Battery and audio playback device

Abstract

The application relates to battery technology, and provides a battery and an audio playing device. The battery comprises: a first winding core comprising a first positive plate and a first negative plate, the first winding core generating a first magnetic field in use; and a second winding core comprising a second positive plate and a second negative plate, the second winding core generating a second magnetic field in use; wherein the first winding core is arranged in the second winding core, the current flowing through the first positive plate is opposite to the current flowing through the second positive plate, and the current flowing through the first negative plate is opposite to the current flowing through the second negative plate, so that the first magnetic field and the second magnetic field at least partially overlap and have opposite polarities. Therefore, the first magnetic field and the second magnetic field can offset each other, so that the external magnetic field radiation of the battery is minimized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery and an audio playing device. BACKGROUND

[0002] In the prior art, an audio playing device with a battery and a loudspeaker, such as a wireless earphone, a wireless sound box and the like, has a certain magnetic field interference of the battery on the loudspeaker, and thus noise occurs. In order to solve this defect, currently, there are mainly several schemes of adding a simple shielding measure between the battery and the loudspeaker, adding a filtering component on a circuit before the battery and the loudspeaker, and physically separating the battery and the loudspeaker (for example, the battery and the loudspeaker are different in axis or at a certain angle).

[0003] However, before the root cause of the interference of the battery on the loudspeaker is found and an effective countermeasure is taken in principle to truly solve the magnetic field interference problem, the addition of the shielding measure and the filtering component will lead to an increase in cost, and the change in the structure stacking scheme will increase the space size of the product and make the structure more complex. In addition, a scheme of reducing the magnetic field strength of the battery to the outside is also proposed, but there are also deficiencies: the outer circle of the wound battery roll core has an asymmetric structure caused by different lengths of positive and negative electrode sheets, when the current suddenly changes, the magnetic fields generated by the currents on the positive and negative electrode sheets cannot be offset, and thus the battery has a large magnetic field radiation. SUMMARY

[0004] The application aims to provide a battery and an audio playing device, and aims to solve the problems of a battery adopting a traditional winding mode that has a complex structure and a large magnetic field radiation to the outside.

[0005] A first aspect of the application provides a battery, comprising:

[0006] a first roll core comprising a first positive electrode sheet and a first negative electrode sheet, the first roll core generating a first magnetic field when in use;

[0007] a second roll core comprising a second positive electrode sheet and a second negative electrode sheet, the second roll core generating a second magnetic field when in use; wherein the first roll core is arranged in the second roll core, and when in use, the current flowing through the first positive electrode sheet is opposite in direction to the current flowing through the second positive electrode sheet, and the current flowing through the first negative electrode sheet is opposite in direction to the current flowing through the second negative electrode sheet; and

[0008] a shell;

[0009] the first roll core and the second roll core are arranged in the shell, so that the first magnetic field and the second magnetic field at least partially overlap and have opposite polarities.

[0010] In one of the embodiments, the first jelly-roll and the second jelly-roll are arranged in series, the outer end of the first positive electrode tab is connected to the inner end of the second positive electrode tab, and the outer end of the first negative electrode tab is connected to the inner end of the second negative electrode tab.

[0011] In one of the embodiments, the positive electrode tab and the negative electrode tab are further included, and the positive electrode tab and the negative electrode tab are arranged at the outer end of the second positive electrode tab and the outer end of the second negative electrode tab, respectively.

[0012] In one of the embodiments, the first positive electrode tab and the second positive electrode tab are different electrode tabs, the first negative electrode tab and the second negative electrode tab are different electrode tabs, and the first jelly-roll and the second jelly-roll are arranged in series or in parallel.

[0013] In one of the embodiments, the winding directions of the first jelly-roll and the second jelly-roll are opposite.

[0014] In one of the embodiments, the surfaces of the positive electrode tab and the negative electrode tab, which are opposite to each other, include active material.

[0015] The surface of the positive electrode tab, which is opposite to the negative electrode tab, includes active material, and the surface of the negative electrode tab, which is opposite to the positive electrode tab, includes active material.

