Battery

Abstract

The utility model discloses a battery which comprises battery monomers and protective films, a plurality of battery monomers are overlapped along a first direction, the side wall of a shell of each battery monomer in the first direction is a first side wall, the side wall of the shell in the second direction is a second side wall, and the protective films comprise a first protective film and a second protective film. The first protective film is pasted on the outer surface of the first side wall, the second protective film is pasted on the outer surface of the second side wall, the first protective film comprises a first film layer and a first bonding layer, the second protective film comprises a second film layer and a second bonding layer, and the bonding strength of the second bonding layer is larger than that of the first bonding layer. According to the battery disclosed by the utility model, the first protective film with slightly poor bonding strength is adhered to the first side wall, and the second protective film with higher bonding strength is adhered to the second side wall, so that the battery can be better insulated and protected, and the cost can be effectively reduced.

Description

Technical Field

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

[0002] In related technologies, the outer aluminum shell of the power battery cell mostly relies on pasting a protective film to achieve insulation and protection functions. Currently, the common protective film needs to be bonded to the battery pack bottom plate, water cooling plate, upper cover, etc. with a structural adhesive with a bonding strength of 7 Mpa. This solution requires the bonding strength between the protective film and the cell aluminum shell to be greater than or equal to 7 Mpa. However, the commonly used structural adhesive for the protective film is pressure-sensitive adhesive, and the bonding strength between the pressure-sensitive adhesive and the aluminum shell is about 2 Mpa, which often easily causes the bonding between the protective film and the aluminum shell to break, resulting in the separation of the protective film and the aluminum shell, and further leading to short circuits or other problems inside the battery. If the protective film directly uses a UV adhesive with a higher bonding strength, the cost is likely to increase. In some other related technologies, windows are provided on the protective film, so that when the aluminum shell is bonded to the battery pack bottom plate, water cooling plate, upper cover, etc., the structural adhesive is directly applied to the aluminum shell. However, if the glue cannot completely cover the surface of the window in this solution, there is a risk of insulation failure, leading to serious electrical safety accidents. Content of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. To this end, an object of the utility model is to propose a battery, and the protective film of the battery can not only better insulate and protect the battery, but also effectively reduce the cost.

[0004] The battery according to an embodiment of the utility model includes: a plurality of battery cells, the plurality of battery cells are stacked along a first direction, a side wall of the cell housing in the first direction is a first side wall, a side wall of the housing in a second direction is a second side wall, and the first direction and the second direction are perpendicular to each other; a protective film, the protective film wraps the outer surface of the housing, the protective film includes a first protective film and a second protective film, the first protective film is pasted on the outer surface of the first side wall, the second protective film is pasted on the outer surface of the second side wall, wherein, the first protective film includes a first film layer and a first bonding layer, the second protective film includes a second film layer and a second bonding layer, and the bonding strength of the second bonding layer is greater than that of the first bonding layer.

[0005] For the battery according to an embodiment of the utility model, by pasting the first protective film with a slightly worse bonding strength on the first side wall and pasting the second protective film with a higher bonding strength on the second side wall, it can not only better insulate and protect the battery, but also effectively reduce the cost.

[0006] In addition, the battery according to the utility model further has the following additional technical features:

[0007] In some embodiments of the present utility model, the first protective film has a first overlapping area, the second protective film has a second overlapping area, and at least a part of the first overlapping area and at least a part of the second overlapping area are bonded to construct a composite area.

[0008] In some embodiments of the present utility model, the second protective film extends to the outer surface of the first side wall to construct the second overlapping area overlapping with the first protective film on the outer surface of the first side wall.

[0009] In some embodiments of the present utility model, there is an arc transition part between the first side wall and the second side wall. The second protective film has a main body area pasted on the second side wall, an arc transition area pasted on the outer surface of the arc transition part, and the second overlapping area pasted on the first side wall. The second overlapping area is located on the side of the arc transition area away from the main body area.

[0010] In some embodiments of the present utility model, in the direction from the first protective film to the second protective film, the width H1 of the composite area is greater than or equal to 5 mm.

[0011] In some embodiments of the present utility model, the thickness T1 of the second film layer and the thickness T2 of the second adhesive layer satisfy: 0.8 ≤ T1 / T2 ≤ 5.

[0012] In some embodiments of the present utility model, at least one of the second protective films is provided on one side of the battery in the second direction, and the second protective film is pasted on the second side walls of at least two battery monomers.

[0013] In some embodiments of the present utility model, the second protective film is pasted on a plurality of the second side walls, and in the first direction, both ends of the second protective film respectively extend to two first side walls at both ends of the battery. Wherein, the first protective film extends to the second side wall.

