WO2024082448A1 - 电极组件、电池单体、电池及用电装置 - Google Patents

电极组件、电池单体、电池及用电装置 Download PDF

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Publication number
WO2024082448A1
WO2024082448A1 PCT/CN2022/143534 CN2022143534W WO2024082448A1 WO 2024082448 A1 WO2024082448 A1 WO 2024082448A1 CN 2022143534 W CN2022143534 W CN 2022143534W WO 2024082448 A1 WO2024082448 A1 WO 2024082448A1
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WIPO (PCT)
Prior art keywords
current collector
porous current
electrode assembly
insulating layer
extension section
Prior art date
Application number
PCT/CN2022/143534
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English (en)
French (fr)
Inventor
王慢慢
王毅恒
葛销明
范玉磊
Original Assignee
宁德时代新能源科技股份有限公司
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Publication of WO2024082448A1 publication Critical patent/WO2024082448A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • 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
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • 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
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
    • H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
    • H01M50/213—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for cells having curved cross-section, e.g. round or elliptic
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • 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
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • 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
    • H01M50/593—Spacers; Insulating plates
    • 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

Definitions

  • the present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery and an electrical device.
  • the embodiments of the present application provide an electrode assembly, a battery cell, a battery, and an electrical device, which can effectively improve the safety of the battery cell.
  • an embodiment of the present application provides a battery cell, comprising a positive electrode plate, a negative electrode plate and an insulating layer; the positive electrode plate comprises a coating layer; the negative electrode plate comprises a porous current collector and a first electrode tab connected to at least one end of the porous current collector, wherein the porous current collector and the coating layer are arranged facing each other along the thickness direction of the porous current collector, and the porous current collector has an extension section extending beyond the coating layer along a first direction, and the first direction is perpendicular to the thickness direction of the porous current collector; the insulating layer is arranged corresponding to the extension section, and the projection of the insulating layer on the porous current collector covers part or all of the extension section along the thickness direction of the porous current collector.
  • the negative electrode plate of the electrode assembly is provided with a porous current collector and a first electrode ear protruding from at least one end of the porous current collector.
  • the porous current collector of the negative electrode plate is arranged facing the coating layer of the positive electrode plate in the thickness direction of the porous current collector, and the porous current collector is arranged in the first direction to extend out of the coating layer, that is, the porous current collector covers the coating layer, thereby effectively alleviating the risk of lithium plating during the use of the electrode assembly.
  • an insulating layer is correspondingly provided on the extended section of the porous current collector beyond the coating layer, that is, an insulating layer is correspondingly provided in the area where the porous current collector is not constrained by the expansion force of the coating layer of the positive electrode plate, and the projection of the insulating layer in the thickness direction of the porous current collector covers part or all of the extended section, so that the insulating layer can play a certain blocking role on the lithium ions precipitated on the coating layer, and can effectively reduce the lithium ions entering the extended section of the porous current collector, so as to alleviate the growth of lithium metal dendrites caused by the deposition of lithium metal in the extended section of the porous current collector, and the insulating layer can play a certain blocking role on the lithium metal dendrites formed on the extended section, so as to alleviate the phenomenon of lithium metal dendrites piercing the isolation membrane, and then can effectively alleviate the phenomenon of short circuit between the negative electrode plate and the positive electrode plate due to lithium metal dendrites, so as
  • the projection of the insulating layer completely covers the extension segment.
  • the insulating layer is projected in the thickness direction of the porous current collector to cover the entire extended section of the porous current collector, so that the extended section of the porous current collector beyond the coating layer is correspondingly covered with the insulating layer, thereby effectively improving the insulating layer's blocking effect on lithium ions, further reducing the lithium ions entering the extended section of the porous current collector, thereby alleviating the phenomenon of lithium ions entering the extended section of the porous current collector for deposition, and improving the insulating layer's blocking effect on lithium metal dendrites in the extended section, thereby further alleviating the phenomenon of lithium metal dendrites deposited in the extended section piercing the isolation membrane, thereby further reducing the risk of short-circuiting the positive electrode sheet and the negative electrode sheet, thereby improving the safety of the electrode assembly.
  • the insulating layer does not overlap with the coating layer.
  • the insulating layer so as not to overlap with the coating layer of the positive electrode plate, that is, the insulating layer only covers the area of the porous current collector extending out of the coating layer in the first direction, and the insulating layer does not extend between the coating layer and the porous current collector, the phenomenon of reduced capacity of the electrode assembly due to excessive coverage of the porous current collector by the insulating layer can be alleviated, which is beneficial to ensuring the capacitance and performance of the electrode assembly.
  • the insulating layer is disposed on a side of the extension section facing the coating layer.
  • the insulating layer is arranged on the side of the extension section facing the coating layer so that the insulating layer covers the extension section of the porous current collector.
  • the electrode assembly of this structure enables the insulating layer to block the lithium ions released from the coating layer while better blocking the lithium metal dendrites deposited in the extension section, thereby reducing the risk of the isolation membrane being punctured by the lithium metal dendrites deposited in the extension section, thereby alleviating the short circuit between the positive electrode plate and the negative electrode plate caused by the lithium metal dendrites, thereby improving the safety of the electrode assembly.
  • the insulating layer is connected to a surface of the extending section facing the coating layer.
  • the electrode assembly of this structure can ensure the coverage effect of the insulating layer on the extended section of the porous current collector, so as to reduce the phenomenon of poor coverage caused by the misalignment of the insulating layer and the extended section, thereby improving the effect of the insulating layer in blocking the lithium ions detached from the coating layer from entering the extended section of the porous current collector, so as to inhibit the growth of lithium metal dendrites in the extended section, and can have a better barrier effect on the lithium metal dendrites deposited in the extended section, so as to reduce the risk of the isolation membrane being punctured by lithium metal dendrites.
  • the electrode assembly further includes an isolation membrane; the isolation membrane is disposed between the negative electrode sheet and the positive electrode sheet to separate the negative electrode sheet from the positive electrode sheet; wherein the insulating layer is connected to a surface of the isolation membrane facing the extension section.
  • an isolation membrane is provided between the positive electrode plate and the negative electrode plate, and an insulating layer is connected to the isolation membrane so that the insulating layer covers the extended section of the porous current collector.
  • the electrode assembly of this structure is easy to implement and can effectively reduce the difficulty of assembling the insulating layer.
  • the strength of the isolation membrane can be further improved through the insulating layer to alleviate the phenomenon that the lithium metal dendrites deposited in the extended section pierce the isolation membrane, thereby helping to reduce the short circuit risk of the electrode assembly.
  • the insulating layer is disposed on both sides of the extension section in the thickness direction of the porous current collector.
  • an insulating layer is provided on both sides of the extension section along the thickness direction of the porous current collector, so that the insulating layer can cover both sides of the extension section in the thickness direction of the porous current collector, so that on the one hand, lithium ions can be blocked from both sides of the extension section to reduce the phenomenon of lithium ions entering the extension section for deposition, and on the other hand, lithium metal dendrites deposited in the extension section can be blocked from both sides of the extension section to further alleviate the risk of the isolation membrane being punctured by lithium metal dendrites, thereby further improving the safety of the electrode assembly.
  • the thickness of the insulating layer is D 1 , satisfying 1 ⁇ m ⁇ D 1 ⁇ 10 ⁇ m.
  • the thickness of the insulating layer on one side of the extension section in the thickness direction of the porous current collector to 1 ⁇ m to 10 ⁇ m, on the one hand, it can alleviate the phenomenon that the insulating layer has poor effect in blocking lithium ions and blocking lithium metal dendrites due to the insulating layer being too thin, and can alleviate the problem of greater manufacturing difficulty due to the insulating layer being too thin.
  • it can alleviate the phenomenon that the gap between the coating layer and the porous current collector is too large due to the insulating layer being too thick, thereby effectively alleviating the phenomenon of excessive internal resistance of the electrode assembly and lithium deposition.
  • the insulating layer covers at least a portion of the metal surface of the extension segment.
  • the electrode assembly adopting this structure can have a better barrier effect on lithium ions through the insulating layer, so as to alleviate the phenomenon of lithium ions depositing after contacting the metal of the extension section, thereby reducing the phenomenon of lithium metal dendrite growth in the extension section, so as to further reduce the risk of short circuit between the positive electrode plate and the negative electrode plate.
  • the extension segment has a first surface facing the coating layer, and along the thickness direction of the porous current collector, the insulating layer extends from the first surface toward the interior of the extension segment.
  • the insulating layer with this structure can cover the metal on the first surface of the extension segment to inhibit the deposition of lithium metal after the first surface of the extension segment contacts lithium ions, and can play a certain barrier role on the lithium metal dendrites deposited inside the extension segment, thereby further improving the safety of the electrode assembly.
  • the extension section has the first surface on both sides of the porous current collector in the thickness direction, and the extension section is provided with two insulating layers, and the two insulating layers extend from the two first surfaces to the inside of the extension section respectively.
  • insulating layers are provided on the two first surfaces of the extension section in the thickness direction of the porous current collector, and the two insulating layers extend from the two first surfaces to the inside of the extension section respectively, so that the insulating layer can cover both sides of the extension section in the thickness direction of the porous current collector.
  • it can inhibit the phenomenon of lithium metal deposition after the two first surfaces of the extension section contact with lithium ions, so as to alleviate the growth of lithium metal dendrites on the two first surfaces of the extension section in the thickness direction of the porous current collector.
  • the extension section can block the lithium metal dendrites deposited inside the extension section from both sides of the extension section, so as to further alleviate the risk of the isolation membrane being punctured by the lithium metal dendrites, thereby further improving the safety of the electrode assembly.
  • the extension depth of the insulating layer is D 2
  • the thickness of the extension section is D 3
  • 1 ⁇ m ⁇ D 2 ⁇ D 3 /2 is satisfied.
  • the depth of the insulating layer filled in the extension section is 1 ⁇ m to half of the filled extension section.
  • This can, on the one hand, alleviate the phenomenon that the lithium metal dendrites deposited in the extension section are very easy to grow and exceed the first surface due to the small extension depth of the insulating layer, and can alleviate the problem of greater manufacturing difficulty due to the small extension depth of the insulating layer.
  • it can alleviate the phenomenon that the insulating layers set on both sides of the extension section interfere with each other due to the large extension depth of the insulating layer, and can reduce the waste of the insulating layer.
  • both ends of the porous current collector have the extension segments, and each of the extension segments is correspondingly provided with the insulating layer.
  • extension sections are formed at both ends of the porous current collector in the first direction, that is, both ends of the porous current collector in the first direction exceed the coating layer, so as to ensure the covering effect of the porous current collector on the coating layer in the thickness direction of the porous current collector on the one hand, so as to further alleviate the lithium deposition phenomenon of the electrode assembly; on the other hand, insulating layers are provided on the extension sections exceeding the coating layer at both ends of the porous current collector to play a certain covering role on both ends of the porous current collector, so as to alleviate the phenomenon of lithium metal dendrites depositing at both ends of the porous current collector.
  • the elastic modulus of the insulating layer is E, satisfying E ⁇ 1 GPa.
  • an insulating layer with an elastic modulus greater than or equal to 1 GPa is used, so that the insulating layer has good strength and toughness.
  • it can effectively reduce the phenomenon of damage to the insulating layer during use to improve the service life of the electrode assembly.
  • it can play a good blocking role on lithium metal dendrites, which is beneficial to reduce the phenomenon of the insulating layer being punctured by lithium metal dendrites, thereby effectively reducing the risk of using battery cells.
  • the insulating layer is an insulating tape or an insulating coating.
  • an insulating tape or an insulating coating is used as an insulating layer to cover the extended section of the porous current collector.
  • the insulating layer of this structure only needs to be bonded or coated on the extended section of the porous current collector, which is convenient for assembling the electrode assembly and is beneficial to improving the production efficiency of the electrode assembly.
  • the maximum thickness of the first electrode tab is less than the thickness of the porous current collector.
  • the maximum thickness of the first pole ear in the thickness direction of the porous current collector is smaller than the thickness of the porous current collector, on the one hand, it is convenient to subsequently assemble and connect the first pole ear with other components, and on the other hand, during the production process of the electrode assembly, when the porous current collector of the negative electrode plate is set to have an extension section exceeding the coating layer in the first direction, it is convenient to effectively distinguish the porous current collector and the first pole ear, so as to improve the manufacturing accuracy of the electrode assembly.
  • the porous current collector and the first pole ear are an integrated structure, and the first pole ear is connected to the end of the extension segment in the first direction away from the coating layer; wherein the first pole ear includes a main section and a transition section, along the first direction, the transition section is connected between the main section and the extension section, and the thickness of the transition section in the thickness direction of the porous current collector gradually increases from one end close to the main section to one end close to the extension section.
  • the porous current collector and the first pole ear are arranged as an integrally formed structure, so that the first pole ear is formed with a main section and a transition section connected between the main section and the extension section of the porous current collector, and the thickness of the transition section in the thickness direction of the porous current collector gradually increases from one end close to the main section to one end close to the extension section of the porous current collector, so that the first pole ear protrudes from one end of the porous current collector.
  • the negative electrode plate with such a structure can effectively improve the structural strength of the first pole ear, and can effectively improve the connection strength between the first pole ear and the porous current collector.
  • the porous current collector and the first pole ear are split structures, the first pole ear is connected to one side of the extension section in the thickness direction of the porous current collector, and along the first direction, the first pole ear protrudes from one end of the extension section away from the coating layer.
  • the porous current collector and the first pole ear are arranged as a split structure, and the first pole ear is connected to one side of the extension section of the porous current collector in the thickness direction of the porous current collector and then protrudes from one end of the extension section away from the coating layer along the first direction, so as to realize that the first pole ear protrudes from one end of the porous current collector.
  • the manufacturing difficulty of the negative electrode plate of this structure is relatively low, which is conducive to improving the production efficiency of the electrode assembly.
  • the electrode assembly is a wound electrode assembly, and the first direction is consistent with the winding axis direction of the electrode assembly.
  • the electrode assembly with this structure is easy to manufacture and produce, which is beneficial to reduce the misalignment of the positive electrode sheet and the negative electrode sheet.
  • the porous current collector is made of foam metal.
  • the porous current collector made of foam metal is used so that the porous current collector has the function of directly reacting with lithium ions to realize the input or output of electrical energy of the negative electrode plate, and the porous current collector with this structure can realize the deposition of lithium ions inside the porous current collector, which is beneficial to reduce the risk of lithium metal deposition on the surface of the porous current collector.
