battery

Abstract

The utility model relates to a kind of batteries, including electric core, the electric core includes electric core body and tab bundle, the tab bundle is led out from at least one side of the electric core body;The tab bundle includes by at least two pieces of tab superposition formation, and the tab in the tab bundle, along tab stacking direction is divided into first part and second part, the tab height of first part is lower than the tab height of second part;The tab is covered with tab rubber close to one end of the electric core body, the coverage area of the tab rubber is S1, unit is mm 2 , the area of the tab in the first part is S2, unit is mm 2 , and above-mentioned parameter satisfies: 0.03≤S1 / S2≤0.25.In the utility model, the welding operation between tab and adapter piece or external terminal can be smoothly, and the performance and safety of battery are ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery. Background Technology

[0002] Lithium-ion batteries are widely used in consumer electronics, new energy vehicles, and energy storage. Their performance and safety are highly dependent on the precise design and manufacturing process of their internal cell structure. During cell manufacturing, electrodes are typically made by coating electrochemically active materials onto a metal current collector (aluminum foil for the positive electrode and copper foil for the negative electrode). In the electrode fabrication stage, to meet the requirements for subsequent tab lead-out and fixation, tab adhesive (also known as tab fixing tape) is often applied to the current collector side of the electrode to enhance the structural stability of the tabs and prevent displacement or breakage.

[0003] Subsequently, the electrode sheets undergo rolling, slitting, and cutting processes to form electrode sheets with tab structures, which are then stacked through winding or lamination processes to form a complete battery cell. In this multi-layer electrode structure, the tabs serve as the main channels for current to be drawn out from the inside of the battery cell, and their arrangement and bonding quality directly affect the welding efficiency and structural reliability of the battery cell.

[0004] However, in the existing technology, since the tabs are often of uniform length in the design, when the multiple layers of electrode sheets are stacked and gathered to the top of the cell, phenomena such as mis-layering, crossing or uneven arrangement of the tabs will occur, which will affect the accuracy and consistency of the welding process, and even cause problems such as poor tab soldering, thermal stress concentration and poor connection. Utility Model Content

[0005] The purpose of this invention is to provide a battery that allows for smooth welding operations between the tabs and the adapter or external terminals, while ensuring the battery's performance and safety.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] A battery includes a cell, the cell comprising a cell body and a tab bundle, the tab bundle extending from at least one side of the cell body; the tab bundle comprises tabs formed by stacking at least two tabs, and the tabs in the tab bundle are divided into a first portion and a second portion along the tab stacking direction, the tab height of the first portion being lower than the tab height of the second portion; one end of each tab near the cell body is covered with tab adhesive, the coverage area of ​​the tab adhesive being S1, in mm. 2 The area of ​​the tab in the first part is S2, in mm. 2 And the above parameters satisfy:

[0008] 0.03≤S1 / S2≤0.25.

[0009] Compared with the prior art, the battery of this utility model embodiment has the following advantages:

[0010] In this invention, the existing technology proposes to adjust the height of each layer of tabs to optimize the stacking neatness of the tabs after multiple layers of tabs are gathered, reduce misalignment, and improve overall welding consistency. Since the plane of the tabs in the first part has a smaller weldable area compared to the tabs in the second part, and the tab adhesive covering the base of the tabs near the cell body also occupies the weldable area, to ensure subsequent welding work, it is necessary to satisfy 0.3≤S1 / S2≤0.25 to avoid the tab adhesive occupying too much of the weldable area of ​​the tabs. This ensures that the weldable area of ​​the shortest tab can meet the subsequent welding work, guaranteeing that multiple tabs can be stably welded to the adapter or external terminal after being gathered. Attached Figure Description

[0011] Figure 1 This is a perspective view of the battery according to an embodiment of the present utility model;

[0012] Figure 2 This is a schematic diagram of a battery according to an embodiment of the present invention;

[0013] Figure 3 This is a schematic diagram of the battery cell body and the electrode tabs according to an embodiment of the present utility model;

[0014] Figure 4 This is a schematic diagram of the electrode sheet and electrode tab in an embodiment of this utility model;

[0015] Figure 5 This is a schematic diagram showing the height of the first and second parts of the electrode tab in an embodiment of this utility model;

