Discharging device and discharging method for winding type electrode assembly

Abstract

The invention belongs to the technical field of battery preparation, and provides a blanking device and a blanking method of a winding type electrode assembly, the blanking device comprises two groups of clamping needle assemblies, each clamping needle assembly comprises a first clamping needle and a second clamping needle, the first clamping needle is used for clamping the outer wall of the electrode assembly, and the second clamping needle is used for clamping the inner wall of the electrode assembly; one side part of the electrode assembly is clamped by the first clamping needle and the second clamping needle of one group of clamping needle assembly, and the other side part of the electrode assembly is clamped by the first clamping needle and the second clamping needle of the other group of clamping needle assembly; the two needle clamping assemblies are used for stretching the electrode assembly; the first clamping needle is provided with a first molding surface, the shape of the first molding surface is matched with the shape of the outer wall surface of the electrode assembly, the first molding surface is used for being attached to the outer wall of the electrode assembly, the first clamping needle is provided with a flexible clamping part, the first molding surface is a flexible surface arranged on the clamping part, the first molding surface is provided with a telescopic opening, and the clamping part is provided with an expansion joint corresponding to the telescopic opening; the expansion joint penetrates through the expansion opening. The forming quality of the electrode assembly in the pre-stretching process is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of battery preparation, and in particular relates to a feeding device and a feeding method for a wound electrode assembly. Background Art

[0002] With the rise of new energy equipment represented by new energy vehicles, battery devices have become a key source of power. Battery devices include battery cells. Battery cells are the main components for charging and discharging. Battery cells have electrode assemblies inside. The electrode assemblies include positive and negative electrode sheets and separators. The positive and negative electrode sheets and separators can be placed in the form of stacked sheets or in a wound form. When in a wound form, the electrode assembly is flat.

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

[0004] The clamping needle in the related technology has poor control effect on the shape of the bent part and the crease formed at the stretching position when pre-stretching the electrode assembly, resulting in the electrode assembly having different lengths on both sides of the crease, asymmetric shapes, and prone to wrinkling, which directly affects the forming quality of the electrode assembly in the subsequent extrusion process. Summary of the invention

[0005] In view of the above problems, the present application provides a material unloading device and a material unloading 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 the present application provides a feeding device for a wound electrode assembly, comprising two sets of clamping needle assemblies, wherein the clamping needle assemblies include: A first clamping needle and a second clamping needle are arranged at intervals, the first clamping needle is used to be placed on the outside of the wound electrode assembly and clamp the outer wall of the wound electrode assembly, the second clamping needle is used to be placed on the inside of the electrode assembly and clamp the inner wall of the electrode assembly, the first clamping needle and the second clamping needle of one group 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 another group of the clamping needle assemblies cooperate with each other to clamp another side of the electrode assembly arranged oppositely in the radial direction; the two clamping needle assemblies are also used to stretch the electrode assembly; 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, 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 bending portion formed by stretching the electrode assembly, the first clamping needle faces one end of the second clamping needle and is provided with a flexible clamping portion, the first molding surface is a flexible surface provided on the clamping portion, 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, 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.

[0007] 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, and the first molding surface is adapted to the outer wall surface of the electrode assembly, and can be a straight cylindrical surface that is recessed toward the side away from the electrode assembly, so that the first molding surface is similar to the shape of the bent portion of the electrode assembly after being stretched, and when the first molding surface contacts the outer wall of the electrode assembly, a pre-added guide surface can be generated for 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 side corners of the same side stretching position of the electrode assembly are subjected to the same force and deformed in a consistent manner, so that the fold is centered, and the electrode assemblies on both sides of the fold are kept at the same length as much 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 change accordingly to the shape change of the outer wall when clamping the outer wall of the electrode assembly, and continuously maintain a certain fit force on the outer wall, which is conducive to shaping the shape of the outer wall after bending. Since the first plastic molding surface will undergo a certain degree of plastic deformation, an expansion opening is provided on the first plastic molding surface and the expansion joint is connected. This is conducive to the generation of deformation without causing excessive tension after deformation, thereby reducing the triggering force for deformation of the first plastic molding surface and allowing it to change in accordance with the shape of the outer wall of the electrode assembly.

[0008] 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, 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 bending portion formed by stretching the electrode assembly.

[0009] 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 straight 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 electrode assembly at the bending point, achieve the effect of approximately symmetrical bending, and minimize irregular collapse and other deformations at the bending point, effectively ensuring the quality of pre-stretching.

[0010] In an embodiment of the first aspect, the second clamping needle further has an avoidance surface connected to the second molding surface, the avoidance surface is located on the side of the second molding surface away from the first clamping needle for matching clamping and is used to avoid the inner wall surface of the electrode assembly.

[0011] The effect of this embodiment is that an avoidance surface is provided, which increases the distance between the surface of the second clamping needle and the inner wall of the electrode assembly, so that when the second clamping needle withdraws from the inner circle, the possibility of contact with the inner wall of the electrode assembly can be reduced, without destroying the pre-formed shape of the electrode assembly.

