WO2023039706A1 - 电芯、电池及用电设备 - Google Patents

电芯、电池及用电设备 Download PDF

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Publication number
WO2023039706A1
WO2023039706A1 PCT/CN2021/118150 CN2021118150W WO2023039706A1 WO 2023039706 A1 WO2023039706 A1 WO 2023039706A1 CN 2021118150 W CN2021118150 W CN 2021118150W WO 2023039706 A1 WO2023039706 A1 WO 2023039706A1
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WO
WIPO (PCT)
Prior art keywords
pole piece
positive
layer
current collector
battery cell
Prior art date
Application number
PCT/CN2021/118150
Other languages
English (en)
French (fr)
Inventor
柯招清
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 CN202180006011.9A priority Critical patent/CN114730943A/zh
Priority to PCT/CN2021/118150 priority patent/WO2023039706A1/zh
Publication of WO2023039706A1 publication Critical patent/WO2023039706A1/zh

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    • 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
    • H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside 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
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/102—Primary casings, jackets or wrappings of a single cell or a single battery 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 of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/186—Sealing members characterised by the disposition of the sealing members
    • H01M50/188—Sealing members characterised by the disposition of the sealing members the sealing members being arranged between the lid and terminal
    • 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
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • 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
    • 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 technical field of batteries, and in particular to a battery cell, a battery and electric equipment.
  • a double-layer empty foil area is generally set on the outermost ring of the battery cell, thereby forming a protection zone on opposite sides of the battery core in the thickness direction.
  • the protection zone can give priority to short circuit .
  • the double-layer empty foil area set on the outermost ring of the battery cannot exert its capacity, resulting in low energy density of the battery.
  • An embodiment of the present application provides an electric core, which includes an electrode assembly and a packaging bag for accommodating the electrode assembly.
  • the electrode assembly includes a wound positive pole piece, a first separator and a negative pole piece.
  • the positive pole piece includes a positive current collector and a positive active material layer coated on the positive current collector.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on the negative electrode current collector. Pointing from the winding center of the electrode assembly to the direction outside the electrode assembly, define the outermost pole piece of the electrode assembly as the pole piece without the positive pole piece or the negative pole piece covered by the periphery, and the outermost circle pole piece includes the positive pole piece and the negative pole pole piece.
  • the electrode assembly is a wound structure.
  • the positive pole piece and the negative pole piece in the outermost circle of pole pieces are preferentially short-circuited.
  • the positive pole piece or the negative pole piece in the outermost pole piece is short-circuited with the metal layer in the packaging bag, and the short-circuit position is located on the outermost pole piece of the battery cell, not inside the battery core, which is conducive to heat dissipation to avoid electric shock.
  • the core burns or explodes, thereby improving the safety of the battery core.
  • the use of one layer of empty foil area is reduced while improving the safety of the battery cell, thereby increasing the energy density of the battery cell.
  • the electrode assembly includes two oppositely arranged first main planes and second main planes, and the outermost positive electrode piece includes a first end, the first end Located on the first main plane, the outermost negative pole piece includes a second ending end, and the second ending end is arranged on the second main plane.
  • the first tail end includes a first section and a second section, and along the winding direction of the first tail end, the second section is arranged at the outer end of the first section; the first section is arranged at the second main section. plane, the second section is wound around the corner of the cell to the first main plane, the inner ring of the positive electrode current collector corresponding to the first section is coated with a positive electrode active material layer, and the positive electrode current collector corresponding to the second section is not coated with a positive electrode active material layer.
  • the positive electrode active material layer is coated on the inner ring of the positive current collector corresponding to the first segment, so that the first segment and the negative electrode sheet surrounded by it can exert capacity, thereby increasing the energy density of the cell.
  • the short circuit of the positive electrode current collector and/or the negative electrode current collector is relatively safe.
  • the fluid is short-circuited when the battery is abused by external mechanical forces such as acupuncture, thereby improving the safety of the battery.
  • the outer ring of the negative electrode current collector corresponding to the second ending end is not coated with the negative electrode active material layer.
  • the battery cell further includes a second membrane, and the second membrane covers the end of the second end.
  • the battery cell further includes a positive tab provided on the positive pole piece.
  • the packaging bag includes a fusion layer, a metal layer and a protective layer stacked in sequence.
  • the fusion layer is arranged on the inner side of the metal layer for heating and melting to seal the packaging bag
  • the protective layer is arranged on the outer side of the metal layer.
  • the packaging bag is provided with a sealing part, and the positive electrode tab is electrically connected to the metal layer and protrudes from the sealing part. The sealability of the pouch seal is improved by the fusion layer and the seal. Improve the structural strength of the packaging bag through the protective layer.
  • the metal layer in the packaging bag can be short-circuited with the positive electrode current collector by electrically connecting the metal layer through the positive tab, and the short-circuit position is located in the outermost packaging bag of the battery cell.
  • the inside of the battery core it is conducive to heat dissipation to avoid burning or explosion of the battery core, thereby improving the safety of the battery core.
  • the fusion layer in the sealing part is provided with a through hole, and the positive electrode tab is electrically connected to the metal layer through the through hole.
  • the battery cell also includes a tab glue layer through which the positive pole tab passes, and the tab glue layer is partly arranged in the sealing part. The convenience of connecting the positive tab to the metal layer is improved through the through hole. The sealing performance of the packaging bag is improved through fusion bonding of the tab glue layer and the fusion layer.
  • the tab glue layer is provided with a melting part corresponding to the through hole, and the melting part is used for synchronous melting with the fusion layer to expose the positive electrode tab in the melting part, and the positive electrode tab passes through the through hole.
  • the holes are electrically connected to the metal layer.
  • the sealability of the cell package is improved through the melting and bonding of the tab glue layer and the fusion layer, and the simultaneous melting of the melting portion and the fusion layer.
  • the exposed positive tab is electrically connected to the metal layer through the through hole, so that the metal layer and the positive current collector are preferentially short-circuited when the battery encounters mechanical external force abuse such as acupuncture, thereby improving the safety of the battery.
  • the tab glue layer is provided with a conductive part corresponding to the through hole, and the conductive part passes through the through hole and contacts the metal layer to electrically connect the metal layer.
  • the sealability of the cell package is improved by melting and bonding the tab glue layer and the fusion layer.
  • the conductive part passes through the through hole and touches the metal layer, so that the positive electrode tab is electrically connected to the metal layer, so that the metal layer and the positive electrode current collector are preferentially short-circuited when the battery encounters mechanical external force abuse such as acupuncture, thereby improving the battery life. security.
  • the tab glue layer is a conductive glue layer
  • the part of the tab glue layer corresponding to the through hole passes through the through hole and contacts the metal layer to electrically connect the metal layer.
  • the sealability of the cell package is improved by melting and bonding the tab glue layer and the fusion layer.
  • the tab glue layer made of conductive adhesive can electrically connect the positive tab to the metal layer, so that the metal layer and the positive current collector will preferentially short-circuit when the battery encounters mechanical external force abuse such as acupuncture, thereby improving the performance of the battery. security.
  • the electric core further includes a conductive part
  • the protective layer is provided with a concave part exposing the metal layer
  • one end of the conductive part is electrically connected to the metal layer at the concave part
  • the second end of the conductive part is connected to the
  • the positive pole tab outside the packaging bag is electrically connected.
  • the positive tab and the metal layer are respectively electrically connected through conductive parts, so that the positive tab is electrically connected to the metal layer, so that the metal layer and the positive current collector are preferentially short-circuited when the battery encounters mechanical external force such as acupuncture, thereby improving the electric current. core security.