  • an embodiment of the present application further provides a battery cell, comprising a housing and the above-mentioned electrode assembly; the electrode assembly is accommodated in the housing.
  • an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.
  • an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell.
  • FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.
  • FIG2 is an exploded view of a battery structure provided in some embodiments of the present application.
  • FIG3 is an exploded view of the structure of a battery cell provided in some embodiments of the present application.
  • FIG4 is a cross-sectional view of an electrode assembly provided in some embodiments of the present application.
  • FIG5 is a partial cross-sectional view of an electrode assembly provided in some embodiments of the present application.
  • FIG6 is a partial enlarged view of the electrode assembly at A shown in FIG5 ;
  • FIG. 7 is a cross-sectional view of a positive electrode sheet of an electrode assembly provided in some embodiments of the present application in other embodiments;
  • FIG8 is a cross-sectional view of a negative electrode sheet of an electrode assembly provided in some embodiments of the present application.
  • FIG9 is a partial cross-sectional view of an electrode assembly provided in some other embodiments of the present application.
  • FIG10 is a partial enlarged view of the electrode assembly at B shown in FIG9;
  • FIG11 is a cross-sectional view of a negative electrode sheet of an electrode assembly provided in some other embodiments of the present application.
  • FIG12 is a cross-sectional view of a negative electrode sheet of an electrode assembly provided in some other embodiments of the present application.
  • FIG13 is a partial cross-sectional view of an electrode assembly provided in some other embodiments of the present application.
  • FIG14 is a partial enlarged view of the electrode assembly at C shown in FIG13;
  • FIG15 is a partial cross-sectional view of an electrode assembly provided in some other embodiments of the present application.
  • FIG16 is a partial enlarged view of a portion D of the electrode assembly shown in FIG15 ;
  • FIG17 is a partial cross-sectional view of an electrode assembly provided in yet other embodiments of the present application.
  • FIG. 18 is a partial enlarged view of the portion E of the electrode assembly shown in FIG. 17 .
  • Icon 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing; 211-shell; 2111-opening; 212-end cover; 22-electrode assembly; 221-negative electrode plate; 2211-porous current collector; 2211a-extension section; 2211b-first surface; 2212-first pole ear; 2212a-main section; 2212b-transition section; 2213-weld stamp; 222-separation film; 223-positive electrode plate; 2231-coating layer; 2231a-positive electrode active material layer; 2231b-insulating protective layer; 2232-substrate; 2232a-second pole ear; 224-insulating layer; 200-controller; 300-motor; X-first direction; Y-thickness direction of porous current collector.
  • the terms “installed”, “connected”, “connected”, and “attached” should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • installed should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • a and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone.
  • the character "/" in this application generally indicates that the associated objects before and after are in an "or" relationship.
  • battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this.
  • Battery cells may be cylindrical, flat, rectangular, or in other shapes, etc., and the embodiments of the present application do not limit this.
  • Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of the present application do not limit this.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in the present application may include a battery module or a battery pack.
  • the battery generally includes a box for encapsulating one or more battery cells or multiple battery modules. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes a shell, an electrode assembly and an electrolyte, and the shell is used to contain the electrode assembly and the electrolyte.
  • the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator.
  • the battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work.
  • the positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode collector, and the part of the positive electrode collector that is not coated with the positive electrode active material layer is used as a positive electrode ear to realize the input or output of the electric energy of the positive electrode sheet through the positive electrode ear.
  • the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.
  • the negative electrode sheet can include a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode collector, and the part of the negative electrode collector that is not coated with the negative electrode active material layer is used as a negative electrode ear to realize the input or output of the electric energy of the negative electrode sheet through the negative electrode ear.
  • the negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon.
  • the negative electrode sheet may also be made of foam metal, and the foam metal may be rolled to form the negative electrode tab or the negative electrode tab may be welded to the foam metal.
  • the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together.
  • the material of the isolation film may be polypropylene (PP) or polyethylene (PE), etc.
  • the electrode assembly may be a winding structure or a stacked structure, but the embodiments of the present application are not limited thereto.
  • Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today.
  • the battery cell is assembled into an electrode assembly (bare cell) by winding or stacking the positive electrode sheet, the negative electrode sheet, and the isolation membrane, which is then loaded into a shell and finally injected with electrolyte.
  • higher requirements are also put forward for the performance and safety of battery use. Therefore, the safety performance of the battery cell determines the safety of the battery during use.
  • foam metal is used as the negative electrode sheet of the electrode assembly, and the width of the negative electrode sheet is set to be greater than the positive electrode sheet, so that the risk of lithium precipitation of the electrode assembly can be reduced while the lithium metal can be deposited inside the negative electrode sheet.
  • the inventors have designed an electrode assembly after in-depth research, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet and an insulating layer.
  • the positive electrode sheet includes a coating layer.
  • the negative electrode sheet includes a porous current collector and a first pole ear connected to at least one end of the porous current collector.
  • the porous current collector and the coating layer are arranged facing each other.
  • the porous current collector has an extension section that exceeds the coating layer, and the first direction is perpendicular to the thickness direction of the porous current collector.
  • the insulating layer is arranged corresponding to the extension section, and along the thickness direction of the porous current collector, the projection of the insulating layer on the porous current collector covers part or all of the extension section.
  • the negative electrode plate of the electrode assembly is provided with a porous current collector and a first electrode ear protruding from at least one end of the porous current collector.
  • an insulating layer is correspondingly provided on the extended section of the porous current collector beyond the coating layer, that is, an insulating layer is correspondingly provided in the area where the porous current collector is not constrained by the expansion force of the coating layer of the positive electrode plate, and the projection of the insulating layer in the thickness direction of the porous current collector covers part or all of the extended section, so that the insulating layer can play a certain blocking role on the lithium ions precipitated on the coating layer, and can effectively reduce the lithium ions entering the extended section of the porous current collector, so as to alleviate the growth of lithium metal dendrites caused by the deposition of lithium metal in the extended section of the porous current collector, and the insulating layer can play a certain blocking role on the lithium metal dendrites formed on the extended section, so as to alleviate the phenomenon of lithium metal dendrites piercing the isolation membrane, and then can effectively alleviate the phenomenon of short circuit between the negative electrode plate and the positive electrode plate due to lithium metal dendrites, so as
  • the electrode assembly disclosed in the embodiment of the present application can be used, but not limited to, in electrical devices such as vehicles, ships or aircraft.
  • a power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device, so that the risk of short circuit of the electrode assembly during later use can be effectively reduced, thereby improving the safety of the battery cells.
  • the embodiment of the present application provides an electric device using a battery as a power source
  • the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc.
  • the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc.
  • the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.
  • FIG. 1 is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • a battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000.
  • the battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000.
  • the vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and driving power requirements of the vehicle 1000.
  • the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.
  • FIG. 2 is an exploded view of the structure of the battery 100 provided in some embodiments of the present application.
  • the battery 100 includes a box body 10 and a battery cell 20, and the battery cell 20 is used to be accommodated in the box body 10.
  • the box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures.
  • the box body 10 may include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20.
  • the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure.
  • the first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.
  • the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.
  • the battery 100 there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection.
  • a mixed connection means that the multiple battery cells 20 are both connected in series and in parallel.
  • the multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10.
  • the battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.
  • Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.
  • the battery cell 20 may be cylindrical, flat, rectangular or in other shapes. For example, in FIG2 , the battery cell 20 is a cylindrical structure.
  • Figure 3 is a structural explosion diagram of a battery cell 20 provided in some embodiments of the present application
  • Figure 4 is a cross-sectional view of an electrode assembly 22 provided in some embodiments of the present application.
  • the battery cell 20 includes a housing 21 and an electrode assembly 22, and the housing 21 is used to accommodate the electrode assembly 22.
  • the housing 21 can also be used to contain electrolyte, such as electrolyte.
  • the housing 21 can be in various structural forms.
  • the housing 21 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the housing 21 may include a shell 211 and an end cap 212, wherein the shell 211 is a hollow structure with an opening 2111 on one side, and the end cap 212 covers the opening 2111 of the shell 211 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the electrode assembly 22 When assembling the battery cell 20 , the electrode assembly 22 may be placed in the housing 211 first, and the housing 211 may be filled with electrolyte, and then the end cap 212 may be closed on the opening 2111 of the housing 211 .
  • the shell 211 can be in various shapes, such as a cylinder, a cuboid, etc.
  • the shape of the shell 211 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a cylindrical shell can be selected; if the electrode assembly 22 is a cuboid structure, a cuboid shell can be selected.
  • the end cap 212 can also be in various structures, such as the end cap 212 being a plate-like structure, a hollow structure with an opening 2111 at one end, etc.
  • the electrode assembly 22 is a cylindrical structure, and correspondingly, the shell 211 is a cylindrical structure, the end cap 212 is a cylindrical plate-like structure, and the end cap 212 covers the opening 2111 of the shell 211.
  • the battery cell 20 may also include a positive electrode terminal and a negative electrode terminal, the positive electrode terminal is mounted on the end cap 212, and the negative electrode terminal is mounted on the end of the housing 211 opposite to the end cap 212.
  • the positive electrode terminal may be mounted on the end of the housing 211 opposite to the end cap 212, and the negative electrode terminal may be mounted on the end cap 212. Both the positive electrode terminal and the negative electrode terminal are used to electrically connect to the electrode assembly 22 to achieve the input or output of electrical energy of the battery cell 20.
  • the positive electrode terminal and the negative electrode terminal may be directly connected to the electrode assembly 22, such as welding or abutting, etc., and the positive electrode terminal and the negative electrode terminal may also be indirectly connected to the electrode assembly 22, such as abutting or welding the positive electrode terminal and the negative electrode terminal to the electrode assembly 22 through a current collecting member.
  • the outer shell 21 is not limited to the above structure, and the outer shell 21 may also be other structures.
  • the outer shell 21 includes a shell body 211 and two end caps 212.
  • the shell body 211 is a hollow structure with openings 2111 on opposite sides.
  • One end cap 212 corresponds to an opening 2111 of the shell body 211 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the battery cell 20 may further include a pressure relief mechanism, which is mounted on the end cover 212 or the housing 211.
  • the pressure relief mechanism is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.
  • the pressure relief mechanism may be a component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve.
  • the electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs.
  • the electrode assembly 22 may include a negative electrode sheet 221, a separator 222, and a positive electrode sheet 223.
  • the electrode assembly 22 may be a wound structure formed by winding the negative electrode sheet 221, the separator 222, and the positive electrode sheet 223, or a laminated structure formed by stacking the negative electrode sheet 221, the separator 222, and the positive electrode sheet 223. Exemplary.
  • the electrode assembly 22 is a wound structure formed by winding the negative electrode sheet 221, the separator 222, and the positive electrode sheet 223.
  • FIG. 5 is a partial cross-sectional view of an electrode assembly 22 provided in some embodiments of the present application
  • FIG. 6 is a partial enlarged view of the electrode assembly 22 at A shown in FIG. 5.
  • the present application provides an electrode assembly 22, and the electrode assembly 22 includes a positive electrode sheet 223, a negative electrode sheet 221, and an insulating layer 224.
  • the positive electrode sheet 223 includes a coating layer 2231.
  • the negative electrode sheet 221 includes a porous current collector 2211 and a first electrode ear 2212 connected to at least one end of the porous current collector 2211.
  • the porous current collector 2211 and the coating layer 2231 are arranged facing each other.
  • the porous current collector 2211 has an extension section 2211a that exceeds the coating layer 2231, and the first direction X is perpendicular to the thickness direction Y of the porous current collector.
  • the insulating layer 224 is disposed corresponding to the extension section 2211 a , and along the thickness direction Y of the porous current collector, the projection of the insulating layer 224 on the porous current collector 2211 covers part or all of the extension section 2211 a .
  • the positive electrode sheet 223 further includes a substrate 2232, and along the thickness direction Y of the porous current collector, the coating layer 2231 is disposed on at least one side of the substrate 2232, and along the first direction X, the portion of the substrate 2232 that exceeds the coating layer 2231 forms a second pole ear 2232a, which serves as the positive output electrode of the electrode assembly 22, and is used to be connected to the positive electrode terminal to realize the input or output of electrical energy of the electrode assembly 22.
  • the coating layer 2231 is disposed on both sides of the substrate 2232.
  • the material of the substrate 2232 can be various, for example, copper, iron, aluminum, steel, aluminum alloy, etc.
  • the coating layer 2231 includes a positive electrode active material layer 2231a, and the positive electrode active material layer 2231a and the porous current collector 2211 of the negative electrode plate 221 are the areas where chemical reactions occur in the battery cell 20, and mainly rely on the movement of metal ions between the positive electrode active material layer 2231a and the porous current collector 2211 to work.
  • FIG7 is a cross-sectional view of the positive electrode plate 223 of the electrode assembly 22 provided in some embodiments of the present application in other embodiments, the coating layer 2231 may also include an insulating protective layer 2231b, which is arranged at at least one end of the positive electrode active material layer 2231a along the first direction X to protect and separate the positive electrode active material layer 2231a, and the material of the insulating protective layer 2231b may be plastic, rubber or silicone.
  • the coating layer 2231 includes two insulating protective layers 2231b, which are respectively located at both ends of the positive electrode active material layer 2231a in the first direction X and connected to the positive electrode active material layer 2231a.
  • the insulating protective layer 2231b may not be provided at one end of the positive electrode active material layer 2231a in the first direction X, that is, the coating layer 2231 includes only the positive electrode active material layer 2231a.
  • the material of the positive electrode active material layer 2231a can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide.
  • the porous current collector 2211 of the negative electrode plate 221 is a structure having multiple pores, which may be foam metal or a mesh structure woven from metal wires.
  • the first pole tab 2212 is connected to at least one end of the porous current collector 2211, that is, the first pole tab 2212 is connected to at least one end of the porous current collector 2211 in the thickness direction Y perpendicular to the porous current collector.
  • the first pole tab 2212 may be connected to one end of the porous current collector 2211, or both ends of the porous current collector 2211 may be connected to the first pole tab 2212.
  • the first pole tab 2212 serves as the negative output pole of the electrode assembly 22.
  • the first pole tab 2212 is used to be connected to the negative electrode terminal to realize the input or output of electrical energy of the electrode assembly 22.
  • the first pole ear 2212 is connected to one end of the porous current collector 2211 in the first direction X, that is, the first pole ear 2212 is connected to one end of the extension segment 2211a of the porous current collector 2211 in the first direction X away from the coating layer 2231.
