Battery, method for manufacturing battery roll core, and audio playback device

Abstract

The application relates to battery technology and provides a battery and an audio playing device. The battery comprises a positive plate and a negative plate, the positive plate and the negative plate are arranged in a winding mode, the positive plate comprises a first part and a second part arranged in a symmetrical mode, the negative plate comprises a third part and a fourth part arranged in a symmetrical mode, the first part generates a first magnetic field, the second part generates a second magnetic field, the third part generates a third magnetic field, and the fourth part generates a fourth magnetic field, wherein the first magnetic field and the second magnetic field have opposite polarities, and the third magnetic field and the fourth magnetic field have opposite polarities. The two magnetic fields with opposite polarities generated by the positive plate can be offset to each other, and the two magnetic fields with opposite polarities generated by the negative plate can be offset to each other. Therefore, under the premise of not increasing the cost and structure, the simple arrangement mode makes the magnetic field coupling inhibition effect of the whole battery better than the magnetic field offset effect of a conventional battery.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery, a method for preparing a battery coil, and an audio playback device. Background Art

[0002] In the prior art, audio playback devices with batteries and speakers, such as wireless headphones and wireless speakers, have a certain amount of magnetic field interference from the batteries on the speakers, resulting in noise. To address this defect, there are currently several solutions, including adding simple shielding measures between the battery and the speakers, adding filtering components to the circuit between the battery and the speakers, and physically separating the battery and the speakers (for example, the battery and the speakers are not coaxial or at a certain angle).

[0003] However, until the root cause of battery interference with speakers is identified and effective countermeasures are implemented to fundamentally address the magnetic field interference, adding shielding measures and filtering components will increase costs, while changing the stacking structure will increase the product's size and complexity. Furthermore, proposals have been proposed to reduce the strength of the battery's external magnetic field, but these also have drawbacks: the outer ring of the wound battery core has an asymmetric structure due to the different lengths of the positive and negative electrodes. When the current suddenly changes, the magnetic fields generated by the positive and negative electrodes cannot cancel each other out, resulting in the battery's high magnetic field radiation. Summary of the Invention

[0004] The purpose of this application is to provide a battery, a method for preparing a battery core, and an audio playback device, aiming to solve the problem that batteries using traditional winding methods have complex structures and have large magnetic field radiation to the outside.

[0005] A first aspect of an embodiment of the present application provides a battery, comprising a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are wound, the positive electrode sheet comprises a symmetrically arranged first part and a second part, and the negative electrode sheet comprises a symmetrically arranged third part and a fourth part; during charging and discharging, the currents passing through the first part and the second part are equal in magnitude and opposite in direction, and the currents passing through the third part and the fourth part are equal in magnitude and opposite in direction; and the first part generates a first magnetic field, the second part generates a second magnetic field, the third part generates a third magnetic field, and the fourth part generates a fourth magnetic field, wherein the first magnetic field and the second magnetic field have opposite polarities, and the third magnetic field and the fourth magnetic field have opposite polarities.

[0006] In one embodiment, the first part and the second part are two sections of electrode sheets with aligned tail ends formed by folding the unfolded positive electrode sheet in half of equal length, and the third part and the fourth part are two sections of electrode sheets with aligned tail ends formed by folding the unfolded negative electrode sheet in half of equal length. The first part is inserted between the third part and the fourth part, and the tail end of the first part is close to the folded part of the negative electrode sheet. The third part is inserted between the first part and the second part, and the tail end of the third part is close to the folded part of the positive electrode sheet.

[0007] In one embodiment, the first portion and the second portion have the same length and width, and the third portion and the fourth portion have the same length and width.

[0008] In one embodiment, the folded portion of the negative electrode sheet and the folded portion of the positive electrode sheet are not coated with active material.

[0009] In one embodiment, the length of the third portion is greater than the length of the first portion, and the width of the third portion is greater than the width of the first portion.

[0010] In one embodiment, the winding configuration is to start from the folded part of the negative electrode sheet, the tail end of the first part and one end of the tail end of the second part, or to start from one of the folded part of the positive electrode sheet, the tail end of the third part and one end of the tail end of the fourth part.

[0011] In one embodiment, it further includes a positive electrode tab and a negative electrode tab, wherein the positive electrode tab is arranged at the tail end of the first part or the second part, and the negative electrode tab is arranged at the tail end of the third part or the fourth part.

[0012] A second aspect of the embodiments of the present application provides a method for preparing a battery roll core.

