Production method of wound battery

Abstract

The present disclosure relates to the technical field of battery production, and in particular to a method for producing a wound battery, the production method comprising: preparing a cylindrical battery cell, the cylindrical battery cell comprising a wound positive electrode sheet, a wound negative electrode sheet and a separator; shaping the battery cell, and deforming the battery cell into a non-cylindrical shape, thereby preparing a non-cylindrical wound battery. The present disclosure provides a method for producing a wound battery, first making the battery cell into a cylindrical battery cell, and then making the cylindrical battery cell into a set non-cylindrical battery, for example, making it into a rectangular battery. With this production method, the cylindrical battery cell adopts a circular ring winding method. The battery cell structure prepared in this way has uniform winding stress, high interface consistency, uniform battery current density, and excellent performance, and can improve the production efficiency of the winding process. At the same time, the preparation of cylindrical battery cells can reduce equipment configuration, facilitate repair and maintenance, and save production costs and space.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery production, and in particular to a method for producing a wound battery. Background Art

[0002] There are two main matching solutions for existing square batteries and positive and negative electrodes. One is to wind the positive and negative electrodes into a square shape. The winding core is similar in shape to the square shell, and the core package can be placed directly into the square shell individually or in a core group. The other is to stack the positive and negative electrodes, that is, cut the positive and negative electrodes into a shape similar to the square shell, and stack them together to form a core package, which is then placed directly into the square shell.

[0003] However, the existing matching schemes all have defects. Among them, in the first scheme, in order to ensure that the positive and negative electrode sheets do not shake when they are wound in a square shape, a winding scheme with changing angular velocity and constant linear speed is adopted, thereby reducing production efficiency. At the same time, there are corners in the square winding and the interface uniformity is poor. In the second scheme, when the positive and negative electrode sheets are stacked, the electrode sheets need to have a stroke to be taken and placed, and there is a sequence of placement, which reduces production efficiency. Summary of the invention

[0004] In order to solve at least the above technical problems existing in the prior art, an embodiment of the present invention provides a method for producing a wound battery.

[0005] One aspect of an embodiment of the present disclosure provides a method for producing a wound battery, which is used for producing a non-cylindrical wound battery, the method comprising: preparing a cylindrical battery cell, the cylindrical battery cell comprising a wound positive electrode sheet, a wound negative electrode sheet and a separator; shaping the battery cell to transform the battery cell into a non-cylindrical shape, thereby preparing the non-cylindrical wound battery.

[0006] In some embodiments, the method for preparing a cylindrical battery cell includes: winding to prepare a cylindrical core; placing the core in a cylindrical shell to prepare the cylindrical battery cell.

[0007] In some embodiments, the method for preparing a cylindrical winding core by winding includes: winding the positive electrode sheet, the negative electrode sheet and the separator into the cylindrical winding core by a winding machine.

[0008] In some embodiments, the method for winding a cylindrical core also includes: adjusting the spacing between the positive electrode sheet, the negative electrode sheet and the separator by adjusting the rotation speed and / or tension of the winding needle in the winding machine so that the winding stress of the cylindrical core is uniform.

[0009] In some embodiments, the method of placing the core in a cylindrical shell to prepare the cylindrical battery cell includes: the shell includes a accommodating cavity, the core is placed in the accommodating cavity, and the axis of the core coincides with the axis of the accommodating cavity, and the height of the shell along the axial direction is not less than the height of the core.

[0010] In some embodiments, the method of shaping the battery cell to transform the battery cell into a non-cylindrical shape includes: applying pressure to the outer wall of the shell to cause the winding core and the shell to deform synchronously, thereby transforming the battery cell into a set non-cylindrical shape.

[0011] In some embodiments, the method of shaping the battery cell to transform the battery cell into a non-cylindrical shape further includes: performing one or more steps of extrusion deformation on the battery cell through an extrusion die.