  • the first pole ear 2212 may also be connected to one end of the porous current collector 2211 in a direction Y perpendicular to the first direction X and the thickness of the porous current collector. It should be noted that the first pole ear 2212 is connected to one end of the porous current collector 2211 in the first direction X.
  • the first pole ear 2212 can be connected to one end of the porous current collector 2211 in the first direction X, or it can be connected to the side of the porous current collector 2211 facing the coating layer 2231 in the thickness direction Y of the porous current collector. It is only necessary for the first pole ear 2212 to extend along the first direction X and protrude from one end of the porous current collector 2211 in the first direction X. In other words, the first pole ear 2212 can be connected to one end of the extension section 2211a in the first direction X away from the coating layer 2231, or it can be connected to the side of the extension section 2211a in the thickness direction Y of the porous current collector facing the coating layer 2231. It is only necessary for the first pole ear 2212 to extend along the first direction X and protrude from one end of the extension section 2211a in the first direction X away from the coating layer 2231.
  • the electrode assembly 22 is a winding structure
  • the thickness direction Y of the porous current collector is the radial direction of the electrode assembly 22
  • the first direction X is the width direction of the negative electrode sheet 221, and is also the extension direction of the winding center axis of the electrode assembly 22.
  • the first direction X can also be the winding direction of the electrode assembly 22, that is, the first direction X is the extension direction of the negative electrode sheet 221.
  • the first direction X is the extension direction of the negative electrode sheet 221
  • the first direction X and the thickness direction Y of the porous current collector are perpendicular to each other, which means that the tangent of the point where the first direction X intersects with the thickness direction Y of the porous current collector in the first direction X is perpendicular to the thickness direction Y of the porous current collector.
  • the electrode assembly 22 is a laminated structure, that is, the negative electrode sheet 221 and the positive electrode sheet 223 are alternately stacked along the thickness direction Y of the porous current collector
  • the first direction X can be the width direction of the negative electrode sheet 221, or the length direction of the negative electrode sheet 221.
  • the porous current collector 2211 and the coating layer 2231 are arranged facing each other, that is, the negative electrode plate 221 and the positive electrode plate 223 are stacked in the thickness direction Y of the porous current collector, so that the coating layer 2231 arranged on one side of the substrate 2232 can be arranged facing the porous current collector 2211.
  • the porous current collector 2211 has an extension section 2211a that exceeds the coating layer 2231, that is, the porous current collector 2211 has a portion extending out of the coating layer 2231 in the first direction X, and the portion is the extension section 2211a.
  • both ends of the porous current collector 2211 extend out of the coating layer 2231, that is, both ends of the porous current collector 2211 in the first direction X are formed with extension sections 2211a.
  • the insulating layer 224 is arranged corresponding to the extension section 2211a.
  • the projection of the insulating layer 224 on the porous current collector 2211 covers part or all of the extension section 2211a, that is, in the thickness direction Y of the porous current collector, the insulating layer 224 can cover at least part of the extension section 2211a, that is, in the thickness direction Y of the porous current collector, the projection of the insulating layer 224 on the porous current collector 2211 can cover part of the extension section 2211a, or can cover all of the extension section 2211a.
  • the insulating layer 224 can be assembled in a variety of ways, for example, the insulating layer 224 can be connected to the extension section 2211a of the porous current collector 2211, or can be connected to the isolation film 222 located between the positive electrode sheet 223 and the negative electrode sheet 221.
  • the insulating layer 224 may be disposed on the surface of the extension section 2211a facing the coating layer 2231, or may be disposed inside the extension section 2211a, that is, the insulating layer 224 fills the extension section 2211a.
  • the negative electrode plate 221 of the electrode assembly 22 is provided with a porous current collector 2211 and a first electrode ear 2212 protruding from at least one end of the porous current collector 2211.
  • the porous current collector 2211 of the negative electrode plate 221 is arranged facing the coating layer 2231 of the positive electrode plate 223 in the thickness direction Y of the porous current collector, and the porous current collector 2211 is arranged in the first direction X to extend out of the coating layer 2231, that is, the porous current collector 2211 covers the facing coating layer 2231, thereby effectively alleviating the risk of lithium deposition in the electrode assembly 22 during use.
  • an insulating layer 224 is correspondingly provided on the extension section 2211a of the porous current collector 2211 beyond the coating layer 2231, that is, an insulating layer 224 is correspondingly provided in the area where the porous current collector 2211 is not bound by the expansion force of the coating layer 2231 of the positive electrode sheet 223, and the projection of the insulating layer 224 in the thickness direction Y of the porous current collector covers part or all of the extension section 2211a, so that the insulating layer 224 can play a certain blocking role on the lithium ions precipitated on the coating layer 2231, which can effectively reduce the lithium ions entering the porous current collector.
  • the lithium ions in the extension section 2211a of the porous current collector 2211 can alleviate the growth of lithium metal dendrites caused by the deposition of lithium metal in the extension section 2211a of the porous current collector 2211, and the insulating layer 224 can play a certain barrier role on the lithium metal dendrites formed on the extension section 2211a, so as to alleviate the phenomenon of lithium metal dendrites piercing the isolation membrane 222, and further can effectively alleviate the short circuit between the negative electrode plate 221 and the positive electrode plate 223 due to lithium metal dendrites, so as to reduce the safety hazard of the electrode assembly 22 during use.
  • the projection of the insulating layer 224 completely covers the extension section 2211 a .
  • the projection of the insulating layer 224 completely covers the extension section 2211a, that is, in the thickness direction Y of the porous current collector, the insulating layer 224 can cover the entire extension section 2211a of the porous current collector 2211, that is, the area of the porous current collector 2211 that exceeds the coating layer 2231 of the positive electrode sheet 223 in the first direction X is covered by the insulating layer 224.
  • the extension section 2211a of the porous current collector 2211 beyond the coating layer 2231 is correspondingly covered with the insulating layer 224, thereby effectively improving the blocking effect of the insulating layer 224 on lithium ions, so as to further reduce the lithium ions entering the extension section 2211a of the porous current collector 2211, thereby alleviating the phenomenon of lithium ions entering the extension section 2211a of the porous current collector 2211 for deposition, and improving the blocking effect of the insulating layer 224 on lithium metal dendrites in the extension section 2211a, so as to further alleviate the phenomenon of lithium metal dendrites deposited in the extension section 2211a piercing the isolation membrane 222, thereby further reducing the risk of short circuit between the positive electrode plate 223 and the negative electrode plate 221, so as to improve the safety of the electrode assembly 22.
  • the insulating layer 224 and the coating layer 2231 do not overlap.
  • the insulating layer 224 does not overlap with the coating layer 2231, that is, the insulating layer 224 does not extend between the coating layer 2231 and the porous current collector 2211 in the thickness direction Y of the porous current collector, that is, the insulating layer 224 only covers the area of the porous current collector 2211 extending out of the coating layer 2231 in the first direction X.
  • the phenomenon of reduced capacity of the electrode assembly 22 caused by the insulating layer 224 covering too much area of the porous current collector 2211 can be alleviated, which is beneficial to ensuring the capacitance and performance of the electrode assembly 22.
  • Figure 8 is a cross-sectional view of the negative electrode sheet 221 of the electrode assembly 22 provided in some embodiments of the present application.
  • an insulating layer 224 is provided on one side of the extension section 2211a facing the coating layer 2231.
  • the insulating layer 224 is disposed on the side of the extension section 2211a facing the coating layer 2231, that is, the insulating layer 224 is located between the extension section 2211a and the isolation film 222 in the thickness direction Y of the porous current collector.
  • the insulating layer 224 can be connected to the extension section 2211a or to the isolation film 222.
  • the insulating layer 224 By arranging the insulating layer 224 on the side of the extension section 2211a facing the coating layer 2231, the insulating layer 224 covers the extension section 2211a of the porous current collector 2211.
  • the electrode assembly 22 of this structure enables the insulating layer 224 to block the lithium ions released from the coating layer 2231 while better blocking the lithium metal dendrites deposited in the extension section 2211a, thereby reducing the risk of the isolation membrane 222 being punctured by the lithium metal dendrites deposited in the extension section 2211a, thereby alleviating the short circuit between the positive electrode plate 223 and the negative electrode plate 221 caused by the lithium metal dendrites, thereby improving the safety of the electrode assembly 22.
  • the insulating layer 224 is connected to the surface of the extension section 2211 a facing the coating layer 2231 .
  • the insulating layer 224 can be connected to the surface of the extension section 2211 a by bonding or adsorption.
  • the electrode assembly 22 of this structure can ensure the coverage effect of the insulating layer 224 on the extension section 2211a of the porous current collector 2211, so as to reduce the phenomenon that the insulating layer 224 and the extension section 2211a are misaligned and cause poor coverage, thereby improving the effect of the insulating layer 224 in blocking the lithium ions released from the coating layer 2231 from entering the extension section 2211a of the porous current collector 2211, so as to inhibit the growth of lithium metal dendrites in the extension section 2211a, and can have a better barrier effect on the lithium metal dendrites deposited in the extension section 2211a, so as to reduce the risk of the isolation membrane 222 being punctured by lithium metal dendrites.
  • the electrode assembly 22 further includes a separator 222.
  • the separator 222 is disposed between the negative electrode sheet 221 and the positive electrode sheet 223 to separate the negative electrode sheet 221 from the positive electrode sheet 223.
  • the insulating layer 224 is connected to the surface of the separator 222 facing the extension section 2211a.
  • the insulating layer 224 can be connected to the surface of the isolation film 222 facing the extension section 2211a by bonding or adsorption.
  • the material of the isolation film 222 may be polypropylene (PP) or polyethylene (PE).
  • the electrode assembly 22 of this structure is easy to implement and can effectively reduce the difficulty of assembling the insulating layer 224.
  • the strength of the isolation membrane 222 can be further improved through the insulating layer 224 to alleviate the phenomenon that the lithium metal dendrites deposited in the extension section 2211a pierce the isolation membrane 222, thereby helping to reduce the short circuit risk of the electrode assembly 22.
  • an insulating layer 224 is provided on both sides of the extension section 2211a in the thickness direction Y of the porous current collector.
  • the extension section 2211a is provided with an insulating layer 224 on both sides of the thickness direction Y of the porous current collector. That is to say, in the thickness direction Y of the porous current collector, an insulating layer 224 is arranged between the extension section 2211a and the two adjacent isolation membranes 222.
  • the insulating layer 224 can cover both sides of the extension section 2211a in the thickness direction Y of the porous current collector, so that on the one hand, lithium ions can be blocked from both sides of the extension section 2211a to reduce the phenomenon of lithium ions entering the extension section 2211a for deposition, and on the other hand, lithium metal dendrites deposited in the extension section 2211a can be blocked from both sides of the extension section 2211a to further alleviate the risk of the isolation film 222 being punctured by lithium metal dendrites, thereby further improving the safety of the electrode assembly 22.
  • the thickness of the insulating layer 224 is D 1 , satisfying 1 ⁇ m ⁇ D 1 ⁇ 10 ⁇ m.
  • the thickness D1 of the insulating layer 224 may be 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 5 ⁇ m, 8 ⁇ m, or 10 ⁇ m.
  • the thickness of the insulating layer 224 on one side of the extension section 2211a in the thickness direction Y of the porous current collector is 1 ⁇ m to 10 ⁇ m, on the one hand, the phenomenon that the insulating layer 224 has a poor effect in blocking lithium ions and blocking lithium metal dendrites due to the insulating layer 224 being too thin can be alleviated, and the problem of greater manufacturing difficulty due to the insulating layer 224 being too thin can be alleviated.
  • the phenomenon that the gap between the coating layer 2231 and the porous current collector 2211 is too large due to the insulating layer 224 being too thick can be alleviated, thereby effectively alleviating the phenomenon of excessive internal resistance of the electrode assembly 22 and lithium deposition.
  • Figure 9 is a partial cross-sectional view of an electrode assembly 22 provided in some other embodiments of the present application
  • Figure 10 is a partial enlarged view of the electrode assembly 22 at B shown in Figure 9.
  • the insulating layer 224 covers at least a portion of the metal surface of the extension section 2211a.
  • the insulating layer 224 covers at least a portion of the metal surface of the extension section 2211 a , that is, the insulating layer 224 is filled in the extension section 2211 a , so that the insulating layer 224 can cover the metal in the extension section 2211 a .
  • the insulating layer 224 may cover part of the metal of the extension section 2211 a or cover all of the metal of the extension section 2211 a .
  • the electrode assembly 22 with such a structure can have a better barrier effect on lithium ions through the insulating layer 224, so as to alleviate the phenomenon of lithium ions depositing after contacting the metal of the extension section 2211a, thereby reducing the phenomenon of lithium metal dendrite growth in the extension section 2211a, so as to further reduce the risk of short circuit between the positive electrode plate 223 and the negative electrode plate 221.
  • Figures 9 and 10 are cross-sectional views of the negative electrode sheet 221 of the electrode assembly 22 provided in some other embodiments of the present application.
  • the extension section 2211a has a first surface 2211b facing the coating layer 2231, and along the thickness direction Y of the porous current collector, the insulating layer 224 extends from the first surface 2211b to the inside of the extension section 2211a.
  • the insulating layer 224 extends from the first surface 2211b to the interior of the extension section 2211a, that is, the insulating layer 224 preferentially covers the metal on the surface of the extension section 2211a facing the coating layer 2231, and then extends from the surface of the extension section 2211a facing the coating layer 2231 to the interior of the extension section 2211a to cover the metal inside the extension section 2211a.
  • the insulating layer 224 By setting the insulating layer 224 to a structure extending from the first surface 2211b of the extension section 2211a to the interior of the extension section 2211a, the insulating layer 224 with this structure can cover the metal of the first surface 2211b of the extension section 2211a to inhibit the deposition of lithium metal after the first surface 2211b of the extension section 2211a contacts lithium ions, and can play a certain blocking role on the lithium metal dendrites deposited inside the extension section 2211a, thereby further improving the safety of the electrode assembly 22.
  • the extension section 2211a has a first surface 2211b on both sides of the porous current collector in the thickness direction Y, and the extension section 2211a is provided with two insulating layers 224, and the two insulating layers 224 extend from the two first surfaces 2211b to the interior of the extension section 2211a respectively.
  • the two insulating layers 224 extend from the two first surfaces 2211b to the interior of the extension section 2211a respectively, that is, in the thickness direction Y of the porous current collector, the surfaces on both sides of the extension section 2211a are provided with insulating layers 224, and the two insulating layers 224 extend from the surfaces on both sides of the extension section 2211a to the interior of the extension section 2211a respectively.
