CN112510245B

CN112510245B - Battery cell manufacturing device and method

Info

Publication number: CN112510245B
Application number: CN202110121974.5A
Authority: CN
Inventors: 阳超; 张小畏; 唐鸣浩; 林文法
Original assignee: Jiangsu Contemporary Amperex Technology Ltd
Current assignee: Jiangsu Contemporary Amperex Technology Ltd
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-05-18
Anticipated expiration: 2041-01-29
Also published as: CN112510245A

Abstract

The application relates to a battery cell manufacturing device and a battery cell manufacturing method. The electric core comprises a first pole piece, a second pole piece and a diaphragm, the electric core is provided with a winding starting ring positioned on the inner side, and the electric core manufacturing device comprises: the winding needle is configured to wind the first pole piece, the second pole piece and the diaphragm to form an electric core, and a winding starting ring is wound on the periphery of the winding needle in the initial winding stage of the winding needle; a heating assembly configured to heat a predetermined position of the winding start coil to thermally compound at least one of the first and second pole pieces at the predetermined position with the separator. The application provides a battery core manufacturing device, aims at solving the problem that lithium is separated out in the inner ring part of a battery core.

Description

Battery cell manufacturing device and method

Technical Field

The present application relates to the field of battery technologies, and in particular, to a battery cell manufacturing apparatus and a battery cell manufacturing method.

Background

In the production process of the battery, the pole piece and the diaphragm need to be wound into a battery core by using winding equipment. The electric core after coiling and prepressing shaping is in a flat structure. However, in the use process of the battery cell after winding and pre-pressing for shaping, the lithium precipitation condition exists at the inner ring part, which affects the use safety of the battery cell.

Disclosure of Invention

The application provides a battery cell manufacturing device and a method thereof, aiming at solving the problem that lithium is separated out at the inner ring part of a battery cell.

In one aspect, the application provides a device is made to electric core, and electric core includes first pole piece, second pole piece and diaphragm, and electric core has the initial circle of coiling that is located the inboard, and device is made to electric core includes:

the winding needle is configured to wind the first pole piece, the second pole piece and the diaphragm to form an electric core, and a winding starting ring is wound on the periphery of the winding needle in the initial winding stage of the winding needle; a heating assembly configured to heat a predetermined position of the winding start coil to thermally compound at least one of the first and second pole pieces at the predetermined position with the separator.

According to the battery cell manufacturing device provided by the embodiment of the application, the first pole piece, the second pole piece and the diaphragm are wound by the winding needle to form the battery cell. The predetermined position of the winding start coil may be heated using a heating assembly to thermally compound at least one of the first and second pole pieces with the diaphragm in the predetermined position such that the diaphragm is no longer free but is constrained by the first and/or second pole pieces. After the battery core after being wound is stretched to be flat, the diaphragm positioned at the inner ring part is restrained, so that tensile stress is not easy to accumulate in the diaphragm and the diaphragm is not easy to retract, the possibility that the first pole piece and the second pole piece of the inner ring part are too large in gap due to the fact that the diaphragm retracts to drive the first pole piece and the second pole piece to move inwards is reduced, and the possibility of lithium precipitation is reduced.

According to one embodiment of the application, the heating assembly comprises a heater and a pressing piece, the heater is configured to heat the preset position, the pressing piece is arranged on the outer side of the winding needle, and the pressing piece is configured to apply pressure to the preset position.

The heater of the heating assembly can heat the preset position of the winding starting ring to a preset temperature so as to melt the corresponding area of the diaphragm and enable the melting degree to reach a preset state. The pressing member applies a predetermined pressure to the completely heated separator from the outside of the winding start coil. Under the co-extrusion action of the pressing piece and the winding needle, the diaphragm and at least one of the first pole piece and the second pole piece can be thermally compounded with the diaphragm.

According to an embodiment of the application, the heating assembly further comprises a driving part, the pressing part is connected with the driving part, and the driving part is configured to drive the pressing part to be close to or far away from the winding needle.

The driving part can improve the accuracy of the pressure applied by the pressing part to the winding starting ring, is beneficial to reducing the error between the pressure applied to the winding starting ring and a preset pressure value, and reduces the possibility that at least one of the first pole piece and the second pole piece is separated again after being thermally compounded with the diaphragm or at least one of the first pole piece, the second pole piece and the diaphragm is structurally damaged.

According to an embodiment of the application, the driving part comprises a mounting seat and a telescopic piece, the telescopic piece is configured to drive the mounting seat to be close to or far away from the winding needle, and the pressing piece is arranged on the mounting seat.

The telescopic piece can play a better restraint effect to the pressing piece at the side of the pressing piece far away from the winding needle, and the pressure applied to the winding start ring due to the fact that the pressing piece moves towards the direction far away from the winding needle is reduced.

According to one embodiment of the application, the heater is arranged on the pressing piece, and the heater heats the preset position through the pressing piece.

The heater is arranged on the pressing piece, so that the heater can heat the pressing piece in real time, the temperature of the pressing piece is always kept at the preset temperature, and the possibility of thermal recombination failure or poor effect caused by large fluctuation of the temperature of the pressing piece is reduced.

According to an embodiment of the application, the heating assembly further comprises a first temperature sensor configured to monitor a temperature of the pressing member.

The temperature of the pressing piece can be monitored in real time through the first temperature sensor, whether the temperature of the pressing piece is at the preset temperature or not can be conveniently judged, and the possibility that the thermal compound effect is poor due to the fact that the temperature of the pressing piece is higher or lower is favorably reduced.

