Battery assembly and single battery

Abstract

The invention relates to the technical field of lithium batteries, in particular to a battery assembly and a single battery. The battery assembly comprises a pole group, a pole lug and a cover plate; the cover plate comprises a cover plate pole, and the cover plate pole comprises a pole part and a pole base arranged towards the pole group; the pole group has a width direction and a length direction, the pole base extends along the width direction, and the pole base is attached to the pole group; the pole lugs are led out from the pole group and are welded with the surface, far away from the pole group, of the pole column base, the column parts are connected with the pole column base, and the column parts and the pole lugs are arranged at intervals in the width direction; the battery assembly satisfies the following conditions: 1.5 mm < = t < = 2.5 mm, and C < = 40 mm; wherein t is the thickness of the pole base, and C is the minimum distance from the first side of the pole base to the pole part. According to the battery assembly and the single battery provided by the invention, the problem that when thermal runaway occurs in an existing battery cell structure, the pole group randomly moves along with high-temperature and high-pressure airflow to shield the anti-explosion valve and further shield the exhaust channel is solved.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a battery assembly and a single battery. Background Art

[0002] Lithium-ion batteries have become the representative of modern high-performance batteries due to their advantages such as high operating voltage, large capacity, low self-discharge, good cycle performance, long service life, light weight and small size.

[0003] Long cell lithium ion battery Fig.10 and Fig.11 As shown, it is usually designed to have pole ears on both sides, and its structure includes: cover plate (with integrated pole column, explosion-proof valve, injection hole, etc.), shell, pole group, electrolyte, etc. After the cover plate and shell are welded, a closed space with certain mechanical strength is formed to protect the pole group; the pole group is fixed to the pole column base of the cover plate on both sides through laser welding through the pole ears on both sides to achieve electrical connection. In addition, the second plastic parts of the cover plate are designed at the pole ears on both sides to protect the pole ears and provide bending space for the pole ears; the cover plate is integrated with an explosion-proof valve structure, which is mainly used for the directional discharge of internal high-temperature and high-pressure gas when the battery has thermal runaway due to internal short circuit, so as to improve the safety performance of the battery.

[0004] The pole ear of the above structure is welded to the bottom of the base of the pole column of the cover plate. There is a bending height space for the pole ear between the pole ear and the pole group. The pole ear is mainly insulated and fixed by the second plastic part of the cover plate. However, the insulating material of the second plastic part is generally made of PP material, and its strength and high temperature resistance are very limited, generally around 150 degrees. The temperature at which thermal runaway occurs in the battery cell is usually much higher than the melting point of these insulating materials. Once the insulating material of the second plastic part melts and fails, only the pole group is left inside the battery cell. This will cause the pole ear to lose its fixed support and increase in length along the length direction of the battery cell, resulting in an increase in the gap between the pole group and the cover plate and the shell. At this time, the pole group has a high degree of freedom inside the battery cell. When the high-temperature and high-pressure gas is exhausting in the direction of the explosion-proof valve, the pole group will move randomly with the high-temperature and high-pressure airflow to block the explosion-proof valve and the exhaust channel, greatly reducing the exhaust effect of the explosion-proof valve and reducing the safety performance of the battery cell.

[0005] In addition, during the welding process of the pole ear and the cover plate pole base of the above structure, the pole base is not strong enough, and the pole base is easily deformed during welding, resulting in poor welding effect, and the welding point is prone to tearing. The pole group will also move randomly with the high-temperature and high-pressure airflow to block the explosion-proof valve and the exhaust channel, which greatly reduces the exhaust effect of the explosion-proof valve and reduces the safety performance of the battery cell. Summary of the invention

[0006] The purpose of the present application is to provide a battery assembly and a single cell, thereby solving the problem that when thermal runaway occurs in the existing battery cell structure, the pole group will randomly move with the high-temperature and high-pressure airflow to block the explosion-proof valve and then block the exhaust channel.

