WO2020125696A1 - 电芯及电池 - Google Patents

电芯及电池 Download PDF

Info

Publication number
WO2020125696A1
WO2020125696A1 PCT/CN2019/126424 CN2019126424W WO2020125696A1 WO 2020125696 A1 WO2020125696 A1 WO 2020125696A1 CN 2019126424 W CN2019126424 W CN 2019126424W WO 2020125696 A1 WO2020125696 A1 WO 2020125696A1
Authority
WO
WIPO (PCT)
Prior art keywords
battery cell
sealing section
sealing
packaging
area
Prior art date
Application number
PCT/CN2019/126424
Other languages
English (en)
French (fr)
Inventor
王烽
陈宇
Original Assignee
宁德新能源科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Publication of WO2020125696A1 publication Critical patent/WO2020125696A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0459—Cells or batteries with folded separator between plate-like electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/184—Sealing members characterised by their shape or structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/552—Terminals characterised by their shape
    • H01M50/553—Terminals adapted for prismatic, pouch or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2200/00—Safety devices for primary or secondary batteries
    • H01M2200/20—Pressure-sensitive devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/117—Inorganic material
    • H01M50/119—Metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/121—Organic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
    • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
    • H01M50/129—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers with two or more layers of only organic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/547—Terminals characterised by the disposition of the terminals on the cells
    • H01M50/55—Terminals characterised by the disposition of the terminals on the cells on the same side of the cell
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/552—Terminals characterised by their shape
    • H01M50/553—Terminals adapted for prismatic, pouch or rectangular cells
    • H01M50/557—Plate-shaped terminals
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This application relates to the technical field of electrochemical devices, in particular, to a battery cell and a battery.
  • Lithium-ion batteries have been widely used in various digital products, power tools, drones, energy storage systems, and automotive power systems because of their advantages of high energy density, long cycle life, and high cost performance.
  • the packaging reliability of soft-packed lithium-ion batteries has always been paid attention by researchers. Especially the soft-packed lithium-ion batteries used in energy storage systems have stricter requirements on the long-term reliability of the package.
  • the currently widely used heads (such as flat heads or oblique heads) and their packaging technologies encapsulate lithium-ion batteries.
  • the resulting lithium-ion battery has a low encapsulation strength and poor creep resistance. Low life (generally less than three years), unable to meet the long-term reliability requirements of lithium-ion batteries, which limits the application of lithium-ion batteries in the field of long-term energy storage and areas with high requirements for safety and reliability.
  • the head also brings processing problems and wear problems.
  • the packaging process is a key process in the production of soft-packed lithium-ion batteries, especially the side sealing and vacuum packaging processes, which are critical to the safety and reliability of the battery. Therefore, it is necessary to develop a packaging technology that can meet the long-term reliability requirements of packaging.
  • one aspect of the present application is to propose a battery cell that has better packaging reliability and higher safety.
  • the battery cell includes a battery cell body and a packaging bag containing the battery cell body, the packaging bag includes a packaging portion, the packaging portion includes a sealing area, and the sealing area includes a recessed portion, The recessed portion is provided on an end surface of the sealing region close to the cell body, and the recessed portion is recessed away from the cell body.
  • the thermal stress caused by the temperature gradient can be eliminated, the mechanical stress on the packaging bag caused by the right angle of the head can be eliminated, and the battery cell can be eliminated
  • the mechanical stress caused by the body can improve the morphology of the overflowing area of the encapsulation part, improve the structural defects of the overflowing area, and also reduce the residual amount of electrolyte in the encapsulation part, preventing the electrolyte from Internally damaging the encapsulation portion can greatly improve the encapsulation strength of the encapsulation portion of the cell, thereby improving the packaging reliability and safety issues of the cell.
  • the recessed part can transfer the stress point of the packaging part of the battery cell obtained by using the traditional head and its packaging technology, and can withstand a greater tensile force.
  • the application can improve the packaging strength of the packaging portion of the battery cell by providing the recessed portion in the packaging portion, which can further improve the packaging reliability and safety of the battery cell.
  • the packaging bag includes a first shell and a second shell, the first shell includes a first bonding layer, the second shell includes a second bonding layer, and the first bonding The layer is combined with the second bonding layer to form the sealing area and a receiving space for receiving the cell body, the recessed portion is connected to the receiving space, and the recessed portion faces away from the receiving space Recessed.
  • the sealing area includes a first sealing section and a second sealing section, one end of the first sealing section is connected to the second sealing section, and the other end of the first sealing section Recessed toward the direction of the second sealing section to form the recess.
  • the length of the sealing area is L1
  • the length of the second sealing section is L2
  • L1/L2 is greater than or equal to 1.2:1, and less than or equal to 10:1.
  • the maximum thickness of the first sealing section is T1
  • the thickness of the second sealing section is T2.
  • T1/T2 is greater than or equal to 1.5:1 and less than or equal to 4:1.
  • the longitudinal cross-sectional area of the first sealing section is N
  • the longitudinal cross-sectional area of the second sealing section is K
  • N/K is greater than zero
  • the thickness of the first sealing section gradually increases first and then gradually decreases in a direction close to the receiving space.
  • At least part of the contact surface between the recessed portion and the receiving space is a smooth surface.
  • At least part of the contact surface between the recessed portion and the receiving space is an arc-shaped surface.
  • the bottom of the recessed portion includes a protrusion that protrudes toward the receiving space.
  • the sealing area further includes a third sealing section, the third sealing section is disposed between the first sealing section and the second sealing section, extending along the receiving space In the direction, the thickness of the third sealing section gradually increases.
  • the length of the second sealing section is L2
  • the length of the third sealing section is L3
  • L2/L3 is greater than 0 in a direction close to the receiving space.
  • Another aspect of the present application is to propose a battery that has better packaging reliability and higher safety.
  • the battery includes a battery cell and a case that houses the battery cell, the battery cell includes a battery cell body, and a packaging bag that houses the battery cell body, and the packaging bag includes a packaging portion.
  • the packaging portion includes a sealing area, wherein the sealing area includes a recessed portion, the recessed portion is disposed on an end surface of the sealing area near the cell body, and the recessed portion faces away from the cell body The direction is recessed.
  • the morphology of the glue spilling area of the packaging portion can be improved, the structural defects of the glue spilling area can be improved, and the packaging portion can also be reduced
  • the residual amount of electrolyte can greatly improve the packaging strength of the packaging part of the battery cell, thereby improving the packaging reliability and safety of the battery cell.
  • FIG. 1 shows a schematic structural diagram of a battery cell according to an embodiment of the present application
  • FIG. 2 shows a partially enlarged schematic view of the sealing area A in FIG. 1;
  • FIG. 3 shows a cross-sectional view of the sealing area in FIG. 1 along the section line B-B;
  • FIG. 4 shows a cross-sectional view of the sealing area in FIG. 1 along the cross-sectional line C-C or D-D;
  • FIG. 5 shows the tensile stress-strain curve of the outer layer (PA or PET) of the aluminum-plastic film in FIG. 4;
  • FIG. 6 shows the tensile stress-strain curve of the middle layer (Al) of the aluminum-plastic film in FIG. 4;