According to one embodiment of the application, the pressing member is a hollow structure, and at least part of the heater is accommodated in the pressing member.

The heater is arranged in the pressing piece, so that the heater can easily keep the heating state of each region of the pressing piece consistent, the temperature rise of each region of the pressing piece is kept consistent, the possibility that the heating effect of the battery cell diaphragm is different due to the fact that the temperature of the region where the pressing piece is contacted with the battery cell is uneven is favorably reduced, and the possibility that at least one of the first pole piece and the second pole piece is adhered to the diaphragm in the heating region to different degrees is further reduced.

According to one embodiment of the present application, the heater is disposed inside the winding needle and configured to heat a region on the winding needle opposite to the predetermined position.

Because the heater is arranged in the winding needle, the winding needle can continuously rotate, and the end part of the winding starting ring, different areas of the winding starting ring or the whole winding starting ring is thermally compounded in the rotating process, so that the winding working efficiency is effectively improved.

According to an embodiment of the application, the heating assembly further comprises a second temperature sensor, the second temperature sensor is arranged on the winding needle, and the second temperature sensor is configured to monitor the temperature of the area, opposite to the preset position, on the winding needle.

The temperature of the area, opposite to the preset position of the winding starting ring, on the winding needle can be monitored in real time through the second temperature sensor, whether the temperature of the area, opposite to the preset position of the winding starting ring, on the winding needle is at the preset temperature or not is judged conveniently, and the possibility that the thermal compound effect is poor due to the fact that the local temperature of the winding needle is higher or lower is reduced.

According to an embodiment of the application, the periphery of book needle has the groove of stepping down that is used for electric core unloading, along the circumference of book needle, at least one side sets up the heater in the both sides in the groove of stepping down.

The heater heats the winding starting ring and two thermal compound areas formed by the pressing of the pressing piece are positioned in the bending area or close to the bending area, so that the possibility that the diaphragm in the bending area drives the first pole piece or the second pole piece to move inwards is favorably reduced.

According to one embodiment of the application, the heating assembly further comprises an anti-adhesive member, at least part of the outer surface of the pressing member covering the anti-adhesive member, the pressing member applying pressure to the predetermined location through the anti-adhesive member.

Because the anti-sticking component arranged on the pressing piece has the anti-sticking function, the heating assembly is not easy to stick to the winding starting ring, and the possibility of drawing the winding starting ring when the heating assembly is pulled due to the sticking of the heating assembly and the winding starting ring is reduced.

According to one embodiment of the application, the pressing member is a press roller.

The pressing piece can rotate along with the rotation of the winding needle, so that the heating assembly can continuously perform thermal compounding on the winding starting ring, the winding needle does not need to stop rotating, the thermal compounding consistency and stability of the winding starting ring are favorably improved, and the thermal compounding work efficiency is also improved.

According to one embodiment of the application, the pressing piece is a pressing piece matched with the shape of the winding needle.

When the pressing piece applies pressure to the winding starting ring, the winding needle is kept static, so that relative displacement does not exist between the winding needle and the pressing piece, and the possibility that at least one of the first pole piece, the second pole piece and the diaphragm is wrinkled due to relative movement of the pressing piece and the winding starting ring can be reduced.

In another aspect, a method for manufacturing a battery cell is provided according to the present application, which includes:

winding a first pole piece, a diaphragm and a second pole piece of the battery cell to form a winding starting ring;

and heating the preset position of the winding starting ring to thermally compound at least one of the first pole piece and the second pole piece at the preset position with the diaphragm.

The cell manufacturing method of the embodiment of the application is used for manufacturing the cell of the embodiment. In the method for manufacturing the battery cell of the embodiment of the application, the first pole piece, the second pole piece and the diaphragm are wound to form the battery cell. And heating the preset position of the winding starting ring to ensure that at least one of the first pole piece and the second pole piece is in thermal compound connection with the diaphragm at the preset position, so that the diaphragm is not in a free state any more, but is restrained by the first pole piece and the second pole piece. Because the diaphragm positioned at the inner ring part is restrained, the diaphragm at the inner ring part is not easy to retract, so that the possibility that the first pole piece and the second pole piece of the inner ring part have overlarge gaps with each other due to the fact that the diaphragm retracts to drive the first pole piece and the second pole piece to move inwards is reduced, and the possibility of lithium precipitation is further reduced.

According to an embodiment of the present application, the heating time is 2 to 5 seconds when the predetermined position of the winding start coil is heated.

When the heating time is less than 2 seconds, there is a possibility that the heating time is short and the degree of melting of the separator does not meet a predetermined requirement, thereby causing poor thermal recombination effect or thermal recombination failure. If the heating time is longer than 5 seconds, the heating time may be long, and the degree of melting of the separator may exceed a predetermined level, thereby causing breakage of the separator and failure of the separator.

According to one embodiment of the present application, the heating temperature is 85 to 95 degrees when the predetermined position of the winding start coil is heated.

When the heating temperature is lower than 85 degrees, there is a possibility that the heating temperature is low and the degree of melting of the separator does not meet a predetermined requirement, thereby causing poor thermal recombination effect or thermal recombination failure. When the heating temperature is higher than 95 degrees, the heating temperature is high, and the degree of melting of the separator exceeds a predetermined level, and the separator may be broken and fail.

According to one embodiment of the present application, when the predetermined position of the winding start coil is heated, pressure is applied to the predetermined position.

