WO2022141161A1 - 电极组件和电化学装置 - Google Patents

电极组件和电化学装置 Download PDF

Info

Publication number
WO2022141161A1
WO2022141161A1 PCT/CN2020/141276 CN2020141276W WO2022141161A1 WO 2022141161 A1 WO2022141161 A1 WO 2022141161A1 CN 2020141276 W CN2020141276 W CN 2020141276W WO 2022141161 A1 WO2022141161 A1 WO 2022141161A1
Authority
WO
WIPO (PCT)
Prior art keywords
groove
positive electrode
electrode assembly
positive
current collector
Prior art date
Application number
PCT/CN2020/141276
Other languages
English (en)
French (fr)
Inventor
吴华
赵义
彭业军
郭培培
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
Priority to CN202080030181.6A priority Critical patent/CN113826240B/zh
Priority to JP2023521134A priority patent/JP2023546000A/ja
Priority to EP20967506.5A priority patent/EP4254538A1/en
Priority to KR1020237013142A priority patent/KR20230061553A/ko
Priority to PCT/CN2020/141276 priority patent/WO2022141161A1/zh
Publication of WO2022141161A1 publication Critical patent/WO2022141161A1/zh
Priority to US18/215,906 priority patent/US20230344019A1/en

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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
    • H01M50/474—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by their position inside the cells
    • 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
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • 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
    • H01M50/531—Electrode connections inside a battery casing
    • 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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • 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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • 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

