Winding core, battery, method for manufacturing winding core, and method for manufacturing battery

Abstract

The application belongs to the technical field of batteries, and provides a winding core, a battery, a manufacturing method of the winding core and a manufacturing method of the battery. The winding core comprises a support, two pole pieces and two separators. The two pole pieces and the two separators are alternately stacked and wound. The two pole pieces are respectively used for electrically connecting positive and negative tabs. The support is clamped between an adjacent pole piece and a separator. The support is arranged from one side of the width direction of the pole piece to the other side of the width direction of the pole piece. At least one end of the support extends to the edge of the width direction of the pole piece. The support comprises a phase change material structure and / or a shape memory alloy structure. The phase change material structure and / or the shape memory alloy structure are used for phase change and / or deformation when the temperature of the battery rises to a predetermined temperature range, so as to form a pressure relief channel which is in communication with the outside of the winding core between the pole piece and the separator adjacent to the support. The winding core provided by the application can quickly release the internal pressure of the winding core after the temperature reaches the predetermined temperature range, so as to avoid explosion of the winding core and the battery as much as possible.

Description

Technical Field

[0001] This application relates to the field of battery technology, and specifically to a winding core, a battery, a method for manufacturing the winding core, and a method for manufacturing the battery. Background Technology

[0002] Batteries typically consist of a casing and a core. The casing has a cavity, and the core is installed inside the cavity. When a battery experiences a short circuit, thermal runaway, or other safety issues, a large amount of gas is generated inside the core. This gas is released into the cavity, increasing the pressure within it. If the pressure inside the cavity becomes too high, the battery is prone to explosion. To prevent a sudden increase in internal pressure that could lead to an explosion, current technology typically includes a pressure relief valve on the battery casing. When the battery is improperly charged, short-circuited, or exposed to harsh environments such as high temperatures, the gas released from the core into the cavity can open the valve when the pressure inside reaches a certain value, thus releasing pressure and improving battery safety.

[0003] However, batteries with the above structure cannot quickly release the internal pressure of the core into the accommodating cavity. When the internal pressure of the core accumulates too high, there is also a risk of battery explosion. Summary of the Invention

[0004] The purpose of this application is to provide a winding core, a battery, a method for manufacturing the winding core, and a method for manufacturing the battery, so as to solve the technical problem in the prior art that the internal pressure of the winding core cannot be released quickly, which can easily lead to the battery exploding.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: a core is provided for a battery. The core includes a support member, two electrodes, and two separators. The two electrodes and two separators are alternately stacked and wound together. The two electrodes are respectively used to electrically connect a positive electrode tab and a negative electrode tab. The support member is sandwiched between an adjacent electrode and a separator, and the support member is arranged along one side of the width direction of the electrode to the other side of the width direction of the electrode. At least one end of the support member extends to the edge of the width direction of the electrode. The support member includes a phase change material structure and / or a shape memory alloy structure, which is used to undergo phase change and / or deformation after the temperature of the battery rises to a predetermined temperature range, thereby forming a pressure relief channel communicating with the outside of the core between the electrode and the separator adjacent to the support member.

[0006] In one embodiment, the phase change material structure is a paraffin strip, and the melting point of the paraffin strip is 62°C-64°C.

[0007] In one embodiment, the shape memory alloy structure is a nickel-titanium shape memory alloy strip, and the deformation temperature of the nickel-titanium shape memory alloy strip is 60℃-70℃.

[0008] In one embodiment, the support includes a shape memory alloy structure, which is a strip structure when the temperature is below the deformation temperature, and at least one side of the shape memory alloy structure in the width direction is bent toward the electrode adjacent to the shape memory alloy or toward the diaphragm adjacent to the shape memory alloy when the temperature is above the deformation temperature.

[0009] In one embodiment, the number of supports is multiple, some of the supports are phase change material structures, and other supports are shape memory alloy structures. The shape memory alloy structures have a two-way shape memory effect, and the minimum deformation temperature of the shape memory alloy structures is lower than the minimum melting point of the phase change material structures.

[0010] In one embodiment, there are multiple supports, which are spaced apart along the length of the electrode.

[0011] In one embodiment, the support extends in a straight line or a curve.

[0012] In one embodiment, the area of ​​the cross-section of the support member remains constant along the length direction of the support member, changes unidirectionally, or decreases first and then increases.

[0013] In one embodiment, the cross-section of the support member is any one of a triangle, rectangle, trapezoid, semicircle, or semi-ellipse.

[0014] In one embodiment, the support is arranged between an adjacent electrode and a diaphragm along the width direction of the electrode, or the support is arranged obliquely between an adjacent electrode and a diaphragm relative to the width direction of the electrode.

[0015] To achieve the above objectives, this application also provides a method for manufacturing a core, the method comprising the following steps:

[0016] Prepare positive current collector, negative current collector, positive electrode material, negative electrode material and separator; prepare phase change material and / or shape memory alloy material.

[0017] Two electrodes are prepared using the positive current collector, the negative current collector, the positive electrode material, and the negative electrode material.

[0018] The support component is prepared using a phase change material and / or a shape memory alloy material;

[0019] The two electrodes and two diaphragms are alternately stacked and arranged, and the two alternately stacked diaphragms and two electrodes are wound from the starting end to the tail end. When the winding reaches a predetermined position, the support member is clamped between an adjacent electrode and a diaphragm, such that the support member is arranged along one side of the width direction of the electrode to the other side of the width direction of the electrode, and at least one end of the support member extends to the edge of the width direction of the electrode.