[0013] Folding the positive electrode sheet in half to form a first portion and a second portion that are symmetrically arranged;

[0014] Folding the negative electrode sheet in half to form a third portion and a fourth portion that are symmetrically arranged;

[0015] Insert the first portion between the third portion and the fourth portion with the tail end of the first portion close to the folded portion of the negative electrode sheet, and insert the third portion between the first portion and the second portion with the tail end of the third portion close to the folded portion of the positive electrode sheet;

[0016] Winding the electrode from the folded portion of the negative electrode sheet, one end of the tail end of the first portion, and one end of the tail end of the second portion as a starting point, or from the folded portion of the positive electrode sheet, one end of the tail end of the third portion, and one end of the tail end of the fourth portion as a starting point;

[0017] Wherein, the positive electrode sheet and the negative electrode sheet are separated by a separator.

[0018] In one embodiment, the first portion and the second portion have the same length and width, and the third portion and the fourth portion have the same length and width.

[0019] A third aspect of the embodiments of the present application provides an audio playback device, including a speaker and the above-mentioned battery.

[0020] The positive electrode sheet of the above-mentioned battery includes a symmetrically arranged first part and a second part, and the negative electrode sheet includes a symmetrically arranged third part and a fourth part. After being wound, during charging and discharging, the magnetic fields generated by the symmetrically arranged first part and the second part have opposite polarities and can offset each other. The magnetic fields generated by the symmetrically arranged third part and the fourth part have opposite polarities and can also offset each other. It can be seen that without increasing the cost and structure, the overall magnetic field coupling suppression effect of the battery is better than the magnetic field offset effect of conventional batteries through a simple setting method.

[0021] In addition, when the above-mentioned battery is applied to an audio playback device, the external magnetic field inside the battery is well suppressed, which can reduce the strength of the external magnetic field of the battery, thereby reducing the interference of the battery on the speaker and improving the performance of the audio playback device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram showing the structural comparison of the positive and negative electrodes of the battery core;

[0023] Figure 2 A schematic diagram of the winding structure of a battery provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of the structure of the positive and negative electrode sheets of the battery provided in Example 1 of the present application folded in half;

[0025] Figure 4 A schematic structural diagram of the positive and negative electrodes of the battery provided in Example 1 of the present application;

[0026] Figure 5 A schematic diagram of the structure of the positive and negative electrodes of the battery provided in Example 2 of the present application folded in half;

[0027] Figure 6 A schematic structural diagram of the positive and negative electrodes of the battery provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0031] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0032] See also Figure 1 Generally, a battery includes a positive electrode sheet, a negative electrode sheet, and a separator (not shown). The positive electrode sheet includes a positive electrode current collector and a positive electrode active material coated on the positive electrode current collector. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material coated on the negative electrode current collector. Usually, the positive electrode current collector is made of aluminum foil, and the negative electrode current collector is made of copper foil. After the positive electrode sheet, separator, and negative electrode sheet are stacked in this order, they are wound to form a core, and the outermost layer of the core is finished with copper foil or aluminum foil. Because the overhang safety design of the positive and negative electrode sheets needs to be considered when designing the battery, that is, there is a difference between the width W1 of the positive electrode sheet and the width W2 of the negative electrode sheet, and there is a difference between the length L1 of the positive electrode sheet and the length L2 of the negative electrode sheet, so the sizes of the positive and negative electrode sheets are not exactly the same.

[0033] During the charging and discharging process, the magnetic fields generated by the currents in the positive and negative electrodes differ in direction, depending on the direction of the current. In a single winding core, if the currents in the positive and negative electrodes are in the same direction, the magnetic fields generated are in the same direction, and the magnetic fields are coupled and superimposed. If the currents in the positive and negative electrodes are in opposite directions, the magnetic fields generated are in different directions, and the two can cancel each other out. However, due to the different widths and lengths of the positive and negative electrodes, the magnetic fields generated by the electrodes in the non-overlapping areas of the positive and negative electrodes in a single winding core cannot be canceled out, and a magnetic field still exists. In other words, during the charging and discharging process, the magnetic fields of a single winding core cannot be completely canceled out, and there is always external magnetic field interference. To this end, in the inventive concept proposed in this application, the positive and negative electrodes are folded in half and partially nested together to form a double-layer electrode winding structure. Two opposite current directions exist in the same electrode, and the magnetic fields generated by the same electrode can be completely canceled out. Therefore, the external magnetic field of the entire battery can also be well suppressed, and will not interfere with external devices.