  • An embodiment of the present application provides a battery, which includes a casing, and the battery further includes any one of the above-mentioned electric cores, and the electric cores are arranged in the casing.
  • the positive pole piece and the negative pole piece in the outermost circle of pole pieces are preferentially short-circuited.
  • the positive pole piece or the negative pole piece in the outermost pole piece is short-circuited with the metal layer in the packaging bag, and the short-circuit position is located on the outermost pole piece of the battery cell, not inside the battery core, which is conducive to heat dissipation to avoid electric shock.
  • the core burns or explodes, thereby improving the safety of the battery.
  • An embodiment of the present application provides an electric device, including the above-mentioned battery.
  • the positive pole piece and the negative pole piece in the outermost circle of pole pieces are preferentially short-circuited.
  • the positive pole piece or the negative pole piece in the outermost pole piece is short-circuited with the metal layer in the packaging bag, and the short-circuit position is located on the outermost pole piece of the battery cell, not inside the battery core, which is conducive to heat dissipation to avoid electric shock. Core combustion or explosion, thereby improving the safety of electrical equipment.
  • the positive pole piece and the negative pole piece in the outermost circle of pole pieces are preferentially short-circuited.
  • the positive pole piece or the negative pole piece in the outermost pole piece is short-circuited with the metal layer in the packaging bag, and the short-circuit position is located on the outermost pole piece of the battery cell, not inside the battery core, which is conducive to heat dissipation to avoid electric shock.
  • the core burns or explodes, thereby improving the safety of the battery core.
  • the use of one layer of empty foil area is reduced while improving the safety of the battery cell, thereby increasing the energy density of the battery cell.
  • FIG. 1 is a first top view structural diagram of a battery cell in an embodiment of the present application.
  • FIG. 2 is an enlarged schematic diagram of a first partial structure of a battery cell in an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a first side structure of a battery cell in an embodiment of the present application.
  • Fig. 4 is a schematic diagram of the first connection structure between the positive tab of the battery cell and the packaging bag in an embodiment of the present application.
  • Fig. 5 is a schematic diagram of the second connection structure between the positive tab of the battery cell and the packaging bag in an embodiment of the present application.
  • Fig. 6 is a schematic diagram of the third structure of the connection between the positive tab of the battery cell and the packaging bag in an embodiment of the present application.
  • Fig. 7 is a schematic diagram of a fourth connection structure between the positive tab of the battery cell and the packaging bag in an embodiment of the present application.
  • FIG. 8 is a schematic diagram of a second top view of the battery cell in an embodiment of the present application.
  • FIG. 9 is an enlarged schematic view of the second partial structure of the battery cell in an embodiment of the present application.
  • FIG. 10 is a schematic diagram of the second side structure of the battery cell in an embodiment of the present application.
  • FIG. 11 is a schematic diagram of a third top view structure of a battery cell in an embodiment of the present application.
  • FIG. 12 is an enlarged schematic diagram of a third partial structure of a battery cell in an embodiment of the present application.
  • FIG. 13 is a schematic diagram of the third side structure of the battery cell in an embodiment of the present application.
  • An embodiment of the present application provides a battery cell, including an electrode assembly and a packaging bag for accommodating the electrode assembly.
  • the electrode assembly includes a wound positive pole piece, a first separator and a negative pole piece.
  • the positive pole piece includes a positive current collector and a positive active material layer coated on the positive current collector.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on the negative electrode current collector. Pointing from the winding center of the electrode assembly to the direction outside the electrode assembly, define the outermost pole piece of the electrode assembly as the pole piece without the positive pole piece or the negative pole piece covered by the periphery, and the outermost circle pole piece includes the positive pole piece and the negative pole pole piece.
  • An embodiment of the present application provides a battery, which includes a casing, and the battery further includes any one of the above-mentioned electric cores, and the electric cores are arranged in the casing.
  • Another embodiment of the present application provides an electric device, including the above-mentioned battery.
  • the positive pole piece and the negative pole piece in the outermost circle of pole pieces are preferentially short-circuited.
  • the positive pole piece or the negative pole piece in the outermost pole piece is short-circuited with the metal layer in the packaging bag, and the short-circuit position is located on the outermost pole piece of the battery cell, not inside the battery core, which is conducive to heat dissipation to avoid electric shock.
  • the core burns or explodes, thereby improving the safety of the battery core.
  • the use of one layer of empty foil area is reduced while improving the safety of the battery cell, thereby increasing the energy density of the battery cell.
  • the battery cell 100 of this embodiment includes an electrode assembly 10 and a packaging bag 50 for accommodating the electrode assembly 10 .
  • the electrode assembly 10 includes a wound positive pole piece 20 and a negative pole piece 30 , and a first separator 40 disposed between the positive pole piece 20 and the negative pole piece 30 .
  • the positive electrode sheet 20 includes a positive electrode collector 21 and a positive electrode active material layer 22 coated on the positive electrode collector 21 .
  • the negative electrode sheet 30 includes a negative electrode current collector 31 and a negative electrode active material layer 32 coated on the negative electrode current collector 31 .
  • the positive electrode current collector 21 includes a first surface 21 a and a second surface 21 b oppositely disposed along the thickness direction of the positive electrode current collector 21 , and the first surface 21 a and/or the second surface 21 b are used for coating the positive electrode active material layer 22 .
  • the first surface 21a faces the winding center 10a, and the second surface 21b faces away from the winding center 10a.
  • the first surface 21a is defined as the inner circle of the positive electrode collector 21
  • the second surface 21b is defined as the outer circle of the positive electrode collector 21 .
  • the negative electrode current collector 31 includes a third surface 31 a and a fourth surface 31 b oppositely disposed along the thickness direction of the negative electrode current collector 31 , and the third surface 31 a and/or the fourth surface 31 b are used for coating the negative electrode active material layer 32 .
  • the third surface 31a faces the winding center 10a, and the fourth surface 31b faces away from the winding center 10a.
  • the third surface 31a is defined as the inner circle of the negative electrode current collector 31
  • the fourth surface 31b is defined as the outer circle of the negative electrode current collector 31 .
  • the outermost pole piece 10b includes a positive pole piece 20 and a negative pole piece 30 .
  • the positive pole piece 20 and the negative pole piece 30 in the outermost circle of pole piece 10b are preferentially short-circuited.
  • the positive pole piece 20 or the negative pole piece 30 in the outermost pole piece 10b is short-circuited with the pole piece located in the inner circle of the outermost circle pole piece 10b, or the positive pole piece 20 or the negative pole piece in the outermost circle pole piece 10b
  • the sheet 30 is shorted to the metal layer in the package 50 .
  • the short-circuit position is located at the outermost pole piece 10b of the battery cell 100 , rather than inside the battery cell 100 , which is beneficial to heat dissipation to prevent the battery cell 100 from burning or exploding, thereby improving the safety of the battery cell 100 .
  • the outermost ring pole piece 10b includes the positive pole piece 20 and the negative pole piece 30 to give priority to short circuit, while improving the safety of the battery cell 100
  • the use of one layer of empty foil area is reduced, thereby increasing the energy density of the battery cell 100 .
  • the electrode assembly 10 includes two oppositely disposed first main planes 11 and second main planes 12 .
  • the outermost positive pole piece 20 includes a first ending end 23 , and the first ending end 23 is disposed on the first main plane 11 .
  • the outermost negative pole piece 30 includes a second end 33 , and the second end 33 is disposed on the second main plane 12 .
  • the first end 23 ends on the first main plane 11
  • the second end 33 ends on the second main plane 12 , so that the first end 23 and the second end 33 end on different sides of the cell 100 .
