Lithium battery end socket and lithium battery

Abstract

The lithium battery end socket comprises an end socket body, at least one containing space is arranged on the end socket body, the shape of the containing space is consistent with the shape of the cross section of the end socket body, a gap is formed between at least one side of the containing space and the edge of the end socket body, and at least one side of the containing space is communicated with the end socket body. An area formed by the gaps is a weak area opposite to the end socket body, and the containing space is filled with filling sheets. The through groove or the through hole is formed in the seal head body to form the accommodating space, the filling sheet is filled in the accommodating space, and the weak area is formed between the accommodating space and the seal head body, so that when the battery is short-circuited and emits heat, a large amount of gas is generated in the battery, the weak area is firstly broken, the gas pressure is released, and the battery is prevented from being damaged. And the temperature of the battery is released, so that high pressure and high temperature are not accumulated, fire and explosion are avoided, and the safety performance of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery manufacturing, and particularly relates to a lithium battery end cap and a lithium battery. Background Art

[0002] The lithium battery end cap refers to the top part used for encapsulating the lithium battery. Its main function is to protect the internal components of the battery and provide the sealing performance of the battery. It has the following main characteristics and functions: it plays a role in protecting the internal battery structure, electrolyte and electrodes, preventing the external environment from damaging the substances and structure inside the battery. The lithium battery end cap ensures that the electrolyte inside the battery does not leak through the tight connection with the battery housing, and at the same time prevents moisture or impurities in the external environment from entering the battery, maintaining the stability and safety of the battery.

[0003] With the increasing energy density of the battery, the current end cap structure is not sufficient to ensure the safety performance of the battery. Therefore, it is very important to improve the performance of the end cap structure while increasing the energy density of the battery, so as to ensure the safety performance of the battery. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome the above defects in the prior art, and provide a lithium battery end cap, which can reduce the explosion threshold of the internal pressure of the battery and improve the safety of the battery.

[0005] To achieve the above purpose, the utility model provides a lithium battery end cap, including: an end cap body, at least one accommodating space is arranged on the end cap body, the shape of the accommodating space is consistent with the cross-sectional shape of the end cap body, and a gap is formed between at least one side of the accommodating space and the edge of the end cap body. The area formed by the gap is the relatively weak area of the end cap body, and a filling sheet is filled in the accommodating space.

[0006] Further, the filling sheet is one or a combination of more than one of PTFE (polytetrafluoroethylene) sheet and PFA (tetrafluoroethylene copolymer) sheet. The melting points of PTFE and PFA are both between 260°-330°. When the battery generates heat, the temperature rise can first melt the filling sheet, making the accommodating space empty, which is beneficial for the high-temperature gas generated by the battery heating to break through the weak area, thereby playing a role in pressure relief and temperature reduction.

[0007] Further, the size of the gap is 1mm-3mm. Setting a 1-3mm gap makes the thickness of the weak area reasonable, which can ensure that the internal gas of the battery during heating can break through the weak area, avoiding the situation that the weak area is too thick and the gas cannot break through in time, resulting in too high internal temperature of the battery and explosion.

[0008] Further, a through groove is formed along the inner side of the head body, and the space formed by the through groove is the accommodating space. By providing the through groove to form the accommodating space, the production process is simple and the cost is reduced.

[0009] Further, the cross-sectional shape of the through groove is triangular, square, rectangular, polygonal, circular or other shapes. The setting of through grooves of these shapes can make the weak area easier to burst.

[0010] Further, the height of the through groove is 0.5 mm - 4 mm, and the width of the through groove is 1 mm - 5 mm. In this way, the optimal accommodating space can be achieved, the appropriate filling sheet can be filled more reasonably, and the thickness of the weak area can be guaranteed, which is beneficial to breaking through the weak area.

[0011] Further, the head body is provided with a through hole penetrating the head body, the inner space of the through hole is the accommodating space, gaps are formed between both sides of the through hole and both edges of the head body, and the area composed of the gaps is the weak area opposite to the head body. The adoption of the through through hole setting can reduce the requirements for the production process, is more convenient for filling the filling sheet, and furthermore, the overall weight of the head body can be reduced, thereby reducing the material cost. At the same time, the through hole can form two weak areas without sacrificing the structural strength, so that the heat generated by the battery can quickly break through the weak areas, thereby playing a role in pressure relief and temperature reduction.

[0012] Further, both the length and width of the through hole are 2 mm - 5 mm. By setting the length and width of the through hole, the size of the accommodating space can be limited to match the capacity of the filling sheet.

[0013] Further, an adhesive layer for bonding the filling sheet is provided on the inner wall of the through hole. The provision of the adhesive layer can better bond the filling sheet.

[0014] The present utility model also provides a lithium battery, including the above-mentioned lithium battery head.