[0020] In one embodiment, the steps for preparing the two electrodes include:

[0021] The positive electrode material is intermittently or continuously coated on the surface of the positive electrode current collector, and the negative electrode material is intermittently or continuously coated on the surface of the negative electrode current collector;

[0022] The positive current collector coated with the positive electrode material and the negative current collector coated with the negative electrode material are rolled and slit.

[0023] In one embodiment, when the support is a phase change material structure, the step of preparing the support includes:

[0024] Prepare phase change materials;

[0025] The solid phase change material is melted into a liquid state at a temperature higher than the melting point of the phase change material, and a first intermediate structure with a first predetermined thickness is formed by extrusion; or the solid phase change material is cut into a first intermediate structure with a first predetermined thickness.

[0026] The first intermediate structure is pressed into a second intermediate structure with a second predetermined thickness by a roll forming method, wherein the second predetermined thickness is less than the first predetermined thickness;

[0027] The second intermediate structure is cut into a structure with a length of a first predetermined length, a width of a first predetermined width, and a shape of a first predetermined shape to produce the phase change material structure.

[0028] In one embodiment, when the support is a shape memory alloy structure, the steps for manufacturing the support include:

[0029] Prepare sheet-like shape memory alloy materials;

[0030] At a temperature below the deformation temperature of the shape memory alloy material, the shape memory alloy material is cut into a structure with a second predetermined length, a second predetermined width, a third predetermined thickness, and a second predetermined shape to form the phase change material structure.

[0031] To achieve the above objectives, this application also provides a battery, the battery including a casing and the aforementioned winding core, the casing having a housing and a pressure relief valve, the housing having a receiving cavity and a through hole communicating with the receiving cavity, the receiving cavity being used to install the winding core, and the through hole being used to install the pressure relief valve.

[0032] To achieve the above objectives, this application also provides a method for manufacturing a battery, the method comprising the following steps:

[0033] Prepare positive current collector, negative current collector, positive electrode material, negative electrode material, separator, electrolyte, shell and phase change material;

[0034] Two electrodes are prepared using the positive current collector, the negative current collector, the positive electrode material, and the negative electrode material.

[0035] The support component is prepared using a phase change material.

[0036] The winding process involves alternately stacking two electrode sheets and two diaphragms, and winding the alternately stacked diaphragms and two electrode sheets from the starting end to the tail end. When the winding reaches a predetermined position, the support member is filled between an adjacent diaphragm and an electrode sheet, such that the support member is arranged along one side of the width direction of the electrode sheet to the other side of the width direction of the electrode sheet, and at least one end of the support member extends to the edge of the width direction of the electrode sheet to form the core.

[0037] Electrolyte injection is performed by installing the winding core into the accommodating cavity and injecting the electrolyte into the accommodating cavity to wet the winding core, thereby producing a semi-finished battery.

[0038] Sealing: The semi-finished battery is sealed to form a battery;

[0039] The battery is then subjected to its first charge and discharge cycle after formation.

[0040] The battery was then charged and discharged sequentially at 0.2C, 0.5C, and 1.0C.

[0041] The beneficial effects of the winding core, battery, and manufacturing method of the winding core and battery provided in this application are as follows: Compared with the prior art, in the winding core provided in this application, when the support member includes a phase change material structure, after the battery temperature reaches a predetermined temperature range, the phase change material structure gradually melts. Since at least one end of the support member extends to the edge of the electrode in the width direction, the space originally occupied by the phase change material structure inside the winding core will form a pressure relief channel communicating with the external space of the winding core. The gas generated inside the winding core can be quickly released to the outside of the winding core along this pressure relief channel, reducing the risk of battery explosion. When the support member includes a shape memory alloy structure, after the battery temperature reaches a predetermined temperature range, the shape memory alloy structure deforms and expands the diaphragm and electrode adjacent to the support member. The expanded diaphragm and electrode form a pressure relief channel communicating with the outside of the winding core, allowing the gas generated inside the winding core to be quickly released to the outside of the winding core. The pressure is rapidly released to the outside of the core through the pressure relief channel, reducing the risk of battery explosion. When the support includes both a phase change material structure and a shape memory alloy structure, after the battery temperature reaches a predetermined temperature range, the phase change material structure gradually melts, and the space originally occupied by the phase change material structure connects with the external space of the core. Furthermore, the shape memory alloy structure deforms, opening up the diaphragm and electrode adjacent to the support. The space originally occupied by the phase change material structure and the space opened up by the shape memory alloy structure together form a pressure relief channel connecting to the outside of the core. Gas generated inside the core can be rapidly released to the outside of the core through the pressure relief channel, reducing the risk of battery explosion. Therefore, the core provided in this application can rapidly release internal pressure after the battery temperature reaches a predetermined temperature range, minimizing the risk of core and battery explosion and improving battery safety.

[0042] In addition, since the phase change material structure does not undergo phase change when the temperature of the core is below the predetermined temperature range, and the shape memory alloy structure does not undergo deformation when the temperature of the core is below the predetermined temperature range, the support is fixedly sandwiched between an adjacent electrode and a diaphragm when the temperature is below the predetermined temperature range. The electrode near the support does not collapse or deform, which can ensure the service life of the core. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the core structure of some embodiments of this application, showing the state when the electrode sheet and the diaphragm are stacked;

[0045] Figure 2 for Figure 1 A top view of the support structure of the core and one of the two pole pieces shown.