  • the first main plane 11 and/or the second main plane 12 encounter mechanical external force abuse such as acupuncture
  • the corresponding first end 23 and/or second end 33 are preferentially short-circuited, so as to improve the battery cell 100 at the same time.
  • Safety of the first main plane 11 and the second main plane 12 includes a first segment 231 and a second segment 232 .
  • the second section 232 is disposed at the outer end of the first section 231 .
  • the first section 231 is disposed on the second main plane 12 , and the second section 232 is wound around the corner of the battery core 100 to the first main plane 11 .
  • the inner ring of the positive electrode collector 21 corresponding to the first segment 231 is coated with the positive electrode active material layer 22, so that the first segment 231 and the negative electrode sheet 30 surrounded by it can exert capacity, thereby increasing the energy density of the battery cell 100.
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the short circuit of the positive current collector 21 and/or the negative current collector 31 is relatively safe, so the positive current collector 21 corresponding to the second segment 232 is not coated with positive active
  • the material layer 22 makes the positive current collector 21 short-circuit when the battery cell 100 encounters mechanical external force abuse such as acupuncture.
  • the second segment 232 is short-circuited with the pole piece located on the inner circle of the outermost pole piece 10 b, or the second segment 232 is short-circuited with the metal layer in the packaging bag 50 .
  • the short-circuit position is located at the outermost pole piece 10b of the battery cell 100 , rather than inside the battery cell 100 , which is beneficial to heat dissipation to prevent the battery cell 100 from burning or exploding, thereby improving the safety of the battery cell 100 .
  • both sides of the positive electrode collector 21 corresponding to the first segment 231 are coated with the positive electrode active material layer 22 .
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • only the inner circle of the positive electrode current collector 21 corresponding to the first segment 231 is coated with the positive electrode active material layer 22 (see FIG. 7 ), and the inner end of the first segment 231 (that is, the first segment 231 is away from the second segment) 232) on both sides of the positive electrode collector 21 connected to the positive electrode active material layer 22.
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the positive electrode current collector 21 corresponding to the first segment 231 transitions from being coated with the positive electrode active material layer 22 on both sides to only the inner ring is coated with the positive electrode active material layer 22 (see FIG. 10 ), and the inner ring is coated with the positive electrode active material layer 22 (see FIG. 10 ), and the inner ring is coated
  • the positive current collector 21 covered with the positive active material layer 22 surrounds the cell 100 at least half a circle.
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the area occupied by the second segment 232 to the first main plane 11 is greater than 0% and less than or equal to 100%.
  • the second section 232 occupies one of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% of the area of the first main plane 11, etc. kind.
  • the outer ring of the negative electrode current collector 31 corresponding to the second end 33 is not coated with the negative electrode active material layer 32, so that the negative electrode current collector 31 of the outer ring of the second section 232 encounters acupuncture or the like in the battery cell 100 A short circuit occurs when mechanical external force is abused, thereby improving the safety of the battery cell 100 .
  • the negative current collector 31 corresponding to the negative pole piece 30 surrounded by the second section 232 bypasses the corner of the battery cell 100, so that there is an additional layer of positive current collector 21 and negative current collector 31 at the corner of the battery core 100, so that a safe short circuit occurs opportunity, thereby improving the safety of the battery cell 100 .
  • the outer ring of the positive electrode sheet 20 is coated with the positive electrode current collector 21 of the positive electrode active material layer 22, and the outside is surrounded by the negative electrode sheet 30, and the inner ring of the negative electrode collector 31 corresponding to the negative electrode sheet 30 is coated with the negative electrode
  • the active material layer 32 enables the positive electrode current collector 21 coated with the positive electrode active material layer 22 and the negative electrode sheet 30 surrounding it to exert capacity, thereby increasing the energy density of the battery cell 100 .
  • only the inner ring of the negative electrode current collector 31 corresponding to the second ending end 33 is coated with the negative electrode active material layer 32, and surrounds the double-sided average electrode corresponding to the first ending end 23.
  • the positive current collector 21 coated with the positive active material layer 22 is at least one circle. Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the negative electrode current collector 31 corresponding to the second ending end 33 is not coated with the negative electrode active material layer 32 on both sides, and surrounds the positive electrode corresponding to the first ending end 23 coated with the positive electrode active material layer 22 on one side.
  • the current collector 21 has at least one turn (refer to FIG. 7 ). Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the negative electrode current collector 31 corresponding to the second end 33 transitions from the inner ring coated with the negative electrode active material layer 32 to the negative electrode active material layer 32 not coated on both sides, and the negative electrode is not coated on both sides
  • the negative current collector 31 of the active material layer 32 surrounds the positive current collector 21 coated with the positive active material layer 22 on one side corresponding to the first end 23 at least half a circle (see FIG. 10 ). Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the battery cell 100 further includes a second diaphragm 45 , and the second diaphragm 45 covers the end of the second end 33 for improving the Security at the end.
  • the end of the second tail end 33 is where the cutting surface of the outermost negative electrode piece 30 is located.
  • the second diaphragm 45 covers the end of the second end 33 and the end of the first segment 231 located on the second main plane 12 at the same time.
  • the battery cell 100 further includes a positive tab 24 disposed on the positive tab 20 , and a negative tab 34 disposed on the negative tab 30 .
  • the packaging bag 50 includes a fusion layer 52 , a metal layer 51 and a protective layer 53 stacked in sequence.
  • the fusion layer 52 is disposed on the inner surface of the metal layer 51 and is used for heating and melting to seal the packaging bag 50 .
  • the protective layer 53 is disposed on the outer surface of the metal layer 51 to improve the structural strength of the packaging bag 50 and avoid damage to the electrode assembly 10 caused by the packaging bag 50 being damaged.
  • the packaging bag 50 is provided with a sealing portion 50a, and the positive tab 24 is electrically connected to the metal layer 51 and protrudes from the sealing portion 50a, so as to improve the sealing performance of the packaging bag 50 .
  • the sealing portion 50 a is formed by extending the fusion layer 52 , the metal layer 51 and the protection layer 53 along the direction in which the tab protrudes.
  • the metal layer 51 is electrically connected to the positive electrode tab 24.
  • the metal layer 51 in the packaging bag 50 and the positive electrode current collector 21 are preferentially short-circuited, and the short-circuit position is located at the side of the battery cell 100.
  • the outermost packaging bag 50 rather than the inside of the battery cell 100 , is good for heat dissipation to prevent the battery cell 100 from burning or exploding, thereby improving the safety of the battery cell 100 .
  • the packaging bag 50 further includes an adhesive layer, and the adhesive layer is arranged between the fusion layer 52 and the metal layer 51, and between the metal layer 51 and the protective layer 53, for improving the fusion layer 52, the metal layer
  • the connection stability between the protective layer 51 and the protective layer 53 improves the structural strength of the packaging bag 50.
  • the metal layer 51 is one of aluminum or stainless steel
  • the fusion layer 52 is polyethylene plastic
  • the protective layer 53 is one of nylon or polyester resin.
  • the fusion layer 52 in the sealing portion 50 a is provided with a through hole 54 , and the positive tab 24 is electrically connected to the metal layer 51 through the through hole 54 .
  • the battery cell 100 also includes a tab adhesive layer 70 through which the positive electrode tab 24 passes, and the tab adhesive layer 70 is partially disposed in the sealing portion 50 a to further improve the sealing performance of the packaging bag 50 .
  • the structure of the tab glue layer 70 is also different.
  • the tab glue layer 70 in different embodiments is defined as the tab glue layer 70a, Tab glue layer 70b and tab glue layer 70c.