[0016] In the diagram, 1 is the battery cell body; 11 is the electrode sheet; 2 is the electrode bundle; 20 is the electrode tab; 21 is the first arc-shaped part; 22 is the second arc-shaped part; 23 is the first part; 24 is the second part; 3 is the electrode tab adhesive; 4 is the housing; 5 is the cover; 6 is the electrode post; and 7 is the adapter plate. Detailed Implementation

[0017] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0018] In the description of this utility model, it should be understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, parts, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, parts, components, and / or groups thereof. It should be understood that when we say a part is "connected" to another part, it can be directly connected to the other part, or there may be intermediate parts. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0019] In existing technologies, due to the design of the strip structure and the tab cutting mechanism, the tabs in a battery cell are often of uniform length during the processing stage. When the tabs are gathered to one side to form a tab bundle, the different distances from the base of each tab to the gathering direction cause misalignment of the tops of the gathered tabs, resulting in tab misalignment. Furthermore, due to processing precision and assembly tolerances, the tabs may cross or be unevenly arranged in the tab lead-out direction and tab width direction after gathering. This affects the precision and consistency of the welding process, and may even lead to problems such as incomplete tab soldering, thermal stress concentration, and poor connection. To address this, this invention optimizes the tab stacking neatness by adjusting the length of each layer of tabs, reducing misalignment and improving overall welding consistency.

[0020] like Figures 1 to 4 As shown, this utility model relates to a battery, including a battery cell. The battery cell includes a battery cell body 1 and a tab bundle 2. The tab bundle 2 extends from at least one side of the battery cell body 1. The tab bundle 2 is formed by stacking at least two tabs 20, and the tabs 20 in the tab bundle 2 are divided into a first part and a second part along the stacking direction of the tabs 20. The tab height of the first part is lower than the tab height of the second part.

[0021] The above solution also raises new problems. The step of applying tab adhesive 3 to the base of electrode 11 occurs before the tab 20 is cut. Therefore, if electrode 11 of different heights is to be designed, when the tab 20 is cut after the tab adhesive 3 is applied, the area occupied by tab adhesive 3 on the first part of the tab 20 with a shorter height may be too large. The limited metal lead-out area will be occupied by tab adhesive 3 in a large proportion, thereby compressing the effective solderable area. This is not conducive to the soldering operation between the tab 20 and the adapter piece 7 or external terminals, and may even lead to poor soldering, increased contact resistance, and in severe cases, affect the performance and safety of the battery cell.

[0022] Therefore, it is necessary to control the area of ​​the tab adhesive 3 on the first part of the tab 20. The end of the tab 20 closest to the cell body 1 is covered with tab adhesive 3, and the coverage area of ​​the tab adhesive 3 on the first part of the tab is S1, in mm. 2 The area of ​​the plane of the first part of the electrode is S2, in mm. 2 And the above parameters satisfy:

[0023] 0.03≤S1 / S2≤0.25.

[0024] The values ​​of S1 / S2 can also be 0.03, 0.05, 0.07, 0.1, 0.12, 0.15, 0.17, 0.2, 0.22, 0.23, 0.24 or 0.25, or any value between 0.03 and 0.25.

[0025] The coverage area S1 of the tab adhesive 3 is 100mm. 2 ≤S1≤800mm 2 The value of S1 can also be 100mm. 2 150mm 2 200mm 2 300mm 2 400mm 2 600mm 2 700mm 2 or 800mm 2 It can also be 100mm 2 Up to 800mm 2 Any value in the range.

[0026] The area S2 of the tab 20 mentioned in the first part is 3mm. 2 ≤S2≤200mm 2 S2 can also be 3mm 2 10mm 2 35mm 2 60mm 2 80mm 2 100mm 2 130mm 2 160mm 2 180mm 2 or 200mm 2 It can also be 3mm 2 Up to 200mm 2 Any value in the range.

