of battery devices is becoming more and more widespread. Battery devices are not only applied to energy storage power systems such as hydraulic, thermal, wind, and solar power stations, but also widely applied to electric transportation tools such as electric bicycles, electric motorcycles, and electric vehicles, as well as multiple fields such as military equipment and aerospace. With the continuous expansion of the battery application field, the market demand is also continuously increasing.

[0069] The battery device is a complete structural entity, including a box body. A plurality of battery cells are arranged inside the box body. In some special scenarios, a single battery cell can also be arranged inside the box body. When there are multiple battery cells, the battery cells in the same row can form a battery cell assembly.

[0070] Such as Figure 2 , an embodiment of the present application provides a battery device 100 (Battery Apparatus), which may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel, or in a mixed connection through a busbar component. The mixed connection refers to the combination of series and parallel connections.

[0071] In some embodiments, the battery cell assembly (Battery Cell Assembly) is usually formed by arranging a plurality of battery cells.

[0072] As an example, the battery cell assembly can be a battery module. The battery module is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells with cable ties.

[0073] In some embodiments, the battery device 100 can be a battery pack. The battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0074] As an example, the battery cell assembly can be a battery module. The battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0075] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing multiple battery cells to the box body.

[0076] As an example, the box body can include a first box body and a second box body. The first box body and the second box body are snapped together so that a closed space is formed inside the box body to accommodate the battery cell assembly. Here, "closed" means covered or closed, which can be sealed or non-sealed. The first box body can be a top cover or a bottom plate.

[0077] As an example, the box body can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0078] In some embodiments, the box body can be a part of the chassis structure of a vehicle. For example, a part of the box body can become at least a part of the floor of the vehicle, or a part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0079] The embodiments of the present application further provide an electrical device having the battery device 100, that is, an electrical device using the battery device 100 as a power source.

[0080] The technical solutions described in the embodiments of the present application are applicable to various power-consuming devices using the battery device 100. Among them, the power-consuming device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range electric vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact drill, a concrete vibrator, and a planer, etc. The embodiments of the present application do not impose special restrictions on the above power-consuming devices.

[0081] The battery device 100 disclosed in the embodiments of the present application can be but is not limited to being used in power-consuming devices such as vehicles, ships, or aircraft. The power-consuming device can use the power supply system equipped with the battery device 100 disclosed in the present application, which is beneficial to improving the use reliability of the power-consuming device.

[0082] For the convenience of description, the following embodiments take the power-consuming device provided in the embodiments of the present application as a vehicle as an example for description.

[0083] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range electric vehicle, etc. The battery device 100 is arranged inside the vehicle 1000, and the battery device 100 can be arranged at the bottom, head, or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000. For example, the battery device 100 can be used as the operating power supply of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0084] In some embodiments of the present application, the battery device 100 can not only be used as the operating power supply of the vehicle 1000, but also be used as the driving power supply of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0085] The battery cells of the battery device 100 are energy storage components capable of charging and discharging reactions. Inside the battery cells is the electrode assembly 2, which includes positive and negative electrode plates and a separator. The positive and negative electrode plates and the separator can be placed in the form of laminations or in a wound form. When arranged in a wound form, the electrode assembly 2 is flat.

[0086] In the preparation process of the wound electrode assembly 2, first, the positive and negative electrode plates and the separator are wound around the winding pin 4. At this time, the wound electrode assembly 2 is similar to the outer contour of the winding pin 4 and is approximately circular. After winding, the electrode assembly 2 needs to be removed and then pressed flat in the extrusion process. Before extrusion, the electrode assembly 2 needs to be removed by the clamping pin, and the electrode assembly 2 is pre-stretched by the clamping pin, that is, the electrode assembly 2 is stretched from a circular shape to a flat state to facilitate the subsequent extrusion process.

[0087] In the related art, the clamping pin has a poor control effect on the shape and crease of the bent part formed at the stretching position during the pre-stretching of the electrode assembly, resulting in inconsistent lengths, asymmetrical shapes, and easy wrinkling on both sides of the crease of the electrode assembly, directly affecting the forming quality of the electrode assembly during the subsequent extrusion process.

