Cells and Batteries

Abstract

The present application provides a battery cell and a battery, which relates to the field of battery technology. The battery cell includes: a first pole piece, a diaphragm, and a second pole piece, which are stacked, wherein the first pole piece and the second pole piece have opposite polarities, the first pole piece includes a first current collector, the first pole piece includes a plurality of soft pole ears protruding from the first current collector, and the plurality of soft pole ears are stacked; a hard pole ear, which is stacked and electrically connected to the outermost one of the plurality of soft pole ears; a conductive adhesive, including a first adhesive layer, at least part of the space between two adjacent soft pole ears is filled with the first adhesive layer, and the space between the adjacent hard pole ears and the soft pole ears is filled with the first adhesive layer. According to the battery cell of the present application, the surface of the connection part between the soft pole ear and the hard pole ear is relatively flat, and the adhesive tape affixed to the protruding part to prevent the protrusion from piercing the external aluminum-plastic film is omitted, which can improve the space utilization rate of the battery head and prevent the protrusion from causing an internal short circuit in the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell and a battery. Background Art

[0002] With the development of social economy and science and technology, batteries are being used more and more widely in various fields, and the performance requirements for batteries are also getting higher and higher. As an important component for batteries to store and supply energy, the soft tabs of the battery cell are connected to the battery electrodes through the hard tabs to achieve current exchange with the outside.

[0003] At present, the most commonly used method for connecting soft tabs and hard tabs is welding, such as ultrasonic welding, laser welding, resistance welding, etc.

[0004] However, the above welding methods may result in bulges on the weld mark due to the solidification of the molten pool after welding. The bulge will affect the utilization rate of the battery head space and there is a risk of piercing the adhesive tape and causing an internal short circuit in the battery. Utility Model Content

[0005] Considering that welding the soft pole ear and the hard pole ear may cause bulges at the weld mark due to the solidification of the molten pool after welding, the bulge will affect the utilization rate of the battery head space and there is a risk of piercing the adhesive tape and causing internal short circuit of the battery. The present application provides a battery cell and a battery that can eliminate the bulge at the connection between the soft pole ear and the hard pole ear, improve the utilization rate of the battery head space, and improve the battery safety.

[0006] The present application provides a battery cell, comprising: a first pole piece, a diaphragm, and a second pole piece, wherein the first pole piece, the diaphragm, and the second pole piece are stacked, wherein the polarities of the first pole piece and the second pole piece are opposite, the first pole piece comprises a first current collector, the first pole piece comprises a plurality of soft pole ears protruding from the first current collector, and the plurality of soft pole ears are stacked; a hard pole ear, wherein the hard pole ear is stacked and electrically connected to the outermost one of the plurality of soft pole ears; and a conductive adhesive, comprising a first adhesive layer, wherein at least a portion of the space between two adjacent soft pole ears is filled with the first adhesive layer, and the space between adjacent hard pole ears and the soft pole ears is filled with the first adhesive layer.

[0007] According to the battery cell of the present application, the soft pole ear and the hard pole ear and the multiple soft pole ears are connected by conductive glue, so that the current can be transmitted between the multiple soft pole ears and between the soft pole ear and the hard pole ear through the conductive glue. In this way, the surface of the soft pole ear and the hard pole ear is relatively flat as a whole, avoiding the protrusions and burrs that may be generated at the welding mark when the welding scheme is adopted in the related art, and also eliminating the adhesive tape attached to the protruding part to prevent the protrusion from piercing the external aluminum-plastic film. The saved protrusion thickness and adhesive tape thickness can improve the space utilization rate of the battery head to improve the battery energy density, and can avoid the protrusion piercing the adhesive tape and other structures in the related art, thereby avoiding internal short circuit of the battery and improving safety.

[0008] In addition, compared with the solution of welding the soft pole ear to the hard pole ear in the related art, it can also avoid the welding slag and metal particles generated by welding from contacting the battery cell, causing serious self-discharge of the finished battery and poor electrical performance. It can also avoid the problem of cold welding caused by aging, wear, insufficient power of welding equipment, etc., to avoid chip falling, affecting the battery's charge and discharge path, and ensure the battery's charge and discharge performance.

[0009] In some embodiments, the hard pole ear and the soft pole ear have an overlapping area, the projection of the first adhesive layer in the reference plane is within the projection of the overlapping area in the reference plane, and the reference plane is parallel to the straight surface on either side of the battery cell along the thickness direction.

[0010] In some embodiments, the area of ​​the overlap region is 0.3 mm 2 -500mm 2 ; and / or, the ratio of the area of ​​the first adhesive layer to the area of ​​the overlapping region is in the range of 0.5-0.9; and / or, the thickness of the first adhesive layer is in the range of 1μm-10μm; and / or, the ratio of the total thickness of the first adhesive layer to the sum of the thicknesses of the multiple soft pole ears and the multiple first adhesive layers is in the range of 0.01-0.5.

[0011] In some embodiments, the conductive adhesive further includes a second adhesive layer, and at least part of the plurality of soft tabs is provided with a receiving structure, and the receiving structure is filled with the second adhesive layer.