  • the insulating layers 224 disposed on the two first surfaces 2211b of the extension section 2211a both extend from the first surface 2211b to the inside of the extension section 2211a, and there is a gap between the two insulating layers 224 in the thickness direction Y of the porous current collector, that is, the two insulating layers 224 cooperate to cover part of the metal of the extension section 2211a.
  • FIG12 is a cross-sectional view of the negative electrode sheet 221 of the electrode assembly 22 provided in some other embodiments of the present application in other embodiments, the two insulating layers 224 extend from the two first surfaces 2211b of the extension section 2211a to the inside of the extension section 2211a, respectively, and the two insulating layers 224 are connected to each other, that is, the two insulating layers 224 cooperate to cover all the metal of the extension section 2211a.
  • the insulating layer 224 can cover the two sides of the extension section 2211a in the thickness direction Y of the porous current collector, so as to, on the one hand, suppress the phenomenon of lithium metal deposition after the two first surfaces 2211b of the extension section 2211a contact with lithium ions, so as to alleviate the growth of lithium metal dendrites on the two first surfaces 2211b of the extension section 2211a in the thickness direction Y of the porous current collector, and on the other hand, block the lithium metal dendrites deposited inside the extension section 2211a from both sides of the extension section 2211a, so as to further alleviate the risk of the isolation film 222 being punctured by the lithium metal dendrites, thereby further improving the safety of the electrode assembly 22.
  • the extension depth of the insulating layer 224 is D 2
  • the thickness of the extension section 2211 a is D 3 , satisfying 1 ⁇ m ⁇ D 2 ⁇ D 3 /2.
  • the depth of the insulating layer 224 filled in the extension section 2211a is 1 ⁇ m to fill half of the extension section 2211a.
  • the extension depth of the insulating layer 224 in the extension section 2211a is 1 ⁇ m to half the thickness of the extension section 2211a, on the one hand, the phenomenon that the lithium metal dendrites deposited in the extension section 2211a are very easy to grow and exceed the first surface 2211b due to the small extension depth of the insulating layer 224 can be alleviated, and the problem of greater manufacturing difficulty caused by the small extension depth of the insulating layer 224 can be alleviated.
  • the phenomenon that the insulating layers 224 set on both sides of the extension section 2211a interfere with each other due to the large extension depth of the insulating layer 224 can be alleviated, and the waste of the insulating layer 224 can be reduced.
  • both ends of the porous current collector 2211 have extension segments 2211 a , and each extension segment 2211 a is correspondingly provided with an insulating layer 224 .
  • the two ends of the porous current collector 2211 both have extension sections 2211 a , that is, in the first direction X, the two ends of the porous current collector 2211 both extend beyond the coating layer 2231 of the positive electrode sheet 223 .
  • Extension sections 2211a are formed at both ends of the porous current collector 2211 in the first direction X, that is, both ends of the porous current collector 2211 in the first direction X exceed the coating layer 2231, so that on the one hand, the covering effect of the porous current collector 2211 on the coating layer 2231 in the thickness direction Y of the porous current collector can be ensured to further alleviate the lithium deposition phenomenon of the electrode assembly 22; on the other hand, an insulating layer 224 is provided on the extension sections 2211a exceeding the coating layer 2231 at both ends of the porous current collector 2211, so as to play a certain covering role on both ends of the porous current collector 2211, so as to alleviate the phenomenon of lithium metal dendrites being deposited at both ends of the porous current collector 2211.
  • the elastic modulus of the insulating layer 224 is E, which satisfies E ⁇ 1 GPa.
  • the value of the elastic modulus of the insulating layer 224 can be found in national standards and will not be described in detail here.
  • An insulating layer 224 with an elastic modulus greater than or equal to 1 GPa is used, so that the insulating layer 224 has better strength and toughness. On the one hand, it can effectively reduce the phenomenon of damage to the insulating layer 224 during use, so as to improve the service life of the electrode assembly 22. On the other hand, it can play a better blocking role on lithium metal dendrites, which is beneficial to reduce the phenomenon of the insulating layer 224 being punctured by lithium metal dendrites, thereby effectively reducing the risk of using the battery cell 20.
  • the insulating layer 224 is an insulating tape or an insulating coating.
  • the insulating layer 224 is an insulating tape
  • the insulating layer 224 can be a blue tape or a green tape, etc.
  • the insulating layer 224 is connected to the extension section 2211a of the porous current collector 2211 or the isolation membrane 222 by bonding
  • the insulating layer 224 is an insulating coating
  • the insulating layer 224 can be an epoxy resin insulating paint or an alumina ceramic coating, etc.
  • the insulating layer 224 is connected to the extension section 2211a of the porous current collector 2211 or the isolation membrane 222 by coating, and its elastic modulus can be seen in the table below.
  • the insulating layer 224 may be an insulating tape or an insulating coating, so that the insulating layer 224 can be connected to the surface of the extension section 2211a facing the coating layer 2231 or the surface of the isolation film 222 facing the extension section 2211a by bonding or coating; in the embodiment where the insulating layer 224 covers at least part of the metal surface of the extension section 2211a, the insulating layer 224 may adopt an insulating coating so that the insulating layer 224 can be filled in the extension section 2211a, thereby achieving the coating of at least part of the metal of the extension section 2211a.
  • An insulating tape or insulating coating is used as the insulating layer 224 to cover the extended section 2211a of the porous current collector 2211.
  • the insulating layer 224 of this structure only needs to be bonded or coated on the extended section 2211a of the porous current collector 2211, which is convenient for assembling the electrode assembly 22 and is beneficial to improving the production efficiency of the electrode assembly 22.
  • the maximum thickness of the first electrode tab 2212 is less than the thickness of the porous current collector 2211 .
  • the maximum thickness of the first electrode tab 2212 is smaller than the thickness of the porous current collector 2211 , that is, the thickness of the first electrode tab 2212 at any position in the thickness direction Y of the porous current collector is smaller than the thickness of the porous current collector 2211 .
  • the maximum thickness of the first pole ear 2212 in the thickness direction Y of the porous current collector is smaller than the thickness of the porous current collector 2211, on the one hand, it is convenient to subsequently assemble and connect the first pole ear 2212 with other components.
  • the porous current collector 2211 of the negative electrode plate 221 is set to have an extension section 2211a exceeding the coating layer 2231 in the first direction X, it is convenient to effectively distinguish the porous current collector 2211 and the first pole ear 2212, so as to improve the manufacturing accuracy of the electrode assembly 22.
  • the porous current collector 2211 and the first pole ear 2212 are an integrated structure, and the first pole ear 2212 is connected to one end of the extension section 2211a away from the coating layer 2231 in the first direction X.
  • the first pole ear 2212 includes a main body section 2212a and a transition section 2212b, and along the first direction X, the transition section 2212b is connected between the main body section 2212a and the extension section 2211a, and the thickness of the transition section 2212b in the thickness direction Y of the porous current collector gradually increases from one end close to the main body section 2212a to one end close to the extension section 2211a.
  • the first pole ear 2212 is a structure formed by rolling or other processes at one end of the negative electrode sheet 221 in the first direction X, so that the negative electrode sheet 221 is formed with a porous current collector 2211 and a first pole ear 2212 protruding from one end of the porous current collector 2211 in the first direction X and having a smaller thickness, that is, the first pole ear 2212 is formed with a main section 2212a and a transition section 2212b connected between the main section 2212a and the extension section 2211a of the porous current collector 2211, and the main section 2212a is used to be connected to the negative electrode terminal.
  • the porous current collector 2211 and the first pole ear 2212 are an integrated structure
  • the insulating layer 224 is arranged on the side of the extension section 2211a facing the coating layer 2231, it is only necessary to set the insulating layer 224 to cover the area where the thickness of the porous current collector 2211 is not reduced and exceeds the coating layer 2231 in the first direction X; referring to Figures 9 and 11, if the insulating layer 224 is arranged to cover the surface of at least part of the metal of the extension section 2211a, it is only necessary to fill the insulating layer 224 in the area where the thickness of the porous current collector 2211 is not reduced and exceeds the coating layer 2231 in the first direction X.
  • the first pole ear 2212 is formed with a main section 2212a and a transition section 2212b connected between the main section 2212a and the extension section 2211a of the porous current collector 2211, and the thickness of the transition section 2212b in the thickness direction Y of the porous current collector gradually increases from one end close to the main section 2212a to one end close to the extension section 2211a of the porous current collector 2211, thereby achieving the first pole ear 2212 protruding from one end of the porous current collector 2211.
  • the negative electrode plate 221 with such a structure can effectively improve the structural strength of the first pole ear 2212, and can effectively improve the connection strength between the first pole ear 2212 and the porous current collector 2211.
  • Figure 13 is a partial cross-sectional view of an electrode assembly 22 provided in some other embodiments of the present application
  • Figure 14 is a partial enlarged view of the electrode assembly 22 at C shown in Figure 13
  • Figure 15 is a partial cross-sectional view of the electrode assembly 22 provided in some other embodiments of the present application
  • Figure 16 is a partial enlarged view of the electrode assembly 22 at D shown in Figure 15.
  • the porous current collector 2211 and the first pole ear 2212 are split structures, the first pole ear 2212 is connected to one side of the extension section 2211a in the thickness direction Y of the porous current collector, and along the first direction X, the first pole ear 2212 protrudes from the end of the extension section 2211a away from the coating layer 2231.
  • the first pole ear 2212 and the porous current collector 2211 are split structures, that is, the first pole ear 2212 and the porous current collector 2211 are independent components, and the first pole ear 2212 is connected to one side of the extension section 2211a of the porous current collector 2211 in the thickness direction Y of the porous current collector and extends out of one end of the porous current collector 2211 along the first direction X.
  • the first pole ear 2212 and the porous current collector 2211 have an overlapping area in the thickness direction Y of the porous current collector, and a portion of the first pole ear 2212 is connected to the porous current collector 2211 and extends out of one end of the porous current collector 2211 along the first direction X.
  • the first electrode tab 2212 is welded to the extension section 2211 a of the porous current collector 2211 to form a weld mark 2213 .
  • the insulating layer 224 is arranged on the side of the extension section 2211a facing the coating layer 2231, the insulating layer 224 needs to be arranged to cover the portion of the porous current collector 2211 that exceeds the coating layer 2231 in the first direction X, and the insulating layer 224 can cover the area where the first pole ear 2212 and the porous current collector 2211 are stacked and connected to form a weld mark 2213; as shown in Figures 15 and 16, if the insulating layer 224 is arranged to cover the surface of at least part of the metal of the extension section 2211a, it is only necessary to set the insulating layer 224 to cover the metal of the portion of the porous current collector 2211 that exceeds the coating layer 2231 in the first direction X, and there is no need to cover the weld mark 2213 formed by welding the first pole ear 2212
  • Figure 17 is a partial cross-sectional view of the electrode assembly 22 provided in some embodiments of the present application
  • Figure 18 is a partial enlarged view of the electrode assembly 22 at E shown in Figure 17.
  • An insulating layer 224 can also be set on the surface of the weld mark 2213 formed by welding the first pole ear 2212 and the extension section 2211a of the porous current collector 2211, so that the insulating layer 224 can also cover the weld mark 2213 formed by welding the first pole ear 2212 and the extension section 2211a of the porous current collector 2211.
  • the manufacturing difficulty of the negative electrode plate 221 of this structure is relatively low, which is conducive to improving the production efficiency of the electrode assembly 22.
  • the electrode assembly 22 is a wound electrode assembly 22
  • the first direction X is consistent with the winding axis direction of the electrode assembly 22 .
  • the electrode assembly 22 is a winding structure, so that the first direction X is the extension direction of the winding axis of the electrode assembly 22, that is, the plane where the winding direction of the electrode assembly 22 is located is perpendicular to the first direction X, and the thickness direction Y of the porous current collector is the radial direction of the electrode assembly 22.
  • the electrode assembly 22 By configuring the electrode assembly 22 to be a winding structure, and the first direction X being consistent with the winding axis direction of the electrode assembly 22 , the electrode assembly 22 with such a structure is easy to manufacture and produce, and is beneficial to reducing the misalignment between the positive electrode sheet 223 and the negative electrode sheet 221 .
  • the porous current collector 2211 is made of foam metal.
  • the material of the porous current collector 2211 is copper foam.
  • the material of the porous current collector 2211 may also be nickel foam, etc.
  • Using copper foam as the material of the porous current collector 2211 can make the porous current collector 2211 have better electrical conductivity, which is conducive to reducing the internal resistance of the electrode assembly 22 having such a negative electrode plate 221, so as to improve the performance of the battery cell 20.
  • the porous current collector 2211 made of foam metal enables the porous current collector 2211 to have the function of directly reacting with lithium ions to realize the input or output of electrical energy of the negative electrode plate 221, and the porous current collector 2211 with this structure can realize the deposition of lithium ions inside the porous current collector 2211, which is beneficial to reduce the risk of lithium metal deposition on the surface of the porous current collector 2211.
  • the embodiments of the present application further provide a battery cell 20 , which includes a housing 21 and an electrode assembly 22 of any of the above schemes, wherein the electrode assembly 22 is accommodated in the housing 21 .
  • a battery 100 is further provided, and the battery 100 includes a battery cell 20 of any of the above schemes.
  • an electric device is further provided.
  • the electric device includes a battery cell 20 according to any of the above schemes, and the battery cell 20 is used to provide electric energy to the electric device.
  • the electrical device may be any of the aforementioned devices or systems using the battery cell 20 .
  • the present application provides an electrode assembly 22, which includes a negative electrode sheet 221, a separator 222, a positive electrode sheet 223, and an insulating layer 224.
  • the separator 222 is disposed between the negative electrode sheet 221 and the positive electrode sheet 223 to separate the negative electrode sheet 221 from the positive electrode sheet 223.
  • the positive electrode sheet 223 includes a substrate 2232 and a coating layer 2231 coated on both sides of the substrate 2232. Along the first direction X, one end of the substrate 2232 extends out of the coating layer 2231 to form a second pole ear 2232a.
  • the negative electrode plate 221 includes a porous current collector 2211 and a first pole tab 2212 connected to one end of the porous current collector 2211 in a first direction X.
  • first direction X Along the thickness direction Y of the porous current collector, the porous current collector 2211 and the coating layer 2231 are arranged facing each other.
  • first direction X both ends of the porous current collector 2211 exceed the coating layer 2231 and form an extension section 2211a.
