Cell forming method and battery manufacturing method

Abstract

The present application provides a battery cell forming method and a battery manufacturing method, wherein the battery cell forming method includes: using a clamping device to clamp the battery cell and moving the clamping device along a first direction to stretch the battery cell to a first preset state; and using a clamping device and a pressing device at the same time to deform the battery cell to a second preset state; wherein using a clamping device and a pressing device at the same time to deform the battery cell to the second preset state includes: causing the clamping device to continue to move along the first direction to stretch the battery cell and causing the pressing device to move along the second direction to squeeze the battery cell in the second direction, and the second direction is perpendicular to the first direction. The battery manufacturing method includes the above-mentioned battery cell forming method. The present application first stretches the battery cell to a first preset state, and then combines stretching and squeezing to deform the battery cell to a second preset state, which can avoid wrinkles in the inner circle of the battery cell caused by squeezing the battery cell in only a single direction, and reduce problems such as pole piece tearing that may be caused by excessive single stretching.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery core forming method and a battery manufacturing method. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] Secondary batteries, especially lithium-ion batteries, have the advantages of high voltage, high specific energy, long cycle life, green and pollution-free, wide operating temperature range and low self-discharge. They are widely used in portable electronic devices, energy storage devices and power equipment of large new energy electric vehicles, and are of great significance to solving human environmental pollution and energy crisis. With the widespread application of lithium-ion batteries, the manufacturing method of batteries has become a problem that manufacturers pay close attention to.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] The present application provides a battery core forming method and a battery manufacturing method.

[0006] In a first aspect, the present application provides a battery core forming method, comprising:

[0007] Using a clamping device to clamp the battery cell, and moving the clamping device along a first direction to stretch the battery cell to a first preset state; and

[0008] The clamping device and the pressing device are simultaneously used to deform the battery cell to a second preset state;

[0009] Wherein, the clamping device and the pressing device are simultaneously used to deform the battery cell to a second preset state, including:

[0010] The clamping device is moved continuously along the first direction to stretch the battery cell, and the pressing device is moved along the second direction to press the battery cell in the second direction, wherein the second direction is perpendicular to the first direction.

[0011] After the battery cell is stretched to the first preset state, the battery cell is stretched in the first direction by a clamping device and pressed in the second direction by a pressing device, that is, the battery cell is stretched in the first direction at least twice. The degree of the second stretching can be adjusted based on the shape and structure of the battery cell in the first preset state, thereby facilitating a more precise adjustment of the internal structure of the battery cell and reducing the non-uniformity of the internal structure.

[0012] During the second stretching process, by stretching the battery cell in the first direction and squeezing the battery cell in the second direction at the same time, the shape of the battery cell can be adjusted in two dimensions in the first direction and the second direction, which helps to make the battery cell obtain a shape and size that better meets the design requirements.

[0013] Furthermore, by applying forces to the battery cells in different directions, structural damage inside the battery cells that may be caused by stress concentration in a single direction can be avoided.

[0014] In addition, by squeezing the battery cell in the second direction while stretching the battery cell in the first direction, the wrinkling of the inner circle of the battery cell caused by squeezing the battery cell only in a single direction as in the related art can be effectively avoided, thereby effectively improving the integrity of the final internal structure of the battery cell.

[0015] In some embodiments, the pressing device includes a first pressing portion and a second pressing portion arranged along a second direction, and moving the pressing device along the second direction to press the battery cell in the second direction includes:

[0016] bringing the first pressing portion and the second pressing portion closer together along a second direction; and

[0017] The first pressing portion and the second pressing portion are kept at equal distances from the clamping device.

[0018] By bringing the first pressing part and the second pressing part closer together along the second direction to squeeze the battery cell, it can be ensured that the force applied to the battery cell during the pressing process is always along the second direction, thereby reducing the occurrence of skewness and the like, and helping the battery cell to obtain a more regular geometric shape.

[0019] By making the first pressing part and the second pressing part have equal distances from the clamping device, the clamping device is always located between the first pressing part and the second pressing part, which helps to maintain the shape symmetry of the battery cell in the second direction and improve the molding quality of the battery cell.

[0020] In some embodiments, bringing the first pressing part and the second pressing part closer together along the second direction comprises:

[0021] In the second direction, the first pressing part is kept stationary, and the second pressing part and the clamping device are moved closer to the first pressing part; or

[0022] In the second direction, the second pressing part is kept stationary, and the first pressing part and the clamping device are moved closer to the second pressing part; or

[0023] In the second direction, the clamping device is kept stationary, and the first pressing portion and the second pressing portion are moved closer to the clamping device.

[0024] The mutual operation mode between the first pressing part, the second pressing part and the clamping device can be selected according to actual production conditions.

[0025] In some embodiments, maintaining equal spacing between the first pressing portion and the second pressing portion and the clamping device comprises:

[0026] In the second direction, the second pressing part is kept stationary, the first pressing part is moved toward the second pressing part at a first speed, and the clamping device is moved toward the second pressing part at a second speed, wherein the first speed is twice the second speed; or

[0027] In the second direction, the clamping device is kept stationary, and the first pressing part and the second pressing part are moved toward the clamping device at the same speed.

[0028] Regardless of which moving mode is used in the above embodiments, the deformation process of the battery cell can be controlled by correspondingly setting the movement directions and speeds of the first pressing part, the second pressing part and the clamping device, so that the battery cell obtains a regular shape and a uniform internal structure.

[0029] The specific values ​​of the movement speeds of the first pressing part, the second pressing part or the clamping device can be set according to the specifications, materials and production efficiency requirements of the battery cell. It is sufficient to ensure that the clamping device can always be located in the middle position between the first pressing part and the second pressing part during the pressing process of the battery cell, so that the battery cell can be symmetrically deformed along the second direction.

[0030] In some embodiments, the pressing device includes a first pressing portion and a second pressing portion arranged along a second direction, and moving the pressing device along the second direction to press the battery cell in the second direction includes:

[0031] In the second direction, the second pressing part is kept stationary, and the first pressing part and the clamping device are moved closer to the second pressing part; and

[0032] The distance h between the clamping device and the second pressing part and the distance H between the first pressing part and the second pressing part satisfy a first preset relationship.