[0012] In some embodiments, the accommodation structure is formed as a connecting hole that penetrates the soft electrode tab along the thickness direction of the soft electrode tab.

[0013] In some embodiments, both ends of the second adhesive layer are provided with the first adhesive layer, and both ends of the second adhesive layer are respectively connected to the first adhesive layer.

[0014] In some embodiments, the first adhesive layer is disposed at the first end of the second adhesive layer, the first end of the second adhesive layer is connected to the first adhesive layer, and the second end of the second adhesive layer is connected to the soft electrode tab.

[0015] In some embodiments, the thickness of the second adhesive layer is in a range of 5 μm-20 μm; and / or the ratio of the total volume of all the second adhesive layers to the total volume of all the conductive adhesives is in a range of 0.5-0.9.

[0016] In some embodiments, the communication holes on any two adjacent soft electrode ears are staggered or aligned with each other along the first direction and / or the second direction.

[0017] In some embodiments, the accommodating structure is a groove formed on the surface of the soft electrode ear, and the conductive glue is filled in the groove.

[0018] In some embodiments, the ratio of the volume of the second adhesive layer in all the grooves to the volume of all the conductive adhesives is 0.1-0.5.

[0019] The present application also provides a battery, comprising: a shell; and the battery cell described in the first aspect of the present application, wherein the battery cell is disposed in the shell.

[0020] The battery of the present application, by providing the above-mentioned battery cell, does not produce a bulge at the connection part after the soft pole ear and the hard pole ear are connected, and the adhesive tape provided on the back of the soft pole ear in the related art to prevent the bulge after the soft pole ear from piercing the external aluminum-plastic film is omitted, which is conducive to saving the head space of the battery and improving the space utilization rate inside the battery, thereby improving the battery energy density. It can also avoid the generation of welding slag and metal particles to prevent the welding slag and metal particles from contacting the battery cell and causing serious self-discharge of the finished battery and poor electrical performance. It can also avoid the phenomenon of cold welding generated in the welding scheme, avoid chip falling, and affect the charge and discharge path of the battery, thereby ensuring the charge and discharge performance and safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 is a schematic diagram of the structure of the battery cell of this embodiment;

[0023] Figure 2 For the battery cells in some embodiments of the present application Figure 1 Sectional view of the AA section;

[0024] Figure 2a for Figure 2 A magnified image of the area where the conductive adhesive is located;

[0025] Figure 3 For other embodiments of the present application, the battery cell Figure 1 Sectional view of the AA section;

[0026] Figure 3a for Figure 3 A magnified image of the area where the conductive adhesive is located;

[0027] Figure 4 For some other embodiments of the present application, the battery cell Figure 1 Cross-sectional view of the BB section.

[0028] Description of reference numerals:

[0029] 100-battery cell;

[0030] 1-Battery cell body;

[0031] 11-pole ear; 111-soft pole ear; 112-communication hole; 113-groove;

[0032] 2-hard pole ear;

[0033] 3-conductive adhesive; 31-first adhesive layer; 32-second adhesive layer. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0035] With the development of social economy and science and technology, batteries are used more and more widely in various fields, and the performance requirements of batteries are also getting higher and higher. As an important component for battery storage and energy supply, the battery cell has multiple soft pole ears connected to the hard pole ears to realize the current exchange with the outside through the hard pole ears. At present, the most commonly used connection method between the soft pole ears and the hard pole ears is welding, such as ultrasonic welding, laser welding, resistance welding, etc. However, the above welding methods may cause bulges on the weld mark after welding due to the solidification of the molten pool. This bulge will affect the utilization rate of the battery head space, and there is a risk of piercing the adhesive tape and causing an internal short circuit in the battery.

[0036] It should be noted that the soft pole ear is usually a plurality of protrusions formed on one or both sides of the width direction of the current collector after the foil is die-cut in the previous process of the current collector, that is, the soft pole ear is integrated with the current collector, and its material is the same as the current collector, and the thickness is similar or the same; of course, the soft pole ear can also be separately provided with the current collector, that is, the soft pole ear is a foil with a material similar or the same thickness as the current collector, which is bonded or welded on one or both sides of the width direction of the current collector, and the material of the soft pole ear includes one or more of copper, aluminum and / or nickel. In addition, the hard pole ear is usually made of a metal sheet with a thickness exceeding that of the soft pole ear, and its material usually includes one or more of aluminum and / or nickel. The hard pole ear has higher strength and current-carrying capacity than the soft pole ear.

[0037] In view of this, the present application provides a battery cell and a battery, wherein the soft pole ear and the hard pole ear and the multiple soft pole ears are connected by conductive adhesive, so that the multiple soft pole ears constituting the soft pole ear and the soft pole ear and the hard pole ear can transmit current through the conductive adhesive. In this way, the surface of the soft pole ear and the hard pole ear is relatively flat as a whole, avoiding the protrusions and burrs that may be generated at the welding mark when the welding scheme is adopted in the related art, and also eliminating the adhesive tape attached to the protruding part to avoid the protrusion piercing the external aluminum-plastic film. The saved protrusion thickness and adhesive tape thickness can improve the space utilization rate of the battery head to improve the battery energy density, and can avoid the protrusion piercing the adhesive tape and other structures in the related art, thereby avoiding internal short circuit of the battery and improving safety.