[0046] Figure 3 This is a schematic diagram of the core structure of some embodiments of this application, showing the state when the electrode sheet and diaphragm are wound, and the state when the support member is a phase change material structure and the phase change material structure has not undergone a phase change;

[0047] Figure 4 for Figure 3 Enlarged view of point A in the structural schematic diagram of the shown core;

[0048] Figure 5 This is a schematic diagram of the core structure of some embodiments of this application, showing the state when the electrode and diaphragm are wound, and the state when the support is a phase change material structure and the phase change material structure has undergone a phase change;

[0049] Figure 6 for Figure 5 An enlarged view of section B in the schematic diagram of the core structure shown;

[0050] Figure 7 This is a schematic diagram of the core structure of some embodiments of this application, showing the state when the electrode and diaphragm are wound, and the state when the support is a shape memory alloy structure and the shape memory alloy structure has not been deformed;

[0051] Figure 8 for Figure 7 An enlarged view of section C in the structural schematic diagram of the shown core;

[0052] Figure 9 This is a schematic diagram of the core structure of some embodiments of this application, showing the state when the electrode and diaphragm are wound, and the state when the support is a shape memory alloy structure and the shape memory alloy structure has been deformed;

[0053] Figure 10 for Figure 9 An enlarged view of point D in the schematic diagram of the core structure shown;

[0054] Figure 11 Schematic diagrams of the electrode structure of some embodiments of this application show that the support member extends in a curved shape;

[0055] Figure 12 Schematic diagrams of the electrode structure of some embodiments of this application show that the size of the cross-sectional area of ​​the support member varies unidirectionally with the width direction of the electrode.

[0056] Figure 13Schematic diagrams of the electrode structure of some embodiments of this application show that the cross-sectional area of ​​the support member first decreases and then increases with the width direction of the electrode.

[0057] The following are the labeling elements in the figure:

[0058] 10-Core; 100-Support component; 110-Phase change material structure; 120-Shape memory alloy structure; 200-Electrode sheet; 201-Pressure relief channel; 211-Positive current collector; 212-Positive electrode material; 221-Negative current collector; 222-Negative electrode material; 300-Separator. Detailed Implementation

[0059] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0060] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0062] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, and not all refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner.

[0063] Please see Figure 1 and Figure 2The core 10 provided in this application embodiment will now be described. The core 10 is used in a battery and includes a support member 100, two electrode sheets 200, and two separators 300. The two electrode sheets 200 and two separators 300 are alternately stacked and wound together. The two electrode sheets 200 are respectively used for electrically connecting the positive electrode tab and the negative electrode tab. The support member 100 is sandwiched between adjacent electrode sheets 200 and separators 300. The support member 100 is arranged along one side of the width direction W of the electrode sheet 200 to the other side of the width direction W of the electrode sheet 200. At least one end of the support member 100 extends to the edge of the width direction W of the electrode sheet 200. Specifically, Figure 2 The support member 100 shown in the figure extends to the edges of both sides of the electrode 200 in the width direction W, where the width direction W of the electrode 200 is... Figure 2 The W direction is shown; the support member 100 includes a phase change material structure 110 and / or a shape memory alloy structure 120, which are used to form a pressure relief channel 201 communicating with the outside of the winding core 10 between the separator 300 and the electrode 200 adjacent to the support member 100 after the battery temperature rises to a predetermined temperature range and / or after the core 10 temperature rises to a predetermined temperature range.

[0064] Specifically, the support member 100 can extend in a straight line or in a curved line (see [reference]). Figure 11 The cross-section of the support member 100 can be any one of the following: triangle, rectangle, trapezoid, semicircle, or semi-ellipse.

[0065] Specifically, the minimum value of the predetermined temperature range is greater than or equal to the upper working temperature T1 of the core 10, the maximum value of the predetermined temperature range is less than the thermal instability temperature T2 of the core 10, and the predetermined temperature range is related to the phase transformation temperature T3 of the phase transformation material structure 110 and the deformation temperature T4 of the shape memory alloy material. For example, if the support member 100 only includes a phase change material structure 110, and the phase change temperature T3 of the phase change material structure 110 is a temperature range, then the predetermined temperature range is the phase change temperature T3 of the phase change material structure 110; if the support member 100 only includes a shape memory alloy structure 120, and since the deformation temperature T4 of the shape memory alloy material is a temperature range, then the predetermined temperature range is the deformation temperature T4 of the shape memory alloy structure 120; if the support member 100 includes both a phase change material structure 110 and a shape memory alloy structure 120, when the battery reaches the phase change temperature T3 of the phase change material structure 110, the phase change material structure 110 begins to melt, and when the battery temperature reaches the deformation temperature T4 of the shape memory alloy structure 120, the shape memory alloy structure 120 begins to deform, then the predetermined temperature range may include both the phase change temperature T3 and the deformation temperature T4.