  • the first direction X is perpendicular to the thickness direction Y of the porous current collector.
  • the porous current collector 2211 and the first pole tab 2212 are an integrated structure.
  • the first pole tab 2212 includes a main section 2212a and a transition section 2212b.
  • the transition section 2212b is connected between the main section 2212a and the extension section 2211a, and the thickness of the transition section 2212b in the thickness direction Y of the porous current collector gradually increases from one end close to the main section 2212a to one end close to the extension section 2211a.
  • An insulating layer 224 is disposed on the side of the extension section 2211a facing the coating layer 2231, and the insulating layer 224 is connected to the surface of the extension section 2211a.
  • the projection of the insulating layer 224 on the porous current collector 2211 completely covers the extension section 2211a, and the insulating layer 224 does not overlap with the coating layer 2231.
  • the thickness of the insulating layer 224 is D 1 , which satisfies 1 ⁇ m ⁇ D 1 ⁇ 10 ⁇ m.

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Abstract

本申请提供了一种电极组件、电池单体、电池及用电装置，属于电池技术领域。其中，电池单体包括正极极片、负极极片和绝缘层。正极极片包括涂覆层。负极极片包括多孔集流体和连接于多孔集流体的至少一端的第一极耳，沿多孔集流体的厚度方向，多孔集流体与涂覆层面向设置，沿第一方向，多孔集流体具有超出涂覆层的延伸段，第一方向垂直于多孔集流体的厚度方向。绝缘层与延伸段对应设置，沿多孔集流体的厚度方向，绝缘层在多孔集流体上的投影覆盖延伸段的部分或全部。通过绝缘层能够对涂覆层脱离的锂离子进行阻挡，以减少锂离子进入延伸段沉积的现象，且能够对延伸段形成的锂金属枝晶进行阻隔，降低隔离膜被刺破的风险，以提升电极组件的使用安全。

Description

电极组件、电池单体、电池及用电装置
相关申请的交叉引用
本申请要求享有于2022年10月21日提交的名称为“电极组件、电池单体、电池及用电装置”的中国专利申请202222788856.2的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域，具体而言，涉及一种电极组件、电池单体、电池及用电装置。
背景技术
近些年，新能源汽车有了飞跃式的发展，在电动汽车领域，动力电池作为电动汽车的动力源，起着不可替代的重要作用。随着新能源汽车的大力推广，对动力电池产品的需求也日益增长，其中，电池作为新能源汽车核心零部件不论在使用寿命或安全性方面等都有着较高的要求。电池的电池单体是由正极极片、负极极片和隔离膜通过卷绕或者叠片等方式组装成电极组件(裸电芯)，之后装入外壳，再注入电解液后得到的。但是，现有技术中的电池单体在后期使用过程中极容易出现短路等安全隐患，从而导致电池单体存在较大的使用风险。
发明内容
本申请实施例提供一种电极组件、电池单体、电池及用电装置，能够有效提高电池单体的安全性。
第一方面，本申请实施例提供一种电池单体，包括正极极片、负极极片和绝缘层；所述正极极片包括涂覆层；所述负极极片包括多孔集流体和连接于所述多孔集流体的至少一端的第一极耳，沿所述多孔集流体的厚度方向，所述多孔集流体与所述涂覆层面向设置，沿第一方向，所述多孔集流体具有超出所述涂覆层的延伸段，所述第一方向垂直于所述多孔集流体的厚度方向；所述绝缘层与所述延伸段对应设置，沿所述多孔集流体的厚度方向，所述绝缘层在所述多孔集流体上的投影覆盖所述延伸段的部分或全部。
在上述技术方案中，电极组件的负极极片设置有多孔集流体和凸设于多孔集流体的至少一端的第一极耳，通过将负极极片的多孔集流体在多孔集流体的厚度方向上与正极极片的涂覆层面向设置，并将多孔集流体在第一方向上设置为延伸出涂覆层，即多孔集流体覆盖面向设置的涂覆层，从而能够有效缓解电极组件在使用过程中出现析锂的风险。此外，通过在多孔集流体超出涂覆层的延伸段上对应设置有绝缘层，即在多孔集流体没有受到正极极片的涂覆层的膨胀力束缚的区域对应设置有绝缘层，且绝缘层在多孔集流体的厚度方向上的投影覆盖延伸段的部分或全部，从而通过绝缘层能够对涂覆层上析出的锂离子起到一定的阻挡作用，能够有效减少进入多孔集流体的延伸段内的锂离子，以缓解因锂金属在多孔集流体的延伸段沉积而出现锂金属枝晶生长的情况，且通过绝缘层能够对延伸段上形成的锂金属枝晶起到一定的阻隔作用，以缓解锂金属枝晶刺破隔离膜的现象，进而能够有效缓解负极极片和正极极片因锂金属枝晶而出现短接的现象，以降低电极组件在使用过程中的安全隐患。
在一些实施例中，沿所述多孔集流体的厚度方向，所述绝缘层的投影完全覆盖所述延伸段。
在上述技术方案中，通过将绝缘层在多孔集流体的厚度方向上投影设置为对多孔集流体的延伸段的整体进行覆盖，使得多孔集流体超出涂覆层的延伸段上均对应覆盖有绝缘层，从而能够有效提升绝缘层对锂离子的阻挡效果，以进一步减少进入多孔集流体的延伸段内的锂离子，从而能够缓解锂离子进入多孔集流体的延伸段内进行沉积的现象，且能够提升绝缘层对延伸段的锂金属枝晶的效阻挡果，以进一步缓解延伸段沉积的锂金属枝晶刺破隔离膜的现象，进而能够进一步降低正极极片和负极极片的短接风险，以提升电极组件的使用安全性。
在一些实施例中，沿所述多孔集流体的厚度方向，所述绝缘层与所述涂覆层不重叠。
在上述技术方案中，通过将绝缘层设置为与正极极片的涂覆层相互不重叠，即绝缘层只对多孔集流体在第一方向上延伸出涂覆层的区域进行了覆盖，而绝缘层未延伸至涂覆层与多孔集流体之间，从而能够缓解因绝缘层覆盖多孔集流体的区域过多而造成电极组件的容量降低的现象，有利于保证电极组件的电容量和使用性能。
在一些实施例中，沿所述多孔集流体的厚度方向，所述延伸段面向所述涂覆层的一侧设置有所述绝缘层。
在上述技术方案中，通过将绝缘层设置于延伸段面向涂覆层的一侧上，以实现绝缘层对多孔集流体的延伸段进行覆盖，这种结构的电极组件使得绝缘层在对涂覆层中脱离出来的锂离子起到阻挡作用的同时能够更好地对延伸段沉积的锂金属枝晶起到阻隔效果，以降低隔离膜被延伸段沉积的锂金属枝晶刺破的风险，从而能够缓解正极极片和负极极片之间因锂金属枝晶而造成的短接现象，以提升电极组件的使用安全性。
在一些实施例中，所述绝缘层连接于所述延伸段面向所述涂覆层的表面。
在上述技术方案中，通过将绝缘层连接于多孔集流体的延伸段面向涂覆层的表面上，这种结构的电极组件能够保证绝缘层对多孔集流体的延伸段的覆盖效果，以降低绝缘层与延伸段发生错位而导致覆盖效果不佳的现象，从而能够提升绝缘层阻挡涂覆层脱离出来的锂离子进入多孔集流体的延伸段内的效果，以抑制延伸段的锂金属枝晶的生长，且能够对延伸段沉积的锂金属枝晶起到较好的阻隔效果，以降低隔离膜被锂金属枝晶刺破的风险。
在一些实施例中，所述电极组件还包括隔离膜；所述隔离膜设置于所述负极极片与所述正极极片之间，以分隔负极极片与所述正极极片；其中，所述绝缘层连接于所述隔离膜面向所述延伸段的表面。
在上述技术方案中，通过在正极极片和负极极片之间设置隔离膜，并将绝缘层连接于隔离膜上，以实现绝缘层对多孔集流体的延伸段进行覆盖，这种结构的电极组件便于实现，能够有效降低绝缘层的装配难度，且通过绝缘层能够进一步提升隔离膜的强度，以缓解延伸段沉积的锂金属枝晶刺破隔离膜的现象，从而有利于降低电极组 件的短路风险。
在一些实施例中，所述延伸段在所述多孔集流体的厚度方向上的两侧均设置有所述绝缘层。
在上述技术方案中，通过在延伸段沿多孔集流体的厚度方向上的两侧均设置绝缘层，使得绝缘层能够对延伸段在多孔集流体的厚度方向上的两侧进行覆盖，从而一方面能够从延伸段的两侧对锂离子进行阻挡，以减少锂离子进入延伸段进行沉积的现象，另一方面能够从延伸段的两侧为延伸段沉积的锂金属枝晶进行阻隔，以进一步缓解隔离膜被锂金属枝晶刺破的风险，进而能够进一步提升电极组件的使用安全性。
在一些实施例中，沿所述多孔集流体的厚度方向，所述绝缘层的厚度为D 1，满足，1μm≤D 1≤10μm。
在上述技术方案中，通过将设置于延伸段在多孔集流体的厚度方向上的一侧绝缘层的厚度设置在1μm到10μm，一方面能够缓解因绝缘层的厚度过小而造成绝缘层阻挡锂离子和阻隔锂金属枝晶的效果较差的现象，且能够缓解因绝缘层的厚度过小而导致制造难度较大的问题，另一方面能够缓解因绝缘层的厚度过大而导致涂覆层与多孔集流体之间的间隙过大的现象，从而能够有效缓解电极组件的内阻过大和析锂的现象。
在一些实施例中，所述绝缘层包覆所述延伸段的至少部分的金属的表面。
在上述技术方案中，通过将绝缘层设置为包覆于延伸段的至少部分的金属的表面上，也就是说，绝缘层填充于延伸段，使得绝缘层能够对延伸段的金属进行包覆，以实现绝缘层对多孔集流体的延伸段进行覆盖，采用这种结构的电极组件通过绝缘层能够对锂离子起到较好的阻隔效果，以缓解锂离子接触延伸段的金属后进行沉积的现象，从而能够减少延伸段出现锂金属枝晶生长的现象，以进一步降低正极极片与负极极片出现短接的风险。
在一些实施例中，所述延伸段具有面向所述涂覆层的第一表面，沿所述多孔集流体的厚度方向，所述绝缘层从所述第一表面向所述延伸段的内部延伸。
在上述技术方案中，通过将绝缘层设置为从延伸段的第一表面向延伸段的内部延伸的结构，采用这种结构绝缘层能够对延伸段的第一表面的金属进行包覆，以抑制延伸段的第一表面接触锂离子后出现锂金属沉积的现象，且能够对延伸段的内部沉积的锂金属枝晶起到一定的阻隔作用，从而能够进一步提升电极组件的使用安全性。
在一些实施例中，所述延伸段在所述多孔集流体的厚度方向上的两侧均具有所述第一表面，且所述延伸段设置有两个所述绝缘层，两个所述绝缘层分别从两个所述第一表面向所述延伸段的内部延伸。
在上述技术方案中，通过在延伸段沿多孔集流体的厚度方向上的两个第一表面上均设置绝缘层，且两个绝缘层分别从两个第一表面想延伸段的内部延伸，使得绝缘层能够对延伸段在多孔集流体的厚度方向上的两侧进行覆盖，从而一方面能够抑制延伸段的两个第一表面接触锂离子后出现锂金属沉积的现象，以缓解延伸段在多孔集流体的厚度方向上的两个第一表面出现锂金属枝晶生长的情况，另一方面能够从延伸段的两侧为延伸段的内部沉积的锂金属枝晶进行阻隔，以进一步缓解隔离膜被锂金属枝晶刺破的风险，进而能够进一步提升电极组件的使用安全性。
在一些实施例中，沿所述多孔集流体的厚度方向，所述绝缘层的延伸深度为D 2，所述延伸段的厚度为D 3，满足，1μm≤D 2≤D 3/2。
在上述技术方案中，通过将绝缘层在延伸段内的延伸深度设置在1μm到延伸段的厚度的一半，也就是说，在多孔集流体的厚度方向上，绝缘层填充于延伸段内的深度为1μm到填充延伸段的一半，从而一方面能够缓解因绝缘层的延伸深度过小而造成延伸段沉积的锂金属枝晶极容易生长并超出第一表面的现象，且能够缓解因绝缘层的延伸深度过小而导致制造难度较大的问题，另一方面能够缓解因绝缘层的延伸深度过大而导致延伸段的两侧设置的绝缘层出现相互干涉的现象，且能够减少绝缘层的浪费。
在一些实施例中，沿所述第一方向，所述多孔集流体的两端均具有所述延伸段，每个所述延伸段均对应设置有所述绝缘层。
在上述技术方案中，多孔集流体在第一方向上的两端均形成有延伸段，即多孔集流体在第一方向上的两端均超出涂覆层，从而一方面能够保证多孔集流体在多孔集流体的厚度方向上对涂覆层的覆盖效果，以进一步缓解电极组件的析锂现象，另一方面通过在多孔集流体的两端超出涂覆层的延伸段上均设置有绝缘层，以对多孔集流体的两端均能够起到一定的覆盖作用，以缓解锂金属枝晶在多孔集流体的两端进行沉积的现象。
在一些实施例中，所述绝缘层的弹性模量为E，满足，E≥1Gpa。
在上述技术方案中，采用弹性模量大于或等于1GPa的绝缘层，使得这种绝缘层具有较好的强度和韧性，一方面能够有效降低绝缘层在使用过程中出现损坏的现象，以提升电极组件的使用寿命，另一方面能够对锂金属枝晶起到较好的阻挡作用，有利于减少绝缘层被锂金属枝晶刺破的现象，从而能够有效降低电池单体的使用风险。
在一些实施例中，所述绝缘层为绝缘胶带或绝缘涂层。
在上述技术方案中，采用绝缘胶带或绝缘涂层作为绝缘层对多孔集流体的延伸段进行覆盖，这种结构的绝缘层只需将绝缘层粘接或涂覆于多孔集流体的延伸段即可，便于对电极组件进行装配，有利于提升电极组件的生产效率。
在一些实施例中，沿所述多孔集流体的厚度方向，所述第一极耳的最大厚度小于所述多孔集流体的厚度。
在上述技术方案中，通过将第一极耳在多孔集流体的厚度方向上的最大厚度设置为小于多孔集流体的厚度，一方面便于后续将第一极耳与其他部件进行装配连接，另一方面在电极组件的生产过程中，在将负极极片的多孔集流体设置为在第一方向上具有超出涂覆层的延伸段时便于对多孔集流体和第一极耳进行有效区分，以提高电极组件的制造精度。
在一些实施例中，所述多孔集流体与所述第一极耳为一体式结构，所述第一极耳连接于所述延伸段在所述第一方向上远离所述涂覆层的一端；其中，所述第一极耳包括主体段和过渡段，沿所述第一方向，所述过渡段连 接于所述主体段和所述延伸段之间，且所述过渡段在所述多孔集流体的厚度方向上的厚度从靠近所述主体段的一端向靠近所述延伸段的一端逐渐增大。