  • FIG. 8 shows the tensile stress-strain curve of the sealing area of the cell obtained by using a conventional flat head
  • FIG. 9 shows the tensile stress-strain curve of the sealing area of the battery cell obtained by the packaging technology of the present application, the sealing area is obtained by cutting along the cross-sectional line C-C or D-D shown in FIG. 1;
  • FIG. 10 shows a partial cross-sectional view of a sealing area of a battery cell according to another embodiment of the present application.
  • the cross-sectional view is obtained by cutting the sealing area along the direction of section line C-C or D-D shown in FIG. 1;
  • FIG. 11 shows an enlarged schematic view of the partial structure in FIG. 10;
  • FIG. 12 shows the tensile stress-strain curve of the sealing area in FIG. 10
  • FIG. 13 shows a partial cross-sectional view of a sealing region of a battery cell according to another embodiment of the present application.
  • the cross-sectional view is obtained by cutting the sealing region along the cross-sectional line C-C or D-D shown in FIG. 1;
  • FIG. 14 shows the tensile stress-strain curve of the sealing area in Example 1 of the present application.
  • FIG. 16 shows a partial cross-sectional view of the sealing area of the battery cell according to the third embodiment of the present application.
  • the cross-sectional view is obtained by cutting the sealing area along the cross-sectional line C-C or D-D shown in FIG. 1;
  • FIG. 17 shows the tensile stress-strain curve of the sealing area in FIG. 16.
  • Cell 110 Cell body 111, pole ear 112,
  • the battery cell 110 and the battery according to the embodiments of the present application will be described below with reference to FIGS. 1 to 17.
  • the battery cell 110 includes a battery cell body 111 and a packaging bag 120 that houses the battery cell body 111.
  • the cell 110 may include a tab 112 electrically connected to the cell body 111, and the tab 112 passes through the packaging bag 120.
  • the packaging bag 120 may include an encapsulation portion 121, and the encapsulation portion 121 may include a sealing area, as shown in FIGS. 3 and 4, the sealing area may include a recess 160, which is disposed in the sealing area near the cell body 111 On the end surface of the recess, the recess 160 is recessed away from the cell body 111.
  • the recessed direction of the recessed portion 160 may be understood as a part of the surface of the sealing region recessed toward its own interior to form the recessed portion 160.
  • the temperature gradient can be eliminated Thermal stress, eliminate the mechanical stress caused by the right angle of the head on the packaging bag 120, and eliminate the mechanical stress caused by the cell body 111, thereby improving the morphology of the overflowing area of the packaging part 121 and improving the structural defects of the overflowing area , Can also reduce the residual amount of electrolyte in the packaging part 121, to prevent the electrolytic solution from damaging the packaging part 121 from the inside during long-term use of the battery cell 110, thereby greatly improving the packaging strength of the packaging part 121 of the battery cell 110, thereby improving the battery cell 110 packaging reliability and safety issues.
  • the concave part 160 can transfer the stress point of the packaging part 121 and can withstand a greater tensile force, which also verifies that the application provided the concave part in the packaging part 121 160 can improve the packaging strength of the packaging portion 121 of the battery cell 110, and can further improve the packaging reliability and safety of the battery cell 110.
  • the packaging bag 120 may include a first shell 140 and a second shell 150.
  • the first housing 140 includes a first bonding layer 141
  • the second housing 150 includes a second bonding layer 151.
  • the first bonding layer 141 and the second bonding layer 151 are combined to form a sealed area and contain the cell body 111.
  • the concave portion 160 is connected to the accommodating space 130, and the concave portion 160 is recessed in a direction away from the accommodating space 130.
  • the structural stability of the encapsulation portion 121 can be improved, which facilitates the packaging of the battery cell 110, and at the same time, it is advantageous to construct a sealed area between the first bonding layer 141 and the second bonding layer 151, and thereby construct a receiving space 130.
  • the first housing 140 may further include a first metal layer 142 and a first protective layer 143.
  • the first metal layer 142 is disposed on the first bonding layer 141 and the first Between protective layers 143.
  • the second housing 150 may also include a second metal layer 152 and a second protective layer 153, and the second metal layer 152 is disposed between the second bonding layer 151 and the second protective layer 153.
  • the material of the first protective layer 143 and/or the second protective layer 153 may be polyamide (PA), polyethylene terephthalate (PET) or a combination thereof, etc.
  • the material of the second metal layer 152 may be aluminum or steel, etc.
  • the material of the first bonding layer 141 and/or the second bonding layer 151 may be polypropylene (PP), polyethylene (PE), polyethylene naphthalate Ester (PEN) or a combination thereof.
  • the sealing area may include a first sealing section 1212 and a second sealing section 1213. Wherein, one end of the first sealing section 1212 is connected to the second sealing section 1213, and the end of the other end of the first sealing section 1212 faces the direction of the second sealing section 1213 to be recessed to form a recess 160.
  • the sealing area may be formed by hot pressing the first bonding layer 141 and the second bonding layer 151 by the head designed in this application. After the first bonding layer 141 and the second bonding layer 151 are melted by heat, When pressing, it can flow to a range where the pressure is smaller to form a rubber overflow area, and the rubber overflow area includes the first sealing section 1212.
  • the first sealing section is formed with a recess 160 at the interface connected to the containing space, which can improve the structural defects of the glue spill area, and can be transferred to use the traditional head and its
  • the stress point of the packaging part 121 of the battery cell 110 obtained by the packaging technology can further change the stress method of the packaging part 121, so that it can withstand greater pulling force and greatly improve the packaging strength of the packaging part 121 of the battery cell 110, and improve The reliability and safety of the packaging of the battery cell 110 and its battery.
  • the sealing area (including the first sealing section And the second sealing section) the length is L1, that is, the width of the head of the present application in the ab direction
  • the length of the second sealing section 1213 is L2, that is, from the position where the protrusion of the packaging portion 121 appears to the protrusion
  • L1/L2 is 1.2 or more and 10 or less. In some embodiments, L1/L2 is greater than or equal to 1.5 and less than or equal to 3, and at this time, the packaging portion 121 has higher packaging strength.
  • the position where the protrusion appears and the position where it disappears can be clearly seen from the surface appearance of the package portion 121 of the battery cell 110, or the two positions can be located on the battery cell 110 through the head of the present application Left on the package part 121.
  • the maximum thickness of the first sealing section 1212 is T1
  • the thickness of the second sealing section 1213 is T2
  • T1/T2 is 1.5 or more and 4 or less. In some embodiments, T1/T2 is greater than or equal to 1.5 and less than or equal to 2.5.
  • the packaging portion 121 has higher packaging strength.
  • the longitudinal cross-sectional area of the first sealing section 1212 is N
  • the longitudinal cross-sectional area of the second sealing section 1213 is K
  • N/K is greater than 0. And less than or equal to 100.
  • N/K is greater than or equal to 0.1 and less than or equal to 50.
  • N/K is greater than or equal to 0.1 and less than or equal to 1.
  • each cross-sectional area is measured by the following method: cut off the cross-sectional line CC or DD in FIG. 1 to obtain the cross-sectional shape of the package part 121, and then use the area of the Keyence 5000 (VHX-5000) microscope The measurement function measures N and K.
  • the packaging bag includes an upper aluminum plastic film (first shell) and a lower aluminum plastic film (second shell), and the upper aluminum plastic film and the lower aluminum plastic film are pressed together by a hot pressing process to form a sealed area for the accommodation space and the packaging part .
  • the upper aluminum plastic film and the lower aluminum plastic film respectively include an outer layer, a middle layer and an inner layer.
  • the material of the outer layer (the first protective layer 143 or the second protective layer 153) is PET or PA, and the middle layer (the first metal layer 142 or the first layer)
