Battery roll core and battery

Abstract

The battery roll core comprises a roll core main body, the roll core main body comprises a positive plate, a negative plate and a diaphragm which are wound, the diaphragm is positioned between the positive plate and the negative plate, and the roll core main body is provided with a central hole penetrating from one end of the roll core main body to the other end of the roll core main body. The positive plate, the negative plate and the diaphragm are wound by taking the central hole as a center, a solid body is arranged in the central hole, and a protective layer is arranged on the periphery of the solid body. The problem of short circuit of the battery cell caused by the fact that the thickness difference at the positive plate inlet position punctures the diaphragm during the tests of weight impact, extrusion and the like needing to press the roll cell is solved.

Description

Technical Field

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

[0002] With the rapid development of the new energy market, the demand for the use of lithium-ion batteries is getting higher and higher. The problem of lithium deposition caused by the collapse of the core part of the battery core has always affected the electrical performance and safety performance of lithium-ion batteries. Therefore, it is crucial to solve the problem of the collapse of the core part of the battery core and improve the cycle performance and internal short-circuit problem. Most of the existing research to solve such problems is to stick or coat glue at the negative electrode insertion position and the positive electrode insertion position to stabilize the electrode sheet, so that it will not bend under external force. This method can solve the problem, but sticking or coating glue on the electrode sheet will reduce the capacity of the battery cell, and the thickness difference of the electrode sheet will increase after sticking or coating glue, and there is a risk of lithium deposition at the place with the largest thickness difference. Summary of the Utility Model

[0003] Based on this, in view of the above technical problems, it is necessary to provide a battery core and a battery, which can provide good support for the core part of the core, prevent lithium deposition caused by the collapse of the core part of the core due to insufficient support force at the electrode head insertion position, and when performing tests such as heavy object impact and extrusion that require pressing the core, the thickness difference at the positive electrode insertion position will not pierce the separator, resulting in short circuit of the battery cell.

[0004] In a first aspect, the utility model provides a battery core, including a core body. The core body includes wound positive electrode sheets, negative electrode sheets and separators. The separators are located between the positive electrode sheets and the negative electrode sheets. The core body has a central hole penetrating from one end of the core body to the other end. The positive electrode sheets, negative electrode sheets and separators are wound around the central hole. An entity is provided in the central hole, and a protective layer is provided on the outer periphery of the entity.

[0005] As one of the embodiments, the protective layer is an oxide layer or a ceramic layer.

[0006] As one of the embodiments, the protective layer is an alumina layer or a zirconium boride-based ceramic layer.

[0007] As one of the embodiments, the entity is a column made of resin.

[0008] As one of the embodiments, the entity is a column made of PE resin.

[0009] As one of the embodiments, the entity is an aerogel filler.

[0010] As one of the embodiments, the aerogel filler is silica aerogel, alumina aerogel or ultra-light ceramic aerogel.

[0011] As one of the embodiments, the aperture of the central hole is 1 mm - 10 mm.

[0012] As one of the embodiments, the thickness of the protective layer is 0.1 mm - 1 mm.

[0013] As one of the embodiments, the protective layer is disposed on the surface of the entity facing the core body of the roll core, and / or the protective layer is disposed on the surface of the core body of the roll core facing the entity.

[0014] The second aspect of the present utility model further provides a battery, including the above-mentioned battery roll core.

[0015] The above introduces the battery roll core and the battery, which can not only provide good support for the core part of the roll core, prevent the core from collapsing and generating lithium deposition due to insufficient support force at the film inlet of the pole piece head, and secondly, when performing tests such as heavy object impact and extrusion that require pressing the roll core, the thickness difference at the film inlet of the positive pole will not pierce the separator and cause the battery cell to short-circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural view of the battery roll core of the present utility model;

[0017] Figure 2 is a schematic cross-sectional view of the battery roll core of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following further describes the battery roll core and the battery of the present utility model in conjunction with the embodiments:

[0019] Now, various exemplary embodiments of the present utility model will be described in detail. This detailed description should not be construed as a limitation of the present utility model, but should be understood as a more detailed description of certain aspects, characteristics, and implementation schemes of the present utility model. It should be understood that the terms described in the present utility model are only for describing specific implementation modes and are not used to limit the present utility model.