在上述技术方案中，通过将多孔集流体和第一极耳设置为一体成型的结构，使得第一极耳形成有主体段和连接于主体段和多孔集流体的延伸段之间的过渡段，且过渡段在多孔集流体的厚度方向上的厚度从靠近主体段的一端向靠近多孔集流体的延伸段的一端逐渐增大，从而实现第一极耳凸出于多孔集流体的一端，采用这种结构的负极极片能够有效提高第一极耳的结构强度，且能够有效提升第一极耳与多孔集流体之间的连接强度。
在一些实施例中，所述多孔集流体与所述第一极耳为分体式结构，所述第一极耳连接于所述延伸段在所述多孔集流体的厚度方向上的一侧，且沿所述第一方向，所述第一极耳凸出于所述延伸段远离所述涂覆层的一端。
在上述技术方案中，通过将多孔集流体和第一极耳设置为分体式结构，并将第一极耳连接于多孔集流体的延伸段在多孔集流体的厚度方向上的一侧后沿第一方向凸出于延伸段远离涂覆层的一端，以实现第一极耳凸出于多孔集流体的一端，这种结构的负极极片的制造难度较低，有利于提升电极组件的生产效率。
在一些实施例中，所述电极组件为卷绕式电极组件，所述第一方向与所述电极组件的卷绕轴线方向一致。
在上述技术方案中，通过将电极组件设置为卷绕式的结构，且第一方向与电极组件的卷绕轴线方向一致，采用这种结构的电极组件便于制造和生产，有利于降低正极极片和负极极片出现错位的现象。
在一些实施例中，所述多孔集流体的材质为泡沫金属。
在上述技术方案中，采用泡沫金属的多孔集流体使得多孔集流体具有与锂离子直接进行反应的功能，以实现负极极片的电能输入或输出，且这种结构的多孔集流体能够实现锂离子在多孔集流体的内部进行沉积，有利于降低多孔集流体的表面出现锂金属沉积的风险。
第二方面，本申请实施例还提供一种电池单体，包括外壳和上述的电极组件；所述电极组件容纳于所述外壳内。
第三方面，本申请实施例还提供一种电池，包括上述的电池单体。
第四方面，本申请实施例还提供一种用电装置，包括上述的电池单体。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的结构***图；
图3为本申请一些实施例提供的电池单体的结构***图；
图4为本申请一些实施例提供的电极组件的截面图；
图5为本申请一些实施例提供的电极组件的局部剖视图；
图6为图5所示的电极组件的A处的局部放大图；
图7为本申请一些实施例提供的电极组件的正极极片在另一些实施例中的剖视图；
图8为本申请一些实施例提供的电极组件的负极极片的剖视图；
图9为本申请又一些实施例提供的电极组件的局部剖视图；
图10为图9所示的电极组件的B处的局部放大图；
图11为本申请又一些实施例提供的电极组件的负极极片的剖视图；
图12为本申请又一些实施例提供的电极组件的负极极片在另一些实施例中的剖视图；
图13为本申请再一些实施例提供的电极组件的局部剖视图；
图14为图13所示的电极组件的C处的局部放大图；
图15为本申请另一些实施例提供的电极组件的局部剖视图；
图16为图15所示的电极组件的D处的局部放大图；
图17为本申请再又一些实施例提供的电极组件的局部剖视图；
图18为图17所示的电极组件的E处的局部放大图。
图标：1000-车辆；100-电池；10-箱体；11-第一箱本体；12-第二箱本体；20-电池单体；21-外壳；211-壳体；2111-开口；212-端盖；22-电极组件；221-负极极片；2211-多孔集流体；2211a-延伸段；2211b-第一表面；2212-第一极耳；2212a-主体段；2212b-过渡段；2213-焊印；222-隔离膜；223-正极极片；2231-涂覆层；2231a-正极活性物质层；2231b-绝缘保护层；2232-基体；2232a-第二极耳；224-绝缘层；200-控制器；300-马达；X-第一方向；Y-多孔集流体的厚度方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，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地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请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；本申请中在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； 本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请中，电池单体可以包括锂离子二次电池、锂离子一次电池、锂硫电池、钠离子电池或镁离子电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体或多个电池模组的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括外壳、电极组件和电解液，外壳用于容纳电极组件和电解液。电极组件由正极极片、负极极片和隔离膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的正极集流体的部分作为正极极耳，以通过正极极耳实现正极极片的电能输入或输出。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片可以包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的负极集流体的部分作为负极极耳，以通过负极极耳实现负极极片的电能输入或输出。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。当然，负极极片也可以直接采用泡沫金属作为负极极片，并将泡沫金属的部分进行辊压形成负极极耳或将负极极耳焊接于泡沫金属上。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。
隔离膜的材质可以为聚丙烯(polypropylene，PP)或聚乙烯(polyethylene，PE)等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。
电池具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点，是现今新能源发展的重要组成部分。电池的电池单体是由正极极片、负极极片和隔离膜通过卷绕或者叠片等方式组装成电极组件(裸电芯)，之后装入外壳，最后注入电解液后得到的。但是，随着电池技术的不断发展，对电池的使用性能和使用安全等也提出了更高的要求。因此，电池单体的安全性能决定了电池在使用过程中的安全性。
发明人发现，在电池的后期使用过程中，电池单体的电极组件容易产生锂金属沉积的现象，主要表现为在电极组件的负极极片上存在锂金属沉积的问题，从而常常导致负极极片出现表面沉积枝晶等现象，进而极容易造成隔离膜被损坏而出现电极组件短路的风险。为了解决负极极片在锂金属析出时造成的使用安全问题，在采用泡沫金属作为电极组件的负极极片，并将负极极片的宽度设置为大于正极极片，从而在降低电极组件的析锂风险的同时能够实现锂金属在负极极片的内部沉积。但是，在这种结构的电池单体中，由于泡沫金属的负极极片在超出正极极片的部分没有受到膨胀力束缚，且使得整个负极极片受到的压力不均衡，从而极容易出现锂金属枝晶无限生长的情况，使得电极组件存在隔离膜被锂金属枝晶刺破而引起正极极片和负极极片短接的现象，进而造成电池单体在后期使用过程中存在较大的安全隐患，不利于消费者的使用安全。
基于上述考虑，为了解决电池单体在后期使用过程中存在较大的安全隐患的问题，发明人经过深入研究，设计了一种电极组件，电极组件包括正极极片、负极极片和绝缘层。正极极片包括涂覆层。负极极片包括多孔集流体和连接于多孔集流体的至少一端的第一极耳，沿多孔集流体的厚度方向，多孔集流体与涂覆层面向设置，沿第一方向，多孔集流体具有超出涂覆层的延伸段，第一方向垂直于多孔集流体的厚度方向。绝缘层与延伸段对应设置，沿多孔集流体的厚度方向，绝缘层在多孔集流体上的投影覆盖延伸段的部分或全部。
在这种结构的电极组件中，电极组件的负极极片设置有多孔集流体和凸设于多孔集流体的至少一端的第一极耳，通过将负极极片的多孔集流体在多孔集流体的厚度方向上与正极极片的涂覆层面向设置，并将多孔集流体在第一方向上设置为延伸出涂覆层，即多孔集流体覆盖面向设置的涂覆层，从而能够有效缓解电极组件在使用过程中出现析锂的风险。此外，通过在多孔集流体超出涂覆层的延伸段上对应设置有绝缘层，即在多孔集流体没有受到正极极片的涂覆层的膨胀力束缚的区域对应设置有绝缘层，且绝缘层在多孔集流体的厚度方向上的投影覆盖延伸段的部分或全部，从而通过绝缘层能够对涂覆层上析出的锂离子起到一定的阻挡作用，能够有效减少进入多孔集流体的延伸段内的锂离子，以缓解因锂金属在多孔集流体的延伸段沉积而出现锂金属枝晶生长的情况，且通过绝缘层能 够对延伸段上形成的锂金属枝晶起到一定的阻隔作用，以缓解锂金属枝晶刺破隔离膜的现象，进而能够有效缓解负极极片和正极极片因锂金属枝晶而出现短接的现象，以降低电极组件在使用过程中的安全隐患。
本申请实施例公开的电极组件可以但不限用于车辆、船舶或飞行器等用电装置中。可以使用具备本申请公开的电池单体、电池等组成该用电装置的电源***，这样，能够有效降低电极组件在后期使用过程中出现短路的风险，以提升电池单体的使用安全性。
本申请实施例提供一种使用电池作为电源的用电装置，用电装置可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中，电动玩具可以包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
以下实施例为了方便说明，以本申请一实施例的一种用电装置为车辆1000为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的结构***图。电池100包括箱体10和电池单体20，电池单体20用于容纳于箱体10内。其中，箱体10用于为电池单体20提供装配空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一箱本体11和第二箱本体12，第一箱本体11与第二箱本体12相互盖合，第一箱本体11和第二箱本体12共同限定出用于容纳电池单体20的装配空间。第二箱本体12可以为一端开放的空心结构，第一箱本体11可以为板状结构，第一箱本体11盖合于第二箱本体12的开放侧，以使第一箱本体11与第二箱本体12共同限定出装配空间；第一箱本体11和第二箱本体12也可以是均为一侧开放的空心结构，第一箱本体11的开放侧盖合于第二箱本体12的开放侧。当然，第一箱本体11和第二箱本体12形成的箱体10可以是多种形状，比如，圆柱体、长方体等。
在电池100中，电池单体20可以是多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，用于实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池或一次电池；还可以是锂硫电池、钠离子电池或镁离子电池，但不局限于此。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。示例性的，在图2中，电池单体20为圆柱体结构。
请参照图3和图4，图3为本申请一些实施例提供的电池单体20的结构***图，图4为本申请一些实施例提供的电极组件22的截面图。电池单体20包括外壳21和电极组件22，外壳21用于容纳电极组件22。
其中，外壳21还可用于容纳电解质，例如电解液。外壳21可以是多种结构形式。外壳21的材质也可以是多种，比如，铜、铁、铝、钢、铝合金等。
在一些实施例中，外壳21可以包括壳体211和端盖212，壳体211为一侧开口2111的空心结构，端盖212盖合于壳体211的开口2111处并形成密封连接，以形成用于容纳电极组件22和电解质的密封空间。
在组装电池单体20时，可先将电极组件22放入壳体211内，并向壳体211内填充电解质，再将端盖212盖合于壳体211的开口2111。
壳体211可以是多种形状，比如，圆柱体、长方体等。壳体211的形状可根据电极组件22的具体形状来确定。比如，若电极组件22为圆柱体结构，则可选用为圆柱体壳体；若电极组件22为长方体结构，则可选用长方体壳体。当然，端盖212也可以是多种结构，比如，端盖212为板状结构、一端开口2111的空心结构等。示例性的，在图3中，电极组件22为圆柱体结构，对应的，壳体211为圆柱体结构，端盖212为圆柱形板状结构，端盖212盖合于壳体211的开口2111处。
在一些实施例中，电池单体20还可以包括正极电极端子和负极电极端子，正极电极端子安装于端盖212上，负极电极端子安装于壳体211与端盖212相对的一端上，当然，也可以是正极电极端子安装于壳体211与端盖212相对的一端上，负极电极端子安装于端盖212上。正极电极端子和负极电极端子均用于与电极组件22电连接，以实现电池单体20的电能的输入或输出。其中，正极电极端子和负极电极端子可以是与电极组件22直接相连，比如，焊接或抵接等，正极电极端子和负极电极端子也可以是与电极组件22间接相连，比如，正极电极端子和负极电极端子通过集流构件与电极组件22抵接或焊接等。
可理解的，外壳21并不仅仅局限于上述结构，外壳21也可以是其他结构，比如，外壳21包括壳体211和两个端盖212，壳体211为相对的两侧开口2111的空心结构，一个端盖212对应盖合于壳体211的一个开口2111处并形成密封连接，以形成用于容纳电极组件22和电解质的密封空间。
在一些实施例中，电池单体20还可以包括泄压机构，泄压机构安装于端盖212上，也可以安装于壳体211上。泄压机构用于在电池单体20的内部压力或温度达到预定值时泄放电池单体20内部的压力。
示例性的，泄压机构可以是诸如防爆阀、防爆片、气阀、泄压阀或安全阀等部件。
需要说明的是，电极组件22是电池单体20中发生电化学反应的部件。电极组件22可以包括负极极片 221、隔离膜222和正极极片223。电极组件22可以是由负极极片221、隔离膜222和正极极片223通过卷绕形成的卷绕式结构，也可以是由负极极片221、隔离膜222和正极极片223通过层叠布置形成的叠片式结构。示例性的。在图4中，电极组件22为由负极极片221、隔离膜222和正极极片223卷绕形成的卷绕式结构。