[0007] According to a first aspect of the present application, a battery assembly is provided, the battery assembly comprising a pole group, a pole ear and a cover plate; the cover plate comprises a cover plate pole, the cover plate pole comprises a column portion and a pole base arranged toward the pole group; the pole group has a width direction and a length direction perpendicular to each other, the pole base extends along the width direction, and the pole base is in contact with the pole group; the pole ear is led out from the pole group and welded to the surface of the pole base away from the pole group, the column portion is connected to the pole base, and the column portion and the pole ear are spaced apart in the width direction; the pole base comprises a first side and a second side opposite to each other in the width direction, the pole ear is closer to the first side than the column portion; the column portion is closer to the second side than the pole ear; the battery assembly satisfies: 1.5mm≤t≤2.5mm, C≤40mm; wherein t is the thickness of the pole base in the length direction, and C is the minimum distance from the first side of the pole base to the side of the column portion close to the pole ear.

[0008] In any of the above technical solutions, further, the pole group also has a thickness direction which is respectively perpendicular to the width direction and the length direction; the pole base includes a third side and a fourth side which are opposite to each other in the thickness direction, and the third side of the pole base is provided with a notch, and the notch divides the pole base into a first section and a second section which are connected to each other; the size of the second section in the thickness direction is larger than the size of the first section in the thickness direction, and the size of the second section in the width direction is smaller than the size of the first section in the width direction, the column portion is welded to the second section, and the pole ear is welded to the first section after being bent through the notch.

[0009] In any of the above technical solutions, further, the battery assembly satisfies: 3mm≤AB≤5mm; wherein A is the dimension of the second segment in the thickness direction, and B is the dimension of the first segment in the thickness direction.

[0010] In any of the above technical solutions, further, the pole base includes a through hole for welding the column portion; the column portion is welded to the inner wall of the through hole of the pole base; the battery assembly satisfies: 25mm≤S≤45mm; wherein S is the circumference of the weld formed by welding the column portion to the inner wall of the through hole of the pole base.

[0011] In any of the above technical solutions, further, the cover plate also includes a cover plate body, a connecting block and a first plastic part; the column portion passes through the pole base, the cover plate body, the first plastic part and the connecting block in sequence; the size of the connecting block in the width direction is smaller than the size of the pole base in the width direction.

[0012] In any of the above technical solutions, further, the battery assembly also includes an insulating member; the insulating member includes a side portion and a bottom portion connected to each other, the side portion is arranged between the cover plate body and the pole group, and the side portion is arranged around the pole ear and the cover plate pole; the bottom portion is fitted between the pole base and the pole group.

[0013] In any of the above technical solutions, further, the insulating member also includes a top connected to the side; a portion of the top is arranged between the cover body and the pole ear, and a portion of the top is arranged between the cover body and the cover pole; a gap is provided between the pole ear and the second side of the pole base for the installation of the top.

[0014] In any of the above technical solutions, further, the battery assembly also includes a sealing plate; the cover plate body and the insulating member are both provided with through holes penetrating through themselves; the through holes of the cover plate body and the through holes of the insulating member both cover the pole ears, and the sealing plate is welded to the inner wall of the through holes of the cover plate body.

[0015] According to a second aspect of the present application, a single cell is provided, comprising the battery assembly as described above.

[0016] In any of the above technical solutions, further, the single cell includes a first cover plate and a second cover plate, the first cover plate and the second cover plate are respectively arranged at the two ends of the electrode group; the first cover plate includes a first polarity pole, the second cover plate includes a second polarity pole; the first polarity pole is the cover plate pole.

[0017] In any of the above technical solutions, further, the single battery also includes an explosion-proof valve; the explosion-proof valve is arranged on the second cover plate.