[0020] In addition, for the numerical ranges in the present utility model, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present utility model. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this utility model pertains. Although this utility model only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this utility model. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0022] Without departing from the scope or spirit of this utility model, various improvements and changes can be made to the specific embodiments of the specification of this utility model, which are obvious to those skilled in the art. Other embodiments obtained from the specification of this utility model are obvious to those skilled in the art. The specification and embodiments of this utility model are merely exemplary.

[0023] This embodiment provides a battery core, which can avoid the diaphragm being punctured due to the thickness difference at the positive electrode insertion position during tests that require pressing the core, such as heavy object impact and extrusion, without modifying the electrode sheets, consuming the positive and negative electrode materials, or reducing the capacity.

[0024] See Figure 1-2 , the battery core includes a core body 1. The core body 1 includes wound positive electrode sheets, negative electrode sheets, and a separator. The separator is located between the positive electrode sheets and the negative electrode sheets. The positive electrode sheets and the negative electrode sheets are respectively made of conductive electrode materials, and the separator is an insulating material. Among them, the core body 1 has a central hole penetrating from one end to the other end of the core body 1. The positive electrode sheets, negative electrode sheets, and separator are wound around the central hole, and a solid body 2 is filled in the central hole. The solid solid body 2 can play a good supporting role to prevent lithium deposition caused by the insufficient supporting force at the electrode head insertion position and the core collapse.

[0025] In this embodiment, a protective layer 3 is provided on the outer periphery of the solid body 2. Among them, the protective layer 3 can be an oxide layer or a ceramic layer. The oxide layer is preferably an alumina layer, and can also be a copper oxide layer. The ceramic layer is preferably a zirconium boride-based ceramic layer, and can also be a zirconia ceramic. The alumina layer or the zirconium boride-based ceramic layer can better enhance the compressive strength of the solid body 2, and at the same time can also play the roles of high temperature resistance, corrosion resistance, and insulation. Although only using the solid body 2 can play a good supporting role, during tests that require pressing the core, such as heavy object impact and extrusion, there will still be a problem that the insufficient support causes the thickness difference at the positive electrode insertion position to pierce the diaphragm and then cause a short circuit of the battery cell. Therefore, setting the protective layer 3 on the outer periphery of the solid body 2 can effectively prevent the occurrence of the above problems.

[0026] In some embodiments, the entity 2 can be a column made of resin. The resin is preferably PE resin, and can also be polystyrene resin or polytetrafluoroethylene resin. The oxide or ceramic material is coated on the periphery of the entity 2 to form an oxide layer or a ceramic layer. The resin has stable chemical stability and good corrosion resistance. It will not cause electrolyte pollution during use. At the same time, it has good mechanical processing performance. It has a certain hardness and plays a supporting role. It is also flexible and not easy to break. It prevents the entity 2 from being broken during the impact and extrusion test of heavy objects and piercing the diaphragm to cause a short circuit of the battery cell. It can also resist the expansion of the battery core. Among them, in some examples, the protective layer 3 can be coated on the surface of the entity 2 facing the core body 1. In other examples, the protective layer 3 can also be coated on the surface of the core body 1 facing the entity 2, or the protective layer 3 is coated on the surface of the core body 1 facing the entity 2 and the surface of the entity 2 facing the core body 1.

