Battery

Abstract

This application provides a battery, including: a casing; a cover assembly connected to the casing and enclosing a receiving space; the cover assembly includes a cover plate and a plurality of terminals; an electrode assembly disposed within the receiving space, the electrode assembly including a bare cell and a plurality of adapter tabs; a plurality of tabs extending from the end face of the bare cell near the cover assembly, each tab being electrically connected to a corresponding adapter tab; the electrode assembly being electrically connected to a corresponding terminal in the cover assembly via the adapter tabs; wherein, the cover assembly further includes a lower insulating member disposed between the cover plate and the adapter tabs, the surface of the lower insulating member near the adapter tabs having a plurality of positioning protrusions protruding toward the adapter tabs, the plurality of positioning protrusions being located on the same side of the plurality of adapter tabs along the width direction of the cover plate, and each adapter tab corresponding to at least one positioning protrusion; the positioning protrusions are used to limit the position of the corresponding adapter tab in the width direction of the cover plate. The battery provided by this application helps to enhance the safety of a single battery cell.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more particularly to a battery. Background Technology

[0002] In the development of battery technology, besides improving the performance of individual battery cells, safety is also a crucial issue that cannot be ignored. If the safety of individual battery cells cannot be guaranteed, then those cells cannot be used. Therefore, how to enhance the safety of individual battery cells is a pressing technical problem that needs to be solved in battery technology. Utility Model Content

[0003] In view of this, the purpose of this application is to propose a battery that at least partially solves the problem of how to enhance the safety of individual battery cells.

[0004] Based on the above objectives, this application provides a battery, comprising: a housing; a cover assembly connected to the housing and enclosing it to form a receiving space; the cover assembly includes a cover plate and a plurality of electrode posts; the plurality of electrode posts are insulated from each other and connected to the cover plate, and arranged along the length direction of the cover plate; an electrode assembly disposed within the receiving space, the electrode assembly including a bare cell and a plurality of adapter tabs; a plurality of tabs are led out from the end face of the bare cell near the cover assembly, each tab being electrically connected to a corresponding adapter tab; the electrode assembly is connected to the cover assembly via the adapter tabs. The corresponding electrode post is electrically connected in the component; wherein, the cover plate assembly further includes a lower insulating member disposed between the cover plate and the adapter piece, the surface of the lower insulating member near the adapter piece is formed with a plurality of positioning protrusions protruding toward the adapter piece, the plurality of positioning protrusions are located on the same side of the plurality of adapter pieces along the width direction of the cover plate, and each adapter piece corresponds to at least one positioning protrusion; the positioning protrusions are used to limit the position of the corresponding adapter piece in the width direction of the cover plate when the electrode assembly and the cover plate assembly are electrically connected.

[0005] Optionally, each of the positioning protrusions includes a protruding end face near the bare cell, the protruding end face including two end edges spaced apart along the length direction of the cover plate; along the thickness direction of the cover plate, the projection of the electrode tab onto the lower insulator does not coincide with the end edges.

[0006] Optionally, the positioning protrusion is located on at least one side of the electrode tab along the length of the cover plate; or,

[0007] The positioning protrusions correspond one-to-one with the adapter pieces, the electrode covers the middle part of the protrusion end face, and both ends of the protrusion end face along the length direction of the cover plate extend beyond the edge of the corresponding electrode.

[0008] Optionally, the adapter includes a terminal connection portion and a tab connection portion electrically connected to the terminal connection portion along at least one side of the cover plate width direction; the terminal connection portion includes a first side close to the bare battery cell and a third side opposite to the first side; the tab connection portion includes a second side close to the bare battery cell; the adapter has a uniform thickness, and the second side is recessed relative to the first side towards the cover plate; the terminal is welded to the third side, and the tab is welded to the second side.

[0009] Optionally, the bare battery cell includes a first body and a second body arranged along the width direction of the cover plate, a plurality of tabs including positive tabs and negative tabs, and a plurality of adapter pieces including positive adapter pieces and negative adapter pieces; the electrode connection portion of each adapter piece is electrically connected to the tab connection portion on opposite sides along the width direction of the cover plate; one side of the tab connection portion of the positive adapter piece is electrically connected to the positive tab of the first body, and the other side of the tab connection portion is electrically connected to the positive tab of the second body; one side of the tab connection portion of the negative adapter piece is electrically connected to the negative tab of the first body, and the other side of the tab connection portion is electrically connected to the negative tab of the second body.

[0010] Optionally, the positioning protrusion does not extend beyond the second surface along the thickness direction of the cover plate; or,

[0011] The positioning protrusion includes a protruding end face close to the bare battery cell; along the thickness direction of the cover plate, the positioning protrusion extends beyond the second surface, and the straight-line distance between the protruding end face and the second surface is H1, where H1≤1mm.

[0012] Optionally, the electrode tab is welded to the corresponding electrode tab welding part to form an electrode tab weld mark; along the length direction of the cover plate, the positioning protrusion is located on at least one side of the corresponding electrode tab weld mark, and the minimum distance between the positioning protrusion and the electrode tab weld mark is L1, where L1≥2mm.

[0013] Optionally, the electrode lugs welded to the same electrode lug welding portion include n sheet-like structures stacked along the thickness direction of the cover plate, where n is 30 to 90; and / or,

[0014] Along the thickness direction of the cover plate, the distance between the second surface and the first surface is H2, the thickness of the electrode connected to the same electrode connection part is H3, and the ratio of H2 to H3 is 0.5 to 0.9.

[0015] Optionally, the positioning protrusion includes a contact side capable of contacting the corresponding adapter piece;

[0016] The projection of the adapter piece onto the positioning protrusion along the width direction of the cover plate coincides with the contact side, and the dimension of the overlapping portion along the length direction of the cover plate is L2, where L2 ≥ 3mm; and / or,

[0017] The positioning protrusion also includes a protruding end face near the bare battery cell, and a chamfer or arc surface for guidance is formed between the protruding end face and the contact side.