[0038] In the embodiments of the present application, the battery may be a primary battery or a secondary battery. A primary battery refers to a battery that cannot be recharged and reused after the battery is discharged, and a secondary battery refers to a battery that can be recharged to activate the active material and continue to be used after the battery is discharged. The battery may be any one of a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, and a nickel hydrogen battery. Of course, the embodiments of the present application are not limited to this.

[0039] The battery cell 100 of the embodiment of the present application may include: a first pole piece, a second pole piece, a diaphragm and a hard pole ear 2. The first pole piece, the second pole piece and the diaphragm may constitute a battery cell body 1, wherein the diaphragm is located between the first pole piece and the second pole piece, and the polarities of the first pole piece and the second pole piece are opposite, for example, the first pole piece may be a positive pole piece, and the second pole piece may be a negative pole piece; or, the first pole piece is a negative pole piece, and the second pole piece is a positive pole piece. The first pole piece includes a first current collector and a first active material coated on the surface of the first current collector, and the second pole piece includes a second current collector and a second active material coated on the surface of the second current collector. When the first pole piece, the diaphragm and the second pole piece are all multiple and the multiple first pole pieces and the second pole pieces are alternately stacked to form the battery cell 100, the battery cell 100 is a laminated battery cell 100; when the first pole piece, the diaphragm and the second pole piece are wound to form the battery cell 100 after being stacked, the battery cell 100 is a wound battery cell 100.

[0040] The following description is made by taking the first electrode sheet as the positive electrode sheet and the second electrode sheet as the negative electrode sheet as an example.

[0041] refer to Figure 1 The first pole piece includes a plurality of soft pole ears 111 protruding from the first current collector. The plurality of soft pole ears 111 are stacked and connected. The plurality of soft pole ears 111 can together constitute the pole ears 11 of the battery cell to transmit current to the outside as a whole.

[0042] The hard tab 2 can realize current transmission between the battery cell 100 and an external electrical device. Part of the structure of the hard tab 2 is stacked and connected with the outermost soft tab 111.

[0043] The conductive adhesive 3 includes a first adhesive layer 31, and the first adhesive layer 31 is filled between at least part of two adjacent soft pole ears 111. For example, the first adhesive layer 31 is filled between any two adjacent soft pole ears 11, or the first adhesive layer 31 is filled between part of the soft pole ears 11. The first adhesive layer 31 is filled between the adjacent hard pole ears 2 and the soft pole ears 111. Since the soft pole ears 111 and the hard pole ears 2, as well as the multiple soft pole ears 111, can be electrically connected by the viscosity of the conductive adhesive 3, the soft pole ears 111 will not be damaged, thereby improving the reliability of the connection of the soft pole ears 111 during the battery cycle and improving the safety performance.

[0044] For example Figure 2aAs shown, a first glue coating gap is formed between the hard pole ear 2 and the soft pole ear 111, and the first glue coating gap here refers to the gap between the hard pole ear 2 and the uppermost soft pole ear 111 among the multiple soft pole ears 111. A second glue coating gap is formed between any two of the multiple soft pole ears 111, one of the multiple first glue layers 31 is arranged in the first glue coating gap, and the rest of the multiple first glue layers 31 are respectively arranged in the second glue coating gap. In this way, the conductive glue 3 can bond the soft pole ear 111 to the hard pole ear 2, and bond the multiple soft pole ears 111, and the connection method is relatively simple and easy to implement.

[0045] The conductive adhesive 3 is a conductive material with viscosity. Specifically, the conductive adhesive 3 may include a conductive agent, an adhesive, a welding enhancer and a dispersant.

[0046] The conductive agent is used to provide electronic conduction to realize the conductive effect of the conductive layer. As an example, the conductive agent can be SUPER P Li (SP), acetylene black (AB), EnsacoTM, Ketjen black (KB), carbon nanotubes (CNTs), graphite KS6, graphite KS15, graphite SFG15, graphite SFG6, nanocarbon fiber (VGCF), superconducting carbon, carbon dots, graphene, polyacetylene, polyaniline, polypyridine, polythiophene, polythiourea, indium tin oxide (ITO) or at least one of the groups consisting of polyphenylene derivatives and mixtures thereof.

[0047] The adhesive is mainly used to achieve the bonding effect of the conductive adhesive 3. In addition, the adhesive can also maintain the stability of the conductive adhesive 3 material and provide a certain amount of electronic conduction to reduce the internal resistance of the conductive adhesive 3. As an example, the adhesive can be at least one of a group consisting of water-based acrylic resin, polyvinyl butyral (PVB), polyacrylonitrile, polyvinyl chloride, polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polyethylene imine, polymethyl methacrylate, polybutyl acrylate, polyvinyl pyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate (EVA), polyarylate, polystyrene acyl p-phenylenediamine polyethylene oxide, polypropylene oxide, polyoxymethylene, polyvinyl alcohol (PVA), SD-3, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, polyethylene, polytetrafluoroethylene (PTFE), polypropylene, styrene butadiene rubber (SBR), acrylic (ester) styrene butadiene rubber, epoxy resin or nylon and a mixture thereof.