[0012] In an embodiment of the first aspect, in the same group of the clamping needle assemblies, in the direction where the first clamping needle points to the second clamping needle, the second molding surface forms a projection area, and the avoidance surface is within the projection area.

[0013] The effect of this embodiment is that the avoidance surface will not exceed the range of the projection area in the direction perpendicular to the direction in which the first clamping needle points to the second clamping needle. This is equivalent to having the support of the second molding surface, so that the avoidance surface will not contact the inner wall of the electrode assembly.

[0014] In one embodiment of the first aspect, the cross section of the second clamping needle perpendicular to its length direction is a teardrop shape. The teardrop shape has the avoidance surface, which can prevent other surfaces of the second clamping needle from contacting the inner wall of the electrode assembly.

[0015] In an embodiment of the first aspect, the telescopic opening is located in the middle of the first molding surface along the width direction, so that the first molding surface maintains a good symmetrical shape, which is conducive to molding the outer wall of the electrode assembly.

[0016] In an embodiment of the first aspect, an avoidance groove is provided at one end of the first clamping needle for setting the clamping portion, and the end of the clamping portion facing away from the second clamping needle is arranged opposite to the notch of the avoidance groove.

[0017] The effect of this embodiment is that the provision of the avoidance groove removes the obstacle to the deformation of the clamping part, allowing it to deform smoothly.

[0018] In an embodiment of the first aspect, the feeding device also includes a first driving mechanism, which is drivingly connected to at least one of the first clamping needle and the second clamping needle of the same group of the clamping needle assembly, and the first driving mechanism is used to drive the corresponding first clamping needle and / or the second clamping needle to approach or move away from the electrode assembly to clamp or release the electrode assembly.

[0019] The effect of this embodiment is that a first driving mechanism is provided, which operates stably and can realize the relative movement of the first clamping needle and the second clamping needle.

[0020] In an embodiment of the first aspect, the feeding device also includes two second driving mechanisms, and the two second driving mechanisms are respectively connected to a group of the clamping needle assemblies, and the second driving mechanisms are used to drive the clamping needle assemblies to move closer to or away from each other to stretch the electrode assembly. The second driving mechanism is also used to drive the clamping needle assembly to make the second clamping needle enter or exit the inner side of the electrode assembly.

[0021] The effect of this embodiment is that the two clamping needle assemblies can realize independent movement, approach or move away from each other, thereby stretching the electrode assembly, and can also enable the second clamping needle of each clamping needle assembly to penetrate into or out of the inner side of the electrode assembly.

[0022] In an embodiment of the first aspect, the first driving mechanism comprises: a second movable seat, on which the first clamping needle is disposed; and A second screw mechanism drives the second movable seat to move so that the first clamping needle approaches or moves away from the second clamping needle.

[0023] In an embodiment of the first aspect, the second driving mechanism comprises: a first movable seat, on which the second screw mechanism, the second movable seat and the second clamping needle are arranged; and The first screw mechanism is used to drive the first moving seat to make the two clamping needle assemblies approach or move away from each other and to make the second clamping needle enter or exit the inner side of the electrode assembly.

[0024] The effect of this embodiment is that the structural form of the driving mechanism can adaptively drive the first clamping needle and the second clamping needle to respectively drive the action, thereby completing the material removal and stretching action of the electrode assembly, and the structure is stable and easy to operate.

[0025] In an embodiment of the first aspect, the first clamping needle is connected to the second movable seat through one end, and the second clamping needle is connected to the first movable seat through one end, and the first clamping needle and the second clamping needle are both arranged in the form of cantilevers and are on the same plane.

[0026] The effect of this embodiment is that the first clamping needle and the second clamping needle arranged in the cantilever form can easily contact the electrode assembly, preventing the structure connecting the first clamping needle and the second clamping needle from touching the electrode assembly.

[0027] In a second aspect, the present application provides a method for cutting a wound electrode assembly, comprising: Using the unloading device for the wound electrode assembly provided in any one of the embodiments, the two second clamping needles of the two clamping needle assemblies are respectively abutted against the inner walls of the two opposite radial sides of the electrode assembly along the first direction, and the two first clamping needles of the two clamping needle assemblies are respectively abutted against the outer walls of the two opposite radial sides of the electrode assembly along the first direction, so that the two groups of clamping needle assemblies clamp the two opposite side portions of the electrode assembly along the first direction; causing a winding needle for winding the electrode assembly to withdraw from the electrode assembly; driving the two groups of the clamping needle assemblies to move backwards along the first direction to stretch the electrode assembly; The first clamping needle and the second clamping needle are separated from the electrode assembly respectively. The operation method realizes the material collection and stretching of the electrode assembly, and the operation is simple and convenient with high efficiency.

[0028] 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 radially opposite side portions of the electrode assembly along the first direction, it also includes: moving the two second clamping needles one by one to be inserted into the slots of the two winding needles.

[0029] The effect of this embodiment is that the length direction of the notch is used as the insertion direction of the second clamping needle, which 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 clamping positions are also symmetrical. In the next step of stretching the electrode assembly, the electrode assembly can also be stretched symmetrically, which is also conducive to the withdrawal of the winding needle.