[0016] The surface of the positive electrode tab, which is not opposite to the negative electrode tab, does not include active material.

[0017] In one of the embodiments, the connection between the outer end of the first positive electrode tab and the inner end of the second positive electrode tab, and the connection between the outer end of the first negative electrode tab and the outer end of the second negative electrode tab form a double-folded bending part, and the inner and outer surfaces of the double-folded bending part do not include active material.

[0018] In one of the embodiments, the double-folded bending part is fixedly connected to the outer surface of the first jelly-roll through an insulating member.

[0019] In one of the embodiments, the inner positive electrode tab arranged at the outer end of the first positive electrode tab, the outer positive electrode tab arranged at the outer end of the second positive electrode tab, the inner negative electrode tab arranged at the outer end of the first negative electrode tab, and the outer negative electrode tab arranged at the outer end of the second negative electrode tab are further included, and the first connecting conductor and the second connecting conductor are further included, wherein:

[0020] The outer positive electrode tab and the inner negative electrode tab are electrically connected through the first connecting conductor, and the inner positive electrode tab and the outer negative electrode tab are electrically connected through the second connecting conductor; or

[0021] The inner positive electrode tab is electrically connected with the outer positive electrode tab through the first connecting conductor, and the outer negative electrode tab is electrically connected with the inner negative electrode tab through the second connecting conductor.

[0022] A second aspect of the embodiment of the application provides an audio playing device, comprising a loudspeaker and the battery.

[0023] The battery comprises two nested winding cores, and the electrode plates of the same polarity are opposite in current direction in the two winding cores, the magnetic field generated by the inner winding core is opposite to the magnetic field generated by the outer winding core, and the two magnetic fields offset each other, so that the magnetic field coupling suppression effect of the nested winding core structure is better than that of the parallel winding core structure, and the external magnetic field of the battery as a whole is suppressed without increasing the cost and structure.

[0024] In addition, when the battery is applied to the audio playing device, the external magnetic field of the battery can be reduced due to the mutual offset of the internal magnetic field of the battery, so that the interference of the battery on the loudspeaker can be reduced, and the performance of the audio playing device can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A structural comparison diagram of positive electrode plates and negative electrode plates of the battery;

[0026] Figure 2 A winding structure diagram of the battery provided in the embodiment of the application;

[0027] Figure 3A A first winding mode diagram of the battery provided in the embodiment of the application;

[0028] Figure 3B A second winding mode diagram of the battery provided in the embodiment of the application;

[0029] Figure 4 A structural comparison diagram of positive electrode plates and negative electrode plates of the battery provided in the embodiment of the application;

[0030] Figure 5 A winding structure diagram of the battery provided in the embodiment of the application;

[0031] Figure 6 A magnetic field direction diagram of the battery provided in the embodiment of the application. DETAILED DESCRIPTION

[0032] In order to make the technical problems, technical solutions and beneficial effects of the application clearer, the application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0033] It is to be noted that when an element is referred to as being "fixed" or "set" on another element, it can 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 can be directly connected to the other element or indirectly connected to the other element.

[0034] It is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like, indicate directions or positions based on the directions or positions shown in the drawings, and are used for convenience only in describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the application.

[0035] In addition, the terms "first", "second", "third", etc., are used only for descriptive purposes and cannot be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0036] Please refer to Figure 1 Generally, the battery includes a positive electrode sheet, a negative electrode sheet, and a separator (not shown in the figure), the positive electrode sheet includes a positive electrode current collector and a positive electrode active material coated on the positive electrode current collector, and the negative electrode sheet includes a negative electrode current collector and a negative electrode active material coated on the negative electrode current collector. Generally, the positive electrode current collector is an aluminum foil, and the negative electrode current collector is a copper foil. After the positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, a winding core is formed by winding, and the winding core is finished with a copper foil or an aluminum foil on the outermost layer. This is because the battery design needs to consider the overhang safety design of the positive electrode sheet and the negative electrode sheet, i.e., the width W1 of the positive electrode sheet and the width W2 of the negative electrode sheet are different, and the length L1 of the positive electrode sheet and the length L2 of the negative electrode sheet are different, so the sizes of the positive electrode sheet and the negative electrode sheet are not exactly the same.