[0014] In some embodiments of the present utility model, the first adhesive layer is composed of a pressure-sensitive adhesive, and the second adhesive layer is composed of a UV adhesive.

[0015] In some embodiments of the present utility model, the battery includes a battery case, and a plurality of the battery monomers and the protective film are all installed in the battery case.

[0016] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0017] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 is a schematic structural diagram of a battery according to an embodiment of the present utility model.

[0019] Figure 2 is Figure 1 an enlarged view of region A in

[0020] Figure 3 is a cross-sectional view of a battery according to an embodiment of the present utility model.

[0021] Figure 4 is Figure 3 an enlarged view of region B in

[0022] Figure 5 is a schematic structural diagram of a battery cell of a battery according to an embodiment of the present utility model.

[0023] Figure 6 is Figure 5 an enlarged view of region C in

[0024] Figure 7 is a cross-sectional view of a battery cell of a battery according to an embodiment of the present utility model.

[0025] Figure 8 is Figure 7 an enlarged view of region D in

[0026] Reference numerals:

[0027] battery 100,

[0028] battery cell 1, first side wall 11, second side wall 12,

[0029] protective film 2, first protective film 21, first overlapping region 211,

[0030] second protective film 22, second overlapping region 221, main body region 222, arc transition region 223. Detailed implementation manners

[0031] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model.

[0032] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0033] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0034] Next, reference is made to Figures 1-8 Describe the battery 100 according to an embodiment of the present utility model.

[0035] As Figures 1-8 shown, the battery 100 according to an embodiment of the present utility model includes a plurality of battery cells 1. The plurality of battery cells 1 are stacked along a first direction. The side wall of the housing of the battery cell 1 in the first direction is the first side wall 11, and the side wall of the housing in the second direction is the second side wall 12. The first direction and the second direction are perpendicular to each other.

[0036] Referring to the attached Figure 1 shown, the first direction can be referred to as the front - rear direction, and the second direction can be referred to as the up - down direction. It can be understood that both of the two side walls of the housing in the front - rear direction can be called the first side wall 11, and both of the two side walls of the housing in the up - down direction can be called the second side wall 12. Here, the first side wall 11 and the second side wall 12 are only for the convenience of describing the present application, rather than a specific limitation to the present application. In this example, the area of the first side wall 11 is larger than the area of the second side wall 12.

[0037] Furthermore, the protective film 2 is wrapped around the outer surface of the housing. The protective film 2 includes a first protective film 21 and a second protective film 22. The first protective film 21 is pasted on the outer surface of the first side wall 11, and the second protective film 22 is pasted on the outer surface of the second side wall 12. Among them, the first protective film 21 includes a first film layer and a first adhesive layer, and the second protective film 22 includes a second film layer and a second adhesive layer. The adhesive strength of the second adhesive layer is greater than that of the first adhesive layer.

[0038] Exemplarily, as Figures 1-8 shown, the first protective film 21 can be pasted on both of the two first side walls 11, and the second protective film 22 can be pasted on both of the two second side walls 12. In terms of the pasting sequence, the first protective film 21 can be pasted on the two first side walls 11 first, and then the second protective film 22 can be pasted on the second side walls 12. Or, the second protective film 22 can be pasted on the two second side walls 12 first, and then the first protective film 21 can be pasted on the first side walls 11. This application does not make any restrictions.

[0039] In the related art, most of the external parts of the battery cells' aluminum shells in power batteries rely on pasting protective films to achieve insulation and protection functions. Currently, common protective films need to be bonded with the battery pack bottom plate, water-cooling plate, upper cover, etc. using a structural adhesive with a bonding strength of 7 Mpa. This solution requires the bonding strength between the protective film and the battery cell aluminum shell to be greater than or equal to 7 Mpa. However, the commonly used structural adhesive for protective films is pressure-sensitive adhesive, and the bonding strength between the pressure-sensitive adhesive and the aluminum shell is about 2 Mpa, which often easily causes the bonding between the protective film and the aluminum shell to break, resulting in the separation of the protective film and the aluminum shell, and further leading to short circuits or other problems inside the battery. If a UV adhesive with a higher bonding strength is directly used for the protective film, the cost is likely to increase. In some other related technologies, windows are provided on the protective film, so that when the aluminum shell is bonded with the battery pack bottom plate, water-cooling plate, upper cover, etc., the structural adhesive is directly applied to the aluminum shell. However, in this solution, if the glue cannot completely cover the surface of the window, there will be a risk of insulation failure, leading to serious electrical safety accidents.