[0033] In some embodiments, the first preset relationship includes:

[0034] h / H=(h1-h2) / (H1-H2),

[0035] Among them, h1 is the distance between the clamping device and the second pressing part when the battery cell is in the first preset state, h2 is the distance between the clamping device and the second pressing part when the battery cell is in the second preset state, H1 is the distance between the first pressing part and the second pressing part when the battery cell is in the first preset state, and H2 is the distance between the first pressing part and the second pressing part when the battery cell is in the second preset state.

[0036] The first preset relationship can be a difference relationship, a proportional relationship, etc., so that a certain first preset relationship is maintained between h and H. The purpose is to enable the battery cell to obtain a uniform deformation rate during the pressing process, so as to reduce the local stress concentration phenomenon that may be caused by uneven deformation in the second direction, so that the internal structure of the battery cell can maintain a relatively stable state during the deformation process, which helps to avoid damage to the internal structure of the battery cell.

[0037] In some embodiments, the clamping device includes two groups of clamping assemblies arranged along a first direction, the clamping assemblies include inner clamping pins located radially inwardly of the battery core and outer clamping pins located radially outwardly of the battery core, and the pressing device includes a first pressing portion and a second pressing portion arranged along a second direction, so that the clamping device continues to move along the first direction to stretch the battery core, including:

[0038] The distance L between the two inner clamping needles and the distance H between the first pressing part and the second pressing part satisfy a second preset relationship.

[0039] In some embodiments, the second preset relationship includes:

[0040] L / H=(L2-L1) / (H1-H2),

[0041] Among them, L1 is the distance between the two inner clamping needles when the battery cell is in the first preset state, L2 is the distance between the two inner clamping needles when the battery cell is in the second preset state, H1 is the distance between the first pressing part and the second pressing part when the battery cell is in the first preset state, and H2 is the distance between the first pressing part and the second pressing part when the battery cell is in the second preset state.

[0042] The second preset relationship can be a difference relationship, a proportional relationship, etc., so that a certain second preset relationship is maintained between L and H. The purpose is to ensure that the deformation rate of the battery cell in the first direction and the second direction remains stable during the stretching and pressing process, so as to reduce the local stress concentration phenomenon that may be caused by uneven deformation, improve the distribution uniformity of the internal structure of the battery cell, and improve the molding quality of the final battery cell product.

[0043] In some embodiments, the clamping device includes two groups of clamping components arranged along a first direction, so that the clamping device continues to move along the first direction to stretch the battery cell, including: driving the two groups of clamping components away from each other with a preset driving force F to keep the radial inner side of the battery cell taut.

[0044] By setting a preset driving force F to keep the radial inner side of the battery cell taut, wrinkling problems caused by redundancy can be avoided, so that the inner ring pole pieces and diaphragms can be fully stretched, so that the distance between the cathode and anode pole pieces of the battery cell can also meet the process requirements, which helps to ensure the final molding quality of the battery cell.

[0045] In some embodiments, the preset driving force F is 10-30N.

[0046] In the process of clamping and stretching the battery cell with a clamping device, problems such as excessive local stress or indentation and wrinkles may easily occur due to local clamping, which will in turn affect the molding quality of the battery cell.

[0047] Therefore, during the stretching process of the battery cell, the clamping force of the clamping device can be adjusted in real time according to the shape of the battery cell, and the clamping assembly can even be loosened in time to provide a certain adjustment space for the position of the clamping assembly relative to the battery cell.

[0048] In some embodiments, the clamping device includes two groups of clamping assemblies arranged along a first direction, the clamping assemblies include inner clamping pins located radially inwardly of the battery core and outer clamping pins located radially outwardly of the battery core, and in the process of causing the clamping device to continue to move along the first direction to stretch the battery core,

[0049] Make the two outer clamping pins both in the position to clamp the battery core or in the position to release the clamping of the battery core; or

[0050] One outer clamping pin is placed in a position capable of clamping the battery cell, and the other outer clamping pin is placed in a position to release the clamping of the battery cell.

[0051] When the outer clamping pin is loosened, due to the continued action of the tensile force, the inner clamping pin of the left clamping assembly can achieve a certain sliding relative to the inner ring of the battery cell, thereby automatically adjusting to a position that keeps the inner ring of the battery cell taut, so as to avoid wrinkling problems and allow the inner ring pole piece and diaphragm to be fully stretched.

[0052] In some embodiments, the battery core forming method further comprises:

[0053] After the battery core is stretched to the second preset state by the clamping device and the pressing device at the same time, the clamping device is released from the battery core, and the pressing device is used to press the battery core along the second direction to the third preset state.

[0054] Transforming the battery cell to the third preset state is not limited to the above-mentioned operations. Instead, after deforming the battery cell to the second preset state, the specific operation to be performed can be determined based on observation and judgment of the stretching state of the battery cell's pole piece and diaphragm and the overall shape of the battery cell in actual production.

[0055] In a second aspect, the present application provides a battery manufacturing method, including the above-mentioned battery cell forming method.

[0056] 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

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application 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 the drawings without paying creative work.

[0058] Figure 1 It is a schematic diagram of the state of the deformation process of the battery cell in some embodiments of the battery cell forming method disclosed in the present application.

[0059] Figure 2 It is a schematic diagram of the structure of a pressing device in some embodiments of the battery core forming method disclosed in the present application.

[0060] Figure 3 It is a schematic diagram of the structure of the driving device in some embodiments of the battery core forming method disclosed in this application.

[0061] Figure 4 It is a schematic diagram of the state of the deformation process of the battery cell in other embodiments of the battery cell forming method disclosed in the present application.

[0062] Figure 5 It is a partial structural schematic diagram of a battery cell forming device in other embodiments of the battery cell forming method disclosed in the present application.

[0063] Figure 6 It is a schematic diagram of the state of the deformation process of the battery cell in some embodiments of the battery cell forming method disclosed in the present application.

[0064] In the drawings, the drawings are not drawn to scale.

[0065] Marking Description:

[0066] 100. Battery cell;

[0067] 200, battery cell forming equipment; 201, first pressing part; 202, second pressing part; 203, inner clamping needle; 204, outer clamping needle; 205, first driving member; 206, second driving member; 207, support rod; 208, support plate; 209, third driving member; 210, fourth driving member; 211, fifth driving member; 212, first mounting plate; 213, second mounting plate. DETAILED DESCRIPTION

[0068] 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.