[0066] Compared with the prior art, the core 10 provided in this application, please refer to... Figures 3 to 6When the support member 100 only includes the phase change material structure 110, after the battery temperature reaches a predetermined temperature range, the phase change material structure 110 undergoes a phase change and melts. Since at least one end of the support member 100 extends to the edge of the electrode sheet 200 in the width direction, the space originally occupied by the phase change material structure 110 inside the core 10 will form a pressure relief channel 201 communicating with the external space of the core 10. Gas generated inside the core 10 can be quickly released to the outside of the core 10 along this pressure relief channel 201, reducing the risk of battery explosion; please refer to Figures 7 to 10 When the support member 100 includes a shape memory alloy structure 120, after the battery temperature reaches a predetermined temperature range, the shape memory alloy structure 120 deforms and expands the separator 300 and electrode 200 adjacent to the shape memory alloy structure 120. A pressure relief channel 201 communicating with the outside of the winding core 10 is formed between the expanded separator 300 and electrode 200. Gas generated inside the winding core 10 can be quickly released to the outside of the winding core 10 along this pressure relief channel 201, reducing the risk of battery explosion. When the support member 100 simultaneously includes a phase change material structure 110 and a shape memory alloy structure 120 (this case is not shown in the diagram), after the battery temperature reaches the phase change temperature of the phase change material structure 110, the phase change material structure 110 undergoes a phase change and melts. The original phase change material structure 110... The space between the core 10 and the external space of the winding core 10 is connected. After the battery temperature reaches the deformation temperature of the shape memory alloy structure 120, the shape memory alloy structure 120 deforms and expands the separator 300 and electrode 200 adjacent to the support member 100. The space originally occupied by the phase change material structure 110 and the space expanded by the shape memory alloy structure 120 together form a pressure relief channel 201 that is connected to the outside of the winding core 10. The gas generated inside the winding core 10 can be quickly released to the outside of the winding core 10 through the pressure relief channel 201, reducing the risk of battery explosion. It can be seen that the winding core 10 provided in this application can quickly release the internal pressure after the battery temperature reaches the predetermined temperature range, which can minimize the risk of explosion of the winding core 10 and the battery and improve the safety of the battery.

[0067] Additionally, please see Figure 3 , Figure 4 , Figure 7 and Figure 8 Since the phase change material structure 110 does not undergo phase change when the temperature is below the phase change temperature, and the shape memory alloy structure 120 does not undergo deformation when the temperature is below the deformation temperature, when the battery temperature is below the predetermined temperature range, the support member 100 is fixedly sandwiched between an adjacent electrode 200 and a separator 300. The electrode 200 near the support member 100 is not at risk of collapse or deformation, which can ensure the service life of the core 10.

[0068] In another embodiment of this application, please refer to Figures 7 to 10 The support member 100 includes a shape memory alloy structure 120, please refer to [link / reference]. Figure 7 and Figure 8 When the temperature is below the deformation temperature T4, the shape memory alloy structure 120 is a strip structure, sandwiched between an adjacent diaphragm 300 and an electrode 200. At this time, there is a very small gap or no gap between the diaphragm 300 and the electrode 200 adjacent to the shape memory alloy structure 120. (See also...) Figure 9 and Figure 10 When the temperature is higher than the deformation temperature T4, the shape memory alloy structure 120 bends at least one side in its width direction toward either the diaphragm 300 adjacent to the shape memory alloy structure 120 or the electrode 200 adjacent to the shape memory alloy structure 120. The width direction of the shape memory alloy structure 120 is the length direction L of the electrode 200 in its flat state. For example, both sides of the width direction of the shape memory alloy structure 120 bend toward the diaphragm 300 adjacent to the shape memory alloy structure 120. When the shape memory alloy structure 120 is bent, its cross-section forms a C-shape. In this case, the bent sides and arched middle of the shape memory alloy structure 120 can spread apart the adjacent electrode 200 and diaphragm 300, increasing the gap between them and forming a pressure relief channel 201 that communicates with the outside of the core 10. This allows gas generated inside the core 10 to be quickly released to the outside of the core 10 through this pressure relief channel 201, preventing the core 10 from exploding due to excessive internal pressure. Alternatively, if one side of the shape memory alloy structure 120 bends towards the adjacent electrode 200, this bending side can spread apart the adjacent electrode 200 and diaphragm 300, increasing the gap between them and forming a pressure relief channel 201 that communicates with the outside of the core 10.

[0069] Specifically, the shape memory alloy structure 120 can be a nickel-titanium shape memory alloy strip. The deformation temperature T4 of the nickel-titanium shape memory alloy strip is 60℃-70℃. After the temperature of the battery rises to 60℃, the nickel-titanium shape memory alloy strip gradually deforms from a strip structure into a structure in which at least one side in the width direction bends toward the electrode 200 or separator 300 adjacent to the shape memory alloy structure 120.

[0070] In another embodiment of this application, please refer to Figures 3 to 6 The support member 100 includes a phase change material structure 110, please refer to [link / reference]. Figure 3 and Figure 4When the temperature is below the phase change temperature T3, the phase change material structure 110 is a strip structure. At this time, the phase change material structure 110 is sandwiched between an adjacent diaphragm 300 and an electrode 200. The gap between the electrode 200 and the diaphragm 300 adjacent to the phase change material structure 110 is small or nonexistent, and the electrode 200 adjacent to the phase change material structure 110 has no risk of collapse. Please refer to [link / reference]. Figure 5 and Figure 6 When the temperature is higher than the phase change temperature, the phase change material structure 110 changes from a solid phase to a liquid phase. The space originally occupied by the solid phase change material structure 110 inside the core 10 is filled with the liquid phase. The space originally occupied by the phase change material structure 110 inside the core 10 forms a pressure relief channel 201. Gas can rush out from the pressure relief channel 201 to the outside of the core 10, which can minimize the risk of the core 10 exploding due to excessive internal pressure.

[0071] Specifically, the phase change material structure 110 can be a paraffin strip with a melting point of 62℃-64℃. When the temperature of the core 10 reaches 62℃, the paraffin strip gradually melts.

