Battery

Abstract

This application provides a battery, comprising: 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; the plurality of terminals are insulated from each other and arranged along the length 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 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 positioning protrusion protruding toward the adapter tabs; the positioning protrusion is located on one side of one of the adapter tabs along the length 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 in particular 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 a receiving space; the cover assembly including a cover plate and a plurality of terminals; the plurality of terminals 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 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 positioning protrusion protruding toward the adapter tabs; the positioning protrusion is located on one side of one of the adapter tabs along the length direction of the cover plate; the positioning protrusion is used to limit the position of the corresponding adapter tab in the length direction of the cover plate when the electrode assembly is electrically connected to the cover assembly.

[0005] Optionally, the cover plate is provided with an injection hole that extends through the thickness direction of the cover plate; along the length direction of the cover plate, the injection hole is close to one of the plurality of adapter pieces, and the positioning protrusion is located between the injection hole and the adapter piece that is close to the injection hole.

[0006] 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.

[0007] 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.

[0008] Optionally, in the adapter piece corresponding to the positioning protrusion, a positioning groove is formed on the sidewall near the positioning protrusion at the pole connection portion; the positioning groove is recessed towards the center of the adapter piece along the length direction of the cover plate and extends through the adapter piece along the thickness direction of the cover plate; the positioning protrusion is at least partially located within the positioning groove.

[0009] Optionally, the positioning groove includes a groove bottom near the center of the adapter piece, and the positioning protrusion includes a contact side that can contact the groove bottom, the contact side being arranged parallel to the groove bottom.

[0010] Optionally, the positioning protrusion 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.

[0011] Optionally, the electrode tab is welded to the electrode tab connection portion to form an electrode tab weld mark, and the minimum distance between the positioning protrusion and the electrode tab weld mark along the width direction of the cover plate is L1, where L1 > 5mm; and / or,

[0012] The electrode connected to the same electrode connection portion includes n sheet-like structures stacked along the thickness direction of the cover plate, where n is 30 to 90.

[0013] Optionally, along the thickness direction of the cover plate, the distance between the second surface and the first surface is H1, the thickness of the electrode connected to the same electrode connection portion is H2, and the ratio of H1 to H2 is 0.5 to 0.9.

[0014] 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.

[0015] As can be seen from the above, the battery provided in this application has a positioning protrusion protruding towards the adapter piece on the surface of the lower insulating member near the adapter piece. When the electrode assembly and the cover plate assembly are electrically connected, the positioning protrusion can be used as a reference to position one of the adapter pieces in the electrode assembly along the length of the cover plate. After the adapter piece is positioned, since the relative positions of the other adapter pieces in the electrode assembly with the adapter piece along the length of the cover plate are relatively fixed, the positions of the other adapter pieces along the length of the cover plate are also automatically positioned. At this time, each adapter piece of the electrode assembly is aligned with the corresponding terminal in the cover plate assembly along the length of the cover plate, and the actual contact position of each adapter piece with its corresponding terminal matches the preset contact position. This 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.

[0016] Meanwhile, in actual production, the spacing between adjacent adapter pieces in the electrode assembly along the length of the cover plate may have errors that meet process requirements. If a positioning protrusion is provided for each adapter piece, the positioning protrusion may forcibly correct the aforementioned positional error of the adapter piece when positioning each adapter piece. The force exerted by the positioning protrusion on the adapter piece may be transmitted to the tab, causing the tab to tear. In this application, multiple adapter pieces are positioned using only one positioning protrusion, which allows for positional errors between adjacent adapter pieces along the length of the cover plate that meet process requirements. While ensuring that the adapter pieces can achieve reliable electrical connection with the corresponding terminals, it can also prevent tab tearing, thus helping to improve the reliability and safety of the battery. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a partial cross-sectional schematic diagram of a battery with the first structure according to an embodiment of this application;

[0019] 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.