[0018] The battery assembly of the present application includes a pole group, a pole ear and a cover plate. Among them, the cover plate includes a cover plate pole, and the cover plate pole includes a pole portion and a pole base arranged toward the pole group; the pole group has a width direction and a length direction perpendicular to each other, the pole base extends along the width direction, and the pole base is in contact with the pole group; the pole ear is led out from the pole group and welded to the surface of the pole base away from the pole group, the pole portion is connected to the pole base, and the pole portion and the pole ear are arranged at intervals in the width direction; the pole base includes a first side and a second side opposite to each other in the width direction, and the pole ear is closer to the first side than the pole portion; the pole portion is closer to the second side than the pole ear; the battery assembly satisfies: 1.5mm≤t≤2.5mm, C≤40mm; wherein t is the thickness of the pole base in the length direction, and C is the minimum distance from the first side of the pole base to the side of the pole portion close to the pole ear.

[0019] According to the above technical features, the beneficial effects of this application are:

[0020] The present application adjusts the welding position of the pole ear to be welded above the pole base. The welded pole ear is firmly fixed on the pole base, and the bottom surface of the pole base is close to the pole group, with no gap between the pole group and the pole group. When a single cell has thermal runaway and the second plastic part of the cover fails due to melting, the pole group can still rely on the firm welding of the pole ear and the pole base without displacement along the length direction of the pole group, thereby preventing the pole group from blocking the exhaust channel of the explosion-proof valve on the cover.

[0021] On this basis, the battery assembly of the present application satisfies: 1.5mm≤t≤2.5mm, C≤40mm; wherein t is the thickness of the pole base, and C is the minimum distance from the first side of the pole base to the column. In other words, in order to ensure the structural strength of the pole base, the extended portion of the pole base will not bend and deform due to the pressure of the welding head during the welding of the pole lugs, and t is required to be between 1.5mm and 2.5mm, and the length of the portion of the pole base that exceeds the column is ≤40mm. In this way, all thermal runaway safety tests of the battery assembly are passed, and after the test, the pole lugs and pole bases are still firmly connected and will not fall off, and there is no obvious movement of the pole group.

[0022] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A partial structural schematic diagram of a battery assembly according to an embodiment of the present application is shown;

[0025] Figure 2 Show Figure 1 Schematic diagram of the structure after the connection block and the first plastic part are installed;

[0026] Figure 3 A schematic diagram showing the structure of a cover plate pole according to an embodiment of the present application is shown;

[0027] Figure 4 Show Figure 2 Schematic diagram of the structure after installing the top cover sheet and insulation parts;

[0028] Figure 5 A front view showing one end of a single cell according to an embodiment of the present application;

[0029] Figure 6 Show Figure 5 AA cross-sectional structural diagram;

[0030] Figure 7 Show Figure 5 BB cross-sectional structure diagram;

[0031] Figure 8 A schematic diagram showing an exploded structure of one end of a single cell according to an embodiment of the present application;

[0032] Fig. 9 A schematic diagram showing an exploded structure of the other end of a single cell according to an embodiment of the present application;

[0033] Fig.10 A schematic diagram showing a cross-sectional structure of one end of a single cell in the prior art is shown;

[0034] Fig.11 A schematic cross-sectional structure diagram of the other end of a single cell in the prior art is shown.

[0035] Icons: 100-ear; 200-cover; 201-window; 211-pole base; 2111-first section; 2112-second section; 212-column; 220-first plastic part; 230-second plastic part; 240-connecting block; 250-top cover; 300-pole group; 400-insulating part; 410-top; 420-side; 430-bottom; 500-sealing plate; 600-explosion-proof valve; E-ear bending space; X-length direction; Y-width direction; Z-thickness direction. DETAILED DESCRIPTION

[0036] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0037] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0038] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0039] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0040] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0041] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0042] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0043] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0044] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0045] Prior to the present application, existing long-cell lithium-ion batteries such as Fig.10 and Fig.11 As shown, the pole group 300 is fixed to the bottom of the cover plate pole base 211 on both sides by laser welding through the pole ears 100 on both sides to achieve electrical connection. In addition, a second cover plate plastic part 230 is designed at the pole ears on both sides to protect the pole ears 100 and provide a bending space E for the pole ears.

