Battery roll core structure and battery

Abstract

The battery roll core structure comprises a positive pole piece, a negative pole piece, an inner diaphragm and an outer diaphragm, the outer diaphragm, the negative pole piece, the inner diaphragm and the positive pole piece are sequentially stacked and then curled into a battery roll core, and the negative pole piece and the positive pole piece are respectively stacked in wrapping areas of the outer diaphragm and the inner diaphragm when the battery roll core is curled. According to the battery roll core, only the outer diaphragm and the inner diaphragm are widened to wrap the wrapping areas of the negative plate and the positive plate, so that the negative plate and the positive plate can be completely separated by the outer diaphragm and the inner diaphragm, short circuit caused by direct contact of the two plates is prevented, the volume of the battery roll core is not increased, the content of electrolyte in the battery is increased, and the service life of the battery is prolonged. And the capacity of the battery with the same volume is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of battery coil cores, and in particular to a battery coil core structure and a battery. Background Art

[0002] When producing battery rolls, existing equipment needs to use a diaphragm to separate the negative and positive electrodes before wrapping them. The width of the diaphragm has a great impact on the production of the battery roll. If the width of the diaphragm is small, the positive and negative electrodes cannot be completely separated when wrapping them, which will cause hidden dangers in subsequent production. The size and volume of the battery are generally fixed. If the width of the diaphragm is large, although the positive and negative electrodes can be completely separated, the formed battery roll will be too high and too large. In order not to increase the volume of the battery, the electrolyte injected into the battery must be reduced, resulting in a smaller battery capacity. Utility Model Content

[0003] To solve the above problems, the present invention provides a battery coil structure and a battery. The specific technical solutions of the present invention are as follows:

[0004] A battery roll core structure, the battery roll core structure comprising: a positive electrode sheet, a negative electrode sheet, an inner separator and an outer separator, the positive electrode sheet and the negative electrode sheet having the same length, the width of the negative electrode sheet being greater than or equal to the width of the positive electrode sheet, and the outer separator and the inner separator having the same structure; the outer separator comprising a wrapping area and a curling area, the curling areas being respectively arranged on either side of the wrapping area, the length and width of the wrapping area being respectively greater than the length and width of the negative electrode sheet, and the width of the curling area being less than or equal to the width of the negative electrode sheet; the outer separator, the negative electrode sheet, the inner separator and the positive electrode sheet being stacked in sequence and curled into a battery roll core, wherein, during curling, the negative electrode sheet and the positive electrode sheet are respectively stacked on the wrapping areas of the outer separator and the inner separator.

[0005] Furthermore, the lengths of the curling areas on both sides of the wrapping area are the same.

[0006] Furthermore, the difference between the width of the outer separator and the width of the negative electrode sheet is N; wherein N is greater than 0 mm and less than or equal to 5 mm.

[0007] Furthermore, the width of the negative electrode sheet is greater than that of the positive electrode sheet, and the difference between the width of the negative electrode sheet and the width of the positive electrode sheet is M; wherein M is greater than 0 and less than or equal to 3 mm.

[0008] Furthermore, the width of the outer diaphragm is 101 mm.

[0009] Furthermore, the negative electrode sheet and the positive electrode sheet are respectively provided with metal contacts.

[0010] Furthermore, the thickness of the outer diaphragm and the inner diaphragm are equal, and the thickness of the outer diaphragm is greater than 0 mm and less than or equal to 1 mm.

[0011] Furthermore, the thickness of the negative electrode sheet is equal to that of the positive electrode sheet, and the thickness of the negative electrode sheet is greater than 0 mm and less than or equal to 1 mm.

[0012] A battery comprises an aluminum-plastic film, an electrolyte and a battery core, wherein the battery core has the above-mentioned battery core structure, a receiving cavity is provided in the aluminum-plastic film, and the battery core and the electrolyte are arranged in the receiving cavity.

[0013] Compared with the existing technology, the beneficial effect of the present invention is that: the battery roll core described in the present application only widens the outer diaphragm and the inner diaphragm for wrapping the negative electrode sheet and the positive electrode sheet, so that the outer diaphragm and the inner diaphragm can completely separate the negative electrode sheet and the positive electrode sheet to prevent the two electrodes from directly contacting and causing a short circuit, and the volume of the battery roll core will not be increased, the electrolyte content in the battery is increased, and the capacity of the battery of the same volume is higher; the width of the negative electrode sheet in the battery roll core is greater than or equal to the width of the positive electrode sheet, thereby improving the efficiency of battery charging and discharging. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of a half-unfolded battery roll core in one embodiment of the present invention;

[0015] Figure 2 This is a schematic structural diagram of a battery roll core after it is fully unfolded in one embodiment of the present invention;

[0016] Figure 3 This is a side view of a fully unfolded battery roll core in one embodiment of the present invention;

[0017] Figure 4 This is a front view of a battery roll core fully unfolded in one embodiment of the present invention. DETAILED DESCRIPTION

[0018] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions.