[0018] Optionally, the surface of the lower insulator near the bare cell is formed with a groove recessed toward the cover plate, and the adapter piece is at least partially located within the groove.

[0019] As can be seen from the above, the battery provided in this application has multiple positioning protrusions protruding towards the adapter piece on the surface of the lower insulating member near the adapter piece, and each adapter piece corresponds to at least one positioning protrusion. When the electrode assembly and the cover plate assembly are electrically connected, the positioning protrusions can be used as references to position each adapter piece in the electrode assembly along the width direction of the cover plate. At this time, each adapter piece of the electrode assembly is aligned with the corresponding terminal in the cover plate assembly along the width direction of the cover plate, and the actual contact position of each adapter piece with its corresponding terminal matches the preset contact position, which helps to form a reliable electrical connection between the adapter piece and the terminal, avoids internal short circuits in the battery, and helps to improve the reliability and safety of the battery.

[0020] Meanwhile, since multiple positioning protrusions are located on the same side of multiple adapter pieces along the width direction of the cover plate, when positioning the adapter pieces of the electrode assembly by means of positioning protrusions, the electrode assembly can move unidirectionally along the width direction of the cover plate to make multiple adapter pieces contact their respective positioning protrusions. This makes it easy for multiple adapter pieces to complete positioning along the width direction of the cover plate at the same time, which helps to reduce positioning difficulty, improve battery assembly efficiency, and facilitate mass production. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a partial cross-sectional schematic diagram of a battery with the first structure according to an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the welding of the electrode assembly and the cover plate assembly of the battery with the first structure according to an embodiment of this application.

[0024] Figure 3This is a partial cross-sectional schematic diagram of a battery with a second structure according to an embodiment of this application;

[0025] Figure 4a for Figure 3 An enlarged schematic diagram of part A in the middle;

[0026] Figure 4b for Figure 3 An enlarged schematic diagram of another structure in section A;

[0027] Figure 5 This is a schematic diagram of the welding of the electrode assembly and the cover plate assembly for a battery with a second structure according to an embodiment of this application.

[0028] Figure 6 for Figure 5 Enlarged schematic diagram of part B in the middle;

[0029] Figure 7 for Figure 5 An enlarged schematic diagram of section C;

[0030] Figure 8 This is a schematic diagram showing the cooperation between the adapter piece and the positioning protrusion of the battery with the second structure according to an embodiment of this application;

[0031] Figure 9 This is a schematic diagram of the adapter piece for a battery with a second structure according to an embodiment of this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. Shell; 110. Open end;

[0034] 200, cover plate assembly; 210, cover plate; 220, terminal post; 221, positive terminal post; 222, negative terminal post; 230, lower insulating component; 231, positioning protrusion; 2311, contact side; 2312, protruding end face; 23121, end edge; 232, groove;

[0035] 300. Accommodation space;

[0036] 400. Electrode assembly; 410. Bare cell; 411. Tab; 4111. Positive tab; 4112. Negative tab; 412. First body; 413. Second body; 420. Tab solder mark; 430. Adapter piece; 431. Terminal welding part; 4311. First side; 4312. Third side; 432. Tab welding part; 4321. Second side; 433. Positive adapter piece; 434. Negative adapter piece. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0038] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of this application.

[0039] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0040] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0041] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] Figure 1 A partial cross-sectional schematic diagram of the battery with the first structure is shown.

[0043] by Figure 1 Using the structure and orientation shown as an example, the battery may include a housing 100 and a cover assembly 200. The top of the housing 100 has an opening 110. The cover assembly 200 includes a cover 210, an electrode post 220 connected to the cover 210, and a lower insulator 230. The cover 210 is closed to the opening 110 so that the cover assembly 200 and the housing 100 can be closed to form a receiving space 300 for accommodating the electrode assembly 400. The lower insulator 230 is connected to the side of the cover 210 near the electrode assembly 400, and the bottom end of the electrode post 220 passes through the cover 210 and is exposed relative to the lower insulator 230.

[0044] The electrode assembly 400 located within the housing space 300 includes a bare cell 410 and an adapter plate 430. The tab 411 of the bare cell 410 is welded to the exposed part of the bottom end of the terminal post 220 through the adapter plate 430, thereby realizing the electrical connection between the bare cell 410 and the terminal post 220.

[0045] Figure 2A schematic diagram of the first type of battery being welded together with electrode assembly 400 and cover assembly 200 is shown.

[0046] like Figure 1 and Figure 2 The bare cell 410 of the electrode assembly 400 disposed within the accommodating space 300 may include multiple bodies, specifically, the number of bodies may be two, three, four or more.

[0047] by Figure 1 and Figure 2 The bare battery cell 410 shown is illustrated using a first body 412 and a second body 413 as an example. Figure 2 In the middle, the first main body 412 and the second main body 413 are in a flattened state that is far apart from each other. Figure 1 This is the converged state after the first body 412 and the second body 413 have been flipped. Each of the first body 412 and the second body 413 includes a wound or stacked body formed by an electrode and a separator. The electrode includes a positive electrode and a negative electrode, which are alternately arranged. The separator is used to isolate adjacent positive and negative electrodes. The electrode includes a metal substrate and an active material layer disposed on a portion of the substrate surface. The portion of the electrode without the active material layer is led out to form tabs 411. Tabs 411 include positive tabs 4111 led out from the positive electrode and negative tabs 4112 led out from the negative electrode. The positive tabs 4111 led out from the first body 412 and the positive tabs 4111 led out from the second body 413 can be welded to the same adapter piece 430, which can be called a positive adapter piece 433. The negative electrode tab 4112 led out from the first main body 412 and the negative electrode tab 4112 led out from the second main body 413 can be welded to another adapter piece 430, which can be called the negative electrode adapter piece 434. The positive electrode adapter piece 433 is then welded to the positive electrode post 221 in the electrode post 220, and the negative electrode adapter piece 434 is welded to the negative electrode post 222 in the electrode post 220.