[0027] In this invention, the existing solution proposes to optimize the stacking neatness of the tabs 20 after multiple layers of tabs 20 are gathered by adjusting the height of each layer of tabs 20, reducing misalignment and improving overall welding consistency. Since the plane of the tabs 20 in the first part has a smaller weldable area compared to the tabs 20 in the second part, and the tab adhesive 3 covering the base of the tabs 20 near the cell body 1 also occupies the weldable area of ​​the tabs 20, to ensure subsequent welding work of the tabs 20, it is necessary to satisfy 0.3≤S1 / S2≤0.25 to avoid the tab adhesive 3 occupying too much of the weldable area of ​​the tabs 20, so that the weldable area of ​​the tabs 20 in the first part can meet the subsequent welding work, ensuring that multiple tabs 20 can be stably welded to the adapter piece 7 or external terminals after being gathered.

[0028] In some embodiments, the tab 20 includes a positive tab and a negative tab, which can both be led out from the same side of the cell body 1, or the positive tab and the negative tab can be led out from opposite sides of the cell body 1.

[0029] In some embodiments, the cell body 1 includes multiple layers of stacked electrode sheets 11, and a plurality of tabs 20 extend from the same side of the multiple layers of electrode sheets 11. At least one side of the tab 20 adjacent to the electrode sheet 11 is arcuately transitioned to the electrode sheet 11, forming a first arcuate portion 21.

[0030] Specifically, the tab 20 and the electrode 11 are adjacent to each other on both sides with an arc transition to the electrode 11, so that a first arc portion 21 is formed on both sides of the tab 20 near the electrode 11. The first arc portion 21 has the function of releasing stress, which can reduce the stress concentration problem at the corner between the tab 20 and the electrode 11, thereby making the tab 20 and the electrode 11 less prone to tearing, and ensuring the stability of the connection between the tab 20 and the electrode 11.

[0031] Furthermore, the radius of the first arc-shaped portion 21 is R1, in mm, and the above parameters satisfy:

[0032] 1.5mm≤R1≤10mm.

[0033] The value of R1 can also be 1.5mm, 1.7mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.2mm, 9.5mm, 9.7mm, 9.9mm or 10mm, or any value from 1.5mm to 10mm.

[0034] Since the first arc-shaped portion 21 itself has the function of releasing stress and can reduce stress concentration, a larger arc of the first arc-shaped portion 21 can release more stress. However, if the first arc-shaped portion 21 is too large, it will also cause the size of the electrode tab 20 to be too large and occupy too much space. Therefore, it can be kept at 1.5mm≤R1≤10mm to ensure that the electrode tab 20 and the electrode plate 11 are stably connected without the electrode tab 20 occupying too much space.

[0035] In some embodiments, the tab 20 has an arcuate transition between at least one side adjacent to the electrode 11 and the side of the tab 20 away from the electrode 11, forming a second arcuate portion 22.

[0036] Specifically, the two sides of the tab 20 adjacent to the electrode plate 11 are arc-shaped transitions with the side of the tab 20 away from the electrode plate 11, so that the second arc-shaped portion 22 is formed on both sides of the end of the tab 20 away from the electrode plate 11. This helps to prevent the two corners of the end of the tab 20 away from the electrode plate 11 from turning over, and can ensure that multiple tabs 20 can be stacked together neatly to ensure the smooth welding process.

[0037] Furthermore, the radius of the second arcuate portion 22 is R2, in mm, and the above parameters satisfy:

[0038] 2mm≤R2≤15mm.

[0039] The value of R2 can also be 2mm, 2.2mm, 2.5mm, 2.7mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.2mm, 14.5mm, 14.7mm, or 15mm, or any value from 2mm to 15mm.

[0040] The greater the curvature of the second arc-shaped portion 22, the less likely the corner of the electrode tab 20 away from the electrode plate 11 will be flipped. However, if the curvature of the second arc-shaped portion 22 is too large, it will also cause the electrode tab 20 to be too large and occupy too much space. To address this, we can keep 2mm≤R2≤15mm to keep the curvature of the second arc-shaped portion 22 within a reasonable range, so that multiple electrodes tabs 20 can be neatly stacked together, reducing the flipping and ensuring smooth subsequent welding, and preventing the electrodes tab 20 from occupying too much space.

[0041] In some embodiments, the minimum distance between the side of the tab 20 of the first portion away from the cell body 1 and the side of the tab adhesive 3 away from the cell body 1 is L, in mm, and the above parameters satisfy:

[0042] 10mm≤L≤35mm.