  • the present application relates to the field of batteries, and in particular, to an electrode assembly and an electrochemical device having the electrode assembly.
  • Lithium-ion batteries are now widely used in convenient application scenarios such as consumer electronics and power tools, and batteries with fast-charging designs are accounting for more and more market applications.
  • a cell structure with lower internal resistance is required.
  • a structure with a slot in the middle of the pole piece is developed and applied, so that the pole lug is centered and welded in the middle of the pole piece.
  • This structure can significantly reduce the internal resistance of the cell and improve the charging and discharging speed.
  • there is a large thickness difference locally at the groove position which makes the surface consistency of the pole piece worse, resulting in undervoltage in some areas of the cell and the formation process.
  • the problem of lithium precipitation is prone to thermal runaway caused by internal short circuit.
  • the present application provides an electrode assembly and an electrochemical device having the electrode assembly.
  • the thickness consistency between the groove and the electrode body region is ensured, and the electrode lug position is improved. reduce the risk of lithium precipitation problems.
  • Embodiments of the present application provide an electrode assembly including a positive electrode sheet, a negative electrode sheet, a separator, and a positive electrode tab.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on the surface of the positive electrode current collector.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector.
  • the separator is arranged between the positive electrode sheet and the negative electrode sheet.
  • the positive electrode tab is electrically connected to the positive electrode current collector.
  • the positive electrode active material layer is provided with a first groove, one end of the positive electrode tab is arranged in the first groove, and is electrically connected to the positive electrode current collector.
  • the negative electrode active material layer is provided with a second groove, the second groove corresponds to the first groove, and the second groove extends to the negative electrode current collector along the thickness direction of the electrode assembly , the second groove is provided with a first protective glue.
  • the thickness of the first protective glue is less than or equal to the depth of the second groove.
  • the positive electrode sheet includes a first end and a second end disposed opposite to each other, and in a direction extending from the first end to the second end, the width of the positive electrode tab is smaller than that of the second end The width of the groove.
  • the peripheral side of the first protective glue contacts the negative electrode active material layer.
  • the positive electrode sheet, the separator and the negative electrode sheet are wound in sequence.
  • a first insulating member is provided on the positive electrode sheet, and the first insulating member covers the first groove.
  • the first insulating member covers part of the positive electrode active material layer.
  • a second insulating member is provided on the negative electrode sheet, and the second insulating member covers the second groove.
  • the second insulating member covers part of the negative electrode active material layer.
  • the projected area of the first insulating member is larger than the projected area of the second insulating member.
  • a second protective glue is disposed in the first groove.
  • the peripheral side of the second protective glue contacts the positive electrode active material layer.
  • the first protective glue is adhesive paper, coated adhesive layer or filled glue.
  • the width of the first protective glue is W1
  • the width of the second groove is W2
  • the width of the second insulating member is W3
  • the width of the first insulating member is W4, wherein, W1 ⁇ W2 ⁇ W3 ⁇ W4.
  • the length of the first protective glue is L1
  • the length of the second groove is L2
  • the length of the second insulating member is L3
  • the length of the first insulating member is L4, wherein, L1 ⁇ L2 ⁇ L3 ⁇ L4.
  • the thickness of the first protective glue is T1
  • the depth of the second groove is T2, where T1 ⁇ T2.
  • the dimensional relationship between the second groove and the first protective glue satisfies: 0mm ⁇ L2-L1 ⁇ 5mm, 0mm ⁇ W2-W1 ⁇ 5mm, 0 ⁇ m ⁇ T2-T1 ⁇ 20 ⁇ m.
  • the dimensional relationship between the second groove and the first protective glue satisfies: 1mm ⁇ L2-L1 ⁇ 5mm, 1mm ⁇ W2-W1 ⁇ 5mm, 0 ⁇ m ⁇ T2-T1 ⁇ 20 ⁇ m.
  • the dimensional relationship between the second groove and the second insulating member satisfies: 1 mm ⁇ L3-L2 ⁇ 5mm, and 1mm ⁇ W3-W2 ⁇ 5mm.
  • the dimensional relationship between the first insulating member and the second insulating member satisfies that 1 mm ⁇ L4-L3 ⁇ 10mm, and 1mm ⁇ W4-W3 ⁇ 10mm.
  • the dimensional relationship between the first insulating member and the second groove satisfies 1 mm ⁇ L4-L2 ⁇ 10mm, and 1mm ⁇ W4-W2 ⁇ 10mm.
  • the width of the positive electrode tab is W0
  • the dimensional relationship between the first insulating member and the second groove satisfies, 1mm ⁇ L4-L2 ⁇ 10mm, and 1mm ⁇ W4-W2 ⁇ 10mm.
  • the width of the second protective glue is the same as the width of the first groove, both W5; the length of the second protective glue is the same as the length of the first groove, both are L5, and the first groove is the same as the first groove.
  • the dimensional relationship between the two grooves satisfies: 1mm ⁇ L5-L2 ⁇ 10mm, 1mm ⁇ W5-W2 ⁇ 10mm.
  • Embodiments of the present application further provide an electrochemical device, including a packaging case and the above-mentioned electrode assembly, where the electrode assembly is accommodated in the packaging case.
  • the second groove corresponds to the first groove, and extends to the negative electrode current collector along the thickness direction of the electrode assembly, so as to reserve enough for the welding burr of the positive electrode tab space to prevent the welding burr from penetrating the second groove; even when the welding burr penetrates the second groove, the positive electrode current collector electrically connected to the positive electrode tab is in contact with the negative electrode current collector instead of the negative electrode active material layer. Prevent the most dangerous short-circuit situations from occurring.
  • FIG. 1 is a schematic diagram of the winding structure of the electrode assembly in the first embodiment.
  • FIG. 2 is a schematic diagram of a partial structure of the electrode assembly shown in FIG. 1 , wherein the separator is omitted.
  • FIG. 3 is a schematic view of the unfolded structure of the positive electrode sheet and the negative electrode sheet in the electrode assembly shown in FIG. 1 .
  • FIG. 4 is a schematic diagram of the winding structure of the electrode assembly in the second embodiment.
  • FIG. 5 is a partial structural schematic diagram of the electrode assembly shown in FIG. 4 , wherein the isolation film is omitted.
  • FIG. 6 is a schematic view of the unfolded structure of the positive electrode sheet and the negative electrode sheet in the electrode assembly shown in FIG. 4 .
  • FIG. 7 is a schematic diagram of the winding structure of the electrode assembly in the third embodiment.
  • Fig. 8 is a schematic partial structural diagram of the electrode assembly shown in Fig. 7, in which the separator is omitted.
  • FIG. 9 is a schematic view of the unfolded structure of the positive electrode sheet and the negative electrode sheet in the electrode assembly shown in FIG. 7 .
  • FIG. 10 is a schematic diagram of the winding structure of the electrode assembly in the fourth embodiment.
  • FIG. 11 is a partial structural schematic diagram of the electrode assembly shown in FIG. 10 , wherein the isolation film is omitted.
  • FIG. 12 is a schematic view of the unfolded structure of the positive electrode sheet and the negative electrode sheet in the electrode assembly shown in FIG. 10 .
  • FIG. 13 is a schematic diagram of the winding structure of the electrode assembly in the fifth embodiment.
  • FIG. 14 is a schematic diagram of a partial structure of the electrode assembly shown in FIG. 13 , wherein the separator is omitted.
  • FIG. 15 is a schematic view of the unfolded structure of the positive electrode sheet and the negative electrode sheet in the electrode assembly shown in FIG. 13 .
  • the embodiments of the present application provide an electrode assembly, including a positive electrode sheet, a negative electrode sheet, a separator, and a positive electrode tab.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on the surface of the positive electrode current collector.
  • the negative electrode sheet is stacked with the positive electrode sheet, and includes a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector.
  • the separator is arranged between the positive electrode sheet and the negative electrode sheet.
  • the positive electrode tab is electrically connected to the positive electrode current collector.
  • the positive electrode active material layer is provided with a first groove, one end of the positive electrode tab is arranged in the first groove, and is electrically connected to the positive electrode current collector.
  • the negative electrode active material layer is provided with a second groove, the second groove corresponds to the first groove, and the second groove extends to the negative electrode current collector along the thickness direction of the electrode assembly , the second groove is provided with a first protective glue.
  • the second groove corresponds to the first groove and extends to the negative electrode current collector along the thickness direction of the electrode assembly, in order to reserve enough space for the welding burr of the positive electrode tab to prevent welding.
  • the printing burr penetrates the second groove; even when the welding burr penetrates the second groove, the positive current collector electrically connected to the positive tab is in contact with the negative current collector, not the negative active material layer, preventing the most dangerous short circuit situation happens.
  • the electrode assembly 100 includes a positive electrode sheet 10 , a negative electrode sheet 20 , a separator 30 , a positive electrode tab 41 and a negative electrode tab 42 .
  • the positive electrode sheet 10 and the negative electrode sheet 20 are stacked and wound, and the separator 30 is arranged between the positive electrode sheet 10 and the negative electrode sheet 20 .
  • the positive electrode tab 41 is electrically connected to the positive electrode sheet 10
  • the negative electrode tab 42 is electrically connected to the negative electrode sheet 20 .
  • the positive electrode sheet 10 includes a positive electrode current collector 11 and a positive electrode active material layer 12 disposed on the surface of the positive electrode current collector 11 .
  • the positive electrode active material layers 12 are respectively provided on the opposite side surfaces of the positive electrode current collector 11 .
  • the positive active material layer 12 is respectively provided with a first groove 13 and a third groove 14.
  • the first groove 13 Overlapping the projection of the third groove 14 , the portion of the positive electrode current collector 11 corresponding to the first groove 13 exposes the first groove 13 and the third groove 14 .
  • One end of the positive electrode tab 41 is disposed in the first groove 13 and is electrically connected to the positive electrode current collector 11 .
  • the connection method of the positive electrode tab 41 and the positive electrode current collector 11 includes but is not limited to ultrasonic welding, thermal fusion welding, and the like.
