Battery cell structure and battery

Abstract

The utility model provides a battery cell structure and a battery. The battery cell structure comprises a battery cell body; the diaphragm bag is provided with an accommodating space, the upper end of the diaphragm bag is provided with an opening communicated with the accommodating space, the diaphragm bag sleeves the outer surface of the battery cell body from bottom to top, and at least one part of the battery cell body is accommodated outside the accommodating space. According to the utility model, the problem of poor safety performance of the battery cell in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery technical field, specifically, relate to a kind of battery cell structure and battery. BACKGROUND

[0002] Lithium ion battery as a kind of secondary battery, battery energy density is high, self-discharge is small, long life, use safety, pollution-free, is the main choice in contemporary various new energy applications.

[0003] In the manufacturing process of battery, need to carry out cell into shell, i.e. cell assembly into shell. In order to prevent the outer layer of cell from being scratched in the process of cell into shell and causing pole piece defect and internal short circuit of cell, the existing solution is generally to set an insulating layer on the outer surface of cell, to avoid the outer layer of cell from being damaged by contacting with shell, however, the insulating layer generally completely wraps the cell, which will aggravate the heat generation of cell, affect heat dissipation, and thus affect the safety performance of cell.

[0004] As known from the above, the safety performance of cell in the related art is poor. UTILITY MODEL CONTENT

[0005] The main purpose of the utility model is to provide a kind of battery cell structure and battery, to solve the problem of poor safety performance of cell in the related art.

[0006] In order to achieve the above purpose, according to one aspect of the utility model, a kind of battery cell structure is provided, comprising: cell body;Diaphragm bag, diaphragm bag has accommodating space, the upper end of diaphragm bag has the opening communicated with accommodating space, diaphragm bag is set on the outer surface of cell body from below to above, and at least a part of cell body is accommodated outside accommodating space.

[0007] Further, the material of diaphragm bag is any one of PP, PE or PET.

[0008] Further, diaphragm bag is composite film.

[0009] Further, composite film is multilayer, the material of each layer of composite film is any one of PP, PE or PET, and the material of at least two layers in multilayer composite film is different.

[0010] Further, the upper end of diaphragm bag is located at 1 / 2 to 3 / 4 of the height of cell body.

[0011] Further, the thickness of diaphragm bag is 20 μm to 40 μm.

[0012] Further, diaphragm bag is multilayer, and each layer of diaphragm bag is stacked.

[0013] Further, the diaphragm bag comprises a first bag body and a second bag body which are folded, and the first bag body and the second bag body are respectively attached to two large faces of the battery cell body, and two side edges of the first bag body and the second bag body are connected and closed at two ends of the battery cell body.

[0014] Further, the two side edges of the first bag body and the second bag body are heat-sealed.

[0015] According to another aspect of the present application, a battery is also provided, comprising the above-mentioned battery cell structure.

[0016] The technical scheme of the present application comprises a battery cell body and a diaphragm bag, the diaphragm bag has a containing space, the upper end of the diaphragm bag has an opening which is communicated with the containing space, the diaphragm bag is sleeved on the outer surface of the battery cell body from bottom to top, and at least a part of the battery cell body is contained outside the containing space, so that the lower part of the battery cell body is covered by the diaphragm bag instead of being entirely covered, which can avoid the outer layer being scratched and broken during the process of the battery cell entering the shell, resulting in poor pole piece and internal short circuit, and can also avoid the heat production of the battery cell being intensified to affect heat dissipation, and the bottom end of the battery cell body can also avoid being in contact with the bottom of the shell to prevent the pole piece from being short-circuited with the metal shell, greatly improving the safety performance of the battery cell, and solving the problem of poor safety performance of the battery cell in the related art. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 Fig. 1 shows a structure schematic diagram of a diaphragm bag according to one specific embodiment of the present application;

[0019] Figure 2 Fig. 2 shows a structure schematic diagram of a battery cell structure according to one specific embodiment of the present application.