  • the material of the two-metal layer 152) is Al
  • the material of the inner layer (the first bonding layer 141 or the second bonding layer 151) is PP.
  • the outer layer, the middle layer, the inner layer of the aluminum plastic film, the sealing area made by the traditional head and the sealing area obtained by the packaging technology of the present application are respectively subjected to a tensile test to obtain a tensile stress-strain curve, that is, a tensile curve , As shown in Figure 5 to Figure 9.
  • the tension curve can be measured by the following method: the sample is clamped on the fixture of the universal material testing machine (Shenzhen Sansi Aspect Technology Co., Ltd., model UTM6101) and stretched at a speed of 30 mm/min. The tensile stress-strain curve is obtained.
  • the spline of the sealing area can be produced by the following method: Taking FIG. 1 as an example, the sealing area in FIG.
  • the tension curve of the sealing area obtained by the traditional head includes the L stage and the N1 stage.
  • the PA or PET, Al, PP and PP in the overflow area of the aluminum plastic film are slightly affected. Stretching; when stretching reaches a certain level (maximum value), the PP in the overflowing area undergoes plastic deformation and enters the N1 stage (PP-PP/PP-Al delamination occurs, and the failure is judged).
  • PA or PET, Al, PP no longer stretches, the tensile force is provided by the PP in the overflow area through its ductility, and the strength is very low. It can be seen from FIG.
  • the tension curve of the sealing area obtained by the packaging technology of the present application includes the L stage, the M stage and the N2 stage.
  • the PA or PET, Al, PP on the aluminum plastic film is slightly stretched.
  • the PP in the overflowing area is slightly stretched or may not be deformed; in the M stage, PA or PET, Al, and PP on the aluminum plastic film are severely plastically stretched, while the PP in the overflowing area is slightly
  • the tensile strength of PA, PET, and PP is better than that of Al.
  • the curve at this stage is the same as that of Al; when Al is broken, the tensile curve decays rapidly (vertically) and enters the N2 stage;
  • the difference in the N1 stage is that the tensile force in the N2 stage is provided by PP, PET or PA at the Al fracture on the aluminum plastic film, and the failure mode is provided by the PP-PP in the N1 stage (PP on the upper aluminum plastic film and PP on the lower aluminum plastic film)
  • the bonding layer) delamination or PP-Al delamination becomes the N2-stage aluminum-plastic film breaking.
  • At least part of the contact surface between the recess 160 and the accommodating space 130 is a smooth surface.
  • stress concentration can be avoided at the position of the contact surface, and the tensile force value that the package portion 121 can withstand can be further increased, so that the package strength of the package portion 121 can be further increased.
  • shape of the contact surface is not limited to this, as long as it can enhance the strength of the packaging portion 121, for example, in some embodiments, at least the contact surface between the recess 160 and the accommodating space 130 Part is curved surface.
  • the recessed portion 160 may have a round V shape, a U shape, a pocket shape, or the like, which is not limited in this application.
  • the thickness of the first sealing section 1212 gradually increases Large, and then gradually reduced. As shown in FIG. 10 in the direction from b to a, the thickness of the first sealing section 1212 gradually increases first, and when its thickness increases to the maximum, the thickness of the first sealing section 1212 begins to gradually decrease again.
  • the bottom of the recessed portion 160 includes a protrusion 161 that protrudes toward the receiving space 130.
  • the shape of the bottom of the recessed portion 160 is a tiny M-shape.
  • the sealing area may further include a third sealing section 1214.
  • the third sealing section 1214 is disposed between the first sealing section 1212 and the second sealing section 1213, along the direction close to the accommodation space 130 (as shown in the direction b to a in FIG. 13), the third sealing section 1214
  • the thickness gradually increases.
  • the length of the second sealing section 1213 is L2
  • the length of the third sealing section 1214 is L3 in the direction close to the accommodation space 130, that is, from the position where the thickness of the sealing area gradually increases to the appearance of the protrusion
  • the length between the positions, L2/L3 is greater than or equal to 0.
  • L2/L3 is greater than or equal to 0.5 and less than or equal to 2.
  • the inclination angle of the third sealing section 1214 is ⁇ , and the length of the third sealing section 1214 is L3.
  • the maximum thickness of the third sealing section 1214 is max(T1)
  • the minimum thickness of the third sealing section 1214 is min(T1)
  • max(T1) min(T1)+L3 ⁇ tan ⁇ , where , 0° ⁇ 2°.
  • the present application also discloses a battery obtained according to the above battery cell, the battery includes a battery cell 110 and a housing that houses the battery cell 110, the battery cell 110 includes a battery cell body 111 and a packaging bag 120 that houses the battery cell body 111
  • the bag 120 includes an encapsulation portion 121 including a sealing area, and the sealing area includes a recessed portion 160 provided on an end surface of the sealing area close to the cell body 111, and the recessed portion 160 is recessed away from the cell body 111 .
  • the battery cell 110 according to an embodiment of the present application will be described in detail below with reference to the drawings in specific embodiments. It should be understood that the following description is only an exemplary illustration, not a limitation of the present application.
  • the packaging bag 120 is an aluminum-plastic film.
  • the aluminum-plastic film includes an outer layer, a middle layer, and an inner layer.
  • the outer layer is made of PA, PET, or a composite material of the two.
  • the middle layer may be an aluminum metal layer.
  • the inner layer For the PP layer the packaging bag 120 is used to accommodate the battery core 100, and one side of the packaging part 121 in the packaging bag 120 is cut according to the section line CC or DD shown in FIG. In the cross-sectional view, the shape of the recess 160 is U-shaped.
  • the length L1 of the sealing area is 10 mm
  • the length L2 of the second sealing section 1213 is 7 mm
  • L1/L2 1.4.
  • the maximum thickness T1 of the first sealing section 1212 is 0.45 mm
  • the thickness T2 of the second sealing section 1213 is 0.25 mm.
  • the longitudinal cross-sectional area N of the first sealing section 1212 is 0.38 mm 2
  • the longitudinal cross-sectional area K of the second sealing section 1213 is 1.61 mm 2 .
  • One side sealing part 121 of the packaging bag 120 obtained in Example 1 was cut and cut into splines with a width of 8 mm, and a tensile test was performed in a universal material testing machine to obtain a tensile curve as shown in FIG. 14. It can be seen from FIG. 14 that the maximum value of the tensile curve is 73N.
  • the aluminum plastic film breaks when the spline is stretched, and the first bonding layer 141 (PP layer) and the second bonding layer 151 (PP layer) are formed. The sealed area is not pulled apart.
  • One side sealing part 121 of the packaging bag 120 obtained in Example 2 was cut and cut into splines with a width of 8 mm, and a tensile test was performed in a universal material testing machine to obtain a tensile curve as shown in FIG. 15. It can be seen from FIG. 15 that the maximum value of the tensile force curve is 69N, the aluminum plastic film is broken when the spline is stretched, and the first bonding layer 141 (PP layer) and the second bonding layer 151 (PP layer) are formed The sealed area is not pulled apart.
  • Embodiment 1 After one side of the packaging part 121 in the packaging bag 120 is cut according to the section line CC or DD shown in FIG. 1, a sectional view shown in FIG. 16 is obtained.
  • the shape is U-shaped.
  • the length L1 of the first sealing section 1212 is 1.5 mm
  • the length L3 of the third sealing section 1214 is 4.5 mm.
  • the maximum thickness T1 of the first sealing section 1212 is 0.39 mm
  • the maximum thickness of the third sealing section 1214 is max( T3)
  • the minimum thickness of the third sealing section 1214 is min(T3)
  • One side sealing part 121 of the packaging bag 120 obtained in Example 3 was cut and cut into splines with a width of 8 mm, and a tensile test was performed in a universal material testing machine to obtain a tensile curve as shown in FIG. 17.
  • the maximum peak value of the tensile curve is 89.6N, which corresponds to the strength of the third sealing section L3 (ie, the glue spill area).
  • the glue spill area is first A certain amount of elastic deformation is found, as shown in stage a shown in FIG.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Sealing Battery Cases Or Jackets (AREA)