  • the tab glue layer 70 a covers the portion of the positive tab 24 located in the sealing portion 50 a.
  • the tab glue layer 70a is provided with a melting portion 71 corresponding to the through hole 54, and the melting portion 71 is used for synchronous melting with the fusion layer 52 to expose the positive electrode tab 24 in the melting portion 71, and the positive electrode tab 24 passes through the through hole 54 It is electrically connected to the metal layer 51 .
  • the fusion portion 71 and the fusion layer 52 are melted synchronously, so as to improve the sealing performance of the electric core 100. tightness.
  • the exposed positive electrode tab 24 is electrically connected to the metal layer 51 through the through hole 54, so that the metal layer 51 and the positive electrode current collector 21 are preferentially short-circuited when the battery cell 100 encounters mechanical external force abuse such as acupuncture, thereby improving the battery life of the battery cell 100. safety.
  • the tab glue layer 70 b covers the portion of the positive tab 24 located in the sealing portion 50 a.
  • the tab glue layer 70 b is provided with a conductive portion 72 corresponding to the through hole 54 , the conductive portion 72 abuts the metal layer 51 through the through hole 54 , and the positive electrode tab 24 is electrically connected to the metal layer 51 through the conductive portion 72 .
  • the sealability of the package of the battery cell 100 is improved through fusion bonding of the tab glue layer 70 b and the fusion layer 52 .
  • the conductive part 72 By setting the conductive part 72 on the tab glue layer 70b, the conductive part 72 abuts the metal layer 51 through the through hole 54, so that the positive electrode tab 24 is electrically connected to the metal layer 51, so that the metal layer 51 and the positive electrode current collector 21 are in contact with each other.
  • the battery cell 100 is abused by external mechanical force such as acupuncture, a short circuit occurs preferentially, thereby improving the safety of the battery cell 100 .
  • the tab glue layer 70c covers the portion of the positive tab 24 located in the sealing portion 50a.
  • the tab glue layer 70c is a conductive glue layer, and the portion of the tab glue layer 70c corresponding to the through hole 54 passes through the through hole 54 and contacts the metal layer 51 to electrically connect the metal layer 51 .
  • the sealability of the package of the battery cell 100 is improved by melting the tab glue layer 70c and the fusion layer 52 .
  • the corresponding part of the tab glue layer 70c and the through hole 54 abuts the metal layer 51 through the through hole 54, and the tab glue layer 70c made of conductive glue can electrically connect the positive electrode tab 24 to the metal layer 51, so that the metal layer 51 and the positive current collector 21 are preferentially short-circuited when the battery cell 100 encounters mechanical external force abuse such as acupuncture, thereby improving the safety of the battery cell 100 .
  • the battery cell 100 further includes a conductive member 60 .
  • the protection layer 53 is provided with a concave portion 55 exposing the metal layer 51 .
  • a first end of the conductive element 60 is electrically connected to the metal layer 51 at the concave portion 55 , and a second end of the conductive element 60 is electrically connected to the positive tab 24 disposed outside the packaging bag 50 .
  • a socket groove 61 is provided on a side of the conductive member 60 facing the sealing portion 50 a, and the conductive member 60 is socketed on the end of the sealing portion 50 a through the socket groove 61 .
  • the central position of the conductive member 60 ie, the second end of the conductive member 60
  • the peripheral side of the conductive element 60 passes through the concave portion 55 and abuts against the metal layer 51 in the sealing portion 50 a, so that the conductive element 60 is electrically connected to the metal layer 51 .
  • the conductive member 60 is sleeved on the end of the sealing portion 50 a through the socket groove 61 , so as to improve the sealing performance of the package of the battery cell 100 .
  • the positive electrode tab 24 and the metal layer 51 are respectively electrically connected through the conductive member 60, so that the positive electrode tab 24 is electrically connected to the metal layer 51, so that the metal layer 51 and the positive electrode current collector 21 encounter mechanical external force abuse such as acupuncture in the battery 100 When the short circuit occurs preferentially, the safety of the battery cell 100 is improved.
  • the embodiment of the present application also provides a battery (not shown), including a casing (not shown) and a battery cell 100 disposed in the casing, and the battery cell 100 may be any battery cell in the above-mentioned embodiments.
  • the battery further includes a circuit protection board (not shown), and the circuit protection board is used to monitor the voltage, current, insulation state and state of charge in the battery cell 100, and to safely manage the charging and discharging process of the battery. , carry out alarm and emergency protection processing for possible faults, and carry out safe and optimal control of battery operation.
  • An embodiment of the present application also provides an electric device (not shown), including any battery in the foregoing embodiments.
  • the first end 23 ends on the first main plane 11
  • the second end 33 ends on the second main plane 12 .
  • Both sides of the positive electrode current collector 21 corresponding to the first segment 231 are coated with the positive electrode active material layer 22 .
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the second segment 232 occupies an area range greater than 0% and less than or equal to 100% to the first main plane 11 .
  • the negative electrode current collector 31 corresponding to the second ending end 33 is only coated with the negative electrode active material layer 32 on the inner circle, and surrounds the positive electrode current collector 21 corresponding to the first ending end 23 coated with the positive electrode active material layer 22 on both sides at least one circle. Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the second diaphragm 45 covers the end of the second end 33 .
  • the first end 23 ends on the first main plane 11
  • the second end 33 ends on the second main plane 12 .
  • the positive electrode current collector 21 corresponding to the first segment 231 is only coated with the positive electrode active material layer 22 on the inner ring, and both sides of the positive electrode current collector 21 connected to the inner end of the first segment 231 are coated with the positive electrode active material layer 22 .
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the second segment 232 occupies an area range greater than 0% and less than or equal to 100% to the first main plane 11 .
  • the negative electrode current collector 31 corresponding to the second ending end 33 is not coated with the negative electrode active material layer 32 on both sides, and surrounds the positive electrode current collector 21 corresponding to the first ending end 23 coated with the positive electrode active material layer 22 on one side at least one circle . Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the second diaphragm 45 covers the end of the second end 33 .
  • the first ending end 23 ends at the first main plane 11
  • the second ending end 33 ends at the second main plane 12 .
  • the positive electrode current collector 21 corresponding to the first segment 231 transitions from being coated with the positive electrode active material layer 22 on both sides to only the inner ring being coated with the positive electrode active material layer 22 (see FIG. 7 ), and the inner ring is coated with the positive electrode active material layer 22
  • the positive current collector 21 surrounds the cell 100 at least half a circle.
  • the positive electrode current collector 21 corresponding to the second segment 232 is not coated with the positive electrode active material layer 22 .
  • the second segment 232 occupies an area range greater than 0% and less than or equal to 100% to the first main plane 11 .
  • the negative electrode current collector 31 corresponding to the second end 33 transitions from the inner ring coated with the negative electrode active material layer 32 to the negative electrode that is not coated with the negative electrode active material layer 32 on both sides, and is not coated with the negative electrode active material layer 32 on both sides.
  • the current collector 31 surrounds the positive electrode current collector 21 that is coated with the positive electrode active material layer 22 on one side corresponding to the first end 23 at least half a circle. Both sides of the negative electrode current collector 31 connected to the inner end of the second tail end 33 are coated with negative electrode active material layers 32 .
  • the second diaphragm 45 covers the end of the second end 33 .