[0020] Among them, the above-mentioned drawings comprise the following reference signs:

[0021] 10, battery cell body; 20, diaphragm bag; 21, first bag body; 22, second bag body. DETAILED DESCRIPTION

[0022] Clearly, the described embodiments are merely a part of the embodiments of the present application, but not all the embodiments. The description of the at least one exemplary embodiment is merely illustrative in nature and is in no way to be construed as any limitation on the present application and its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0024] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless otherwise specifically stated. At the same time, it should be understood that the sizes of the various parts shown in the drawings are not drawn in proportion to the actual proportions. The techniques, methods and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but in appropriate cases, the techniques, methods and devices should be considered as part of the authorized description. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0025] In order to solve the problem of poor safety performance of the electric core in the related art, the present application provides an electric core structure and a battery.

[0026] As shown in Figure 2 The electric core structure includes an electric core body 10 and a diaphragm bag 20. The diaphragm bag 20 has a containing space, the upper end of the diaphragm bag 20 has an opening communicating with the containing space, the diaphragm bag 20 is sleeved on the outer surface of the electric core body 10 from bottom to top, and at least a part of the electric core body 10 is contained outside the containing space.

[0027] The existing battery shell has the risk of burr inside, the outer layer is scratched during the process of the cell entering the shell, which causes internal micro-short circuit of the cell, after the cell enters the shell, the bottom end of the cell is close to the bottom of the shell, and the cell touches the bottom of the shell in the use scene to cause short circuit, further, the existing cell generally completely wraps the cell when wrapping the insulating layer on the surface of the cell, which aggravates the heat generation of the cell and affects heat dissipation. By setting the cell structure including the cell body 10 and the diaphragm bag 20, the diaphragm bag 20 has a containing space, the upper end of the diaphragm bag 20 has an opening communicating with the containing space, the diaphragm bag 20 is sleeved on the outer surface of the cell body 10 from bottom to top, and at least a part of the cell body 10 is contained outside the containing space, so that the diaphragm bag 20 wraps the lower part of the cell body 10 instead of the whole, which avoids the risk of burr inside, the outer layer is scratched during the process of the cell entering the shell, which causes internal micro-short circuit of the cell, and also avoids the heat generation of the cell, which affects heat dissipation, guarantees the heat dissipation performance of the cell, and the bottom end of the cell body 10 can also avoid contacting the bottom of the shell to prevent short circuit of the pole piece and the metal shell, greatly improving the safety performance of the cell. In addition, by setting the diaphragm bag 20, the cell body 10 can be effectively restrained, the cell swelling problem can be relieved, the cell can be better positioned, the temperature rise change of the outer surface of the cell in high temperature short circuit can be slowed down, and the safety and reliability of the product are further improved.

[0028] As shown in Figure 1 , the diaphragm bag 20 includes a first bag body 21 and a second bag body 22 which are folded, the first bag body 21 and the second bag body 22 are respectively attached to the two large faces of the cell body 10, and the two side edges of the first bag body 21 and the second bag body 22 are connected and closed at the two ends of the cell body 10.

[0029] In the embodiment, the two side edges of the first bag body 21 and the second bag body 22 are heat-sealed. Of course, the two side edges of the first bag body 21 and the second bag body 22 can also be connected in other forms, such as bonding, sewing, etc., which can be selected according to actual needs.

[0030] Specifically, the diaphragm bag 20 is a rectangular structure before being sealed, and Figure 2 , the cell body 10 is in a vertical state, that is, the two large faces of the cell body 10 are respectively towards the two horizontal sides, the diaphragm bag 20 is folded upwards and downwards to form the first bag body 21 and the second bag body 22, the folding part is used to attach to the bottom of the cell body 10, and the first bag body 21 and the second bag body 22 correspond to the two sides of the cell body 10 respectively, so as to be attached to the two large faces. Then the two side edges of the first bag body 21 and the second bag body 22 are heat-sealed from bottom to top, so that the two side edges of the first bag body 21 and the second bag body 22 can be closed and attached to the two side faces of the cell body 10 to form a bag body structure, and the upper end of the diaphragm bag 20 forms an opening.