The first pole piece and/or the second pole piece can be adhered to the fused part of the diaphragm under the action of pressure, so that at least one of the first pole piece and the second pole piece can be successfully subjected to thermal compounding with the diaphragm, and the stable and reliable connection state is ensured.

According to one embodiment of the present application, the pressure is equal to or greater than 3 mpa and equal to or less than 10 mpa.

When the compressive stress applied to the winding start ring heating area is less than 3 MPa, the extrusion force applied to at least one of the first pole piece and the second pole piece and the diaphragm does not meet the preset pressure requirement, so that the adhesion firmness of the at least one of the first pole piece and the second pole piece and the molten part of the diaphragm does not meet the preset requirement, and further the possibility that the at least one of the first pole piece and the second pole piece and the diaphragm are separated again after thermal compounding is completed exists. When the compressive stress applied to the winding start coil heating area is greater than 10 mpa, the applied extrusion force exceeds the predetermined pressure requirement, so that at least one of the first pole piece, the second pole piece and the diaphragm is subjected to an excessive force, and the structural damage may occur.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present application will be described below by referring to the accompanying drawings.

Fig. 1 is a schematic view of a cell manufacturing apparatus according to an embodiment of the present application winding a first pole piece, a second pole piece, and a diaphragm;

FIG. 2 is a schematic view of a winding needle of an embodiment of the present application completing winding;

fig. 3 is a schematic diagram of a tensile cell of a blanking assembly according to an embodiment of the present application;

fig. 4 is a schematic view of a cell manufacturing apparatus according to another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 5 is a schematic view of a cell manufacturing apparatus according to another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 6 is a schematic view of a cell manufacturing apparatus according to another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 7 is a schematic view of a cell manufacturing apparatus according to another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

FIG. 8 is a schematic illustration in partial cross-sectional view of a heating assembly in accordance with an embodiment of the present application;

fig. 9 is a schematic view of a cell manufacturing apparatus according to another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 10 is a schematic view of a cell manufacturing apparatus according to yet another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 11 is a schematic view of a cell manufacturing apparatus according to still another embodiment of the present application winding a first pole piece, a second pole piece, and a separator;

fig. 12 is a schematic flow chart of a cell manufacturing method according to an embodiment of the present application.

In the drawings, the drawings are not necessarily drawn to scale.

Description of the labeling:

10. an electric core; 10a, winding a starting ring; 10b, a bending area; 11. a first pole piece; 12. a second pole piece; 13. a diaphragm;

20. coiling a needle; 20a, a yielding groove; 21. a first half shaft; 22. a second half shaft;

30. a heating assembly; 31. a heater; 32. a pressing member; 33. a drive member; 331. a mounting seat; 332. a telescoping member; 34. a first temperature sensor; 35. a second temperature sensor; 36. an anti-sticking member;

40. a blanking assembly; 41. clamping the needle at the inner side; 42. clamping the needle at the outer side;

50. a conductive slip ring;

x, horizontal direction.

Detailed Description

Embodiments of the present application will be described in further detail below with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the described embodiments.

In the description of the present application, it is to be noted that, unless otherwise specified, "a plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like, indicate an orientation or positional relationship that is merely for convenience in describing the application and to simplify the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. "vertical" is not strictly vertical, but is within the tolerance of the error. "parallel" is not strictly parallel but within the tolerance of the error.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

The following description is given with the directional terms as they are used in the drawings and not intended to limit the specific structure of the present application. In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood as appropriate by one of ordinary skill in the art.

The applicant notices that the lithium analysis problem exists in the inner ring part of the battery cell which is completely wound and subjected to the pre-pressing and shaping process in the using process. The applicant carries out research and analysis on the structure and the processing process of the battery core. The applicant found that the clearance between the positive electrode tab and the negative electrode tab at the inner ring part of the cell was too large, resulting in a problem of lithium deposition. After further research and analysis, the applicant finds that after the battery core is wound, the battery core needs to be clamped by the blanking assembly and taken down from the winding needle, then the taken-down battery core is stretched to be flat by the blanking assembly, then the blanking assembly is moved away, and prepressing and sizing are carried out on the battery core. After the battery cell which is taken down is stretched to be flat by the blanking assembly, the diaphragm which is positioned at the inner ring part is stretched to be in a tensioning state. After the blanking assembly is moved away, the diaphragm positioned at the inner ring part is in a free state, so that the diaphragm in a tensioning state can retract, the positive plate or the negative plate is driven to move inwards, and the gap between the positive plate and the negative plate at the inner ring part is overlarge.

Based on the above problems discovered by the applicant, the applicant improves the structure of the cell manufacturing apparatus, and the following further describes the embodiments of the present application.

For a better understanding of the present application, embodiments of the present application are described below with reference to fig. 1 to 11.

Referring to fig. 1 and 2, a battery cell manufacturing apparatus according to an embodiment of the present application includes a winding pin 20. The winding needle 20 is configured to wind the first pole piece 11, the second pole piece 12, and the separator 13. The first pole piece 11 and the second pole piece 12 have opposite polarities, one of them is a positive pole piece, and the other is a negative pole piece. The separator 13 is an insulator between the first pole piece 11 and the second pole piece 12. The first pole piece 11, the second pole piece 12 and the diaphragm 13 are wound on the winding needle 20 to form the battery cell 10.