[0030] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application; Figure 2 A schematic diagram of the structure of a battery device provided in some embodiments of the present application; Figure 3 A schematic diagram of the structure of a needle clamping assembly provided in some embodiments of the present application; Figure 4 for Figure 3 A schematic diagram of the structure when the middle clamping needle assembly clamps the stretched electrode assembly; Figure 5 A schematic diagram of the structure of a clamping needle assembly clamping an electrode assembly wound on a winding needle provided in some embodiments of the present application; Figure 6 for Figure 5 A schematic diagram of the structure of the middle clamp needle assembly stretching the electrode assembly; Figure 7 for Figure 5 A schematic diagram of the structure of the first clamping needle; Figure 8 A schematic structural diagram of a feeding device for a wound electrode assembly provided in some embodiments of the present application; Fig. 9 for Figure 8 A schematic diagram of a top view structure; Fig.10 for Figure 8 A schematic diagram of the structure of the first clamping needle; Fig.11 for Figure 8 Schematic diagram of the structure of the second clamping needle.

[0033] The reference numerals in the specific implementation manner are as follows: 1000. Vehicles; 100, battery device; 200, controller; 300, motor; 1. clamping needle assembly; 11. first clamping needle; 111. first molding surface; 112. clamping portion; 113. expansion joint; 114. avoidance groove; 115. expansion opening; 12. second clamping needle; 121. second molding surface; 122. avoidance surface; 2. Electrode assembly; 3. First driving mechanism; 31. First moving seat; 32. Second moving seat; 33. Second screw mechanism; 4. Rolling needle; 41. Notch. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0036] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0037] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] 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 may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] In the description of the embodiments of the present application, the technical 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0041] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of 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 the specific circumstances.

[0042] At present, from the perspective of market development, the application of battery devices is becoming more and more extensive. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of battery application fields, its market demand is also constantly expanding.

[0043] The battery device is a complete structural unit, including a box body, and multiple battery cells are arranged inside the box body. In some special scenarios, one battery cell can also be arranged inside the box body. When there are multiple battery cells, the battery cells in the same row can be formed into a battery cell assembly.

[0044] like Figure 2 The 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, in parallel, or in hybrid connection through a busbar component, wherein the hybrid connection refers to a mixture of series connection and parallel connection.

[0045] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0046] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0047] In some embodiments, the battery device 100 may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0048] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0049] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0050] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0051] As an example, the box body may 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.

[0052] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0053] The embodiment of the present application further provides an electrical device having the battery device 100 , that is, an electrical device using the battery device 100 as a power source.

[0054] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using the battery device 100, wherein the electrical devices may be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. The spacecraft includes airplanes, rockets, space shuttles, and spacecrafts, etc. The electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. The electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0055] The battery device 100 disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships, or aircraft. The electrical device can use a power supply system having the battery device 100 disclosed in the present application, which is conducive to improving the reliability of the electrical device.

[0056] For the convenience of description, the following embodiments are described by taking the electric device provided in the embodiments of the present application as a vehicle as an example.

[0057] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 may be used to power the vehicle 1000, for example, the battery device 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0058] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0059] The battery cell of the battery device 100 is an energy storage component that can perform charge and discharge reactions. Inside the battery cell is an electrode assembly 2, which includes positive and negative electrode sheets and a separator. The positive and negative electrode sheets and the separator can be placed in the form of stacked sheets or in a wound form. When arranged in a wound form, the electrode assembly 2 is flat.

[0060] During the preparation of the wound electrode assembly 2, the positive and negative electrode sheets and the diaphragm are first wound on the winding needle 4. At this time, the wound electrode assembly 2 is similar to the outer contour of the winding needle 4, and is approximately a circular ring. After the winding is completed, 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 a clamping needle, and the electrode assembly 2 needs to be pre-stretched by the clamping needle, that is, the electrode assembly 2 is stretched from a circular ring to a flat state to facilitate the subsequent extrusion process.

[0061] The clamping needle in the related technology has poor control effect on the shape of the bent part and the crease formed at the stretching position when pre-stretching the electrode assembly, resulting in the electrode assembly having different lengths on both sides of the crease, asymmetric shapes, and prone to wrinkling, which directly affects the forming quality of the electrode assembly in the subsequent extrusion process.

[0062] Based on this, see Figure 3-Figure 11 The present application provides a material feeding device for a wound electrode assembly, which is intended to improve the forming quality of the electrode assembly 2 during pre-stretching. The device comprises two sets of clamping needle assemblies 1, wherein the clamping needle assemblies 1 comprise: The first clamping needle 11 and the second clamping needle 12 are arranged at intervals, the first clamping needle 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, the second clamping needle 12 is used to be placed on the inside of the electrode assembly 2 and clamp the inner wall of the electrode assembly 2, the first clamping needle 11 and the second clamping needle 12 of one group of clamping needle assemblies 1 cooperate with each other to clamp one side of the electrode assembly 2 in the radial direction, and the first clamping needle 11 and the second clamping needle 12 of another group of clamping needle 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 needle assemblies 1 are also used to stretch the electrode assembly 2; Among them, in the same group of clamping needle assemblies 1, the first clamping needle 11 has a first molding surface 111 which is recessed toward one side of the first clamping needle 11 itself, and the shape of the first molding surface 111 is adapted to the shape of the outer wall surface of the electrode assembly 2. The first molding surface 111 is used to fit the outer wall of the electrode assembly 2 to shape the bending portion formed by stretching the electrode assembly 2.