[0048] It should be noted that during the battery assembly process, the tabs 411 of the bare cell 410 are first welded to the corresponding adapter piece 430 to form the electrode assembly 400, and the electrode assembly 400 is then welded to the corresponding terminal 220 in the cover plate assembly 200 through the adapter piece 430.

[0049] The applicant's research found that, such as Figure 2 Before the adapter piece 430 is welded to its corresponding pole piece 220, if the adapter piece 430 is along the width direction of the cover plate 210 (e.g., Figure 2If the position (in the Y direction) is not reliably positioned, the actual contact position between the adapter piece 430 and the end surface of the pole piece 220 will deviate from the preset contact position. However, since the pole piece 220 is blocked by the adapter piece 430 at this time, it is difficult to detect the above positional deviation. During welding, welding will still be performed at the preset contact position, which may result in the adapter piece 430 and the pole piece 220 failing to achieve effective welding in some positions after welding is completed, that is, a cold solder joint occurs.

[0050] When the terminal post 220 and the adapter piece 430 are poorly soldered, the electrical connection between the two may fail, leading to an internal open circuit in the battery, which will have an adverse effect on the safety and reliability of the battery.

[0051] To address the above issues, it is necessary to position the adapter piece 430 along the width direction of the cover plate 210 (hereinafter referred to as the width position) so that the relative position between the adapter piece 430 and the pole post 220 along the width direction of the cover plate 210 meets the design requirements, thereby ensuring the welding quality between the adapter piece 430 and the pole post 220.

[0052] In view of this, this embodiment provides a battery with a second structure.

[0053] Figure 3 A partial cross-sectional diagram of the second type of battery structure is shown. Figure 4a Showing Figure 3 An enlarged diagram of part A in the middle. Figure 5 A schematic diagram showing the second type of battery during the welding of electrode assembly 400 and cover plate assembly 200.

[0054] like Figure 3 , Figure 4a and Figure 5 In some embodiments, the battery includes: a housing 100; a cover assembly 200 connected to the housing 100 and enclosing to form a receiving space 300; the cover assembly 200 includes a cover 210 and a plurality of terminals 220; the plurality of terminals 220 are insulated from each other and connected to the cover 210 along the length direction of the cover 210 (e.g., ...). Figure 5The electrode assembly 400 is disposed within the receiving space 300. The electrode assembly 400 includes a bare cell 410 and multiple adapter plates 430. Multiple tabs 411 extend from the end face of the bare cell 410 near the cover plate assembly 200, and each tab 411 is electrically connected to a corresponding adapter plate 430. The electrode assembly 400 is electrically connected to a corresponding electrode post 220 in the cover plate assembly 200 through the adapter plates 430. The cover plate assembly 200 also includes a lower insulating member 230 disposed between the cover plate 210 and the adapter plates 430. Multiple positioning protrusions 231 protruding toward the adapter plates 430 are formed on the surface of the lower insulating member 230 near the adapter plates 430. The multiple positioning protrusions 231 are located on the multiple adapter plates 430 along the width direction of the cover plate 210 (e.g., in the X direction). Figure 5 On the same side of the Y direction in the electrode assembly 400, and each adapter piece 430 corresponds to at least one positioning protrusion 231; the positioning protrusion 231 is used to limit the position of the corresponding adapter piece 430 in the width direction of the cover plate 210 when the electrode assembly 400 is electrically connected to the cover plate assembly 200.

[0055] For example, among the plurality of terminals 220, at least one positive terminal 221 and at least one negative terminal 222 are included.

[0056] For example, multiple pole posts 220 are spaced apart along the length of the cover plate 210, and each pole post 220 is provided with an insulating element between itself and the cover plate 210 to ensure that each pole post 220 is insulated from the cover plate 210.

[0057] For example, the cover plate 210 and the housing 100 can be made of aluminum, steel, etc. The cover plate 210 and the housing 100 can be connected by means of adhesive, riveting, welding, etc. For example, the cover plate 210 and the housing 100 are made of aluminum, and the cover plate 210 and the housing 100 are welded together.

[0058] For example, the lower insulating member 230 and the cover plate 210 can be connected by means of adhesive bonding or heat pressing.

[0059] For example, the positioning protrusion 231 and the lower insulating member 230 can be connected by means of adhesive bonding, hot pressing or integral molding.

[0060] by Figure 5 Taking the structure and orientation shown as an example, the battery includes an upper adapter piece 430 and a lower adapter piece 430. Figure 5In the structure shown, the positioning protrusion 231 corresponding to the upper adapter piece 430 is located on the right side of the adapter piece 430, and the positioning protrusion 231 corresponding to the lower adapter piece 430 is also located on the right side of the adapter piece 430. As can be seen from the foregoing, when the electrode assembly 400 is electrically connected to the cover plate assembly 200, multiple adapter pieces 430 and the bare battery cell 410 are already connected as a whole (which can be called a pre-connection structure). However, since the tab 411 can be bent along the width direction of the cover plate 210, once the width position of the upper adapter piece 430 is positioned, if the width position of the lower adapter piece 430 is not also limited, the lower adapter piece 430 can still move along the width direction of the cover plate 210. In other words, in the same electrode assembly 400, each adapter piece 430 needs to be positioned along the width direction of the cover plate 210.