Abstract

本申请公开了一种电芯及电池，该电芯包括电芯本体和收容电芯本体的包装袋，包装袋包括封装部，封装部包括密封区域，密封区域包括凹陷部，凹陷部设置在密封区域靠近电芯本体的端面上，凹陷部向远离电芯本体的方向凹进。根据本申请的电芯，通过在密封区域的靠近电芯本体的端面上设置凹陷部，由此可以改善封装部的溢胶区域的形貌，还可以减少封装部的电解液残留量，防止在电芯长期使用中电解液从内部破坏封装部，能够大幅度提升电芯的封装强度，进而改善电芯的封装可靠性和安全性问题，且封装工艺比较简单。

Description

电芯及电池 技术领域
本申请涉及电化学装置技术领域，具体而言，尤其涉及一种电芯及电池。
背景技术
锂离子电池因其具有高能量密度、长循环寿命、高性能价格比等优点，已被广泛应用于各种数码产品、电动工具、无人机、储能系统以及汽车动力系统中。
由于作为包装材料的铝塑复合膜本身特性，软包锂离子电池的封装可靠性一直受到各研究者的重视。特别是运用于储能系统的软包锂离子电池，对封装的长期可靠性具有更加严苛的要求。目前广泛采用的封头(如平封头或斜封头)及其封装技术对锂离子电池进行封装，所得到的锂离子电池的封装部的封装强度较低，抗蠕变性能较差，其寿命较低(一般小于三年)，无法满足锂离子电池对封装长期可靠性的要求，限制了锂离子电池在长期储能领域和对安全可靠性有较高要求的领域的应用，而且倾斜封头还带来了加工问题和磨损问题。而封装工序是软包锂离子电池生产制造过程中的关键工序，尤其是侧封和真空封装工序，对电池的安全性和可靠性至关重要。因此需要开发一种能够满足封装长期可靠性要求的封装技术。
发明内容
本申请旨在至少解决现有技术中存在的技术问题之一。为此，本申请的一个方面在于提出一种电芯，所述电芯具有较好的封装可靠性和较高的安全性。
根据本申请实施例的电芯，电芯包括电芯本体和收容所述电芯本体的包装袋，所述包装袋包括封装部，所述封装部包括密封区域，所述密封区域包括凹陷部，所述凹陷部设置在所述密封区域靠近所述电芯本体的端面上，所述凹陷部向远离所述电芯本体的方向凹进。
根据本申请实施例的电芯，通过在密封区域的靠近电芯本体的端面上设置凹陷部，能够消除温度梯度带来的热应力，消除封头直角对包装袋造成的机械应力，消除电芯本体造成的机械应力，由此可以改善封装部的溢胶区域的形貌，改善该溢胶区域的结构缺 陷，还可以减少封装部的电解液残留量，防止在电芯长期使用中电解液从内部破坏封装部，从而可以大幅度提升电芯的封装部的封装强度，进而改善电芯的封装可靠性和安全性问题。另外，在对该封装部进行拉力测试时，发现该凹陷部可以转移采用传统的封头及其封装技术得到的电芯的封装部的受力点，可以承受更大的拉力，也验证了本申请通过在封装部设置该凹陷部可以提升电芯的封装部的封装强度，进而可以改善电芯的封装可靠性和安全性问题。
在一些实施例中，所述包装袋包括第一壳体和第二壳体，所述第一壳体包括第一结合层，所述第二壳体包括第二结合层，所述第一结合层与所述第二结合层相结合形成所述密封区域和收容所述电芯本体的容纳空间，所述凹陷部与所述容纳空间连接，且所述凹陷部向远离所述容纳空间的方向凹进。
在一些实施例中，所述密封区域包括：第一密封段和第二密封段，所述第一密封段的一端与所述第二密封段连接，所述第一密封段的另一端的端面向所述第二密封段的方向凹进以形成所述凹陷部。
在一些实施例中，在沿着靠近所述容纳空间的方向上，所述密封区域的长度为L1，所述第二密封段的长度为L2，L1/L2大于等于1.2:1，且小于等于10:1。
在一些实施例中，所述第一密封段的最大厚度为T1，所述第二密封段的厚度为T2，T1/T2大于等于1.5:1，且小于等于4:1。
在一些实施例中，所述第一密封段的纵截面积为N，所述第二密封段的纵截面积为K，N/K大于0。
在一些实施例中，在沿着靠近所述容纳空间的方向上，所述第一密封段的厚度先逐渐增大，再逐渐减小。
在一些实施例中，所述凹陷部与所述容纳空间之间的接触面的至少部分为平滑的表面。
在一些实施例中，所述凹陷部与所述容纳空间之间的接触面的至少部分为弧形表面。
在一些实施例中，所述凹陷部的底部包括突起，所述突起向所述容纳空间凸出。
在一些实施例中，所述密封区域还包括第三密封段，所述第三密封段设置在所述第一密封段与所述第二密封段之间，在沿着所述容纳空间的延伸方向上，所述第三密封段的厚度逐渐增大。
在一些实施例中，在沿着靠近所述容纳空间的方向上，所述第二密封段的长度为L2，所述第三密封段的长度为L3，L2/L3大于0。
本申请的另一方面在于提出一种电池，所述电池具有较好的封装可靠性和较高的安全性。
根据本申请实施例的电池，该电池包括电芯和收容所述电芯的外壳，所述电芯包括电芯本体和收容所述电芯本体的包装袋，所述包装袋包括封装部，所述封装部包括密封区域，其特征在于，所述密封区域包括凹陷部，所述凹陷部设置在所述密封区域靠近所述电芯本体的端面上，所述凹陷部向远离所述电芯本体的方向凹进。
根据本申请实施例的电池，通过在密封区域的靠近电芯本体的端面上设置凹陷部，可以改善封装部的溢胶区域的形貌，改善该溢胶区域的结构缺陷，还可以减少封装部的电解液残留量，从而可以大幅度提升电芯的封装部的封装强度，进而改善电芯的封装可靠性和安全性问题。
附图说明
本申请的上述和/或附加的方面和优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1示出了根据本申请一实施例的电芯的结构示意图；
图2示出了图1中密封区域A处的局部放大示意图；
图3示出了图1中密封区域沿剖面线B-B方向的剖视图；
图4示出了图1中密封区域沿剖面线C-C或D-D方向的剖视图；
图5示出了图4中的铝塑膜外层(PA或PET)的拉伸应力-应变曲线；
图6示出了图4中的铝塑膜中层(Al)的拉伸应力-应变曲线；
图7示出了图4中的铝塑膜内层(PP)的拉伸应力-应变曲线；
图8示出了采用传统的平封头得到的电芯的密封区域的拉伸应力-应变曲线；
图9示出了采用本申请的封装技术得到的电芯的密封区域的拉伸应力-应变曲线，该密封区域采用沿着如图1所示的剖面线C-C或D-D方向剖开得到；
图10示出了根据本申请另一实施例的电芯的密封区域的局部剖视图，该剖视图是采用沿着如图1所示的剖面线C-C或D-D方向剖开该密封区域得到；
图11示出了图10中的局部结构的放大示意图；
图12示出了图10中密封区域的拉伸应力-应变曲线；
图13示出了根据本申请另一实施例的电芯的密封区域的局部剖视图，该剖视图是采用沿着如图1所示的剖面线C-C或D-D方向剖开该密封区域得到；
图14示出了本申请实施例一的密封区域的拉伸应力-应变曲线；
图15示出了本申请实施例二的密封区域的拉伸应力-应变曲线；
图16示出了本申请实施例三的电芯的密封区域的局部剖视图，该剖视图是采用沿着如图1所示的剖面线C-C或D-D方向剖开该密封区域得到；
图17示出了图16中密封区域的拉伸应力-应变曲线。
附图标记：
电芯110，电芯本体111，极耳112，
包装袋120，
封装部121，第一密封段1212，第二密封段1213，第三密封段1214，
容纳空间130，
第一壳体140，第一结合层141，第一金属层142，第一保护层143，
第二壳体150，第二结合层151，第二金属层152，第二保护层153，
凹陷部160，突起161。
具体实施方式
下面详细描述本申请的实施例，所述实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。
下面参考图1-图17描述根据本申请实施例的电芯110及电池。