[0034] Specifically, see Figure 2 The battery provided in the embodiment of the present application includes a positive electrode sheet 11 and a negative electrode sheet 12, which are wound together. The positive electrode sheet 11 includes a first portion 112 and a second portion 114 that are symmetrically arranged, and the negative electrode sheet 12 includes a third portion 122 and a fourth portion 124 that are symmetrically arranged. During charging and discharging, the currents passing through the first portion 112 and the second portion 114 are equal in magnitude and opposite in direction, and the currents passing through the third portion 122 and the fourth portion 124 are equal in magnitude and opposite in direction. The first portion 112 generates a first magnetic field, the second portion 114 generates a second magnetic field, the third portion 122 generates a third magnetic field, and the fourth portion 124 generates a fourth magnetic field. "Symmetrically arranged" means that the two portions are close to each other and similar in shape. In addition, since the positive electrode sheet 11 and the negative electrode sheet 12 are separated by a diaphragm, the two symmetrically arranged portions are not necessarily directly adjacent.

[0035] During charging and discharging, the first and second magnetic fields have opposite polarities. The two magnetic fields of opposite polarity generated by the positive electrode 11 can cancel each other out. The third and fourth magnetic fields have opposite polarities, and the two magnetic fields of opposite polarity generated by the negative electrode 12 can also cancel each other out. In this way, each electrode offsets its own magnetic field with a symmetrical structure, and the magnetic field generated by the entire battery is self-suppressed. In this embodiment, even if the length and width of the negative electrode 12 are greater than those of the positive electrode 11, the magnetic field generated by the battery can still significantly cancel each other out.

[0036] See also Figure 3In one embodiment, the first portion 112 and the second portion 114 are formed by folding the unfolded positive electrode sheet 11 in half, with the ends A1 and D1 aligned. The third portion 122 and the fourth portion 124 are formed by folding the unfolded negative electrode sheet 12 in half, with the ends A and D aligned. The first portion 112 is inserted between the third portion 122 and the fourth portion 124, with the end D1 of the first portion 112 close to the folded portion 123 of the negative electrode sheet 12. The third portion 122 is inserted between the first portion 112 and the second portion 114, with the end D of the third portion 122 close to the folded portion 113 of the positive electrode sheet 11. It should be noted that the positive electrode sheet 11 and the negative electrode sheet 12 are separated by a separator. Figure 2 and Figure 3 In order to clearly indicate the positional relationship between the positive and negative electrode sheets, the separator is not drawn; "close" means that the tail end D1 of the first portion 112 is close to the folded portion 123 of the negative electrode sheet 12, but not in direct contact. The tail end D1 of the first portion 112 is separated from the folded portion 123 of the negative electrode sheet 12 by the separator, and the tail end D1 of the first portion 112 is in contact with the separator; similarly, the tail end D of the third portion 122 is close to the folded portion 113 of the positive electrode sheet 11, but not in direct contact. The tail end D of the third portion 122 is separated from the folded portion 113 of the positive electrode sheet 11 by the separator, and the tail end D of the third portion 122 is in contact with the separator. In this embodiment, the positive electrode sheet 11 is symmetrically bent to form the first portion 112 and the second portion 114, and the negative electrode sheet 12 is symmetrically bent to form the third portion 122 and the fourth portion 124. Specifically, please refer to Figure 3 and Figure 4 The positive electrode sheet 11 includes a positive electrode current collector and a positive electrode active material 21 coated on the positive electrode current collector, and the negative electrode sheet 12 includes a negative electrode current collector and a negative electrode active material 22 coated on the negative electrode current collector. The positive electrode sheet 11 and the negative electrode sheet 12 are folded in half to form a first part 112, a second part 114, a third part 122 and a fourth part 124.

[0037] In this embodiment, the winding is set to start from the folded bend 123 of the negative electrode sheet 12, the tail end D1 of the first part 112 and the tail end A1 of the second part 114, or the winding is set to start from the folded bend 113 of the positive electrode sheet 11, the tail end D of the third part 122 and the tail end A of the fourth part 124. Figure 3 In the illustrated example, winding is performed starting from the fold 123 of the negative electrode sheet 12, the tail end D1 of the first portion 112, and the tail end A1 of the second portion 114. After winding is completed, the other end is fixedly connected using an insulating member 15, which is a double-sided tape or ordinary adhesive tape. In other embodiments, winding can be performed starting from the other end.