The battery cell 10 has a winding start circle 10a on the inner side. In the initial stage of winding the winding needle 20, the winding start winding 10a is wound around the outer periphery of the winding needle 20. Illustratively, the first pole piece 11, the second pole piece 12, and the separator 13 are wound by the winding needle 20 together into the winding needle 20. The first pole piece 11, the second pole piece 12 and the diaphragm 13 form a winding start circle 10a at a portion where the first circle is wound on the winding needle 20. Alternatively, the winding needle 20 winds the separator 13N times in advance, and then the first pole piece 11 and the second pole piece 12 enter the winding needle 20 and are wound by the winding needle 20, at this time, when the first pole piece 11 and the second pole piece 12 are wound on the winding needle 20 for the first turn, the first pole piece 11, the second pole piece 12 and the separator 13 form a winding start turn 10 a. In one example, the value range of N is: n is more than or equal to 1 and less than or equal to 5.

The battery cell manufacturing apparatus of the embodiment of the present application further includes a heating assembly 30. The heating assembly 30 is configured to heat a predetermined position of the winding start coil 10a to thermally compound at least one of the first and

second pole pieces

11 and 12 and the separator 13 at the predetermined position, so that at least one of the first and

second pole pieces

11 and 12 and the separator 13 are connected at a thermal compound region.

In the cell manufacturing apparatus according to the embodiment of the present application, the first pole piece 11, the second pole piece 12, and the diaphragm 13 are wound by the winding needle 20 to form the cell 10. The heating assembly 30 is used to heat a predetermined position of the winding start coil 10a to thermally compound at least one of the first and

second pole pieces

11, 12 with the diaphragm 13 at the predetermined position, so that the diaphragm 13 is no longer in a free state, but is constrained by the first and/or

second pole pieces

11, 12. After the battery cell 10 after being wound is stretched to be flat, because the diaphragm 13 located at the inner ring part is restrained, the diaphragm 13 itself is not easy to accumulate tensile stress and not easy to retract, so that the possibility that the first pole piece 11 and the second pole piece 12 of the inner ring part move inwards due to the retraction of the diaphragm 13, and the gap between the first pole piece 11 and the second pole piece 12 of the inner ring part is too large is reduced, and the possibility of lithium precipitation is further reduced.

In some embodiments, the heating assembly 30 heats a predetermined position of the winding start coil 10a, so that the heated region of the separator 13 may be melted to have viscosity, and thus at least one of the first pole piece 11 and the second pole piece 12 may be adhered to the separator 13 to achieve connection. Illustratively, the material of the diaphragm 13 includes at least one of polyethylene and polypropylene.

In some embodiments, referring to fig. 1, the heating assembly 30 heats the end of the winding start coil 10a to thermally compound at least one of the first and

second pole pieces

11 and 12 of the end of the winding start coil 10a with the separator 13. In the completely wound battery cell 10, the end of the winding start coil 10a is no longer in a free state, so that collapse and deformation are less likely to occur, and the possibility of the gap between the first pole piece 11 and the second pole piece 12 becoming large is reduced.

In some embodiments, the heating assembly 30 includes a heater 31 and a pressing member 32. The heater 31 is configured to heat a predetermined position of the winding start coil 10 a. The pressing member 32 is disposed outside the winding needle 20. The pressing member 32 is configured to apply pressure to a predetermined position. The heater 31 of the heating assembly 30 may heat a predetermined position of the winding start coil 10a to a predetermined temperature to melt a corresponding region of the separator 13 and to bring the degree of melting to a preset state. The pressing member 32 applies a predetermined pressure to the completely heated separator 13 from the outside of the winding start coil 10 a. The diaphragm 13 and at least one of the first pole piece 11 and the second pole piece 12 can be thermally compounded with the diaphragm 13 under the co-pressing action of the pressing member 32 and the winding needle 20. Illustratively, the heater 31 and the pressing member 32 are each provided independently. The heater 31 is located upstream of the pressing member 32, so that the first pole piece 11, the second pole piece 12 and the diaphragm 13 pass through the heater 31 and then the pressing member 32. Upstream means that the process is advanced in the machining process.

In some embodiments, referring to fig. 2, the battery cell manufacturing apparatus of the embodiment of the present application further includes a blanking assembly 40. The blanking assembly 40 is configured to remove the battery cell 10 from the winding needle 20. The blanking assembly 40 includes an inner clamp pin 41 and an outer clamp pin 42. The inside clamp pin 41 and the outside clamp pin 42 are configured to collectively clamp the completely wound battery cell 10.

In some embodiments, the winding pin 20 includes a first half-shaft 21 and a second half-shaft 22. The first half shaft 21 and the second half shaft 22 may move closer to or away from each other. The first half shaft 21 and the second half shaft 22 are provided with a relief groove 20 a. After the winding is completed, the inner clamping pins 41 of the blanking assembly 40 may be inserted into the two relief grooves 20a of the winding pin 20, respectively. After the inner clamping pin 41 and the outer clamping pin 42 clamp the battery cell 10, the first half shaft 21 and the second half shaft 22 move closer to each other, so that the winding pin 20 is separated from the battery cell 10, and the blanking assembly 40 is convenient to remove the battery cell 10 from the winding pin 20.

In some embodiments, referring to fig. 3, the number of blanking assemblies 40 can be two. The two blanking assemblies 40 are arranged at intervals along the horizontal direction X. The two blanking assemblies 40 each hold the battery cell 10 at different positions. In the horizontal direction X, the two blanking assemblies 40 are moved away from each other, thereby stretching the battery cell 10 into a flat shape. The areas of the battery cell 10 corresponding to the two blanking assemblies 40 form bending areas 10 b. The area of the battery cell 10 corresponding to the two blanking assemblies 40 is opposite to the relief groove 20a of the winding needle 20. A flat area is formed between the two bending areas 10 b.