如图1和图2所示，根据本申请实施例的电芯110包括电芯本体111和收容电芯本体111的包装袋120。电芯110可以包括与电芯本体111电连接的极耳112，极耳112从该封装袋120穿出。
具体而言，包装袋120可以包括封装部121，封装部121可以包括密封区域，如图3和图4所示，密封区域可以包括凹陷部160，凹陷部160设置在密封区域靠近电芯本体111的端面上，凹陷部160向远离电芯本体111的方向凹进。这里，凹陷部160的凹入方向，可以理解为密封区域的部分表面朝向其自身内部凹入，以形成凹陷部160。
根据本申请实施例的电芯110，通过在密封区域的靠近电芯本体111的端面上设置凹陷部160，且使凹陷部160向远离电芯本体111的方向凹进，能够消除温度梯度带来的热应力，消除封头直角对包装袋120造成的机械应力，消除电芯本体111造成的机械应力，由此可以改善封装部121的溢胶区域的形貌，改善该溢胶区域的结构缺陷，还可以减少封装部121的电解液残留量，防止在电芯110长期使用中电解液从内部破坏封装 部121，从而可以大幅度提升电芯110的封装部121的封装强度，进而改善电芯110的封装可靠性和安全性问题。另外，在对该封装部121进行拉力测试时，发现该凹陷部160可以转移该封装部121的受力点，可以承受更大的拉力，也验证了本申请通过在封装部121设置该凹陷部160可以提升电芯110的封装部121的封装强度，进而可以改善电芯110的封装可靠性和安全性问题。
如图3所示，根据申请的一些实施例，包装袋120可以包括第一壳体140和第二壳体150。其中，第一壳体140包括第一结合层141，第二壳体150包括第二结合层151，第一结合层141与第二结合层151相结合形成密封区域和收容电芯本体111的容纳空间130，凹陷部160与容纳空间130连接，且凹陷部160向远离容纳空间130的方向凹进。通过此设置方式，可以提升封装部121的结构稳定性，便于电芯110的封装，同时也有利于在第一结合层141和第二结合层151之间构造出密封区域，进而构造出容纳空间130。
在一些实施例中，如图3和图4所示，第一壳体140还可以包括第一金属层142和第一保护层143，第一金属层142设置在第一结合层141和第一保护层143之间。同样的，第二壳体150也可以包括第二金属层152和第二保护层153，第二金属层152设置在第二结合层151和第二保护层153之间。其中，第一保护层143和/或第二保护层153的材质可以是聚酰胺(PA)、聚对苯二甲酸乙二醇酯(PET)或其组合等，第一金属层142和/或第二金属层152的材质可以是铝或钢等，第一结合层141和/或第二结合层151的材质可以是聚丙烯(PP)、聚乙烯(PE)、聚萘二甲酸乙二醇酯(PEN)或其组合等。
在一些实施例中，如图3、图4所示，密封区域可以包括第一密封段1212和第二密封段1213。其中，第一密封段1212的一端与第二密封段1213连接，第一密封段1212的另一端的端面向第二密封段1213的方向凹进以形成凹陷部160。可以理解的是，密封区域可以通过本申请设计的封头对第一结合层141和第二结合层151进行热压而形成，第一结合层141和第二结合层151在受热熔化后，受压时可向压力较小的范围流动以形成溢胶区域，该溢胶区域包括第一密封段1212。本申请通过改善溢胶区域的形貌，使得第一密封段在与容纳空间相连接的界面上形成有凹陷部160，可以改善该溢胶区域的结构缺陷，可以转移采用传统的封头及其封装技术得到的电芯110的封装部121的受力点，进而可以改变封装部121的受力方式，从而可以承受更大的拉力和大幅度提升电芯110的封装部121的封装强度，改善电芯110及其电池的封装可靠性和安全性问题。
根据本申请的一些实施例，如图4所示，在沿着靠近容纳空间130的第一方向上， 例如沿着图4中所示的b到a的方向，密封区域(包括第一密封段和第二密封段)的长度为L1，即从本申请的封头在a-b方向上两端的宽度，第二密封段1213的长度为L2，即从封装部121凸起出现的位置到该凸起消失的位置之间的长度，L1/L2大于等于1.2，且小于等于10。在一些实施例中，L1/L2大于等于1.5，且小于等于3，此时封装部121具有更高的封装强度。需要说明的是，该凸起出现的位置和消失的位置可以从电芯110的封装部121的表面外观上清晰的看到，或者说这两个位置可以通过本申请的封头在电芯110的封装部121上留下的。
根据本申请的一些实施例，如图4所示，在沿着与第一方向大致垂直的第二方向上，第一密封段1212的最大厚度为T1，第二密封段1213的厚度为T2，T1/T2大于等于1.5，且小于等于4。在一些实施例中，T1/T2大于等于1.5，且小于等于2.5，此时封装部121具有更高的封装强度。
在一些实施例中，如图4所示，在沿着第二方向上，第一密封段1212的纵截面积为N，第二密封段1213的纵截面积为K，N/K大于0，且小于等于100。在一些实施例中，N/K大于等于0.1，且小于等于50。在一些实施例中，N/K大于等于0.1，且小于等于1。需要说明的是，各截面积采用如下方法进行测量：将图1沿着剖面线C-C或D-D剖开，得到封装部121的剖面形貌，再采用基恩仕5000(VHX-5000)显微镜的面积测量功能对N和K进行测量。
接下来，以包装袋为铝塑膜为例，对采用该包装袋得到的封装部的密封区域的失效模式进行研究。包装袋包括上铝塑膜(第一壳体)和下铝塑膜(第二壳体)，采用热压工艺将上铝塑膜和下铝塑膜压合形成容纳空间和封装部的密封区域。上铝塑膜和下铝塑膜分别包括外层、中层和内层，外层(第一保护层143或第二保护层153)的材质为PET或PA，中层(第一金属层142或第二金属层152)的材质为Al，内层(第一结合层141或第二结合层151)的材质为PP。对铝塑膜的外层、中层、内层、采用传统的封头制得的密封区域和采用本申请的封装技术得到的密封区域分别进行拉力测试，得到拉伸应力-应变曲线，即拉力曲线，如图5至图9所示。需要说明的是，拉力曲线可通过如下的方法测得：将样条夹在万能材料试验机(深圳三思纵横科技股份有限公司，型号UTM6101)的夹具上，以30mm/min的速度进行拉伸，得到拉伸应力-应变曲线。其中，密封区域的样条可通过如下方法制得：以图1为例，将图1中的密封区域沿着剖面线C-C或者D-D剪开并裁切(可通过剪刀、刀片、刀模等)成具有8mm宽度的样条(宽度是指样条在与剖面线C-C或者D-D垂直的方向上两端的距离)；铝塑膜的外层、中 层和内层的样条按与上述密封区域的同样的规格制得。
从图8可知，采用传统的封头得到的密封区域的拉力曲线包括L阶段和N1阶段，在L阶段时，铝塑膜上PA或PET、Al、PP以及溢胶区域的PP均发生轻微的拉伸；当拉伸进行到一定程度后(最大值)溢胶区域的PP发生塑性变形进入N1阶段(出现PP-PP/PP-Al分层，判定失效)，此时PA或PET、Al、PP均不再发生拉伸，拉力由溢胶区域的PP通过其延展性提供，强度很低。而从图9可知采用本申请的封装技术得到的密封区域的拉力曲线包括L阶段、M阶段和N2阶段，在L阶段时，铝塑膜上PA或PET、Al、PP均发生轻微的拉伸，而溢胶区域的PP发生轻微拉伸或者可能不会出现变形；在M阶段时，铝塑膜上PA或PET、Al、PP均发生严重的塑性拉伸，而溢胶区域的PP发生轻微的拉伸，由于PA或PET、PP的韧性比Al好，因此该阶段的曲线和Al的拉伸曲线一样；当Al拉断后，拉力曲线迅速(垂直地)衰减，进入N2阶段；N2阶段与N1阶段不同的是，N2阶段的拉力由铝塑膜上Al断裂处的PP、PET或PA提供，失效模式由N1阶段的PP-PP(上铝塑膜的PP与下铝塑膜的PP的结合层)分层或者PP-Al分层变为N2阶段的铝塑膜拉断。