[0072] In another embodiment of this application, there are multiple support members 100. Some of the multiple support members 100 are phase change material structures 110, and the other part of the multiple support members 100 are shape memory alloy structures 120. The shape memory alloy structure 120 has a two-way shape memory effect, and the minimum value of the deformation temperature T4 of the shape memory alloy structure 120 is lower than the minimum value of the melting point of the phase change material structure 110.

[0073] Specifically, the phase transformation temperature T3, i.e. the melting point, of the phase change material structure 110 can be 64℃-70℃, and the deformation temperature T4 of the shape memory alloy structure 120 can be 60℃-63℃.

[0074] In the embodiments of this application, the wound core 10, when its temperature rises to the minimum value of the deformation temperature T4 of the shape memory alloy structure 120, begins to deform, spreading apart the separator 300 and electrode 200 adjacent to the shape memory alloy structure 120, thus forming a gap between them. Gas generated inside the wound core 10 can be released to the outside of the wound core 10 through this gap, which can minimize the risk of the wound core 10 exploding due to excessive internal pressure. If, after the shape memory alloy structure 120 deforms, the battery temperature further rises to the minimum value of the phase change material structure T3, the phase change material structure 110 will undergo phase change melting, connecting the space originally occupied by the phase change material structure 110 inside the wound core 10 with the outside of the wound core 10. The space originally occupied by the phase change material structure 110 can increase the pressure relief. The flow area of ​​channel 201 can further accelerate the release of gas generated inside the core 10 to the outside of the core 10, and give the core 10 a stepped internal pressure release capability. If, after the shape memory alloy structure 120 is deformed, the temperature of the core 10 does not rise further to the minimum melting point of the phase change material structure 110, but gradually decreases to the minimum value of the deformation temperature T4 of the shape memory alloy structure 120, then, due to the two-way shape memory effect of the shape memory alloy structure 120, the shape memory alloy structure 120 will gradually deform back to its original shape after the temperature is lower than the minimum value of the deformation temperature T4, that is, it will return to the state where it cannot expand the diaphragm 300 and the electrode 200 adjacent to the shape memory alloy structure 120, so that the core 10 still maintains the stepped internal pressure release capability and can continuously ensure the safety of the core 10.

[0075] In another embodiment of this application, please refer to Figure 2 The number of support members 100 is multiple, and the multiple support members 100 are arranged at intervals along the length direction L of the electrode 200, where the length direction L of the electrode 200 is... Figure 2 The L direction as described in the document.

[0076] Specifically, when the length of the electrode 200 is 600mm, support members 100 can be provided at positions 150mm, 300mm and 450mm away from the starting end of the electrode 200, that is, three support members 100 are provided at intervals along the length direction L of the electrode 200.

[0077] The winding core 10 provided in this application embodiment has multiple support members 100 arranged at intervals along the length direction L of the electrode sheet 200. After the electrode sheet 200 is wound, the winding core 10 will have support members 100 in multiple different areas. When the battery temperature rises to a predetermined temperature range, a venting channel can be formed in multiple different areas of the winding core 10. The gas inside the winding core 10 can be released simultaneously from the venting channels in different areas of the winding core 10, thereby improving the safety of the winding core 10.

[0078] In another embodiment of this application, please refer to Figure 2 The cross-sectional area of ​​the support member 100 remains constant along its length. The support member 100 is simple to manufacture. Please refer to [link / reference]. Figure 12 The cross-sectional area of ​​the support member 100 varies unidirectionally along the length of the support member 100, or, please refer to... Figure 13 The cross-sectional area of ​​the support member 100 first decreases and then increases along the length of the support member 100.

[0079] Specifically, please refer to Figure 13 The two ends of the support member 100 extend to the edges of the electrode 200 in the width direction. The cross-sectional area of ​​the support member 100 first decreases and then increases along the length direction of the support member 100. At this time, after the battery temperature reaches the predetermined temperature range, the support member 100 can form a pressure relief channel 201 with a small flow area in the middle and a large flow area at both ends inside the core 10. The resistance of the gas flowing from the middle to the end of the pressure relief channel 201 is small, which is conducive to the rapid release of the gas generated by the core 10 to the end of the core 10.

[0080] The core 10 provided in this embodiment is designed to vary the cross-sectional area of ​​the support member 100 based on parameters such as the working conditions of the core 10, the processing difficulty of the support member 100, and the pressure relief effect, so that the core 10 can be used in different occasions.

[0081] In another embodiment of this application, please refer to Figure 2 The support member 100 extends along the width direction W of the electrode 200. For example, when the electrode 200 is in a flat state, the support member 100 extends in a straight line along the width direction W of the electrode 200. With this arrangement, the gas inside the core 10 can be quickly released to the outside of the core 10 along a shorter path, which helps to reduce the risk of explosion of the core 10 and the battery.

[0082] In another embodiment of this application, please refer to Figure 11 The support member 100 is arranged inclined relative to the width direction of the electrode 200 between an adjacent electrode 200 and a diaphragm 300. For example, the support member 100 is arranged in an arc shape on the electrode 200 when the electrode 200 is laid flat. With this arrangement, after the electrode 200 is wound, the two ends of the support member 100 are located at different angles in the circumferential direction of the core 10. That is, the support member 100 has a large span in the circumferential direction of the core 10, which can protect the core 10 over a large range in the circumferential direction of the core 10, thus improving the safety of the core 10.

[0083] This application also provides a battery (not shown in the figure), which includes a casing (not shown in the figure) and the aforementioned core 10. The casing has a housing (not shown in the figure) and a pressure relief valve (not shown in the figure). The housing has a receiving cavity (not shown in the figure) and a through hole (not shown in the figure) communicating with the receiving cavity. The receiving cavity is used to install the core 10, and the through hole is used to install the pressure relief valve.