[0012] In some embodiments, the battery core includes a shaping area; buffer spacing is respectively provided in the shaping area, between adjacent stacked structures in the winding core, and between the outer wall of the winding core and the inner wall of the shell.

[0013] In some embodiments, the cross-sectional shape of the cylindrical battery cell is circular or elliptical.

[0014] The present disclosure provides a method for producing a wound battery, which first manufactures the battery cell into a cylindrical cell, and then manufactures the cylindrical cell into a predetermined non-cylindrical battery, for example, a rectangular battery. With this production method, the cylindrical cell is wound in a circular ring shape. The cell structure prepared in this way has uniform winding stress, high interface consistency, uniform battery current density, and excellent performance, and can improve the production efficiency of the winding process. At the same time, the preparation of cylindrical cells can reduce equipment configuration, facilitate maintenance and repair, and save production costs and space. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0016] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0017] Figure 1 It is a schematic diagram of an optional process flow of the method for producing a wound battery provided in an embodiment of the present disclosure;

[0018] Figure 2 It is a schematic diagram of an optional process flow of the method for producing a wound battery provided in an embodiment of the present disclosure;

[0019] Figure 3 is a schematic diagram of the structure of the winding core in the method for producing a wound battery provided by an embodiment of the present disclosure;

[0020] Figure 4 is a schematic diagram of the structure of a battery cell in a method for producing a wound battery provided in an embodiment of the present disclosure;

[0021] Figure 5 It is a schematic structural diagram of a non-cylindrical wound battery in the method for producing a wound battery provided in an embodiment of the present disclosure.

[0022] In the figure:

[0023] 1: winding core; 2: shell; 3: cylindrical battery cell; 4: non-cylindrical battery cell. DETAILED DESCRIPTION

[0024] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0025] Figure 1 FIG. 1 is a schematic diagram of an optional process flow of the method for producing a wound battery provided in an embodiment of the present disclosure. Figure 1 As shown, a method for producing a wound battery is used for producing a non-cylindrical wound battery, the method comprising:

[0026] Step S10: preparing a cylindrical battery cell, wherein the cylindrical battery cell comprises a wound positive electrode sheet, a wound negative electrode sheet and a separator.

[0027] In the embodiment of the present disclosure, when preparing the battery cell, a toroidal winding method is used to prepare a cylindrical battery cell. Based on this, the toroidal winding method makes the stress of the battery cell uniform, the interface consistency is high, and the battery current density is uniform, and the performance is excellent; in addition, the toroidal winding method can also improve the production efficiency of the winding process.

[0028] For example, the original square wound battery cell production line has a production capacity of about 10 to 12 cells per minute, while the circular wound battery cell production line has a production capacity of about 150 to 200 cells per minute.

[0029] For example, the cross-sectional shape of a cylindrical battery cell is circular or elliptical.

[0030] Step S20: shaping the battery cell to transform the battery cell into a non-cylindrical shape, thereby preparing a non-cylindrical wound battery.

[0031] In the embodiment of the present disclosure, in step S10, the battery cell is produced in a cylindrical shape, and then the cylindrical battery cell is shaped, for example, by extruding the battery cell to deform it into a desired shape. For example, the battery cell is extruded and deformed into a rectangular parallelepiped. In the embodiment of the present disclosure, the desired shape is not limited.

[0032] In some embodiments, pressure is applied to the outer wall of the shell to cause the core and the shell to deform synchronously, thereby causing the battery cell to deform into a set non-cylindrical shape. The shell and the core will deform under the action of external force. For example, the thickness of the outer wall of the shell can meet the deformation requirements while meeting the function of the shell.

[0033] For example, the battery cell is subjected to one or more steps of extrusion deformation by an extrusion die. For example, the extrusion die includes an upper pressing plate and a lower pressing plate, the inner frame shape of the die is consistent with the size and shape of the battery cell to be formed, the cylindrical battery cell is placed in the inner frame, and the cylindrical battery cell in the inner frame is extruded by the upper pressing plate and the lower pressing plate, thereby deforming into the contour shape of the inner frame.