[0046] However, in the above structure, when thermal runaway occurs in the battery cell, once the insulating material such as the second plastic part 230 melts and fails, only the electrode group 300 will be left inside the battery cell. This will cause the pole ear 100 to lose its fixed support and increase in length along the length direction of the battery cell, resulting in an increase in the gap between the electrode group 300 and the cover plate and the shell. At this time, the electrode group 300 has a high degree of freedom inside the battery cell. When the high-temperature and high-pressure gas is exhausting in the direction of the explosion-proof valve, the electrode group 300 will move randomly with the high-temperature and high-pressure airflow to block the explosion-proof valve and the exhaust channel, thereby greatly reducing the exhaust effect of the explosion-proof valve and reducing the safety performance of the battery cell.

[0047] In addition, during the welding process of the pole ear 100 and the cover plate pole base 211 of the above structure, the pole base is not strong enough, and the pole base is easily deformed during welding, resulting in poor welding effect, and the welding point is prone to tearing. The pole group will also move randomly with the high-temperature and high-pressure airflow to block the explosion-proof valve and the exhaust channel, which greatly reduces the exhaust effect of the explosion-proof valve and reduces the safety performance of the battery cell.

[0048] In view of this, the first aspect of the present application provides a battery assembly, thereby solving the problem that when thermal runaway occurs in the existing battery cell, the electrode group will randomly move with the high-temperature and high-pressure airflow to block the explosion-proof valve and then block the exhaust channel. Figures 1 to 9 The battery assembly according to some embodiments of the present application is described. For ease of description, the following description will be based on an example in which the length direction X, thickness direction Z and width direction Y of the cover plate pole are perpendicular to each other.

[0049] In addition, for the convenience of description, the pole tab 100 , pole base 211 and pole group 300 of the present application and the pole tab 100 , pole base 211 and pole group 300 of the prior art use the same reference numerals.

[0050] like Figure 1 and Figure 2 As shown, the battery assembly of the present application includes a pole group 300 , a pole ear 100 and a cover plate 200 . Among them, the cover plate 200 includes a cover plate pole, and the cover plate pole includes a column portion 212 and a pole base 211 arranged toward the pole group; the pole group 300 has a width direction Y, the pole base 211 extends along the width direction Y, and the pole base 211 is in contact with the pole group 300; the pole ear 100 is led out from the pole group 300 and welded to the surface of the pole base 211 away from the pole group, the column portion 212 is connected to the pole base 211, and the column portion 212 and the pole ear 100 are spaced apart in the width direction Y; the pole base 211 includes a first side and a second side opposite to each other in the width direction Y, and the pole ear 100 is closer to the first side than the column portion 212; the column portion is closer to the second side than the pole ear; the battery assembly satisfies: 1.5mm≤t≤2.5mm, C≤40mm; wherein t is the thickness of the pole base 211, and C is the minimum distance from the first side of the pole base 211 to the column portion 212.

[0051] That is, the present application adjusts the welding position of the pole tab 100 to be welded above the pole base 211, and the welded pole tab 100 is firmly fixed on the pole base 211, and the bottom surface of the pole base 211 is in close contact with the pole group 300, with no gap between the pole group 300. When thermal runaway occurs in the single cell and the second plastic part of the cover fails due to melting, the pole group can still rely on the firm welding of the pole tab and the pole base without displacement along the length direction of the pole group, thereby preventing the pole group from blocking the exhaust channel of the explosion-proof valve on the cover.

[0052] On this basis, the battery assembly of the present application satisfies: 1.5mm≤t≤2.5mm, C≤40mm; wherein t is the thickness of the pole base 211, and C is the minimum distance from the first side of the pole base 211 to the side of the column 212 close to the pole ear (the minimum distance from the edge of the column to one side of the pole base). In other words, in order to ensure the structural strength of the pole base 211, the extended portion of the pole base will not bend and deform due to the pressure of the welding head during the welding of the pole ear, and t is required to be between 1.5mm and 2.5mm, and the length of the portion of the pole base that exceeds the column is ≤40mm. In this way, all thermal runaway safety tests of the battery assembly are passed, and the pole ear and the pole base are still firmly connected after the test without falling off, and there is no obvious movement of the pole group.