  • the arrangement of the third groove 14 is beneficial to avoid welding failure caused by the contamination of the welding head welding seat by the positive electrode active material layer 12 during the welding process.
  • the positive current collector 11 in the first groove 13 can be recessed toward the third groove 14, so that the third groove 14 can absorb the thickness of the positive electrode tab 41 and prevent the positive electrode tab 41 from protruding from the positive electrode
  • the surface of the sheet 10 maintains the overall thickness of the electrode assembly 100 to be uniform.
  • the second groove 23 extends to the negative electrode current collector 21 along the thickness direction of the electrode assembly 100
  • the fourth groove 24 extends to the negative electrode current collector along the thickness direction of the electrode assembly 100
  • the fluid 21 is used to avoid the internal short circuit problem of the electrode assembly 100 caused by the burrs in the second groove 23 and the fourth groove 24 contacting the tabs due to lithium deposition.
  • the thickness direction of the electrode assembly 100 is the direction indicated by arrow A in FIG. 2 .
  • the second groove 23 corresponds to the first groove 13
  • the fourth groove 24 corresponds to the third groove 14
  • the second groove 23 and the fourth groove 24 are along the electrode
  • the thickness direction of the assembly 100 extends to the negative electrode current collector 21 to reserve enough space for the welding burr of the positive electrode tab 41 to prevent the welding burr from penetrating the second groove 23; even when the welding burr penetrates the second groove 23
  • the positive electrode current collector 11 electrically connected to the positive electrode tab 41 is also in contact with the negative electrode current collector 21 instead of the negative electrode active material layer 22 to prevent the occurrence of the most dangerous short circuit.
  • the second groove 23 and the fourth groove 24 are also provided with a first protective glue 50 to solve the thickness difference generated by the groove itself after removing the active substance, and ensure the thickness of the groove and the main body area of the pole piece. consistency, thereby maintaining the cycle performance consistency of the electrode assembly 100 and improving the kinetic performance of the electrode assembly 100 .
  • the first protective glue 50 includes, but is not limited to, adhesive tape or other fluid filling glue, which has insulating properties and can make up for the thickness difference at the groove.
  • the thickness of the first protective glue 50 is less than or equal to the depth of the second groove 23 and less than or equal to the depth of the fourth groove 24 , so as to prevent the first protective glue 50 from spilling onto the isolation film 30 after filling the groove, and preventing the thickness of the local area from increasing.
  • the first protective glue 50 is located in the middle of the corresponding groove, so that a gap is left between the peripheral side and the negative electrode active material layer 22 to reduce the first protection Glue 50 overflow problem when filling. It can be understood that, in other embodiments, the peripheral side of the first protective glue 50 can also be in contact with the negative electrode active material layer 22 , and the present application is not limited to this.
  • the positive electrode sheet 10 includes a first end 101 and a second end 102 arranged oppositely, and the direction extending from the first end 101 to the second end 102, that is, the direction indicated by the arrow B in FIG. 2,
  • the width of the positive electrode tab 41 is smaller than the width of the second groove 23 , so as to avoid accidental contact between the positive electrode tab 41 and the negative electrode active material layer 22 on the edge of the second groove 23 and cause a short circuit.
  • the widths of the first groove 13 , the third groove 14 , the second groove 23 and the fourth groove 24 are approximately the same, so as to simplify the manufacturing process of the electrode assembly 100 . It can be understood that, in other embodiments, the widths of the first groove 13 , the third groove 14 , the second groove 23 and the fourth groove 24 may also be different.
  • the electrode assembly 100 further includes a first insulating member 60 and a second insulating member 70.
  • the first insulating member 60 is provided on the positive electrode sheet 10
  • the second insulating member 70 is provided on the negative electrode sheet 20 .
  • the two first insulating members 60 cover the first groove 13 and the third groove 14 respectively, and the first insulating members 60 cover part of the positive electrode active material layer 12 .
  • the two second insulating members 70 cover the second groove 23 and the fourth groove 24 respectively, and the second insulating members 70 cover part of the negative electrode active material layer 22 .
  • the projected area of the first insulating member 60 in the forward direction is larger than that of the first insulating member 60 .
  • the projected area of the two insulators 70 in the forward direction so that the uncovered area of the negative electrode active material layer 22 is larger than the uncovered area of the positive electrode active material layer 12, so that there are enough lithium insertion positions on the negative electrode sheet 20 to reduce lithium precipitation problem occurs.
  • the width of the first insulating member 60 is greater than the width of the second insulating member 70 .
  • the width of the first protective glue 50 is W1
  • the width of the second groove 23 is W2
  • the width of the second insulating member 70 is W3
  • the width of the first insulating member 60 is W4, wherein W1 ⁇ W2 ⁇ W3 ⁇ W4.
  • the positive electrode sheet 10 further includes a first side 103 and a second side 104 disposed opposite to each other, and the first end 101 and the second end 102 are connected to the first side 103 and the second side 104 .
  • the direction extending from the first side edge 103 to the second side edge 104 that is, the direction indicated by the arrow C in FIG. 3 , the length of the first protective glue 50 is L1 , and the length of the second groove 23 is L2, the length of the second insulating member 70 is L3, and the length of the first insulating member 60 is L4, where L1 ⁇ L2 ⁇ L3 ⁇ L4.
  • the thickness of the first protective glue is T1
  • the depth of the second groove 23 is T2 , where T1 ⁇ T2 .
  • the size of the first groove 13 is the same as the size of the third groove 14 .
  • the size of the second groove 23 is the same as that of the fourth groove 24 .
  • the dimensional relationship between the second groove 23 and the first protective glue 50 satisfies: 1mm ⁇ L2-L1 ⁇ 5mm, 1mm ⁇ W2-W1 ⁇ 5mm, 0 ⁇ m ⁇ T2-T1 ⁇ 20 ⁇ m .
  • the thickness of the first protective glue 50 can be customized according to the actual thickness of the negative electrode active material layer 22 after compaction.
  • the dimensional relationship between the second groove 23 and the second insulating member 70 satisfies: 1mm ⁇ L3-L2 ⁇ 5mm, and 1mm ⁇ W3-W2 ⁇ 5mm.
  • the dimensional relationship between the first insulating member 60 and the second insulating member 70 satisfies that 1 mm ⁇ L4-L3 ⁇ 10mm, and 1mm ⁇ W4-W3 ⁇ 10mm.
  • the negative electrode tabs 42 are electrically connected to the negative electrode current collector 21 .
  • the negative electrode tabs 42 and the positive electrode tabs 41 are arranged in a similar manner, and can be modified adaptively according to the polarity properties of the positive electrode sheet 10 and the negative electrode sheet 20 , which will not be repeated here.
  • the electrode assembly 200 of the second embodiment is substantially the same as the electrode assembly 100 of the first embodiment, except that the negative electrode sheet 20 of the electrode assembly 200 is not provided with a covering second groove 23 and the second insulating member 70 of the fourth groove 24 . Since the second insulating member 70 is omitted, the size of the first insulating member 60 can be reduced accordingly, which is beneficial to improve the energy density of the electrode assembly 200 .
  • the dimensional relationship between the first insulating member 60 and the second groove 23 satisfies that 1mm ⁇ L4-L2 ⁇ 10mm, and 1mm ⁇ W4-W2 ⁇ 10mm.
  • the electrode assembly 300 of the third embodiment is substantially the same as the electrode assembly 100 of the first embodiment, the difference is that in the electrode assembly 300 , the first protective glue 50 is filled to the second In the groove 23 and the fourth groove 24 , the peripheral side of the first protective glue 50 contacts the negative active material layer 22 to eliminate the gap between the first protective glue 50 and the periphery of the second groove 23 or the fourth groove 24 .
  • the first protective glue 50 will not generate fluidity after curing, and eliminating the gap in the groove is beneficial to prevent the active material from overflowing during the subsequent compression process of the electrode assembly 300 , and improve the compression resistance and service life of the electrode assembly 300 .
  • the width of the first protective glue 50 is W1
  • the length of the first protective glue 50 is L1.
  • the electrode assembly 400 of the fourth embodiment is substantially the same as the electrode assembly 300 of the third embodiment, the difference is that the negative electrode sheet 20 of the electrode assembly 400 is not provided with a covering second groove 23 and the second insulating member 70 of the fourth groove 24 .
  • the dimensional relationship between the first insulating member 60 and the second groove 23 satisfies that 1mm ⁇ L4-L2 ⁇ 10mm, and 1mm ⁇ W4-W2 ⁇ 10mm.
  • the second protective glue 80 is filled into the first groove 13 and the third groove 14 with an equal area, and the peripheral side of the second protective glue 80 contacts the positive electrode active material layer 12 .
  • the second protective glue 80 will not generate fluidity after curing. Eliminating the gap in the groove is beneficial to prevent the active material from overflowing during the subsequent compression process of the electrode assembly 500 , and improve the compression resistance and service life of the electrode assembly 500 .
  • the projected area of the first groove 13 is larger than that of the second groove 23 projected area.
  • the size of the first groove 13 is the same as the size of the third groove 14 .
  • the size of the second groove 23 is the same as that of the fourth groove 24 .
  • the width of the second protective glue 80 is the same as the width of the first groove 13 , both of which are W5 .
  • the length of the second protective glue 80 is the same as the length of the first groove 13 , and both are L5 .
  • the first groove 13 and the third groove 14 have the same size, the depth thereof is T3, and the thickness of the second protective glue 80 is T4, where 0 ⁇ m ⁇ T4 ⁇ T3 ⁇ 20 ⁇ m.
  • the thickness of the second protective glue 80 is less than or equal to the depth of the first groove 13 and the third groove 14 .
  • the width of the positive tab 41 is W0 and the length is L0.
  • the width of the second groove 23 is W2 and the length is L2. Among them, 1mm ⁇ L2-L0 ⁇ 5mm, 1mm ⁇ W2-W0 ⁇ 5mm.
  • the dimensional relationship between the first groove 13 and the second groove 23 satisfies: 1mm ⁇ L5-L2 ⁇ 10mm, 1mm ⁇ W5-W2 ⁇ 10mm.
  • the embodiments of the present application further provide an electrochemical device (not shown in the figure), comprising a packaging case (not shown in the figure) and the electrode assembly described in any one of the above embodiments or a combination of embodiments, the electrode assembly is accommodated in the in the packaging case.