[0061] Therefore, in this embodiment, before the electrode assembly 400 is electrically connected to the cover plate assembly 200, the electrode assembly 400 and the cover plate assembly 200 can be roughly positioned. At this time, each adapter piece 430 in the electrode assembly 400 is aligned along the thickness direction of the cover plate 210 (e.g., ...). Figure 3 The Z-direction of the plate 430 is close to the pole post 220 and the lower insulator 230, and each adapter piece 430 is close to its corresponding pole post 220 along the width direction of the cover plate 210.

[0062] Next, adjust the width position of the electrode assembly 400. At this time, all the positioning protrusions 231 and transition pieces 430 on the lower insulating member 230 are visible. When adjusting the position of the electrode assembly 400, each transition piece 430 needs to be brought close to or even in contact with its corresponding positioning protrusion 231 so that each transition piece 430 is positioned along the width direction of the cover plate 210 by the multiple positioning protrusions 231. After each transition piece 430 is aligned with its corresponding pole post 220 under the action of the positioning protrusion 231, the transition pieces 430 and the pole post 220 are electrically connected.

[0063] The battery provided in this embodiment has multiple positioning protrusions 231 formed on the surface of the lower insulating member 230 near the adapter piece 430, protruding towards the adapter piece 430, and each adapter piece 430 corresponds to at least one positioning protrusion 231. When the electrode assembly 400 is electrically connected to the cover plate assembly 200, the positioning protrusions 231 can be used as references to position each adapter piece 430 in the electrode assembly 400 along the width direction of the cover plate 210. At this time, each adapter piece 430 of the electrode assembly 400 is aligned with the corresponding terminal post 220 in the cover plate assembly 200 along the width direction of the cover plate 210, and the actual contact position of each adapter piece 430 with its corresponding terminal post 220 matches the preset contact position, which helps to form a reliable electrical connection between the adapter piece 430 and the terminal post 220, avoids internal short circuits in the battery, and helps to improve the reliability and safety of the battery.

[0064] Meanwhile, since multiple positioning protrusions 231 are located on the same side of multiple adapter pieces 430 along the width direction of the cover plate 210, when positioning the adapter pieces 430 of the electrode assembly 400 by means of positioning protrusions 231, the electrode assembly 400 can move unidirectionally along the width direction of the cover plate 210 to make multiple adapter pieces 430 contact their respective positioning protrusions 231, which makes it easy for multiple adapter pieces 430 to complete positioning along the width direction of the cover plate 210 at the same time, which helps to reduce positioning difficulty, improve battery assembly efficiency, and is beneficial for mass production.

[0065] Figure 6 Showing Figure 5 An enlarged diagram of part B in the middle. Figure 7 Showing Figure 5 An enlarged schematic diagram of section C.

[0066] like Figure 4a , Figure 6 and Figure 7 In some embodiments, each positioning protrusion 231 includes a protruding end face 2312 near the bare cell 410, and the protruding end face 2312 includes two end edges 23121 spaced apart along the length direction of the cover plate 210; along the thickness direction of the cover plate 210, the projection of the tab 411 on the lower insulating member 230 does not coincide with the end edge 23121.

[0067] It should be noted that the protruding end face 2312 extends along the length of the cover plate 210, and the two end edges 23121 correspond to the two ends of the positioning protrusion 231 along the length of the cover plate 210.

[0068] Understandably, sharp structures (e.g., sharp edges or corners) may appear at the end edge 23121. The tab 411 includes multiple stacked sheet structures, each with a small thickness. If a sharp structure comes into contact with a sheet structure in the tab 411, it may cause the sheet structure to be scratched by the sharp structure, which will have an adverse effect on the electrical connection between the tab 411 and the adapter 430, resulting in lower battery reliability and safety.

[0069] To avoid the above problems, this embodiment sets the end edge 23121 and the tab 411 in a staggered manner. Since the projection of the tab 411 along the thickness direction of the cover plate 210 does not coincide with the end edge 23121, the tab 411 will not come into contact with the end edge 23121. This can effectively prevent the tab 411 from being scratched by the end edge 23121, ensuring that the tab 411 and the adapter piece 430 can form a reliable electrical connection, which helps to improve the reliability and safety of the battery.

[0070] Regarding the specific setting method of positioning protrusion 231, such as Figure 6 In some embodiments, the positioning protrusion 231 is located on at least one side of the tab 411 along the length of the cover plate 210.

[0071] by Figure 6 The structure and orientation shown are used as examples for explanation. Figure 6 The adapter piece 430 has a positioning protrusion 231 on its right side, and the positioning protrusion 231 is located above the tab 411 connected to the adapter piece 430. The positioning protrusion 231 is completely exposed relative to the tab 411, which ensures that neither of the two end edges 23121 of the positioning protrusion 231 is covered by the tab 411, nor does it come into contact with the tab 411.

[0072] In addition to the above-mentioned settings, the positioning protrusion 231 can also have other settings, such as... Figure 7 In some embodiments, the positioning protrusion 231 corresponds one-to-one with the adapter piece 430, the tab 411 covers the middle part of the protrusion end face 2312, and both ends of the protrusion end face 2312 along the length direction of the cover plate 210 extend beyond the edge of the corresponding tab 411.

[0073] by Figure 7 The structure and orientation shown are used as examples for explanation. Figure 7The adapter piece 430 has a positioning protrusion 231 on its right side, with the middle part of the positioning protrusion 231 covered by the tab 411. The upper end of the positioning protrusion 231 extends beyond the upper edge of the tab 411, and the lower end of the positioning protrusion 231 extends beyond the lower edge of the tab 411. At this time, for the protruding end face 2312 of the positioning protrusion 231, its upper end edge 23121 is above the upper edge of the tab 411, and its lower end edge 23121 is below the lower edge of the tab 411. This ensures that neither end edge 23121 of the positioning protrusion 231 is covered by the tab 411, nor does it come into contact with the tab 411.