[0053] In addition, the bending and welding of the tab 100 and the welding of the column 212 are further facilitated. Figure 2 As shown, the pole base 211 of the present application includes a third side and a fourth side opposite to each other in the thickness direction Z, and a notch is provided on the third side of the pole base 211. The notch divides the pole base 211 into a first section 2111 and a second section 2112 connected to each other, wherein the size of the second section 2112 in the thickness direction Z is greater than the size of the first section 2111 in the thickness direction Z. In this way, the space left by the notch can be bent by the tab 100, that is, the tab 100 can be welded to the first section 2111 after being bent through the notch. The second section 2112 has a large size in the thickness direction Z, and can be welded to the bottom end of the column 212.

[0054] In addition, in this embodiment, if Figure 2 As shown, the size of the second section 2112 in the width direction Y is smaller than the size of the first section 2111 in the width direction Y. In this way, the size of the first section 2111 in the width direction Y is large, and sufficient space can be reserved for welding the tab 100, which can not only improve the welding strength of the tab 100, but also ensure the flow area.

[0055] On this basis, if Figure 3As shown, the battery assembly of the present application satisfies: 25mm≤S≤45mm. The pole base includes a through hole for welding the pole part, and the pole part is welded to the inner wall of the through hole of the pole base; S is the circumference of the weld formed by welding the pole part to the inner wall of the through hole of the pole base. That is, ensure that S has sufficient length to ensure the firmness of the pole welding, which is sufficient to support the pressure on the pole base during the welding of the pole lug.

[0056] In addition, the battery assembly of the present application satisfies: 3mm≤AB≤5mm. A is the dimension of the second section in the thickness direction, and B is the dimension of the first section in the thickness direction. In this way, it is ensured that the pole ear penetrates the gap between the pole base and the edge of the cover plate, and the pole group can be normally assembled and welded with the cover plate. If the B value is too small, it will affect the structural strength of the pole base, and if the B value is too large, it will affect the normal assembly of the cover plate.

[0057] In order to verify the design effect, different single cells were arranged to verify the welding area, and the results are as follows.

[0058]

[0059]

[0060] It can be seen that when the thickness of the pole base t is less than 1.5mm, the strength of the pole base is insufficient, and bending and deformation occur during welding; when AB is less than 3mm, the width of the space for piercing the pole ear is insufficient, and the piercing process of the pole ear is prone to interfere with the cover plate or the pole group base, affecting production efficiency; when the C value is too large, the force on the pole group base during welding is too large, and the strength is insufficient and it is easy to deform; the S value must be between 25mm-45mm to ensure that the strength of the pole after welding meets the design requirements.

[0061] In the embodiments of the present application, Figure 4 and Figure 7 As shown, the cover plate 200 further includes a cover plate body (for example, a top cover sheet 250), a connection block 240 and a first plastic part 220. The column portion 212 sequentially passes through the pole base 211, the cover plate body, the first plastic part 220 and the connection block 240, and the size of the connection block 240 in the width direction Y is smaller than the size of the pole base 211 in the width direction Y.

[0062] In summary, compared with the prior art, the present application lengthens the pole base 211 of the pole of the cover plate, and adjusts the welding position of the pole ear 100 to be welded above the pole base 211. The pole ear 100 after welding is firmly fixed on the pole base 211, and the bottom surface of the pole base 211 is close to the pole group, and there is no gap between the pole group 300. When thermal runaway occurs in the single cell and the second plastic part of the cover plate fails due to melting, the pole group 300 can still rely on the firm welding of the pole ear 100 and the pole base 211 without displacement along the length direction X of the pole group 300, thereby preventing the pole group 300 from blocking the exhaust channel of the explosion-proof valve on the cover plate.

[0063] On this basis, 1.5mm≤t≤2.5mm and C≤40mm are reasonably limited to ensure the structural strength of the pole base, where t is the thickness of the pole base and C is the minimum distance from the first side of the pole base to the column.