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)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)
  • Connection Of Batteries Or Terminals (AREA)

Abstract

本申请提供了一种电极组件，包括正极片、负极片、隔离膜和正极极耳。正极片包括正极集流体和设置于所述正极集流体表面的正极活性物质层，负极片包括负极集流体和设置在所述负极集流体表面的负极活性物质层，隔离膜设置于正极片与负极片之间。所述正极活性物质层上设有第一凹槽，所述正极极耳的一端设置于所述第一凹槽内，且电连接所述正极集流体。所述负极活性物质层上设有第二凹槽，所述第二凹槽与所述第一凹槽对应，所述第二凹槽沿所述电极组件的厚度方向延伸至所述负极集流体，所述第二凹槽内设有第一保护胶，保证凹槽处与极片主体区域的厚度一致性，改善极耳位置处的欠压问题，降低短路风险。本申请还提供一种具有上述电极组件的电化学装置。

Description

电极组件和电化学装置 技术领域
本申请涉及电池领域，尤其涉及一种电极组件和具有该电极组件的电化学装置。
背景技术
锂离子电池如今被广泛应用于消费类电子和电动工具等便捷化应用场景中，快充型设计的电芯在市场应用占比越来越高。近年来随着快充型电芯的发展，需求更加低内阻的电芯结构。在此基础上开发应用极片中间开槽的结构，使极耳居中焊接位于极片中间，该结构能够显著降低电芯内阻，提高充放电速度。但是该结构中，凹槽位置处存在局部较大厚度差，使极片表面的一致性变差，导致电芯和化成过程中部分区域欠压，电芯循环后期缺陷区域会产生界面浸润不良导致的析锂问题，容易发生内短路引起的热失控。
发明内容
鉴于上述状况，本申请提供一种电极组件和具有该电极组件的电化学装置，通过在凹槽中填充第一保护胶，保证凹槽处与极片主体区域的厚度一致性，改善极耳位置处的欠压问题，降低析锂问题的风险。
本申请的实施例提供一种电极组件，包括正极片、负极片、隔离膜和正极极耳。所述正极片包括正极集流体和设置于所述正极集流体表面的正极活性物质层。所述负极片包括负极集流体和设置在所述负极集流体表面的负极活性物质层。所述隔离膜设置于所述正极片与所述负极片之间。所述正极极耳电连接所述正极集流体。所 述正极活性物质层上设有第一凹槽，所述正极极耳的一端设置于所述第一凹槽内，且电连接所述正极集流体。所述负极活性物质层上设有第二凹槽，所述第二凹槽与所述第一凹槽对应，所述第二凹槽沿所述电极组件的厚度方向延伸至所述负极集流体，所述第二凹槽内设有第一保护胶。
在一些实施例中，沿所述电极组件的厚度方向，所述第一保护胶的厚度小于或等于所述第二凹槽的深度。
在一些实施例中，所述正极片包括相对设置的第一端和第二端，从所述第一端向所述第二端延伸的方向，所述正极极耳的宽度小于所述第二凹槽的宽度。
在一些实施例中，所述第一保护胶的周侧接触所述负极活性物质层。
在一些实施例中，所述正极片、所述隔离膜和所述负极片依序卷绕设置。
在一些实施例中，所述正极片上设有第一绝缘件，所述第一绝缘件覆盖所述第一凹槽。
在一些实施例中，所述第一绝缘件覆盖部分所述正极活性物质层。
在一些实施例中，所述负极片上设有第二绝缘件，所述第二绝缘件覆盖所述第二凹槽。
在一些实施例中，所述第二绝缘件覆盖部分所述负极活性物质层。
在一些实施例中，沿所述电极组件的厚度方向，所述第一绝缘件的投影面积大于所述第二绝缘件的投影面积。
在一些实施例中，所述第一凹槽内设有第二保护胶。
在一些实施例中，所述第二保护胶的周侧接触所述正极活性物质层。
在一些实施例中，所述第一保护胶为胶纸、涂覆的胶层或填充的胶水。
在一些实施例中，所述第一保护胶的宽度为W1，所述第二凹槽的宽度为W2，所述第二绝缘件的宽度为W3，所述第一绝缘件的宽度为W4，其中，W1＜W2＜W3＜W4。
在一些实施例中，所述第一保护胶的长度为L1，所述第二凹槽的长度为L2，所述第二绝缘件的长度为L3，所述第一绝缘件的长度为L4，其中，L1＜L2＜L3＜L4。
在一些实施例中，所述第一保护胶的厚度为T1，所述第二凹槽的深度为T2，其中，T1≤T2。
在一些实施例中，所述第二凹槽与所述第一保护胶之间的尺寸关系满足：0mm≤L2-L1≤5mm，0mm≤W2-W1≤5mm，0μm≤T2-T1≤20μm。
在一些实施例中，所述第二凹槽与所述第一保护胶之间的尺寸关系满足：1mm≤L2-L1≤5mm，1mm≤W2-W1≤5mm，0μm≤T2-T1≤20μm。
在一些实施例中，所述第二凹槽与所述第二绝缘件之间的尺寸关系满足：1mm≤L3-L2≤5mm，1mm≤W3-W2≤5mm。
在一些实施例中，所述第一绝缘件和所述第二绝缘件之间的尺寸关系满足，1mm≤L4-L3≤10mm，1mm≤W4-W3≤10mm。
在一些实施例中，第一绝缘件与第二凹槽之间的尺寸关系满足，1mm≤L4-L2≤10mm，1mm≤W4-W2≤10mm。
在一些实施例中，第一保护胶与第二凹槽之间的尺寸关系满足：W1＝W2，L1＝L2。
在一些实施例中，正极极耳的宽度为W0，正极极耳位于第一凹槽内的长度为L0，其中，L0＜L1＝L2，W0＜W1＝W2。
在一些实施例中，第一绝缘件与第二凹槽之间的尺寸关系满足， 1mm≤L4-L2≤10mm，1mm≤W4-W2≤10mm。
在一些实施例中，第二保护胶的宽度与第一凹槽的宽度相同，均为W5；第二保护胶的长度与第一凹槽的长度相同，均为L5，第一凹槽与第二凹槽之间的尺寸关系满足：1mm≤L5-L2≤10mm，1mm≤W5-W2≤10mm。
本申请的实施例还提供一种电化学装置，包括包装壳和上述电极组件，电极组件收容在包装壳中。
上述电极组件通过在第二凹槽中填充第一保护胶，保证第二凹槽处与极片主体区域的厚度一致性，改善极耳位置处的欠压问题，降低析锂问题的风险。此外，上述电极组件中，所述第二凹槽与所述第一凹槽对应，且沿所述电极组件的厚度方向延伸至所述负极集流体，给正极极耳的焊印毛刺预留足够的空间，防止焊印毛刺贯穿第二凹槽；即使当焊印毛刺贯穿第二凹槽时，正极极耳电连接的正极集流体也是与负极集流体接触，而不是与负极活性物质层接触，防止最危险的短路情况发生。
附图说明
图1为电极组件在第一实施例中的卷绕结构示意图。
图2为图1所示电极组件的局部结构示意图，其中隔离膜被省略。
图3为图1所示电极组件中正极片和负极片的展开结构示意图。
图4为电极组件在第二实施例中的卷绕结构示意图。
图5为图4所示电极组件的局部结构示意图，其中隔离膜被省略。
图6为图4所示电极组件中正极片和负极片的展开结构示意图。
图7为电极组件在第三实施例中的卷绕结构示意图。
图8为图7所示电极组件的局部结构示意图，其中隔离膜被省 略。
图9为图7所示电极组件中正极片和负极片的展开结构示意图。
图10为电极组件在第四实施例中的卷绕结构示意图。
图11为图10所示电极组件的局部结构示意图，其中隔离膜被省略。
图12为图10所示电极组件中正极片和负极片的展开结构示意图。
图13为电极组件在第五实施例中的卷绕结构示意图。
图14为图13所示电极组件的局部结构示意图，其中隔离膜被省略。
图15为图13所示电极组件中正极片和负极片的展开结构示意图。
主要元件符号说明：
电极组件                100,200,300,400,500
正极片                  10