[0020] Figure 3 This is a partial cross-sectional schematic diagram of a battery with a second structure according to an embodiment of this application;

[0021] Figure 4 for Figure 3 An enlarged schematic diagram of part A in the middle;

[0022] 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.

[0023] Figure 6 for Figure 5 Enlarged schematic diagram of part B in the middle;

[0024] Figure 7 This is a schematic diagram of the adapter piece for a battery with a second structure according to an embodiment of this application;

[0025] 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;

[0026] Figure 9 for Figure 8 A partial cross-sectional schematic diagram of a structure with a CC section in the middle;

[0027] Figure 10 for Figure 8 Partial cross-sectional schematic diagrams of two structures in the CC section.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100. Shell; 110. Open end;

[0030] 200, cover plate assembly; 210, cover plate; 211, injection hole; 220, electrode post; 221, positive electrode post; 222, negative electrode post; 230, lower insulating component; 231, positioning protrusion; 2311, contact side; 2312, protruding end face; 232, groove;

[0031] 300. Accommodation space;

[0032] 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 connection part; 4311. First side; 4312. Third side; 432. Tab connection part; 4321. Second side; 433. Positive adapter piece; 434. Negative adapter piece; 435. Positioning groove; 4351. Groove bottom; 4352. Groove wall. Detailed Implementation

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Figure 1 A partial cross-sectional schematic diagram of the battery with the first structure is shown.

[0039] 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.

[0040] 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.

[0041] Figure 2A schematic diagram of the first type of battery being welded together with electrode assembly 400 and cover assembly 200 is shown.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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 length of the cover plate 210 (e.g., Figure 2If the position (in the X 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, that is, a cold solder joint occurs.

[0046] 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.

[0047] To address the above issues, it is necessary to position the adapter piece 430 along the length of the cover plate 210 (hereinafter referred to as the longitudinal position) so that the relative position between the adapter piece 430 and the pole post 220 along the length of the cover plate 210 meets the design requirements, thereby ensuring the welding quality between the adapter piece 430 and the pole post 220.

[0048] In view of this, this embodiment provides a battery with a second structure.

[0049] Figure 3 A partial cross-sectional diagram of the second type of battery structure is shown. Figure 4 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.

[0050] like Figure 3 , Figure 4 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 arranged in the X direction; it is disposed within the receiving space 300 and includes a bare cell 410 and a plurality of adapter pieces 430; a plurality of tabs 411 are led out 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 piece 430; the electrode assembly 400 is electrically connected to a corresponding electrode post 220 in the cover plate assembly 200 through the adapter pieces 430; the cover plate assembly 200 also includes a lower insulating member 230 disposed between the cover plate 210 and the adapter pieces 430, and a positioning protrusion 231 protruding toward the adapter piece 430 is formed on the surface of the lower insulating member 230 near the adapter piece 430; the positioning protrusion 231 is located on one side of one of the adapter pieces 430 along the length direction of the cover plate 210; the positioning protrusion 231 is used to limit the longitudinal position of the corresponding adapter piece 430 when the electrode assembly 400 is electrically connected to the cover plate assembly 200.

[0051] For example, among the plurality of terminals 220, at least one positive terminal 221 and at least one negative terminal 222 are included.

[0052] 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.

[0053] 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.

[0054] For example, the lower insulating member 230 and the cover plate 210 can be connected by means of adhesive bonding or heat pressing.

[0055] 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.

[0056] 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 5 In the structure shown, the positioning protrusion 231 is located near and below the upper adapter piece 430. Besides this arrangement, the positioning protrusion 231 can also be located near and above the upper adapter piece 430; or near and above the lower adapter piece 430; or near and below the lower adapter piece 430. The positioning protrusion 231 can be positioned in one of these four locations.

[0057] As described above, when the electrode assembly 400 is electrically connected to the cover plate assembly 200, the multiple adapter pieces 430 and the bare battery cell 410 are already connected as a whole (which can be called a pre-connection structure). Since the longitudinal positions of the tabs 411 of the bare battery cell 410 are relatively fixed, the longitudinal positions of the adapter pieces 430 connected to the tabs 411 of the bare battery cell 410 are also fixed. In other words, in the same electrode assembly 400, as long as one adapter piece 430 is positioned along the length of the cover plate 210, the longitudinal positions of the other adapter pieces 430 are also positioned.