[0084] Specifically, the through hole can be set towards the end of the support 100, which is conducive to the gas quickly opening the pressure relief valve.

[0085] In the battery provided in this embodiment, a support member 100 is provided between adjacent electrode sheets 200 and separator 300 of the core 10. The support member 100 includes a phase change material structure 110 and / or a shape memory alloy structure 120. After the battery temperature rises to a predetermined temperature range, the phase change material structure 110 undergoes a phase change, causing the space originally occupied by the phase change material structure 110 within the core 10 to connect with the accommodating cavity, and / or, the shape memory alloy structure 120 deforms and expands to separate from the shape memory alloy structure 110. The gas generated inside the core 10, which is adjacent to the electrode 200 and the separator 300, can be released into the accommodating cavity through the space originally occupied by the phase change material structure 110 and / or the gap opened by the shape memory alloy structure 120. After the gas pressure in the accommodating cavity reaches a certain value, the gas in the accommodating cavity can open the pressure relief valve and be released to the outside of the casing, forming a complete and effective pressure relief path from the inside of the core 10 to the accommodating cavity, and then from the accommodating cavity to the outside of the battery, which can effectively improve the safety of the battery.

[0086] This application also provides a method for manufacturing a core 10, which includes the following steps:

[0087] S1: Prepare positive current collector 211, negative current collector 221, positive electrode material 212, negative electrode material 222 and separator 300, and prepare phase change material and / or shape memory alloy material.

[0088] Optionally, the positive electrode material 212 is a high-nickel ternary positive electrode material, the negative electrode material 222 is a silicon and graphite composite material, the separator 300 is polyethylene (PE), the upper limit operating temperature T1 of the core 10 is less than or equal to 60℃, the thermal runaway temperature T2 of the core 10 is the melting start temperature of the separator 300, and is greater than or equal to 120℃; the phase change material is fully refined paraffin wax 62#, and the phase change temperature T3 is 62℃-64℃; the shape memory alloy structure 120 is a nickel-titanium shape memory alloy with a nickel content of about 52%-60%, and is in sheet form at room temperature, with a phase change temperature T4 of 60℃-70℃.

[0089] S2: Prepare the two-electrode 200 by using a positive current collector 211, a negative current collector 221, a positive electrode material 212, and a negative electrode material 222.

[0090] Specifically, the steps for preparing the two electrodes 200 may include: S211: intermittently or continuously coating the surface of the positive electrode current collector 211 with positive electrode material 212 and intermittently or continuously coating the surface of the negative electrode current collector 221 with negative electrode material 222. S212: rolling and slitting the positive electrode current collector 211 coated with positive electrode material 212 and the negative electrode current collector 221 coated with negative electrode material 222.

[0091] S3: Prepare support 100 using phase change material and / or shape memory alloy material.

[0092] Specifically, the length of the support member 100 can be less than, equal to, or greater than the width of the corresponding electrode 200. The length of the support member 100 is the dimension of the support member 100 along the width direction W of the electrode 200 in the flat state. The width of the support member 100 can be 2mm-4mm, for example 3mm, and the width of the support member 100 is the dimension of the support member 100 along the length direction L of the electrode 200 in the flat state. The thickness of the support member 100 can be 0.1-0.3mm, for example 0.2mm, and the thickness of the support member 100 is the dimension of the support member 100 along the thickness direction of the electrode 200.

[0093] Specifically, when the support 100 is a phase change material structure 110, the steps for preparing the support 100 may include: S311: preparing a phase change material. S312: melting the solid phase change material into a liquid state at a temperature higher than the melting point of the phase change material, and forming a first intermediate structure with a first predetermined thickness by extrusion; or, cutting the solid phase change material into a first intermediate structure with a first predetermined thickness. S313: pressing the first intermediate structure into a second intermediate structure with a second predetermined thickness by rolling, the second predetermined thickness being less than the first predetermined thickness. S314: cutting the second intermediate structure into a structure with a length of a first predetermined length, a width of a first predetermined width, and a shape of a first predetermined shape to form the phase change material structure 110. Specifically, the first predetermined length may be greater than, equal to, or less than the width of the electrode 200. The first predetermined width and the second predetermined thickness can be reasonably designed according to the gas production capacity of the battery. The first predetermined shape may be an arc shape, a straight line shape, a wavy shape, etc., and can be set as needed, without being uniquely limited here.

[0094] For example, fully refined paraffin wax 62# with a phase change temperature T3 of 62℃-64℃ is selected as the phase change material. The fully refined paraffin wax 62# is melted into a liquid state at 70℃ and extruded to form a first intermediate structure in the shape of a strip with a first predetermined thickness of 300um-500um. This first intermediate structure is then rolled to form a second intermediate structure in the shape of a sheet with a second predetermined thickness of 150um. Finally, the second intermediate structure is cut to form a phase change material structure 110 with a first predetermined length x a first predetermined width x a second predetermined thickness of (width of electrode 200 + 1um) x 3mm x 150um. Using the above-mentioned phase change material structure 110 as the support member 100, when the internal temperature of the battery exceeds the minimum value of the phase change temperature T3, i.e., exceeds 62℃, the paraffin strip begins to melt. After the paraffin strip is completely melted, a discharge channel with a cross-sectional size of approximately 3mm x 140um can be formed inside the core 10.