[0069] 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.

[0070] 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 addition, the term "perpendicular" does not mean perpendicular in the strict sense, but is within the allowable error range. "Parallel" does not mean parallel in the strict sense, but is within the allowable error range.

[0071] 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.

[0072] 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.

[0073] In the description of the embodiments of the present application, the term "multiple" refers to more than two, unless otherwise clearly defined. Similarly, "multiple groups" refers to more than two groups, and "multiple sheets" refers to more than two sheets, unless otherwise clearly defined.

[0074] 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.

[0075] 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.

[0076] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries 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 the application field of power batteries, the market demand is also constantly expanding, so the manufacturing method of batteries has become a problem that producers pay close attention to.

[0077] In some related technologies, in order to improve the space utilization and energy density of the battery, the round battery cell needs to be further processed into a square or flat shape. In the process of forming the battery cell from a round shape to a square or flat shape, the stretching control of the internal pole piece and diaphragm is extremely critical. Therefore, how to effectively control the stretching degree of the internal pole piece and diaphragm of the battery cell is one of the difficulties in battery production.

[0078] Generally, a circular battery cell is made of multiple layers of pole pieces (including cathode and anode) and separators stacked and wound alternately. If the battery cell is stretched too much, it may cause the pole piece to crack or rebound after the clamp is released; if it is not stretched enough, it may cause the pole piece to form wrinkles on the inner circle, affecting the gap between the cathode and anode, thus failing to meet the requirements of the battery production process.

[0079] Research has found that when using equipment such as clamps to stretch round cells, if the cell thickness and height are too large, it is difficult to stretch the cell to an ideal square state through the cooperation of the inner and outer clamping pins of the clamp alone, affected by factors such as the stiffness and parallelism of the inner and outer clamping pins of the clamp. After the cell is stretched, the clamping pin releases the cell and pulls it out, and the pre-pressing plate is used to press down to compact the cell into a square. In this process, the pole piece and diaphragm of the inner circle of the cell are difficult to be effectively stretched, and there is a risk of redundant wrinkling of the pole piece, and the distance between the anode and cathode cannot meet the process requirements.

[0080] In view of this, the embodiments of the present application provide a battery cell forming method and a battery manufacturing method, wherein the battery cell is first stretched along a first direction to a first preset state, and then the battery cell is deformed along a second direction to a second preset state by combining stretching and extrusion, thereby adjusting the shape of the battery cell in two dimensions, namely, the first direction and the second direction, so as to effectively control the stretching state of the electrode and the diaphragm inside the battery cell, and reduce the formation of defects such as cracking and wrinkling of the electrode, thereby improving the performance level of the final battery product.

[0081] The battery cell manufactured by the battery cell forming method provided in the embodiment of the present application can be applied to various types of batteries.

[0082] The battery manufactured based on the battery manufacturing method provided in the embodiment of the present application can be applied to various types of electrical devices using batteries. The electrical device can be a mobile phone, a portable device, a laptop computer, a battery car, an electric car, a ship, a spacecraft, an electric toy and an electric tool, etc. For example, a spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc., an electric toy includes a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy and an electric airplane toy, etc., and an electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and an electric tool for railways, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer. The embodiment of the present application does not particularly limit the above-mentioned electrical device. The battery can be used to power electrical devices such as vehicles, for example, to provide a power supply for control of the vehicle or a power supply for driving the vehicle.

[0083] In some embodiments, the battery may include a box and a battery cell, wherein the box is used to provide a storage space for the battery cell, and the battery cell is installed in the box. The number of the battery cell may be one or more.

[0084] In some embodiments, a battery cell includes an electrode assembly, a housing, an end cap, and a current collecting assembly. The housing has a receiving cavity for receiving the electrode assembly and an open end connected to the receiving cavity. The end cap covers the open end. The current collecting assembly is electrically connected to the electrode assembly and the housing to achieve electrical connection between the electrode assembly and the housing.

[0085] In some embodiments, the electrode assembly includes a battery cell. The battery cell may be a battery cell of a wound structure in which a positive electrode sheet, a negative electrode sheet, and a separator are wound, or a battery cell of a stacked structure in which a positive electrode sheet, a negative electrode sheet, and a separator are overlapped. One or more positive electrode sheets and negative electrode sheets may be provided respectively. As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets are alternately provided along the thickness direction of the electrode sheets.

[0086] In some embodiments, the shape of the battery cell can be cylindrical, flat, or polygonal.

[0087] During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing the active ions to pass through.

[0088] In some embodiments, the positive electrode sheet may include a positive current collector substrate and a positive active material layer disposed on at least one surface of the positive current collector substrate.

[0089] As an example, the positive electrode current collector substrate has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector substrate.

[0090] As an example, the positive electrode current collector substrate may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by placing a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0091] As an example, the positive electrode active material layer may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active material layers of batteries may also be used. These positive electrode active material layers may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523), LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.85Co0.15Al0.05O2) and at least one of their modified compounds.

[0092] In some embodiments, the negative electrode sheet may include a negative current collector substrate.

[0093] As an example, the negative electrode current collector substrate can be a metal foil, a foamed metal or a composite current collector. For example, as a metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by placing a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0094] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector substrate.

[0095] As an example, the negative electrode current collector substrate has two surfaces facing each other in its thickness direction, and the negative electrode active material layer is disposed on any one or both of the two facing surfaces of the negative electrode current collector substrate.

[0096] As an example, the negative electrode active material layer may adopt the negative electrode active material layer for battery cells known in the art. As an example, the negative electrode active material layer may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active material layers for batteries may also be used. These negative electrode active material layers may be used alone or in combination of two or more.

[0097] In some embodiments, the material of the positive electrode current collector substrate may be aluminum, and the material of the negative electrode current collector substrate may be copper.

[0098] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0099] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive electrode sheet and the negative electrode sheet, or it can be located between the positive electrode sheet and the negative electrode sheet and attached to the surface of the positive electrode sheet and / or the surface of the negative electrode sheet.

[0100] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet and plays the role of transmitting ions and isolating the positive and negative electrodes.

[0101] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments can be combined with each other.