[0058] 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 adapter 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 length of the cover plate 210.

[0059] Next, adjust the longitudinal position of the electrode assembly 400. At this time, the positioning protrusion 231 on the lower insulating member 230 and each adapter piece 430 are visible. When adjusting the position of the electrode assembly 400, the adapter piece 430 corresponding to the positioning protrusion 231 needs to be brought close to or even in contact with the positioning protrusion 231 so that the positioning protrusion 231 can position the adapter piece 430 along the length direction of the cover plate 210. When the adapter piece 430 is aligned with the corresponding pole post 220 under the action of the positioning protrusion 231, the other adapter pieces 430 will automatically be aligned with their respective pole posts 220, and electrical connections will be made between each adapter piece 430 and the pole post 220.

[0060] The battery provided in this embodiment has a positioning protrusion 231 formed on the surface of the lower insulating member 230 near the adapter piece 430, protruding towards the adapter piece 430. When the electrode assembly 400 is electrically connected to the cover plate assembly 200, the positioning protrusion 231 can be used as a reference to position one of the adapter pieces 430 in the electrode assembly 400 along the length direction of the cover plate 210. After the adapter piece 430 is positioned, since the relative positions of the other adapter pieces 430 in the electrode assembly 400 and the adapter piece 430 along the length direction of the cover plate 210 are relatively fixed, the longitudinal positions of the other adapter pieces 430 are also automatically positioned. 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 length direction of the cover plate 210. 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.

[0061] Meanwhile, in actual production, the spacing between adjacent adapter pieces 430 in the electrode assembly 400 along the length of the cover plate 210 may have errors that meet process requirements. If a positioning protrusion 231 is provided for each adapter piece 430, then when positioning each adapter piece 430 through the positioning protrusion 231, the positioning protrusion 231 may forcibly correct the aforementioned positional error of the adapter piece 430. The force exerted by the positioning protrusion 231 on the adapter piece 430 may be transmitted to the tab 411, thereby causing the tab 411 to tear. In this embodiment, multiple adapter pieces 430 are positioned by only one positioning protrusion 231, which allows for positional errors between adjacent adapter pieces 430 along the length of the cover plate 210 that meet process requirements. While ensuring that the adapter piece 430 can achieve reliable electrical connection with the corresponding terminal 220, it can also prevent the tab 411 from tearing, which helps to improve the reliability and safety of the battery.

[0062] like Figure 5 In some embodiments, the cover plate 210 is provided with an injection hole 211 that extends through the thickness direction of the cover plate 210; along the length direction of the cover plate 210, the injection hole 211 is close to one of the plurality of adapter pieces 430, and the positioning protrusion 231 is located between the injection hole 211 and the adapter piece 430 that is close to the injection hole 211.

[0063] It should be noted that the lower insulating component 230 is provided with a clearance through hole corresponding to the injection hole 211. The orthogonal projection of the clearance through hole on the cover plate 210 along the thickness direction of the cover plate 210 covers the injection hole 211, and the injection hole 211 can be exposed relative to the lower insulating component 230 through the clearance through hole.

[0064] by Figure 5 Taking the structure and orientation shown as an example, the battery includes two adapter pieces 430, and an injection hole 211 is located between the two adapter pieces 430 and near the upper adapter piece 430. In this embodiment, a positioning protrusion 231 is located between the upper adapter piece 430 and the injection hole 211, and near the adapter piece 430. When the adapter piece 430 is positioned by the positioning protrusion 231, the upper adapter piece 430 can only be located above the positioning protrusion 231 due to the restriction of the positioning protrusion 231, thus ensuring that the upper adapter piece 430 will not block the injection hole 211 located below the positioning protrusion 231. At the same time, since the distance between the lower adapter piece 430 and the injection hole 211 is relatively large, the lower adapter piece 430 will not block the injection hole 211 either.

