Insulating film, battery cell assembly and battery

Abstract

The utility model relates to the field of batteries, in particular to an insulating film, a battery cell assembly and a battery, and aims to solve the problem of dimensional deviation when an existing insulating film is bent to wrap a battery cell. In order to achieve the purpose, the insulating film comprises a bending area, the bending area extends along a first direction, the bending area is provided with a plurality of through holes, and the plurality of through holes are arranged at intervals along the first direction. Under the condition of adopting the technical scheme, the bending area and the through holes can absorb the size deviation caused by the bending of the film body, so that the problem of influence on the safety of the battery caused by the size deviation is avoided.

Description

Technical Field

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

[0002] At present, the automobile industry is facing huge challenges in energy and environment. Therefore, new energy vehicles with high energy utilization and less environmental pollution have become the main development direction of the automobile industry in the future. Among them, batteries, as the core components of new energy vehicles, affect the performance of the entire vehicle, thus putting forward more stringent requirements on the performance of batteries. Batteries mainly include shells, insulating films and bare cells. Among them, bare cells need to be placed in the shell under the wrapping of the insulating film.

[0003] However, the insulating film is usually a planar structure. When it needs to be bent to wrap the bare battery cell, the insulating film may produce certain shape or size deviations due to the bending. For example, local bulges / wrinkles often appear at the bending position. The appearance of local bulges / wrinkles will produce a certain amount of deviation at the bending position, which may affect the dimensional consistency of the battery cell. In more extreme cases, it may even cause partial damage to the insulating film, which will affect the safety performance of the battery.

[0004] Accordingly, this field requires a new technical solution to solve the above problems to a certain extent. Utility Model Content

[0005] The utility model aims to solve the above technical problems to a certain extent, that is, to solve the problem that the existing insulating film will have dimensional deviation when wrapping the battery core.

[0006] In a first aspect, the utility model provides an insulating film, which includes a bending area, the bending area extends along a first direction, the bending area is provided with a plurality of through holes, and the plurality of through holes are arranged at intervals along the first direction.

[0007] In the case of adopting the above technical solution, when the insulating film is bent and positioned along the bending area to wrap the battery cell, the bending area and its through holes can eliminate part of the dimensional deviation caused by the accumulation of the insulating film, thereby effectively avoiding the phenomenon of local bulges / wrinkles caused by the accumulation of the film body. Specifically, the appearance of local bulges / wrinkles may affect the dimensional consistency of the battery cell and the insulating film. In more extreme cases, it may cause local stress concentration, resulting in local lithium deposition of the bare battery cell and even local damage to the insulating film when the vehicle is in extreme operating conditions for a long time, which will affect the safety performance of the battery.

[0008] It is understandable that those skilled in the art can determine the specific structural form of the bending area according to actual needs, such as the bending area can be an indentation set by pre-pressing, the corresponding position of the insulating film is thinned, a part of the structure is removed at the corresponding position of the insulating film, etc. For example, the long strip holes and the thinning treatment are arranged at intervals. By setting the through holes, the bending guiding performance of the bending area can be further guaranteed.

[0009] It is understandable that those skilled in the art can flexibly adjust the structure (size, shape), quantity and distribution of the through holes in the bending area according to actual needs. For example, the through holes can be round holes, elongated holes or special-shaped holes, etc., the structures of the multiple through holes can be the same or different, the multiple through holes can be distributed in a partial area or the entire area of ​​the bending area, and the multiple through holes can be evenly or unevenly distributed in the bending area.

[0010] It is understandable that those skilled in the art can determine the first direction of the bending area according to actual bending requirements. For example, the first direction can be a direction extending along a straight line, a combination of straight lines, a curve, or the like along which the insulating film needs to be bent.

[0011] For the above insulating film, in a possible implementation manner, the bending region extends in a linear shape along the first direction.

[0012] Through such a configuration, a possible structural form of the bending region is provided, such as a linear structure extending along the length / width direction of the battery cell.

[0013] For the above-mentioned insulating film, in a possible implementation manner, a plurality of the bending regions are arranged in parallel.