[0043] The value of L can also be 10mm, 11mm, 12mm, 15mm, 17mm, 20mm, 22mm, 25mm, 27mm, 30mm, 32mm, 33mm, 34mm or 35mm, or any value from 10mm to 35mm.

[0044] If L is too large, it means that the height of the first part of the tab 20 is too large, and the height of the second part of the tab 20 will also be too large. This will cause the tab 20 to occupy too much space inside the battery, affecting the layout. If L is too small, it will cause the weldable area on the first part of the tab 20 to be too small in the direction from the tab 20 to the electrode 11, which will affect the subsequent welding work. Therefore, it is necessary to keep 10mm≤L≤35mm to ensure that the subsequent welding work between the tab 20 and the adapter piece 7 or the external terminal is smooth, and that the tab 20 does not occupy too much space inside the cell.

[0045] In some embodiments, the cell body 1 is a wound cell, wherein 0.04≤S1 / S2≤0.25.

[0046] It should be noted that wound cells are generally made by winding continuous positive electrode plates, negative electrode plates, and separators. The separator is located between adjacent positive and negative electrode plates.

[0047] In some embodiments, the cell body 1 is a laminated cell, wherein 0.03≤S1 / S2≤0.23.

[0048] It should be noted that a laminated cell is a cell made by laminating positive electrode plates, negative electrode plates, and separators. The positive and negative electrode plates are separated by a separator. The adjacent positive and / or negative electrode plates in the cell are discontinuous. The lamination process includes stacking or Z-shaped folding.

[0049] In some embodiments, the thickness of the tab adhesive 3 is T, in μm, and the above parameters satisfy:

[0050] 10μm≤T≤100μm.

[0051] The value of T can also be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 97μm or 100μm, or any value from 10μm to 100μm.

[0052] The greater the thickness of the tab adhesive 3, the more stable the connection between the tab 20 and the electrode 11, and the less likely it is to tear at the corners between the tab 20 and the electrode 11. However, the thickness of multiple tabs 20 stacked together would be too large. Therefore, it is necessary to maintain 10μm ≤ T ≤ 10μm.

[0053] In some embodiments, the tab adhesive 3 is made of PI or PET.

[0054] The tab adhesive 3 made of PI or PET has good thermal stability and aging resistance, which helps to improve service life.

[0055] In some embodiments, the battery further includes a housing 4, a cover 5, a terminal post 6, and an adapter plate 7. An opening is provided on one side of the housing 4, the cover 5 is placed over the opening, the terminal post 6 is placed on the cover 5, the adapter plate 7 is placed inside the housing 4 and welded to the terminal post 6, the battery cell is placed inside the housing 4, and a plurality of electrode bundles 2 are welded to the adapter plate 7.

[0056] like Figure 2 As shown, the adapter 7 is disposed between the cover 5 and the cell body 1, and the tab bundle 2 extends between the cover 5 and the adapter 7, and is welded to the surface of the adapter 7 near the cover 5. This structure eliminates the need for the tab bundle 2 to bend below the adapter 7, effectively reducing the space occupied in the height direction of the battery after bending, thus allowing for a larger cell to be arranged in the battery and increasing the battery's energy density. Therefore, the preferred arrangement is for the tab bundle 2 to be welded to the surface of the adapter 7 near the cover 5. Welding the tab bundle 2 to the surface of the adapter 7 away from the cover 5 is also an optional arrangement.

[0057] When the tab bundle 2 is welded to the surface of the adapter piece 7 on the side near the cover 5, the end of the tab bundle 2 away from the cell body 1 is close to the welding area between the terminal post 6 and the adapter piece 7. If the end of the tab bundle 2 is not spaced from the terminal post 6, an excessively long tab bundle 2 may insert into the welding area between the terminal post 6 and the adapter piece 7, affecting the welding effect. Therefore, the distance between the end of the tab bundle 2 and the terminal post 6 is d1, in mm, and the above parameters satisfy:

[0058] 0.5mm≤d1≤25mm.

[0059] The value of d1 can also be 0.5mm, 1mm, 3mm, 7mm, 9mm, 10mm, 12mm, 15mm, 18mm, 22mm or 25mm, or any value from 0.5mm to 25mm.