[0037] During charging and discharging, the magnetic field directions generated by the current of the positive plate and the negative plate are different according to the direction difference of the current in the positive plate and the negative plate. In a single winding core, if the current directions in the positive plate and the negative plate are the same, the generated magnetic field directions are the same, and the magnetic fields are coupled and superimposed; if the current directions in the positive plate and the negative plate are opposite, the generated magnetic fields are in different directions, and the two can cancel each other out, but due to the difference in width and length of the positive plate and the negative plate, the magnetic field generated by the non-overlapping area of the positive plate and the negative plate in the single winding core cannot be canceled out, and the winding core still has a magnetic field. In addition, after the positive plate and the negative plate are wound, the current passing through the positive plate and the negative plate is annular current, and the annular current also generates a magnetic field. When the current directions in the positive plate and the negative plate are the same, the magnetic field directions are the same, and the magnetic fields are coupled and superimposed; otherwise, the magnetic field directions are opposite, and the magnetic fields cancel each other out. Due to the difference in size of the positive plate and the negative plate, the magnetic field generated by the current passing through the positive plate and the magnetic field generated by the current passing through the negative plate cannot be completely canceled out, so the magnetic field of the single winding core cannot be completely canceled out. Therefore, in the inventive concept proposed in the present application, two winding cores that are nested (which can be coaxially nested) inside and outside the battery are arranged, and in use, the electrode plates of the same polarity have opposite current directions in the two winding cores, so that the magnetic field generated by the inner winding core and the magnetic field generated by the outer winding core cancel each other out, and the coupling suppression effect of the magnetic field reaches the best.

[0038] Specifically, please refer to Figure 2 The battery provided by the embodiment of the present application comprises a first winding core 11, a second winding core 12 and a shell. In addition, Figure 2 For the convenience of description, only the parts related to the embodiment are shown. In actual application, the positive plate, the negative plate and the separator are separated by the separator, Figure 2 In order to clearly show the winding direction and the current direction of the positive plate and the negative plate, the separator is not shown. In addition, the positive plate, the separator and the negative plate are in contact in turn.

[0039] The first winding core 11 comprises a first positive plate 112 and a first negative plate 114, and the first winding core 11 generates a first magnetic field in use; the second winding core 12 comprises a second positive plate 122 and a second negative plate 124, and the second winding core 12 generates a second magnetic field in use; wherein the first winding core 11 is arranged in the second winding core 12, and in use, the current flowing through the first positive plate 112 and the current flowing through the second positive plate 122 have opposite directions, and the current flowing through the first negative plate 114 and the current flowing through the second negative plate 124 have opposite directions; the first winding core 11 and the second winding core 12 are arranged in the shell, so that the first magnetic field and the second magnetic field at least partially overlap and have opposite polarities, and thus the first magnetic field and the second magnetic field can cancel each other out, so that the external magnetic field radiation of the battery reaches the minimum. If the magnetic induction intensity of the first magnetic field and the magnetic induction intensity of the second magnetic field are equivalent, and the first magnetic field and the second magnetic field completely overlap, the battery will have no external magnetic field radiation.

[0040] Specifically, during charging and discharging, the current directions on the positive electrode sheets (112, 122) and the negative electrode sheets (114, 124) can be: the current directions of the first positive electrode sheet 112 and the first negative electrode sheet 114 are both clockwise (or counterclockwise), and the current directions of the second positive electrode sheet 122 and the second negative electrode sheet 124 are both counterclockwise (or clockwise); or the current direction of the first positive electrode sheet 112 is clockwise, the current direction of the first negative electrode sheet 114 is counterclockwise, the current direction of the second positive electrode sheet 122 is counterclockwise, and the current direction of the second negative electrode sheet 124 is clockwise. The current direction can also be other directions, which are only examples and are not considered as limitations to the present application.