[0031] It can be understood that, in order to ensure the effect of heat sealing, the size of the diaphragm bag 20 before being packaged is larger than the size of the outer surface of the battery core body 10, and after heat sealing, the excess diaphragm on both sides along the sealing area is cut off, so that the width of the diaphragm bag 20 is consistent with the width of the battery core body 10, thereby ensuring that the battery core body 10 and the diaphragm bag 20 are closely attached.

[0032] In the present embodiment, the upper end of the diaphragm bag 20 is located at 1 / 2 to 3 / 4 of the height of the battery core body 10. In the case that the diaphragm bag 20 does not completely cover the battery core body 10, by reasonably setting the area of the diaphragm bag 20 attached to the battery core body 10, it can avoid the outer layer being scratched during the process of the battery core entering the shell, which leads to the poor pole piece and internal short circuit, and also avoid the heat generation of the battery core to affect heat dissipation, thereby ensuring the safety performance of the battery core.

[0033] Preferably, the upper end of the diaphragm bag 20 is located at 3 / 4 of the height of the battery core body 10.

[0034] In the present embodiment, the thickness of the diaphragm bag 20 is 20 μm to 40 μm. By reasonably setting the thickness of the diaphragm bag 20, the diaphragm bag 20 has sufficient structural strength while not being easy to shrink during heat sealing treatment, ensuring the heat sealing connection effect of the bag body edge so that the diaphragm bag 20 is closely attached to the outer surface of the battery core body 10, avoiding wrinkles.

[0035] In the present embodiment, the diaphragm bag 20 is single-layer. Further, the material of the diaphragm bag 20 is any one of PP (polypropylene), PE (polyethylene) or PET (polyethylene terephthalate). The above-mentioned materials have good insulation and good structural strength, so that the diaphragm bag 20 is not easy to be worn out while having sufficient insulation performance, thereby effectively preventing internal short circuit of the battery.

[0036] In an optional embodiment, the diaphragm bag 20 is a composite film. The composite film is multi-layered, each layer of the composite film is made of any one of PP, PE or PET, and at least two layers of the multi-layered composite film are made of different materials. Specifically, the diaphragm bag 20 is a three-layer structure, for example, the diaphragm bag 20 can be a PE / PP / PE composite film, that is, the diaphragm bag 20 is a sandwich-like structure, in which case, the diaphragm bag 20 can also be a PET / PP / PET composite film, or a PP / PE / PP composite film, etc. Of course, the diaphragm bag 20 can also be a PE / PP / PET composite film, or a PP / PE / PET composite film, etc. Further, the diaphragm bag 20 can also be a two-layer structure or a structure of more than four layers, which can be selected according to actual needs. By adopting the composite film structure, the insulation performance and structural strength of the diaphragm bag 20 can be improved, so that the diaphragm bag 20 is not easy to be damaged and has sufficient insulation. Further, the diaphragm bag 20 can also be other types of composite films, for example, the middle layer is made of PE material, and the two edge layers are made of aluminum oxide, boehmite or inorganic solid electrolyte, etc., which can be selected according to actual needs.

[0037] In an optional embodiment, the diaphragm bag 20 is multi-layered, and each layer of the diaphragm bag 20 is stacked. Specifically, the diaphragm bag 20 can be two layers, and the two layers of the diaphragm bag 20 are stacked, which can also be understood as that the cell structure includes two single-layer diaphragm bags 20 nested inside and outside. Further, for each layer of the diaphragm bag 20, both layers can be single-layer films or composite films, or one layer can be a single-layer film and the other layer can be a composite film, which can be selected according to actual needs.

[0038] The application also provides a battery comprising the above-mentioned cell structure.

[0039] The cell insertion process of the application is as follows:

[0040] The insulating material is cut to a size suitable for the cell body 10, the insulating material is folded in half and then wrapped around a part of the height of the cell body 10 in the longitudinal direction from bottom to top, and the two sides are sealed by a heat sealing machine and then the excess part is trimmed to form the diaphragm bag 20, at this time the diaphragm bag 20 is wrapped around the middle and lower part of the cell body 10; the cell structure wrapped with the diaphragm bag 20 is vertically inserted into the battery shell, and the cap assembly welding is completed.