[0088] Based on this, please refer to Figures 3 - 11 , this application provides a blanking device for a wound electrode assembly, aiming to improve the forming quality of the electrode assembly 2 during pre-stretching. It includes two sets of clamping pin assemblies 1. Among them, the clamping pin assembly 1 includes:

[0089] The first clamping pin 11 and the second clamping pin 12 are arranged at intervals. The first clamping pin 11 is used to be placed on the outside of the wound electrode assembly 2 and clamp the outer wall of the wound electrode assembly 2, and the second clamping pin 12 is used to be placed inside the electrode assembly 2 and clamp the inner wall of the electrode assembly 2. The first clamping pin 11 and the second clamping pin 12 of a set of clamping pin assemblies 1 cooperate with each other to clamp one side of the electrode assembly 2 in the radial direction, and the first clamping pin 11 and the second clamping pin 12 of the other set of clamping pin assemblies 1 cooperate with each other to clamp the other side of the electrode assembly 2 arranged oppositely in the radial direction; the two clamping pin assemblies 1 are also used to stretch the electrode assembly 2;

[0090] Among them, in the same set of clamping pin assemblies 1, the first clamping pin 11 has a first shaping surface 111 that is concave toward the side of the first clamping pin 11 itself. The shape of the first shaping surface 111 is adapted to the shape of the outer wall surface of the electrode assembly 2, and the first shaping surface 111 is used to fit the outer wall of the electrode assembly 2 to shape the bent part formed by stretching the electrode assembly 2.

[0091] The pin clamping assembly 1 provided in the embodiment of the present application includes a first pin 11 and a second pin 12. The first pin 11 and the second pin 12 cooperate with each other to clamp the electrode assembly 2 arranged in a wound form. The first pin 11 is used to clamp the outer wall of the electrode assembly 2, and the second pin 12 clamps the inner wall of the electrode assembly 2 at a position corresponding to the first pin 11. The first pin 11 and the second pin 12 in the same pin clamping assembly 1 are used for synchronous movement and cooperate with another pin clamping assembly 1 moving in the opposite direction and clamping the electrode assembly 2 at symmetric positions to stretch the electrode assembly 2; the first pin 11 has a concave first shaping surface 111, and the first shaping surface 111 can be a straight cylindrical surface. The first pin 11 clamps the outer wall of the electrode assembly 2 through the first shaping surface 111, and the first shaping surface 111 is used to fit the outer wall of the electrode assembly 2 to shape the bent part formed by stretching the electrode assembly 2.

[0092] Specifically, the first pin 11 and the second pin 12 are in a cooperative relationship, and both jointly clamp the electrode assembly 2. Specifically, the first pin 11 is used to clamp the outer wall of the electrode assembly 2, and the second pin 12 cooperates with the first pin 11 at the corresponding position to clamp the inner wall of the electrode assembly 2, and both jointly clamp the electrode assembly 2.

[0093] The purpose of the first pin 11 and the second pin 12 clamping the electrode assembly 2 is to be able to remove the electrode assembly 2 wound on the winding pin 4, and after removal, the electrode assembly 2 can be stretched, that is, pre-stretched, so that it changes from a circular ring shape to a flat shape initially. The specific implementation form is that during the process of material taking and stretching, two such pin clamping assemblies 1 need to cooperate. That is, the first pin 11 and the second pin 12 of one pin clamping assembly 1 clamp one place of the electrode assembly 2, and the first pin 11 and the second pin 12 of another pin clamping assembly 1 clamp another place of the electrode assembly 2. The two places can be symmetric positions. After clamping, then the winding pin 4 is withdrawn to complete the material taking. After the material taking is completed, the two pin clamping assemblies 1 move away from each other, thereby pre-stretching the electrode assembly 2. Among them, the second pin 12 is located at the inner wall of the electrode assembly 2 and can contact the electrode assembly 2 from the inner wall by penetrating into the notch 41 of the winding pin 4.

[0094] In the related art, the surface of the pin contacting the electrode assembly cannot apply a bending elastic deformation force to the positive and negative electrode materials at the corners where the electrode assembly deforms after stretching during the stretching process, resulting in different forces on the two corners on both sides of the same-side stretching position of the electrode assembly during the stretching process. After plastic deformation, the crease positions are different and cannot overlap, so the inner ring crease position will be lifted, resulting in inconsistent lengths of the two parts on both sides of the crease of the stretched electrode assembly, causing wrinkling or an increase in the distance between layers, and local deformation exceeding the specification, directly affecting the forming quality of the subsequent extrusion process.

[0095] Based on this, this embodiment provides that the contact surface between the first clamping needle 11 and the outer wall of the electrode assembly 2 is a first molding surface 111. The first molding surface 111 is adapted to the outer wall surface of the electrode assembly 2 and can be a straight cylindrical surface that is recessed toward the side away from the electrode assembly 2. In this way, the first molding surface 111 is similar in shape to the bent portion of the electrode assembly 2 after being stretched. When the first molding surface 111 contacts the outer wall of the electrode assembly 2, a pre-added guide surface can be generated for the outer wall, so that it can rely on the first molding surface 111 to form an approximately symmetrical bend during stretching and bending, so that the corners on both sides of the stretching position on the same side of the electrode assembly 2 are subjected to consistent force and deformation, so that the fold is centered, and the electrode assemblies 2 on both sides of the fold are kept as long as possible without generating wrinkles, thereby improving the quality of pre-stretching.