[0064] Furthermore, in an embodiment of the present application, the battery assembly further includes an insulating member 400. Figure 4 , Figure 6 and Figure 7 As shown, the insulator includes a top portion 410 , side portions 420 , and a bottom portion 430 .

[0065] The top 410 is connected to the side 420, part of the top 410 is arranged between the cover body and the pole ear 100, part of the top 410 is arranged between the cover body and the cover pole, and the pole ear 100 is provided with a gap for the installation of the top 410 from the second side of the pole base 211. In this way, the top 410 is arranged between the pole ear 100 / cover pole and the cover body (for example, including the top cover sheet 250), which plays an insulating role.

[0066] The side portion 420 is connected to the top portion 410, and the side portion 420 is disposed between the cover plate body and the pole group 300, and the side portion 420 is disposed around the pole lug 100 and the cover plate pole column. In this way, the side portion 420 is disposed with the pole group 300, and around the pole lug 100 and the cover plate pole column, which can protect the cover plate pole column and the pole lug 100 while providing installation space.

[0067] The bottom 430 is connected to the side 420 , and is attached between the pole base 211 and the pole group 300 . The bottom 430 can provide insulation and support for the pole base 211 , thereby facilitating welding of the pole tab 100 .

[0068] It is also worth mentioning that Figure 4 and Figure 8As shown, the battery assembly of the present application also includes a sealing plate 500. The cover plate body (for example, including the top cover sheet 250) and the insulating member 400 are both provided with through holes (opening windows 201) penetrating through them, and the through holes of the cover plate body and the through holes of the insulating member 400 both cover the tabs 100, and the sealing plate 500 is welded to the inner wall of the through holes of the cover plate body. In this way, when the single battery is specifically assembled, the tabs 100 can be bent and welded through the through holes of the cover plate body (for example, including the top cover sheet 250) and the insulating member 400, and then sealed with the sealing plate 500 after welding.

[0069] The specific process is as follows:

[0070] The assembly process of the single cell is as follows: lamination - pre-welding and cutting of the pole lugs - assembly of the pole group and the cover plate - bending and welding of the pole lugs to the pole column base of the cover plate - welding of the cover plate sealing plate - pole group into the shell - welding and sealing of the opposite side cover plate.

[0071] According to a second aspect of the present application, a single cell is provided, comprising the battery assembly as described above.

[0072] Furthermore, if Figure 8 and Fig. 9 As shown, the single cell includes a first cover plate and a second cover plate, which are respectively arranged at two ends of the electrode group. The first cover plate includes a first polarity pole, the second cover plate includes a second polarity pole, and the first polarity pole is a cover plate pole.

[0073] That is to say, among the cover plates at both ends of the single cell of the present application (the two cover plates at both ends in the length direction X), the pole column and the pole ear 100 of one of the cover plates can be designed as above, because the pole ear 100 and the pole column at one end are firmly fixed to limit the displacement of the pole group 300 along the length direction X, thereby preventing the pole group 300 from blocking the exhaust channel of the explosion-proof valve 600 on the cover plate.

[0074] Furthermore, considering the effective space of the cover plate, the explosion-proof valve 600 can be arranged on the second cover plate, that is, the explosion-proof valve 600 is arranged on the cover plate that does not adopt the above design.

[0075] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the aforementioned embodiments within the technical scope disclosed in the present application, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application.

Claims

1. A battery assembly, characterized in that: The battery assembly comprises a pole group (300), a pole ear (100) and a cover plate (200); the cover plate (200) comprises a cover plate pole, and the cover plate pole comprises a pole portion (212) and a pole base (211) arranged toward the pole group (300); The pole group (300) has a width direction (Y) and a length direction (X) that are perpendicular to each other, the pole base (211) extends along the width direction (Y), and the pole base (211) is in contact with the pole group (300); The pole lug (100) is led out from the pole group (300) and welded to a surface of the pole base (211) away from the pole group (300); the column portion (212) is connected to the pole base (211), and the column portion (212) and the pole lug (100) are spaced apart in the width direction (Y); The pole base (211) comprises a first side and a second side opposite to each other in the width direction (Y); compared with the pole portion (212), the pole lug (100) is closer to the first side; compared with the pole lug (100), the pole portion (212) is closer to the second side; The battery assembly meets the following requirements: 1.5 mm ≤ t ≤ 2.5 mm, C ≤ 40 mm; Wherein, t is the thickness of the pole base (211) in the length direction (X), and C is the minimum distance from the first side of the pole base (211) to the side of the column portion (212) close to the pole lug (100).