第一端                  101
第二端                  102
第一侧边                103
第二侧边                104
正极集流体              11
正极活性物质层          12
第一凹槽                13
第三凹槽                14
负极片                  20
负极集流体              21
负极活性物质层          22
第二凹槽                23
第四凹槽                24
隔离膜                  30
正极极耳                41
负极极耳                42
第一保护胶              50
第一绝缘件              60
第二绝缘件              70
第二保护胶              80
具体实施方式：
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本申请一部分实施例，而不是全部的实施例。
需要说明的是，当元件被称为″固定于″另一个元件，它可以直接在另一个元件上或者也可以存在居中的元件。当一个元件被认为是″连接″另一个元件，它可以是直接连接到另一个元件或者可能同时存在居中元件。当一个元件被认为是″设置于″另一个元件，它可以是直接设置在另一个元件上或者可能同时存在居中元件。本文所使用的术语″垂直的″、″水平的″、″左″、″右″以及类似的表述只是为了说明的目的。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。本文中在本申请的说明书中所使用的术语只是为了描述具体的实施方式的目的，不是旨在于限制本申请。本文所使用的术语″或/及″包括一个或多个相关的所列项目的任意的和所有的组合。
本申请实施例提供了一种电极组件，包括正极片、负极片、隔 离膜和正极极耳。所述正极片包括正极集流体和设置于所述正极集流体表面的正极活性物质层。所述负极片与所述正极片堆叠设置，包括负极集流体和设置在所述负极集流体表面的负极活性物质层。所述隔离膜设置于所述正极片与所述负极片之间。所述正极极耳电连接所述正极集流体。所述正极活性物质层上设有第一凹槽，所述正极极耳的一端设置于所述第一凹槽内，且电连接所述正极集流体。所述负极活性物质层上设有第二凹槽，所述第二凹槽与所述第一凹槽对应，所述第二凹槽沿所述电极组件的厚度方向延伸至所述负极集流体，所述第二凹槽内设有第一保护胶。
上述电极组件通过在第二凹槽中填充第一保护胶，保证第二凹槽处与极片主体区域的厚度一致性，改善极耳位置处的欠压问题，降低析锂问题的风险。所述第二凹槽与所述第一凹槽对应，且沿所述电极组件的厚度方向延伸至所述负极集流体，是为了给正极极耳的焊印毛刺预留足够的空间，防止焊印毛刺贯穿第二凹槽；即使当焊印毛刺贯穿第二凹槽时，正极极耳电连接的正极集流体也是与负极集流体接触，而不是与负极活性物质层接触，防止最危险的短路情况发生。
本申请的一些实施方式作详细说明。在不冲突的情况下，下述的实施方式及实施方式中的特征可以相互组合。
实施例一
请参阅图1、图2和图3，电极组件100包括正极片10、负极片20、隔离膜30、正极极耳41和负极极耳42。所述正极片10与所述负极片20堆叠并卷绕设置，所述隔离膜30设置于所述正极片10和所述负极片20之间。所述正极极耳41电连接所述正极片10，所述负极极耳42电连接所述负极片20。
具体地，请参阅图2，所述正极片10包括正极集流体11和设置于所述正极集流体11表面的正极活性物质层12。本实施例中， 所述正极集流体11的相对两侧表面分别设置有所述正极活性物质层12。所述正极活性物质层12上分别设有第一凹槽13和第三凹槽14，沿所述电极组件100的厚度方向，即图2中箭头A指示的方向，所述第一凹槽13与所述第三凹槽14的投影重叠，所述正极集流体11对应所述第一凹槽13的部分露出所述第一凹槽13和所述第三凹槽14。所述正极极耳41的一端设置于所述第一凹槽13内，并电连接所述正极集流体11。所述正极极耳41与所述正极集流体11的连接方式包括但不限于超声波焊接、热熔焊接等。所述第三凹槽14的设置，一方面有利于避免焊接过程中，因焊头焊座被正极活性物质层12污染而导致的焊接失败，另一方面，当极耳厚度大于第一凹槽13的深度时，第一凹槽13内的正极集流体11可以朝向第三凹槽14凹陷，从而使第三凹槽14可以吸收正极极耳41的厚度，避免正极极耳41凸出于正极片10的表面，维持电极组件100的整体厚度均匀。
所述负极片20包括负极集流体21和设置在所述负极集流体21表面的负极活性物质层22。本实施例中，所述负极集流体21的相对两侧表面分别设置有所述负极活性物质层22。所述负极活性物质层22上间隔设置第二凹槽23和第四凹槽24，所述第二凹槽23与所述第一凹槽13对应，所述第四凹槽24与所述第三凹槽14对应。进一步地，所述第二凹槽23沿所述电极组件100的厚度方向延伸至所述负极集流体21，所述第四凹槽24沿所述电极组件100的厚度方向延伸至所述负极集流体21，以避免第二凹槽23和第四凹槽24内因析锂产生的毛刺接触极耳而导致电极组件100的内短路问题。电极组件100的厚度方向为图2中箭头A指示方向。所述第二凹槽23与所述第一凹槽13对应，所述第四凹槽24与所述第三凹槽14对应，且第二凹槽23和第四凹槽24沿所述电极组件100的厚度方向延伸至所述负极集流体21，也是为了给正极极耳41的焊印毛刺 预留足够的空间，防止焊印毛刺贯穿第二凹槽23；即使当焊印毛刺贯穿第二凹槽23时，正极极耳41电连接的正极集流体11也是与负极集流体21接触，而不是与负极活性物质层22接触，防止最危险的短路情况发生。
所述第二凹槽23和所述第四凹槽24内还设有第一保护胶50，以解决凹槽本身去除活性物质后产生的厚度差，保证凹槽处与极片主体区域的厚度一致性，从而维持电极组件100的循环性能一致性和改善电极组件100的动力学性能。所述第一保护胶50包括但不限于胶纸或者其他流动性填充胶水，具有绝缘性能且能够弥补凹槽处的厚度差即可。
请再次参阅图2沿所述电极组件100的厚度方向，所述第一保护胶50的厚度小于或等于所述第二凹槽23的深度，且小于或等于所述第四凹槽24的深度，以避免第一保护胶50填充槽位后溢散到隔离膜30上，防止局部区域厚度增加。请参阅图3，在第一实施例中，所述第一保护胶50位于对应凹槽的中部，从而使其周侧与所述负极活性物质层22之间留有间隙，以减少第一保护胶50填充时的溢散问题。可以理解，在其他实施例中，所述第一保护胶50的周侧也能够与所述负极活性物质层22接触，本申请不限定于此。
进一步地，所述正极片10包括相对设置的第一端101和第二端102，从所述第一端101向所述第二端102延伸的方向，即图2中箭头B指示的方向，所述正极极耳41的宽度小于所述第二凹槽23的宽度，以避免正极极耳41与第二凹槽23边缘的负极活性物质层22意外接触而短路。进一步地，所述第一凹槽13、第三凹槽14、第二凹槽23和第四凹槽24的宽度大致相同，以便简化电极组件100的制程。可以理解，在其他实施例中，所述第一凹槽13、第三凹槽14、第二凹槽23和第四凹槽24的宽度也可以不同。