[0096] The right cylindrical surface is a portion of the cylindrical surface. It is a curved and symmetrical surface, and the curvature can be adaptively adjusted according to the size of the electrode assembly 2. The right cylindrical surface is equivalent to a contoured surface, so that when the electrode assembly 2 is stretched, it fits with the outer wall of the electrode assembly 2, thereby shaping the outer wall of the electrode assembly 2 and making the electrode assembly 2 achieve approximately symmetrical bending.

[0097] In some embodiments, see Figure 3 and Figure 4 as well as Figure 11 In the same group of clamping needle assemblies 1, the second clamping needle 12 has a second molding surface 121 protruding toward the side of the first clamping needle 11. The second molding surface 121 is adapted to the shape of the inner wall surface of the electrode assembly 2. The second molding surface 121 is used to fit the inner wall of the electrode assembly 2 to shape the bending portion formed by stretching the electrode assembly 2.

[0098] The second molding surface 121 can also be a right cylindrical surface. The second clamping needle 12 clamps the inner wall of the electrode assembly 2 through the second molding surface 121. The second molding surface 121 is used to fit the inner wall of the electrode assembly 2 to shape the bent portion formed by stretching the electrode assembly 2.

[0099] Specifically, this embodiment provides a second clamping needle 12, and the surface where the second clamping needle 12 contacts the inner wall of the electrode assembly 2 is designed to be a second molding surface 121. Since the second clamping needle 12 is located on the inner side of the electrode assembly 2, the radius corresponding to the right cylindrical surface of the second clamping needle 12 is smaller than the radius of the right cylindrical surface of the first clamping needle 11.

[0100] The second clamping needle 12 contacts the inner wall of the electrode assembly 2 through the second molding surface 121. When the first clamping needle 11 and the second clamping needle 12 move to stretch the electrode assembly 2, the second clamping needle 12 is used to push the inner wall of the electrode assembly 2. During the pushing process, the inner wall of the electrode assembly 2 will adhere to the second molding surface 121 and form a shape similar to the second molding surface 121.

[0101] Therefore, the effect of this embodiment is that the second plastic shaping surface 121 in contact with the inner wall of the electrode assembly 2 of the second pinching needle 12 is also designed to be a surface adapted to the inner wall of the electrode assembly 2, which can be a straight cylindrical surface. In this way, when the electrode assembly 2 is stretched, both the inner and outer walls have the support of the plastic shaping surface, which can further ensure the plastic shaping shape at the bending part of the electrode assembly 2, achieving the effect of approximately symmetric bending, minimizing irregular collapses and other deformations at the bending part, and effectively ensuring the quality of pre-stretching formation.

[0102] In some embodiments, please refer to Figure 3 and Figure 4 as well as Figure 11 , the second pinching needle 12 further has an avoidance surface 122 connected to the second plastic shaping surface 121. The avoidance surface 122 is located on the side of the second plastic shaping surface 121 away from the first pinching needle 11 for mating clamping and is used to avoid the inner wall surface of the electrode assembly 2.

[0103] Other surfaces of the second pinching needle 12 except the second plastic shaping surface 121 include the avoidance surface 122, and the avoidance surface 122 can be a surface inclined towards the side away from the inner wall of the electrode assembly 2.

[0104] Specifically, the second pinching needle 12 is located at the inner wall of the electrode assembly 2, that is, it penetrates into the ring of the electrode assembly 2. When the electrode assembly 2 is stretched to be flat and before the extrusion process, the second pinching needle 12 and the first pinching needle 11 need to be disengaged from the electrode assembly 2, that is, the second pinching needle 12 at the inner ring needs to be withdrawn from the inner ring. During this process, since the electrode assembly 2 is in a pre-flat state, it may come into contact with the inner wall and cause friction when withdrawn, resulting in deformation of the electrode assembly 2. Therefore, this embodiment provides other surfaces including the avoidance surface 122 except the second plastic shaping surface 121.

[0105] The avoidance surface 122 can be an inclined surface, inclined towards the side away from the inner wall of the electrode assembly 2.

