Cylindrical battery

Abstract

The utility model relates to the technical field of batteries, and provides a cylindrical battery which comprises a battery cell and a battery shell, the battery cell is located in the battery shell, the battery shell comprises a main shell body and a cover plate, an opening is formed in the main shell body, the cover plate is buckled on the opening, the main shell body comprises a steel shell, a first protective layer and a second protective layer, and the first protective layer and the second protective layer are arranged in the steel shell. The steel shell comprises an inner surface facing the battery cell and an outer surface deviating from the battery cell; the first protective layer covers at least part of the inner surface of the steel shell; the second protective layer covers at least part of the outer surface of the steel shell; the ratio of the sum of the average thickness of the first protection layer and the average thickness of the second protection layer to the average thickness of the main shell is 0.005-0.3. The battery shell of the cylindrical battery is not easy to corrode.

Description

Technical Field

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

[0002] In the related art, the battery shell of the cylindrical battery generally adopts an aluminum shell structure. However, the strength of the aluminum shell is relatively low and it is easy to deform, and the cost of the aluminum shell is relatively high.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0004] The utility model provides a cylindrical battery, which can solve the problem that the battery shell is easily deformed.

[0005] Cylindrical batteries include:

[0006] Battery cells;

[0007] The battery housing, the battery cell is located inside the battery housing, the battery housing includes a main housing and a cover plate, the main housing is formed with an opening, the cover plate is buckled on the opening, and the main housing includes:

[0008] A steel shell, the steel shell comprising an inner surface facing the battery cell and an outer surface facing away from the battery cell;

[0009] A first protective layer covering at least a portion of the inner surface of the steel shell;

[0010] a second protective layer covering at least a portion of the outer surface of the steel shell;

[0011] The ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell is 0.005-0.3.

[0012] The utility model replaces the aluminum shell in the related art with a steel shell with greater strength to reduce the risk of deformation of the battery shell. In addition, since the steel shell is prone to corrosion, the utility model sets a first protective layer and a second protective layer on the inner and outer surfaces of the steel shell respectively to reduce the risk of corrosion of the steel shell, and also can physically protect the steel shell. Among them, if the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell is too large, the thickness of the steel shell is too small, and the strength of the main shell is insufficient; if the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell is too small, the steel shell is easily corroded. The utility model sets the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell to an appropriate size, which can not only ensure the strength of the main shell, but also reduce the risk of corrosion of the steel shell.

[0013] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to better understand the present disclosure, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. In addition, in the drawings, the same reference numerals represent the same or similar components in each drawing.

[0015] in:

[0016] Figure 1 It is a schematic structural diagram of an exemplary embodiment of a cylindrical battery disclosed in the present invention.

[0017] Description of reference numerals:

[0018] 1. Battery cell; 2. Battery shell; 21. Main shell; 211. Steel shell; 212. First protective layer; 213. Second protective layer; 22. Cover plate; 221. Cover plate body; 222. Third protective layer. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0020] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0021] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0022] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to one or more "upper", "lower", or "inner", "outer" of another element, it can not only be directly connected to the "upper", "lower", "inner", "outer" of another element or elements, but can also be indirectly connected to the "upper", "lower", "inner", "outer" of another element or elements through an intermediate element.

[0023] like Figure 1 The figure is a schematic diagram of the structure of an exemplary embodiment of the cylindrical battery disclosed in the present invention. The cylindrical battery comprises: a battery cell 1 and a battery shell 2, wherein the battery cell 1 is located inside the battery shell 2, and the battery shell 2 comprises a main shell 21 and a cover plate 22, wherein the main shell 21 is formed with an opening, and the cover plate 22 is buckled on the opening, and the main shell 21 comprises: a steel shell 211, a first protective layer 212, and a second protective layer 213, wherein the steel shell 211 comprises an inner surface facing the battery cell 1 and an outer surface facing away from the battery cell 1; the first protective layer 212 covers at least part of the inner surface of the steel shell 211; the second protective layer 213 covers at least part of the outer surface of the steel shell 211; wherein the ratio of the sum of the average thickness of the first protective layer 212 and the second protective layer 213 to the average thickness of the main shell 21 is 0.005-0.3.