[0102] According to one aspect of the present application, a battery core forming method is provided, comprising:

[0103] Using a clamping device to clamp the battery cell 100, and moving the clamping device along a first direction to stretch the battery cell 100 to a first preset state; and

[0104] The clamping device and the pressing device are simultaneously used to deform the battery cell 100 to a second preset state;

[0105] The method of simultaneously using the clamping device and the pressing device to deform the battery cell 100 to the second preset state includes:

[0106] The clamping device is continuously moved in the first direction to stretch the battery cell 100 , and the pressing device is moved in the second direction to press the battery cell 100 in the second direction, the second direction being perpendicular to the first direction.

[0107] The first preset state may be an intermediate state before the battery cell 100 reaches the final state. The second preset state may be a state of the battery cell 100 between the first preset state and the final state.

[0108] In the above embodiments, the final support state of the battery cell refers to the state of the battery cell with a predetermined size and shape reached at the end of the stretching process. The specification size of the battery cell in the final support state can be obtained based on the design parameters of the battery cell, that is, in the final support state, the internal electrode and diaphragm of the battery cell have generally been stretched to a size and shape that meets the requirements of the stretching process.

[0109] You can refer to Figure 1 , shows the shape change process of the battery cell 100 from the first preset state to the final forming state (i.e., the final support state) in some embodiments of the present application. Figure 1 The x direction is shown in Figure 1 In some embodiments, the first direction may be a width direction of the battery cell 100 , and the second direction may be a thickness direction of the battery cell 100 .

[0110] Specifically, Figure 1 The first figure from the left shows the battery cell 100 in a first preset state, the third figure from the left shows the battery cell 100 in a second preset state, and the second figure from the left shows any state of the battery cell 100 in the process of changing from the first preset state to the second preset state.

[0111] Alternatively, in other cases, if the battery cell in the second preset state has been stretched to a size and shape that meets the stretching process requirements, the second preset state may also be defined as the final support state of the battery cell 100 .

[0112] Specifically, it can be set that in the first preset state, the width of the battery cell 100 is 60%, 70% or 80% of the width in the final support state. It can also be set that in the second preset state, the width of the battery cell 100 is 80%, 90% or 100% of the width in the final support state. It can be set according to actual production needs.

[0113] After the battery cell 100 is deformed to the second preset state, whether to further stretch, extrude or perform other forming operations on the battery cell 100 can be determined based on the observation and judgment of the stretching state of the electrode and diaphragm in the battery cell 100 and the overall shape of the battery cell 100 in actual production.

[0114] In the above embodiment, the battery cell 100 is stretched to a first preset state along a first direction by using a clamping device, and the size, shape and other parameters that the battery cell 100 should meet in the first state are appropriately set, so that the stretching degree of the electrode and the diaphragm inside the battery cell 100 can be effectively controlled.

[0115] In the embodiment of the present application, after the battery cell 100 is stretched to the above-mentioned first preset state, the battery cell 100 is stretched in a first direction (for example, a transverse or horizontal direction) by a clamping device and pressed in a second direction (for example, a longitudinal or vertical direction) by a pressing device, that is, the battery cell 100 is stretched in the first direction at least twice. The degree of the second stretching can be adjusted based on the shape and structure of the battery cell 100 in the first preset state, so as to help more finely adjust the internal structure of the battery cell 100 and reduce the unevenness of the internal structure.

[0116] During the second stretching process, by stretching the battery cell 100 in the first direction and squeezing the battery cell 100 in the second direction at the same time, the shape of the battery cell 100 can be adjusted synchronously in two dimensions, the first direction and the second direction, which helps to make the battery cell 100 obtain a shape and size that better meets the design requirements.

[0117] Furthermore, by applying forces to the battery cell 100 in different directions, structural damage inside the battery cell 100 that may be caused by stress concentration in a single direction can be avoided.

[0118] In addition, by squeezing the battery cell 100 in the second direction and stretching the battery cell 100 in the first direction at the same time, the wrinkling phenomenon of the inner circle of the battery cell caused by squeezing the battery cell only in a single direction as in the related art can be effectively avoided, thereby effectively improving the integrity of the internal structure of the final battery cell.

[0119] Compared with the operation of stretching the battery cell once to achieve forming in the related art, the operation method of the present application of first stretching the battery cell to a first preset state and then combining stretching and extrusion to deform the battery cell to a second preset state can effectively reduce problems such as electrode tearing or rebound after stretching that may be caused by excessive single stretching.

[0120] Furthermore, for the equipment used to implement battery cell molding, such a molding method of applying force to the battery cell 100 in two directions can effectively reduce the load of the equipment in any direction, thereby helping to extend the service life of the relevant equipment.

[0121] In the above embodiment, both the first direction and the second direction are perpendicular to the axial direction of the battery cell 100 .

[0122] In actual application, the forming process of the battery cell 100 is not limited to the above-mentioned stretching, re-stretching and extrusion. Instead, whether to continue further stretching or extrusion operations can be considered based on the state reached by the battery cell 100 after each deformation and factors such as production efficiency, so that the battery cell 100 finally obtains a stable and uniform structure that meets the process requirements.

[0123] In some embodiments, the pressing device includes a first pressing portion 201 and a second pressing portion 202 arranged along a second direction, and moving the pressing device along the second direction to press the battery cell 100 in the second direction includes:

[0124] The first pressing part 201 and the second pressing part 202 are brought closer together along the second direction; and

[0125] The first pressing part 201 and the second pressing part 202 are kept at equal distances from the clamping device.

[0126] The battery cell 100 is squeezed by bringing the first pressing part 201 and the second pressing part 202 closer together in the second direction, ensuring that the force applied to the battery cell 100 is always in the second direction during the pressing process, thereby reducing the occurrence of skewness of the battery cell 100 during deformation, and helping to make the battery cell 100 obtain a more regular geometric shape.

[0127] By further controlling the movement parameters of the first pressing part 201 and the second pressing part 202, such as displacement and speed, the deformation speed of the battery cell 100 and the thickness that can be achieved after deformation can be controlled, thereby ensuring that the battery cell 100 can be stably deformed and reach a preset thickness that meets design requirements.

[0128] The first pressing part 201 and the second pressing part 202 are kept at an equal distance from the clamping device, that is, the clamping device is always located between the first pressing part 201 and the second pressing part 202. In this case, the pressure exerted by the pressing parts on the structures of the battery cell 100 located on both sides of the clamping device is symmetrical, which helps to maintain the shape symmetry of the battery cell 100 in the second direction and improve the molding quality of the battery cell 100.