[0106] The effect of this embodiment is that the avoidance surface 122 is provided, increasing the distance between the surface of the second pinching needle 12 and the inner wall of the electrode assembly 2, so that the possibility of contact with the inner wall of the electrode assembly 2 can be reduced when the second pinching needle 12 is withdrawn from the inner ring, without damaging the preformed shape of the electrode assembly 2.

[0107] In some embodiments, in the same set of pinching needle assemblies 1, in the direction of the first pinching needle 11 pointing to the second pinching needle 12, the second plastic shaping surface 121 forms a projection area, and the avoidance surface 122 is within the projection area.

[0108] Specifically, the two side surfaces of the electrode assembly 2 that has been stretched into a flat shape are parallel to the direction in which the first clamping needle 11 points to the second clamping needle 12. In this direction, the second molding surface 121 forms a projection area, and the avoidance surface 122 is in the projection area, which is equivalent to the avoidance surface 122 not exceeding the range of the projection area in the direction perpendicular to the direction in which the first clamping needle 11 points to the second clamping needle 12. This is equivalent to having the support of the second molding surface 121, so that the avoidance surface 122 will not contact the inner wall of the electrode assembly 2.

[0109] In some embodiments, the cross-section of the second clamping needle 12 is teardrop-shaped. The teardrop-shaped shape has the avoidance surface 122 , which can prevent other surfaces of the second clamping needle 12 from contacting the inner wall of the electrode assembly 2 .

[0110] In some embodiments, see Figures 5 - 7 as well as Figure 10 A flexible clamping portion 112 is provided at one end of the first clamping needle 11 facing the second clamping needle 12. The first molding surface 111 is a flexible surface provided on the clamping portion 112. The flexible surface is used to fit with the outer wall of the electrode assembly 2 during the stretching process of the electrode assembly 2.

[0111] A clamping portion 112 is provided at one end of the first clamping needle 11 facing the electrode assembly 2, and the first molding surface 111 is formed on the clamping portion 112. The clamping portion 112 is made of flexible material, specifically plastic material, so that the first molding surface 111 remains in contact with the outer wall for molding when squeezing the outer wall of the electrode assembly 2.

[0112] Specifically, during the stretching process of the electrode assembly 2, the second clamping pin 12 serves to push up the inner wall of the electrode assembly 2, so that the inner wall adheres to the second molding surface 121 and can form the shape of the second molding surface 121. However, the first clamping pin 11 does not directly push up during movement, but rather supports the electrode assembly 2. Because during stretching, the first clamping pin 11 is in a retreated state and the second clamping pin 12 is in a pushing state. Therefore, the outer wall of the electrode assembly 2 is not very tightly fitted with the first molding surface 111 of the first clamping pin 11.

[0113] To address this situation, this embodiment provides a clamping portion 112 made of a flexible material. The first plastic surface 111 is a flexible surface formed on the clamping portion 112, which has a certain degree of plastic deformability. Plastic deformation means that it can undergo a certain deformation and can recover to its original shape.

[0114] like Figure 5 and Figure 6, before stretching the counter electrode assembly 2, the outer wall of the counter electrode assembly 2 first adheres to both ends of the first shaping surface 111. Since the arc radius corresponding to the first shaping surface 111 is smaller than the arc radius of the counter electrode assembly 2, it first contacts both ends of the first shaping surface 111 instead of adhering to the central region of the first shaping surface 111. When Figure 5 the coiling needle 4 in Figure 5 is withdrawn and the counter electrode assembly 2 is stretched, at this time, under the action of the extrusion force on both ends, the clamping portion 112 starts to deform. By deforming, the arc of the first shaping surface 111 expands, which is equivalent to increasing the arc radius of the first shaping surface 111, so that it can completely adhere to the outer wall of the counter electrode assembly 2, thereby shaping the outer wall. As the stretching continues, the arc radius of the outer wall of the counter electrode assembly 2 becomes smaller, and the arc radius of the first shaping surface 111 also becomes smaller accordingly, that is, it still maintains a good adhering state to realize the shaping of the outer wall.

[0115] Therefore, the effect of this embodiment is that the clamping portion 112 provided with the first shaping surface 111 is made of a flexible material, which can change correspondingly according to the shape change of the outer wall when clamping the outer wall of the counter electrode assembly 2, and continuously maintains a certain adhesive force to the outer wall, which is beneficial to shaping the shape after the outer wall is bent.

[0116] In some embodiments, please refer to Figure 7 and Figure 10 , the first shaping surface 111 has a telescopic opening 115 extending along its length direction, and the clamping portion 112 is provided with a telescopic slit 113 corresponding to the position of the telescopic opening 115, and the telescopic slit 113 penetrates through the telescopic opening 115.