[0038] Specifically, when winding, the positive electrode sheet 11 and the negative electrode sheet 12 are folded in half, and one end of the positive electrode sheet 11 (i.e., the tail end D1 of the first portion 112) is inserted into the folded position of the negative electrode sheet 12 (i.e., Figure 3 As shown), one end of the positive electrode sheet 11 (i.e., the tail end D1 of the first part 112) and the other end (i.e., the tail end A1 of the second part 114) are aligned and then wound; after the electrode sheet is folded in half, the current direction of the positive electrode sheet 11 and the negative electrode sheet 12 changes. Figure 3 As shown, the currents in segments A1B1 and C1D1 of the positive electrode sheet 11 flow in opposite directions, generating magnetic fields in opposite directions that can cancel each other out. The currents in segments AB and CD of the negative electrode sheet 12 flow in opposite directions, generating magnetic fields in opposite directions that can cancel each other out. Therefore, the first portion 112 and the second portion 114 have equal lengths and widths, and the third portion 122 and the fourth portion 124 have equal lengths and widths. During charging and discharging, the magnetic fields generated by the positive electrode sheet 11 and the negative electrode sheet 12 can cancel each other out, effectively avoiding the problem of external magnetic field interference caused by the different lengths of the positive and negative electrode sheets 11 and 12 in conventional batteries.

[0039] See also Figure 4 In some embodiments, the negative electrode current collector of the negative electrode sheet 12 is not coated with active material at the fold 123, and the positive electrode current collector of the positive electrode sheet 11 is not coated with active material at the fold 113. The positive and negative electrode current collectors at other locations are coated with the corresponding positive and negative electrode active material 21 and 22. In this way, a blank area for coating is left between the folds of the positive and negative electrode sheets 11 and 12 of the battery. This is primarily to prevent breakage or powdering (i.e., shedding of active material) after the fold, which could affect the battery's electrical and safety performance.

[0040] See also Figure 5 In another embodiment, the battery further includes a first curved connecting conductor 115 and a second curved connecting conductor 125. The first end C1 of the first portion 112 and the first end B1 of the second portion 114 are fixedly connected via the first curved connecting conductor 115. The first end C of the third portion 122 and the first end B of the fourth portion 124 are fixedly connected via the second curved connecting conductor 125. The first portion 112 is inserted between the third portion 122 and the fourth portion 124, and the tail end D1 of the first portion 112 is close to the second curved connecting conductor 125. The third portion 122 is inserted between the first portion 112 and the second portion 114, and the tail end D of the third portion 122 is close to the first curved connecting conductor 115. It should be noted that the positive electrode sheet 11 and the negative electrode sheet 12 are separated by a diaphragm. Figure 5 In order to clearly show the positional relationship between the positive and negative electrodes, the separator is not drawn.

[0041] In this embodiment, the first and second portions 112, 114, and the third and fourth portions 122, 124 are not integrally formed. The first and second portions 112, 114 are of equal length and width, while the third and fourth portions 122, 124 are of equal length and width. During charging and discharging, the magnetic field generated by the positive electrode sheet can be offset by itself, and the magnetic field generated by the negative electrode sheet can also be offset by itself, effectively avoiding the external magnetic field interference caused by the different lengths of the positive and negative electrode sheets in conventional batteries. Each portion is independently manufactured and then connected by a first curved connecting conductor 115 and a second curved connecting conductor 125. Therefore, the entire electrode sheet can be coated with active material. Of course, the first and second curved connecting conductors 115, 125 do not need to be coated with active material.

[0042] In this embodiment, the winding setting is to start from the second curved connecting conductor 125, the tail end D1 of the first part 112 and the tail end A1 of the second part 114, or to start from the first curved connecting conductor 115, the tail end D of the third part 122 and the tail end A of the fourth part 124. Figure 5 In the example shown, the winding starts from one end of the second meandering connecting conductor 125 , the tail end D1 of the first portion 112 and the tail end A1 of the second portion 114 . In other embodiments, the winding can start from the other end.