[0015] Compared with the prior art, the present utility model has the following advantages: The present utility model forms an accommodating space by providing a through groove or a through hole in the head body, a filling sheet is filled in the accommodating space, and a weak area is formed between the accommodating space and the head body. The specific heat capacity and heat conduction ability of the filling sheet and the material of the head body are different. When heat-sealing with a head of this shape, the weakest weak area is formed between the accommodating space and the side edge of the head body. When the battery is short-circuited and generates heat, a large amount of gas is generated inside, and the rupture first occurs from this weak area, the gas pressure is released, and the temperature of the battery is also released, so that a large amount of pressure and high temperature will not accumulate, and it will not catch fire or explode, and the safety performance of the battery is improved. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of a lithium battery sealing head in Embodiment 1 of the present invention;

[0018] Figure 2 It is a partial structural schematic diagram of the cross-section of the through groove and the sealing head body;

[0019] Figure 3 It is Figure 2 Another perspective schematic diagram of the accommodating space in [[ ]] filled with the thin sheet;

[0020] Figure 4 It is a schematic structural diagram of a lithium battery sealing head in Embodiment 2 of the present invention;

[0021] Figure 5 It is Figure 4 A partial enlarged schematic diagram in [[ ]];

[0022] Figure 6 It is Figure 5 A schematic diagram of the filled thin sheet in [[ ]];

[0023] In the figure, there are included:

[0024] 1. Sealing head body; 11. Outer edge; 12. Inner edge; 2. Accommodating space; 3. Through groove; 31. Vertex edge; 4. Gap; 5. Weak area; 6. Battery; 7. Filling thin sheet; 8. Through hole; 81. Adhesive layer. Specific embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present embodiments. Obviously, the described embodiments are one embodiment of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, if the description of "first", "second", etc. is involved in the embodiments of the present utility model, the description of "first", "second", etc. is only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly specifying the quantity of the indicated technical features.

[0028] Embodiment 1

[0029] Please refer to Figures 1 to 3 , an embodiment of the present utility model provides a lithium battery sealing head, including: a sealing head body 1, and at least one accommodating space 2 is arranged on the sealing head body 1. In this embodiment, the accommodating space 2 is formed by a through groove 3 opened along the inner edge 12 of the sealing head body 1. Therefore, multiple groups of accommodating spaces 2 can be arranged by setting a plurality of through grooves 3 uniformly distributed on the sealing head body 1, so that a different density difference is formed between the accommodating space 2 and other areas of the sealing head body 1, and it is easier for the battery 6 to rush out from the position of the accommodating space 2 when it expands thermally; in addition, the number of the through grooves 3 can be set according to the type and material of the battery 6. For example, one through groove 3 is set in this embodiment, and the number is not limited one by one.

[0030] The shape of the above-mentioned through groove 3 is consistent with the cross-sectional shape of the sealing head body 1. For example Figure 1 as shown, the through groove 3 in this embodiment is a groove body with a triangular cross-section. Of course, other types of shapes of the through groove 3 can also be set, such as square, rectangular, polygonal, circular or other shapes, which can be adjusted according to actual needs.

[0031] To further ensure the safety performance of the battery 6, as Figure 2 shown, the open end of the through groove 3 is arranged on the inner edge 12 of the sealing head body 1, the apex edge 31 of the through groove 3 is far away from the inner edge 12, and a gap 4 is formed between the apex edge 31 and the outer edge 11 of the sealing head body 1. The area composed of the gap 4 is the relatively weak area 5 of the sealing head body 1. The size of the gap 4, that is, the distance between the apex edge 31 of the through groove 3 and the outer edge 11 of the sealing head is 1 mm. The size of the set spacing indirectly controls the thickness of the weak area 5. Therefore, the size can be considered according to the actual size of the battery 6 and the material of the battery 6, etc., and can be 1.5 mm, 2 mm, 2.5 mm or 3 mm, etc., as long as it is set in the range of 1-3 mm. The setting of the gap 4 of 1-3 mm makes the thickness of the weak area 5 reasonable, which can ensure that the internal gas of the battery 6 when heated can break through the weak area 5, and avoid the situation that the weak area 5 is too thick and the gas cannot break through in time, resulting in the explosion of the battery 6 due to too high internal temperature.

[0032] The accommodation space 2 is filled with a filling sheet 7, which is one or more combinations of PTFE (polytetrafluoroethylene) sheets and PFA (tetrafluoroethylene copolymer) sheets. After filling, the head body 1 is directly used in the normal production of the battery 6, so that the notch of the through groove 3 forms a heat-sealing layer for sealing. The melting points of PTFE and PFA used in the present utility model are both between 260° and 330°. By filling the filling sheet 7 in the accommodation space 2, especially the specific heat capacity and heat conduction ability of the filling sheet 7 are different from those of other parts of the head body 1, making the weak area 5 formed by the projection area of the accommodation space 2 easier to break, and the filling sheet 7 has a certain supporting rigidity, improving the internal supporting rigidity of the accommodation space 2. Under normal conditions, the head body 1 can maintain a good structure and is not easy to bend. When the battery 6 generates heat, the filling sheet 7 can be melted first, making the accommodation space 2 empty, which is conducive to the high-temperature gas generated by the battery 6 when it heats up to break through the weak area 5, thereby playing a role in pressure relief and temperature reduction.