[0014] Through such a structure, a specific relative position of the multiple bending regions constituting the insulating film is given.

[0015] For the above insulating film, in a possible implementation manner, the bending regions include four, and the four bending regions are arranged at intervals along the second direction.

[0016] Through such a configuration, a specific layout method of multiple bending regions constituting an insulating film is provided.

[0017] For the above-mentioned insulating film, in a possible implementation manner, in the second direction, the first end of the insulating film is fixedly connected to the second end of the insulating film.

[0018] Through such a configuration, the space structure of the insulating film when the battery cell is wrapped is given. For example, the second direction should have a certain angle with the first direction. For example, the first direction is the length direction of the battery cell, and the second direction is approximately perpendicular to the first direction.

[0019] For the above insulating film, in a possible implementation manner, a size of the through hole in the second direction is H, wherein 0<H≤1 mm.

[0020] For the above insulating film, in a possible implementation manner, a size of the through hole in the first direction is W, wherein 1≤W / H≤10; and / or an interval between adjacent through holes is D, wherein 1≤D / H≤10.

[0021] Such a configuration provides a possible size range of the through holes and a distribution pattern of the through holes in the bending region.

[0022] For the above-mentioned insulating film, in a possible implementation manner, in the first direction, a groove is provided at the first end of the insulating film.

[0023] In a second aspect, the utility model provides a battery cell assembly, which includes a battery cell and the insulating film as described in any one of the above items, wherein the insulating film is coated on the outer surface of the battery cell.

[0024] It can be understood that the battery cell assembly has all the technical effects of the insulating film described in any of the above items, which will not be repeated here.

[0025] In a third aspect, the utility model provides a battery, which includes a shell and the aforementioned battery cell assembly, wherein the battery cell assembly is accommodated in the shell.

[0026] It can be understood that the battery has all the technical effects of the battery cell assembly described in any of the above items, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0028] Figure 1 An exploded schematic diagram of a battery according to an embodiment of the utility model is shown;

[0029] Figure 2 An exploded schematic diagram showing a battery cell assembly according to an embodiment of the utility model;

[0030] Figure 3 A schematic diagram showing a planar expansion of an insulating film in a battery cell assembly according to an embodiment of the utility model;

[0031] Figure 4 for Figure 3 A magnified schematic diagram of part A in the figure.

[0032] Reference numerals list

[0033] 1.Battery;

[0034] 11. first shell; 12. second shell; 13. partition;

[0035] 14. first battery cell; 141. bare battery cell; 142. bracket; 143. side panel;

[0036] 15. Second battery cell;

[0037] 2. Insulation film;

[0038] 21. First bending area;

[0039] 22. second bending region; 221. through hole;

[0040] 23. The third bending region; 24. The fourth bending region;

[0041] 25. Groove. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. For example, although the present embodiment is introduced in conjunction with the first battery cell, this is not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art may apply the present invention to the second battery cell, etc.

[0043] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" 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 direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] As the core component of the vehicle, the battery provides the main power source for the vehicle. Common batteries include lead-acid batteries, nickel-metal hydride batteries, lithium-ion batteries, etc. Taking lithium-ion batteries as an example, they have the advantages of high energy, high power and high energy density, can be recycled at a high rate of partial charge, and can be used normally in the range of -30℃ to 95℃, so the operating temperature range is relatively wide.

[0046] The lithium-ion battery includes a shell and a cell assembly encapsulated in the shell, wherein the cell assembly mainly includes an insulating film and a bare cell wrapped in the insulating film. The bare cell is wrapped by bending the insulating film and placed in the shell together to ensure that the bare cell is safely placed in the shell. At the same time, since the insulating film has insulating properties, it can isolate the bare cell from other metal parts such as the shell. For example, the bare cell mainly includes a positive electrode sheet, a negative electrode sheet and a diaphragm, and the positive electrode sheet and the negative electrode sheet are respectively provided with a positive electrode ear and a negative electrode ear, and the positive electrode ear and the negative electrode ear are respectively connected to the positive electrode column and the negative electrode column. The positive / negative electrode ear can be directly connected to the pole corresponding to the polarity and position through a transfer structure (such as a transfer structure is usually a transfer sheet, and the transfer sheet can include but is not limited to a sheet structure made of a copper sheet, an aluminum sheet or other conductive materials) (such as a connection method including but not limited to ultrasonic welding, laser welding, and riveting). Among them, the negative electrode of the lithium-ion battery is metallic lithium, and the positive electrode is MnO2.