[0041] From the above description, it can be seen that the above-mentioned embodiments of the utility model realize the following technical effects: through setting the battery cell structure includes battery cell body 10 and diaphragm bag 20, diaphragm bag 20 has the accommodation space, the upper end of diaphragm bag 20 has the opening with the accommodation space intercommunication, diaphragm bag 20 is set from below to the outer surface of battery cell body 10, and at least a part of battery cell body 10 is accommodated in the accommodation space, so that diaphragm bag 20 covers the lower part of battery cell body 10 instead of all, while avoiding the outer layer being scratched and broken during the process of battery cell into the shell, leading to the pole piece bad and internal short circuit, still can avoid the heat production of battery cell aggravating and influence heat dissipation, guarantee the heat dissipation performance of battery cell, and the bottom end of battery cell body 10 can also avoid contacting with the bottom of shell, prevent the short circuit of pole piece and metal shell, greatly improve the safety performance of battery cell.In addition, by setting diaphragm bag 20, battery cell body 10 can be effectively bound, the battery cell expansion problem is relieved, so that the battery cell is better positioned, and the temperature rise change of the outer surface of the battery cell during high-temperature short circuit is also slowed down, further improving the safety and reliability of the product.

[0042] In the description of the utility model, it is understood that the orientation words such as '' front, back, up, down, left, right '' '' horizontal, vertical, perpendicular, horizontal '' and '' top, bottom '' and the like indicated orientation or position relationship usually is based on the orientation or position relationship shown in the drawing, just for the convenience of describing the utility model and simplifying the description, in the case where no opposite statement is made, these orientation words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore it can not be understood as the limitation to the protection scope of the utility model;The orientation words '' inside, outside '' refer to the inside and outside relative to the contour of each component.

[0043] For the convenience of description, spatial relative terms such as '' above'', '' above'', '' upper surface'', '' upper '' and the like can be used here to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawing.It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawing.For example, if the device in the drawing is inverted, the device described as '' above '' or '' above '' other devices or structures will be positioned '' below '' or '' below '' other devices or structures.Exemplary terms '' above '' can include both '' above '' and '' below '' orientations.The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative description used here is interpreted accordingly.

[0044] In addition, it needs to be explained that the use of "first", "second" and the like to limit the parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning if there is no further declaration, and therefore cannot be understood as limiting the protection scope of the utility model.

[0045] The above only describes the preferred embodiments of the utility model, and is not used to limit the utility model. For those skilled in the art, the utility model can have various changes and variations. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An electric cell structure, characterized by comprising: The battery cell structure comprises: a battery cell body (10); a diaphragm bag (20) having a containing space, an upper end of the diaphragm bag (20) having an opening communicating with the containing space, the diaphragm bag (20) being sleeved on an outer surface of the battery cell body (10) from bottom to top, and at least a part of the battery cell body (10) being contained outside the containing space.

2. The cell structure of claim 1, wherein, The diaphragm bag (20) is made of any one of PP, PE or PET.

3. The cell structure of claim 1, wherein, The diaphragm bag (20) is a composite film.

4. The cell structure of claim 3, wherein, The composite film is multilayered, each layer of the composite film being made of any one of PP, PE or PET, and at least two layers of the multilayered composite film being made of different materials.

5. The cell structure of claim 1, wherein, The upper end of the diaphragm bag (20) is located at 1 / 2 to 3 / 4 of the height of the battery cell body (10).

6. The cell structure of claim 1, wherein, The diaphragm bag (20) has a thickness of 20 μm to 40 μm.

7. The cell structure of claim 1, wherein, The diaphragm bag (20) is multilayered, each layer of the diaphragm bag (20) being stacked.

8. The cell structure of claim 1, wherein, The diaphragm bag (20) comprises a first bag body (21) and a second bag body (22) which are folded, the first bag body (21) and the second bag body (22) being respectively attached to two large faces of the battery cell body (10), and two side edges of the first bag body (21) and the second bag body (22) being connected and closed at two ends of the battery cell body (10).

9. The cell structure of claim 8, wherein, The two side edges of the first bag body (21) and the second bag body (22) are heat-sealed.

10. A battery, characterized by The battery cell structure of any one of claims 1 to 9 is included.

Images