[0129] The relative movement form between the first pressing part 201, the second pressing part 202 and the clamping device can be selected according to actual production conditions.

[0130] For example, in some embodiments, the operation of bringing the first pressing part 201 and the second pressing part 202 closer together along the second direction includes: in the second direction, keeping the first pressing part 201 stationary, and bringing the second pressing part 202 and the clamping device closer to the first pressing part 201 .

[0131] Alternatively, in other embodiments, the operation of bringing the first pressing part 201 and the second pressing part 202 closer together along the second direction includes: in the second direction, keeping the second pressing part 202 stationary, and bringing the first pressing part 201 and the clamping device closer to the second pressing part 202 .

[0132] The method of moving one of the pressing parts to move the clamping device and the other pressing part closer to the immobile pressing part by keeping one of the pressing parts stationary only requires the clamping device and the pressing part to be moved to be controlled to move in the same direction, which is simple to operate and helps to simplify the control process. In addition, for a production line that needs to produce multiple battery cells, in this case, the pressing part that does not move in the second direction can be set as a conveyor belt with a conveying direction along the first direction, so that after completing the pressing process of each battery cell, it can be quickly transported to the next production process.

[0133] For details, please refer to Figure 2 As shown, in some embodiments, the first pressing part 201 is configured as a pressing plate, the second pressing part 202 is configured as a conveyor belt, the conveyor belt is configured to move along a first direction to transport the battery cell 100, and the first driving member 205 is configured to drive the pressing plate to move along a second direction toward the conveyor belt, thereby squeezing the battery cell 100.

[0134] The first driving member 205 may adopt a variety of optional structural forms such as a motor and a hydraulic cylinder.

[0135] In addition, refer to Figure 3 As shown, a driving device can be provided to drive the clamping device to move in the second direction. The driving device includes a second driving member 206, a support rod 207 and a support plate 208. The support rod 207 is arranged perpendicular to the conveying plane of the conveyor belt, and the clamping device is installed on the support plate 208. By the second driving member 206 driving the support plate 208 to move along the support rod 207 in the direction close to the conveyor belt, the clamping device can be synchronously driven to move toward the conveyor belt.

[0136] Alternatively, in some other embodiments, the operation of bringing the first pressing part 201 and the second pressing part 202 closer together along the second direction includes: in the second direction, keeping the clamping device stationary, and bringing the first pressing part 201 and the second pressing part 202 closer to the clamping device.

[0137] The method of keeping the clamping device stationary and moving the first pressing part 201 and the second pressing part 202 toward the clamping device along the second direction to squeeze the battery cell 100 can make the squeezing of the battery cell 100 from the first pressing part 201 and the second pressing part 202 symmetrical, that is, the structure of the battery cell 100 distributed on both sides of the clamping device can obtain a consistent amount of deformation, which helps to make the battery cell 100 obtain a more uniform and stable shape. In addition, there is no need to adjust the position of the battery cell 100 in this process, and the first pressing part 201 and the second pressing part 202 move toward each other, which has a high squeezing efficiency for the battery cell 100, which can not only ensure the position accuracy of the battery cell 100 during the squeezing process, but also effectively improve the production efficiency.

[0138] Regardless of the moving mode used in the above embodiments, the deformation process of the battery cell 100 can be controlled by correspondingly controlling the movement direction and speed of the first pressing part 201, the second pressing part 202 and the clamping device, so that the battery cell 100 obtains a regular shape and a uniform internal structure.

[0139] Specifically, in some embodiments, the first pressing part 201 and the second pressing part 202 are kept at equal distances from the clamping device, including:

[0140] In the second direction, the second pressing part 202 is kept stationary, the first pressing part 201 is moved toward the second pressing part 202 at a first speed, and the clamping device is moved toward the second pressing part 202 at a second speed, wherein the first speed is twice the second speed; or

[0141] In the second direction, the clamping device is kept stationary, and the first pressing part 201 and the second pressing part 202 are moved toward the clamping device at the same speed.

[0142] The specific values ​​of the movement speeds of the first pressing part 201, the second pressing part 202 or the clamping device can be set according to the specifications, materials and production efficiency requirements of the battery cell. It is sufficient to ensure that the clamping device can always be located in the middle position between the first pressing part 201 and the second pressing part 202 during the pressing process of the battery cell 100, so that the battery cell 100 can be symmetrically deformed along the second direction.

[0143] The pressing process of the battery cell 100 can be controlled by setting the movement speed of the first pressing part 201 , the second pressing part 202 or the clamping device, or by controlling the position of the clamping device relative to the first pressing part 201 and the second pressing part 202 .

[0144] In some embodiments, the pressing device includes a first pressing portion 201 and a second pressing portion 202 arranged along a second direction, and moving the pressing device along the second direction to press the battery cell 100 in the second direction includes:

[0145] In the second direction, the second pressing part 202 is kept stationary, and the first pressing part 201 and the clamping device are moved closer to the second pressing part 202; and

[0146] The distance h between the clamping device and the second pressing part 202 and the distance H between the first pressing part 201 and the second pressing part 202 satisfy a first preset relationship.

[0147] h represents the distance between the clamping device and the second pressing portion 202 in any state during the process of the battery cell 100 being deformed from the first preset state to the second preset state, and H represents the distance between the first pressing portion 201 and the second pressing portion 202 in the corresponding state.

[0148] The first preset relationship may be a difference relationship, a proportional relationship, etc. The purpose of maintaining a certain first preset relationship between h and H is to obtain a uniform deformation rate during the pressing process of the battery cell 100, so as to reduce the local stress concentration phenomenon that may be caused by uneven deformation in the second direction. The uniform deformation rate can keep the internal structure of the battery cell 100 in a relatively stable state during the deformation process, which helps to avoid damage to the internal structure of the battery cell 100.