[0024] This exemplary embodiment replaces the aluminum shell in the related art with a stronger steel shell to reduce the risk of deformation of the battery shell. In addition, since the steel shell is prone to corrosion, this exemplary embodiment sets a first protective layer and a second protective layer on the inner and outer surfaces of the steel shell, respectively, to reduce the risk of corrosion of the steel shell, and also to physically protect the steel shell. Among them, if the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell is too large, the thickness of the steel shell is too small, and the strength of the main shell is insufficient; if the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell is too small, the steel shell is easily corroded. This exemplary embodiment sets the ratio of the sum of the average thickness of the first protective layer and the second protective layer to the average thickness of the main shell to an appropriate size, which can not only ensure the strength of the main shell, but also reduce the risk of corrosion of the steel shell.

[0025] In this exemplary embodiment, the ratio of the sum of the average thickness of the first protective layer 212 and the second protective layer 213 to the average thickness of the main shell 21 can be equal to 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, etc. In addition, it should be noted that the thickness of the main shell 21 is the total thickness of the steel shell 211, the first protective layer 212 and the second protective layer 213.

[0026] In this exemplary embodiment, the thickness of the first protective layer 212 may be less than the thickness of the second protective layer 213. The outer surface of the steel shell 211 is more susceptible to corrosion due to exposure to air, and in this exemplary embodiment, the second protective layer 213 located on the outer surface of the steel shell 211 is set to a greater thickness, thereby reducing the risk of corrosion of the outer surface of the steel shell 211.

[0027] In the present exemplary embodiment, the ratio of the thickness of the first protective layer 212 to the thickness of the second protective layer 213 is 0.1-0.95. For example, the ratio of the thickness of the first protective layer 212 to the thickness of the second protective layer 213 may be equal to 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc. If the ratio of the thickness of the first protective layer 212 to the thickness of the second protective layer 213 is too small, the thickness of the first protective layer 212 is too small, and the inner surface of the steel shell is easily corroded. If the ratio of the thickness of the first protective layer 212 to the thickness of the second protective layer 213 is too large, the thickness of the second protective layer 213 is too small, and the outer surface of the steel shell is easily corroded. In this exemplary embodiment, the ratio of the thickness of the first protective layer 212 to the thickness of the second protective layer 213 is set to a suitable value, which can reduce the risk of corrosion of the inner and outer surfaces of the steel shell 211.

[0028] In this exemplary embodiment, Figure 1As shown, the first protective layer 212 partially extends to at least part of the side of the steel shell 211 facing the cover plate 22, and the cover plate 22 includes: a cover plate body 221, a third protective layer 222, and the third protective layer 222 covers at least part of the surface of the cover plate body 221 facing the battery cell 1. The cover plate 22 is welded by the third protective layer 222 and the first protective layer 212 extending to the side of the steel shell 211 facing the cover plate 22; the ratio of the thickness of the third protective layer 222 to the thickness of the first protective layer 212 is 0.4-1.5. For example, the ratio of the thickness of the third protective layer 222 to the thickness of the first protective layer 212 can be equal to 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc. The ratio of the thickness of the third protective layer 222 to the thickness of the first protective layer 212 is too small. When the third protective layer 222 and the first protective layer 212 are welded, the third protective layer 222 is easily welded through; the ratio of the thickness of the third protective layer 222 to the thickness of the first protective layer 212 is too large. The thickness of the third protective layer 222 is too large, the thickness of the cover plate body 221 is too small, the strength of the cover plate 22 is weak, and there is a risk of deformation of the cover plate.

[0029] In this exemplary embodiment, the cover plate body 221 may also be a steel structure. The steel shell 211 and the cover plate body 221 may be made of stainless steel, carbon steel, or the like.

[0030] In this exemplary embodiment, the thickness of the main shell 21 is 0.2mm-0.7mm. For example, the thickness of the main shell 21 can be equal to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, etc. If the thickness of the main shell 21 is too large, the main shell 21 occupies a large space inside the battery shell, which will result in a lower energy density of the cylindrical battery; if the thickness of the main shell 21 is too small, the main shell 21 will be easily deformed. In this exemplary embodiment, the thickness of the main shell 21 is set to a suitable size, which can not only ensure the energy density of the cylindrical battery, but also reduce the risk of deformation of the main shell 21.