请再次参阅图2和图3，所述电极组件100还包括第一绝缘件 60和第二绝缘件70。所述第一绝缘件60设于所述正极片10，所述第二绝缘件70设于所述负极片20。两个所述第一绝缘件60分别覆盖所述第一凹槽13和所述第三凹槽14，且所述第一绝缘件60覆盖部分所述正极活性物质层12。两个所述第二绝缘件70分别覆盖所述第二凹槽23和所述第四凹槽24，且所述第二绝缘件70覆盖部分所述负极活性物质层22。在正极活性物质层12和负极活性物质层22尺寸相等的情况下，沿所述正极片10和所述负极片20的堆叠方向，所述第一绝缘件60正向的投影面积大于所述第二绝缘件70正向的投影面积，以使负极活性物质层22的未被覆盖的面积大于正极活性物质层12未被覆盖的面积，让负极片20上有足够的嵌锂位置，减少析锂问题的发生。具体地，沿图2中箭头A指示的方向，所述第一绝缘件60的宽度大于所述第二绝缘件70的宽度。
所述第一绝缘件60和第二绝缘件70的厚度为10μm-20μm，以避免增加电极组件100的局部厚度。第一绝缘件60与第二绝缘件70的材料相同，包括但不限于胶纸等绝缘材料。在本实施例中，第一绝缘件60与第二绝缘件70为单面胶带，包括基材层和胶层，其中基材层的厚度占胶带厚度的1/5～1/4，以提供足够的刚性填充效果，减小凹槽处与极片主体部的厚度差。
在本实施例中，沿图2中箭头B指示的方向，所述第一保护胶50的宽度为W1，所述第二凹槽23的宽度为W2，所述第二绝缘件70的宽度为W3，所述第一绝缘件60的宽度为W4，其中，W1＜W2＜W3＜W4。
所述正极片10还包括相对设置的第一侧边103和第二侧边104，所述第一端101和第二端102连接所述第一侧边103和第二侧边104。从所述第一侧边103向第二侧边104延伸的方向，即图3中箭头C指示的方向，所述第一保护胶50的长度为L1，所述第二凹槽23的长度为L2，所述第二绝缘件70的长度为L3，所述第一 绝缘件60的长度为L4，其中，L1＜L2＜L3＜L4。
沿所述电极组件100的厚度方向，即图2中箭头A指示的方向，所述第一保护胶的厚度为T1，所述第二凹槽23的深度为T2，其中，T1≤T2。所述第一凹槽13的尺寸与所述第三凹槽14的尺寸相同。所述第二凹槽23的尺寸与所述第四凹槽24的尺寸相同。
基于尺寸设计需求，所述第二凹槽23与所述第一保护胶50之间的尺寸关系满足：1mm≤L2-L1≤5mm，1mm≤W2-W1≤5mm，0μm≤T2-T1≤20μm。所述第一保护胶50的厚度可以根据实际负极活性物质层22压实后的厚度进行定制。
所述第二凹槽23与所述第二绝缘件70之间的尺寸关系满足：1mm≤L3-L2≤5mm，1mm≤W3-W2≤5mm。
所述第一绝缘件60和所述第二绝缘件70之间的尺寸关系满足，1mm≤L4-L3≤10mm，1mm≤W4-W3≤10mm。
所述负极极耳42电连接所述负极集流体21。负极极耳42与正极极耳41的设置方式类似，根据正极片10和负极片20的极性性质做适应性修改即可，此处不再赘述。
第二实施例
请参阅图4、图5和图6，第二实施例的电极组件200与第一实施例的电极组件100大致相同，区别在于，电极组件200的负极片20上没有设置覆盖第二凹槽23和第四凹槽24的第二绝缘件70。由于省去第二绝缘件70，第一绝缘件60的尺寸可以相应减小，有利于提高电极组件200的能量密度。
在第二实施例中，第二凹槽23和第一保护胶50之间的尺寸关系满足：1mm≤L2-L1≤5mm，1mm≤W2-W1≤5mm，0μm≤T2-T1≤20μm。
第一绝缘件60与第二凹槽23之间的尺寸关系满足，1mm≤ L4-L2≤10mm，1mm≤W4-W2≤10mm。
第三实施例
请参阅图7、图8和图9，第三实施例的电极组件300与第一实施例的电极组件100大致相同，区别在于，电极组件300中，第一保护胶50等面积填充至第二凹槽23和第四凹槽24，第一保护胶50的周侧接触所述负极活性物质层22，以消除第一保护胶50与第二凹槽23或第四凹槽24周边的间隙。第一保护胶50固化后不会产生流动性，消除凹槽内的间隙有利于避免后续电极组件300受压过程中活性物质溢出，提升电极组件300的抗压性能和使用寿命。
请再次参阅图8和图9，第一保护胶50的宽度为W1，第一保护胶50的长度为L1。第二凹槽23的宽度为W2，第二凹槽23的长度为L2。由于第一保护胶50等面积填充至第二凹槽23，第一保护胶50与第二凹槽23之间的尺寸关系满足：W1＝W2，L1＝L2。
正极极耳41的宽度为W0，正极极耳41位于第一凹槽13内的长度为L0，其中，L0＜L1＝L2，W0＜W1＝W2。正极极耳41位于第一凹槽13内的部分完全被第一保护胶50覆盖，有利于降低正极极耳41于负极活性物质层22意外接触的可能性。
第四实施例
请参阅图10、图11和图12，第四实施例的电极组件400与第三实施例的电极组件300大致相同，区别在于，电极组件400的负极片20上没有设置覆盖第二凹槽23和第四凹槽24的第二绝缘件70。
在第四实施例中，第二凹槽23和第一保护胶50之间的尺寸关系满足：L2＝L1，W2＝W1，0μm≤T2-T1≤20μm。
第一绝缘件60与第二凹槽23之间的尺寸关系满足，1mm≤ L4-L2≤10mm，1mm≤W4-W2≤10mm。
第五实施例
请参阅图13、图14和图15，第五实施例的电极组件500与第四实施例的电极组件400大致相同，区别在于，电极组件500中没有设置第一绝缘件60，同时第一凹槽13和第三凹槽14内设有第二保护胶80。电极组件500的结构可以省去第一绝缘件60和第二绝缘件70占用的厚度空间，提高电极组件500的能量密度。另外，第一保护胶50和第二保护胶80的填充可以起到绝缘作用，同时能够保证极片表面的平整度，降低凹槽处于极片主体部之间的厚度差。
所述第二保护胶80等面积填充至第一凹槽13和第三凹槽14中，第二保护胶80的周侧接触所述正极活性物质层12。第二保护胶80固化后也不会产生流动性，消除凹槽内的间隙有利于避免后续电极组件500受压过程中活性物质溢出，提升电极组件500的抗压性能和使用寿命。
在本实施例中，为了保证负极片20上有足够的嵌锂位置，降低析锂风险，沿正极片10和负极片20的堆叠方向，第一凹槽13的投影面积大于第二凹槽23的投影面积。所述第一凹槽13的尺寸与所述第三凹槽14的尺寸相同。所述第二凹槽23的尺寸与所述第四凹槽24的尺寸相同。
请再次参阅图14和图15，在第五实施例中，第二保护胶80的宽度与第一凹槽13的宽度相同，均为W5。第二保护胶80的长度与第一凹槽13的长度相同，均为L5。第一凹槽13和第三凹槽14的尺寸相同，其深度为T3，第二保护胶80的厚度为T4，其中0μm≤T4-T3≤20μm。第二保护胶80厚度小于或等于所述第一凹槽13和所述第三凹槽14的深度。
正极极耳41的宽度为W0，长度为L0。第二凹槽23的宽度为 W2，长度为L2。其中，1mm≤L2-L0≤5mm，1mm≤W2-W0≤5mm。
第一凹槽13与第二凹槽23之间的尺寸关系满足：1mm≤L5-L2≤10mm，1mm≤W5-W2≤10mm。
本申请的实施例还提供一种电化学装置(图未示)，包括包装壳(图未示)和上述任一实施例或实施例组合所述的电极组件，所述电极组件收容在所述包装壳中。
以上实施方式仅用以说明本申请的技术方案而非限制，尽管参照以上较佳实施方式对本申请进行了详细说明，本领域的普通技术人员应当理解，可以对本申请的技术方案进行修改或等同替换都不应脱离本申请技术方案的精神和范围。