[0041] Please refer to Figure 2 , Figure 2 The positive electrode sheet is represented by a dashed line, and the negative electrode sheet is represented by a solid line. In one embodiment, the first winding core 11 and the second winding core 12 are connected in series, the outer end of the first positive electrode sheet 112 is connected to the inner end of the second positive electrode sheet 122, and the outer end of the first negative electrode sheet 114 is connected to the outer end of the second negative electrode sheet 124. That is, it can be understood that the first positive electrode sheet 112 and the second positive electrode sheet 122 are the same electrode sheet, and the first negative electrode sheet 114 and the second negative electrode sheet 124 are the same electrode sheet. Then, the stacked positive electrode sheet, separator and negative electrode sheet are first wound in a clockwise direction (reference Figure 3A ) or counterclockwise direction (reference Figure 2 and Figure 3B ), and after a certain number of turns are wound, the positive electrode sheet, the separator and the negative electrode sheet are simultaneously wound in the opposite direction, so that the winding directions of the first winding core 11 and the second winding core 12 are opposite, and finally wound into a finished product winding core. During charging and discharging of the battery, the current directions of the two winding cores 11, 12 with opposite winding directions are opposite (as shown in Figure 2 ), and the directions of the magnetic fields generated thereby are opposite, which can be offset to suppress the overall external magnetic field of the battery.

[0042] Specifically, during winding of the core, the outer surface of the outermost turn of the first winding core 11 at the folding bend 20 changing the winding direction is fixedly connected by an insulating member 21, which can be double-sided adhesive tape or ordinary adhesive paper. The positive electrode sheet, the separator and the negative electrode sheet are wound in a clockwise (or counterclockwise) direction, and after a predetermined number of turns are reached, the fixing adhesive paper is attached, the winding direction is changed and the winding continues until the end of the winding, and the preparation of the winding core is completed. The folding bend 20 is fixed to the outermost turn of the first winding core 11 by the insulating member 21 to prevent the winding core from spreading out during reverse winding.

[0043] Please refer to Figure 4The surface of the positive electrode tab opposite to the negative electrode tab among the first positive electrode tab 112, the first negative electrode tab 114, the second positive electrode tab 122, and the second negative electrode tab 124 includes the active material, and the surface of the negative electrode tab opposite to the positive electrode tab includes the active material. It should be noted that the folding bend 20 is formed at the connection of the outer end of the first positive electrode tab 112 and the inner end of the second positive electrode tab 122, and the connection of the outer end of the first negative electrode tab 114 and the inner end of the second negative electrode tab 124, and the inner and outer surfaces of the folding bend 20 do not include the active material, which is mainly to prevent the electrode tab from being broken or powdering (i.e. the active material falls off) after being folded, affecting the electrical performance and safety performance of the battery.

[0044] Please refer to Figure 2 and Figure 4 Specifically, the positive electrode tab used is provided with two gaps, namely the BC section and the GF section, and the gap position only has a current collector (such as an aluminum foil), and the surface of the current collector is not coated with an active material, wherein the CG section and the BF section of the gap position are single-sided empty foil regions, that is, one side of the foil is coated with a positive electrode active material 31, and the other side of the foil is not coated with a positive electrode active material 31. The gap position GF (this part is a folding area, that is, the folding bend 20 which changes the winding direction) is a double-sided empty foil region, that is, the inner and outer surfaces of the foil are not coated with a positive electrode active material 31. Correspondingly, the negative electrode tab from the D point to the E point is an empty foil region, forming a gap (this gap is the folding bend 20), and the gap position is not coated with a negative electrode active material 32, that is, the inner and outer surfaces of the foil are not coated with a negative electrode active material 32.

[0045] The battery also includes a positive electrode tab 22 and a negative electrode tab 24, which are respectively arranged at the outer end of the second positive electrode tab 122 and the outer end of the second negative electrode tab 124. The positive electrode tab 22 is at the tail of the electrode tab, and after winding is completed, it is at the outermost circle of the battery, and the negative electrode tab 24 is also at the tail of the electrode tab, and after winding is completed, it is at the outermost circle of the battery. Considering the convenience and feasibility of manufacturing, the positive electrode tab 22 and the negative electrode tab 24 are in a non-overlapping structure (i.e. staggered at a certain distance), and the positive electrode tab 22 can be an aluminum tab, and the negative electrode tab 24 can be a nickel tab.