Abstract

本申请公开了一种电芯，包括电极组件和收容所述电极组件的包装袋。所述电极组件包括卷绕设置的正极极片、第一隔膜及负极极片。所述正极极片包括正极集流体和涂覆于所述正极集流体的正极活性材料层。所述负极极片包括负极集流体和涂覆于所述负极集流体的负极活性材料层。从所述电极组件的卷绕中心指向所述电极组件外的方向，定义外围无所述正极极片或所述负极极片包覆的极片为所述电极组件的最外圈极片，所述最外圈极片包括正极极片和负极极片。本申请还公开了一种装载该电芯的电池和用电设备。上述电芯具有安全性高和能量密度高的优点。

Description

电芯、电池及用电设备 技术领域
本申请涉及电池技术领域，尤其涉及一种电芯、电池及用电设备。
背景技术
电芯在满充状态下遇到针刺等机械外力滥用时，极易引起短路。短路处产热严重并且热量无法散除，从而引发阴阳极热失控，导致电芯燃烧或爆炸，影响电芯的安全性能。现有技术中一般通过在电芯的最外圈设置双层空箔区，从而在电芯的厚度方向的相对两侧都形成保护区，当电芯遭到滥用时，保护区可以优先发生短路。但是，在电芯的最外圈设置的双层空箔区无法发挥容量，导致电芯能量密度低。
发明内容
有鉴于此，有必要提供一种提高安全性和能量密度的电芯、以及应用所述电芯的电池及用电设备。
本申请的实施例提供一种电芯，电芯包括电极组件和收容电极组件的包装袋。电极组件包括卷绕设置的正极极片、第一隔膜及负极极片。正极极片包括正极集流体和涂覆于正极集流体的正极活性材料层。负极极片包括负极集流体和涂覆于负极集流体的负极活性材料层。从电极组件的卷绕中心指向电极组件外的方向，定义外围无正极极片或负极极片包覆的极片为电极组件的最外圈极片，最外圈极片包括正极极片和负极极片。所述电极组件为卷绕结构。
本申请的实施例包括的技术效果：当电芯遇到针刺等机械外力滥用时，最外圈极片中的正极极片和负极极片优先发生短路。例如最外圈极片中的正极极片或负极极片与包装袋中的金属层发生短路，并且短路位置位于电芯的最外圈极片，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高电芯的安全性。相较于现有技术中最外圈设置双层空箔区的保护结构，在提高电芯安全性的同时减少一层空箔区的使用，进而提高电芯能量密度。
本申请的一些实施例中，沿电极组件的厚度方向，电极组件包括两个相对设置的第一主平面和第二主平面，最外圈的正极极片包括第一收尾端，第一收尾端设于第一主平面，最外圈的负极极片包括第二收尾端，第二收尾端设于第二主平面。通过第一收尾端与第二收尾端收尾在电芯的异侧面，当第一主平面和/或第二主平面遇到针刺等机械外力滥用时，对应的第一收尾端和/或第二收尾端优先发生短路，以同时提高电芯的第一主平面和第二主平面的安全性。
本申请的一些实施例中，第一收尾端包括第一段及第二段，沿第一收尾 端的卷绕方向，第二段设于第一段的外端；第一段设于第二主平面，第二段绕过电芯的拐角卷绕至第一主平面，第一段对应的正极集流体内圈涂覆正极活性材料层，第二段对应的正极集流体未涂覆正极活性材料层。通过第一段对应的正极集流体内圈涂覆正极活性材料层，以使第一段与其包围的负极极片发挥容量，进而提高电芯的能量密度。相较于正极极片与负极极片之间发生短路，正极集流体和/或负极集流体发生短路相对安全，因此通过第二段对应的正极集流体未涂覆正极活性材料层，使正极集流体在电芯遇到针刺等机械外力滥用时发生短路，进而提高电芯的安全性。
本申请的一些实施例中，第二收尾端对应的负极集流体外圈未涂覆负极活性材料层。通过该设置能够使第二段外圈的负极集流体在电芯遇到针刺等机械外力滥用时发生短路，并且负极集流体绕过电芯的拐角，使电芯的拐角处多了一层正极集流体和负极集流体发生安全短路的机会，进而提高电芯的安全性。
本申请的一些实施例中，电芯还包括第二隔膜，第二隔膜覆盖于第二收尾端的端部。通过该设置能够提高第二收尾端的端部的安全性。
本申请的一些实施例中，还包括：电芯进一步包括设于正极极片的正极极耳。包装袋包括依次层叠的融合层、金属层和防护层，融合层设于金属层的内侧面，用于受热熔融以密封包装袋，且防护层设于金属层的外侧面。包装袋设有密封部，正极极耳电连接金属层且自密封部伸出。通过融合层和密封部提高包装袋封装的密封性。通过防护层提高包装袋的结构强度。当电芯遇到针刺等机械外力滥用时，通过正极极耳电连接金属层能够使包装袋中的金属层与正极集流体优先发生短路，并且短路位置位于电芯的最外侧的包装袋，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高电芯的安全性。
本申请的一些实施例中，还包括：密封部内的融合层设有通孔，正极极耳通过通孔电连接金属层。其中，电芯还包括供正极极耳穿出的极耳胶层，极耳胶层部分设置在密封部内。通过通孔提高正极极耳与金属层连接的便利性。通过极耳胶层与融合层熔融结合，提高包装袋封装的密封性。
本申请的一些实施例中，还包括：极耳胶层设有与通孔对应的熔融部，熔融部用于与融合层同步熔融，以裸露熔融部内的正极极耳，正极极耳穿过通孔与金属层电连接。通过极耳胶层与融合层熔融结合，以及通过熔融部与融合层同步熔融，提高电芯封装的密封性。通过裸露的正极极耳通过通孔与金属层电连接，使金属层与正极集流体在电芯遇到针刺等机械外力滥用时优先发生短路，进而提高电芯的安全性。
本申请的一些实施例中，还包括：极耳胶层设有与通孔对应的导电部，导电部穿过通孔抵接金属层以电连接金属层。通过极耳胶层与融合层熔融结合，提高电芯封装的密封性。通过导电部穿过通孔抵接金属层，使正极极耳与金属层电连接，以使金属层与正极集流体在电芯遇到针刺等机械外力滥用时优先发生短路，进而提高电芯的安全性。
本申请的一些实施例中，还包括：极耳胶层为导电胶层，极耳胶层与通孔对应的部分穿过通孔抵接金属层以电连接金属层。通过极耳胶层与融合层熔融结合，提高电芯封装的密封性。通过导电胶制成的极耳胶层，能够使正极极耳与金属层电连接，以使金属层与正极集流体在电芯遇到针刺等机械外力滥用时优先发生短路，进而提高电芯的安全性。
本申请的一些实施例中，还包括：电芯还包括导电件，防护层设有裸露出金属层的凹部，导电件的一端电连接凹部处的金属层，导电件的第二端与设置在包装袋外的正极极耳电连接。通过导电件分别电连接正极极耳和金属层，使正极极耳与金属层电连接，以使金属层与正极集流体在电芯遇到针刺等机械外力滥用时优先发生短路，进而提高电芯的安全性。
本申请的实施例提供一种电池，包括壳体，电池还包括上述任一的电芯，电芯设置在壳体内。
本申请的一些实施例中包括的技术效果：当电池中的电芯遇到针刺等机械外力滥用时，最外圈极片中的正极极片和负极极片优先发生短路。例如最外圈极片中的正极极片或负极极片与包装袋中的金属层发生短路，并且短路位置位于电芯的最外圈极片，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高电池的安全性。
本申请的实施例提供一种用电设备，包括上述的电池。
本申请的一些实施例中包括的技术效果：当用电设备中的电池遇到针刺等机械外力滥用时，最外圈极片中的正极极片和负极极片优先发生短路。例如最外圈极片中的正极极片或负极极片与包装袋中的金属层发生短路，并且短路位置位于电芯的最外圈极片，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高用电设备的安全性。
本申请实施例提供的电芯、电池及用电设备中，当电芯遇到针刺等机械外力滥用时，最外圈极片中的正极极片和负极极片优先发生短路。例如最外圈极片中的正极极片或负极极片与包装袋中的金属层发生短路，并且短路位置位于电芯的最外圈极片，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高电芯的安全性。相较于现有技术中最外圈设置双层空箔区的保护结构，在提高电芯安全性的同时减少一层空箔区的使用，进而提高电芯能量密度。