[0040] As Figures 1-8As shown, in the present application, by pasting a first protective film 21 with slightly poor bonding strength on the first sidewall 11 and a second protective film 22 with higher bonding strength on the second sidewall 12, after a plurality of battery cells 1 are stacked, most of the first sidewalls 11 are hidden between two adjacent battery cells 1, while substantially all of the second sidewalls 12 are exposed outside the plurality of stacked battery cells 1. And the second protective film 22 bonded on the second sidewall 12 has a higher bonding strength. Therefore, after the second protective film 22 is bonded to the battery pack bottom plate, the water-cooling plate, the upper cover, etc. through structural adhesive, the second protective film 22 is not easily separated from the housing, so that the insulation and protection functions can be stably realized. Moreover, for a single battery cell 1, in the present application, the second protective film 22 is only pasted on the second sidewall 12 with a smaller area, which can effectively reduce the cost.

[0041] Thus, for the battery 100 according to the embodiment of the present invention, by pasting a first protective film 21 with slightly poor bonding strength on the first sidewall 11 and a second protective film 22 with higher bonding strength on the second sidewall 12, not only can the battery 100 be better insulated and protected, but also the cost can be effectively reduced.

[0042] Exemplarily, the first adhesive layer is composed of pressure-sensitive adhesive. Pressure-sensitive adhesive, also known as Pressure Sensitive Adhesive (PSA for short), is a special type of adhesive. It can achieve instant bonding under slight pressure without heating, solvents or additional curing processes. The characteristics of pressure-sensitive adhesive are that it has good adhesiveness and elasticity at the same time, can quickly form a bond on different surfaces, and can be easily peeled off from the adherend without leaving residues or damaging the adherend surface. Thus, the first protective film 21 can be well pasted on the outer surface of the first sidewall 11. At the same time, the first protective film 21 can also be well peeled off from the outer surface of the first sidewall 11, and it is not easy to cause damage to the outer surface of the first sidewall 11 or leave residues on the outer surface of the first sidewall 11.

[0043] Exemplarily, the second adhesive layer is composed of UV glue. UV glue, also known as Ultraviolet Curing Adhesive, is an adhesive that can be quickly cured under ultraviolet irradiation. This glue is mainly composed of prepolymers, monomers, photoinitiators, additives, etc. Its working principle is based on a photochemical reaction. When the UV glue is exposed to ultraviolet light (mainly in the UV-A band, that is, 320 - 400 nanometers), the photoinitiator absorbs the ultraviolet energy and generates free radicals or cations, which then initiate the polymerization reaction between the monomers and prepolymers, causing the glue liquid to change from a liquid state to a solid state within a few seconds to a few minutes. The UV glue can make the second protective film 22 firmly pasted on the outer surface of the second sidewall 12.

[0044] In some embodiments of the present utility model, such as Figures 1-8 shown, the first protective film 21 has a first overlapping area 211, the second protective film 22 has a second overlapping area 221, and at least a part of the first overlapping area 211 and at least a part of the second overlapping area 221 are bonded to construct a composite area. By overlapping the first protective film 21 and the second protective film 22, the first protective film 21 and the second protective film 22 can be bonded to each other. Exemplarily, the first overlapping area 211 of the first protective film 21 is pasted on the outer side of the second overlapping area 221 of the second protective film 22. Thus, the first protective film 21 is not likely to affect the second protective film 22, that is, it is not likely to cause an impact on the second protective film 22 when the first protective film 21 is detached, and the second protective film 22 can be firmly pasted on the outer surface of the second side wall 12. Exemplarily, the second overlapping area 221 of the second protective film 22 is pasted on the outer side of the first overlapping area 211 of the first protective film 21. As Figures 1-8 shown, the first protective film 21 is respectively pasted on two first side walls 11 of the housing in the first direction, and the second protective film 22 is respectively pasted on two second side walls 12 of the housing in the second direction. In this way, by making the second overlapping area 221 of the second protective film 22 pasted on the outer side of the first overlapping area 211 of the first protective film 21, the second protective film 22 can be better pasted with the first protective film 21, and the risk of the first protective film 21 detaching from the outer surface of the first side wall 11 can be reduced, so that the first protective film 21 can be more firmly pasted on the outer surface of the first side wall 11.

[0045] In addition, the overlapping area can ensure that after absorbing the pasting tolerance, the first protective film 21 and the second protective film 22 can completely cover the outer surface of the housing, avoiding the occurrence of an area without the protective film 2 on the outer surface of the housing and resulting in insulation failure.