[0095] Specifically, when the support 100 is a shape memory alloy structure 120, the steps for preparing the support 100 may include: S321: preparing a sheet-like shape memory alloy material. S322: cutting the shape memory alloy material into a structure with a length of a second predetermined length, a width of a second predetermined width, a thickness of a third predetermined thickness, and a shape of a second predetermined shape at a temperature lower than the deformation temperature T4 of the shape memory alloy material, to produce the shape memory alloy structure. Specifically, the second predetermined length may be greater than, equal to, or less than the width of the electrode 200. The second predetermined width and the third predetermined thickness can be reasonably designed according to the gas production capacity of the battery. The second predetermined shape can also be an arc shape, a straight strip shape, a wavy strip shape, etc., and can be set as needed, without being uniquely limited here.

[0096] For example, a nickel-titanium shape memory alloy material with a nickel content of approximately 52%-60%, in sheet form at room temperature, a deformation temperature T4 of 60℃-70℃, and a cross-sectional size of 3mm x 150um is prepared. This nickel-titanium shape memory alloy material is then cut into sheet-like nickel-titanium shape memory alloy strips with a second predetermined length x a second predetermined width x a third predetermined thickness of (electrode 200 width + 1um) x 3mm x 150um. Using these nickel-titanium shape memory alloy strips as support members 100, when the internal temperature of the battery exceeds the minimum deformation temperature T4 (i.e., exceeds 60℃), the nickel-titanium shape memory alloy strips gradually deform. The high-temperature phase of the nickel-titanium shape memory alloy strips can be rationally designed so that after deformation, the strips expand the separator 300 and electrode 200 adjacent to them, forming a discharge channel with a cross-sectional size of approximately 3mm x 150um inside the core 10.

[0097] S4: Winding, the two electrodes 200 and the two diaphragms 300 are alternately stacked and arranged, and the two diaphragms 300 and the two electrodes 200 are wound from the starting end to the tail end. When the winding reaches the predetermined position, the support member 100 is clamped between an adjacent electrode 200 and a diaphragm 300, so that the support member 100 is arranged along one side of the width direction of the electrode 200 to the other side of the width direction of the electrode 200, and at least one end of the support member 100 extends to the edge of the width direction of the electrode 200.

[0098] The manufacturing method of the core 10 provided in this embodiment allows for automated operation and simple operation when the electrode 200 and diaphragm 300 are wound to a predetermined position on the electrode 200 during the winding process. The support member 100 is clamped between an adjacent diaphragm 300 and an electrode 200, and the winding of the electrode 200 and diaphragm 300 continues.

[0099] This application also provides a method for manufacturing a battery, which includes the following steps:

[0100] S101: Prepare positive current collector 211, negative current collector 221, positive electrode material 212, negative electrode material 222, separator 300, electrolyte, shell and phase change material.

[0101] S102: Prepare the bipolar plate 200 by using a positive current collector 211, a negative current collector 221, a positive electrode material 212, and a negative electrode material 222.

[0102] S103: Prepare support 100 using phase change material.

[0103] S104: Winding, the two electrode sheets 200 and the two diaphragms 300 are alternately stacked and arranged, and the two diaphragms 300 and the two electrode sheets 200 are wound from the starting end to the tail end. When winding to a predetermined position, the support member 100 is clamped between an adjacent electrode sheet 200 and a diaphragm 300, so that the support member 100 is arranged along one side of the width direction of the electrode sheet 200 to the other side of the width direction of the electrode sheet 200, and at least one end of the support member 100 extends to the edge of the width direction of the electrode sheet 200 to form the core 10.

[0104] S105: Electrolyte injection and wetting: The core 10 is installed in the receiving cavity, and electrolyte is injected into the receiving cavity to wet the core 10, so as to make a semi-finished battery.

[0105] S106: Sealing, sealing the semi-finished battery to make it into a battery.

[0106] S107: Formation, the first charge and discharge cycle of the battery.

[0107] S108: Capacity testing, the battery is charged and discharged sequentially using 0.2C, 0.5C, and 1.0C. When the support member 100 is made of a paraffin strip with a first predetermined length x first predetermined width x second predetermined thickness of (width of electrode 200 + 1um) x 3mm x 150um, the final thickness of the support member 100 can be stabilized between approximately 145um and 150um.

[0108] The battery manufacturing method provided in this embodiment involves manufacturing the core 10 according to the above-described method for manufacturing the core 10, assembling the core 10 into the casing, and performing liquid injection, sealing, formation, and capacity testing processes to manufacture a battery with pressure relief function.

[0109] Furthermore, since paraffin wax is relatively soft and has a certain degree of elasticity, stress exists inside the core 10 during the charging and discharging process, which will cause the paraffin wax to deform. During the capacity division process, a small rate is used for charging and discharging first, and then a large rate is used for charging and discharging. This allows the paraffin wax strip to deform slowly, so that the deformation is not too sudden and drastic, thus improving consistency.

[0110] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A winding core for use in a battery, characterized in that, The core includes a support member, two electrodes, and two separators. The two electrodes and two separators are alternately stacked and wound together. The two electrodes are used to electrically connect the positive electrode tab and the negative electrode tab, respectively. The support member is sandwiched between an adjacent electrode and a separator, and the support member is arranged along one side of the width direction of the electrode to the other side of the width direction of the electrode. At least one end of the support member extends to the edge of the width direction of the electrode. The support member includes a phase change material structure and / or a shape memory alloy structure, which is used to undergo phase change and / or deformation after the battery temperature rises to a predetermined temperature range to form a pressure relief channel communicating with the outside of the core between the electrode and the separator adjacent to the support member. The thickness of the support member is 0.1-0.3 mm.