In some embodiments, referring to fig. 4, the heating assembly 30 further comprises a drive member 33. The pressing member 32 is connected to the driving member 33. The driving member 33 is configured to drive the pressing member 32 closer to or away from the winding needle 20. The pressing member 32 maintains a predetermined distance from the winding needle 20 before the first pole piece 11, the second pole piece 12 and the diaphragm 13 jointly enter the winding needle 20. After the first pole piece 11, the second pole piece 12 and the diaphragm 13 enter the winding needle 20 together, the driving part 33 drives the pressing part 32 to contact with the winding start ring 10a and apply a predetermined pressure. When the pressure applied to the heating area of the winding start ring 10a is less than the predetermined pressure, the extrusion force applied to at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 does not meet the predetermined pressure requirement, so that the adhesion firmness of the molten part of at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 does not meet the predetermined requirement, and further, the separation of at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 occurs again after the thermal compounding is completed. When the pressure applied to the heating region of the winding start coil 10a is greater than the predetermined pressure, there is a possibility that the pressing force applied to the winding start coil 10a exceeds the predetermined pressure requirement, and at least one of the first pole piece 11, the second pole piece 12, and the diaphragm 13 is excessively stressed to cause structural damage. Therefore, the driving part 33 can improve the accuracy of the pressure applied by the pressing part 32 to the winding start ring 10a, which is beneficial to reducing the error between the pressure applied to the winding start ring 10a and the predetermined pressure value, and reducing the possibility that at least one of the first pole piece 11 and the second pole piece 12 is separated again after thermal compounding with the diaphragm 13 or at least one of the first pole piece 11, the second pole piece 12 and the diaphragm 13 is structurally damaged. In some examples, a compressive stress of 3 megapascals (MPa) or more and 10 megapascals or less is applied to the heating region of the winding start coil 10a during the thermal compounding. Illustratively, a compressive stress of 7 mpa is applied to the heating region of the winding start coil 10 a.

In some embodiments, drive member 33 includes a mount 331 and a telescoping member 332. Telescoping member 332 is configured to drive mount 331 toward or away from winding needle 20. The pressing member 32 is disposed on the mounting seat 331. The telescopic member 332 drives the pressing member 32 to approach or separate from the winding needle 20 through the telescopic motion. The telescopic member 332 can provide a better restraining effect for the pressing member 32 on the side of the pressing member 32 away from the winding needle 20, so as to reduce the pressure fluctuation applied to the winding start ring 10a caused by the movement of the pressing member 32 in the direction away from the winding needle 20. Illustratively, the telescoping direction of the telescoping member 332 may be aligned with the center of rotation of the winding needle 20. Illustratively, the driving member 33 may be a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder. Telescoping member 332 comprises a piston and a piston rod. The mounting seat 331 is disposed on the piston rod.

In some embodiments, referring to fig. 5, the heating assembly 30 heats the entire winding start coil 10a to thermally compound at least one of the first and

second pole pieces

11 and 12 of the entire winding start coil 10a with the separator 13. In the completely wound battery cell 10, the interconnection between the separator 13 and at least one of the first pole piece 11 and the second pole piece 12 of the winding start ring 10a further reduces the possibility that the separator 13 is deformed by retraction or the end of the winding start ring 10a collapses, which results in an increase in the gap between the first pole piece 11 and the second pole piece 12.

In some embodiments, the heater 31 is provided to the pressing member 32. The heater 31 heats a predetermined position of the winding start coil 10a by the pressing member 32. The driving part 33 may drive the heater 31 and the pressing member 32 to simultaneously approach or separate from the winding pin 20. The heater 31 may heat the pressing member 32 to a predetermined temperature in advance. After the first pole piece 11, the second pole piece 12 and the diaphragm 13 enter the winding needle 20 together, the driving part 33 drives the pressing part 32 to contact with the winding start ring 10a and apply a predetermined pressure, and the pressing part 32 heats the winding start ring 10 a. Since the heater 31 is disposed on the pressing member 32, the heater 31 can heat the pressing member 32 in real time, thereby ensuring that the temperature of the pressing member 32 is always kept at a predetermined temperature, and reducing the possibility of thermal recombination failure or poor effect caused by large fluctuation of the temperature of the pressing member 32.

In some embodiments, referring to FIG. 6, the heating assembly 30 begins to thermally compound a region of the winding initiation coil 10a on a side of the relief groove 20a proximate the first half-shaft 21. Then, the winding pin 20 rotates to make the abdication groove 20a of the first half shaft 21 pass through the pressing piece 32, and the heating assembly 30 finishes the thermal compounding after finishing the thermal compounding to the other side area of the winding start ring 10a close to the abdication groove 20a of the first half shaft 21. Referring to fig. 7, the winding pin 20 is then rotated such that the relief groove 20a of the second half shaft 22 is rotated to the heating unit 30. The heating assembly 30 starts thermal recombination again for a region on the winding start coil 10a side close to the relief groove 20a of the second half shaft 22. Then, the winding pin 20 rotates to enable the abdication groove 20a of the second half shaft 22 to pass through the pressing piece 32, and the heating assembly 30 finishes the thermal compounding after the thermal compounding is finished on the other side area of the winding starting ring 10a close to the abdication groove 20a of the second half shaft 22. The heating assembly 30 thermally compounds two regions of the winding start coil 10a opposite to the relief grooves 20a, and the thermally compounded regions of the winding start coil 10a cover the relief grooves 20a of the first half shaft 21 and the second half shaft 22. The two heat-recombination regions on the winding start circle 10a form the bending regions 10b when the subsequent electrical core 10 is stretched to be flat.