[0063] The clamping needle assembly 1 provided in the embodiment of the present application includes a first clamping needle 11 and a second clamping needle 12. The first clamping needle 11 and the second clamping needle 12 cooperate with each other to clamp the electrode assembly 2 arranged in a wound form. The first clamping needle 11 is used to clamp the outer wall of the electrode assembly 2, and the second clamping needle 12 clamps the inner wall of the electrode assembly 2 at a position corresponding to the first clamping needle 11. The first clamping needle 11 and the second clamping needle 12 in the same clamping needle assembly 1 are used to move synchronously and cooperate with another clamping needle assembly 1 that moves in the opposite direction and clamps the electrode assembly 2 at a symmetrical position to stretch the electrode assembly 2; the first clamping needle 11 has a concave first molding surface 111, and the first molding surface 111 can be a straight cylindrical surface. The first clamping needle 11 clamps the outer wall of the electrode assembly 2 through the first molding surface 111, and the first molding surface 111 is used to fit the outer wall of the electrode assembly 2 to shape the bending portion formed by stretching the electrode assembly 2.

[0064] Specifically, the first clamping needle 11 and the second clamping needle 12 are in a matching relationship, and both clamp the electrode assembly 2 together. Specifically, the first clamping needle 11 is used to clamp the outer wall of the electrode assembly 2, and the second clamping needle 12 cooperates with the first clamping needle 11 at the corresponding position to clamp the inner wall of the electrode assembly 2, and both clamp the electrode assembly 2 together.

[0065] The purpose of the first clamping needle 11 and the second clamping needle 12 clamping the electrode assembly 2 is to remove the electrode assembly 2 wound on the winding needle 4, and to stretch the electrode assembly 2 after removal, that is, to pre-stretch it so that it is initially changed from a circular ring shape to a flat shape. The specific implementation form is that in the process of picking up and stretching, the two clamping needle assemblies 1 need to cooperate with each other, that is, the first clamping needle 11 and the second clamping needle 12 of one clamping needle assembly 1 clamp one part of the electrode assembly 2, and the first clamping needle 11 and the second clamping needle 12 of the other clamping needle assembly 1 clamp another part of the electrode assembly 2. The two positions can be symmetrical positions. After clamping, the winding needle 4 is withdrawn to complete the material picking. After the material picking is completed, the two clamping needle assemblies 1 move away from each other, so as to pre-stretch the electrode assembly 2. The second clamping needle 12 is located at the inner wall of the electrode assembly 2, and can contact the electrode assembly 2 from the inner wall by inserting into the notch 41 of the winding needle 4.

[0066] In the related technology, the surface of the electrode assembly contacted by the clamping needle cannot apply bending elastic deformation force to the positive and negative electrode materials that are deformed at the corners of the electrode assembly after stretching during the stretching process, resulting in different forces on the electrode sheets at the two side corners of the stretching position on the same side of the electrode assembly during the stretching process. After plastic deformation, the crease positions are different and cannot be overlapped, which will cause the inner circle crease position to be lifted up, resulting in inconsistent lengths of the two sides of the crease of the electrode assembly after stretching, resulting in wrinkles or increased spacing between layers, and local deformation exceeding the specification, which directly affects the molding quality of the subsequent extrusion process.

[0067] Based on this, the present 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 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 when it is stretched and bent, it can rely on the first molding surface 111 to form an approximately symmetrical bend, 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 crease is centered, and the electrode assemblies 2 on both sides of the crease are kept at the same length as much as possible without generating wrinkles, thereby improving the pre-stretching forming quality.

[0068] The right cylindrical surface is a part of the cylindrical surface, which is an arc-shaped surface and symmetrical, 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, so that the electrode assembly 2 can be bent approximately symmetrically.

[0069] In some embodiments, see Figure 3 and Figure 4 as well as Fig.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, and 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.

[0070] The second molding surface 121 may also be a straight 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 bending portion formed by stretching the electrode assembly 2.

[0071] 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 straight cylindrical surface of the second clamping needle 12 is smaller than the radius of the straight cylindrical surface of the first clamping needle 11.

[0072] 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.

[0073] Therefore, the effect of this embodiment is that the second molding surface 121 where the second clamping needle 12 contacts the inner wall of the electrode assembly 2 is also designed to be compatible with 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 molding surface support, which can further ensure the molding shape of the electrode assembly 2 at the bending point, achieve the effect of approximately symmetrical bending, and avoid irregular collapse and other deformations at the bending point as much as possible, effectively ensuring the quality of pre-stretching.