根据本申请的一些实施例，如图4或图10所示，凹陷部160与容纳空间130之间的接触面的至少部分为平滑的表面。由此可以避免在接触面的位置处产生应力集中，可以进一步的提升封装部121所能承受的拉力值，从而能够进一步的增大封装部121的封装强度。需要说明的是，接触面的形状并不限于此，只要其可以起到增强封装部121的强度即可，例如，在一些实施例中，凹陷部160与容纳空间130之间的接触面的至少部分为弧形表面。需要说明的是，对凹陷部160内壁面的形状，这里不做特殊要求，只要凹陷部160的中部具有向第一密封段1212的内部凹陷的形状即可，例如，在一些实施例中，凹陷部160可以呈圆滑的V形、U形或口袋形等，本申请不以此为限。
在一些实施例中，如图4或图10所示，在沿着靠近容纳空间130的方向上，如图4所示的从b到a的方向上，第一密封段1212的厚度先逐渐增大，再逐渐减小。如图10所示的从b到a的方向上，第一密封段1212的厚度先逐渐增大，当其厚度增大到最大时，第一密封段1212的厚度又开始逐渐减小。
在一些实施例中，如图10所示，凹陷部160的底部包括突起161，突起161向容纳空间130凸出，此时凹陷部160的底部形状呈微小的M形。在对具有突起161的凹陷部160进行拉力测试时，得到的拉伸应力-应变曲线如图12所示，由图12可知，第一密封段的受力点仍在凹陷部的底部，仍然可以起到增强封装部121的封装强度。
如图13所示，根据本申请的一些实施例，密封区域还可以包括第三密封段1214。其中，第三密封段1214设置在第一密封段1212与第二密封段1213之间，在沿着靠近容纳空间130的方向上(如图13中的b到a方向)，第三密封段1214的厚度逐渐增大。具体的，在沿着靠近容纳空间130的方向上，第二密封段1213的长度为L2，第三密封段1214的长度为L3，即从密封区域的厚度开始逐渐变大的位置到凸起出现的位置之间的长度，则L2/L3大于等于0。当L2越小时，该密封区域抵抗工序波动的能力越强，当L3越小时，该密封区域抗磨损的能力越强。在一些实施例中，L2/L3大于等于0.5，且小于等于2。
如图13所示，在沿着靠近容纳空间124的第一方向上，设第三密封段1214的倾斜角为α，第三密封段1214的长度为L3。在第二方向上，第三密封段1214的最大厚度为max(T1)，第三密封段1214的最小厚度为min(T1)，则max(T1)＝min(T1)+L3·tanα，其中，0°≤α≤2°。在一些实施例中，第一密封段1212的最大厚度与第三密封段1214的最小厚度可以相等，即max(T1)＝min(T3)。
此外，本申请还公开了根据上述电芯所得到的电池，该电池包括电芯110和收容电芯110的外壳，电芯110包括电芯本体111和收容电芯本体111的包装袋120，包装袋120包括封装部121，封装部121包括密封区域，密封区域包括凹陷部160，凹陷部160设置在密封区域靠近电芯本体111的端面上，凹陷部160向远离电芯本体111的方向凹进。
下面参照附图以具体的实施例详细描述根据本申请实施例的电芯110。应该理解的是，下述描述仅是示例性说明，而不是对本申请的限制。
实施例1
在该实施例中，封装袋120为铝塑膜，铝塑膜包括外层、中层和内层，外层为PA、PET或者两者的复合材料制成，中层可以为铝金属层，内层为PP层，该封装袋120用于收容电芯100，将该封装袋120中的一侧封装部121按如图1所示的剖面线C-C或D-D剖开后，得到如图4所示的剖面图，凹陷部160的形状呈U形。
如图4所示，在沿着靠近容纳空间130的第一方向上(从b到a的方向)，密封区域的长度L1为10mm，第二密封段1213的长度L2为7mm，L1/L2＝1.4。如图4中所示，在第二方向上，第一密封段1212的最大厚度T1为0.45mm，第二密封段1213的厚度T2为0.25mm。第一密封段1212的纵截面积N为0.38mm 2，第二密封段1213的纵截面积K为1.61mm 2。
将实施例1所得到的封装袋120的一侧封装部121剪开并裁切成具有8mm宽度的样条，在万能材料试验机进行拉力测试，得到如图14所示的拉力曲线。从图14可以看出，该拉力曲线的最大值为73N，该样条在拉伸时铝塑膜破裂，而第一结合层141(PP层)与第二结合层151(PP层)所形成的密封区域未被拉开。
实施例2
与实施例1不同的是，凹陷部160的形状呈V形，L1＝5mm，L2＝2mm；T1＝0.39mm，T2＝0.18mm；K＝0.36mm 2，N＝0.31mm 2。
将实施例2所得到的封装袋120的一侧封装部121剪开并裁切成具有8mm宽度的样条，在万能材料试验机进行拉力测试，得到如图15所示的拉力曲线。从图15可以看出，该拉力曲线的最大值为69N，该样条在拉伸时铝塑膜破裂，而第一结合层141(PP层)与第二结合层151(PP层)所形成的密封区域未被拉开。
实施例3
与实施例1不同的是，将该封装袋120中的一侧封装部121按如图1所示的剖面线C-C或D-D剖开后，得到如图16所示的剖面图，凹陷部160的形状呈U形。在该实施例中，在如图15所示的从b到a的第一方向上，第一密封段1212的长度L1为1.5mm，第三密封段1214的长度L3为4.5mm。在第二方向上，第一密封段1212的最大厚度T1为0.39mm，第三密封段1214的厚度逐渐增大，其倾斜角为α＝0.5°，第三密封段1214的最大厚度为max(T3)，第三密封段1214的最小厚度为min(T3)，则max(T3)＝min(T3)+L3·tanα＝0.28mm。
将实施例3所得到的封装袋120的一侧封装部121剪开并裁切成具有8mm宽度的样条，在万能材料试验机进行拉力测试，得到如图17所示的拉力曲线。从图17可以看出，基于该方案封装后，该拉力曲线的最大峰值为89.6N，对应于第三密封段L3(即溢胶区域)的强度，该样条在拉伸时溢胶区域首先发现一定的弹性变形，如图17所示的a阶段，随后由于溢胶区域的强度过高，将同时发生溢胶区域的PP层的塑性变形和铝塑膜的拉伸，即图17中的b阶段；由于本实施例选用的铝塑膜强度较高，溢胶区域的PP层的抗拉强度未超过铝塑膜本身的抗拉强度，故铝塑膜在发生颈缩后溢胶区域的PP层被拉断，后续拉伸应力-应变曲线如图17中所示的c阶段。
在本申请的描述中，需要理解的是，术语“长度”、“宽度”、“厚度”、“上”、“下”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的 方位构造和操作，因此不能理解为对本申请的限制。在本申请的描述中，“多个”的含义是两个或两个以上。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示意性实施例”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本申请的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不一定指的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任何的一个或多个实施例或示例中以合适的方式结合。
尽管已经示出和描述了本申请的实施例，本领域的普通技术人员可以理解：在不脱离本申请的原理和宗旨的情况下可以对这些实施例进行多种变化、修改、替换和变型，本申请的范围由权利要求及其等同物限定。