[0019] In the description of the present invention, it should be noted that, for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and so on, indicating directions and positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present invention.

[0020] 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. Therefore, the terms "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this utility model, "at least" means one or more, unless otherwise specifically defined.

[0021] In this utility model, unless otherwise specified or limited, the terms "assemble," "connect," and "connect" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection; direct connection, connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0022] In the utility model, unless otherwise specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "below," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "above," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0023] The following description of the embodiments of the present invention is provided in conjunction with the accompanying drawings to further describe the specific embodiments of the present invention so that the technical solutions and beneficial effects of the present invention are more clearly understood. The following description of the embodiments with reference to the accompanying drawings is for illustrative purposes only and is intended to explain the present invention, but is not to be construed as limiting the present invention.

[0024] like Figures 1 to 4As shown, a battery core structure comprises: a positive electrode sheet 1, a negative electrode sheet 3, an inner separator 2, and an outer separator 4. The positive electrode sheet 1 and the negative electrode sheet 3 have the same length, the negative electrode sheet 3 has a width greater than or equal to the width of the positive electrode sheet 1, and the outer separator 4 and the inner separator 2 have the same structure. The outer separator 4 includes a wrapping region 5 and a curling region 6, which are disposed on either side of the wrapping region 5. The length and width of the wrapping region 5 are respectively greater than the length and width of the negative electrode sheet 3, and the width of the curling region 6 is less than or equal to the width of the negative electrode sheet 3, i.e., the width W3 of the wrapping region 5 is greater than the width W2 of the negative electrode sheet 3. The outer separator 4, the negative electrode sheet 3, the inner separator 2, and the positive electrode sheet 1 are stacked in sequence and curled to form a battery core. After curling, the battery core can be secured with insulating tape. During curling, the negative electrode sheet 3 and the positive electrode sheet 1 are stacked on the wrapping regions 5 of the outer separator 4 and the inner separator 2, respectively.

[0025] As one embodiment, the lengths of the curling areas 6 on both sides of the wrapping area 5 are the same, and the length of the curling area 6 is set according to the size of the battery roll core and is not limited. Figure 4 As shown, when winding the battery core, the outer separator 4 and the inner separator 2 are first overlapped and laid together in the curling area 6 on their left sides, followed by one or two turns of curling. The negative electrode sheet 3 and the positive electrode sheet 1 are then added to the wrapping area 5 of the outer separator 4 and the inner separator 2, respectively, and then curled together. The outer separator 4 and the inner separator 2 completely wrap the positive electrode sheet 1 and the negative electrode sheet 3. The curling area 6 is used only for curling and does not separate the negative electrode sheet 3 and the positive electrode sheet 1. Therefore, there is no need to widen the curling area. While completely isolating the positive electrode sheet 1 and the negative electrode sheet, it also effectively reduces the volume of the battery core.

[0026] In one embodiment, the difference between the width W3 of the outer separator 4 and the width W2 of the negative electrode sheet 3 is N. Wherein, N is greater than 0 mm and less than or equal to 5 mm. Preferably, N is 3 mm.

[0027] In one embodiment, the width W2 of the negative electrode sheet 3 is greater than the width W1 of the positive electrode sheet 1 , and the difference between the width of the negative electrode sheet 3 and the width of the positive electrode sheet 1 is M. Wherein, M is greater than 0 and less than or equal to 3 mm. Preferably, M is 1 mm.

[0028] As one embodiment, the width of the outer diaphragm 4 is 101 mm.

[0029] As one embodiment, the negative electrode sheet 3 and the positive electrode sheet 1 are respectively provided with metal contacts 7. Figure 4As shown, when the negative electrode sheet 3 and the positive electrode sheet 1 are curled, the left boundaries of the negative electrode sheet 3 and the positive electrode sheet 1 are not aligned in the vertical direction, and the left edge of the negative electrode sheet 3 is set forward than the left edge of the positive electrode sheet 1. After curling, the metal contact heads of the negative electrode sheet 3 and the positive electrode sheet 1 will be separated and distributed on both sides of the battery roll core.