[0149] As an example, see Figure 4 , from left to right, shows the process of the battery cell 100 being deformed from the first preset state to the second preset state in some embodiments of the present application. Among them, h1 is the distance between the clamping device and the second pressing part 202 when the battery cell 100 is in the first preset state, H1 is the distance between the first pressing part 201 and the second pressing part 202 when the battery cell 100 is in the first preset state; h2 is the distance between the clamping device and the second pressing part 202 when the battery cell 100 is in the second preset state, H2 is the distance between the first pressing part 201 and the second pressing part 202 when the battery cell 100 is in the second preset state; h is the distance between the clamping device and the second pressing part 202 in any state during the process of the battery cell 100 being deformed from the first preset state to the second preset state, and H is the distance between the first pressing part 201 and the second pressing part 202 in the corresponding state.

[0150] In some embodiments, the above-mentioned first preset relationship includes: h / H=h1-h2 / H1-H2. Among them, h1, h2, H1, and H2 can be specifically set according to the specification parameters of the battery cell 100 and the design parameters of the production process. By setting the above-mentioned first preset relationship, it can be ensured that during the deformation process of the battery cell 100, the ratio of the size of the two symmetrical structures (i.e., the part between the first pressing part 201 and the clamping device, and the part between the second pressing part 202 and the clamping device) in the thickness direction (i.e., the second direction) remains constant, and the ratio is determined by the difference between the preset sizes of the starting state and the ending state of the deformation. This ensures that the deformation process of the battery cell 100 in the second direction is uniform in size, thereby effectively improving the uniformity of its internal structure and improving the molding quality of the final battery cell product.

[0151] refer to Figure 5 As shown, in some embodiments, the clamping device includes two groups of clamping components arranged along the first direction, and the clamping components include inner clamping pins 203 located radially inside the battery core 100 and outer clamping pins 204 located radially outside the battery core 100. Figure 2 As shown, the pressing device includes a first pressing part 201 and a second pressing part 202 arranged along the second direction. The clamping device continues to move along the first direction to stretch the battery cell 100, including: making the distance L between the two inner clamping needles 203 and the distance H between the first pressing part 201 and the second pressing part 202 meet the second preset relationship.

[0152] The second preset relationship may be a difference relationship, a proportional relationship, etc. The purpose of maintaining a certain second preset relationship between L and H is to keep the deformation rate of the battery cell 100 in the first direction and the second direction stable during the stretching and pressing process, so as to reduce the local stress concentration phenomenon that may be caused by uneven deformation, thereby improving the distribution uniformity of the internal structure of the battery cell 100 and improving the molding quality of the final battery cell product.

[0153] As an example, see Figure 4, from left to right, shows the process of the battery cell 100 being deformed from the first preset state to the second preset state in some embodiments of the present application. Wherein, L1 is the distance between the two inner clamping needles 203 when the battery cell 100 is in the first preset state, and H1 is the distance between the first pressing part 201 and the second pressing part 202 when the battery cell 100 is in the first preset state; L2 is the distance between the two inner clamping needles 203 when the battery cell 100 is in the second preset state, and H2 is the distance between the first pressing part 201 and the second pressing part 202 when the battery cell 100 is in the second preset state; L is the distance between the two inner clamping needles 203 in any state of the battery cell 100 in the process of deforming from the first preset state to the second preset state, and H is the distance between the first pressing part 201 and the second pressing part 202 in the corresponding state.

[0154] The above-mentioned second preset relationship includes: L / H=L2-L1 / H1-H2. By setting such a second preset relationship, the ratio of the dimensions of the battery cell 100 in the width direction (i.e., the first direction) and the thickness direction (i.e., the second direction) is actually kept constant during the deformation process, and the ratio is determined by the difference between the preset dimensions of the initial state and the final state of the deformation. This ensures that the deformation process of the battery cell 100 is uniform in size, thereby effectively improving the uniformity of its internal structure and improving the molding quality of the final battery cell product.

[0155] In addition to controlling the deformation process of the battery cell 100 by setting the proportional relationship between the stretched width and the pressed thickness of the battery cell 100 as described above, the deformation process of the battery cell 100 can also be controlled by controlling parameters such as the stretching distance and the stretching torque.

[0156] In some embodiments, the clamping device includes two groups of clamping components arranged along a first direction, so that the clamping device continues to move along the first direction to stretch the battery cell 100, including: driving the two groups of clamping components away from each other with a preset driving force F to keep the radial inner side of the battery cell 100 taut.

[0157] By setting a preset driving force F to keep the radial inner side of the battery cell 100 taut, wrinkling problems caused by redundancy can be avoided, so that the inner circle pole pieces and diaphragms can be fully stretched, so that the distance between the cathode and anode pole pieces of the battery cell 100 can also meet the process requirements, which helps to ensure the final molding quality of the battery cell 100.

[0158] Among them, the size of the preset driving force F can be adjusted according to the characteristic parameters of the battery cell 100 (such as thickness, width, material, etc.) to ensure that under this torque, the pole pieces, diaphragms and other structures of the battery cell 100 do not appear wrinkled, thereby accurately controlling the appropriate degree of stretching and ensuring the stability of the internal structure of the battery cell 100 during the stretching process.

[0159] Specifically, in some embodiments, the preset driving force F is 10-30N.

[0160] The applicant has found in practice that when the battery cell 100 is clamped and stretched by a clamping device, problems such as excessive local stress or indentations and wrinkles may occur due to local clamping, which may affect the molding quality of the battery cell 100 .

[0161] Therefore, in some embodiments, during the stretching of the battery cell 100, the clamping force of the clamping device can be adjusted in real time according to the shape of the battery cell 100, and the clamping assembly can even be loosened in time to provide a certain adjustment space for the position of the clamping assembly relative to the battery cell 100.

[0162] In the actual production process, if it is found that the clamping position of any group of clamping components has uneven shape problems such as wrinkles, cracks, etc., the outer clamping needle 204 of the clamping component can be loosened in time.

[0163] Specifically, in some embodiments, the clamping device includes two groups of clamping components arranged along the first direction, the clamping components include an inner clamping needle 203 located radially inside the battery cell 100 and an outer clamping needle 204 located radially outside the battery cell 100, and in the process of causing the clamping device to continue to move along the first direction to stretch the battery cell 100, the two outer clamping needles 204 are both in a position capable of clamping the battery cell 100 or are both in a position to release the clamping of the battery cell 100; or, one outer clamping needle 204 is in a position capable of clamping the battery cell 100, and the other outer clamping needle 204 is in a position to release the clamping of the battery cell 100.