In some embodiments, the press 32 is a press roll. When the pressing member 32 presses against the winding start ring 10a, the pressing member 32 can rotate along with the rotation of the winding needle 20, so that the heating assembly 30 can continuously perform thermal compounding on the winding start ring 10a, the winding needle 20 does not need to stop rotating, the thermal compounding consistency and stability of the winding start ring 10a are improved, and the thermal compounding work efficiency is also improved. Since the pressing member 32 is a rotational body, the pressing member 32 can accommodate winding pins 20 of different shapes, such as circular winding pins, rhombic winding pins, or elliptical winding pins. The pressing member 32 is rotatably connected to the mounting base 331. The axis of rotation of the pressing member 32 is parallel to the axis of rotation of the winding needle 20.

In some examples, the press 32 is a hollow structure. The pressing member 32 has an inner accommodation space. At least part of the heater 31 is accommodated inside the pressing member 32. The pressing member 32 may cover the heater 31 in the circumferential direction of the heater 31 to protect the heater 31 and reduce the possibility of damage to the heater 31. The heater 31 is disposed inside the pressing member 32, so that the heater 31 can easily keep the heating state of each region of the pressing member 32 consistent, thereby ensuring that the temperature rise of each region of the pressing member 32 is consistent, which is beneficial to reducing the possibility that the heating effect of the diaphragm 13 of the battery cell 10 is different due to the uneven temperature of the region where the pressing member 32 contacts the battery cell 10, and further reducing the possibility that at least one of the first pole piece 11 and the second pole piece 12 is adhered to the diaphragm 13 in the heating region to different degrees.

In some examples, referring to fig. 8, the pressing member 32 is a press roller. The heater 31 is provided inside the pressing member 32. The heater 31 may be connected to an external control circuit through the conductive slip ring 50, so that the control circuit may control the heater 31 to heat the pressing member 32 in real time when the heater 31 and the pressing member 32 rotate synchronously.

In some embodiments, as shown with reference to fig. 8, the heating assembly 30 further includes an anti-adhesive member 36. At least part of the outer surface of the pressing member 32 covers the anti-sticking member 36. The anti-sticking member 36 is configured to abut the winding start coil 10 a. When the heater 31 heats the winding start coil 10a through the pressing member 32 after heating the pressing member 32, since the anti-sticking member 36 provided on the pressing member 32 has an anti-sticking effect, the heating member 30 is less likely to stick to the winding start coil 10a, and the possibility that the heating member 30 pulls the winding start coil 10a due to the sticking of the heating member 30 to the winding start coil 10a is reduced. Illustratively, the release member 36 is formed by applying a release material over the press element 32 using a coating process. Illustratively, the material of the anti-sticking member 36 includes an anti-sticking material such as teflon.

In some embodiments, referring to fig. 9, the pressing member 32 is a press block. After the first pole piece 11, the second pole piece 12 and the diaphragm 13 enter the winding needle 20, the winding needle 20 stops rotating, and the pressing member 32 presses against the winding start ring 10a to apply a predetermined pressure to the winding start ring 10a, so that the first pole piece 11, the second pole piece 12 and the diaphragm 13 complete thermal compounding. Then, the pressing member 32 moves away from the winding needle 20, and the winding needle 20 starts to rotate again to continue winding. Illustratively, the pressing member 32 is used for pressing the winding start ring 10a to match the outer surface shape of the winding needle 20. The winding needle 20 may be, but is not limited to, a circular winding needle, a diamond winding needle, or an oval winding needle. When the pressing member 32 applies pressure to the winding start ring 10a, the winding needle 20 remains stationary, so that there is no relative displacement between the winding needle 20 and the pressing member 32, and the possibility of at least one of the first pole piece 11, the second pole piece 12 and the diaphragm 13 being wrinkled due to the relative movement between the pressing member 32 and the winding start ring 10a can be reduced. Illustratively, the pressing member 32 is detachably connected to the mounting seat 331.

In some embodiments, referring to fig. 10, the heating assembly 30 further includes a first temperature sensor 34. The first temperature sensor 34 is configured to monitor the temperature of the pressing member 32. The temperature at which the separator 13 melts needs to be controlled at a predetermined temperature to achieve a good thermal recombination effect. If the temperature is too high, the separator 13 may be damaged by burning. If the temperature is too low, there is a possibility that the separator 13 cannot be brought into a molten state to cause thermal recombination failure. The temperature of the pressing element 32 can be monitored in real time through the first temperature sensor 34, so that whether the temperature of the pressing element 32 is at a preset temperature or not can be conveniently judged, and the possibility that the thermal compound effect is poor due to the fact that the temperature of the pressing element 32 is too high or too low can be reduced. The heater 31 can be started or stopped in real time according to the temperature signal acquired by the first temperature sensor 34, so that the temperature of the pressing member 32 is always kept at the preset heating temperature, the consistency of the heat recombination effect can be ensured, and the heat recombination efficiency can be improved. Illustratively, the first temperature sensor 34 is disposed at the mount 331.