[0074] In some embodiments, see Figure 3 and Figure 4 as well as Fig.11 The second clamping needle 12 also has an avoidance surface 122 connected to the second molding surface 121. The avoidance surface 122 is located on the side of the second molding surface 121 away from the first clamping needle 11 and is used to avoid the inner wall surface of the electrode assembly 2.

[0075] The other surfaces of the second clamping needle 12 except the second molding surface 121 include an avoidance surface 122 . The avoidance surface 122 may be a surface inclined toward a side away from the inner wall of the electrode assembly 2 .

[0076] Specifically, the second clamping needle 12 is located at the inner wall of the electrode assembly 2, that is, it is inserted into the circular ring of the electrode assembly 2. After the electrode assembly 2 is stretched to be flat, before the electrode assembly 2 is subjected to the extrusion process, the second clamping needle 12 and the first clamping needle 11 need to be separated from the electrode assembly 2, that is, the second clamping needle 12 at the inner circle is withdrawn from the inner circle. During this process, since the electrode assembly 2 is in a pre-flattened state, it may contact with the inner wall and generate friction when withdrawing, causing deformation of the electrode assembly 2. Therefore, this embodiment provides other surfaces besides the second molding surface 121, including the avoidance surface 122.

[0077] The avoidance surface 122 may be an inclined surface, which is inclined toward a side away from the inner wall of the electrode assembly 2 .

[0078] The effect of this embodiment is that the avoidance surface 122 is set to increase the distance between the surface of the second clamping needle 12 and the inner wall of the electrode assembly 2, so that when the second clamping needle 12 withdraws from the inner circle, the possibility of contact with the inner wall of the electrode assembly 2 can be reduced without destroying the pre-formed shape of the electrode assembly 2.

[0079] In some embodiments, in the same group of clamping needle assemblies 1, in the direction in which the first clamping needle 11 points to the second clamping needle 12, the second molding surface 121 forms a projection area, and the avoidance surface 122 is within the projection area.

[0080] 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 a 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.

[0081] In some embodiments, the cross section of the second clamping needle 12 is in the shape of a water droplet, and the water droplet 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 .

[0082] In some embodiments, see Figure 5-Figure 7 as well as Fig.10 A flexible clamping portion 112 is provided at one end of the first clamping needle 11 facing the second clamping needle 12, and the first molding surface 111 is a flexible surface provided on the clamping portion 112, and 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.

[0083] 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 can remain in contact with the outer wall for molding when the outer wall of the electrode assembly 2 is squeezed.

[0084] Specifically, during the stretching process of the electrode assembly 2, the second clamping needle 12 is used to push the inner wall of the electrode assembly 2, so that the inner wall is attached to the second molding surface 121 and can form the shape of the second molding surface 121. The first clamping needle 11 does not push directly during the movement, but rather supports the electrode assembly 2, because during the stretching, the first clamping needle 11 is in a retreating state and the second clamping needle 12 is in a pushing state. Therefore, for the outer wall of the electrode assembly 2, its fit with the first molding surface 111 of the first clamping needle 11 is not very tight.

[0085] To address this situation, the present 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 and has a certain degree of plastic deformability. Plastic deformation means that a certain degree of deformation can occur and the shape can be restored to the original shape.

[0086] like Figure 5 and Figure 6 Before the electrode assembly 2 is stretched, the outer wall of the electrode assembly 2 first fits the two ends of the first molding surface 111. Because the arc radius corresponding to the first molding surface 111 is smaller than the arc radius of the electrode assembly 2, the outer wall of the electrode assembly 2 first contacts the two ends of the first molding surface 111, but does not fit the central area of ​​the first molding surface 111. Figure 5 After the winding needle 4 is withdrawn and the electrode assembly 2 is stretched, the clamping portion 112 begins to deform under the extrusion force on both ends, and the arc of the first molding surface 111 is expanded by deformation, which is equivalent to increasing the arc radius of the first molding surface 111, so that it can completely fit the outer wall of the electrode assembly 2, thereby shaping the outer wall. As the stretching continues, the arc radius of the outer wall of the electrode assembly 2 becomes smaller, and the arc radius of the first molding surface 111 also becomes smaller, that is, it still maintains a good fit state, and the outer wall is molded.

[0087] Therefore, the effect of this embodiment is that the clamping portion 112 of the first molding surface 111 is set to a flexible material, which can change accordingly to the shape change of the outer wall when clamping the outer wall of the electrode assembly 2, and continuously maintain a certain fitting force to the outer wall, which is conducive to the shaping of the shape of the outer wall after bending.

[0088] In some embodiments, see Figure 7 and Fig.10The first molding surface 111 has a telescopic opening 115 extending along its length direction, and the clamping portion 112 is provided with an expansion joint 113 at a position corresponding to the telescopic opening 115 , and the expansion joint 113 passes through the telescopic opening 115 .

[0089] Specifically, the expansion opening 115 is provided on the first molding surface 111 , and the expansion joint 113 is provided on the clamping portion 112 , and the two are connected.