[0031] In this exemplary embodiment, the main housing 21 and / or the cover plate 22 are electrically connected to the battery cell 1. The first protective layer 212 and the second protective layer 213 are insulating structures. The ratio of the sum of the average thickness of the first protective layer 212 and the second protective layer 213 to the average thickness of the main housing 21 is too large, the thickness of the steel shell 211 is too small, and the flow area of ​​the main housing 21 is small, which will cause the battery housing to generate heat seriously and the battery is prone to thermal runaway. In this exemplary embodiment, the ratio of the sum of the average thickness of the first protective layer 212 and the second protective layer 213 to the average thickness of the main housing 21 is set to a suitable size, which can reduce the risk of thermal runaway of cylindrical batteries.

[0032] In the present exemplary embodiment, the sum of the average thickness of the first protective layer 212 and the second protective layer 213 is 3 μm-20 μm. For example, the sum of the average thickness of the first protective layer 212 and the second protective layer 213 may be equal to 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc.

[0033] In this exemplary embodiment, the battery cell 1 may be a wound battery cell, and the geometric diameter of the battery cell 1 may be greater than or equal to 36 mm. For example, the geometric diameter of the battery cell 1 may be equal to 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, etc. In this exemplary embodiment, the geometric diameter of the battery cell 1 is set to a larger value, which can improve the energy density of the cylindrical battery.

[0034] It should be noted that when the battery cell 1 is a cylinder, the geometric diameter of the battery cell 1 is the diameter of the cylinder. It should be understood that in other exemplary embodiments, the battery cell 1 can also be other cylindrical structures, and the geometric diameter of the battery cell 1 is the diameter of the largest circle located within the edge of the cross section of the winding core body, and the cross section of the battery cell 1 is perpendicular to its winding axis.

[0035] In this exemplary embodiment, the thermal conductivity of the main housing 21 is greater than or equal to 30w / m·k. For example, the thermal conductivity of the main housing 21 may be equal to 30w / m·k, 32w / m·k, 34w / m·k, 36w / m·k, 38w / m·k, 40w / m·k, 42w / m·k, 44w / m·k, 46w / m·k, 48w / m·k, 50w / m·k, 52w / m·k, 54w / m·k, 56w / m·k, 58w / m·k, 60w / m·k, etc. In this exemplary embodiment, the thermal conductivity of the main housing 21 can be adjusted by adjusting the thickness of the steel shell 211, the first protective layer 212, and the second protective layer 213. In this exemplary embodiment, the thermal conductivity of the main housing 21 is set to a larger value, so that the battery cell 1 can quickly dissipate heat outward through the main housing 21.

[0036] In this exemplary embodiment, the battery cell 1 may include a first pole tab and a second pole tab with opposite polarities, and the first pole tab is electrically connected to the main housing 21. Since the main housing 21 is connected to the first pole tab, the main housing 21 has a certain potential, so that the main housing 21 is more easily corroded. This exemplary embodiment can reduce the risk of corrosion of the main housing 21 through the above structure. The first pole tab may be a positive pole tab, and the second pole tab may be a negative pole tab, or the first pole tab may be a negative pole tab, and the second pole tab may be a positive pole tab.

[0037] In this exemplary embodiment, the first protective layer 212, the second protective layer 213, and the third protective layer 222 may include one or more layers of a nickel layer, a chromium layer, a zinc layer, a tin layer, an aluminum layer, and a copper layer. The first protective layer 212 and the second protective layer 213 may be formed on the steel shell 211 by electroplating, and the third protective layer 222 may also be formed on the cover plate body 221 by electroplating. It should be understood that in other exemplary embodiments, the first protective layer 212, the second protective layer 213, and the third protective layer 222 may also be other metal material layers, as long as the activity of the metal material layer is lower than that of the steel material, the metal material layer may play a certain anti-corrosion role on the steel shell.

[0038] In this exemplary embodiment, the battery may be a lithium-ion battery. It should be understood that in other exemplary embodiments, the battery may also be a nickel-cadmium battery, a nickel-metal hydride battery, a lithium polymer battery, or the like.