[0065] Conversely, if the positioning protrusion 231 is positioned close to the lower adapter piece 430, the longitudinal position of the lower adapter piece 430 can be precisely defined by the positioning protrusion 231. However, when there is an error in the spacing between the two adapter pieces 430, the longitudinal position of the upper adapter piece 430 may be misaligned with the preset position, which may result in the blocking of the injection hole 211.

[0066] Therefore, in this embodiment, the positioning protrusion 231 is set between the injection hole 211 and the adapter piece 430 that is close to the injection hole 211. This ensures that the adapter piece 430 will not block the injection hole 211, and that the electrolyte can be smoothly injected into the accommodating space 300 through the injection hole 211. This helps to reduce the assembly difficulty of the battery and improve the assembly efficiency.

[0067] like Figure 3 and Figure 4 In some embodiments, the adapter 430 includes a terminal connection portion 431, and an electrode connection portion 431 electrically connected to the terminal connection portion 431 along the width direction of the cover plate 210 (e.g., ...). Figure 3 The electrode connection portion 432 (in the Y direction) has at least one side of the electrode connection portion 432; the electrode 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 electrode connection portion 432 includes a second surface 4321 near the bare cell 410; the adapter piece 430 has a uniform thickness and the second surface 4321 is recessed relative to the first surface 4311 toward the cover plate 210; the electrode post 220 is welded to the third surface 4312 and the electrode tab 411 is welded to the second surface 4321.

[0068] 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.

[0069] by Figure 4 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 connection part 431 is connected to the pole tab connection part 432, the adapter piece 430 is Z-shaped; when the pole post connection part 431 is connected to the pole tab connection part 432 on both opposite sides, the adapter piece 430 is Z-shaped.

[0070] Still with Figure 4 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Figure 6 Showing Figure 5 An enlarged diagram of part B in the middle. Figure 7 A schematic diagram of the adapter piece 430 for the second type of battery structure is shown. 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.

[0077] like Figure 6 , Figure 7 and Figure 8 In the adapter piece 430 corresponding to the positioning protrusion 231, a positioning groove 435 is formed on the side wall near the positioning protrusion 231 in the portion of the pole connection 431; the positioning groove 435 is recessed toward the center of the adapter piece 430 along the length direction of the cover plate 210 and penetrates the adapter piece 430 along the thickness direction of the cover plate 210; the positioning protrusion 231 is at least partially located in the positioning groove 435.

[0078] For example, the positioning groove 435 is provided only on the side of the adapter piece 430 near the positioning protrusion 231.

[0079] For example, along the length of the cover plate 210, the size of the positioning groove 435 (i.e., the depth of the positioning groove 435) is greater than the size of the positioning protrusion 231.

[0080] For example, along the width direction of the cover plate 210, the size of the positioning groove 435 (i.e., the width of the positioning groove 435) is slightly larger than the size of the positioning protrusion 231.

[0081] It should be noted that when the adapter piece 430 is welded to the pole piece 220, the pole piece 220 is approximately located at the center of the adapter piece 430. Along the length of the cover plate 210, there is sufficient space between the side wall of the pole piece 220 near the positioning protrusion 231 and the edge of the adapter piece 430 near the positioning protrusion 231 to provide a positioning groove 435, and the provision of the positioning groove 435 will not adversely affect the welding between the adapter piece 430 and the pole piece 220.

[0082] When positioning the adapter piece 430 using the positioning protrusion 231, the positioning protrusion 231 and the positioning groove 435 can be aligned with each other. When the positioning protrusion 231 enters the positioning groove 435, it means that the relative position between the adapter piece 430 and the pole post 220 has roughly met the process requirements. The positioning groove 435 can more conveniently and efficiently complete the positioning of the adapter piece 430 and the positioning protrusion 231.