2. The battery assembly according to claim 1, characterized in that: The pole group also has a thickness direction (Z) which is perpendicular to the width direction (Y) and the length direction (X). The pole base (211) comprises a third side and a fourth side opposite to each other in the thickness direction (Z), the third side of the pole base (211) is provided with a notch, and the notch divides the pole base (211) into a first section (2111) and a second section (2112) connected to each other; The dimension of the second section (2112) in the thickness direction (Z) is greater than the dimension of the first section (2111) in the thickness direction (Z), and the dimension of the second section (2112) in the width direction (Y) is smaller than the dimension of the first section (2111) in the width direction (Y). The column portion (212) is welded to the second section (2112), and the pole tab (100) is welded to the first section (2111) after being bent through the notch portion.

3. The battery assembly according to claim 2, characterized in that: The battery assembly meets the following requirements: 3mm≤AB≤5mm; Wherein, A is the dimension of the second section (2112) in the thickness direction (Z), and B is the dimension of the first section (2111) in the thickness direction.

4. The battery assembly according to claim 1, characterized in that: The pole base (211) comprises a through hole for welding the pole portion (212); The column portion (212) is welded to the inner wall of the through hole of the pole base (211); The battery assembly meets the following requirements: 25mm≤S≤45mm; Wherein, S is the circumference of a weld formed by welding the column portion (212) and the inner wall of the through hole of the pole base (211).

5. The battery assembly according to claim 1, characterized in that: The cover plate (200) further comprises a cover plate body, a connecting block (240) and a first plastic part (220); The column portion (212) sequentially passes through the pole base (211), the cover plate body, the first plastic part (220) and the connection block (240); The dimension of the connection block (240) in the width direction (Y) is smaller than the dimension of the pole base (211) in the width direction (Y).

6. The battery assembly according to claim 5, characterized in that: The battery assembly further includes an insulating member (400); The insulating member (400) comprises a side portion (420) and a bottom portion (430) connected to each other, the side portion (420) being arranged between the cover plate body and the pole group (300), and the side portion (420) being arranged around the pole lug (100) and the cover plate pole; The bottom (430) is fitted between the pole base (211) and the pole group (300).

7. The battery assembly according to claim 6, characterized in that: The insulating member (400) further includes a top portion (410) connected to the side portion (420); The top portion (410) is disposed between the cover plate body and the pole lug (100), and the top portion (410) is disposed between the cover plate body and the cover plate pole; A gap is provided between the pole ear (100) and the second side of the pole base (211) for installing the top portion (410).

8. The battery assembly according to claim 6, characterized in that: The battery assembly also includes a sealing plate (500); The cover plate body and the insulating member (400) are both provided with through holes penetrating through the cover plate body; The through hole of the cover plate body and the through hole of the insulating member (400) both cover the pole lug (100), and the sealing plate (500) is welded to the inner wall of the through hole of the cover plate body.

9. A single cell battery, characterized in that: A battery assembly as claimed in any one of claims 1 to 8; The single cell comprises a first cover plate and a second cover plate, wherein the first cover plate and the second cover plate are respectively arranged at two ends of the electrode group (300); The first cover plate includes a first polarity pole, and the second cover plate includes a second polarity pole; The first polarity pole is the cover plate pole.

10. The single cell according to claim 9, characterized in that: The single cell further comprises an explosion-proof valve (600); The explosion-proof valve (600) is arranged on the second cover plate.

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