Battery cell and power device

Abstract

Battery cell characterized in that it comprises a housing and an explosion-proof valve; wherein the housing comprises a plurality of side walls, the plurality of side walls forming a cylindrical structure; wherein the explosion-proof valve is mounted on one of the side walls, wherein the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to the thickness of the other side walls, and the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to a predetermined thickness to produce a deformation under a predetermined pressure and furthermore to produce an opening force on the explosion-proof valve.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] The present application claims priority over Chinese patent application No. 202321674898.1, filed with the Chinese Patent Office on June 28, 2023, entitled “Battery Cell and Power Device”, the entire contents of which are incorporated into this document by reference. AREA OF TECHNOLOGY

[0002] The present application relates to the field of lithium-ion batteries and in particular to a battery cell and a power device. BACKGROUND

[0003] A pressure relief mechanism in a lithium-ion battery plays a crucial role in its safety. For example, if a short circuit, overcharging, or other issue occurs, a thermal runaway can occur within the battery, leading to a rise in internal pressure. At this point, the pressure relief mechanism must release this pressure to the outside, preventing the battery from exploding.

[0004] A lithium-ion battery cell casing comprises numerous sidewalls, with a pressure relief mechanism mounted on one of these. These sidewalls are all of uniform thickness and relatively thick. This not only increases the cell's weight but also reduces the effective internal space, resulting in poor utilization of the internal volume and a lower energy density. SUMMARY

[0005] One objective of the present application is to provide a battery cell and a power device that can reduce the weight of a housing and are advantageous for opening an explosion-proof valve.

[0006] The present application provides a battery cell that includes a housing and an explosion-proof valve; wherein the housing includes a plurality of side walls, the plurality of side walls forming a cylindrical structure; wherein the explosion-proof valve is mounted on one of the side walls, wherein the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to the thickness of the other side walls, and the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to a predetermined thickness to produce a deformation under a predetermined pressure and furthermore to produce an opening force on the explosion-proof valve.

[0007] In the above technical solution, the side wall on which the explosion-proof valve is mounted is a first wall, wherein the thickness of the first wall is d1 and where d1 ≤ 0.6 mm; where the remaining side walls are second walls, a thickness of the second walls is d2 and 0 mm ≤ d2-d1 ≤ 2 mm.

[0008] In the above technical solution, the thickness of the explosion-proof valve is e and is 0.2 < e / d1 ≤ 1.

[0009] In the above technical solution, the cylindrical structure is also a rectangular cylindrical / prismatic structure; where the number of first walls is one, the number of second walls is three, and where an area of ​​an outer surface of the first wall is less than or equal to an area of ​​an outer surface of the second wall connected to the first wall.

[0010] In the above technical solution, a longitudinal direction of an edge connecting the first wall and the second wall is also a longitudinal direction of the first wall and a longitudinal direction of the explosion-proof valve is the same as the longitudinal direction of the first wall; wherein in the longitudinal direction of the first wall there is a distance s1 between an edge of the explosion-proof valve and an edge of the first wall and wherein s1 ≥ 3.5 mm; and / or wherein in a width direction of the first wall there is a distance s2 between an edge of the explosion-proof valve and an edge of the first wall and wherein s2 ≥ 10 mm.

[0011] In the above technical solution, the length of the explosion-proof valve L is further defined, where the width of the explosion-proof valve is B, and where 1 ≤ L / B ≤ 5.

[0012] In the above technical solution, the housing further includes a positive cover plate and a negative cover plate, and the positive cover plate and the negative cover plate are each mounted at openings at two ends of the cylindrical structure to enclose and form a receiving chamber for receiving a raw cell.

[0013] In the above technical solution, the battery cell can also include a support plate; wherein the support plate is provided between the side wall on which the explosion-proof valve is mounted and the raw cell, and the support plate is formed with a channel.

[0014] In the above technical solution, the battery cell also includes an insulating protective film; wherein the insulating protective film encloses side sections of the raw cell and the support plate is enclosed within the insulating protective film.

[0015] The present application further provides a power device incorporating the battery cell, in accordance with the solutions above.