[0048] The reinforcing agent is a filler mainly used to improve the strength of the soft tab 111. As an example, the reinforcing agent can be conductive metal powder, metal fiber: at least one of aluminum, copper, nickel, silver, palladium, tin, zinc, manganese, cobalt, magnesium, vanadium, and iron.

[0049] The dispersant is used to effectively disperse the components of the conductive adhesive 3, improve the preparation efficiency of the conductive adhesive 3 slurry, and further improve the conductivity of the conductive adhesive 3. As an example, the dispersant can be at least one of the group consisting of polyvinyl pyrrolidone (PVP), carboxymethyl cellulose (CMC), hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, polyvinyl alcohol, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, polyacrylic acid (PAA), sodium polyacrylate (PAANa), modified styrene maleic acid copolymer (SMA), and mixtures thereof.

[0050] The mass fractions of the components of the conductive adhesive 3 are as follows: the conductive agent accounts for 2%-5%, the adhesive accounts for 22%-25%, the reinforcing agent accounts for 7%-70%, and the dispersant accounts for 1%-3%.

[0051] The manufacturing steps of the battery cell 100 of this embodiment are as follows:

[0052] S101, slurry preparation: mixing materials according to the proportion of material components of the conductive adhesive 3 to prepare conductive adhesive 3 slurry;

[0053] S102, brushing glue: brushing conductive slurry evenly on the surface of the soft tab 111 according to the design of the thickness and area of ​​the conductive glue 3, to preliminarily form the conductive glue 3;

[0054] S103, baking: drying the brushed conductive paste to prevent the conductive paste from shifting during the subsequent winding or lamination process and contaminating the battery cell 100 body;

[0055] S104, hot pressing: after the electrode pieces are made into a core roll or a core stack, hot pressing is performed to melt the adhesive in the conductive adhesive 3 so as to achieve connection between the soft electrode tabs 111 and between the soft electrode tabs 111 and the hard electrode tabs 2.

[0056] According to the battery cell 100 of the embodiment of the present application, the soft pole ear 111 and the hard pole ear 2 and the multiple soft pole ears 111 are connected by the conductive adhesive 3, so that the multiple soft pole ears 111 and the soft pole ear 111 and the hard pole ear 2 can transmit current through the conductive adhesive 3. In this way, the surface of the soft pole ear 111 and the hard pole ear 2 is relatively flat as a whole, avoiding the protrusions and burrs that may be generated at the welding mark when the welding scheme is adopted in the related art, and also eliminating the adhesive tape attached to the protruding part to prevent the protrusion from piercing the external aluminum-plastic film. The saved protrusion thickness and adhesive tape thickness can improve the space utilization rate of the battery head to improve the battery energy density, and can avoid the protrusion piercing the adhesive tape and other structures in the related art, thereby avoiding internal short circuit of the battery and improving safety.

[0057] In addition, compared with the solution of welding the soft pole ear 111 to the hard pole ear 2 in the related art, the welding slag and metal particles generated by welding can be prevented from contacting the battery cell 100, thereby causing serious self-discharge of the finished battery and poor electrical performance. It can also avoid the problem of cold welding caused by aging, wear, insufficient power of welding equipment, etc., to avoid chip falling, affect the battery charging and discharging path, and ensure the battery charging and discharging performance.

[0058] It should be noted that in the related art of connecting the soft pole ear 111 and the hard pole ear 2 by welding, the thickness of the protrusion generated by the welding is 100 to 200 microns, but in this embodiment, no welding is used and no protrusion is formed. Taking a battery model with a design capacity of 3930mAh, a 4V system, a thickness (PPG) of 4.1mm, a width (after folding) of 84.9mm, and a height of 64.5mm as an example, the solution of this embodiment can improve the volume specific energy density by 0.16%-0.31% due to the elimination of the protrusion;

[0059] In addition, the thickness of the adhesive tape set on the protruding part of the related solution is about 15-20 microns, while in this embodiment, the adhesive tape on the back of the soft pole ear 111 can be eliminated. Taking a battery model with a design capacity of 3930mAh, a 4V system, a thickness (PPG) of 4.1mm, a width (after folding) of 84.9mm, and a height of 64.5mm as an example, the solution of this embodiment can increase the volume energy density by 0.023% to 0.031%.

[0060] In some embodiments, reference Figure 2 and Figure 3 , the hard pole ear 2 and the soft pole ear 111 have an overlapping area, and the projection of the first glue layer 31 in the reference plane is within the projection of the overlapping area in the reference plane, wherein the reference plane is parallel to the flat surface on either side of the battery cell 100 along the thickness direction, and the flat surface here refers to the flat area in the outer surface of the battery cell 100, and the flat area is located on both sides of the battery cell 100 along the thickness direction. In other words, the area of ​​the first glue layer 31 is smaller than the area of ​​the overlapping area, so that it can be prevented that the amount of glue applied in each glue-applying gap is too much during the glue-applying process, resulting in overflow of the conductive glue 3 when the hard pole ear 2 and the soft pole ear 111 are stacked.