[0034] Figure 2 FIG. 1 is a schematic diagram of an optional process flow of the method for producing a wound battery provided in an embodiment of the present disclosure. Figure 2 As shown, in the method for producing a wound battery, step S10 includes:

[0035] Step S11: Winding to prepare a cylindrical winding core. The winding core structure includes a positive electrode sheet, a negative electrode sheet and a separator. According to the design requirements of the winding core, the positive electrode sheet, the negative electrode sheet and the separator are stacked and wound in a set stacking manner.

[0036] For example, the positive electrode sheet, the negative electrode sheet and the separator are wound into a cylindrical winding core by a winding machine. The winding needle of the winding machine is a ring-shaped winding needle, and the positive electrode sheet, the negative electrode sheet and the separator are wound together by the rotation of the ring-shaped winding needle to finally form a cylindrical winding core.

[0037] In some embodiments, by using a winding machine to prepare a cylindrical winding core, the number of production equipment used can be reduced, that is, there is no need to perform operations such as angular velocity changes, and there is no need to perform stacking operations. Therefore, related equipment is correspondingly omitted to achieve the purpose of structural optimization.

[0038] For example, the spacing between the positive electrode sheet, the negative electrode sheet and the separator is adjusted by adjusting the rotation speed and / or tension of the winding needle in the winding machine so that the winding stress of the cylindrical winding core is uniform.

[0039] For example, buffer spacing is provided between adjacent superimposed structures in the winding core and between the outer wall of the winding core and the inner wall of the shell in the shaping area. In the winding core, the outer part of the entire winding core is the main deformation area, and the spacing of the deformation area can be adjusted by adjusting the rotation speed and / or tension of the winding needle, that is, adding a buffer spacing to avoid insufficient deformation space when the battery cell is deformed.

[0040] For example, when the core is wound to a first thickness, the spacing between the positive electrode sheet, the negative electrode sheet and the separator in the core is a first spacing. After the core is wound to the first thickness, the spacing between the positive electrode sheet, the negative electrode sheet and the separator in the core is a second spacing, wherein the second spacing is greater than the first spacing; or, after the core is wound to the first thickness, the spacing between the positive electrode sheet, the negative electrode sheet and the separator in the core gradually increases.

[0041] Step S12: placing the winding core in a cylindrical shell to prepare a cylindrical battery cell.

[0042] For example, the shell includes a containing cavity, the winding core is placed in the containing cavity, the axis of the winding core coincides with the axis of the containing cavity, and the height of the shell along the axial direction is not less than the height of the winding core.

[0043] For example, the shell is a sleeve structure, the interior of the sleeve structure is a receiving cavity, the height of the sleeve structure is the same as the height of the core, and the two ends of the sleeve are sealed to form a cylindrical battery core. When the core is placed in the shell, the outer wall of the core fits the inner wall of the shell, or a part of the deformation space is reserved.

[0044] Step S20: shaping the battery cell to transform the battery cell into a non-cylindrical shape, thereby preparing a non-cylindrical wound battery.

[0045] Figure 3 Schematic diagram of the structure of the winding core in the method for producing a wound battery provided by an embodiment of the present disclosure. Figure 3 As shown, in step S11 of the method for producing a wound battery provided in an embodiment of the present disclosure, the positive electrode sheet, the negative electrode sheet and the separator are wound into a cylindrical winding core 1 by a winding machine.

[0046] Figure 4 Schematic diagram of the structure of the battery cell in the method for producing a wound battery provided by an embodiment of the present disclosure. Figure 4 As shown, in step S12 of the method for producing a wound battery according to an embodiment of the present disclosure, the winding core 1 is placed in a cylindrical shell 2 to prepare a cylindrical battery cell 3. The shell 2 can be prepared by stamping or welding, etc. In the embodiment of the present disclosure, the manufacturing process of the shell 2 is not limited. After the winding core 1 is placed in the shell 2, a sealing operation is required. In the embodiment of the present disclosure, the sealing operation form is not limited.