[0047] See first Figure 1 and Figure 2 , Figure 1 An exploded schematic diagram of a battery according to an embodiment of the utility model is shown. Figure 2 The exploded schematic diagram of a battery cell assembly according to an embodiment of the utility model is shown. Figure 1 and Figure 2 As shown, in a possible embodiment, the battery cell assembly 1 mainly includes a shell, a battery cell and a partition 13, wherein the shell includes a first shell 11 and a second shell 12, the first and second shells respectively cooperate with the partition 13 to form two independent placement spaces inside, and the battery cell includes a first battery cell 14 and a second battery cell 15, and the first battery cell 14 and the second battery cell 15 are respectively placed in the two placement spaces.

[0048] Taking the first battery cell 14 as an example, the first battery cell mainly includes a bare battery cell 141, a bracket, a side plate, and an insulating film 2 with an accommodation space. Specifically, two brackets 142 are respectively arranged at both ends of the bare battery cell 141, and the side plate 143 is arranged at a position in the thickness direction of the bare battery cell 141 where no bracket is arranged. The above structures can protect the bare battery cell.

[0049] See also Figure 3 and Figure 4 , Figure 3A schematic diagram showing a planar expansion of an insulating film 2 in a battery cell assembly according to an embodiment of the utility model is shown. Figure 4 for Figure 3 The enlarged schematic diagram of the local A in FIG. Figure 3 and Figure 4 As shown, according to Figure 3 In the direction shown, the insulating film 2 is provided with four parallel bending areas with roughly the same structure from top to bottom (respectively recorded as the first bending area 21, the second bending area 22, the third bending area 23 and the fourth bending area 24), and the insulating film 2 is bent along the bending area to form a accommodating space for the bare battery cell 141. After bending, the portion of the insulating film 2 above the first bending area 21 and the portion of the insulating film 2 below the fourth bending area 24 can be fixedly connected by methods such as gluing.

[0050] Furthermore, a plurality of grooves 25 are provided at both ends of the insulating film 2 in the first direction, and in the first direction, the first end of the insulating film 2 is any one of its two ends. Since the end surface of the bracket 142 away from the bare battery cell 141 is provided with a receiving groove (not shown) for receiving the pole, the two ends of the insulating film 2 in the first direction are fixedly connected to the bracket 142, and the grooves on the insulating film 2 are connected to the receiving grooves, thereby preventing the end of the insulating film 2 from interfering with the pole, simplifying the structure, and reducing the cost, while facilitating improving the space utilization and energy density of the battery.

[0051] The following description will be made by taking the second bending area 22 as an example. Figure 4 In a possible embodiment, the second bending area 22 extends into a linear structure, and a plurality of through holes 221 are arranged at intervals on the second bending area. In this example, the structures of the through holes are substantially the same and are all bar holes. The plurality of bar holes are evenly distributed in each bending area, that is, the intervals between adjacent bar holes are substantially the same.

[0052] The length of the through hole is recorded as W, the width is recorded as H, and the interval between adjacent strip holes is D. In a possible implementation, 0<H≤1mm, 1≤W / H≤10, 1≤D / H≤10.

[0053] By limiting H to the range of 0<H≤1mm, on the one hand, the width of the through hole 221 can be limited to a smaller range to ensure the insulation effect of the insulating film 2, and on the other hand, it can prevent the width of the through hole 221 from being too large to affect the insulation effect of the insulating film 2, and can prevent the bending effect of the insulating film 2 from being affected. The setting of the above range can ensure the insulation effect of the insulating film 2 on the one hand, and the bending effect of the insulating film 2 on the other hand.