[0061] In some embodiments, the area of ​​the overlap region is 0.3 mm 2 -500mm 2 , for example, the area of ​​the overlap region is 0.3 mm 2 , 1mm 2 , 2mm 2 , 5mm 2 , 10mm 2 , 25mm 2 , 50mm 2 , 100mm2 , 150mm 2 , 200mm 2 , 250mm 2 、300mm 2 、350mm 2 , 400mm 2 , 450mm 2 or 500mm 2 Of course, this application does not limit this, and the area of ​​the overlapping area can be reasonably selected within the above range according to actual needs. In this way, on the one hand, it is avoided that the area of ​​the overlapping area is too small, for example, less than 0.3mm 2 When the connection area is too small, the connection between the soft pole ear 111 and the hard pole ear 2 is unstable. On the other hand, the overlapping area is prevented from being too large, for example, greater than 500mm. 2 When the thickness of the overlapping area is large, it occupies too much space in the head of the battery, and the effect of improving the current capacity is not obvious.

[0062] In some embodiments, the ratio of the area of ​​the first adhesive layer 31 to the area of ​​the overlapping region is in the range of 0.5-0.9. For example, the ratio of the area of ​​the first adhesive layer 31 to the area of ​​the overlapping region is 0.5, 0.6, 0.7, 0.8 or 0.9. Of course, the present application does not limit this, and the ratio of the area of ​​the first adhesive layer 31 to the area of ​​the overlapping region can be reasonably selected within the above range according to actual needs. In this way, on the one hand, it can be avoided that the ratio of the area of ​​the first glue layer 31 to the area of ​​the overlapping area is too small, for example, less than 0.5, resulting in unreliable connection between each soft pole ear 111 and between adjacent soft pole ears 111 and hard pole ears 2, easy to debond and separate, and large resistance at the conductive glue 3 and poor current carrying capacity. On the other hand, it can be avoided that the ratio of the area of ​​the first glue layer 31 to the area of ​​the overlapping area is too large, for example, greater than 0.9, resulting in excessive connection area between each soft pole ear 111 and between the soft pole ear 111 and the hard pole ear 2. During the production process, too much glue is applied in each glue coating gap, resulting in overflow of the conductive glue 3 when the hard pole ear 2 and the soft pole ear 111 are stacked.

[0063] In some embodiments, the thickness of the first adhesive layer 31 ranges from 1 μm to 10 μm. For example, the thickness of the first adhesive layer 31 may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm. Preferably, the thickness of the first adhesive layer 31 is 1 μm to 6 μm. Of course, the present application does not limit this, and the thickness of the first adhesive layer 31 can be reasonably selected within the above range according to actual needs. In this way, it can be avoided that when the thickness of the first adhesive layer 31 is too small, for example, less than 1 μm, the bonding effect is poor, and the resistance of the conductive adhesive 3 is large, and it can also be avoided that when the thickness of the first adhesive layer 31 is too large, for example, greater than 10 μm, the overall thickness after the soft pole ear 111 and the hard pole ear 2 are connected is too large, and the battery head space is too large.

[0064] In some embodiments, the ratio of the total thickness of the plurality of first adhesive layers 31 to the sum of the thickness of the plurality of soft pole ears 111 and the plurality of first adhesive layers 31 is in the range of 0.01-0.5. For example, the ratio of the total thickness of the plurality of first adhesive layers 31 to the sum of the thickness of the plurality of soft pole ears 111 and the plurality of first adhesive layers 31 is 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4 or 0.5. Preferably, the ratio of the total thickness of the plurality of first adhesive layers 31 to the sum of the thickness of the plurality of soft pole ears 111 and the plurality of first adhesive layers 31 is in the range of 0.05-0.2. Of course, the present application is not limited thereto. The ratio of the total thickness of the plurality of first adhesive layers 31 to the sum of the thickness of the plurality of soft pole ears 111 and the plurality of first adhesive layers 31 can be reasonably selected within the above range according to actual needs. In this way, the current flow capacity of the soft pole ear 111 can be guaranteed, and the excessive thickness of the soft pole ear 111 can be avoided, which will occupy too much internal space of the battery.

[0065] In some embodiments, reference Figure 3 and Figure 4 The conductive glue 3 also includes a second glue layer 32. At least part of the multiple soft pole ears 111 is provided with a receiving structure. For example, some of the soft pole ears 111 constituting the pole ears may be provided with a receiving structure, or all of the soft pole ears 111 constituting the pole ears may be provided with a receiving structure. The receiving structure is used to accommodate the second glue layer 32. By providing the receiving structure, the capacity of the conductive glue 3 at the soft pole ear 111 at the receiving structure can be increased, and the contact area between the soft pole ear 111 and the conductive glue 3 can be increased. On the one hand, the connection stability of the conductive glue 3 and the soft pole ear 111 can be improved to enhance the structural stability of the soft pole ear 111. On the other hand, the current carrying capacity of the conductive glue 3 can be improved, the resistance can be reduced, and the heat generation can be reduced.