Claims (13)

  1. 一种电芯，包括电芯本体和收容所述电芯本体的包装袋，所述包装袋包括封装部，所述封装部包括密封区域，其特征在于，所述密封区域包括凹陷部，所述凹陷部设置在所述密封区域靠近所述电芯本体的端面上，所述凹陷部向远离所述电芯本体的方向凹进。
  2. 根据权利要求1所述的电芯，其特征在于，所述包装袋包括第一壳体和第二壳体，所述第一壳体包括第一结合层，所述第二壳体包括第二结合层，所述第一结合层与所述第二结合层相结合形成所述密封区域和收容所述电芯本体的容纳空间，所述凹陷部与所述容纳空间连接，且所述凹陷部向远离所述容纳空间的方向凹进。
  3. 根据权利要求2所述的电芯，其特征在于，所述密封区域包括：
    第一密封段；及
    第二密封段，所述第一密封段的一端与所述第二密封段连接，所述第一密封段的另一端的端面向所述第二密封段的方向凹进以形成所述凹陷部。
  4. 根据权利要求3所述的电芯，其特征在于，在沿着靠近所述容纳空间的方向上，所述密封区域的长度为L1，所述第二密封段的长度为L2，L1/L2大于等于1.2:1，且小于等于10:1。
  5. 根据权利要求3所述的电芯，其特征在于，所述第一密封段的最大厚度为T1，所述第二密封段的厚度为T2，T1/T2大于等于1.5:1，且小于等于4:1。
  6. 根据权利要求3所述的电芯，其中，所述第一密封段的纵截面积为N，所述第二密封段的纵截面积为K，N/K大于0。
  7. 根据权利要求3所述的电芯，其特征在于，在沿着靠近所述容纳空间的方向上，所述第一密封段的厚度先逐渐增大，再逐渐减小。
  8. 根据权利要求3所述的电芯，其特征在于，所述凹陷部与所述容纳空间之间的接触面的至少部分为平滑的表面。
  9. 根据权利要求3所述的电芯，其特征在于，所述凹陷部与所述容纳空间之间的接触面的至少部分为弧形表面。
  10. 根据权利要求3所述的电芯，其特征在于，所述凹陷部的底部包括突起，所述突起向所述容纳空间凸出。
  11. 根据权利要求3所述的电芯，其特征在于，所述密封区域还包括第三密封段， 所述第三密封段设置在所述第一密封段与所述第二密封段之间，在沿着所述容纳空间的延伸方向上，所述第三密封段的厚度逐渐增大。
  12. 根据权利要求11所述的电芯，其特征在于，在沿着靠近所述容纳空间的方向上，所述第二密封段的长度为L2，所述第三密封段的长度为L3，L2/L3大于0。
  13. 一种电池，包括电芯和收容所述电芯的外壳，所述电芯包括电芯本体和收容所述电芯本体的包装袋，所述包装袋包括封装部，所述封装部包括密封区域，其特征在于，所述密封区域包括凹陷部，所述凹陷部设置在所述密封区域靠近所述电芯本体的端面上，所述凹陷部向远离所述电芯本体的方向凹进。
PCT/CN2019/126424 2018-12-18 2019-12-18 电芯及电池 WO2020125696A1 (zh)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201811547628.8 2018-12-18
CN201811547628.8A CN111341946B (zh) 2018-12-18 2018-12-18 电芯及电池
US16/430,048 US11342616B2 (en) 2018-12-18 2019-06-03 Cell and battery
US16/430,048 2019-06-03