[0090] Specifically, since the first molding surface 111 will undergo a certain degree of plastic deformation, an expansion opening 115 is provided on the first molding surface 111 and connected to the expansion joint 113, which is conducive to the generation of deformation without causing excessive tension after deformation, thereby reducing the triggering force for the deformation of the first molding surface 111 and allowing it to change in accordance with the shape of the outer wall of the electrode assembly 2.

[0091] The first molding surface 111 has a certain length, which is the length direction of the electrode assembly 2. The expansion joint 113 is opened along the length direction to facilitate the overall expansion and contraction deformation.

[0092] In some embodiments, the telescopic opening 115 is located in the middle of the first molding surface 111 along the width direction.

[0093] The width direction of the first molding surface 111 is perpendicular to the length direction. When the telescopic opening 115 is located in the middle of the width direction, the parts on both sides of the telescopic opening 115 can be symmetrically deformed, so that the first molding surface 111 maintains a good symmetrical shape, which is beneficial to the molding of the outer wall of the electrode assembly 2.

[0094] In some embodiments, see Figure 7 and Fig.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 arranged opposite to the notch 41 of the avoidance groove 114 .

[0095] Specifically, the clamping portion 112 will deform, and when the arc radius of the first plastic surface 111 increases, the expansion joint 113 will expand, and when it decreases, the expansion joint 113 will shrink. When the expansion joint 113 shrinks, the side of the clamping portion 112 opposite to the first plastic surface 111 will bulge toward the avoidance groove 114 when the expansion joint 113 shrinks. The function of the avoidance groove 114 is to avoid the protruding part so that the deformation occurs smoothly.

[0096] The effect of this embodiment is that the provision of the avoidance groove 114 removes the obstacle to the deformation of the clamping portion 112, allowing it to deform smoothly.

[0097] In some embodiments, see Figure 8 and Fig. 9The blanking device also includes a first driving mechanism 3, which is drivingly connected to at least one of the first clamping needle 11 and the second clamping needle 12 of the same group 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.

[0098] This embodiment provides a first driving mechanism 3, and each group 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, and can also be used to drive the second clamping needle 12 to move, and can also drive both to move at the same time, with the purpose of making the two move away from or closer to each other, thereby clamping or releasing the electrode assembly 2.

[0099] The effect of this embodiment is that a first driving mechanism 3 is provided, which operates stably and can realize the relative movement of the first clamping needle 11 and the second clamping needle 12.

[0100] In some embodiments, see Figure 8 and Fig. 9 The feeding device also includes two second driving mechanisms, which are respectively connected to a group of clamping needle assemblies 1. The second driving mechanisms are used to drive the clamping needle assemblies 1 to move closer to or away from each other to stretch the electrode assembly 2. The second driving mechanisms are also used to drive the clamping needle assemblies 1 to make the second clamping needles 12 enter or exit the inner side of the electrode assembly 2.

[0101] Specifically, this embodiment provides a second driving mechanism, which has two, each corresponding to a driving connection of a needle clamping assembly 1.

[0102] The effect of this embodiment is that the two clamping needle assemblies 1 can achieve independent movement, approach or move away from each other, thereby stretching the electrode assembly 2, and can also enable the second clamping needle 12 of each clamping needle assembly 1 to penetrate into or out of the inner side of the electrode assembly 2.

[0103] In some embodiments, see Figure 8 and Fig. 9 , the first driving mechanism 3 comprises: A second movable seat 32, on which a first clamping needle 11 is disposed; and The second screw mechanism 33 drives the second movable seat 32 to move so that the first clamping needle 11 approaches or moves away from the second clamping needle 12.

[0104] The second driving mechanism comprises: A first movable seat 31, on which the second screw mechanism 33, the second movable seat 32 and the second clamping needle 12 are disposed; and The first screw mechanism is used to drive the first movable seat 31 to make the two clamping needle assemblies 1 approach or move away from each other and make the second clamping needle 12 enter or exit the inner side of the electrode assembly 2.

[0105] The first movable seat 31 can move along a preset direction, so that the second clamping needle 12 can move in the preset direction, so that the second clamping needle 12 can complete the action of inserting into the slot 41 of the winding needle 4, contacting the inner wall of the electrode assembly 2, and stretching the electrode assembly 2.

[0106] When the first moving seat 31 moves, the second moving seat 32 moves accordingly, but the second moving seat 32 can also move independently on the first moving seat 31 relative to the first moving seat 31, which is equivalent to the first clamping pin 11 not only moving with the first moving seat 31, but also being able to move relative to the first moving seat 31. For example, when the second clamping pin 12 needs to be inserted into the notch 41 of the winding 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. When the second clamping pin 12 is in place, the first clamping pin 11 can move close to the second clamping pin 12, that is, close to the electrode assembly 2, by means of the movement of the second moving seat 32, and contact the outer wall of the electrode assembly 2, and cooperate with the second clamping pin 12 to clamp the electrode assembly 2. When the electrode assembly 2 is stretched, the first moving seat 31 moves as a whole, driving the first clamping pin 11 and the second clamping pin 12 to move synchronously, thereby stretching the electrode assembly 2.