[0066] In some embodiments, reference Figure 3 and Figure 3a The accommodation structure is formed along the thickness direction of the soft pole ear 111 (such as Figure 1The connecting hole 112 (in the Z direction shown in the figure) penetrates the soft pole ear 111, and the conductive glue 3 also fills the connecting hole 112. In this way, the connection area between the soft pole ear 111 and the conductive glue 3 can be increased without increasing the overall thickness of the soft pole ear 111, so as to increase the bonding stability of the conductive glue 3 on the soft pole ear 111, thereby improving the structural stability of the soft pole ear 111 itself, and the connection stability between the soft pole ear 111 and the hard pole ear 2.

[0067] In some embodiments, the first adhesive layer 31 is disposed at both ends of the second adhesive layer 32 , and the two ends of the second adhesive layer 32 are connected to the first adhesive layer 31 respectively.

[0068] For example, the plurality of second glue coating gaps are, from top to bottom, the second glue coating gap a, the second glue coating gap b, the second glue coating gap c, and the second glue coating gap d, and the first glue layer 31 is provided in the second glue coating gap a, the second glue coating gap b, the second glue coating gap c, and the second glue coating gap d, and the two ends of the second glue layer 32 in the connecting hole 112 on the soft pole ear 111 between the second glue coating gap a and the second glue coating gap b can be connected to the first glue layer 31 in the second glue coating gap a and the second glue coating gap b, the two ends of the second glue layer 32 in the connecting hole 112 on the soft pole ear 111 between the second glue coating gap b and the second glue coating gap c can be connected to the first glue layer 31 in the second glue coating gap b and the second glue coating gap c, and the two ends of the second glue layer 32 in the connecting hole 112 on the soft pole ear 111 between the second glue coating gap c and the second glue coating gap d can be connected to the first glue layer 31 in the second glue coating gap c and the second glue coating gap d.

[0069] In this way, the glue coating method of this embodiment allows the conductive glue 3 to fill each second glue coating gap and the connecting hole 112 on each soft pole ear 111, which can increase the contact area between the conductive glue 3 and the soft pole ear 111, enhance the connection force between the soft pole ears 111, improve the overall anti-drop performance of the soft pole ear 111, and enhance its safety.

[0070] In other embodiments, reference Figure 3 The first end of the second adhesive layer 32 is provided with the first adhesive layer 31 , the first end of the second adhesive layer 32 is connected to the first adhesive layer 31 , and the second end is connected to the soft electrode ear 111 .

[0071] In other words, one of the two second glue-coated gaps on both sides of any soft electrode tab 111 having a connecting hole 112 is provided with a first glue layer 31, and the other is not provided with the first glue layer 31, and the conductive glue 3 in the connecting hole 112 also diffuses and connects the soft electrode tab 111 on the other side of the second glue-coated gap that is not provided with the first glue layer 31. That is to say, in this embodiment, not every second glue-coated gap is provided with a first glue layer 31, but a plurality of second glue-coated gaps are provided with the first glue layer 31.

[0072] For example, the plurality of second glue coating gaps are, from top to bottom, the second glue coating gap a, the second glue coating gap b, the second glue coating gap c, and the second glue coating gap d. In this embodiment, a first glue layer 31 can be arranged in the second glue coating gap a and the second glue coating gap c. At this time, a connecting hole 112 is arranged on the soft pole ear 111 on the upper side of the second glue coating gap b, so that when coating, the conductive glue 3 in the second glue coating gap a can diffuse downward to the second glue coating gap b through the connecting hole 112, and connect the soft pole ears 111 on the upper and lower sides of the second glue coating gap b. Correspondingly, a connecting hole 112 is arranged on the soft pole ear 111 on the upper side of the second glue coating gap d, so that when coating, the conductive glue 3 in the second glue coating gap c can diffuse downward to the second glue coating gap d through the connecting hole 112, and connect the soft pole ears 111 on the upper and lower sides of the second glue coating gap d.

[0073] In this way, the glue coating method in this embodiment can reduce the use of conductive glue 3, save costs, and improve the drying rate of conductive glue 3 in the production process; and the conductive glue 3 in the connecting hole 112 and the soft pole ear 111 are in point contact, which is easy to discharge bubbles and reduce the influence of bubbles on the connection, and the connection force is stronger. Moreover, the conductive glue 3 in the connecting hole 112 is more difficult to contact the electrolyte than the conductive glue 3 between the soft pole ears 111, which improves the corrosion resistance of this place and greatly improves the safety performance and cycle life of the battery.