[0060] It should be noted that a battery cell is the component in a battery where electrochemical reactions occur; it is the smallest unit in a battery capable of carrying out electrochemical reactions such as charging / discharging.

[0061] A battery cell is the basic unit of a battery, typically consisting of a positive electrode, a negative electrode, and a separator. Lithium-ion cells primarily function by the movement of lithium ions between the positive and negative electrodes. In cylindrical cells, a three-layer thin-film structure is wound into a cylindrical electrode assembly, while in cuboid cells, the thin-film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0062] The housing 4 is a component used to provide a space to house the battery cell and other components and isolate them from the outside environment. The housing 4 generally includes a body with an opening at at least one end and a receiving cavity. The opening of the housing 4 can be closed by a cover 5 to seal and isolate the internal environment of the battery cell from the external environment.

[0063] The materials of the casing 4 include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and aluminum-plastic film.

[0064] The cover 5 is a component that closes the opening of the housing 4 to isolate the internal environment of the battery cell from the external environment.

[0065] The materials of the cover 5 include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and aluminum-plastic film.

[0066] Terminal 6 is used to electrically connect the battery cell located inside the housing 4 to external devices (adjacent batteries or other electrical equipment) located outside the housing 4. The battery can discharge to external devices through the output terminal of the battery cell (tab 20) and the output terminal of the external device (terminal 6). An external power source can charge the battery through terminal 6 and tab 20. Terminal 6 can be directly electrically connected to the tab 20 of the battery cell, or it can be electrically connected to the tab 20 through an adapter 7.

[0067] The tab 20 is located on one side of the positive / negative current collector and is separately / integrated with the current collector, and is electrically connected to the current collector to conduct the current on the corresponding current collector.

[0068] The tab 20 is made of a metal material with good electrical conductivity (such as copper, aluminum, copper or nickel).

[0069] The tab adhesive is applied to at least one side of the current collector near the tab, or to at least one side of the surface of the tab 20, to prevent short circuit between the tab 20 and the opposite electrode 11; it can also prevent the tab 20 from breaking when bent during battery cell assembly.

[0070] The tab adhesive 3 mainly includes insulating materials such as PVDF (polyvinylidene fluoride), boehmite, polypropylene, and polyethylene.

[0071] The pole piece 6 is made of metal materials including but not limited to copper, aluminum, aluminum alloy, and copper-aluminum alloy.

[0072] One end of the adapter 7 is used to electrically connect to the output terminal (tab 20) of the battery cell, and the other end is used to electrically connect to the output terminal (terminal 6) of the battery, so that the tab 20 and the terminal 6 form a current conduction.

[0073] Positive electrode adapter: Used to electrically connect the positive output terminal of the cell to the positive output terminal of the battery. Multiple positive electrode tabs stacked together are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive terminal of the terminal 6.

[0074] The negative electrode adapter is used to electrically connect the negative output terminal of the cell to the negative output terminal of the battery. Multiple negative electrode tabs stacked together are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode of the terminal post 6.

[0075] The adapter piece 7 can be made of aluminum, copper, or an alloy (such as steel), or other conductive materials. The specific material of the adapter piece 7 is selected based on the materials of the battery terminals 6 and 20. Generally, the material of the adapter piece 7 must be the same as that of the battery terminals 20 and 6 to ensure welding quality.

[0076] The positive electrode is one of the core components in a battery that carries the positive electrode active material. During charging, metal ions (e.g., lithium ions) are released from the crystal lattice of the positive electrode active material (oxidation reaction), migrate through the electrolyte, and intercalate into the negative electrode. During discharging, metal ions (e.g., lithium ions in a lithium battery) are released from the negative electrode and intercalate into the crystal lattice of the positive electrode active material (reduction reaction), thus realizing the storage and release of lithium ions.

[0077] A positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is coated on at least one surface of the positive current collector and includes: a positive active material, a conductive agent, and a binder. The positive active material includes, but is not limited to, at least one of the following: lithium phosphates, lithium transition metal oxides and their respective modified compounds, or other conventional materials that can be used as positive electrode active materials in batteries. These positive active materials can be used alone or in combination. Lithium phosphates include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (e.g., LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0078] The positive electrode conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P, etc.), carbon nanotubes, graphene and carbon nanofibers.