[0046] The winding directions of the first winding core 11 and the second winding core 12 based on the nested arrangement in the embodiment are opposite, and in use, the electrode sheets of the same polarity have opposite current directions in the two winding cores, the magnetic field generated by the first winding core 11 and the magnetic field generated by the second winding core 12 have the best coupling suppression effect; in the prior art, the winding core structure in which the two winding cores are arranged side by side, the magnetic fields generated in the charging and discharging process do not surround the periphery, and therefore the magnetic field offset effect is poor; the scheme in the embodiment has a higher space utilization rate of the winding core than the winding core in the non-nested arrangement, and has the advantage of high energy density; the winding structure winding core in the embodiment can be formed by winding once and then packaged, and has better manufacturability and higher production efficiency; the winding cores in the non-nested arrangement are wound respectively, and then the battery is welded and assembled, which has high operation complexity.

[0047] Please refer to Figure 5 , Figure 5 The positive electrode sheet is indicated by a dashed line, and the negative electrode sheet is indicated by a solid line. In one embodiment, the first positive electrode sheet 112 and the second positive electrode sheet 122 are different electrode sheets, the first negative electrode sheet 114 and the second negative electrode sheet 124 are different electrode sheets, and the first winding core 11 and the second winding core 12 are arranged in series or in parallel.

[0048] The embodiment adopts a nested scheme of two winding cores (the first winding core 11 and the second winding core 12), and the two nested winding cores are in series or in parallel. As shown in Figure 3A 、 Figure 3B and Figure 5 , in the charging and discharging process, the current directions of the first winding core 11 (the inner winding core) and the second winding core 12 (the outer winding core) are opposite, and therefore the magnetic field directions generated by the current are completely opposite and can offset each other. The winding directions of the first winding core 11 and the second winding core 12 can be the same or opposite. In the embodiment, the winding directions of the first winding core 11 and the second winding core 12 are opposite.

[0049] Please refer to Figure 5 , in the embodiment, each winding core has two tab leads of positive and negative poles, specifically, the battery includes an inner positive pole tab 221 arranged at the outer end of the first positive electrode sheet 112, an outer positive pole tab 241 arranged at the outer end of the second positive electrode sheet 122, an inner negative pole tab 222 arranged at the outer end of the first negative electrode sheet 114, and an outer negative pole tab 242 arranged at the outer end of the second negative electrode sheet 124; and a first connecting conductor 25 and a second connecting conductor 26. The first connecting conductor 25 and the second connecting conductor 26 can be a wire or a nickel strip, a copper strip, a copper-nickel composite strip, etc., the outer positive pole tab 222 and the inner positive pole tab 221 are aluminum tabs, and the outer negative pole tab 242 and the inner negative pole tab 241 are nickel tabs.

[0050] Wherein, when the first winding core 11 and the second winding core 12 are connected in series, the outer positive electrode tab 241 and the inner negative electrode tab 222 are electrically connected through the first connecting conductor 25, and the inner positive electrode tab 221 and the outer negative electrode tab 242 are electrically connected through the second connecting conductor 26, see Figure 5 . And, any one of the outer positive electrode tab 241, the inner negative electrode tab 222 and the first connecting conductor 25 is taken as the first lead-out tab, which is positive, and any one of the inner positive electrode tab 221, the outer negative electrode tab 242 and the second connecting conductor 26 is taken as the second lead-out tab, which is negative.

[0051] Wherein, when the first winding core 11 and the second winding core 12 are connected in parallel, the inner positive electrode tab 221 and the outer positive electrode tab 241 are electrically connected through the first connecting conductor 25, and the outer negative electrode tab 242 and the inner negative electrode tab 222 are electrically connected through the second connecting conductor 26. And, any one of the outer positive electrode tab 222, the inner positive electrode tab 221 and the first connecting conductor 25 is taken as the first lead-out tab, which is positive, and any one of the inner negative electrode tab 241, the outer negative electrode tab 242 and the second connecting conductor 26 is taken as the second lead-out tab, which is negative.