[0117] Specifically, the telescopic opening 115 is opened on the first shaping surface 111, and the telescopic slit 113 is opened on the clamping portion 112, and the two are communicated.

[0118] Specifically, since the first shaping surface 111 will undergo a certain amount of plastic deformation, a telescopic opening 115 is provided on the first shaping surface 111 and communicated with the telescopic slit 113. This is beneficial to the generation of deformation and will not cause excessive tension after deformation, so that the triggering force for the first shaping surface 111 to deform is reduced, and it can change according to the shape of the outer wall of the counter electrode assembly 2.

[0119] The first shaping surface 111 has a certain length, which is the length direction of the counter electrode assembly 2. The telescopic slit 113 is opened along the length direction, which is beneficial to the overall telescopic deformation.

[0120] In some embodiments, the telescopic opening 115 is located in the middle of the first shaping surface 111 along the width direction.

[0121] The width direction of the first shaping surface 111 is perpendicular to the length direction. When the telescopic opening 115 is located in the middle of the width direction, it can cause the parts on both sides of the telescopic opening 115 to deform symmetrically, enabling the first shaping surface 111 to maintain a good symmetrical shape, which is beneficial for shaping the outer wall of the electrode assembly 2.

[0122] In some embodiments, referring to Figure 7 and Figure 10 , an avoidance groove 114 is provided at one end of the first clamping needle 11 for setting the clamping portion 112, and the end of the clamping portion 112 facing away from the second clamping needle 12 is disposed opposite to the notch 41 of the avoidance groove 114.

[0123] Specifically, the clamping portion 112 will deform. When the arc radius of the first shaping surface 111 becomes larger, the expansion joint 113 will expand, and when it becomes smaller, the expansion joint 113 will contract. When the expansion joint 113 contracts, the side of the clamping portion 112 opposite to the first shaping surface 111 will protrude towards the avoidance groove 114 when the expansion joint 113 contracts, and the function of the avoidance groove 114 is to avoid the protruding part, enabling the deformation to occur smoothly.

[0124] The effect of this embodiment is that the provision of the avoidance groove 114 removes the obstruction to the deformation of the clamping portion 112, enabling the deformation to occur smoothly.

[0125] In some embodiments, referring to Figure 8 and Figure 9 , the blanking device further includes a first driving mechanism 3. The first driving mechanism 3 is drivingly connected to at least one of the first clamping needle 11 and the second clamping needle 12 of the same set of clamping needle assemblies 1. The first driving mechanism 3 is used to drive the corresponding first clamping needle 11 and / or the second clamping needle 12 to approach or move away from the electrode assembly 2 to clamp or release the electrode assembly 2.

[0126] This embodiment provides the first driving mechanism 3. Each set of clamping needle assemblies 1 is correspondingly provided with a first driving mechanism 3. The first driving mechanism 3 can be used to drive the first clamping needle 11 to move, or can be used to drive the second clamping needle 12 to move, or can drive both to move simultaneously. Its purpose is to enable the two to move away from or close to each other, thereby clamping or releasing the electrode assembly 2.

[0127] The effect of this embodiment is that the provision of the first driving mechanism 3 has stable operation and can realize the relative movement of the first clamping needle 11 and the second clamping needle 12.

[0128] In some embodiments, referring to Figure 8 and Figure 9, the blanking device further includes two second driving mechanisms, which are respectively drivingly connected to one set of the needle clamping assemblies 1. The second driving mechanism is used to drive the needle clamping assemblies 1 to approach or move away from each other to stretch the electrode assembly 2, and the second driving mechanism is also used to drive the needle clamping assemblies 1 so that the second needles 12 enter or exit the inner side of the electrode assembly 2.

[0129] Specifically, in this embodiment, there are two second driving mechanisms, which are respectively drivingly connected to one needle clamping assembly 1.

[0130] The effect of this embodiment is that the two needle clamping assemblies 1 can move independently, approach or move away from each other, so as to stretch the electrode assembly 2, and the second needles 12 of the respective needle clamping assemblies 1 can penetrate into or out of the inner side of the electrode assembly 2.

[0131] In some embodiments, please refer to Figure 8 and Figure 9 , the first driving mechanism 3 includes:

[0132] A second moving seat 32, on which a first needle 11 is provided; and

[0133] A second lead screw mechanism 33, which drives the second moving seat 32 to move so that the first needle 11 approaches or moves away from the second needle 12.

[0134] The second driving mechanism includes:

[0135] A first moving seat 31, on which the second lead screw mechanism 33, the second moving seat 32 and the second needle 12 are provided; and

[0136] A first lead screw mechanism, which is used to drive the first moving seat 31 so that the two needle clamping assemblies 1 approach or move away from each other and the second needle 12 enters or exits the inner side of the electrode assembly 2.