根据本申请的一些实施例，参照图4，并请进一步参照图5和图6，图5为本申请一些实施例提供的电极组件22的局部剖视图，图6为图5所示的电极组件22的A处的局部放大图。本申请提供了一种电极组件22，电极组件22包括正极极片223、负极极片221和绝缘层224。正极极片223包括涂覆层2231。负极极片221包括多孔集流体2211和连接于多孔集流体2211的至少一端的第一极耳2212，沿多孔集流体的厚度方向Y，多孔集流体2211与涂覆层2231面向设置，沿第一方向X，多孔集流体2211具有超出涂覆层2231的延伸段2211a，第一方向X垂直于多孔集流体的厚度方向Y。绝缘层224与延伸段2211a对应设置，沿多孔集流体的厚度方向Y，绝缘层224在多孔集流体2211上的投影覆盖延伸段2211a的部分或全部。
其中，正极极片223还包括基体2232，沿多孔集流体的厚度方向Y，涂覆层2231设置于基体2232的至少一侧，沿第一方向X，基体2232超出涂覆层2231的部分形成第二极耳2232a，第二极耳2232a作为电极组件22的正输出极，第二极耳2232a用于与正极电极端子相连，以实现电极组件22的电能的输入或输出。示例性的，在图5中，基体2232的两侧均设置有涂覆层2231。
基体2232的材质可以是多种，比如，铜、铁、铝、钢、铝合金等。
可选地，参见图5所示，涂覆层2231包括正极活性物质层2231a，正极活性物质层2231a和负极极片221的多孔集流体2211是电池单体20内发生化学反应的区域，主要依靠金属离子在正极活性物质层2231a和多孔集流体2211之间移动来工作。当然，在一些实施例中，参照图7，图7为本申请一些实施例提供的电极组件22的正极极片223在另一些实施例中的剖视图，涂覆层2231还可以包括绝缘保护层2231b，沿第一方向X设置于正极活性物质层2231a的至少一端，以对正极活性物质层2231a起到保护和分隔的作用，绝缘保护层2231b的材质可以是塑胶、橡胶或硅胶等。示例性的，在图7中，涂覆层2231包括两个绝缘保护层2231b，两个绝缘保护层2231b分别位于正极活性物质层2231a在第一方向X上的两端，并连接于正极活性物质层2231a。需要说明的是，在一些实施例中，比如，参见图5所示，正极活性物质层2231a在第一方向X上的一端也可以不设置绝缘保护层2231b，即涂覆层2231只包括正极活性物质层2231a。
示例性的，正极活性物质层2231a的材质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。
在一些实施例中，负极极片221的多孔集流体2211为具有多个孔隙的结构，其可以为泡沫金属，也可以为由金属丝编织而成的网状结构。
其中，第一极耳2212连接于多孔集流体2211的至少一端，即第一极耳2212连接于多孔集流体2211在垂直于多孔集流体的厚度方向Y上的至少一端，第一极耳2212可以是连接于多孔集流体2211的一端，也可以是多孔集流体2211的两端均连接有第一极耳2212。第一极耳2212作为电极组件22的负输出极，第一极耳2212用于与负极电极端子相连，以实现电极组件22的电能的输入或输出。
示例性的，在图5中，第一极耳2212连接于多孔集流体2211在第一方向X上的一端，即第一极耳2212连接于多孔集流体2211的延伸段2211a在第一方向X上背离涂覆层2231的一端，当然，在其他实施例中，第一极耳2212也可以连接于多孔集流体2211在垂直于第一方向X和多孔集流体的厚度方向Y上的一端。需要说明的是，第一极耳2212为连接于多孔集流体2211在第一方向X的一端，第一极耳2212可以是连接于多孔集流体2211在第一方向X上的一端，也可以是连接于多孔集流体2211在多孔集流体的厚度方向Y上面向涂覆层2231的一侧，只需第一极耳2212沿第一方向X延伸并凸出多孔集流体2211在第一方向X的一端即可，也就是说，第一极耳2212可以是连接于延伸段2211a在第一方向X上背离涂覆层2231的一端，也可以是连接于延伸段2211a在多孔集流体的厚度方向Y上面向涂覆层2231的一侧，只需第一极耳2212沿第一方向X延伸并凸出延伸段2211a在第一方向X上背离涂覆层2231的一端即可。
需要说明的是，在图3、图4和图5中，电极组件22为卷绕式结构，多孔集流体的厚度方向Y即为电极组件22的径向，第一方向X为负极极片221的宽度方向，也为电极组件22的卷绕中心轴线的延伸方向，当然，第一方向X也可以为电极组件22的卷绕方向，即第一方向X为负极极片221的延伸方向，当第一方向X为负极极片221的延伸方向时，第一方向X与多孔集流体的厚度方向Y相互垂直指第一方向X与多孔集流体的厚度方向Y相交的点在第一方向X上的切线与多孔集流体的厚度方向Y相互垂直。在一些实施例中，若电极组件22为叠片式结构，即负极极片221和正极极片223为沿多孔集流体的厚度方向Y交替层叠的结构，在这种实施例中，第一方向X可以是负极极片221的宽度方向，也可以为负极极片221的长度方向。
沿多孔集流体的厚度方向Y，多孔集流体2211与涂覆层2231面向设置，即负极极片221与正极极片223在多孔集流体的厚度方向Y层叠设置，以使设置于基体2232的一侧的涂覆层2231能够与多孔集流体2211面向设置。
沿第一方向X，多孔集流体2211具有超出涂覆层2231的延伸段2211a，即多孔集流体2211在第一方向X上具有延伸出涂覆层2231的部分，该部分即为延伸段2211a。示例性的，在图5中，沿第一方向X，多孔集流体2211的两端均延伸出涂覆层2231，即多孔集流体2211在第一方向X上的两端均形成有延伸段2211a。
绝缘层224与延伸段2211a对应设置，沿多孔集流体的厚度方向Y，绝缘层224在多孔集流体2211上的投影覆盖延伸段2211a的部分或全部，即在多孔集流体的厚度方向Y上，绝缘层224能够对延伸段2211a的至少部分进行覆盖，也就是说，在多孔集流体的厚度方向Y上，绝缘层224在多孔集流体2211上的投影可以是对部分的延伸段2211a进行了覆盖，也可以是对全部的延伸段2211a进行了覆盖。其中，绝缘层224的装配方式可以是多种，比如，绝缘层224可以是连接于多孔集流体2211的延伸段2211a上，也可以是连接于位于正极极片223和负极极片221之间的隔离膜222上。当绝缘层224连接在延伸段2211a上时，绝缘层224可以是设置于延伸段2211a 面向涂覆层2231的表面上，也可以是设置于延伸段2211a内，即绝缘层224对延伸段2211a进行填充。
电极组件22的负极极片221设置有多孔集流体2211和凸设于多孔集流体2211的至少一端的第一极耳2212，通过将负极极片221的多孔集流体2211在多孔集流体的厚度方向Y上与正极极片223的涂覆层2231面向设置，并将多孔集流体2211在第一方向X上设置为延伸出涂覆层2231，即多孔集流体2211覆盖面向设置的涂覆层2231，从而能够有效缓解电极组件22在使用过程中出现析锂的风险。此外，通过在多孔集流体2211超出涂覆层2231的延伸段2211a上对应设置有绝缘层224，即在多孔集流体2211没有受到正极极片223的涂覆层2231的膨胀力束缚的区域对应设置有绝缘层224，且绝缘层224在多孔集流体的厚度方向Y上的投影覆盖延伸段2211a的部分或全部，从而通过绝缘层224能够对涂覆层2231上析出的锂离子起到一定的阻挡作用，能够有效减少进入多孔集流体2211的延伸段2211a内的锂离子，以缓解因锂金属在多孔集流体2211的延伸段2211a沉积而出现锂金属枝晶生长的情况，且通过绝缘层224能够对延伸段2211a上形成的锂金属枝晶起到一定的阻隔作用，以缓解锂金属枝晶刺破隔离膜222的现象，进而能够有效缓解负极极片221和正极极片223因锂金属枝晶而出现短接的现象，以降低电极组件22在使用过程中的安全隐患。
根据本申请的一些实施例，参见图5和图6所示，沿多孔集流体的厚度方向Y，绝缘层224的投影完全覆盖延伸段2211a。
其中，绝缘层224的投影完全覆盖延伸段2211a，即在多孔集流体的厚度方向Y上，绝缘层224能够对多孔集流体2211的延伸段2211a的整体进行覆盖，也就是说，多孔集流体2211在第一方向X上超出正极极片223的涂覆层2231的区域均被绝缘层224覆盖。
通过将绝缘层224在多孔集流体的厚度方向Y上投影设置为对多孔集流体2211的延伸段2211a的整体进行覆盖，使得多孔集流体2211超出涂覆层2231的延伸段2211a上均对应覆盖有绝缘层224，从而能够有效提升绝缘层224对锂离子的阻挡效果，以进一步减少进入多孔集流体2211的延伸段2211a内的锂离子，从而能够缓解锂离子进入多孔集流体2211的延伸段2211a内进行沉积的现象，且能够提升绝缘层224对延伸段2211a的锂金属枝晶的效阻挡果，以进一步缓解延伸段2211a沉积的锂金属枝晶刺破隔离膜222的现象，进而能够进一步降低正极极片223和负极极片221的短接风险，以提升电极组件22的使用安全性。
在一些实施例中，请继续参见图5和图6所示，沿多孔集流体的厚度方向Y，绝缘层224与涂覆层2231不重叠。
其中，绝缘层224与涂覆层2231不重叠，即绝缘层224未延伸至涂覆层2231和多孔集流体2211在多孔集流体的厚度方向Y之间，也就是说，绝缘层224只对多孔集流体2211在第一方向X上延伸出涂覆层2231的区域进行了覆盖。
通过将绝缘层224设置为与正极极片223的涂覆层2231相互不重叠从而能够缓解因绝缘层224覆盖多孔集流体2211的区域过多而造成电极组件22的容量降低的现象，有利于保证电极组件22的电容量和使用性能。
根据本申请的一些实施例，参照图5和图6，并请进一步参照图8，图8为本申请一些实施例提供的电极组件22的负极极片221的剖视图。沿多孔集流体的厚度方向Y，延伸段2211a面向涂覆层2231的一侧设置有绝缘层224。
其中，延伸段2211a面向涂覆层2231的一侧设置有绝缘层224，即绝缘层224在多孔集流体的厚度方向Y上位于延伸段2211a和隔离膜222之间。在这种实施例中，绝缘层224可以是连接于延伸段2211a上，也可以是连接于隔离膜222上。
通过将绝缘层224设置于延伸段2211a面向涂覆层2231的一侧上，以实现绝缘层224对多孔集流体2211的延伸段2211a进行覆盖，这种结构的电极组件22使得绝缘层224在对涂覆层2231中脱离出来的锂离子起到阻挡作用的同时能够更好地对延伸段2211a沉积的锂金属枝晶起到阻隔效果，以降低隔离膜222被延伸段2211a沉积的锂金属枝晶刺破的风险，从而能够缓解正极极片223和负极极片221之间因锂金属枝晶而造成的短接现象，以提升电极组件22的使用安全性。
在一些实施例中，参见图8所示，绝缘层224连接于延伸段2211a面向涂覆层2231的表面。
其中，绝缘层224连接于延伸段2211a的表面的方式可以是多种，比如，绝缘层224可以通过粘接或吸附等方式连接于延伸段2211a的表面。
通过将绝缘层224连接于多孔集流体2211的延伸段2211a面向涂覆层2231的表面上，这种结构的电极组件22能够保证绝缘层224对多孔集流体2211的延伸段2211a的覆盖效果，以降低绝缘层224与延伸段2211a发生错位而导致覆盖效果不佳的现象，从而能够提升绝缘层224阻挡涂覆层2231脱离出来的锂离子进入多孔集流体2211的延伸段2211a内的效果，以抑制延伸段2211a的锂金属枝晶的生长，且能够对延伸段2211a沉积的锂金属枝晶起到较好的阻隔效果，以降低隔离膜222被锂金属枝晶刺破的风险。
在一些实施例中，参见图5所示，电极组件22还包括隔离膜222。隔离膜222设置于负极极片221与正极极片223之间，以分隔负极极片221与正极极片223。绝缘层224连接于隔离膜222面向延伸段2211a的表面。
其中，绝缘层224连接于隔离膜222面向延伸段2211a的表面上的方式可以是多种，比如，绝缘层224可以通过粘接或吸附等方式连接于隔离膜222面向延伸段2211a的表面上。
示例性的，隔离膜222的材质可以为聚丙烯(polypropylene，PP)或聚乙烯(polyethylene，PE)等。
通过在正极极片223和负极极片221之间设置隔离膜222，并将绝缘层224连接于隔离膜222上，以实现绝缘层224对多孔集流体2211的延伸段2211a进行覆盖，这种结构的电极组件22便于实现，能够有效降低绝缘层224的装配难度，且通过绝缘层224能够进一步提升隔离膜222的强度，以缓解延伸段2211a沉积的锂金属枝晶刺破隔离膜222的现象，从而有利于降低电极组件22的短路风险。
根据本申请的一些实施例，参见图4、图6和图8所示，延伸段2211a在多孔集流体的厚度方向Y上的 两侧均设置有绝缘层224。
其中，在多孔集流体的厚度方向Y上，负极极片221的两侧均设置有正极极片223，对应的，延伸段2211a在多孔集流体的厚度方向Y上的两侧具设置有绝缘层224，也就是说，在多孔集流体的厚度方向Y上，延伸段2211a与相邻的两个隔离膜222之间均设置有绝缘层224。
通过在延伸段2211a沿多孔集流体的厚度方向Y上的两侧均设置绝缘层224，使得绝缘层224能够对延伸段2211a在多孔集流体的厚度方向Y上的两侧进行覆盖，从而一方面能够从延伸段2211a的两侧对锂离子进行阻挡，以减少锂离子进入延伸段2211a进行沉积的现象，另一方面能够从延伸段2211a的两侧为延伸段2211a沉积的锂金属枝晶进行阻隔，以进一步缓解隔离膜222被锂金属枝晶刺破的风险，进而能够进一步提升电极组件22的使用安全性。
根据本申请的一些实施例，参见图6所示，沿多孔集流体的厚度方向Y，绝缘层224的厚度为D 1，满足，1μm≤D 1≤10μm。
示例性的，绝缘层224的厚度D 1可以为1μm、2μm、3μm、5μm、8μm或10μm等。
通过将设置于延伸段2211a在多孔集流体的厚度方向Y上的一侧绝缘层224的厚度设置在1μm到10μm，一方面能够缓解因绝缘层224的厚度过小而造成绝缘层224阻挡锂离子和阻隔锂金属枝晶的效果较差的现象，且能够缓解因绝缘层224的厚度过小而导致制造难度较大的问题，另一方面能够缓解因绝缘层224的厚度过大而导致涂覆层2231与多孔集流体2211之间的间隙过大的现象，从而能够有效缓解电极组件22的内阻过大和析锂的现象。