[0016] Compared to the prior art, the following are advantageous effects of the present application: In the battery cell provided by the present application, the thickness of a side wall on which an explosion-proof valve is mounted is set to be less than or equal to the thickness of the other side walls; on the one hand, the weight of a housing can be further reduced, and on the other hand, the side wall can be easily deformed to generate a tensile force on the explosion-proof valve, which has a positive effect on the rapid opening of the explosion-proof valve.

[0017] The present application further provides a power device incorporating the battery cell, according to the solutions described above. Based on the analysis above, the power device also exhibits the aforementioned advantageous effects, which are not described in detail in this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions in specific embodiments of the present application or the prior art, the drawings necessary to describe these specific embodiments or the prior art are briefly presented below. It is clear that the drawings in the following description represent some embodiments of the present application and that other drawings can be obtained by a person skilled in the art without any creative effort based on these drawings. Fig. Figure 1 is a schematic drawing of an extensional force of a side wall according to the present application; Fig. Figure 2 is a structural schematic drawing of a cylindrical structure according to the present application; Fig. 3 is a first structural schematic drawing of a battery cell according to the present application; and Fig. Figure 4 is a second structural schematic drawing of a battery cell according to the present application.

[0019] In the figures: 101 - housing; 102 - explosion-proof valve; 103 - mounting hole; 104 - fracture line; 105 - first wall; 106 - second wall; 107 - positive cover plate; 108 - negative cover plate; 109 - support plate; 110 - insulating protective film. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0020] The technical solutions of the present application are described clearly and completely below with reference to the drawings. It is clear that the described embodiments are part of the embodiments of the present application, but not all of them. Based on the embodiments in the present application, all other embodiments that a person skilled in the art can make without creative effort are within the scope of protection of the present application.

[0021] It should be noted that in the description of the present application, the orientations or positional relationships indicated by the terms "central", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on the orientations or positional relationships shown in the drawings and serve only to describe the present application and to simplify the description, rather than indicating or implying that a device or element in question must have a specific orientation, be constructed and operated in a specific orientation, and should therefore not be interpreted as restricting the present application. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be interpreted as indicating or implying any relative importance.

[0022] It should be noted that, unless otherwise specified and limited, the terms "assemble", "connect", and "connection" in the description of this application are to be understood in a broad sense. For example, the terms may refer to a permanent connection, a detachable connection, or an integral connection; the terms may refer to a mechanical connection or an electrical connection; the terms may refer to a direct connection or an indirect connection through an intermediate medium or an internal connection between two elements. The specific meaning of the aforementioned terms in this application may be understood by the person skilled in the art according to the specific situations. Design 1

[0023] A battery cell provided by the present application comprises a housing 101 and at least one explosion-proof valve 102 mounted on the housing 101. If the internal pressure of a battery structure increases to a certain level, internal electrolyte or other substances can be released by opening the explosion-proof valve 102, thereby reducing the internal pressure of the battery structure to prevent a battery explosion.

[0024] As in the Fig. As shown in Figures 1 to 4, the housing 101 specifically comprises a plurality of side walls, which form a cylindrical structure designed to encase the side sections of a battery cell blank, thus providing protection to the blank. One of the side walls is formed with a mounting bore 103, and the explosion-proof valve 102 can be welded and mounted in this bore 103 to secure and fasten the valve. The thickness of the side wall to which the explosion-proof valve 102 is mounted is less than or equal to the thickness of the other side walls and thus reduces the weight of the housing 101.Furthermore, the thickness of the side wall on which the explosion-proof valve 102 is mounted is less than or equal to a predetermined thickness to allow the side wall to deform under a predetermined pressure in order to generate an opening force on the explosion-proof valve 102.

[0025] Specifically, if the internal pressure of the raw cell provided within the housing 101 is high and exceeds a threshold value of the explosion-proof valve 102, because the thickness of the side wall on which the explosion-proof valve 102 is mounted is thinner, the side wall is more likely to expand outwards and become bulged. A lateral force generated by the deformation of the side wall (a force F1, as in Fig. 1 shown), generates a lateral tensile force on a fracture line 104 of the explosion-proof valve 102 (a force F2, as shown in Fig. 1 shown). That is, in addition to being subject to a vertical pressure generated by an internal airflow (a force F3, as in Fig. (as shown in Figure 1), the explosion-proof valve 102 is also subject to a tensile force with a “tearing” effect due to the deformation of the side walls in four circumferential directions, in order to enable the explosion-proof valve 102 to be opened quickly and to reduce pressure in the internal raw cell in a timely manner.