[0030] As one embodiment, the thickness of the outer diaphragm 4 and the inner diaphragm 2 are equal, and the thickness of the outer diaphragm 4 is greater than 0 mm and less than or equal to 1 mm.

[0031] As one embodiment, the thickness of the negative electrode sheet 3 is equal to that of the positive electrode sheet 1 , and the thickness of the negative electrode sheet 3 is greater than 0 mm and less than or equal to 1 mm.

[0032] A battery comprising an aluminum-plastic film, an electrolyte, and a battery core, the battery core having the aforementioned battery core structure, wherein the aluminum-plastic film is provided with a receiving cavity, and the battery core and electrolyte are disposed within the receiving cavity. The dimensions of square wound battery cores in the industry are relatively fixed, as is the battery housing used to house the battery core. If the volume of the battery core increases, the electrolyte needs to be reduced when placing the increased battery core into the battery housing, resulting in a reduction in battery capacity. If the electrolyte is not reduced, the battery volume will increase, which is inconsistent with industry standards and requires a new mold, increasing production costs.

[0033] The battery roll described in the present application only widens the wrapping area of ​​the outer diaphragm and the inner diaphragm for wrapping the negative electrode sheet and the positive electrode sheet, so that the outer diaphragm and the inner diaphragm can completely separate the negative electrode sheet and the positive electrode sheet to prevent the two electrode sheets from direct contact and causing a short circuit, while not increasing the volume of the battery roll core, increasing the electrolyte content in the battery, and making the capacity of the battery of the same volume higher; the width of the negative electrode sheet in the battery roll core is greater than or equal to the width of the positive electrode sheet, thereby improving the efficiency of battery charging and discharging.

[0034] In the description of the specification, reference to the terms "in one embodiment," "preferably," "example," "specific example," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. The schematic representations of the above terms in this specification do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. The connection method described in the description of the specification has obvious effects and practical effectiveness.

[0035] Through the description of the above structure and principle, technical personnel in the relevant technical field should understand that the present invention is not limited to the above specific implementation methods, and improvements and substitutions based on the present invention using the well-known technology in the field all fall within the scope of protection of the present invention and should be defined by the claims.

Claims

1. A battery core structure, characterized in that: The battery core structure includes: a positive electrode sheet, a negative electrode sheet, an inner separator and an outer separator, the positive electrode sheet and the negative electrode sheet have the same length, the width of the negative electrode sheet is greater than or equal to the width of the positive electrode sheet, and the outer separator and the inner separator have the same structure; The outer separator includes a wrapping area and a curling area, wherein the curling areas are respectively arranged on both sides of the wrapping area, the length and width of the wrapping area are respectively greater than the length and width of the negative electrode sheet, and the width of the curling area is less than or equal to the width of the negative electrode sheet; The outer separator, the negative electrode sheet, the inner separator and the positive electrode sheet are stacked in sequence and then rolled into a battery roll core, wherein, during rolling, the negative electrode sheet and the positive electrode sheet are stacked on the wrapping areas of the outer separator and the inner separator respectively.

2. The battery roll core structure according to claim 1, characterized in that: The lengths of the curling areas on both sides of the wrapping area are the same.

3. The battery roll core structure according to claim 1, characterized in that: The difference between the width of the outer separator and the width of the negative electrode sheet is N; wherein N is greater than 0 mm and less than or equal to 5 mm.

4. The battery roll core structure according to claim 1, characterized in that: The width of the negative electrode sheet is greater than that of the positive electrode sheet, and the difference between the width of the negative electrode sheet and the width of the positive electrode sheet is M; wherein M is greater than 0 and less than or equal to 3 mm.

5. The battery roll core structure according to claim 1, characterized in that: The width of the outer diaphragm is 101 mm.

6. The battery roll core structure according to claim 1, characterized in that: The negative electrode sheet and the positive electrode sheet are respectively provided with metal contacts.

7. The battery roll core structure according to claim 1, characterized in that: The outer diaphragm and the inner diaphragm have the same thickness, and the thickness of the outer diaphragm is greater than 0 mm and less than or equal to 1 mm.

8. The battery roll core structure according to claim 1, characterized in that: The thickness of the negative electrode sheet is equal to that of the positive electrode sheet, and the thickness of the negative electrode sheet is greater than 0 mm and less than or equal to 1 mm.

9. A battery, characterized in that: The battery includes an aluminum-plastic film, an electrolyte and a battery core. The battery core has the battery core structure according to any one of claims 1 to 8. A receiving cavity is provided in the aluminum-plastic film, and the battery core and the electrolyte are arranged in the receiving cavity.

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