附图说明
图1为本申请一实施例中电芯的第一俯视结构示意图。
图2为本申请一实施例中电芯的第一局部结构放大示意图。
图3为本申请一实施例中电芯的第一侧面结构示意图。
图4为本申请一实施例中电芯中正极极耳与包装袋的连接第一结构示意图。
图5为本申请一实施例中电芯中正极极耳与包装袋的连接第二结构示意图。
图6为本申请一实施例中电芯中正极极耳与包装袋的连接第三结构示意图。
图7为本申请一实施例中电芯中正极极耳与包装袋的连接第四结构示意图。
图8为本申请一实施例中电芯的第二俯视结构示意图。
图9为本申请一实施例中电芯的第二局部结构放大示意图。
图10为本申请一实施例中电芯的第二侧面结构示意图。
图11为本申请一实施例中电芯的第三俯视结构示意图。
图12为本申请一实施例中电芯的第三局部结构放大示意图。
图13为本申请一实施例中电芯的第三侧面结构示意图。
主要元件符号说明
电芯                         100
电极组件                     10
卷绕中心                     10a
最外圈极片                   10b
第一主平面                   11
第二主平面                   12
正极极片                     20
正极集流体                   21
第一表面                     21a
第二表面                     21b
正极活性材料层               22
第一收尾端                   23
第一段                       231
第二段                       232
正极极耳                     24
负极极片                     30
负极集流体                   31
第三表面                     31a
第四表面                     31b
负极活性材料层               32
第二收尾端                   33
负极极耳                     34
第一隔膜                     40
第二隔膜                     45
包装袋                       50
密封部                       50a
金属层                       51
融合层                       52
防护层                       53
通孔                         54
凹部                         55
导电件                       60
套接槽                       61
极耳胶层                     70、70a、70b、70c
熔融部                       71
导电部                       72
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描述，显然，所描述的实施例仅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，当一个组件被认为是“连接”另一个组件，它可以是直接连接到另一个组件或者可能同时存在居中组件。当一个组件被认为是“设于”另一个组件，它可以是直接设置在另一个组件上或者可能同时存在居中组件。本文所使用的术语“顶”、“底”、“上”、“下”、“左”、“右”、“前”、“后”、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例的目的，不是旨在于限制本申请。
本申请的实施例提供一种电芯，包括电极组件和收容电极组件的包装袋。电极组件包括卷绕设置的正极极片、第一隔膜及负极极片。正极极片包括正极集流体和涂覆于正极集流体的正极活性材料层。负极极片包括负极集流体和涂覆于负极集流体的负极活性材料层。从电极组件的卷绕中心指向电极组件外的方向，定义外围无正极极片或负极极片包覆的极片为电极组件的最外圈极片，最外圈极片包括正极极片和负极极片。
本申请的实施例提供一种电池，包括壳体，电池还包括上述任一的电芯，电芯设置在壳体内。
本申请的另一实施例提供一种用电设备，包括上述的电池。
本申请实施例提供的电芯、电池及用电设备中，当电芯遇到针刺等机械外力滥用时，最外圈极片中的正极极片和负极极片优先发生短路。例如最外圈极片中的正极极片或负极极片与包装袋中的金属层发生短路，并且短路位置位于电芯的最外圈极片，而非电芯内部，有利于散热以避免电芯燃烧或爆炸，进而提高电芯的安全性。相较于现有技术中最外圈设置双层空箔区的保护结构，在提高电芯安全性的同时减少一层空箔区的使用，进而提高电芯能量密度。
下面将结合附图对一些实施方式作详细说明。在不冲突的情况下，下述 的实施例及实施例中的特征可以相互组合。
请一并参阅图1、图2及图3，本实施例的电芯100包括电极组件10和收容电极组件10的包装袋50。电极组件10包括卷绕设置的正极极片20和负极极片30，以及设于正极极片20与负极极片30之间的第一隔膜40。正极极片20包括正极集流体21和涂覆于正极集流体21的正极活性材料层22。负极极片30包括负极集流体31和涂覆于负极集流体31的负极活性材料层32。
正极集流体21包括沿正极集流体21厚度方向相对设置的第一表面21a和第二表面21b，第一表面21a和/或第二表面21b用于涂覆正极活性材料层22。第一表面21a朝向卷绕中心10a，第二表面21b背离卷绕中心10a。定义第一表面21a为正极集流体21内圈，第二表面21b为正极集流体21外圈。负极集流体31包括沿负极集流体31厚度方向相对设置的第三表面31a和第四表面31b，第三表面31a和/或第四表面31b用于涂覆负极活性材料层32。第三表面31a朝向卷绕中心10a，第四表面31b背离卷绕中心10a。定义第三表面31a为负极集流体31内圈，第四表面31b为负极集流体31外圈。
请参阅图1，从电极组件10的卷绕中心10a指向电极组件10外的方向，定义外围无正极极片20或负极极片30包覆的极片为电极组件10的最外圈极片10b，最外圈极片10b包括正极极片20和负极极片30。当电芯100遇到针刺等机械外力滥用时，最外圈极片10b中的正极极片20和负极极片30优先发生短路。例如最外圈极片10b中的正极极片20或负极极片30与位于最外圈极片10b内圈的极片发生短路，或者最外圈极片10b中的正极极片20或负极极片30与包装袋50中的金属层发生短路。并且短路位置位于电芯100的最外圈极片10b，而非电芯100内部，有利于散热以避免电芯100燃烧或爆炸，进而提高电芯100的安全性。
相较于现有技术中最外圈设置双层空箔区的保护结构，通过最外圈极片10b包括正极极片20和负极极片30优先发生短路，在提高电芯100安全性的同时减少一层空箔区的使用，进而提高电芯100能量密度。
请参阅图1，在一些实施例中，沿电极组件10的厚度方向，电极组件10包括两个相对设置的第一主平面11和第二主平面12。最外圈的正极极片20包括第一收尾端23，第一收尾端23设于第一主平面11。最外圈的负极极片30包括第二收尾端33，第二收尾端33设于第二主平面12。