[0054] The ratio of the length W of the through hole to the width H of the through hole is limited to the following range: 1≤W / H≤10. On the one hand, it can prevent the length of the through hole 221 from being too small to affect the bending effect of the insulating film 2, making it unable to be bent smoothly and effectively. On the other hand, it can prevent the length of the through hole 221 from being too large to cause poor insulation effect of the insulating film 2. The setting of the above range can ensure the insulation effect of the insulating film 2 on the one hand, and the bending effect of the insulating film 2 on the other hand.

[0055] The ratio range of the interval D between the through holes 221 to the width H of the through holes is limited to the following range: 1≤D / H≤10, which can prevent the spacing between the through holes 221 from being too small, which makes the manufacturing difficult, and can prevent the spacing between the through holes 221 from being too large, which makes it difficult for the insulating film 2 to bend around the bending area, thereby affecting the bending effect of the insulating film 2. The above range can ensure the insulation and bending effects, and can reduce the manufacturing difficulty and improve the manufacturing efficiency.

[0056] In an alternative embodiment, the structure of the through hole and the arrangement of the through hole in the bending area can be flexibly adjusted. Different bending areas and the arrangement of the through holes thereon can be the same or different. For example, the first bending area provided with the through hole is roughly a dotted line structure, and the second bending area provided with the through hole is roughly a dotted line structure.

[0057] In an alternative embodiment, the combination of the four bending regions is not limited, and those skilled in the art can flexibly select the structural form, length / width, number of bending regions, and extension direction of each bending region according to actual needs. For example, those skilled in the art can also add one or more bending regions at positions close to existing bending regions or at other positions that need to be bent.

[0058] It can be seen that in the battery cell assembly of the present invention, the bending area on the insulating film can eliminate part of the deviation caused by the film stacking of the insulating film, and the through hole in the bending area realizes the dimensional tolerance of the bending area, which effectively suppresses the problem of decreased consistency of the battery cell caused by the deviation.

[0059] It should be noted that the above preferred embodiments are only used to illustrate the principle of the utility model and are not intended to limit the scope of protection of the utility model. Without departing from the principle of the utility model, those skilled in the art may adjust the above-mentioned setting method so that the utility model can be applied to more specific application scenarios. For example, although the present embodiment is introduced in conjunction with the battery cell assembly and battery of an electric vehicle, this is not intended to limit the scope of protection of the utility model. Without departing from the principle of the utility model, those skilled in the art may apply the utility model to vehicles such as electric trains.

[0060] Of course, the above-mentioned replaceable implementations, as well as the replaceable implementations and the preferred implementations, can be used in a cross-coordinated manner to combine new implementations to suit more specific application scenarios.

[0061] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments, such as the structure of the through hole and the structure of the bending area. In the claims of the present invention, any one of the claimed embodiments may be used in any combination.

[0062] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An insulating film, characterized in that: The insulating film comprises a bending region, the bending region extends along a first direction, a plurality of through holes are arranged in the bending region, and the plurality of through holes are arranged at intervals along the first direction.

2. The insulating film according to claim 1, wherein The bending area extends along the first direction to form a linear structure.

3. The insulating film according to claim 2, characterized in that The plurality of bending regions are arranged in parallel.

4. The insulating film according to claim 3, characterized in that The bending regions include four, and the four bending regions are arranged at intervals along the second direction.

5. The insulating film according to claim 4, characterized in that In the second direction, the first end of the insulating film is fixedly connected to the second end of the insulating film.

6. The insulating film according to claim 4, characterized in that The size of the through hole in the second direction is H, wherein 0<H≤1mm.

7. The insulating film according to claim 6, characterized in that The through hole has a size W in the first direction, wherein 1≤W / H≤10; and / or The interval between adjacent through holes is D, wherein 1≤D / H≤10.

8. The insulating film according to claim 1, wherein In the first direction, a first end of the insulating film is provided with a groove.

9. A battery cell assembly, characterized in that: The battery cell assembly comprises a battery cell and an insulating film according to any one of claims 1 to 8, wherein the insulating film is coated on the outer surface of the battery cell.

10. A battery, characterized in that: The battery comprises a shell and the battery cell assembly as claimed in claim 9, wherein the battery cell assembly is accommodated in the shell.

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