[0047] Figure 5 Schematic diagram of the structure of a non-cylindrical wound battery in the method for producing a wound battery provided by an embodiment of the present disclosure. Figure 5 As shown, in step S20 of the method for producing a wound battery provided in an embodiment of the present disclosure, the cylindrical battery cell 3 is shaped to obtain a non-cylindrical battery cell 4.

[0048] The method for producing a wound battery provided by the embodiment of the present disclosure has at least the following advantages:

[0049] 1. Improve equipment efficiency and reduce investment costs;

[0050] 2. Improved equipment efficiency leads to lower fuel costs, direct labor, and manufacturing costs;

[0051] 3. The winding mechanism is simplified and the maintenance time is reduced;

[0052] 4. The battery layer spacing is consistent, the battery interface is good, the current density is evenly distributed, the battery consistency is improved, and the safety hazard of lithium short circuit and fire caused by the layer spacing at the corners of the square battery cell is prevented.

[0053] The disclosed embodiments also provide a wound battery production device, which includes a production line, and the production line includes at least a winding position, an assembly position, and a molding position. The winding position includes a winding machine, and a cylindrical core winding operation is performed by using the winding machine; the core and the shell are assembled and prepared into a battery cell at the assembly position. For example, at the assembly position, automated equipment such as a manipulator can be used to operate the battery cell; at the molding position, an extrusion module is used to perform extrusion molding operations. The production equipment is an automated equipment, and the raw materials are fed in from one side of the production line, and finally the molded wound battery is output.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are contradictory.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for producing a wound battery, for producing a non-cylindrical wound battery, characterized in that: The method comprises: Prepare a cylindrical battery cell, wherein the cylindrical battery cell comprises a wound positive electrode sheet, a negative electrode sheet and a separator; Shaping the battery cell to transform the battery cell into a non-cylindrical shape, thereby preparing the non-cylindrical wound battery; The method for preparing a cylindrical battery core comprises: winding to prepare a cylindrical winding core; placing the winding core in a cylindrical shell to prepare the cylindrical battery core; the cross-sectional shape of the cylindrical battery core is circular or elliptical.

2. The method for producing a wound battery according to claim 1, characterized in that: The method for preparing a cylindrical winding core by winding comprises: The positive electrode sheet, the negative electrode sheet and the separator are wound into the cylindrical winding core by a winding machine.

3. The method for producing a wound battery according to claim 2, characterized in that: The method for preparing a cylindrical winding core by winding also includes: The spacing between the positive electrode sheet, the negative electrode sheet and the separator is adjusted by adjusting the rotation speed and / or tension of the winding needle in the winding machine so that the winding stress of the cylindrical winding core is uniform.

4. The method for producing a wound battery according to claim 1, characterized in that: The method of placing the winding core in a cylindrical shell to prepare the cylindrical battery core includes: The housing comprises a receiving cavity, the winding core is placed in the receiving cavity, and the axis of the winding core coincides with the axis of the receiving cavity, and The height of the shell along the axial direction is not less than the height of the winding core.

5. The method for producing a wound battery according to claim 4, characterized in that: The method for shaping the battery core to transform the battery core into a non-cylindrical shape comprises: Pressure is applied to the outer wall of the shell to cause the winding core and the shell to deform synchronously, thereby causing the battery core to deform into a set non-cylindrical shape.

6. The method for producing a wound battery according to claim 4, characterized in that: The method for shaping the battery core to transform the battery core into a non-cylindrical shape also includes: The battery core is subjected to one or more steps of extrusion deformation by an extrusion die.

7. The method for producing a wound battery according to claim 1, characterized in that: The battery cell includes a shaping area; Buffering spacings are respectively provided in the shaping area, between adjacent superimposed structures in the winding core, and between the outer wall of the winding core and the inner wall of the shell.

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