通过第一收尾端23收尾于第一主平面11，以及第二收尾端33收尾于第二主平面12，使第一收尾端23与第二收尾端33收尾在电芯100的异侧面。当第一主平面11和/或第二主平面12遇到针刺等机械外力滥用时，对应的第一收尾端23和/或第二收尾端33优先发生短路，以同时提高电芯100的第一主平面11和第二主平面12的安全性。在一些实施例中，第一收尾端23包括第一段231及第二段232。沿第一收尾端23的卷绕方向，第二段232设于第一段231的外端。第一段231设于第二主平面12，第二段232绕过电芯100的拐角卷绕至第一主平面11。第一段231对应的正极集流体21内圈涂覆正 极活性材料层22，以使第一段231与其包围的负极极片30发挥容量，进而提高电芯100的能量密度。
第二段232对应的正极集流体21未涂覆正极活性材料层22。相较于正极极片20与负极极片30之间发生短路，正极集流体21和/或负极集流体31发生短路相对安全，因此通过第二段232对应的正极集流体21未涂覆正极活性材料层22，使正极集流体21在电芯100遇到针刺等机械外力滥用时发生短路。例如第二段232与位于最外圈极片10b内圈的极片发生短路，或者第二段232与包装袋50中的金属层发生短路。并且短路位置位于电芯100的最外圈极片10b，而非电芯100内部，有利于散热以避免电芯100燃烧或爆炸，进而提高电芯100的安全性。
请一并参阅图1及图2，在一些实施例中，第一段231对应的正极集流体21双面均涂覆有正极活性材料层22。第二段232对应的正极集流体21未涂覆正极活性材料层22。
在一些实施例中，第一段231对应的正极集流体21仅内圈涂覆正极活性材料层22(参图7)，并且第一段231的内端(即第一段231远离第二段232的一端)所连接的正极集流体21双面均涂覆有正极活性材料层22。第二段232对应的正极集流体21未涂覆正极活性材料层22。
在一些实施例中，第一段231对应的正极集流体21由双面均涂覆有正极活性材料层22过渡至仅内圈涂覆正极活性材料层22(参图10)，并且内圈涂覆正极活性材料层22的正极集流体21包围电芯100至少半圈。第二段232对应的正极集流体21未涂覆正极活性材料层22。
在一些实施例中，第二段232占用至第一主平面11面积范围大于0％并小于等于100％。具体在一些实施例中，第二段232占用至第一主平面11面积为10％、20％、30％、40％、50％、60％、70％、80％、90％等中的一种。
请继续参阅图1，第二收尾端33对应的负极集流体31外圈未涂覆负极活性材料层32，以使第二段232外圈的负极集流体31在电芯100遇到针刺等机械外力滥用时发生短路，进而提高电芯100的安全性。并且被第二段232包围的负极极片30对应的负极集流体31绕过电芯100的拐角，使电芯100的拐角处多了一层正极集流体21和负极集流体31发生安全短路的机会，进而提高电芯100的安全性。
可以理解的是，正极极片20中外圈涂覆正极活性材料层22的正极集流体21，外部均有负极极片30包围，并且该负极极片30对应的负极集流体31内圈涂覆负极活性材料层32，使涂覆正极活性材料层22的正极集流体21与包围其的负极极片30发挥容量，进而提高电芯100的能量密度。
请一并参阅图1及图2，在一些实施例中，第二收尾端33对应的负极集流体31仅内圈涂覆负极活性材料层32，并且包围第一收尾端23对应的双面均涂覆正极活性材料层22的正极集流体21至少一圈。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。
在一些实施例中，第二收尾端33对应的负极集流体31双面均未涂覆负 极活性材料层32，并且包围第一收尾端23对应的单面均涂覆正极活性材料层22的正极集流体21至少一圈(参图7)。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。
在一些实施例中，第二收尾端33对应的负极集流体31由内圈涂覆有负极活性材料层32过渡至双面均未涂覆负极活性材料层32，并且双面均未涂覆负极活性材料层32的负极集流体31包围第一收尾端23对应的单面均涂覆正极活性材料层22的正极集流体21至少半圈(参图10)。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。
请一并参阅图1及图2，在一些实施例中，电芯100还包括第二隔膜45，第二隔膜45覆盖于第二收尾端33的端部，用于提高第二收尾端33的端部的安全性。第二收尾端33的端部即最外圈的负极极片30的裁切面所在部位。具体在一些实施例中，第二隔膜45同时包覆第二收尾端33的端部，以及第一段231位于第二主平面12的端部。
请参阅图3，电芯100进一步包括设于正极极片20的正极极耳24，以及设于负极极片30的负极极耳34。包装袋50包括依次层叠的融合层52、金属层51和防护层53。融合层52设于金属层51的内侧面，用于受热熔融以密封包装袋50。防护层53设于金属层51的外侧面，用于提高包装袋50的结构强度，避免包装袋50破坏导致电极组件10受损。
包装袋50设有密封部50a，正极极耳24电连接金属层51且自密封部50a伸出，以提高包装袋50封装的密封性。具体地，密封部50a由融合层52、金属层51和防护层53沿极耳伸出的方向延伸而成。
通过正极极耳24电连接金属层51，在电芯100遇到针刺等机械外力滥用时，包装袋50中的金属层51与正极集流体21优先发生短路，并且短路位置位于电芯100的最外侧的包装袋50，而非电芯100内部，有利于散热以避免电芯100燃烧或爆炸，进而提高电芯100的安全性。
在一些实施例中，包装袋50还包括粘接层，粘接层设置于融合层52与金属层51之间，以及金属层51与防护层53之间，用于提高融合层52、金属层51和防护层53之间的连接稳定性，提高包装袋50的结构强度。
在一些实施例中，金属层51为铝或不锈钢中的一种，融合层52为聚乙烯塑料；防护层53为尼龙或涤纶树脂中的一种。
请参阅图4，密封部50a内的融合层52设有通孔54，正极极耳24通过通孔54电连接金属层51。并且，电芯100还包括供正极极耳24穿出的极耳胶层70，极耳胶层70部分设置在密封部50a内，用于进一步提高包装袋50封装的密封性。
在不同的实施例中，极耳胶层70的结构也有所不同，为区别不同实施例中的极耳胶层70，定义不同实施例中的极耳胶层70分别为极耳胶层70a、极耳胶层70b和极耳胶层70c。
请继续参阅图4，在一些实施例中，极耳胶层70a包覆于正极极耳24位于密封部50a内的部分。极耳胶层70a设有与通孔54对应的熔融部71，熔 融部71用于与融合层52同步熔融，以裸露熔融部71内的正极极耳24，正极极耳24穿过通孔54与金属层51电连接。
上述电芯100中，通过极耳胶层70a与融合层52熔融结合，以及通过在极耳胶层70a上设置熔融部71，使熔融部71与融合层52同步熔融，提高电芯100封装的密封性。通过裸露的正极极耳24通过通孔54与金属层51电连接，使金属层51与正极集流体21在电芯100遇到针刺等机械外力滥用时优先发生短路，进而提高电芯100的安全性。
请参阅图5，在一些实施例中，极耳胶层70b包覆于正极极耳24位于密封部50a内的部分。极耳胶层70b设有与通孔54对应的导电部72，导电部72穿过通孔54抵接金属层51，正极极耳24通过导电部72与金属层51电连接。
上述电芯100中，通过极耳胶层70b与融合层52熔融结合，提高电芯100封装的密封性。通过在极耳胶层70b上设置导电部72，导电部72穿过通孔54抵接金属层51，使正极极耳24与金属层51电连接，以使金属层51与正极集流体21在电芯100遇到针刺等机械外力滥用时优先发生短路，进而提高电芯100的安全性。
请参阅图6，在一些实施例中，极耳胶层70c包覆于正极极耳24位于密封部50a内的部分。极耳胶层70c为导电胶层，极耳胶层70c与通孔54对应的部分穿过通孔54抵接金属层51以电连接金属层51。