In some embodiments, the heater 31 may be disposed on the mounting seat 331 and spaced apart from the pressing member 32. The heater 31 does not need to follow the rotation of the pressing member 32, thereby reducing the difficulty in designing the structure of the heater 31 and the control circuit connected to the heater 31.

In some embodiments, referring to fig. 11, the heater 31 is disposed inside the winding needle 20 and configured to heat a region of the winding needle 20 opposite to a predetermined position of the winding start circle 10 a. The heater 31 may heat the winding needle 20 so that the temperature of the region of the winding needle 20 opposite to the predetermined position of the winding start circle 10a reaches a predetermined temperature. After the first pole piece 11, the second pole piece 12 and the diaphragm 13 enter the winding needle 20, the heated region of the winding needle 20 can heat the winding start ring 10a, and then the pressing member 32 applies a predetermined pressure to the heated region on the winding start ring 10a to thermally compound the winding start ring 10 a. Because the heater 31 is arranged inside the winding needle 20, the winding needle 20 can continuously rotate, and the end part of the winding starting ring 10a, different areas of the winding starting ring 10a or the whole winding starting ring 10a is thermally compounded in the rotating process, thereby effectively improving the winding work efficiency. For example, the heater 31 may heat a region of the winding needle 20 opposite to a predetermined position of the winding start circle 10a to a predetermined temperature while the winding needle 20 is in a stationary state. The heater 31 stops operating. The winding needle 20 is activated to wind the first pole piece 11, the second pole piece 12 and the separator 13.

In some embodiments, the heating assembly 30 further comprises a second temperature sensor 35. The second temperature sensor 35 is provided to the winding pin 20. The second temperature sensor 35 is configured to monitor the temperature of the region on the winding needle 20 opposite to the predetermined position of the winding start circle 10 a. The temperature at which the separator 13 melts needs to be controlled at a predetermined temperature to achieve a good thermal recombination effect. If the temperature is too high, the separator 13 may be damaged by burning. If the temperature is too low, there is a possibility that the separator 13 cannot be brought into a molten state to cause thermal recombination failure. The second temperature sensor 35 can monitor the temperature of the area of the winding needle 20 opposite to the preset position of the winding start ring 10a in real time, so as to conveniently judge whether the temperature of the area of the winding needle 20 opposite to the preset position of the winding start ring 10a is at the preset temperature, and the possibility of poor thermal compound effect caused by the fact that the local temperature of the winding needle 20 is higher or lower is favorably reduced.

In some embodiments, the outer periphery of the winding needle 20 has a relief groove 20a for blanking the battery cell 10. Along the circumferential direction of the winding needle 20, heaters 31 are provided on both sides of the relief groove 20 a. After the winding start coil 10a is heated by the heaters 31 on both sides, two thermal compound regions can be formed on the winding start coil 10 a. The two thermal recombination regions are respectively positioned at two sides of the abdicating groove 20 a. The portion of the winding start ring 10a covering the relief grooves 20a on the first half shaft 21 and the second half shaft 22 forms a bending region 10b when the subsequent battery core 10 is stretched to be flat, so that the heater 31 heats the winding start ring 10a and two thermal compound regions formed by pressing the winding start ring 10a by the pressing member 32 are located in the bending region 10b or close to the bending region 10b, which is beneficial to reducing the possibility that the diaphragm 13 of the bending region 10b drives the first pole piece 11 or the second pole piece 12 to move inward. Illustratively, the heater 31 is spaced from the outer surface of the winding needle 20 by a distance of 5 mm to 230 mm.

In some examples, the heater 31 is provided on one of both sides of the escape groove 20a in the circumferential direction of the winding needle 20.

Referring to fig. 12, an embodiment of the present application further provides a method for manufacturing a battery cell 10, which includes:

winding the first pole piece 11, the diaphragm 13 and the second pole piece 12 of the battery cell 10 to form a winding starting ring 10 a;

the predetermined position of the winding start coil 10a is heated to thermally compound at least one of the first and

second pole pieces

11 and 12 at the predetermined position with the separator 13.

In some embodiments, the battery cell 10 may be the battery cell 10 of the above-described embodiments. The wound battery cell 10 is stretched into a flat shape. Then, the flat battery cell 10 is subjected to a pre-press molding.

The method for manufacturing the battery cell 10 according to the embodiment of the present application is used to manufacture the battery cell 10 according to the embodiment described above. In the method for manufacturing the battery cell 10 according to the embodiment of the present application, the first pole piece 11, the second pole piece 12, and the separator 13 are wound to form the battery cell 10. The predetermined position of the winding start coil 10a is heated to thermally compound at least one of the first and

second pole pieces

11, 12 with the diaphragm 13 in the predetermined position, so that the diaphragm 13 is no longer in a free state, but is constrained by the first and/or

second pole pieces

11, 12. Because the diaphragm 13 at the inner ring part is restrained, the diaphragm 13 at the inner ring part is not easy to retract, so that the possibility that the first pole piece 11 and the second pole piece 12 are driven to move inwards due to the retraction of the diaphragm 13, the gap between the first pole piece 11 and the second pole piece 12 at the inner ring part is too large, and the possibility of lithium precipitation is reduced.

In some embodiments, the heating time for the predetermined position of the winding start coil 10a is 2 seconds to 5 seconds. When the heating time is less than 2 seconds, there is a possibility that the heating time is short and the degree of melting of the separator 13 does not meet a predetermined requirement, thereby causing poor thermal recombination effect or thermal recombination failure. If the heating time is longer than 5 seconds, the heating time may be long, and the degree of melting of the separator 13 may exceed a predetermined level, which may cause breakage of the separator 13 and failure of the separator 13.