[0043] Specifically, during winding, the first portion 112 and the second portion 114 have the same length and width, and the third portion 122 and the fourth portion 124 have the same length and width. After they are independently manufactured, the first portion 112 and the second portion 114 are connected together using the first curved connecting conductor 115 to form the positive electrode sheet 11, and the third portion 122 and the fourth portion 124 are connected together using the second curved connecting conductor 125 to form the negative electrode sheet 12. One end of the positive electrode sheet 11 is inserted into the position of the second curved connecting conductor 125 (such as Figure 5 As shown), one end of the positive electrode sheet 11 (i.e., the tail end D1 of the first part 112) and the other end (i.e., the tail end A1 of the second part 114) are aligned and then wound; the two parts of each electrode sheet are symmetrical, so the relative direction of the positive (or negative) current changes, as shown. Figure 5 As shown, the current directions of the A1B1 segment and the C1D1 segment of the positive electrode sheet 11 are opposite, and the magnetic fields generated are opposite, which can cancel each other out; the currents of the AB segment and the CD segment of the negative electrode sheet 12 are opposite, and the magnetic fields generated are also opposite, which can cancel each other out.

[0044] Furthermore, the length of the third portion 122 is greater than that of the first portion 112, and the width of the third portion 122 is greater than that of the first portion 112, to prevent lithium deposition during charging. It can be understood that a positive electrode sheet 11 coated with a positive electrode active material 21 must have a corresponding negative electrode sheet 12 coated with a negative electrode active material 22. Otherwise, lithium deposition during charging could pose a safety hazard. However, a negative electrode sheet 12 coated with a negative electrode active material 22 does not necessarily have to have a corresponding positive electrode sheet 11 coated with a positive electrode active material 21. The outermost portion of the winding core could be the positive electrode sheet 11. In this case, the outermost portion of the positive electrode sheet 11 would not be coated with the positive electrode active material 21, to prevent lithium deposition during charging, which could pose a safety hazard (because there is no corresponding negative electrode active material 22). Alternatively, the outermost portion of the winding core could be the negative electrode sheet 12, which could be coated with or not coated with the negative electrode active material 22.

[0045] See also Figures 2 to 5 The battery also includes a positive electrode tab 13 and a negative electrode tab 14. The positive electrode tab 13 is disposed at the end of the second portion 114, and the negative electrode tab 14 is disposed at the end of the fourth portion 124. Alternatively, the positive electrode tab 13 is disposed at the end of the first portion 112, and the negative electrode tab 14 is disposed at the end of the third portion 122. The positive electrode tab 13 is disposed at the end of the first portion 112 or the second portion 114 to ensure that the current directions of the first portion 112 and the second portion 114 are opposite during charging and discharging; the negative electrode tab 14 is disposed at the end of the third portion 122 or the fourth portion 124 to ensure that the current directions of the third portion 112 and the fourth portion 124 are opposite during charging and discharging. Generally, the positive electrode tab 13 is an aluminum tab, and the negative electrode tab 14 is a nickel tab.

[0046] See also Figure 6 The battery further includes a separator 16, which is disposed between the positive electrode sheet 11 and the negative electrode sheet 12 to prevent the positive electrode sheet 11 and the negative electrode sheet 12 from directly contacting each other and causing a short circuit.

[0047] It can be seen from the above two embodiments that the battery of the present application forms a double-layer electrode sheet winding structure after the positive electrode sheet and the negative electrode sheet are folded in half. After the winding is completed, the tail is closed and protective tape is affixed. There are two opposite current directions in the same electrode sheet, and the magnetic fields generated can offset each other, which can effectively reduce the magnetic field radiation of the battery.

[0048] The wound-type battery structure of the present application involves folding one electrode sheet in half, inserting another electrode sheet into the folded position, ensuring that the positive and negative electrode sheets align at their ends, and then winding the electrode sheet to form a novel battery structure that effectively reduces the battery's external magnetic field. In some cases, the folded portion of the electrode sheet is not coated with active material to prevent breakage and powder loss after the fold.

[0049] A second aspect of the present application provides a method for preparing a battery core, which can be used to manufacture the above-mentioned battery, and specifically comprises the following steps:

[0050] Step 1: Fold the positive electrode sheet in half to form a first part and a second part that are symmetrically arranged;

[0051] Step 2: Fold the negative electrode sheet in half to form a third part and a fourth part that are symmetrically arranged;

[0052] Step 3: inserting the first portion between the third portion and the fourth portion with the tail end of the first portion close to the folded portion of the negative electrode sheet, and inserting the third portion between the first portion and the second portion with the tail end of the third portion close to the folded portion of the positive electrode sheet;

[0053] Step 4: Winding the negative electrode sheet from the folded portion, the tail end of the first portion, and one end of the tail end of the second portion as a starting point, or winding the positive electrode sheet from the folded portion, the tail end of the third portion, and one end of the tail end of the fourth portion as a starting point;

[0054] Wherein, the positive electrode sheet and the negative electrode sheet are separated by a separator.