[0052] In this embodiment, the surfaces of the positive electrode tabs and the negative electrode tabs in the first positive electrode tab 112, the first negative electrode tab 114, the second positive electrode tab 122 and the second negative electrode tab 124, which are opposite to each other, respectively include the positive electrode active material 31 and the negative electrode active material 32, and the surface of the positive electrode tab which is not opposite to the negative electrode tab does not include the active material.

[0053] Please refer to Figure 2 and Figure 5 In the two embodiments, although the length and width of the (second) positive electrode tab 122 and the (second) negative electrode tab 124 in the outermost circle of the winding core are different, the magnetic fields generated by the current of the positive electrode tab 122 and the negative electrode tab 124 in the outermost circle cannot be cancelled out during charging or discharging; however, the scheme of the present application includes the nested inner winding core and outer winding core, and the magnetic field direction of the inner winding core and the magnetic field direction of the outer winding core are opposite during charging and discharging, which can be cancelled out, thereby inhibiting the external magnetic field of the whole battery.

[0054] It should be noted that, in combination with Figure 4 and Figure 5The positive electrode sheet including the positive electrode active material 31 must have a corresponding negative electrode sheet including the negative electrode active material 32, otherwise lithium is precipitated in the charging process, which is a safety hazard. The negative electrode sheet including the negative electrode active material 32 does not necessarily have a corresponding positive electrode sheet including the positive electrode active material 31. The outermost side of the outer winding core can be a positive electrode sheet, and the outermost side of the positive electrode sheet does not include the positive electrode active material 31, avoiding the precipitation of lithium in the charging process, which is a safety hazard (because there is no corresponding negative electrode active material 32). The outermost side of the outer winding core can also be a negative electrode sheet, and the outermost side of the negative electrode sheet can or can not include the negative electrode active material 32.

[0055] In the conventional battery structure, there is only one winding direction, and the winding core is a spiral winding structure. During charging and discharging, there is annular current. According to Ampere's law, the direction of the magnetic field generated by the current can be determined by the right-hand rule. However, since the winding direction and current direction of the inner winding core and the outer winding core of the present application are opposite, according to the right-hand rule, the directions of the magnetic fields generated by the two are also opposite and can cancel each other out.

[0056] It should be noted that in the embodiments of the present application, the winding directions of the first winding core 11 and the second winding core 12 are opposite, which can mean that the first winding core 11 is wound clockwise and the second winding core 12 is wound counterclockwise, or that the first winding core 11 is wound counterclockwise and the second winding core 12 is wound clockwise. In addition, the winding core is generally wound from the inside out.

[0057] From the above two embodiments, it can be seen that the nested battery of the present application can be realized by the following two embodiments:

[0058] Scheme one, please refer to Figure 2 , the inner winding core is first wound clockwise (or counterclockwise) and then the end adhesive tape is attached. The inner winding core is not removed from the winding device, and the rotation direction of the winding needle is reversed to counterclockwise (or clockwise). The inner winding core is used as the winding shaft again to wind the positive electrode sheet, the separator, and the negative electrode sheet. After winding is completed, the outer winding core is formed, the outer winding core is finished and the protective adhesive paper is attached, and the winding needle is removed. The number of battery winding cores can be greater than two.

[0059] Scheme two, please refer to Figure 5 , the inner winding core and the outer winding core are wound according to different winding directions. The inner winding core is placed in the center position of the outer winding core to form a nested winding core.

[0060] The nested battery of the present application has the following advantages:

[0061] (1) In conventional battery structures, the two winding cores are arranged in parallel. Although the directions of the magnetic fields generated by the two winding cores are opposite, the magnetic field cancellation effect is limited. In the solution mentioned in this application, the two winding cores are nested, and the magnetic fields generated by the two winding cores can be better cancelled out. Figure 6 .

[0062] (2) In conventional battery structures, the two roll cores are arranged in parallel, and there is a large gap between the two roll cores, which is not conducive to improving the overall battery energy density. In the solution of this application, the two roll cores are nested, which has better space utilization and is conducive to improving the overall battery energy density.