[0026] In the battery cell provided by the present application, by adjusting the thickness of the side wall on which the explosion-proof valve 102 is mounted to be less than or equal to the thickness of the other side walls, the weight of the housing 101 can be further reduced, and the side wall can be easily deformed to generate a tensile force on the explosion-proof valve 102, which has a positive effect on a rapid opening of the explosion-proof valve 102.

[0027] In an optional solution of this embodiment, the side wall on which the explosion-proof valve 102 is mounted is a first wall 105, the thickness of the first wall 105 being d1, where d1 ≤ 0.6 mm; the remaining side walls are second walls 106, the thickness of the second walls 106 being d2, where 0 mm ≤ d2-d1 ≤ 2 mm. The first wall 105 and the second walls 106 have relatively thin thicknesses and can reduce the weight of the housing 101.

[0028] Furthermore, the thickness of the explosion-proof valve is e, and where 0.2 < e / d1 ≤ 1. The thickness of the explosion-proof valve 102 and the thickness of the first wall 105 have the above relationship such that when the internal pressure of the raw cell exceeds the threshold of the explosion-proof valve 102, the first wall 105 can produce a corresponding deformation to simultaneously generate a force to open the explosion-proof valve 102, enabling the explosion-proof valve 102 to open quickly.

[0029] In an optional solution of this embodiment, the cylindrical structure is a rectangular cylindrical structure, the number of first walls 105 is one, and the number of second walls 106 is three. One of the second walls 106 has the same shape as the first wall 105 and is positioned opposite the first wall 105, and two of the second walls 106 are connected to the first wall 105. The area of ​​an outer surface of the first wall 105 is less than or equal to the area of ​​an outer surface of the second wall 106 that is connected to the first wall 105.

[0030] In this embodiment, as in Fig. As shown in Figure 2, the cylindrical structure is specifically a rectangular cylindrical structure with a rectangular cross-sectional profile. The side wall on which the explosion-proof valve 102 is mounted is the first wall 105, which has a smaller plate area. As the internal pressure of the raw cell increases, the first wall 105 will experience a higher degree of deformation and is more likely to generate a tensile force with a "tension" effect.

[0031] Specifically, as in Fig. Figure 2 shows that a longitudinal direction of an edge connecting the first wall 105 and the second wall 106, a longitudinal direction of the first wall 105, two explosion-proof valves 102 are spaced apart along the longitudinal direction of the first wall 105, and a longitudinal direction of the two explosion-proof valves 102 is equal to the longitudinal direction of the first wall 105. Specifically, a length of the explosion-proof valve is L, a width of the explosion-proof valve 102 is B, and where 1 ≤ L / B ≤ 5.

[0032] If necessary, in the longitudinal direction of the first wall 105, a distance s1 is provided between an edge of the explosion-proof valve 102 and an edge of the first wall 105, where s1 ≥ 3.5 mm; in a transverse direction of the first wall 105, a distance s2 is provided between an edge of the explosion-proof valve 102 and an edge of the first wall 105, where s2 ≥ 10 mm, so that a stable connection between the explosion-proof valve 102 and the first wall 105 can be ensured, in order to enable the explosion-proof valve 102 to be reliably mounted on the first wall 105. Design 2

[0033] The battery cell in this embodiment 2 is an improvement based on the preceding embodiment. The technical content disclosed in the preceding embodiment is not described again, and the content disclosed in the preceding embodiment is also part of the content disclosed in this embodiment 2.

[0034] As in the Fig. 3 and Fig.As shown in Figure 4, in an optional solution of this embodiment, the housing 101 further includes a positive cover plate 107 and a negative cover plate 108. The positive cover plate 107 and the negative cover plate 108 are each mounted at openings at two ends of the cylindrical structure to enclose and form a receiving chamber for receiving a raw cell. The positive cover plate 107 and the negative cover plate 108 are both electrically connected to the raw cell to establish an electrical connection between the raw cell and other external electrical components.