[0027] In other embodiments, the entity 2 may be an aerogel filler. Aerogel fillers include, but are not limited to, silicon oxide aerogel, aluminum oxide aerogel, or ultralight ceramic aerogel, etc. Aerogel fillers are both resistant to high temperatures and elastic. As an ultra-light solid material, they can also reduce mass and thus increase the energy density of the battery core. Moreover, while playing a supporting role, they release space for the core to expand, avoiding the breakage of the pole piece in the core, which is beneficial to maintaining the performance of the battery. Aerogel fillers can also be recycled and reused to save costs. In this embodiment, an oxide or ceramic material is coated on the wall of the positive or negative pole piece corresponding to the center hole of the core body 1 to form an oxide layer or a ceramic layer, and then filled with an aerogel filler. Among them, the aerogel filler can be used as a protective layer 3 to increase a certain rigidity, thereby improving the supporting effect of the aerogel filler. Among them, the protective layer 3 is provided on the surface of the core body 1 facing the entity 2.

[0028] Among them, the size of the entity 2 after matching with the protective layer 3 is adapted to the size of the center hole. In this embodiment, the aperture of the center hole is 1mm-10mm, preferably 3mm-7mm, for example, it can be 1mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm, etc. The aperture of the center hole needs to be within a suitable range. If it is too large, the entity will easily occupy the electrode sheet space and reduce the core capacity. If it is too small, the entity will be too thin and cannot play a substantial supporting role. For the entity 2 used in the embodiment of the utility model, such as resin and aerogel, the above range can not only ensure a certain support strength, but also try to avoid reducing the core capacity.

[0029] In one embodiment, the thickness of the protective layer 3 is 0.01 mm - 1 mm, preferably 0.1 mm - 0.5 mm. For example, it can be 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 1.0 mm, and so on. This thickness can enhance the support strength while avoiding reducing the core capacity of the roll.

[0030] An embodiment of the present utility model further provides a battery, including a housing and the above-mentioned battery core. Among them, the battery core is installed in the housing.

[0031] By designing the entity 2 to support and cooperate with the protective layer 3, the present utility model not only solves the problem of core collapse of the battery cell, improves the problem of lithium plating caused by collapse during the use of the battery, but also when conducting tests such as heavy object impact and extrusion that require pressing the core, the thickness difference at the positive electrode insertion point will pierce the separator, resulting in a short circuit problem of the battery cell, thereby improving the cycle electrical performance and safety performance of the battery cell. Compared with pasting or coating the electrode sheet, it will not reduce the capacity of the battery cell; nor will it occupy the internal space of the battery like pasting or coating.

[0032] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as within the scope described in this specification.

[0033] The above-described embodiments only represent several implementation manners of the present utility model. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the appended claims.

Claims

1. A battery roll core, comprising a roll core body, wherein the roll core body comprises a wound positive electrode sheet, a wound negative electrode sheet and a separator, wherein the separator is located between the positive electrode sheet and the wound negative electrode sheet, wherein: The winding core body has a central hole extending from one end of the winding core body to the other end. The positive electrode sheet, the negative electrode sheet and the separator are wound around the central hole. A solid body is arranged in the central hole, and a protective layer is arranged around the solid body.

2. The battery roll core according to claim 1, characterized in that: The protective layer is an oxide layer or a ceramic layer.

3. The battery roll core according to claim 2, characterized in that: The protective layer is an aluminum oxide layer or a zirconium boride-based ceramic layer.

4. The battery roll core according to claim 1, characterized in that: The entity is a column made of resin.

5. The battery roll core according to claim 4, characterized in that: The entity is a column made of PE resin.

6. The battery roll core according to claim 1, characterized in that: The entity is an aerogel filler.

7. The battery roll core according to claim 6, characterized in that: The aerogel filler is silicon oxide aerogel, aluminum oxide aerogel or ultra-light ceramic aerogel.

8. The battery roll core according to claim 1, characterized in that: The diameter of the central hole is 1 mm-10 mm.

9. The battery roll core according to claim 1, characterized in that: The thickness of the protective layer is 0.1 mm-1 mm.

10. The battery roll core according to claim 1, characterized in that: The protective layer is disposed on a surface of the entity facing the core body, and / or the protective layer is disposed on a surface of the core body facing the entity.

11. A battery, characterized in that: A battery roll core comprising any one of claims 1 to 10.

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