[0137] The first moving seat 31 can move along a preset direction, so that the second needle 12 moves in the preset direction, so that the second needle 12 completes the actions of inserting into the notch 41 of the coiling needle 4, contacting the inner wall of the electrode assembly 2, and stretching the electrode assembly 2.

[0138] When the first moving seat 31 moves, the second moving seat 32 moves accordingly. However, the second moving seat 32 can also move relative to the first moving seat 31 independently on the first moving seat 31. This is equivalent to the first clamping pin 11 being able to move relative to the first moving seat 31 in addition to moving with the first moving seat 31. For example, when the second clamping pin 12 needs to be inserted into the notch 41 of the coiling pin 4, the first clamping pin 11 moves away from the second clamping pin 12, that is, away from the electrode assembly 2, by means of the movement of the second moving seat 32 to avoid touching the electrode assembly 2. After the second clamping pin 12 is in place, the first clamping pin 11 can move closer to the second clamping pin 12, that is, closer to the electrode assembly 2, by means of the movement of the second moving seat 32 alone, and contact the outer wall of the electrode assembly 2 to cooperate with the second clamping pin 12 to clamp the electrode assembly 2. When stretching the electrode assembly 2, the first moving seat 31 moves as a whole, driving the first clamping pin 11 and the second clamping pin 12 to move synchronously, so as to stretch the electrode assembly 2.

[0139] The effect of this embodiment is that the structural form of the driving mechanism can adaptively drive the first clamping pin 11 and the second clamping pin 12 to act respectively, so as to complete the material taking and the stretching action of the electrode assembly 2, with stable structure and convenient operation.

[0140] Specifically, the first lead screw mechanism and the second lead screw mechanism 33 are not limited to only one set of lead screw components. For example, the first lead screw mechanism can include two sets of lead screw components, and each set of lead screw components can make the first moving seat 31 move along a specific direction, and the two sets of lead screw components can make it move along two perpendicular directions. And the second lead screw mechanism 33 can have only one set of lead screw components to make the second moving seat 32 move, so as to drive the first clamping pin 11 to approach or move away from the second clamping pin 12.

[0141] When the first lead screw mechanism includes two sets of lead screw components, the nut of the first lead screw component is connected to the second lead screw component to make the second lead screw component move along one direction, and the nut of the second lead screw component is connected to the first moving seat 31 to make the first moving seat 31 move along the second direction. One direction can be the direction in which the first clamping pin 11 approaches and moves away from the second clamping pin 12, that is, the direction of stretching the electrode assembly 2, and the other direction can be the direction of inserting or withdrawing the second clamping pin 12 into or from the inside of the electrode assembly 2.

[0142] Therefore, in this embodiment, the movement of the first clamping pin 11 and the second clamping pin 12 can be realized through the lead screw mechanism, with simple and fast operation and stable operation.

[0143] In some embodiments, please refer to Figures 9 - 11 , one end of the first clamping pin 11 is connected to the second moving seat 32, one end of the second clamping pin 12 is connected to the first moving seat 31, and the first clamping pin 11 and the second clamping pin 12 are both arranged in the form of cantilevers and are in the same plane.

[0144] Specifically, the first needle clamp 11 and the second needle clamp 12 arranged in a cantilever form can facilitate contact with the electrode assembly 2 and prevent the structure connecting the first needle clamp 11 and the second needle clamp 12 from touching the electrode assembly 2. For example, when the second needle clamp 12 is inserted into the notch 41 of the winding needle 4, it can be smoothly inserted to a sufficient depth without being hindered by the structure connecting the second needle clamp 12. At the same time, the first needle clamp 11 and the second needle clamp 12 being in a plane is also beneficial to the stretching of the electrode assembly 2.

[0145] Please refer to Figure 8 and Figure 9 , this application also provides a method for unloading a wound electrode assembly, using the unloading device for a wound electrode assembly provided in any one of the embodiments, specifically:

[0146] Make the two second needle clamps 12 of the two needle clamp assemblies 1 respectively abut against the inner walls of the opposite two side parts of the electrode assembly 2 along the radial direction in the first direction, and make the two first needle clamps 11 of the two needle clamp assemblies 1 respectively abut against the outer walls of the opposite two side parts of the electrode assembly 2 along the radial direction in the first direction, so that the two needle clamp assemblies 1 clamp the opposite two side parts of the electrode assembly 2 along the first direction;

[0147] Withdraw the winding needle 4 that winds the electrode assembly 2 from the electrode assembly 2;

[0148] Drive the two needle clamp assemblies 1 to move away from each other along the first direction to stretch the electrode assembly 2;

[0149] Make the first needle clamp 11 and the second needle clamp 12 respectively disengage from the electrode assembly 2.