[0035] In an optional solution of this embodiment, when the battery cell is arranged as intended, the side wall on which the explosion-proof valve 102 is mounted faces downwards. A support plate 109 is provided between the side wall on which the explosion-proof valve 102 is mounted and the battery cell. The support plate 109 supports the battery cell and prevents it from pressing tightly against the first wall 105, which would interfere with the opening of the explosion-proof valve 102. Furthermore, the support plate 109 has a channel so that internal electrolyte or other substances can be drained successively from the channel and the explosion-proof valve 102.

[0036] In an optional solution of this embodiment, the battery cell further includes an insulating protective film 110; the insulating protective film 110 encloses side sections of the raw cell, and the support plate 109 is enclosed within the insulating protective film 110. The insulating protective film 110 can improve the insulating performance of the battery cell and prevent a short circuit. embodiment 3

[0037] Embodiment 3 of the present application provides a power device that includes the battery cell according to one of the preceding embodiments. Therefore, the power device exhibits all the advantageous technical effects of the battery cell according to one of the preceding embodiments, which are not described in detail in this document.

[0038] Finally, it should be noted that the foregoing embodiments are used only to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art understands that they may still modify the technical solutions described in the aforementioned embodiments or substitute some or all of the technical features therein. However, such modifications or substitutions do not alter the core of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.Furthermore, the person skilled in the art can understand that, although some embodiments in this document contain certain features which are included in other embodiments but do not include other features, combinations of features from different embodiments lie within the scope of the present application and constitute different embodiments. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 202321674898.1

[0001]

Claims

[1] Battery cell, characterized by that it includes a housing and an explosion-proof valve; wherein the housing comprises a plurality of side walls, the plurality of side walls forming a cylindrical structure; wherein the explosion-proof valve is mounted on one of the side walls, wherein the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to the thickness of the other side walls, and the thickness of the side wall on which the explosion-proof valve is mounted is less than or equal to a predetermined thickness to produce a deformation under a predetermined pressure and furthermore to produce an opening force on the explosion-proof valve. [2] Battery cell according to claim 1, characterized by that the side wall, on where the explosion-proof valve is mounted, there is a first wall, a thickness of the first wall d1, and d1 ≤ 0.6 mm; the remaining side walls are second walls, a thickness of the second walls is d2 and 0 mm ≤ d2-d1 ≤ 2 mm. [3] Battery cell according to claim 2, characterized by , that the thickness of the explosion-proof valve is e and 0.2 < e / d1 ≤ 1. [4] Battery cell according to claim 2, characterized by , that the cylindrical structure is a rectangular cylindrical structure; where the number of first walls is one, the number of second walls is three, and the area of ​​an outer surface of the first wall is less than or equal to the area of ​​an outer surface of a second wall connected to the first wall. [5] Battery cell according to claim 4, characterized by , that a longitudinal direction of an edge connecting the first wall and the second wall is a longitudinal direction of the first wall and a longitudinal direction of the explosion-proof valve is equal to the longitudinal direction of the first wall; in the longitudinal direction of the first wall, a distance s1 between an edge of the explosion-proof valve and an edge of the first wall is and s1 ≥ 3.5 mm; and / or in a width direction of the first wall, a distance s2 between an edge of the explosion-proof valve and an edge of the first wall is and s2 ≥ 10 mm. [6] Battery cell according to claim 4, characterized by , that the length of the explosion-proof valve is L, the width of the explosion-proof valve is B, and 1 ≤ L / B ≤ 5. [7] Battery cell according to claim 1, characterized by , that the housing further comprises a positive cover plate and a negative cover plate, and that the positive cover plate and the negative cover plate are each mounted on openings at two ends of the cylindrical structure to enclose and form a receiving chamber for receiving a raw cell. [8] Battery cell according to claim 7, characterized bythat it also includes a support plate; the support plate is provided between the side wall on which the explosion-proof valve is mounted and the raw cell, and the support plate is formed with a channel. [9] Battery cell according to claim 8, characterized by , that it also includes an insulating protective film; the insulating protective film encloses side sections of the raw cell and the support plate is enclosed within the insulating protective film. [10] Power device, characterized by that it comprises the battery cell according to any one of claims 1 to 9.

Images