[0074] Figure 9 A schematic diagram of the adapter piece 430 for the second type of battery structure is shown.

[0075] like Figure 3 and Figure 4a In some embodiments, the adapter plate 430 includes a terminal connection portion 431 and a tab connection portion 432 electrically connected to the terminal connection portion 431 along at least one side of the cover plate 210 in the width direction; the terminal connection portion 431 includes a first surface 4311 near the bare cell 410 and a third surface 4312 opposite to the first surface 4311; the tab connection portion 432 includes a second surface 4321 near the bare cell 410; the adapter plate 430 has a uniform thickness, and the second surface 4321 is recessed toward the cover plate 210 relative to the first surface 4311; the terminal 220 is welded to the third surface 4312, and the tab 411 is welded to the second surface 4321.

[0076] For example, the electrode post connection part 431 and the electrode tab connection part 432 can be electrically connected by means of integral molding, welding, conductive adhesive bonding or plugging.

[0077] by Figure 4a Taking the structure and orientation shown as an example, the bottom surface of the pole post connector 431 is the first surface 4311, the top surface of the pole post connector 431 is the third surface 4312, and the bottom surface of the tab connector 432 is the second surface 4321. When the thickness of the pole post connector 431 is the same as the thickness of the tab connector 432, if the second surface 4321 is located above the first surface 4311 (that is, the second surface 4321 is recessed towards the cover plate 210 relative to the first surface 4311), then the tab connector 432 and the pole post connector 431 are misaligned along the thickness direction of the cover plate 210, that is, the top surface of the tab connector 432 is also located above the third surface 4312. At this time, when only one side of the pole post connector 431 is connected to the tab connector 432, the adapter piece 430 is Z-shaped; when the opposite sides of the pole post connector 431 are respectively connected to the tab connector 432, the adapter piece 430 is Z-shaped, such as... Figure 9 .

[0078] Still with Figure 4a Taking the structure and orientation shown as an example, when the pole post 220 is welded to the adapter piece 430, heat will radiate outward. In order to avoid the lower insulating part 230 from being deformed by heat, the pole post 220 can be designed to protrude a certain height from the bottom surface of the lower insulating part 230. This way, a large gap can be maintained between the pole post connection part 431 and the lower insulating part 230 in the longitudinal direction, reducing the heat transferred to the lower insulating part 230.

[0079] However, the inventors discovered that if the tab connection 432 and the pole connection 431 are aligned along the thickness direction of the cover plate 210 (i.e., the second surface 4321 is flush with the first surface 4311), then there will be a large gap between the top surface of the tab connection 432 and the bottom surface of the lower insulating member 230, which will result in wasted space.

[0080] To address the aforementioned issues, this embodiment places the tab connection portion 432 above the first surface 4311. This allows the distance between the top surface of the tab connection portion 432 and the bottom surface of the lower insulating member 230 to be smaller than the distance between the third surface 4312 and the bottom surface of the lower insulating member 230. This increases the space below the tab connection portion 432, enabling the placement of larger bare cells 410 within the accommodating space 300. This helps improve the space utilization of the accommodating space 300 and the energy density of the battery.

[0081] like Figure 3 and Figure 5 In some embodiments, the bare cell 410 includes a first body 412 and a second body 413 arranged along the width direction of the cover plate 210, a plurality of tabs 411 including a positive tab 4111 and a negative tab 4112, and a plurality of adapter pieces 430 including a positive adapter piece 433 and a negative adapter piece 434; the terminal connection portion 431 of each adapter piece 430 is electrically connected to a tab connection portion 432 on opposite sides along the width direction of the cover plate 210; one side tab connection portion 432 of the positive adapter piece 433 is electrically connected to the positive tab 4111 of the first body 412, and the other side tab connection portion 432 is electrically connected to the positive tab 4111 of the second body 413; one side tab connection portion 432 of the negative adapter piece 434 is electrically connected to the negative tab 4112 of the first body 412, and the other side tab connection portion 432 is electrically connected to the negative tab 4112 of the second body 413.

[0082] by Figure 5 The structure and orientation shown are illustrated below. In this embodiment, when the first body 412 and the second body 413 are flattened, the first body 412 is located on the left side of the cover plate assembly 200, and the second body 413 is located on the right side of the cover plate assembly 200; the two are symmetrically arranged relative to the cover plate assembly 200. (Combined with...) Figure 3In each adapter piece 430, a tab connection part 432 is connected to the left side of the terminal connection part 431, and another tab connection part 432 is connected to the right side. The positive tab 4111 of the first main body 412 is electrically connected to the tab connection part 432 on the left side of the positive adapter piece 433, and the negative tab 4112 of the second main body 413 is electrically connected to the tab connection part 432 on the right side of the positive adapter piece 433. The electrical connection method between the negative tab 4112 and the negative adapter piece 434 is similar and will not be described in detail here.

[0083] In this embodiment, since the tab 411 can be electrically connected to the tab connection portion 432 on the same side, it helps to shorten the extension length of the tab 411, reduce material costs, and also helps to reduce the risk of internal short circuits caused by the tab 411 contacting the electrode plates inside the main body (including the first main body 412 or the second main body 413) when bending due to its long extension length. At the same time, through the structural design of this embodiment, when the electrode assembly 400 is installed into the housing 100, it is easy to make the electrode assembly 400 centrally symmetrically inserted into the housing.

[0084] Figure 4b Showing Figure 3 An enlarged schematic diagram of another structure in part A.

[0085] like Figure 4b In some embodiments, the positioning protrusion 231 does not extend beyond the second surface 4321 along the thickness direction of the cover plate 210.