[0164] You can refer to Figure 6 , shows that in some embodiments of the present application, during the stretching and squeezing process of the battery cell 100, the outer clamping pin 204 of the clamping assembly on the left side of the battery cell 100 is loosened (the outer clamping pin 204 of the left clamping assembly is separated from the battery cell 100), so that the clamping assembly on the left side partially releases the clamping operation of the battery cell 100. In this case, the outer clamping pin 204 on the left side is loosened, while the inner clamping pins 203 on the left and right sides continue to keep away from each other to continuously stretch the battery cell 100. Due to the continued action of the pulling force, the inner clamping pin 203 of the clamping assembly on the left side can achieve a certain sliding relative to the inner ring of the battery cell 100, thereby automatically adjusting to a position that keeps the inner ring of the battery cell 100 taut, so as to avoid wrinkles, cracks and other problems at the clamping position, so that the pole piece and diaphragm of the battery cell 100 are fully stretched.

[0165] In some embodiments, the battery cell forming method of the present application also includes: after simultaneously using a clamping device and a pressing device to stretch the battery cell 100 to a second preset state, releasing the clamping device from clamping the battery cell 100, and using a pressing device to squeeze the battery cell 100 along the second direction to a third preset state.

[0166] As an example, see Figure 1 , from left to right, shows a state schematic diagram of the process in which the battery cell 100 in some embodiments of the present application is transformed from a first preset state (the first state diagram from left to right) to a second preset state (the third state diagram from left to right), and then to a third preset state (the sixth state diagram from left to right).

[0167] In the above embodiment, the second preset state can be set as the final support state of the battery cell 100, that is, the battery cell 100 in the second preset state is already in a fully stretched state. In this case, the clamping device can be withdrawn. Specifically, Figure 1 As shown in the fourth state diagram from left to right, the inner clamping needle 203 and the outer clamping needle 204 of the clamping device are released from the battery cell 100, and the clamping assembly is withdrawn along the axial direction of the battery cell 100; Figure 1 As shown in the fifth and sixth state figures from left to right in the figure, the battery cell 100 is compacted to a third preset state along the second direction by a pressing device to complete the forming of the battery cell 100.

[0168] For the convenience of description, a specific embodiment of the battery cell forming method of the present application is described below.

[0169] In the present embodiment, a battery cell forming device 200 is provided. The battery cell forming device 200 includes a driving device, a clamping device and a pressing device. The driving device is configured to drive the clamping device and the pressing device to move.

[0170] In this embodiment, the clamping device includes two groups of clamping components arranged along the first direction, the clamping components include an inner clamping needle 203 located radially inside the battery cell 100 and an outer clamping needle 204 located radially outside the battery cell 100; the pressing device includes a first pressing part 201 and a second pressing part 202 arranged along the second direction, the first pressing part 201 is configured as a pressing plate, and the second pressing part 202 is configured as a conveyor belt, and the conveyor belt is configured to move along the first direction to transport the battery cell 100.

[0171] In this embodiment, reference can be made to Figure 1 As shown, the first direction (x direction) is the width direction of the battery cell 100 , and the second direction (y direction) is the thickness direction of the battery cell 100 .

[0172] refer to Figure 2 and Figure 5As shown, in this embodiment, the driving device includes a first driving member 205 , a second driving member 206 , a support rod 207 , a support plate 208 , a third driving member 209 , a fourth driving member 210 and a fifth driving member 211 .

[0173] Among them, the first driving member 205 is configured to drive the pressure plate (first pressing part 201) to move along the second direction; the second driving member 206 is configured to drive the clamping device to move along the second direction; the third driving member 209 is connected to the outer clamping needle 204 so that the outer clamping needle 204 and the inner clamping needle 203 cooperate to clamp the battery cell 100; the fourth driving member 210 is configured to drive the clamping assembly to move along the axial direction of the battery cell 100; the fifth driving member 211 is configured to drive the two groups of clamping assemblies to move away from or closer to each other along the first direction.

[0174] In this embodiment, the battery cell forming device 200 further includes a first mounting plate 212 and a second mounting plate 213 .

[0175] refer to Figure 5 As shown, the clamping assembly and the third driving member 209 are both mounted on the first mounting plate 212; the fourth driving member 210 and the first mounting plate 212 are both arranged on the second mounting plate 213, and the fourth driving member 210 is drivingly connected to the first mounting plate 212 to drive the first mounting plate 212 to move along the axial direction of the battery cell 100 on the second mounting plate 213; the second mounting plate 213 is mounted on the support plate 208, and the fifth driving member 211 is connected between the two second mounting plates 213 to drive the two second mounting plates 213 to move away from or close to each other, so as to drive the two groups of clamping assemblies to perform the stretching operation of the battery cell 100 in the first direction. The support rod 207 is arranged perpendicular to the conveying plane of the conveyor belt (the second pressing part 202), and the clamping device is mounted on the support plate 208, so that the support plate 208 is driven to move along the support rod 207 by the second driving member 206, and the clamping device is synchronously driven to move relative to the conveyor belt.

[0176] You can refer to Figure 1 As shown, the process of forming the battery cell 100 using the battery cell forming device 200 includes at least the following steps:

[0177] The clamping device clamps the battery cell 100 for preliminary stretching;

[0178] After the initial stretching is completed, the battery cell 100 is transferred between the first pressing part 201 and the second pressing part 202 (eg Figure 1 As shown in the first state diagram from left to right);

[0179] The first pressing part 201 presses downward (i.e., the first pressing part 201 moves toward the second pressing part 202);

[0180] During the pressing process, the clamping assembly cooperates with the first pressing part 201 to stretch the battery cell 100 at least once, and the inner ring of the battery cell 100 is in a tight state;

[0181] During the pressing and stretching process, the clamping assembly and the first pressing part 201 are raised and lowered synchronously, so that the clamping assembly is always in the middle position between the first pressing part 201 and the second pressing part 202;

[0182] During the pressing and stretching process, the outer clamping pins 204 of the clamping assembly can always clamp the battery cell 100, and can be loosened on one side or both sides, so as to cooperate with the inner ring structure of the battery cell 100 to control the deformation and tension of the pole piece and the diaphragm of the outer ring of the battery cell 100;

[0183] During each of the above-mentioned simultaneous pressing and stretching processes, the distance L between the two inner clamping needles 203, the height h of the clamping assembly relative to the second pressing part 202, and the height H between the first pressing part 201 and the second pressing part 202 always satisfy the following relationship: h / H=h1-h2 / H1-H2, L / H=L2-L1 / H1-H2.