Claims (13)

  1. 一种电极组件，包括：
    正极片，包括正极集流体和设置于所述正极集流体表面的正极活性物质层；
    负极片，包括负极集流体和设置在所述负极集流体表面的负极活性物质层；
    隔离膜，设置于所述正极片与所述负极片之间；和
    正极极耳，电连接所述正极集流体；
    其特征在于，所述正极活性物质层上设有第一凹槽，所述正极极耳的一端设置于所述第一凹槽内，且电连接所述正极集流体；
    所述负极活性物质层上设有第二凹槽，所述第二凹槽与所述第一凹槽对应，所述第二凹槽沿所述电极组件的厚度方向延伸至所述负极集流体，所述第二凹槽内设有第一保护胶。
  2. 如权利要求1所述的电极组件，其特征在于，沿所述电极组件的厚度方向，所述第一保护胶的厚度小于或等于所述第二凹槽的深度。
  3. 如权利要求1所述的电极组件，其特征在于，所述正极片包括相对设置的第一端和第二端，从所述第一端向所述第二端延伸的方向，所述正极极耳的宽度小于所述第二凹槽的宽度。
  4. 如权利要求1所述的电极组件，其特征在于，所述第一保护胶的周侧接触所述负极活性物质层。
  5. 如权利要求1所述的电极组件，其特征在于，所述正极片、所述隔离膜和所述负极片依序卷绕设置。
  6. 如权利要求1所述的电极组件，其特征在于，所述正极片上设有第一绝缘件，所述第一绝缘件覆盖所述第一凹槽。
  7. 如权利要求6所述的电极组件，其特征在于，所述第一绝缘件覆盖部分所述正极活性物质层。
  8. 如权利要求6所述的电极组件，其特征在于，所述负极片上设有 第二绝缘件，所述第二绝缘件覆盖所述第二凹槽。
  9. 如权利要求8所述的电极组件，其特征在于，所述第二绝缘件覆盖部分所述负极活性物质层。
  10. 如权利要求8所述的电极组件，其特征在于，沿所述电极组件的厚度方向，所述第一绝缘件的投影面积大于所述第二绝缘件的投影面积。
  11. 如权利要求1所述的电极组件，其特征在于，所述第一凹槽内设有第二保护胶。
  12. 如权利要求11所述的电极组件，其特征在于，所述第二保护胶的周侧接触所述正极活性物质层。
  13. 一种电化学装置，包括包装壳及如权利要求1-12任一项所述的电极组件，所述电极组件收容在所述包装壳中。
PCT/CN2020/141276 2020-12-30 2020-12-30 电极组件和电化学装置 WO2022141161A1 (zh)

Priority Applications (6)