Publications (1)

Publication Number Publication Date
WO2020125696A1 true WO2020125696A1 (zh) 2020-06-25

Family

ID=71072978

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/126424 WO2020125696A1 (zh) 2018-12-18 2019-12-18 电芯及电池

Country Status (3)

Country Link
US (1) US11342616B2 (zh)
CN (1) CN111341946B (zh)
WO (1) WO2020125696A1 (zh)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112542639B (zh) * 2020-12-08 2023-07-18 珠海冠宇电池股份有限公司 软包电池及其制备方法
CN112599894A (zh) * 2020-12-11 2021-04-02 珠海冠宇电池股份有限公司 软包电池及其制备方法
CN113097610B (zh) * 2021-03-31 2023-02-24 东莞新能安科技有限公司 电化学装置模组和电子装置
WO2022261833A1 (zh) * 2021-06-15 2022-12-22 宁德新能源科技有限公司 电化学装置及用电设备
CN114597474A (zh) * 2022-03-21 2022-06-07 珠海冠宇电池股份有限公司 一种电池
CN114614174A (zh) * 2022-03-29 2022-06-10 东莞新能安科技有限公司 电池壳、电池及电子装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1189924A (zh) * 1996-04-23 1998-08-05 住友电气工业株式会社 非水电解质电池
JP2000173562A (ja) * 1998-12-01 2000-06-23 Tokai Rubber Ind Ltd 薄型電池用袋体のシール方法およびそれに用いる金型
CN201638865U (zh) * 2010-04-01 2010-11-17 宁德新能源科技有限公司 电池封装箔
CN208045554U (zh) * 2018-04-10 2018-11-02 宁德新能源科技有限公司 电池

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4433506B2 (ja) * 1998-11-06 2010-03-17 株式会社ジーエス・ユアサコーポレーション 電池
JP4830267B2 (ja) * 2004-05-21 2011-12-07 トヨタ自動車株式会社 ラミネート電池
JP5463212B2 (ja) * 2010-06-10 2014-04-09 日立マクセル株式会社 ラミネート形電池およびその製造方法
WO2012162813A1 (en) * 2011-06-01 2012-12-06 Magna E-Car Systems Limited Partnership Pouch-type battery cell
KR20130085719A (ko) * 2012-01-20 2013-07-30 에스케이이노베이션 주식회사 파우치형 전지의 실링 장치 및 실링 방법
JP2013196788A (ja) * 2012-03-15 2013-09-30 Denso Corp 非水電解液二次電池
JP2014032924A (ja) * 2012-08-06 2014-02-20 Nec Energy Devices Ltd フィルム外装電池およびその製造方法
KR101465172B1 (ko) * 2012-12-24 2014-11-25 주식회사 엘지화학 내구성 향상을 위해 실링 마진을 가진 파우치형 이차 전지
KR102042018B1 (ko) * 2014-02-27 2019-11-07 주식회사 엘지화학 실링 라인이 형성되어 있는 외주면 실링부를 포함하는 전지셀, 및 이를 생산하기 위한 전지셀 실링장치
CN107293652B (zh) * 2016-04-11 2020-10-02 宁德新能源科技有限公司 包装封印结构及其制备方法及软包装电池
CN106058083A (zh) * 2016-08-19 2016-10-26 宁德时代新能源科技股份有限公司 软包电池外壳及软包电池
US10727453B2 (en) * 2016-09-28 2020-07-28 Lg Chem, Ltd. Method for sealing pouch casing of secondary battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1189924A (zh) * 1996-04-23 1998-08-05 住友电气工业株式会社 非水电解质电池
JP2000173562A (ja) * 1998-12-01 2000-06-23 Tokai Rubber Ind Ltd 薄型電池用袋体のシール方法およびそれに用いる金型
CN201638865U (zh) * 2010-04-01 2010-11-17 宁德新能源科技有限公司 电池封装箔
CN208045554U (zh) * 2018-04-10 2018-11-02 宁德新能源科技有限公司 电池

Also Published As

Publication number Publication date
CN111341946A (zh) 2020-06-26
US20200194743A1 (en) 2020-06-18
US11342616B2 (en) 2022-05-24
CN111341946B (zh) 2022-05-17

Similar Documents

Publication Publication Date Title
WO2020125696A1 (zh) 电芯及电池
US10510997B2 (en) Film-covered battery
CN106299182B (zh) 一种具有定位防爆功能的软包锂离子电池及其制造方法
JPH10208708A (ja) 扁平形電池
JP6128497B2 (ja) ラミネート電池及びその製造方法
EP4231403A2 (en) Secondary battery
CN211045483U (zh) 软包电池及电池模组
US20190074550A1 (en) Electrode assembly for secondary battery and method for producing electrode assembly for secondary battery
WO2020125695A1 (zh) 电芯及电池
WO2010072156A1 (zh) 一种电池及制造方法
WO2010124589A1 (zh) 一种电池及其制造方法
CN209045702U (zh) 一种电芯以及封装装置
JP2005353503A (ja) 薄型電気化学セル
JP2014232592A (ja) ラミネート二次電池及びその製造方法
CN113659258A (zh) 一种用于Degas封装的上封头、下封头及用其提高Degas封装可靠性的方法
CN217306619U (zh) 一种软包电池电芯封装结构
CN218004973U (zh) 一种电池及封装封头
CN214957040U (zh) 一种软包锂离子电池
CN215184233U (zh) 一种钢壳扣式电池
CN216928870U (zh) 一种电池极耳结构及软包扣式电池
CN220628116U (zh) 防爆阀及盖板结构
CN219534685U (zh) 耐高温型铅酸蓄电池槽盖
CN219350322U (zh) 一种保护膜及电池
CN218039504U (zh) 一种电池封头以及软包电池
CN220627964U (zh) 一种电池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19898438

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19898438

Country of ref document: EP

Kind code of ref document: A1