[0079] The positive electrode binder includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0080] The function of the negative electrode: During battery charging, active ions (such as Li) from the positive electrode are embedded in the negative electrode, while electrons from the positive electrode are transferred to the negative electrode through the external circuit to maintain charge balance; During discharge, the active ions (such as Li) previously embedded in the negative electrode can be released, while electrons from the negative electrode are transferred to the negative electrode through the external circuit to maintain charge balance; thus realizing the storage and release of energy.

[0081] The negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector. The negative electrode current collector is a conductive metal foil, which can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The negative electrode active layer includes a negative electrode active material, a conductive agent, and a binder.

[0082] The negative electrode active material can be carbon-based materials such as graphite, porous carbon, hard carbon, soft carbon, and mesophase carbon microspheres, or silicon-based materials such as elemental silicon, silicon oxides, silicon-carbon composites, and silicon-nitrogen composites. The conductive agent can be conductive carbon black, carbon nanotubes, etc., and the binder can be styrene-butadiene rubber, polyacrylic acid, etc.

[0083] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery, characterized by, The battery includes a battery cell, which comprises a cell body and a tab bundle. The tab bundle extends from at least one side of the cell body. The tab bundle is formed by stacking at least two tabs, and the tabs in the tab bundle are divided into a first part and a second part along the tab stacking direction. The height of the tabs in the first part is lower than the height of the tabs in the second part. The end of each tab near the cell body is covered with tab adhesive, and the coverage area of ​​the tab adhesive is S1, in mm. 2 The area of ​​the tab in the first part is S2, in mm. 2 And the above parameters satisfy: 0.03≤S1 / S2≤0.

25.

2. The battery of claim 1, wherein, The cell body includes a plurality of layers of laminated electrode plates, and a plurality of the tabs extend from the same side of the plurality of layers of the electrode plates, and the at least one side of the tab adjacent to the electrode plate and the electrode plate are arc-shaped transitioned and form a first arc-shaped part.

3. The battery of claim 2, wherein, The radius of the first arc-shaped part is R1, unit: mm, and the above parameters satisfy: 1.5mm≤R1≤10mm.

4. The battery of claim 2, wherein, The at least one side of the tab adjacent to the electrode plate and the side of the tab away from the electrode plate are arc-shaped transitioned and form a second arc-shaped part.

5. The battery of claim 4, wherein, The radius of the second arc-shaped part is R2, unit: mm, and the above parameters satisfy: 2mm≤R2≤15mm.

6. The battery of claim 1, wherein, The distance between the side of the tab of the first part away from the cell body and the side of the tab adhesive away from the cell body is L, unit: mm, and the above parameters satisfy: 10mm≤L≤35mm.

7. The battery of claim 1, wherein, The cell body is a winding type cell, wherein 0.04≤S1 / S2≤0.

25.

8. The battery of claim 1, wherein, The cell body is a laminated cell, wherein 0.03≤S1 / S2≤0.

23.

9. The battery of claim 1, wherein, The thickness of the tab adhesive is T, unit: μm, and the above parameters satisfy: 10μm≤T≤100μm.

10. The battery of claim 1, wherein, The tab adhesive is made of PI or PET.

11. The battery of claim 1, wherein, Further comprising a shell, a cover, a pole and a adapter sheet, one side of the shell is provided with an opening, the cover is covered on the opening, the pole is arranged on the cover, the adapter sheet is arranged in the shell and welded with the pole, the cell is arranged in the shell, and the tab bundle is welded on the adapter sheet.

12. The battery of claim 11, wherein, The adapter sheet is arranged between the cover and the cell body, the tab bundle extends between the cover and the adapter sheet, and is welded on the surface of the side of the adapter sheet close to the cover.

13. The battery of claim 12, wherein, The distance between the end of the tab bundle away from the cell body and the pole is d1, unit: mm, and the above parameters satisfy: 0.5mm≤d1≤25mm.

14. The battery of any one of claims 1-13, wherein, The covering area S1 of the tab adhesive ranges from 100 mm 2 ≤ S1 ≤ 800 mm 2 , and / or the area S2 of the tab in the first portion ranges from 3 mm 2 ≤ S2 ≤ 200 mm 2 .

Images