Application Number Priority Date Filing Date Title
CN202080030181.6A CN113826240B (zh) 2020-12-30 2020-12-30 电极组件和电化学装置
JP2023521134A JP2023546000A (ja) 2020-12-30 2020-12-30 電極組立体及び電気化学デバイス
EP20967506.5A EP4254538A1 (en) 2020-12-30 2020-12-30 Electrode assembly and electrochemical device
KR1020237013142A KR20230061553A (ko) 2020-12-30 2020-12-30 전극 어셈블리 및 전기화학 장치
PCT/CN2020/141276 WO2022141161A1 (zh) 2020-12-30 2020-12-30 电极组件和电化学装置
US18/215,906 US20230344019A1 (en) 2020-12-30 2023-06-29 Electrode assembly and electrochemical apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/141276 WO2022141161A1 (zh) 2020-12-30 2020-12-30 电极组件和电化学装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/215,906 Continuation US20230344019A1 (en) 2020-12-30 2023-06-29 Electrode assembly and electrochemical apparatus

Publications (1)

Publication Number Publication Date
WO2022141161A1 true WO2022141161A1 (zh) 2022-07-07

Family

ID=78924896

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/141276 WO2022141161A1 (zh) 2020-12-30 2020-12-30 电极组件和电化学装置

Country Status (6)

Country Link
US (1) US20230344019A1 (zh)
EP (1) EP4254538A1 (zh)
JP (1) JP2023546000A (zh)
KR (1) KR20230061553A (zh)
CN (1) CN113826240B (zh)
WO (1) WO2022141161A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116598674A (zh) * 2023-07-03 2023-08-15 宁德新能源科技有限公司 二次电池及电化学装置

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114284469B (zh) * 2022-01-29 2024-04-02 珠海冠宇电池股份有限公司 极片及其制备方法、电池和用电装置
CN115843394A (zh) * 2022-02-10 2023-03-24 宁德新能源科技有限公司 电芯、电池及用电设备
CN217606876U (zh) * 2022-03-25 2022-10-18 比亚迪股份有限公司 一种极芯、电池装置及电子设备
CN217280916U (zh) * 2022-03-31 2022-08-23 珠海冠宇电池股份有限公司 电芯以及电池
CN114430095B (zh) * 2022-04-06 2022-07-08 宁德新能源科技有限公司 电化学装置及电子设备
CN116031364A (zh) * 2022-10-13 2023-04-28 宁德新能源科技有限公司 一种极片、电化学装置及电子设备
CN218647976U (zh) * 2022-10-20 2023-03-17 珠海冠宇电池股份有限公司 一种电极组件及电池
CN218783074U (zh) * 2022-10-26 2023-03-31 珠海冠宇电池股份有限公司 一种电芯及电池
CN219286442U (zh) * 2023-02-08 2023-06-30 惠州亿纬锂能股份有限公司 极片及电芯
CN116581396B (zh) * 2023-07-10 2024-04-05 宁德新能源科技有限公司 电芯及用电设备

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5536279A (en) * 1993-06-24 1996-07-16 Wilson Greatbatch Ltd. Method of covering an electrode for electrochemical cells
CN204809314U (zh) * 2015-06-12 2015-11-25 宁德时代新能源科技有限公司 二次电池电芯
CN107834014A (zh) * 2017-09-18 2018-03-23 东莞市迈科新能源有限公司 一种高功率圆柱型锂离子电芯
CN110729447A (zh) * 2019-10-09 2020-01-24 惠州锂威新能源科技有限公司 一种电芯极片及电芯
CN211507765U (zh) * 2020-04-03 2020-09-15 珠海冠宇电池股份有限公司 卷芯结构

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7855009B2 (en) * 2005-09-15 2010-12-21 Greatbatch Ltd. Sandwich cathode electrochemical cell with wound electrode assembly
KR101650417B1 (ko) * 2013-10-31 2016-08-23 주식회사 엘지화학 양극 집전체에 간헐적 무지부가 형성된 젤리 롤 형태 전극 조립체를 가진 이차전지
CN203733894U (zh) * 2014-01-17 2014-07-23 宁德新能源科技有限公司 锂离子电池
CN105406028A (zh) * 2014-09-12 2016-03-16 东莞新能源科技有限公司 极片涂层的移除方法
WO2016197382A1 (zh) * 2015-06-12 2016-12-15 宁德时代新能源科技股份有限公司 二次电池电芯

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5536279A (en) * 1993-06-24 1996-07-16 Wilson Greatbatch Ltd. Method of covering an electrode for electrochemical cells
CN204809314U (zh) * 2015-06-12 2015-11-25 宁德时代新能源科技有限公司 二次电池电芯
CN107834014A (zh) * 2017-09-18 2018-03-23 东莞市迈科新能源有限公司 一种高功率圆柱型锂离子电芯
CN110729447A (zh) * 2019-10-09 2020-01-24 惠州锂威新能源科技有限公司 一种电芯极片及电芯
CN211507765U (zh) * 2020-04-03 2020-09-15 珠海冠宇电池股份有限公司 卷芯结构

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116598674A (zh) * 2023-07-03 2023-08-15 宁德新能源科技有限公司 二次电池及电化学装置
CN116598674B (zh) * 2023-07-03 2023-10-27 宁德新能源科技有限公司 二次电池及电化学装置

Also Published As

Publication number Publication date
JP2023546000A (ja) 2023-11-01
EP4254538A1 (en) 2023-10-04
CN113826240A (zh) 2021-12-21
KR20230061553A (ko) 2023-05-08
US20230344019A1 (en) 2023-10-26
CN113826240B (zh) 2023-04-28

Similar Documents

Publication Publication Date Title
WO2022141161A1 (zh) 电极组件和电化学装置
JP4438784B2 (ja) 蓄電装置
WO2023088428A1 (zh) 极片和电池
KR20230008141A (ko) 배터리 및 전자기기
WO2022052120A1 (zh) 电化学装置及电子装置
CN103109408A (zh) 堆叠二次电池
JP2012014935A (ja) 電池
US10741818B2 (en) Cell and battery using same
WO2023088434A1 (zh) 极片和电池
CN216354304U (zh) 极片及电池
JP2022537227A (ja) 電極アセンブリ及び電池
WO2023071835A1 (zh) 一种电芯、电池及电子设备
CN115458879B (zh) 电芯及电芯制造方法
JP4603857B2 (ja) リチウムイオン二次電池およびその製造方法
CN215070100U (zh) 一种电芯
WO2022022525A1 (zh) 一种双极性集流体、极片、电芯和二次电池
JP2009181899A (ja) 積層式電池
JP2012164476A (ja) ラミネート形電池およびそれを備えた積層型電池
CN219778914U (zh) 电芯结构、锂电池和电子设备
JP5501270B2 (ja) 塗布型電極群を用いた電池
CN112909219A (zh) 一种电极组件和锂离子电池
EP4123792A1 (en) Pouch-type secondary battery and method for manufacturing the same
CN216928675U (zh) 一种电池
WO2021189380A1 (zh) 电化学装置和电子装置
JP2014137883A (ja) 二次電池および二次電池製造方法

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: 20967506

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2023521134

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20237013142

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2020967506

Country of ref document: EP

Effective date: 20230629

NENP Non-entry into the national phase

Ref country code: DE