[0107] The effect of this embodiment is that the structural form of the driving mechanism can adaptively drive the first clamping needle 11 and the second clamping needle 12 to act respectively, thereby completing the material removal and stretching action of the electrode assembly 2, and the structure is stable and easy to operate.

[0108] Specifically, the first screw mechanism and the second screw mechanism 33 are not limited to having only one set of screw assemblies. For example, the first screw mechanism may include two sets of screw assemblies, each set of screw assemblies can make the first movable seat 31 move along a specific direction, and the two sets of screw assemblies can make it move along two perpendicular directions. The second screw mechanism 33 may have only one set of screw assemblies to move the second movable seat 32, thereby driving the first clamping needle 11 to approach or move away from the second clamping needle 12.

[0109] When the first screw mechanism includes two sets of screw assemblies, the nut of the first screw assembly is connected to the second screw assembly, so that the second screw assembly moves in one direction, and the nut of the second screw assembly is connected to the first movable seat 31, so that the first movable seat 31 moves in a second direction. One direction can be the direction in which the first clamping needle 11 approaches and moves away from the second clamping needle 12, that is, the direction in which the electrode assembly 2 is stretched, and the other direction can be the direction in which the second clamping needle 12 is inserted into or withdrawn from the inner side of the electrode assembly 2.

[0110] Therefore, in this embodiment, the first clamping needle 11 and the second clamping needle 12 can be moved by the screw mechanism, and the operation is simple and fast, and the operation is stable.

[0111] In some embodiments, see Figure 9-11 The first clamping needle 11 is connected to the second movable seat 32 through one end, and the second clamping needle 12 is connected to the first movable seat 31 through one end. The first clamping needle 11 and the second clamping needle 12 are both arranged in the form of cantilevers and are on the same plane.

[0112] Specifically, the first clamping needle 11 and the second clamping needle 12 arranged in the cantilever form can conveniently contact the electrode assembly 2, and prevent the structure connecting the first clamping needle 11 and the second clamping needle 12 from touching the electrode assembly 2. For example, when the second clamping needle 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 clamping needle 12. At the same time, the first clamping needle 11 and the second clamping needle 12 are on the same plane, which is also conducive to the stretching of the electrode assembly 2.

[0113] See also Figure 8 and Fig. 9 The present application also provides a method for cutting a wound electrode assembly, using the cutting device for a wound electrode assembly provided in any one of the embodiments, specifically: The two second clamping needles 12 of the two clamping needle assemblies 1 are respectively abutted against the inner walls of the two opposite radial sides of the electrode assembly 2 along the first direction, and the two first clamping needles 11 of the two clamping needle assemblies 1 are respectively abutted against the outer walls of the two opposite radial sides of the electrode assembly 2 along the first direction, so that the two sets of clamping needle assemblies 1 clamp the two opposite side portions of the electrode assembly 2 along the first direction; Allow the winding needle 4 of the wound electrode assembly 2 to withdraw from the electrode assembly 2; Driving the two groups of clamping needle assemblies 1 to move backwards along a first direction to stretch the electrode assembly 2; The first clamping needle 11 and the second clamping needle 12 are separated from the electrode assembly 2 respectively.

[0114] Specifically, this embodiment provides a method for cutting the electrode assembly 2. Specifically, after the winding needle 4 has completed winding the electrode assembly 2, the electrode assembly 2 is wrapped on the surface of the circular winding needle 4 in an annular structure. 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, namely the notch 41.

[0115] In this embodiment, the electrode assembly 2 is fixed by the first clamping needle 11 and the second clamping needle 12 of the two clamping needle assemblies 1 respectively clamping the symmetrical positions of the electrode assembly 2. After fixing, the winding needle 4 is withdrawn, and the electrode assembly 2 is removed, and then the clamping needles of the two clamping needle assemblies 1 move in the opposite direction to achieve stretching.

[0116] During the specific operation, the second clamping needle 12 is first pressed against the inner wall, and then the first clamping needle 11 is pressed against the outer wall. After that, the electrode assembly 2 is fixed and the winding needle 4 can be withdrawn. Then, the two clamping needle assemblies 1 are moved in opposite directions to move away from each other, so that the electrode assembly 2 can be pre-stretched into shape. At this time, the first clamping needle 11 and the second clamping needle 12 can be withdrawn to enter the extrusion process.

[0117] This operation method realizes the material collection and stretching of the electrode assembly 2, and the operation is simple and convenient with high efficiency.

[0118] In some embodiments, before the two second clamping needles 12 of the two clamping needle assemblies 1 are respectively abutted against the inner walls of the two radially opposite sides of the electrode assembly 2 along the first direction, it also includes: moving the two second clamping needles 12 one by one to be inserted into the slots 41 of the two winding needles 4.

[0119] Specifically, the positions of the two second clamping needles 12 are moved so that the two second clamping needles 12 are aligned with the two notches 41 of the winding needle 4 respectively and inserted into the notches 41 by movement, and the second clamping needles 12 are moved again to abut against the inner wall of the electrode assembly 2 .