[0083] At the same time, such as Figure 8 When the positioning protrusion 231 is located in the positioning groove 435, the two groove walls 4352 of the positioning groove 435 along the width direction of the cover plate 210 can cooperate with the positioning protrusion 231 to position the adapter piece 430 along the width direction of the cover plate 210, which can further improve the alignment effect between the adapter piece 430 and the pole post 220.

[0084] In addition, the positioning groove 435 extends through the adapter piece 430 along the thickness direction of the cover plate 210, which can prevent the adapter piece 430 and the positioning protrusion 231 from interfering with each other in the thickness direction of the cover plate 210. This ensures that the third surface 4312 and the end face of the pole post 220 are tightly fitted, preventing the adapter piece 430 and the pole post 220 from having poor soldering problems, and ensuring that the adapter piece 430 and the pole post 220 can form a reliable electrical connection.

[0085] Figure 9 Showing Figure 8 A partial cross-sectional schematic diagram of a structure with a CC section.

[0086] like Figure 8 and Figure 9 In some embodiments, the positioning groove 435 includes a groove bottom 4351 near the center of the adapter piece 430, and the positioning protrusion 231 includes a contact side 2311 that can contact the groove bottom 4351, and the contact side 2311 is arranged parallel to the groove bottom 4351.

[0087] For example, the bottom of the groove 4351 is perpendicular to a straight line extending along the length of the cover plate 210.

[0088] For example, the bottom of the groove 4351 may be perpendicular to the bottom surface of the lower insulating member 230, or may be inclined relative to the bottom surface of the lower insulating member 230.

[0089] If the positioning protrusion 231 needs to make the groove bottom 4351 contact the contact side 2311 when positioning the adapter piece 430, then the parallel arrangement of the contact side 2311 and the groove bottom 4351 can make the contact area between the two larger, thereby making the contact between the two more stable and preventing the adapter piece 430 from rotating horizontally around the positioning protrusion 231. This helps to achieve more accurate positioning of the adapter piece 430 through the positioning protrusion 231.

[0090] like Figure 4 , Figure 8 and Figure 9 In some embodiments, the positioning protrusion 231 includes a protruding end face 2312 near the bare cell 410, and a guide ramp is formed between the protruding end face 2312 and the contact side face 2311.

[0091] 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 bottom 4351 of the groove of 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 bottom 4351 of the groove with the contact side 2311.

[0092] 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, it can reduce the difficulty of aligning the groove bottom 4351 with the inclined surface. When the edge of the groove bottom 4351 contacts the inclined surface, it can slide down along the inclined surface. Since the contact side 2311 is connected to the bottom of the inclined surface, the groove bottom 4351 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.

[0093] Figure 10 Showing Figure 8 Partial cross-sectional schematic diagrams of two structures in the CC section.

[0094] like Figure 8 and Figure 10 In some embodiments, a guiding arc surface is formed between the protruding end face 2312 and the contact side face 2311.

[0095] 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.

[0096] like Figure 4 and Figure 6 In some embodiments, the tab 411 and the tab connection portion 432 are welded to form a tab weld mark 420. Along the width direction of the cover plate 210, the minimum distance between the positioning protrusion 231 and the tab weld mark 420 is L1, where L1 > 5 mm.

[0097] For example, L1 can be 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm or 8mm.

[0098] Combination Figure 4 The positioning protrusion 231 protrudes from the first surface 4311 toward the bare cell 410. As can be seen from the above, the tab 411 is welded to the second surface 4321 of the tab connection part 432, and the first surface 4311 protrudes from the second surface 4321 toward the bare cell 410. There is a large height difference between the protruding end face 2312 of the positioning protrusion 231 and the second surface 4321.

[0099] Understandably, the area of ​​tab 411 closest to the 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 the tab solder mark 420. If the positioning protrusion 231 is too close to the tab solder mark 420, then the positioning protrusion 231 will contact the area of ​​tab 411 closest to the tab solder mark 420 and exert a force on that area of ​​tab 411 to drive it away from the second surface 4321. Affected by this force, on the one hand, it may be difficult for the end face of the adapter piece 430 and the pole piece 220 to fit tightly, resulting in a poor solder joint between the adapter piece 430 and the pole piece 220. On the other hand, it may also cause the aforementioned area of ​​tab 411 to tear under the combined action of the tab solder mark 420 and the positioning protrusion 231.