In some embodiments, the heating temperature for the predetermined position of the winding start coil 10a is 85 to 95 degrees. When the heating temperature is lower than 85 degrees, there is a possibility that the heating temperature is low and the degree of melting of the separator 13 does not meet a predetermined requirement, thereby causing poor thermal recombination effect or failure of thermal recombination. When the heating temperature is higher than 95 degrees, the heating temperature is high, and the degree of melting of the separator 13 exceeds a predetermined level, and the separator 13 may be broken and the separator 13 may fail.

In some embodiments, when the predetermined position of the winding start ring 10a is heated, pressure is applied to the predetermined position of the winding start ring 10a, so that the first pole piece 11 and/or the second pole piece 12 can be bonded with the molten part of the diaphragm 13 under the action of the pressure, and it can be ensured that at least one of the first pole piece 11 and the second pole piece 12 successfully completes thermal compounding with the diaphragm 13 and that the connection state is stable and reliable.

In some examples, the predetermined position of the winding start coil 10a is applied with a pressure of 3 mpa or more and 10 mpa or less. When the compressive stress applied to the heating region of the winding start ring 10a is less than 3 mpa, the extrusion force applied to at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 does not meet the predetermined pressure requirement, so that the adhesion firmness of the molten part of at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 does not meet the predetermined requirement, and further, the separation of at least one of the first pole piece 11 and the second pole piece 12 and the diaphragm 13 is likely to occur again after the thermal compounding is completed. When the compressive stress applied to the heating region of the winding start coil 10a is greater than 10 mpa, the pressing force applied exceeds a predetermined pressure requirement, and thus at least one of the first pole piece 11, the second pole piece 12, and the separator 13 may be subjected to an excessive force to cause structural damage. Illustratively, in the thermal compounding step, a compressive stress of 7 mpa is applied to the heating region of the winding start coil 10 a.

While the present application has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present application, and in particular, features shown in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. A cell manufacturing apparatus, the cell including a first pole piece, a second pole piece, and a separator, the cell having a winding start circle located inside, the cell manufacturing apparatus comprising:

a winding needle configured to wind the first pole piece, the second pole piece and the diaphragm to form the battery cell, wherein in an initial winding stage of the winding needle, the winding start ring is wound on the periphery of the winding needle;

a heating assembly configured to heat a predetermined location of the winding start turn to thermally compound at least one of the first and second pole pieces at the predetermined location with the diaphragm;

wherein the heating component comprises a heater and a pressing piece, the heater is configured to heat the preset position, the pressing piece is arranged on the outer side of the winding needle, and the pressing piece is configured to be co-extruded with the winding needle to the preset position so as to apply pressure to the preset position.

2. The cell manufacturing apparatus according to claim 1, wherein the heating assembly further comprises a driving member, the pressing member is connected to the driving member, and the driving member is configured to drive the pressing member to approach or move away from the winding pin.

3. The battery cell manufacturing apparatus according to claim 2, wherein the driving component includes a mounting seat and a telescopic member, the telescopic member is configured to drive the mounting seat to approach or separate from the winding pin, and the pressing member is disposed on the mounting seat.

4. The battery cell manufacturing apparatus according to claim 1, wherein the heater is provided to the pressing member, and the heater heats the predetermined position through the pressing member.

5. The cell manufacturing apparatus according to claim 4, wherein the heating assembly further includes a first temperature sensor configured to monitor a temperature of the pressing member.

6. The cell manufacturing device according to claim 4 or 5, wherein the pressing member is a hollow structure, and at least part of the heater is accommodated inside the pressing member.

7. The cell manufacturing apparatus of claim 1, wherein the heater is disposed inside the winding pin and configured to heat an area of the winding pin opposite the predetermined location.

8. The cell manufacturing apparatus of claim 7, wherein the heating assembly further comprises a second temperature sensor disposed on the winding pin, the second temperature sensor configured to monitor a temperature of an area of the winding pin opposite the predetermined location.

9. The battery cell manufacturing apparatus according to claim 7, wherein the winding pin has an abdicating groove at its periphery for blanking the battery cell, and the heater is disposed on at least one of two sides of the abdicating groove along the circumferential direction of the winding pin.

10. The cell manufacturing apparatus according to any one of claims 1 to 5 and 7 to 9, wherein the heating assembly further includes an anti-adhesion member, at least a part of an outer surface of the pressing member covers the anti-adhesion member, and the pressing member applies pressure to the predetermined position through the anti-adhesion member.

11. The battery cell manufacturing device according to any one of claims 1 to 5 and 7 to 9, wherein the pressing member is a pressing roller or a pressing block matched with the shape of the winding needle.

12. A method of manufacturing a cell, comprising:

winding the first pole piece, the diaphragm and the second pole piece of the battery cell by using a winding needle to form a winding starting ring;

heating a predetermined position of the winding start coil using a heating assembly to thermally compound at least one of the first and second pole pieces and the separator at the predetermined position;

13. The cell manufacturing method according to claim 12, wherein the predetermined position of the winding start circle is heated for 2 to 5 seconds; and/or, when the preset position of the winding starting ring is heated, the heating temperature is 85-95 degrees.

14. The cell manufacturing method of claim 12, wherein when the predetermined position of the winding start circle is heated, pressure is applied to the predetermined position.

15. The cell manufacturing method of claim 14, wherein the pressure is greater than or equal to 3 mpa and less than or equal to 10 mpa.