[0150] Specifically, this embodiment provides a method for unloading the electrode assembly 2. Specifically, after the winding needle 4 has wound the electrode assembly 2, the electrode assembly 2 is wrapped around the outer surface of the circular winding needle 4 in an annular structure, and the electrode assembly 2 needs to be removed. The winding needle 4 has a notch opened along the length direction of the electrode assembly 2, that is, the notch 41.

[0151] In this embodiment, the first needle clamp 11 and the second needle clamp 12 of the two needle clamp assemblies 1 respectively clamp the symmetric positions of the electrode assembly 2 to fix the electrode assembly 2. After fixing, the winding needle 4 is withdrawn, then the electrode assembly 2 is removed, and then the needle clamps of the two needle clamp assemblies 1 move in the reverse direction to achieve stretching.

[0152] During specific operation, first abut the second needle clamp 12 against the inner wall, then abut the first needle clamp 11 against the outer wall. Then, after the electrode assembly 2 is fixed, the winding needle 4 can be withdrawn. Then, the two needle clamp assemblies 1 move in the reverse direction to move away from each other, so that the electrode assembly 2 can be pre-stretched and formed. At this time, the first needle clamp 11 and the second needle clamp 12 can be withdrawn to enter the extrusion process.

[0153] This operation method realizes the material taking and stretching of the electrode assembly 2, with simple and convenient operation and high efficiency.

[0154] In some embodiments, before the two second clamping needles 12 of the two clamping needle assemblies 1 respectively abut against the inner walls of the opposite side parts of the electrode assembly 2 in the radial direction along the first direction, it further includes: moving the two second clamping needles 12 one by one to be inserted into the notches 41 of the two coiling needles 4.

[0155] Specifically, move the positions of the two second clamping needles 12 to align the two second clamping needles 12 with the two notches 41 of the coiling needle 4 respectively and insert them into the notches 41 by moving, and then move the second clamping needles 12 again to make them abut against the inner wall of the electrode assembly 2.

[0156] The coiling needle 4 includes a notch 41, and the notch 41 is a gap on the coiling needle 4 for the second clamping needle 12 to extend into, so that the second clamping needle 12 can abut against the electrode assembly 2 from the inner wall of the electrode assembly 2, realizing the clamping of the electrode assembly 2.

[0157] The effect of this embodiment is that taking the length orientation of the notch 41 as the insertion direction of the second clamping needle 12 is equivalent to the notch 41 guiding the second clamping needle 12, ensuring that the second clamping needle 12 can reach the specified position so that the second clamping needle 12 can accurately clamp the inner wall of the electrode assembly 2. At the same time, the coiling needle 4 includes two notches 41, and the two notches 41 are symmetrical on the coiling needle 4. In this way, when the two second clamping needles 12 are respectively inserted into the notches 41, the two second clamping needles 12 are symmetrical, and the clamped positions are also symmetrical. During the next process of stretching the electrode assembly 2, the electrode assembly 2 can also be stretched symmetrically, which is also beneficial to the withdrawal of the coiling needle 4.

[0158] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A blanking device for a wound electrode assembly, characterized in that, It includes two sets of needle clamping assemblies. Among them, each needle clamping assembly includes: A first needle and a second needle arranged at intervals. The first needle is used to be placed outside the wound electrode assembly and clamp the outer wall of the wound electrode assembly, and the second needle is used to be placed inside the electrode assembly and clamp the inner wall of the electrode assembly. The first needle and the second needle of one set of the needle clamping assemblies cooperate with each other to clamp one side of the electrode assembly in the radial direction, and the first needle and the second needle of the other set of the needle clamping assemblies cooperate with each other to clamp the other side of the electrode assembly arranged oppositely in the radial direction; the two needle clamping assemblies are also used to stretch the electrode assembly; Among them, in the same set of the needle clamping assemblies, the first needle has a first shaping surface recessed towards the side of the first needle itself. The shape of the first shaping surface is adapted to the shape of the outer wall surface of the electrode assembly. The first shaping surface is used to fit the outer wall of the electrode assembly to shape the bent portion formed by stretching the electrode assembly. One end of the first needle facing the second needle is provided with a flexible clamping portion. The clamping portion is made of a plastic material that can undergo plastic deformation. The plastic deformation is a deformation that can occur and can return to its original shape. The first shaping surface is a flexible surface provided on the clamping portion. The flexible surface is used to fit the outer wall of the electrode assembly during the stretching process of the electrode assembly. The first shaping surface has a telescopic opening extending along its length direction, and the clamping portion is provided with a telescopic slit corresponding to the position of the telescopic opening. The telescopic slit penetrates the telescopic opening.