[0100] To avoid the aforementioned problems, this embodiment designs L1 to be greater than 5mm. This allows the positioning protrusion 231 to contact the area of ​​the tab 411 that is farther 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, the area can release the force through bending deformation. This ensures a tight fit between the adapter piece 430 and the end face of the terminal post 220, guaranteeing a reliable electrical connection between the terminal post 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.

[0101] like Figure 4 In some embodiments, the tabs 411 connected to the same tab connection portion 432 include n sheet-like structures stacked along the thickness direction of the cover plate 210, where n is 30 to 90.

[0102] For example, n can be 30, 36, 40, 48, 50, 54, 60, 66, 70, 72, 80, 88 or 90.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] like Figure 4 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 H1, the thickness of the tab 411 connected to the same tab connection portion 432 is H2, and the ratio of H1 to H2 is 0.5 to 0.9.

[0107] For example, the ratio of H2 to H3 can be 0.5, 0.6, 0.7, 0.8 or 0.9.

[0108] If the ratio of H1 to H2 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 H1 to H2 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 H1 to H2 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, if the ratio of H1 to H2 is too small, it 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 cause 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.

[0109] To avoid the aforementioned problems, this embodiment designs the ratio of H1 to H2 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.

[0110] like Figure 3 , Figure 4 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.

[0111] 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.

[0112] 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 below the lower insulating member 230, so that a larger bare cell 410 can be installed in the space 300, which helps to improve the space utilization of the space 300 and the energy density of the battery.

[0113] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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 in that, 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 has a positioning protrusion protruding toward the adapter piece. The positioning protrusion is located on one side of one of the adapter pieces along the length direction of the cover plate. The positioning protrusion is used to limit the position of the corresponding adapter piece in the length direction of the cover plate when the electrode assembly is electrically connected to the cover plate assembly.

2. The battery according to claim 1, characterized in that, The cover plate is provided with an injection hole that extends through the thickness direction of the cover plate; along the length direction of the cover plate, the injection hole is close to one of the plurality of adapter pieces, and the positioning protrusion is located between the injection hole and the adapter piece that is close to the injection hole.

3. The battery according to claim 1, characterized in that, 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.

4. The battery according to claim 3, characterized in that, 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.

5. The battery according to claim 3, characterized in that, In the adapter piece corresponding to the positioning protrusion, a positioning groove is formed on the sidewall near the positioning protrusion at the pole connection portion; the positioning groove is recessed toward the center of the adapter piece along the length direction of the cover plate and extends through the adapter piece along the thickness direction of the cover plate. The positioning protrusion is at least partially located within the positioning groove.

6. The battery according to claim 5, characterized in that, The positioning groove includes a groove bottom near the center of the adapter piece, and the positioning protrusion includes a contact side that can contact the groove bottom, and the contact side is arranged parallel to the groove bottom.

7. The battery according to claim 6, characterized in that, The positioning protrusion 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.

8. The battery according to claim 3, characterized in that, The electrode lug is welded to the electrode lug connection portion to form an electrode lug weld mark. Along the width direction of the cover plate, the minimum distance between the positioning protrusion and the electrode lug weld mark is L1, where L1 > 5mm; and / or, The electrode connected to the same electrode connection portion includes n sheet-like structures stacked along the thickness direction of the cover plate, where n is 30 to 90.

9. The battery according to claim 3, characterized in that, Along the thickness direction of the cover plate, the distance between the second surface and the first surface is H1, the thickness of the electrode connected to the same electrode connection part is H2, and the ratio of H1 to H2 is 0.5 to 0.

9.

10. The battery according to claim 1, characterized in that, 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.

Images