[0074] In some embodiments, the thickness of the second adhesive layer 32 at the connecting hole 112 ranges from 5μm to 20μm. For example, the thickness of the second adhesive layer 32 can be 5μm, 6μm, 7μm, 8μm, 10μm, 12μm, 15μm, 18μm or 20μm. Of course, the present application is not limited to this, and the thickness of the second adhesive layer 32 at the connecting hole 112 can be reasonably selected within the above range according to actual needs. Preferably, the thickness of the second adhesive layer 32 at the connecting hole 112 ranges from 7μm to 15μm. In this way, it is possible to ensure that there is sufficient connection contact area between the conductive adhesive 3 and the soft pole ear 111, improve the connection force between the soft pole ear 111, improve the anti-drop performance of the soft pole ear 111, and improve its safety.

[0075] It should be noted that, when conductive glue 3 is provided in multiple second glue coating gaps, the thickness of the conductive glue 3 at the connecting hole 112 is the depth of the connecting hole 112; when conductive glue 3 is provided in multiple second glue coating gap partitions, the thickness of the conductive glue 3 at the connecting hole 112 refers to the sum of the depth of the connecting hole 112 and the width of the second glue coating gap connected to the connecting hole 112 and without the conductive glue 3 provided.

[0076] In some embodiments, the ratio of the total volume of all the second adhesive layers 32 to the total volume of all the conductive adhesives 3 is in the range of 0.5-0.9. For example, the ratio of the total volume of the second adhesive layer 32 to the total volume of all the conductive adhesives 3 can be 0.5, 0.6, 0.7, 0.8 or 0.9. Of course, the present application does not limit this. The ratio of the total volume of the second adhesive layer 32 to the total volume of all the conductive adhesives 3 can be reasonably selected within the above range according to actual needs. In this way, it can be avoided that the total volume of the conductive adhesive 3 at the connecting hole 112 is too small when the ratio of the total volume of the second adhesive layer 32 to the total volume of all the conductive adhesives 3 is too small, such as less than 0.5, so that the soft pole ears 111 on both sides of the second adhesive gap where the conductive adhesive 3 is not set are not connected stably; and it can also be avoided that the total volume of the second adhesive layer 32 to the total volume of all the conductive adhesives 3 is too large, such as greater than 0.9, so that the total volume of the conductive adhesive 3 in the second adhesive gap is too small, so that the soft pole ears 111 on both sides of the second adhesive gap where the conductive adhesive 3 is set are not connected stably.

[0077] In some embodiments, reference Figure 3 The connecting holes 112 on any two adjacent soft tabs 111 are arranged along the first direction (eg Figure 1 ) and / or a second direction (eg, Figure 1 In this way, the communicating holes 112 are arranged in various ways to meet different needs.

[0078] Optionally, the communication holes 112 on each soft electrode tab 111 can be arranged in order or in disorder. In this way, the communication holes 112 can be arranged in various ways to meet different needs.

[0079] refer to Figure 4 In addition to the above-mentioned solution of setting the accommodation structure as the connecting hole 112, the embodiment of the present application also provides another structure of the accommodation structure. In this embodiment, the accommodation structure is formed as a groove 113 that is recessed along the thickness direction of the soft pole ear 111, and the second adhesive layer 32 also fills the groove 113, so that the capacity of the conductive adhesive 3 can be increased, and the connection area between the conductive adhesive 3 and the soft pole ear 111 can be increased.

[0080] In some embodiments, reference Figure 4 Each soft electrode ear 111 is provided with a plurality of grooves 113, and the plurality of grooves 113 are spaced apart from each other, or at least some of the plurality of grooves 113 are arranged continuously, for example Figure 3As shown, the multiple grooves 113 on each soft pole ear 111 are continuously distributed, so that the soft pole ear 111 is formed into a wave shape. In this way, the capacity of the conductive glue 3 can be increased, and the connection strength between the soft pole ears 111 and between the soft pole ears 111 and the hard pole ears 2 can be strengthened. In addition, the conductive glue 3 filled in the groove 113 can further improve the folding performance of the soft pole ear 111, reduce the risk of short circuit in the battery cell 100, and improve the safety performance and cycle life of the battery cell 100.

[0081] In some embodiments, the ratio of the volume of the second adhesive layer 32 in all the grooves 113 to the volume of all the conductive adhesives 3 is 0.1-0.5. For example, the ratio of the volume of the second adhesive layer 32 in all the grooves 113 to the volume of all the conductive adhesives 3 is 0.1, 0.2, 0.3, 0.4 or 0.5. Of course, the present application does not limit this. The ratio of the volume of the second adhesive layer 32 in all the grooves 113 to the volume of all the conductive adhesives 3 can be reasonably selected within the above range according to actual needs. In this way, it is beneficial to strengthen the connection strength between the soft pole ears 111 and between the soft pole ears 111 and the hard pole ears 2, improve the folding performance of the soft pole ears 111, reduce the risk of short circuit in the battery cell 100, and improve the safety performance and cycle life of the battery cell 100.

[0082] The battery of the second embodiment of the present application is described below.

[0083] The battery of this embodiment may include: a housing and a battery cell 100 of the above embodiment. The battery cell 100 is disposed in the housing, wherein the soft pole ear 111 of the battery cell 100 is connected to the electrode on the housing through the hard pole ear 2, for example, the positive soft pole ear is connected to the positive pole of the housing through the positive pole adapter, and the negative soft pole ear is connected to the negative pole of the housing through the negative pole adapter.