[0086] For example, the protruding end face 2312 of the positioning protrusion 231 can be flush with the second surface 4321; or, along the thickness direction of the cover plate 210, the positioning protrusion 231 can be located on the side of the second surface 4321 near the cover plate 210.

[0087] by Figure 4b Taking the structure and orientation shown as an example, the tab 411 is connected to the second surface 4321. If the positioning protrusion 231 extends beyond the second surface 4321, it may exert a force on the tab 411, causing it to move away from the second surface 4321. Due to this force, on the one hand, the tab 411 may limit the position of the adapter piece 430, making it difficult for the adapter piece 430 and the end face of the pole post 220 to fit tightly together, resulting in a poor solder joint between the adapter piece 430 and the pole post 220; on the other hand, it may also cause the tab 411 to tear under pressure.

[0088] To avoid the aforementioned problems, this embodiment designs the positioning protrusion 231 to not extend beyond the second surface 4321 along the thickness direction of the cover plate 210, combined with... Figure 4bSince the tab 411 is located below the second surface 4321, if the positioning protrusion 231 does not extend beyond the second surface 4321, then the positioning protrusion 231 will not contact the tab 411, nor will it exert the aforementioned force on the tab 411. This ensures that the adapter piece 430 and the end face of the terminal 220 are tightly fitted, ensuring that the terminal 220 and the adapter piece 430 can form a reliable electrical connection. It also prevents the tab 411 from tearing, ensuring that the tab 411 and the adapter piece 430 can form a reliable electrical connection, which helps to improve the reliability and safety of the battery.

[0089] like Figure 4a In some embodiments, the positioning protrusion 231 includes a protruding end face 2312 close to the bare cell 410; along the thickness direction of the cover plate 210, the positioning protrusion 231 extends beyond the second surface 4321, and the straight-line distance between the protruding end face 2312 and the second surface 4321 is H1, where H1≤1mm.

[0090] For example, H1 can be 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm or 1mm.

[0091] If H1 is too large, the risk of the positioning protrusion 231 contacting the tab 411 and exerting a force on the tab 411 to drive it away from the second surface 4321 will also be too high, which may lead to poor soldering between the adapter piece 430 and the pole post 220 or tearing of the tab 411 under pressure. When the thickness of the adapter piece 430 is small and the protrusion height of the positioning protrusion 231 along the thickness direction of the cover plate 210 is too small, the contact area between the positioning protrusion 231 and the adapter piece 430 will be too small, making it difficult to stably and effectively position the adapter piece 430 through the positioning protrusion 231.

[0092] To avoid the above problems, this embodiment designs H1 to be ≤ 1mm, which can ensure that the positioning protrusion 231 can stably and effectively position the adapter piece 430, ensure that the adapter piece 430 and the end face of the terminal 220 are tightly fitted, and that the terminal 220 and the adapter piece 430 can form a reliable electrical connection. It can also prevent the tab 411 from tearing, and ensure that the tab 411 and the adapter piece 430 can form a reliable electrical connection, which helps to improve the reliability and safety of the battery.

[0093] like Figure 6 In some embodiments, the tab 411 is welded to the corresponding tab welding portion 432 to form a tab weld mark 420; along the length direction of the cover plate 210, the positioning protrusion 231 is located on at least one side of the corresponding tab weld mark 420, and the minimum distance between the positioning protrusion 231 and the tab weld mark 420 is L1, where L1 ≥ 2 mm.

[0094] For example, L1 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm or 5mm.

[0095] Understandably, the area of ​​tab 411 that is close to tab solder mark 420 will maintain a close distance to the second surface 4321 (along the thickness direction of cover plate 210) under the fixing effect of tab solder mark 420. Combined with... Figure 4a When the positioning protrusion 231 protrudes from the second surface 4311 toward the bare cell 410, and the positioning protrusion 231 is too close to the tab solder mark 420, the positioning protrusion 231 will contact the area of ​​the tab 411 that is close to the tab solder mark 420, and exert a force on that area of ​​the tab 411 to drive it away from the second surface 4321. Under the influence of this force, on the one hand, it may be difficult for the end faces of the adapter piece 430 and the terminal post 220 to fit tightly, resulting in a poor solder joint between the adapter piece 430 and the terminal post 220; on the other hand, it may also cause the aforementioned area of ​​the tab 411 to tear under the combined action of the tab solder mark 420 and the positioning protrusion 231.

[0096] To avoid the aforementioned problems, this embodiment designs L1 to be ≥ 2mm. Even if the positioning protrusion 231 contacts the tab 411, it will contact an area of ​​the tab 411 that is farther away from the tab solder mark 420. This area of ​​the tab 411 experiences less fixing force from the tab solder mark 420. When the positioning protrusion 231 applies force to this area of ​​the tab 411, this area of ​​the tab 411 can release the force through bending deformation. This ensures that the adapter piece 430 and the end face of the terminal 220 are tightly fitted, ensuring a reliable electrical connection between the terminal 220 and the adapter piece 430. It also prevents the tab 411 from tearing, ensuring a reliable electrical connection between the tab 411 and the adapter piece 430, thus improving the reliability and safety of the battery.

[0097] like Figure 4a In some embodiments, the tabs 411 welded to the same tab welding portion 432 include n sheet-like structures stacked along the thickness direction of the cover plate 210, where n is 30 to 90.

[0098] For example, n can be 30, 36, 40, 48, 50, 54, 60, 66, 70, 72, 80, 88 or 90.