[0063] The second aspect of the embodiments of the present application further provides an audio playback device, including a speaker and the aforementioned battery. The technical solution of the present application improves upon the winding core, does not add external components, and has no impact on the structure of the audio playback device. Furthermore, after changing the winding direction, the current direction of the positive and negative electrodes inside the battery changes, and the directions of the magnetic fields generated by the two winding cores are completely opposite, effectively reducing the magnetic field generated during the battery's charging and discharging process.

[0064] 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 from a fundamental principle, which effectively reduces the external magnetic field of the battery. It has the advantages of low cost, no increase in size and space, and high efficiency. It 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.

[0065] 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: Comprising: a first jelly-roll comprising a first positive electrode sheet and a first negative electrode sheet, the first jelly-roll generating a first magnetic field when in use; a second jelly-roll comprising a second positive electrode sheet and a second negative electrode sheet, the second jelly-roll generating a second magnetic field when in use; wherein the first jelly-roll is disposed within the second jelly-roll, and when in use, the first positive electrode sheet flows current in a direction opposite to the direction of current flowing through the second positive electrode sheet, and the first negative electrode sheet flows current in a direction opposite to the direction of current flowing through the second negative electrode sheet; and a housing; the first jelly-roll and the second jelly-roll are arranged within the housing such that the first magnetic field and the second magnetic field at least partially overlap and have opposite polarities; among the first positive electrode sheet, the first negative electrode sheet, the second positive electrode sheet, and the second negative electrode sheet, the surface of the positive electrode sheet directly opposite to the negative electrode sheet comprises active material, and the surface of the negative electrode sheet directly opposite to the positive electrode sheet comprises active material; the surface of the positive electrode sheet not directly opposite to the negative electrode sheet does not comprise active material.

2. The battery of claim 1, wherein, the first jelly-roll and the second jelly-roll are arranged in series, the outer end of the first positive electrode sheet is connected to the inner end of the second positive electrode sheet, and the outer end of the first negative electrode sheet is connected to the inner end of the second negative electrode sheet.

3. The battery of claim 2, wherein the cathode comprises a lithium metal oxide. further comprising a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab are respectively arranged at the outer end of the second positive electrode sheet and the outer end of the second negative electrode sheet.

4. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. the first positive electrode sheet and the second positive electrode sheet are different electrode sheets, the first negative electrode sheet and the second negative electrode sheet are different electrode sheets, and the first jelly-roll and the second jelly-roll are arranged in series or in parallel.

5. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. the winding directions of the first jelly-roll and the second jelly-roll are opposite.

6. The battery of claim 1, wherein the cathode comprises a lithium metal oxide. the connection between the outer end of the first positive electrode sheet and the inner end of the second positive electrode sheet, and the connection between the outer end of the first negative electrode sheet and the inner end of the second negative electrode sheet form a fold bend, and the inner and outer surfaces of the fold bend do not comprise active material.

7. The battery of claim 6, wherein the cathode comprises a lithium metal oxide. the fold bend is fixedly connected to the outer surface of the first jelly-roll by an insulating member.

8. The battery of claim 4, wherein the cathode comprises a lithium cobalt oxide. further comprising an inner positive electrode tab arranged at the outer end of the first positive electrode sheet, an outer positive electrode tab arranged at the outer end of the second positive electrode sheet, an inner negative electrode tab arranged at the outer end of the first negative electrode sheet, and an outer negative electrode tab arranged at the outer end of the second negative electrode sheet; and a first connecting conductor and a second connecting conductor, wherein: the outer positive electrode tab is electrically connected to the inner negative electrode tab by the first connecting conductor, and the inner positive electrode tab is electrically connected to the outer negative electrode tab by the second connecting conductor; or the inner positive electrode tab is electrically connected to the outer positive electrode tab by the first connecting conductor, and the outer negative electrode tab is electrically connected to the inner negative electrode tab by the second connecting conductor.

9. An audio playback device comprising a loudspeaker, characterized in that further comprising the battery of any one of claims 1 to 8.

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