[0055] It should be understood that the size of the step numbers in the above steps 1 and 2 does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0056] In one embodiment, the first portion and the second portion have the same length and width, and the third portion and the fourth portion have the same length and width.

[0057] The specific implementation of the method for preparing the above-mentioned battery roll core can refer to the specific implementation of the battery provided in the first aspect of this application, and will not be repeated here.

[0058] The third aspect of the present application further provides an audio playback device comprising a speaker and the aforementioned battery. The technical solution of the present application improves the winding core, effectively reducing the magnetic field generated by the battery during charging and discharging, without adding external components and without affecting the structure of the audio playback device.

[0059] In addition, the technical solution of this application proposes a solution to the background noise caused by the magnetic interference of the battery on the speaker in the audio playback device from a fundamental principle, which effectively reduces the external magnetic field of the battery, has the advantages of low cost, no increase in size and space, and high efficiency, and solves the technical problem of interference background noise that the true wireless Bluetooth headset industry has been facing and has not been solved for a long time.

[0060] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A battery, characterized in that: The battery comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are wound and arranged, the positive electrode sheet comprises a first portion and a second portion which are symmetrically arranged, and the negative electrode sheet comprises a third portion and a fourth portion which are symmetrically arranged; during charging and discharging, the currents passing through the first portion and the second portion are equal in magnitude and opposite in direction, and the currents passing through the third portion and the fourth portion are equal in magnitude and opposite in direction; and the first portion generates a first magnetic field, the second portion generates a second magnetic field, the third portion generates a third magnetic field, and the fourth portion generates a fourth magnetic field, wherein the first magnetic field and the second magnetic field have opposite polarities, and the third magnetic field and the fourth magnetic field have opposite polarities; The first portion and the second portion are two electrode sheets formed by folding the unfolded positive electrode sheet in half of equal length, with their tail ends aligned; the third portion and the fourth portion are two electrode sheets formed by folding the unfolded negative electrode sheet in half of equal length, with their tail ends aligned; the first portion is inserted between the third portion and the fourth portion, with the tail end of the first portion close to the folded portion of the negative electrode sheet; the third portion is inserted between the first portion and the second portion, with the tail end of the third portion close to the folded portion of the positive electrode sheet; It also includes a positive electrode tab and a negative electrode tab. The positive electrode tab is arranged at the tail end of the first part or the second part, and the negative electrode tab is arranged at the tail end of the third part or the fourth part.

2. The battery according to claim 1, wherein The folded portion of the negative electrode sheet and the folded portion of the positive electrode sheet are not coated with active material.

3. The battery according to claim 1, wherein The winding configuration is to start from the folded part of the negative electrode sheet, one end of the tail end of the first part and one end of the tail end of the second part, or to start from the folded part of the positive electrode sheet, one end of the tail end of the third part and one end of the tail end of the fourth part.

4. The battery according to any one of claims 1 to 3, characterized in that The first portion and the second portion have the same length and width, and the third portion and the fourth portion have the same length and width.

5. The battery according to claim 4, wherein The length of the third portion is greater than that of the first portion, and the width of the third portion is greater than that of the first portion.

6. A method for preparing a battery core, characterized in that: include: Folding the positive electrode sheet in half to form a first portion and a second portion that are symmetrically arranged; Folding the negative electrode sheet in half to form a third portion and a fourth portion that are symmetrically arranged; Insert the first portion between the third portion and the fourth portion with the tail end of the first portion close to the folded portion of the negative electrode sheet, and insert the third portion between the first portion and the second portion with the tail end of the third portion close to the folded portion of the positive electrode sheet; Winding the electrode from the folded portion of the negative electrode sheet, one end of the tail end of the first portion, and one end of the tail end of the second portion as a starting point, or from the folded portion of the positive electrode sheet, one end of the tail end of the third portion, and one end of the tail end of the fourth portion as a starting point; The positive electrode tab is arranged at the tail end of the first part or the second part, and the negative electrode tab is arranged at the tail end of the third part or the fourth part; Wherein, the positive electrode sheet and the negative electrode sheet are separated by a separator.

7. The preparation method according to claim 6, wherein The first portion and the second portion have the same length and width, and the third portion and the fourth portion have the same length and width.

8. An audio playback device, comprising a speaker, characterized in that: Also includes the battery according to any one of claims 1 to 3 and 6.

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