[0099] Taking the first body 412 as an example, the first body 412 includes a multilayer structure formed by multiple positive electrode plates, multiple negative electrode plates and multiple separators. Correspondingly, at least some of the positive electrode plates in the first body 412 will form sheet-like structures led out from the first body 412. These sheet-like structures can be stacked to form a positive electrode tab 4111; at least some of the negative electrode plates will form sheet-like structures led out from the first body 412. These sheet-like structures can be stacked to form a negative electrode tab 4112.

[0100] If there are too many stacked sheet-like structures in the same tab 411 (positive tab 4111 or negative tab 4112), stress concentration may occur at the bending point of the tab 411, potentially leading to tearing of the tab 411. If there are too few stacked sheet-like structures in the same tab 411, the local current density of the tab 411 may be too high, resulting in severe heating. It may also cause the tab 411 to be unable to effectively buffer the internal stress generated by the expansion of the first body 412, leading to diaphragm rupture.

[0101] To avoid the above problems, this embodiment designs n to be 30 to 90, which can reduce stress concentration at the bending point of the tab 411 and effectively buffer the internal stress generated by the expansion of the first body 412, preventing damage to the tab 411 and the separator; at the same time, it also helps to control the current density of the tab 411 at a reasonable level, which helps to improve the cell performance, reliability and safety of the battery.

[0102] like Figure 4b In some embodiments, along the thickness direction of the cover plate 210, the distance between the second surface 4321 and the first surface 4311 is H2, the thickness of the tab 411 connected to the same tab connection portion 432 is H3, and the ratio of H2 to H3 is 0.5 to 0.9.

[0103] For example, the ratio of H2 to H3 can be 0.5, 0.6, 0.7, 0.8 or 0.9.

[0104] If the ratio of H2 to H3 is too large, it may indicate that the height difference between the first surface 4311 and the second surface 4321 is too large. Since the edge of the second surface 4321 is close to the tab solder mark 420, this may cause the tab 411 to tear under the pressure of the edge of the second surface 4321. Alternatively, if the ratio of H2 to H3 is too large, it may also indicate that the thickness of the tab 411 is too small. This will not only cause the resistance of the tab 411 to be too large, affecting the charging and discharging efficiency of the battery, but may also cause the tab 411 to be prone to breakage, thereby causing a short circuit inside the battery. If the ratio of H2 to H3 is too small, it may indicate that the height difference between the first surface 4311 and the second surface 4321 is too small. In this case, the effect of the second surface 4321 being located above the first surface 4311 in improving the space utilization of the accommodating space 300 will not be obvious. Alternatively, a small ratio of H2 to H3 may also indicate that the thickness of the tab 411 is too large. When the current passes through the tab 411, the heat generated is difficult to dissipate effectively, which may cause the local temperature to rise too much or even lead to thermal runaway. The tab 411 with excessive thickness is also prone to stress concentration when squeezed by the edge of the second surface 4321, which accelerates the fatigue damage of the tab 411.

[0105] To avoid the aforementioned problems, this embodiment designs the ratio of H2 to H3 to be between 0.5 and 0.9. This prevents tearing or stress concentration in the tab 411, helping to improve electrode reliability and electrical performance such as charge / discharge efficiency. Simultaneously, it ensures that the tab 411 can effectively dissipate heat when current flows, reducing the risk of thermal runaway.

[0106] like Figure 6 and Figure 7 In some embodiments, the positioning protrusion 231 includes a contact side 2311 that can contact the corresponding adapter piece 430; the projection of the adapter piece 430 on the positioning protrusion 231 along the width direction of the cover plate 210 coincides with the contact side 2311, and the dimension of the overlapping part along the length direction of the cover plate 210 is L2, where L2≥3mm.

[0107] For example, L2 can be 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0108] If L2 is too small, the contact area between the positioning protrusion 231 and the adapter piece 430 will be too small, making it difficult to stably and effectively position the adapter piece 430 through the positioning protrusion 231.

[0109] To avoid the above problems, in this embodiment, L2 is designed to be L2≥3mm, which can ensure that the adapter piece 430 can be stably and effectively positioned by the positioning protrusion 231, and ensure that the terminal post 220 can form a reliable electrical connection with the adapter piece 430, which helps to improve the reliability and safety of the battery.

[0110] Figure 8 A schematic diagram showing the interaction between the adapter piece 430 and the positioning protrusion 231 of the battery with the second structure is shown.

[0111] like Figure 4a In some embodiments, the positioning protrusion 231 further includes a protruding end face 2312 near the bare cell 410, and a guide slope is formed between the protruding end face 2312 and the contact side face 2311.

[0112] When connecting the cover plate assembly 200 to the electrode assembly 400, the cover plate assembly 200 can be first placed in reverse and flat. At this time, the positioning protrusion 231 protrudes upward, as shown. Figure 8 Then, the flattened electrode assembly 400 is placed from top to bottom. During the placement of the electrode assembly 400, it is necessary to align the adapter piece 430 with the contact side 2311 of the positioning protrusion 231. When the contact side 2311 is perpendicular to the bottom surface of the lower insulating member 230, the orthographic projection of the contact side 2311 along the thickness direction of the cover plate 210 is a straight line, which makes it difficult to align the adapter piece 430 with the contact side 2311.

[0113] To solve the above problems, this embodiment provides an inclined surface between the contact side 2311 and the protruding end face 2312. Since the orthographic projection of the inclined surface along the thickness direction of the cover plate 210 has a certain area, the difficulty of aligning the adapter piece 430 with the inclined surface can be reduced. When the edge of the adapter piece 430 contacts the inclined surface, it can slide down along the inclined surface. Since the contact side 2311 is connected to the lower part of the inclined surface, the adapter piece 430 can automatically contact the contact side 2311 after sliding down along the inclined surface, thereby completing the positioning of the adapter piece 430 by the positioning protrusion 231.

[0114] like Figure 4b In some embodiments, a guiding arc surface is formed between the protruding end face 2312 and the contact side face 2311.