[0120] The winding needle 4 includes a notch 41 , which is a gap on the winding 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 , thereby clamping the electrode assembly 2 .

[0121] The effect of this embodiment is that the length direction of the notch 41 is used as the insertion direction of the second clamping needle 12, which is equivalent to the notch 41 forming a guide for 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 winding needle 4 includes two notches 41, and the two notches 41 are symmetrical on the winding 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 clamping positions are also symmetrical. In the next step of stretching the electrode assembly 2, the electrode assembly 2 can also be stretched symmetrically, which is also conducive to the withdrawal of the winding needle 4.

[0122] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; 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 included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A feeding device for a wound electrode assembly, characterized in that: It comprises two groups of needle clamping assemblies, wherein the needle clamping assemblies include: A first clamping needle and a second clamping needle are arranged at intervals, the first clamping needle is used to be placed on the outside of the wound electrode assembly and clamp the outer wall of the wound electrode assembly, the second clamping needle is used to be placed on the inside of the electrode assembly and clamp the inner wall of the electrode assembly, the first clamping needle and the second clamping needle of one group 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 another group of the clamping needle assemblies cooperate with each other to clamp another side of the electrode assembly arranged oppositely in the radial direction; the two clamping needle assemblies are also used to stretch the electrode assembly; 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, 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 bending portion formed by stretching the electrode assembly, the first clamping needle faces one end of the second clamping needle and is provided with a flexible clamping portion, the first molding surface is a flexible surface provided on the clamping portion, 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, 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.

2. The unloading device for a wound electrode assembly according to claim 1, characterized in that: 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. The second molding surface is used to fit the inner wall of the electrode assembly to shape the bending portion formed by stretching the electrode assembly.

3. The unloading device for a wound electrode assembly according to claim 2, characterized in that: The second clamping needle also has an avoidance surface connected to the second molding surface. The avoidance surface is located on the side of the second molding surface away from the first clamping needle that is matched to clamp and is used to avoid the inner wall surface of the electrode assembly.

4. The unloading device for a wound electrode assembly according to claim 3, characterized in that: In the same group of the clamping needle assemblies, in the direction where the first clamping needle points to the second clamping needle, the second molding surface forms a projection area, and the avoidance surface is within the projection area.

5. The unloading device for a wound electrode assembly according to claim 3, characterized in that: The cross section of the second clamping needle perpendicular to the length direction thereof is in a teardrop shape.

6. The unloading device for a wound electrode assembly according to claim 1, characterized in that: The telescopic opening is located in the middle of the first molding surface along the width direction.

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

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

9. The unloading device for a wound electrode assembly according to claim 8, characterized in that: The feeding device also includes two second driving mechanisms, which are respectively connected to one group of the clamping needle assemblies. The second driving mechanisms are used to drive the clamping needle assemblies to move closer to or away from each other to stretch the electrode assembly. The second driving mechanism is also used to drive the clamping needle assembly to make the second clamping needle enter or exit the inner side of the electrode assembly.

10. The unloading device for a wound electrode assembly according to claim 9, characterized in that: The first driving mechanism comprises: a second movable seat, on which the first clamping needle is disposed; and A second screw mechanism drives the second movable seat to move so that the first clamping needle approaches or moves away from the second clamping needle.

11. The unloading device for a wound electrode assembly according to claim 10, characterized in that: The second driving mechanism comprises: a first movable seat, on which the second screw mechanism, the second movable seat and the second clamping needle are arranged; and The first screw mechanism is used to drive the first moving seat to make the two clamping needle assemblies approach or move away from each other and to make the second clamping needle enter or exit the inner side of the electrode assembly.

12. The unloading device for a wound electrode assembly according to claim 11, characterized in that: The first clamping needle is connected to the second movable seat through one end, and the second clamping needle is connected to the first movable seat through one end. The first clamping needle and the second clamping needle are both arranged in the form of cantilevers and are on the same plane.

13. A method for cutting a wound electrode assembly, characterized in that: include: Using the unloading device of the wound electrode assembly according to any one of claims 1 to 12, the two second clamping needles of the two clamping needle assemblies are respectively abutted against the inner walls of the two opposite radial sides of the electrode assembly along the first direction, and the two first clamping needles of the two clamping needle assemblies are respectively abutted against the outer walls of the two opposite radial sides of the electrode assembly along the first direction, so that the two groups of clamping needle assemblies clamp the two opposite side portions of the electrode assembly along the first direction; causing a winding needle for winding the electrode assembly to withdraw from the electrode assembly; driving the two groups of the clamping needle assemblies to move backwards along the first direction to stretch the electrode assembly; The first clamping needle and the second clamping needle are separated from the electrode assembly respectively.

14. The method for cutting a wound electrode assembly according to claim 13, wherein: Before making the two second clamping needles of the two clamping needle assemblies respectively abut against the inner walls of the two opposite radial sides of the electrode assembly along the first direction, the method also includes: moving the two second clamping needles one by one to be inserted into the slots of the two winding needles.

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