[0084] The battery of the embodiment of the present application is provided with the battery cell 100 of the above embodiment. Since no protrusion is generated at the connection part after the soft pole ear 111 and the hard pole ear 2 are connected, and the adhesive tape provided on the back of the soft pole ear 111 in the related art to prevent the protrusion after the soft pole ear 111 is folded and pierces the external aluminum-plastic film is omitted, it is beneficial to save the head space of the battery, improve the space utilization rate inside the battery, and thus improve the energy density of the battery. It can also avoid the generation of welding slag and metal particles to prevent the welding slag and metal particles from contacting the battery cell 100 and causing serious self-discharge of the finished battery and poor electrical performance. It can also avoid the phenomenon of cold welding generated in the welding scheme, avoid chip falling, and affect the charge and discharge path of the battery, thereby ensuring the charge and discharge performance and safety of the battery.

[0085] The following describes an electrical device according to an embodiment of the third aspect of the present application.

[0086] The power-consuming device of this embodiment may be a mobile phone, a tablet computer, a laptop computer, a new energy vehicle, a smart watch, a communication base station, etc. The power-consuming device may include: a device body and the battery in the above embodiment. The device body has a battery compartment, the battery may be arranged in the battery compartment, and the battery is electrically connected to the device body.

[0087] According to the electrical device of the embodiment of the present application, by setting the battery in the above embodiment, the battery can have better charging and discharging performance, can better power the electrical device, and has higher safety, which is conducive to improving the user experience.

[0088] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0089] It should be noted that the embodiments represented by "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments that are explicitly or not explicitly described.

[0090] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0091] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0092] Additionally, cavity-relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Cavity-relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the cavity-relative descriptors used herein may likewise be interpreted accordingly.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: A first pole piece, a diaphragm, and a second pole piece, wherein the first pole piece, the diaphragm, and the second pole piece are stacked, wherein the first pole piece and the second pole piece have opposite polarities, the first pole piece comprises a first current collector, the first pole piece comprises a plurality of soft pole tabs protruding from the first current collector, and the plurality of soft pole tabs are stacked; A hard pole tab, the hard pole tab being stacked and electrically connected to the outermost one of the plurality of soft pole tabs; The conductive adhesive comprises a first adhesive layer, wherein at least a portion of the space between two adjacent soft tabs is filled with the first adhesive layer, and a portion of the space between the adjacent hard tab and the adjacent soft tab is filled with the first adhesive layer.

2. The battery cell according to claim 1, characterized in that: The hard pole ear and the soft pole ear have an overlapping area, and the projection of the first glue layer on the reference plane is within the projection of the overlapping area on the reference plane. The reference surface is parallel to a flat surface on any side of the battery cell along a thickness direction.

3. The battery cell according to claim 2, characterized in that: The area of ​​the overlapping region is 0.3 mm 2 -500mm 2 and / or, The ratio of the area of ​​the first adhesive layer to the area of ​​the overlapping region is in the range of 0.5-0.9; and / or, The thickness of the first adhesive layer ranges from 1 μm to 10 μm; and / or, The ratio of the total thickness of the first adhesive layer to the sum of the thicknesses of the plurality of soft tabs and the plurality of the first adhesive layers is in the range of 0.01-0.

5.

4. The battery cell according to claim 1, characterized in that: The conductive adhesive further includes a second adhesive layer, and at least part of the plurality of soft tabs is provided with a receiving structure, and the receiving structure is filled with the second adhesive layer.

5. The battery cell according to claim 4, characterized in that: The accommodating structure is formed as a communicating hole penetrating the soft electrode tab along the thickness direction of the soft electrode tab.

6. The battery cell according to claim 5, characterized in that: The first adhesive layer is disposed at both ends of the second adhesive layer, and the two ends of the second adhesive layer are respectively connected to the first adhesive layer.

7. The battery cell according to claim 5, characterized in that: The first adhesive layer is disposed at the first end of the second adhesive layer, the first end of the second adhesive layer is connected to the first adhesive layer, and the second end of the second adhesive layer is connected to the soft electrode tab.

8. The battery cell according to claim 5, characterized in that: The thickness of the second adhesive layer is in the range of 5 μm to 20 μm; and / or, The ratio of the total volume of all the second adhesive layers to the total volume of all the conductive adhesives is in the range of 0.5-0.

9.

9. The battery cell according to claim 5, characterized in that: The communicating holes on any two adjacent soft electrode ears are staggered or aligned with each other along the first direction and / or the second direction.

10. The battery cell according to claim 4, characterized in that: The accommodating structure is a groove formed on the surface of the soft electrode tab, and the second adhesive layer is filled in the groove.

11. The battery cell according to claim 10, characterized in that: The ratio of the volume of the second adhesive layer in all the grooves to the volume of all the conductive adhesives is 0.1-0.

5.

12. A battery, characterized in that: include: shell; The battery cell according to any one of claims 1 to 11, wherein the battery cell is arranged in the casing.

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