[0184] Among them, the parameters labeled 1 (h1, H1 and L1) represent the starting state parameters of each of the above-mentioned synchronous pressing and stretching processes, and the parameters labeled 2 (h2, H2 and L2) represent the ending state parameters of each of the above-mentioned synchronous pressing and stretching processes.

[0185] The present application also provides a battery manufacturing method, including the above-mentioned battery core forming method. The positive technical effects of the battery core forming method in each of the above-mentioned embodiments are also applicable to the battery manufacturing method, which will not be described in detail here.

[0186] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar parts can be referenced to each other, and for the sake of brevity, they will not be repeated in this article.

[0187] Those skilled in the art will appreciate that, in the above method of a specific embodiment, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0188] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery core forming method, characterized in that: include: Using a clamping device to clamp the battery cell (100), and causing the clamping device to move along a first direction, so as to stretch the battery cell (100) to a first preset state; and Simultaneously using a clamping device and a pressing device to deform the battery core (100) to a second preset state; Wherein, the clamping device and the pressing device are simultaneously used to deform the battery cell (100) to a second preset state, comprising: causing the clamping device to continue to move along the first direction to stretch the battery core (100), and causing the pressing device to move along a second direction to press the battery core (100) in the second direction, the second direction being perpendicular to the first direction; The clamping device comprises two groups of clamping assemblies arranged along the first direction, the clamping assemblies comprising inner clamping needles (203) located radially inside the battery core (100) and outer clamping needles (204) located radially outside the battery core (100), and the pressing device comprises a first pressing portion (201) and a second pressing portion (202) arranged along the second direction, The step of moving the pressing device along a second direction to press the battery cell (100) in the second direction comprises: In the second direction, the second pressing portion (202) is kept stationary, so that the first pressing portion (201) and the clamping device are moved closer to the second pressing portion (202); and The distance h between the clamping device and the second pressing portion (202), and the distance H between the first pressing portion (201) and the second pressing portion (202) satisfy a first preset relationship; and / or The step of causing the clamping device to continue to move along the first direction to stretch the battery cell (100) comprises: The distance L between the two inner clamping needles (203) and the distance H between the first pressing portion (201) and the second pressing portion (202) satisfy a second preset relationship; The first preset relationship includes: h / H=(h1-h2) / (H1-H2), The second preset relationship includes: L / H=(L2-L1) / (H1-H2), Wherein, h1 is the distance between the clamping device and the second pressing part (202) when the battery cell (100) is in the first preset state, h2 is the distance between the clamping device and the second pressing part (202) when the battery cell (100) is in the second preset state, H1 is the distance between the first pressing part (201) and the second pressing part (202) when the battery cell (100) is in the first preset state, H2 is the distance between the first pressing part (201) and the second pressing part (202) when the battery cell (100) is in the second preset state, L1 is the distance between the two inner clamping needles (203) when the battery cell (100) is in the first preset state, and L2 is the distance between the two inner clamping needles (203) when the battery cell (100) is in the second preset state.

2. The battery core forming method according to claim 1, characterized in that: The pressing device comprises a first pressing portion (201) and a second pressing portion (202) arranged along the second direction, and moving the pressing device along the second direction to press the battery cell (100) in the second direction comprises: bringing the first pressing portion (201) and the second pressing portion (202) closer together along the second direction; and The first pressing portion (201) and the second pressing portion (202) are both kept at equal distances from the clamping device.

3. The battery core forming method according to claim 2, characterized in that: The step of bringing the first pressing portion (201) and the second pressing portion (202) closer together along the second direction comprises: In the second direction, the first pressing portion (201) is kept stationary, so that the second pressing portion (202) and the clamping device move closer to the first pressing portion (201); or In the second direction, the second pressing portion (202) is kept stationary, so that the first pressing portion (201) and the clamping device move closer to the second pressing portion (202); or In the second direction, the clamping device is kept stationary, so that the first pressing portion (201) and the second pressing portion (202) are moved closer to the clamping device.

4. The battery core forming method according to claim 2, characterized in that: The step of maintaining an equal distance between the first pressing portion (201) and the second pressing portion (202) and the clamping device comprises: In the second direction, the second pressing part (202) is kept stationary, the first pressing part (201) is moved toward the second pressing part (202) at a first speed, and the clamping device is moved toward the second pressing part (202) at a second speed, wherein the first speed is twice the second speed; or In the second direction, the clamping device is kept stationary, so that the first pressing part (201) and the second pressing part (202) approach the clamping device at the same speed.

5. The battery core forming method according to claim 1, characterized in that: The clamping device comprises two groups of clamping assemblies arranged along the first direction, and causing the clamping device to continue to move along the first direction to stretch the battery cell (100) comprises: driving the two groups of clamping assemblies away from each other with a preset driving force F, so that the radial inner side of the battery cell (100) remains taut.

6. The battery core forming method according to claim 5, characterized in that: The preset driving force F is 10-30N.

7. The battery core forming method according to claim 1, characterized in that: The clamping device comprises two groups of clamping assemblies arranged along the first direction, the clamping assemblies comprising inner clamping needles (203) located radially inside the battery core (100) and outer clamping needles (204) located radially outside the battery core (100), and in the process of causing the clamping device to continue to move along the first direction to stretch the battery core (100), The two outer clamping needles (204) are both located at positions capable of clamping the battery core (100) or are both located at positions for releasing the clamping of the battery core (100); or One of the outer clamping needles (204) is located at a position capable of clamping the battery core (100), and the other outer clamping needle (204) is located at a position for releasing the clamping of the battery core (100).

8. The battery core forming method according to claim 1, characterized in that: Also includes: After the battery cell (100) is stretched to a second preset state by using the clamping device and the pressing device simultaneously, the clamping device on the battery cell (100) is released, and the pressing device is used to press the battery cell (100) along the second direction to a third preset state.

9. A battery manufacturing method, characterized in that: The invention comprises a battery core forming method as claimed in any one of claims 1 to 8.

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