[0046] Optionally, as Figures 5-8 shown, the second protective film 22 extends to the outer surface of the first side wall 11 to construct a second overlapping area 221 overlapping with the first protective film 21 on the outer surface of the first side wall 11.

[0047] Exemplarily, the first overlapping area 211 of the first protective film 21 is pasted on the outer side of the second overlapping area 221 of the second protective film 22. Thus, the second overlapping area 221 of the second protective film 22 can be pasted on the outer surface of the first side wall 11, so as to increase the contact area between the second protective film 22 and the outer surface of the housing, and make the second protective film 22 more firmly pasted on the outer surface of the housing.

[0048] Exemplarily, the second overlapping area 221 of the second protective film 22 is pasted on the outer side of the first overlapping area 211 of the first protective film 21. Since the second protective film 22 extends to the outer surface of the first sidewall 11 and constructs the second overlapping area 221 overlapping with the first protective film 21 on the outer surface of the first sidewall 11, thus, while ensuring that the second sidewall 12 and the second protective film 22 have sufficient contact area, the second protective film 22 can also be well pasted with the first protective film 21, which can reduce the risk of the first protective film 21 detaching from the outer surface of the first sidewall 11, so that the first protective film 21 can be firmly pasted on the outer surface of the first sidewall 11.

[0049] In some embodiments of the present invention, there is an arc transition portion between the first sidewall 11 and the second sidewall 12. The second protective film 22 has a main body area 222 pasted on the second sidewall 12, an arc transition area 223 pasted on the outer surface of the arc transition portion, and a second overlapping area 221 pasted on the first sidewall 11. The second overlapping area 221 is located on the side of the arc transition area 223 away from the main body area 222. Thus, the second overlapping area 221 can be well pasted on the outer surface of the first sidewall 11, that is, the second protective film 22 can have a relatively sufficient contact area with the outer surface of the first sidewall 11.

[0050] In some embodiments of the present invention, as Figures 5-8 shown, in the direction from the first protective film 21 to the second protective film 22, the width H1 of the composite area is greater than or equal to 5 mm. By satisfying the above conditions, the first protective film 21 can be well bonded to the second protective film 22.

[0051] In some embodiments of the present invention, the thickness T1 of the second film layer and the thickness T2 of the second adhesive layer satisfy: 0.8 ≤ T1 / T2 ≤ 5. By satisfying the above conditions, the second adhesive layer can make the second film layer have a high bonding strength with the outer surface of the second sidewall 12. At the same time, the second film layer can also well insulate and protect the outer surface of the second sidewall 12.

[0052] Exemplarily, the thickness T1 of the second film layer satisfies: 40 um ≤ T1 ≤ 100 um.

[0053] Exemplarily, the thickness T2 of the second adhesive layer satisfies: 20 um ≤ T2 ≤ 50 um.

[0054] In some embodiments of the present invention, as Figures 1-4 shown, at least one second protective film 22 is provided on one side of the battery 100 in the second direction, and the second protective film 22 is pasted on the second sidewalls 12 of at least two battery cells 1.

[0055] Exemplarily, first protective films 21 may be pasted on two first side walls 11 of each battery cell 1. Then, a relatively large second protective film 22 may be pasted on second side walls 12 of two adjacent battery cells 1, that is, one second protective film 22 can be pasted on two second side walls 12 at the same time. Optionally, two ends of the second protective film 22 can respectively extend to two first side walls 11 of two battery cells 1 facing away from each other.

[0056] Exemplarily, as Figures 1-4 shown, first protective films 21 may be pasted on two first side walls 11 of each battery cell 1. Then, a relatively large second protective film 22 may be pasted on second side walls 12 of all battery cells 1, that is, the second protective film 22 can be pasted on second side walls 12 of all battery cells 1 on one side of the battery 100 in the second direction at the same time. And, in the first direction, two ends of the second protective film 22 respectively extend to first side walls 11 of two outermost battery cells 1 in the first direction.

[0057] It can be understood according to the above example that the second protective film 22 can also be pasted on three second side walls 12, four second side walls 12, five second side walls 12, etc. The present application does not make any restrictions.