上述电芯100中，通过极耳胶层70c与融合层52熔融结合，提高电芯100封装的密封性。通过极耳胶层70c与通孔54对应部分穿过通孔54抵接金属层51，导电胶制成的极耳胶层70c能够使正极极耳24与金属层51电连接，以使金属层51与正极集流体21在电芯100遇到针刺等机械外力滥用时优先发生短路，进而提高电芯100的安全性。
请参阅图7，在一些实施例中，电芯100还包括导电件60。防护层53设有裸露出金属层51的凹部55。导电件60的第一端电连接凹部55处的金属层51，导电件60的第二端与设置在包装袋50外的正极极耳24电连接。
具体在一些实施例中，导电件60朝向密封部50a的一侧设有套接槽61，导电件60通过套接槽61套接于密封部50a的端部。导电件60的中心位置(即导电件60的第二端)供正极极耳24穿过，以使导电件60与正极极耳24电连接。导电件60的周侧(即导电件60的第一端)穿过凹部55与密封部50a中的金属层51抵接，以使导电件60与金属层51电连接。
上述电芯100中，导电件60通过套接槽61套接于密封部50a的端部，提高电芯100封装的密封性。通过导电件60分别电连接正极极耳24和金属层51，使正极极耳24与金属层51电连接，以使金属层51与正极集流体21在电芯100遇到针刺等机械外力滥用时优先发生短路，进而提高电芯100的安全性。
本申请实施例还提供了一种电池(未示出)，包括壳体(未示出)和设置在壳体内的电芯100，电芯100可以为上述实施例中的任意一种电芯。
在一些实施方式中，电池还包括电路保护板(未示出)，电路保护板用于监测电芯100中的电压、电流、绝缘状态及荷电状态等，对电池充电及放电过程进行安全管理，对可能出现的故障进行报警和应急保护处理，对电池的运行进行安全和优化控制。
本申请实施例还提供了一种用电设备(未示出)，包括上述实施例中的任意一种电池。
下面通过具体实施方式说明本发明：
第一实施例：
请一并参阅图1、图2及图3，本实施例的第一收尾端23收尾于第一主平面11，第二收尾端33收尾于第二主平面12。第一段231对应的正极集流体21双面均涂覆有正极活性材料层22。第二段232对应的正极集流体21未涂覆正极活性材料层22。第二段232占用至第一主平面11面积范围大于0％并小于等于100％。第二收尾端33对应的负极集流体31仅内圈涂覆负极活性材料层32，并且包围第一收尾端23对应的双面均涂覆正极活性材料层22的正极集流体21至少一圈。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。第二隔膜45覆盖于第二收尾端33的端部。
第二实施例：
请一并参阅图8、图9及图10，本实施例的第一收尾端23收尾于第一主平面11，第二收尾端33收尾于第二主平面12。第一段231对应的正极集流体21仅内圈涂覆正极活性材料层22，并且第一段231的内端所连接的正极集流体21双面均涂覆有正极活性材料层22。第二段232对应的正极集流体21未涂覆正极活性材料层22。第二段232占用至第一主平面11面积范围大于0％并小于等于100％。第二收尾端33对应的负极集流体31双面均未涂覆负极活性材料层32，并且包围第一收尾端23对应的单面均涂覆正极活性材料层22的正极集流体21至少一圈。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。第二隔膜45覆盖于第二收尾端33的端部。
第三实施例：
请一并参阅图11、图12及图13，本实施例的第一收尾端23收尾于第一主平面11，第二收尾端33收尾于第二主平面12。第一段231对应的正极集流体21由双面均涂覆有正极活性材料层22过渡至仅内圈涂覆正极活性材料层22(参图7)，并且内圈涂覆正极活性材料层22的正极集流体21包围电芯100至少半圈。第二段232对应的正极集流体21未涂覆正极活性材料层22。第二段232占用至第一主平面11面积范围大于0％并小于等于100％。第二收尾端33对应的负极集流体31由内圈涂覆有负极活性材料层32过渡至双面均未涂覆负极活性材料层32，并且双面均未涂覆负极活性材料层32的负极集流体31包围第一收尾端23对应的单面均涂覆正极活性材料层22的正极集流体21至少半圈。第二收尾端33的内端所连接的负极集流体31双面均涂覆有负极活性材料层32。第二隔膜45覆盖于第二收尾端33的端部。
另外，本技术领域的普通技术人员应当认识到，以上的实施例仅是用来说明本申请，而并非用作为对本申请的限定，只要在本申请的实质精神范围之内，对以上实施例所作的适当改变和变化都落在本申请公开的范围之内。

Claims (13)

  1. 一种电芯，包括电极组件和收容所述电极组件的包装袋，所述电极组件包括卷绕设置的正极极片、第一隔膜及负极极片，所述正极极片包括正极集流体和涂覆于所述正极集流体的正极活性材料层，所述负极极片包括负极集流体和涂覆于所述负极集流体的负极活性材料层，其特征在于，从所述电极组件的卷绕中心指向所述电极组件外的方向，定义外围无所述正极极片或所述负极极片包覆的极片为所述电极组件的最外圈极片，所述最外圈极片包括正极极片和负极极片。
  2. 如权利要求1所述的电芯，其特征在于：沿所述电极组件的厚度方向，所述电极组件包括两个相对设置的第一主平面和第二主平面，最外圈的所述正极极片包括第一收尾端，所述第一收尾端设于所述第一主平面，最外圈的所述负极极片包括第二收尾端，所述第二收尾端设于所述第二主平面。
  3. 如权利要求2所述的电芯，其特征在于：所述第一收尾端包括第一段及第二段，沿所述第一收尾端的卷绕方向，所述第二段设于所述第一段的外端；
    所述第一段设于所述第二主平面，所述第二段绕过所述电芯的拐角卷绕至所述第一主平面，所述第一段对应的正极集流体内圈涂覆所述正极活性材料层，所述第二段对应的正极集流体未涂覆所述正极活性材料层。
  4. 如权利要求2所述的电芯，其特征在于：所述第二收尾端对应的负极集流体外圈未涂覆所述负极活性材料层。
  5. 如权利要求2所述的电芯，其特征在于：所述电芯还包括第二隔膜，所述第二隔膜覆盖于所述第二收尾端的端部。
  6. 如权利要求1所述的电芯，其特征在于：所述电芯进一步包括设于所述正极极片的正极极耳；
    所述包装袋包括依次层叠的融合层、金属层和防护层，所述融合层设于所述金属层的内侧面，用于受热熔融以密封所述包装袋，且所述防护层设于所述金属层的外侧面；
    所述包装袋设有密封部，所述正极极耳电连接所述金属层且自所述密封部伸出。
  7. 如权利要求6所述的电芯，其特征在于：所述密封部内的融合层设有通孔，所述正极极耳通过所述通孔电连接所述金属层；
    其中，所述电芯还包括供所述正极极耳穿出的极耳胶层，所述极耳胶层部分设置在所述密封部内。
  8. 如权利要求7所述的电芯，其特征在于：所述极耳胶层设有与所述通孔对应的熔融部，所述熔融部用于与所述融合层同步熔融，以裸露所述熔融部内的正极极耳，所述正极极耳穿过所述通孔与所述金属层电连接。
  9. 如权利要求7所述的电芯，其特征在于：所述极耳胶层设有与所述通孔对应的导电部，所述导电部穿过所述通孔抵接所述金属层以电连接所述金 属层。
  10. 如权利要求7所述的电芯，其特征在于：所述极耳胶层为导电胶层，所述极耳胶层与所述通孔对应的部分穿过所述通孔抵接所述金属层以电连接所述金属层。
  11. 如权利要求6所述的电芯，其特征在于：所述电芯还包括导电件，所述防护层设有裸露出所述金属层的凹部，所述导电件的一端电连接所述凹部处的所述金属层，所述导电件的第二端与设置在所述包装袋外的所述正极极耳电连接。
  12. 一种电池，包括壳体，其特征在于：所述电池还包括如权利要求1至11中任一所述的电芯，所述电芯设置在所述壳体内。
  13. 一种用电设备，其特征在于：包括权利要求12所述的电池。
PCT/CN2021/118150 2021-09-14 2021-09-14 电芯、电池及用电设备 WO2023039706A1 (zh)

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