[0033] It should be noted that the height of the above through groove 3 is 3.5 mm and the width is 1.5 mm. In some embodiments, the height of the through groove 3 can also be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, etc., as long as it is limited within the range of 0.5 mm - 4 mm. Similarly, the width of the through groove 3 can also be 1 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, as long as it is limited within the range of 1 mm - 5 mm. When selecting the height and width of the through groove 3, it depends on the size and material of the battery 6. As long as the through groove 3 and the outer edge 11 of the head body 1 leave a gap 4 to form the weak area 5. In this way, the optimal accommodation space 2 can be achieved, the appropriate filling sheet 7 can be filled more reasonably, and the thickness of the weak area 5 can be guaranteed, which is beneficial to breaking through the weak area 5.

[0034] Embodiment 2

[0035] The difference between this embodiment and Embodiment 1 is that this embodiment does not provide a through groove 3. As Figures 4 to 6 A through hole 8 penetrating the head body 1 is provided in the head body 1. The inner space formed by the inner wall of the through hole 8 is the accommodation space 2. In this embodiment, the through hole 8 is a square hole, that is, it can be a square hole with a square or rectangular cross-section or other square holes. Gaps 4 are formed between the two side edges of the through hole 8 and the two edges of the head body 1. The area composed of the gaps 4 is the weak area 5 opposite to the head body 1. The adoption of the through through hole 8 can reduce the requirements for the production process, is more convenient for filling the filling sheet 7, and can reduce the overall weight of the head body 1, thereby reducing the material cost. At the same time, the through hole 8 can form two weak areas 5 without sacrificing the structural strength, enabling the battery 6 to generate heat and quickly break through the weak areas 5, thereby playing a role in pressure relief and temperature reduction.

[0036] Since the through hole 8 of this embodiment is a through hole, in order to prevent the filling sheet 7 from falling off, an adhesive layer 81 for bonding the filling sheet 7 is provided on the inner wall of the through hole 8, and the adhesive layer 81 can be composed of a weakly adhesive material. In addition, the length and width of the through hole 8 in this embodiment are both 4 mm. In other embodiments, the size of the through hole 8 can be selected according to the size of the head. Generally speaking, the optimal size of the through hole 8 is between 2 mm and 5 mm. By setting the length and width of the through hole 8, the size of the accommodating space 2 can be defined to match the capacity of the filling sheet 7. Others are the same as in Embodiment 1, and the same technical effects as in Embodiment 1 are achieved.

[0037] The present utility model also provides a lithium battery, including the above-mentioned lithium battery head.

[0038] The present utility model forms an accommodating space 2 by providing a through groove 3 or a through hole 8 in the head body 1, fills the accommodating space 2 with a filling sheet 7, and forms a weak area 5 between the accommodating space 2 and the head body 1. The specific heat capacity and heat conduction ability of the filling sheet 7 and the material of the head body 1 of the present utility model are different. When heat-sealing with a head of this shape, the weakest weak area 5 is formed between the accommodating space 2 and the side edge of the head body 1. When the battery 6 undergoes a safety test, a large amount of gas is generated inside, and the rupture first occurs at this weak area 5, the gas pressure is released, and the temperature of the battery 6 is also released, without accumulating a large pressure and a high temperature, and without catching fire or exploding, thus improving the safety performance of the battery 6.

[0039] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A lithium battery sealing head, comprising: a sealing head body (1), characterized in that, At least one accommodating space (2) is provided on the head body (1). The shape of the accommodating space (2) is consistent with the cross-sectional shape of the head body (1), and a gap (4) is formed between at least one side of the accommodating space (2) and the edge of the head body (1). The area composed of the gaps (4) is the relatively weak area (5) of the head body (1). A filling sheet (7) is filled in the accommodating space (2).

2. The lithium battery head seal according to claim 1, characterized in that The filling sheet (7) is one or a combination of PTFE sheets and PFA sheets.

3. The lithium battery head seal according to claim 1, characterized in that, The size of the gap (4) is 1 mm - 3 mm.

4. The lithium battery head seal according to claim 1, characterized in that, A through groove (3) is formed along the inner edge (12) of the head body (1), and the space formed by the through groove (3) is the accommodating space (2).

5. The lithium battery head seal according to claim 4, wherein, The cross-sectional shape of the through groove (3) is triangular, square, rectangular, polygonal, or circular.

6. The lithium battery head seal according to claim 4, wherein, The height of the through groove (3) is 0.5 mm - 4 mm, and the width of the through groove (3) is 1 mm - 5 mm.

7. The lithium battery end cap according to claim 1, wherein The head body (1) is provided with a through hole (8) penetrating through the head body (1). The internal space of the through hole (8) is the accommodating space (2). Gaps (4) are formed between both sides of the through hole (8) and both edges of the head body (1). The area composed of the gaps (4) is the relatively weak area (5) of the head body (1).

8. The lithium battery end cap according to claim 7, characterized in that, The length and width of the through hole (8) are both 2 mm - 5 mm.

9. The lithium battery end cap according to claim 7, wherein, An adhesive layer (81) for bonding the filling sheet (7) is provided on the inner wall of the through hole (8).

10. A lithium battery, characterized in that, Including the lithium battery head described in any one of claims 1 - 9.

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