[0058] In addition, for the above example, as Figures 1-4 shown, the second protective film 22 can be pasted on second side walls 12 of all battery cells 1 on one side of the battery 100 in the second direction at the same time. It should be noted that in the related art, after the conventional modules are stacked, they need to be lifted into the box by a vacuum chuck. This requires pasting a protective film on the upper surface of the module before the vacuum chuck lifting, so that the vacuum chuck can lift the module better and avoid air leakage gaps between the vacuum chuck and the module. After being put into the box, a whole protective film on the upper surface of the module is torn off and scrapped, resulting in serious material waste problems. In the present application, the second protective film 22 can be pasted on second side walls 12 of all battery cells 1 on one side of the battery 100 in the second direction at the same time, which can not only solve the problem of insufficient adhesion strength between the conventional protective film 2 and the aluminum shell of the battery cell, but also directly lift the battery 100 when it is put into the box, saving one conventional protective film 2.

[0059] Optionally, as Figures 1-4 shown, the first protective film 21 extends to the second side wall 12. Thus, when the second protective film 22 can be pasted on second side walls 12 of all battery cells 1 on one side of the battery 100 in the second direction at the same time, for each battery cell 1, the first protective film 21 and the second protective film 22 can better cover the first side wall 11, the second side wall 12 of each battery cell 1 and the intersection area between the first side wall 11 and the second side wall 12, so as to better insulate and protect the battery cell 1.

[0060] Exemplarily, a second protective film 22 can also be pasted on the lower surface of the battery 100, which can improve the pasting strength between the bottom cold plate or other structures and the battery 100. At the same time, it can also avoid the overflow of glue between the bottom battery cells 1, and improve the cycle life of the battery 100.

[0061] Optionally, the second protective film 22 is pasted on a plurality of second side walls 12, and in the first direction, both ends of the second protective film 22 extend to two first side walls 11 at both ends of the battery 100. Thereby, the pasting area of the second protective film 22 can be increased, and the pasting strength of the second protective film 22 can be improved.

[0062] In some embodiments of the present invention, the battery 100 includes a battery case, and a plurality of battery cells 1 and the protective film 2 are both installed in the battery case, and the battery case can effectively protect the plurality of battery cells 1 and the protective film 2.

[0063] The battery 100 according to the embodiments of the present invention and other components and operations of the battery are known to those of ordinary skill in the art, and will not be described in detail here.

[0064] In the description of this specification, the description with reference to terms such as "some embodiments", "optionally", "further", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery, characterized in that: include: A plurality of battery cells, wherein the plurality of battery cells are stacked along a first direction, a side wall of a shell of the battery cell in the first direction is a first side wall, and a side wall of the shell in a second direction is a second side wall, and the first direction and the second direction are perpendicular to each other; A protective film, the protective film is wrapped around the outer surface of the shell, the protective film includes a first protective film and a second protective film, the first protective film is attached to the outer surface of the first side wall, and the second protective film is attached to the outer surface of the second side wall, wherein, The first protective film includes a first film layer and a first adhesive layer, the second protective film includes a second film layer and a second adhesive layer, and the adhesive strength of the second adhesive layer is greater than that of the first adhesive layer.

2. The battery according to claim 1, characterized in that The first protective film has a first overlapping region, the second protective film has a second overlapping region, and at least a portion of the first overlapping region and at least a portion of the second overlapping region are bonded to construct a composite region.

3. The battery according to claim 2, characterized in that The second protection film extends to the outer surface of the first side wall to construct the second overlapping region overlapping with the first protection film on the outer surface of the first side wall.

4. The battery according to claim 3, characterized in that There is an arc transition portion between the first side wall and the second side wall, and the second protective film has a main body area pasted on the second side wall, an arc transition area pasted on the outer surface of the arc transition portion, and the second overlapping area pasted on the first side wall, and the second overlapping area is located on the side of the arc transition area away from the main body area.

5. The battery according to claim 2, characterized in that In the direction from the first protective film to the second protective film, a width H1 of the composite region is greater than or equal to 5 mm.

6. The battery according to claim 1, characterized in that The thickness T1 of the second film layer and the thickness T2 of the second adhesive layer satisfy: 0.8≤T1 / T2≤5.

7. The battery according to claim 1, characterized in that The battery is provided with at least one second protective film on one side of the second direction, and the second protective film is adhered to the second side walls of at least two of the battery cells, wherein the first protective film extends to the second side wall.

8. The battery according to claim 7, characterized in that The second protective film is adhered to the plurality of second side walls, and in the first direction, two ends of the second protective film extend to two first side walls at two ends of the battery respectively.

9. The battery according to claim 1, characterized in that The first adhesive layer is made of pressure-sensitive adhesive, and the second adhesive layer is made of UV adhesive.

10. The battery according to any one of claims 1 to 9, characterized in that The battery further includes a battery case, and the plurality of battery cells and the protection film are installed in the battery case.

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