[0039] The battery may be a wound battery, that is, a first pole sheet, a second pole sheet with electrical properties opposite to the first pole sheet, and a diaphragm sheet arranged between the first pole sheet and the second pole sheet are wound to obtain a wound battery cell.

[0040] The present exemplary embodiment also provides a battery device, which includes the cylindrical battery described above.

[0041] In this exemplary embodiment, the battery device is a battery module or a battery pack.

[0042] The battery module includes a plurality of batteries, and the battery module may further include an end plate and a side plate, and the end plate and the side plate are used to fix the plurality of batteries. The battery may be a cylindrical battery, and the cylindrical battery may be arranged on a support plate to form a battery module.

[0043] The battery pack includes a plurality of batteries and a box body, and the box body is used to fix the plurality of batteries.

[0044] It should be noted that the battery pack includes a battery, and the battery may be multiple, and the multiple batteries are arranged in the box. Among them, the multiple batteries can be installed in the box after forming a battery module. Alternatively, the multiple batteries can be directly arranged in the box, that is, there is no need to group the multiple batteries, and the box is used to fix the multiple batteries.

[0045] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing what is disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered merely as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0046] The drawings in the present disclosure only relate to the structures involved in the present disclosure, and other structures may refer to the usual design. In the absence of conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other to obtain new embodiments. It should be understood by those of ordinary skill in the art that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and should be included in the scope of the claims of the present disclosure.

[0047] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A cylindrical battery, characterized in that: The cylindrical battery comprises: Battery cell (1); A battery housing (2), wherein the battery cell (1) is located inside the battery housing (2), the battery housing (2) comprises a main housing (21) and a cover plate (22), the main housing (21) is formed with an opening, the cover plate (22) is buckled on the opening, and the main housing (21) comprises: A steel shell (211), the steel shell (211) comprising an inner surface facing the battery core (1) and an outer surface facing away from the battery core (1); A first protective layer (212) covers at least a portion of the inner surface of the steel shell (211); A second protective layer (213) covering at least a portion of the outer surface of the steel shell (211); The ratio of the sum of the average thickness of the first protective layer (212) and the second protective layer (213) to the average thickness of the main shell (21) is 0.005-0.

3.

2. The cylindrical battery according to claim 1, characterized in that: The thickness of the first protective layer (212) is smaller than the thickness of the second protective layer (213).

3. The cylindrical battery according to claim 2, characterized in that: The ratio of the thickness of the first protective layer (212) to the thickness of the second protective layer (213) is 0.1-0.

95.

4. The cylindrical battery according to claim 1, characterized in that: The first protective layer (212) partially extends to at least a portion of the side surface of the steel shell (211) facing the cover plate (22), and the cover plate (22) comprises: Cover plate body (221); a third protective layer (222) covering at least a portion of the surface of the cover plate body (221) facing the battery core (1), the cover plate (22) being welded through the third protective layer (222) and the first protective layer (212) extending to the side of the steel shell (211) facing the cover plate (22); The ratio of the thickness of the third protective layer (222) to the thickness of the first protective layer (212) is 0.4-1.

5.

5. The cylindrical battery according to claim 1, characterized in that: The main housing (21) and / or the cover plate (22) are electrically connected to the battery core (1).

6. The cylindrical battery according to claim 1, characterized in that: The sum of the average thicknesses of the first protective layer (212) and the second protective layer (213) is 3 μm-20 μm.

7. The cylindrical battery according to any one of claims 1 to 6, characterized in that: The battery core (1) is a wound battery core, and the geometric diameter of the battery core (1) is greater than or equal to 36 mm.

8. The cylindrical battery according to any one of claims 1 to 6, characterized in that: The thermal conductivity of the main shell (21) is greater than or equal to 30w / m·k.

9. The cylindrical battery according to any one of claims 1 to 6, characterized in that: The battery cell (1) comprises a first pole lug and a second pole lug with opposite polarities, and the first pole lug is electrically connected to the main housing (21).

10. The cylindrical battery according to any one of claims 1 to 6, characterized in that: The first protective layer (212) and the second protective layer (213) include one or more layers of a nickel layer, a chromium layer, a zinc layer, a tin layer, an aluminum layer, and a copper layer.

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