[0115] It should be noted that the beneficial effects of the curved surface used for guidance in this embodiment are similar to those of the inclined surface used for guidance described above, and will not be repeated here.

[0116] like Figure 3 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the surface of the lower insulator 230 near the bare cell 410 is formed with a groove 232 recessed toward the cover plate 210, and the adapter piece 430 is at least partially located in the groove 232.

[0117] For example, the projection of the adapter piece 430 along the thickness direction of the cover plate 210 onto the lower insulating member 230 coincides with or is located inside the groove 232.

[0118] The portion of the lower insulating member 230 with the groove 232 has a smaller thickness. When the adapter piece 430 is at least partially located in the groove 232, this portion of the adapter piece 430 coincides with the lower insulating member 230 along the thickness direction of the cover plate 210. This can reduce the space occupied by the adapter piece 430 in the accommodating space 300 below the lower insulating member 230, so that a larger bare cell 410 can be installed in the accommodating space 300, which helps to improve the space utilization of the accommodating space 300 and the energy density of the battery.

[0119] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0120] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0121] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0122] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0123] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0124] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A battery, characterized by, include: case; A cover plate assembly is connected to the housing and encloses it to form a receiving space; the cover plate assembly includes a cover plate and multiple pole posts; The plurality of pole posts are connected to the cover plate insulated from each other and are arranged along the length of the cover plate; An electrode assembly is disposed within the receiving space. The electrode assembly includes a bare battery cell and multiple adapter plates. Multiple tabs extend from the end face of the bare battery cell near the cover plate assembly, and each tab is electrically connected to a corresponding adapter plate. The electrode assembly is electrically connected to a corresponding electrode post in the cover plate assembly via the adapter plates. The cover plate assembly further includes a lower insulating member disposed between the cover plate and the adapter piece. The surface of the lower insulating member near the adapter piece is formed with a plurality of positioning protrusions protruding toward the adapter piece. The plurality of positioning protrusions are located on the same side of the plurality of adapter pieces along the width direction of the cover plate, and each adapter piece corresponds to at least one of the positioning protrusions. The positioning protrusion is used to limit the position of the corresponding adapter piece in the width direction of the cover plate when the electrode assembly and the cover plate assembly are electrically connected.

2. The battery of claim 1, wherein, Each of the positioning protrusions includes a protruding end face near the bare battery cell, and the protruding end face includes two end edges spaced apart along the length direction of the cover plate; Along the thickness direction of the cover plate, the projection of the electrode tab onto the lower insulating member does not coincide with the end edge.

3. The battery of claim 2, wherein, The positioning protrusion is located on at least one side of the electrode lug along the length of the cover plate; or, The positioning protrusions correspond one-to-one with the adapter pieces, the electrode covers the middle part of the protrusion end face, and both ends of the protrusion end face along the length direction of the cover plate extend beyond the edge of the corresponding electrode.

4. The battery of claim 1, wherein, The adapter includes a pole connection portion and a tab connection portion electrically connected to the pole connection portion along at least one side of the cover plate width direction; The electrode connection portion includes a first side close to the bare battery cell and a third side opposite to the first side; the electrode tab connection portion includes a second side close to the bare battery cell; the adapter piece has a uniform thickness, and the second side is recessed relative to the first side towards the cover plate; The pole post is welded to the third surface, and the tab is welded to the second surface.

5. The battery of claim 4, wherein, The bare battery cell includes a first body and a second body arranged along the width direction of the cover plate, a plurality of tabs including positive tabs and negative tabs, and a plurality of adapter pieces including positive adapter pieces and negative adapter pieces; the electrode connection portion of each adapter piece is electrically connected to the tab connection portion on opposite sides along the width direction of the cover plate; One side of the positive electrode adapter is electrically connected to the positive electrode of the first main body, and the other side is electrically connected to the positive electrode of the second main body. One side of the negative electrode adapter is electrically connected to the negative electrode of the first main body, and the other side is electrically connected to the negative electrode of the second main body.

6. The battery of claim 4, wherein, The positioning protrusion does not extend beyond the second surface along the thickness direction of the cover plate; or... The positioning protrusion includes a protruding end face close to the bare battery cell; along the thickness direction of the cover plate, the positioning protrusion extends beyond the second surface, and the straight-line distance between the protruding end face and the second surface is H1, where H1≤1mm.

7. The battery of claim 4, wherein, The electrode tab is welded to the corresponding electrode tab welding part to form an electrode tab weld mark; along the length direction of the cover plate, the positioning protrusion is located on at least one side of the corresponding electrode tab weld mark, and the minimum distance between the positioning protrusion and the electrode tab weld mark is L1, where L1≥2mm.

8. The battery of claim 4, wherein, The electrode lugs welded to the same electrode lug welding portion comprise n sheet-like structures stacked along the thickness direction of the cover plate, where n is 30 to 90; and / or, Along the thickness direction of the cover plate, the distance between the second surface and the first surface is H2, the thickness of the electrode connected to the same electrode connection part is H3, and the ratio of H2 to H3 is 0.5 to 0.

9.

9. The battery of claim 1, wherein, The positioning protrusion includes a contact side that can contact the corresponding adapter piece; The projection of the adapter piece onto the positioning protrusion along the width direction of the cover plate coincides with the contact side, and the dimension of the overlapping portion along the length direction of the cover plate is L2, where L2 ≥ 3mm; and / or, The positioning protrusion also includes a protruding end face near the bare battery cell, and a chamfer or arc surface for guidance is formed between the protruding end face and the contact side.

10. The battery of claim 1, wherein, The surface of the lower insulator near the bare cell has a groove recessed toward the cover plate, and the adapter piece is at least partially located within the groove.

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