2. The winding core according to claim 1, characterized in that, The phase change material structure is a paraffin strip with a melting point of 62℃-64℃; the shape memory alloy structure is a nickel-titanium shape memory alloy strip with a deformation temperature of 60℃-70℃.

3. The winding core according to claim 1, characterized in that, The support includes a shape memory alloy structure. When the temperature is below the deformation temperature, the shape memory alloy structure is a strip structure. When the temperature is above the deformation temperature, at least one side of the shape memory alloy structure in the width direction bends toward the electrode adjacent to the shape memory alloy or toward the diaphragm adjacent to the shape memory alloy.

4. The winding core according to claim 1, characterized in that, The number of the support members is multiple, and the multiple support members are arranged at intervals along the length direction of the electrode; some of the multiple support members are the phase change material structure, and the other part of the multiple support members are the shape memory alloy structure. The shape memory alloy structure has a two-way shape memory effect, and the minimum deformation temperature of the shape memory alloy structure is lower than the minimum melting point of the phase change material structure.

5. The winding core according to any one of claims 1-4, characterized in that, The support extends in a straight line or a curve; the area of ​​the cross-section of the support remains constant along the length direction of the support, changes unidirectionally, or decreases first and then increases; the cross-section of the support is any one of triangle, rectangle, trapezoid, semicircle, or semi-ellipse; the support is arranged between an adjacent electrode and a diaphragm along the width direction of the electrode or the support is arranged obliquely between an adjacent electrode and a diaphragm relative to the width direction of the electrode.

6. A method for manufacturing a winding core, used to manufacture the winding core according to any one of claims 1-5, characterized in that, The method for manufacturing the core includes the following steps: Prepare positive current collector, negative current collector, positive electrode material, negative electrode material and separator; prepare phase change material and / or shape memory alloy material. Two electrodes are prepared using the positive current collector, the negative current collector, the positive electrode material, and the negative electrode material. The support component is prepared using a phase change material and / or a shape memory alloy material; The two electrodes and two diaphragms are alternately stacked and arranged, and the two alternately stacked diaphragms and two electrodes are wound from the starting end to the tail end. When the winding reaches a predetermined position, the support member is clamped between an adjacent electrode and a diaphragm, such that the support member is arranged along one side of the width direction of the electrode to the other side of the width direction of the electrode, and at least one end of the support member extends to the edge of the width direction of the electrode.

7. The method for manufacturing a winding core according to claim 6, characterized in that, The steps for preparing the two electrodes include: The positive electrode material is applied intermittently or continuously to the surface of the positive electrode current collector, and the negative electrode material is applied intermittently or continuously to the surface of the negative electrode current collector; The positive current collector coated with the positive electrode material and the negative current collector coated with the negative electrode material are rolled and slit.

8. The method for manufacturing a winding core according to claim 6, characterized in that, When the support is a phase change material structure, the steps for manufacturing the support include: Prepare phase change materials; The solid phase change material is melted into a liquid state at a temperature higher than the melting point of the phase change material, and a first intermediate structure with a first predetermined thickness is formed by extrusion; or the solid phase change material is cut into a first intermediate structure with a first predetermined thickness. The first intermediate structure is pressed into a second intermediate structure with a second predetermined thickness by a roll forming method, wherein the second predetermined thickness is less than the first predetermined thickness; The second intermediate structure is cut into a structure with a length of a first predetermined length, a width of a first predetermined width, and a shape of a first predetermined shape, in order to produce the phase change material structure; When the support is a shape memory alloy structure, the steps for manufacturing the support include: Prepare sheet-like shape memory alloy materials; The shape memory alloy material is cut into a structure with a length of a second predetermined length, a width of a second predetermined width, a thickness of a third predetermined thickness, and a shape of a second predetermined shape at a temperature below the deformation temperature of the shape memory alloy material, in order to manufacture the shape memory alloy structure.

9. A battery, characterized in that, The battery includes a casing and a winding core as described in any one of claims 1-5. The casing has a housing and a pressure relief valve. The housing has a receiving cavity and a through hole communicating with the receiving cavity. The receiving cavity is used to install the winding core, and the through hole is used to install the pressure relief valve.

10. A method for manufacturing a battery, used to manufacture the battery of claim 9, characterized in that, The method for manufacturing the battery includes the following steps: Prepare positive current collector, negative current collector, positive electrode material, negative electrode material, separator, electrolyte, shell and phase change material; Two electrodes are prepared using the positive current collector, the negative current collector, the positive electrode material, and the negative electrode material. The support component is prepared using a phase change material. The winding process involves alternately stacking two electrode sheets and two diaphragms, and winding the alternately stacked diaphragms and two electrode sheets from the starting end to the tail end. When the winding reaches a predetermined position, the support member is filled between an adjacent diaphragm and an electrode sheet, such that the support member is arranged along one side of the width direction of the electrode sheet to the other side of the width direction of the electrode sheet, and at least one end of the support member extends to the edge of the width direction of the electrode sheet to form the core. Electrolyte injection is performed by installing the winding core into the accommodating cavity and injecting the electrolyte into the accommodating cavity to wet the winding core, thereby producing a semi-finished battery. Sealing: The semi-finished battery is sealed to form a battery; The battery is then subjected to its first charge and discharge cycle after formation. The battery was then charged and discharged sequentially at 0.2C, 0.5C, and 1.0C.

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