2. The blanking device for the winding electrode assembly according to claim 1, characterized in that, In the same set of the needle clamping assemblies, the second needle has a second shaping surface protruding towards the first needle. The shape of the second shaping surface is adapted to the shape of the inner wall surface of the electrode assembly. The second shaping surface is used to fit the inner wall of the electrode assembly to shape the bent portion formed by stretching the electrode assembly.

3. The blanking device of the winding electrode assembly according to claim 2, characterized in that The second needle also has an avoidance surface connected to the second shaping surface. The avoidance surface is located on the side of the second shaping surface away from the first needle that cooperates for clamping and is used to avoid the inner wall surface of the electrode assembly.

4. The blanking device for the wound electrode assembly according to claim 3, characterized in that, In the same set of the needle clamping assemblies, in the direction from the first needle pointing to the second needle, the second shaping surface forms a projection area, and the avoidance surface is within the projection area.

5. The blanking device for the wound electrode assembly according to claim 3, characterized in that, The cross-section of the second needle perpendicular to its length direction is in a water droplet shape.

6. The blanking device for the winding type electrode assembly according to claim 1, characterized in that The telescopic opening is located in the middle of the first shaping surface in the width direction.

7. The blanking device for the wound electrode assembly according to claim 1, characterized in that, An avoidance groove is provided at one end of the first needle where the clamping portion is arranged, and the end of the clamping portion facing away from the second needle is arranged opposite to the notch of the avoidance groove.

8. The blanking device for the wound electrode assembly according to any one of claims 1-5, characterized in that, The blanking device also includes a first driving mechanism. The first driving mechanism is drivingly connected to at least one of the first needle and the second needle of the same set of the needle clamping assemblies. The first driving mechanism is used to drive the corresponding first needle and / or the second needle to approach or move away from the electrode assembly to clamp or release the electrode assembly.

9. The blanking device for the wound electrode assembly according to claim 8, wherein, The blanking device further includes two second driving mechanisms, and the two second driving mechanisms are respectively drivingly connected to one of the groups of the needle clamping assemblies. The second driving mechanism is used to drive the needle clamping assemblies to approach or separate from each other so as to stretch the electrode assembly, and the second driving mechanism is further used to drive the needle clamping assemblies so that the second needles enter or exit the inner side of the electrode assembly.

10. The blanking device for a wound electrode assembly according to claim 9, wherein The first driving mechanism includes: A second moving seat, on which the first needle is provided; and A second lead screw mechanism, which drives the second moving seat to move so that the first needle approaches or separates from the second needle.

11. The blanking device for a wound electrode assembly according to claim 10, wherein The second driving mechanism includes: A first moving seat, on which the second lead screw mechanism, the second moving seat and the second needle are arranged; and A first lead screw mechanism, which is used to drive the first moving seat so that the two needle clamping assemblies approach or separate from each other and the second needle enters or exits the inner side of the electrode assembly.

12. The blanking device of the winding electrode assembly according to claim 11, characterized in that, The first needle is connected to the second moving seat at one end, and the second needle is connected to the first moving seat at one end. Both the first needle and the second needle are arranged in a cantilever form and are in the same plane.

13. A blanking method for a wound electrode assembly, characterized in that, Including: Using the blanking device for a wound electrode assembly according to any one of claims 1-12, making the two second needles of the two needle clamping assemblies respectively abut against the inner walls of the opposite two side portions of the electrode assembly in the radial direction along a first direction, and making the two first needles of the two needle clamping assemblies respectively abut against the outer walls of the opposite two side portions of the electrode assembly in the radial direction along the first direction, so that the two groups of needle clamping assemblies clamp the opposite two side portions of the electrode assembly along the first direction; Making the winding needle for winding the electrode assembly withdraw from the electrode assembly; Driving the two groups of needle clamping assemblies to move away from each other along the first direction to stretch the electrode assembly; Making the first needle and the second needle respectively disengage from the electrode assembly.

14. The blanking method of the winding type electrode assembly according to claim 13, characterized in that, Before making the two second needles of the two needle clamping assemblies respectively abut against the inner walls of the opposite two side portions of the electrode assembly in the radial direction along the first direction, it further includes: moving the two second needles to be respectively inserted into the notches of the two winding needles one by one.

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