根据本申请的一些实施例，参照图9和图10，图9为本申请又一些实施例提供的电极组件22的局部剖视图，图10为图9所示的电极组件22的B处的局部放大图。绝缘层224包覆延伸段2211a的至少部分的金属的表面。
其中，绝缘层224包覆延伸段2211a的至少部分的金属的表面，即绝缘层224填充于延伸段2211a内，使得绝缘层224能够对延伸段2211a内的金属进行包覆。
可选地，绝缘层224可以是对延伸段2211a的部分金属进行包覆，也可以是对延伸段2211a的全部金属进行包覆。
通过将绝缘层224设置为包覆于延伸段2211a的至少部分的金属的表面上，也就是说，绝缘层224填充于延伸段2211a，使得绝缘层224能够对延伸段2211a的金属进行包覆，以实现绝缘层224对多孔集流体2211的延伸段2211a进行覆盖，采用这种结构的电极组件22通过绝缘层224能够对锂离子起到较好的阻隔效果，以缓解锂离子接触延伸段2211a的金属后进行沉积的现象，从而能够减少延伸段2211a出现锂金属枝晶生长的现象，以进一步降低正极极片223与负极极片221出现短接的风险。
根据本申请的一些实施例，参照图9和图10，并请进一步参照图11，图11为本申请又一些实施例提供的电极组件22的负极极片221的剖视图。延伸段2211a具有面向涂覆层2231的第一表面2211b，沿多孔集流体的厚度方向Y，绝缘层224从第一表面2211b向延伸段2211a的内部延伸。
其中，绝缘层224从第一表面2211b向延伸段2211a的内部延伸，即绝缘层224优先对延伸段2211a面向涂覆层2231的表面的金属进行包覆，再从延伸段2211a面向涂覆层2231的表面向延伸段2211a的内部进行延伸，以对延伸段2211a的内部的金属进行包覆。
通过将绝缘层224设置为从延伸段2211a的第一表面2211b向延伸段2211a的内部延伸的结构，采用这种结构绝缘层224能够对延伸段2211a的第一表面2211b的金属进行包覆，以抑制延伸段2211a的第一表面2211b接触锂离子后出现锂金属沉积的现象，且能够对延伸段2211a的内部沉积的锂金属枝晶起到一定的阻隔作用，从而能够进一步提升电极组件22的使用安全性。
根据本申请的一些实施例，请参见图10和图11所示，延伸段2211a在多孔集流体的厚度方向Y上的两侧均具有第一表面2211b，且延伸段2211a设置有两个绝缘层224，两个绝缘层224分别从两个第一表面2211b向延伸段2211a的内部延伸。
其中，两个绝缘层224分别从两个第一表面2211b向延伸段2211a的内部延伸，即在多孔集流体的厚度方向Y上，延伸段2211a的两侧的表面均设置有绝缘层224，且两个绝缘层224分别从延伸段2211a的两侧的表面向延伸段2211a的内部延伸。
示例性的，在图11中，延伸段2211a的两个第一表面2211b上设置的绝缘层224均从第一表面2211b向延伸段2211a的内部延伸，且两个绝缘层224在多孔集流体的厚度方向Y上存在间隙，即两个绝缘层224配合对延伸段2211a的部分金属进行包覆。当然，在一些实施例中，参照图12所示，图12为本申请又一些实施例提供的电极组件22的负极极片221在另一些实施例中的剖视图，两个绝缘层224分别从延伸段2211a的两个第一表面2211b向延伸段2211a的内部延伸，且两个绝缘层224相互连接，也就是说，两个绝缘层224配合对延伸段2211a的全部金属进行包覆。
通过在延伸段2211a沿多孔集流体的厚度方向Y上的两个第一表面2211b上均设置绝缘层224，且两个绝缘层224分别从两个第一表面2211b想延伸段2211a的内部延伸，使得绝缘层224能够对延伸段2211a在多孔集流体的厚度方向Y上的两侧进行覆盖，从而一方面能够抑制延伸段2211a的两个第一表面2211b接触锂离子后出现锂金属沉积的现象，以缓解延伸段2211a在多孔集流体的厚度方向Y上的两个第一表面2211b出现锂金属枝晶生长的情况，另一方面能够从延伸段2211a的两侧为延伸段2211a的内部沉积的锂金属枝晶进行阻隔，以进一步缓解隔离膜222被锂金属枝晶刺破的风险，进而能够进一步提升电极组件22的使用安全性。
根据本申请的一些实施例，参见图10和图11所示，沿多孔集流体的厚度方向Y，绝缘层224的延伸深度为D 2，延伸段2211a的厚度为D 3，满足，1μm≤D 2≤D 3/2。
其中，1μm≤D 2≤D 3/2，即在多孔集流体的厚度方向Y上，绝缘层224填充于延伸段2211a内的深度为1μm到填充延伸段2211a的一半。当设置于延伸段2211a的两个第一表面2211b上的两个绝缘层224在多孔集流体的厚度方向Y上的延伸深度D 2均为D 3/2时，则两个绝缘层224配合对延伸段2211a的全部金属进行包覆。
通过将绝缘层224在延伸段2211a内的延伸深度设置在1μm到延伸段2211a的厚度的一半，从而一方面能够缓解因绝缘层224的延伸深度过小而造成延伸段2211a沉积的锂金属枝晶极容易生长并超出第一表面2211b的现象，且能够缓解因绝缘层224的延伸深度过小而导致制造难度较大的问题，另一方面能够缓解因绝缘层224的延伸深度过大而导致延伸段2211a的两侧设置的绝缘层224出现相互干涉的现象，且能够减少绝缘层224的浪费。
根据本申请的一些实施例，参见图5和图8所示，沿第一方向X，多孔集流体2211的两端均具有延伸段2211a，每个延伸段2211a均对应设置有绝缘层224。
其中，多孔集流体2211的两端均具有延伸段2211a，即在第一方向X上，多孔集流体2211的两端均超出正极极片223的涂覆层2231。
多孔集流体2211在第一方向X上的两端均形成有延伸段2211a，即多孔集流体2211在第一方向X上的两端均超出涂覆层2231，从而一方面能够保证多孔集流体2211在多孔集流体的厚度方向Y上对涂覆层2231的覆盖效果，以进一步缓解电极组件22的析锂现象，另一方面通过在多孔集流体2211的两端超出涂覆层2231的延伸段2211a上均设置有绝缘层224，以对多孔集流体2211的两端均能够起到一定的覆盖作用，以缓解锂金属枝晶在多孔集流体2211的两端进行沉积的现象。
根据本申请的一些实施例，绝缘层224的弹性模量为E，满足，E≥1Gpa。绝缘层224的弹性模量的值可以参见国家标准，在此不再赘述。
采用弹性模量大于或等于1GPa的绝缘层224，使得这种绝缘层224具有较好的强度和韧性，一方面能够有效降低绝缘层224在使用过程中出现损坏的现象，以提升电极组件22的使用寿命，另一方面能够对锂金属枝晶起到较好的阻挡作用，有利于减少绝缘层224被锂金属枝晶刺破的现象，从而能够有效降低电池单体20的使用风险。
在一些实施例中，绝缘层224为绝缘胶带或绝缘涂层。
其中，若绝缘层224为绝缘胶带，绝缘层224可以为蓝胶胶带或绿胶胶带等，绝缘层224通过粘接方式连接于多孔集流体2211的延伸段2211a或隔离膜222上；若绝缘层224为绝缘涂层，绝缘层224可以为环氧树脂类绝缘漆或氧化铝陶瓷涂层等，绝缘层224通过涂覆方式连接于多孔集流体2211的延伸段2211a或隔离膜222上，其弹性模量可参见下表所示。
材质 蓝胶 绿胶 环氧树脂类绝缘漆 氧化铝陶瓷涂层
弹性模量/GPa ≥1 ≥1 ≥2 ≥1
需要说明的是，在绝缘层224为设置于多孔集流体2211的延伸段2211a在多孔集流体的厚度方向Y上面向涂覆层2231的一侧的实施例中，绝缘层224可以是绝缘胶带或绝缘涂层，使得绝缘层224能够通过粘接或涂覆等方式连接于延伸段2211a面向涂覆层2231的表面上或隔离膜222面向延伸段2211a的表面上；在绝缘层224为包覆延伸段2211a的至少部分的金属表面的实施例中，绝缘层224可以采用绝缘涂层，以便于绝缘层224能够填充于延伸段2211a内，从而实现对延伸段2211a的至少部分的金属进行包覆。
采用绝缘胶带或绝缘涂层作为绝缘层224对多孔集流体2211的延伸段2211a进行覆盖，这种结构的绝缘层224只需将绝缘层224粘接或涂覆于多孔集流体2211的延伸段2211a即可，便于对电极组件22进行装配，有利于提升电极组件22的生产效率。
根据本申请的一些实施例，参见图5和图8所示，沿多孔集流体的厚度方向Y，第一极耳2212的最大厚度小于多孔集流体2211的厚度。
其中，第一极耳2212的最大厚度小于多孔集流体2211的厚度，即第一极耳2212在多孔集流体的厚度方向Y上的任意一个位置的厚度均小于多孔集流体2211的厚度。
通过将第一极耳2212在多孔集流体的厚度方向Y上的最大厚度设置为小于多孔集流体2211的厚度，一方面便于后续将第一极耳2212与其他部件进行装配连接，另一方面在电极组件22的生产过程中，在将负极极片221的多孔集流体2211设置为在第一方向X上具有超出涂覆层2231的延伸段2211a时便于对多孔集流体2211和第一极耳2212进行有效区分，以提高电极组件22的制造精度。
根据本申请的一些实施例，请继续参见图5和图8所示，多孔集流体2211与第一极耳2212为一体式结构，第一极耳2212连接于延伸段2211a在第一方向X上远离涂覆层2231的一端。其中，第一极耳2212包括主体段2212a和过渡段2212b，沿第一方向X，过渡段2212b连接于主体段2212a和延伸段2211a之间，且过渡段2212b在多孔集流体的厚度方向Y上的厚度从靠近主体段2212a的一端向靠近延伸段2211a的一端逐渐增大。
其中，第一极耳2212为负极极片221在第一方向X上的一端通过辊压等工艺形成的结构，从而使得负极极片221形成有多孔集流体2211和凸出于多孔集流体2211在第一方向X上的一端且厚度较小的第一极耳2212，即使得第一极耳2212形成有主体段2212a和连接于主体段2212a和多孔集流体2211的延伸段2211a之间的过渡段2212b，主体段2212a用于与负极电极端子相连。在这种实施例中，只需将绝缘层224设置为覆盖负极极片221未被辊压压缩的部分(即多孔集流体2211)即可。
需要说明的是，在多孔集流体2211与第一极耳2212为一体式结构的实施例中，参见图5和图8所示，若将绝缘层224设置于延伸段2211a面向涂覆层2231的一侧，则只需将绝缘层224设置为覆盖多孔集流体2211的厚度未减小且在第一方向X上超出涂覆层2231的区域即可；参见图9和图11所示，若将绝缘层224设置为包覆延伸段2211a的至少部分金属的表面，则只需将绝缘层224填充于多孔集流体2211的厚度未减小且在第一方向X上 超出涂覆层2231的区域即可。
通过将多孔集流体2211和第一极耳2212设置为一体成型的结构，使得第一极耳2212形成有主体段2212a和连接于主体段2212a和多孔集流体2211的延伸段2211a之间的过渡段2212b，且过渡段2212b在多孔集流体的厚度方向Y上的厚度从靠近主体段2212a的一端向靠近多孔集流体2211的延伸段2211a的一端逐渐增大，从而实现第一极耳2212凸出于多孔集流体2211的一端，采用这种结构的负极极片221能够有效提高第一极耳2212的结构强度，且能够有效提升第一极耳2212与多孔集流体2211之间的连接强度。
根据本申请的一些实施例，参照图13-图16，图13为本申请再一些实施例提供的电极组件22的局部剖视图，图14为图13所示的电极组件22的C处的局部放大图，图15为本申请另一些实施例提供的电极组件22的局部剖视图，图16为图15所示的电极组件22的D处的局部放大图。多孔集流体2211与第一极耳2212为分体式结构，第一极耳2212连接于延伸段2211a在多孔集流体的厚度方向Y上的一侧，且沿第一方向X，第一极耳2212凸出于延伸段2211a远离涂覆层2231的一端。
其中，第一极耳2212与多孔集流体2211为分体式结构，即第一极耳2212与多孔集流体2211为相互独立的部件，第一极耳2212连接于多孔集流体2211的延伸段2211a在多孔集流体的厚度方向Y上的一侧并沿第一方向X延伸出多孔集流体2211的一端。在这种实施例中，第一极耳2212与多孔集流体2211在多孔集流体的厚度方向Y具有相互重叠的区域，第一极耳2212的部分与多孔集流体2211相互连接后沿第一方向X延伸出多孔集流体2211的一端。
示例性的，第一极耳2212焊接于多孔集流体2211的延伸段2211a并形成焊印2213。
需要说明的是，在多孔集流体2211与第一极耳2212为分体式结构的实施例中，参见图13和图14所示，若将绝缘层224设置于延伸段2211a面向涂覆层2231的一侧，则需要将绝缘层224设置为覆盖多孔集流体2211在第一方向X上超出涂覆层2231的部分，且使得绝缘层224能够对第一极耳2212和多孔集流体2211相互层叠并相连形成焊印2213的区域进行覆盖；参见图15和图16所示，若将绝缘层224设置为包覆延伸段2211a的至少部分金属的表面，则只需将绝缘层224设置为包覆多孔集流体2211在第一方向X上超出涂覆层2231的部分的金属即可，无需对第一极耳2212与多孔集流体2211的延伸段2211a相互焊接形成的焊印2213进行包覆。当然，在一些实施例中，参照图17和图18，图17为本申请再又一些实施例提供的电极组件22的局部剖视图，图18为图17所示的电极组件22的E处的局部放大图，还可以在第一极耳2212与多孔集流体2211的延伸段2211a相互焊接形成的焊印2213的表面设置绝缘层224，使得绝缘层224还能够对第一极耳2212与多孔集流体2211的延伸段2211a相互焊接形成的焊印2213进行覆盖。
通过将多孔集流体2211和第一极耳2212设置为分体式结构，并将第一极耳2212连接于多孔集流体2211的延伸段2211a在多孔集流体的厚度方向Y上的一侧后沿第一方向X凸出于延伸段2211a远离涂覆层2231的一端，以实现第一极耳2212凸出于多孔集流体2211的一端，这种结构的负极极片221的制造难度较低，有利于提升电极组件22的生产效率。
根据本申请的一些实施例，参见图4和图5所示，电极组件22为卷绕式电极组件22，第一方向X与电极组件22的卷绕轴线方向一致。
其中，电极组件22为卷绕式结构，使得第一方向X为电极组件22的卷绕轴线的延伸方向，即电极组件22的卷绕方向所在的平面与第一方向X相互垂直，且使得多孔集流体的厚度方向Y为电极组件22的径向。
通过将电极组件22设置为卷绕式的结构，且第一方向X与电极组件22的卷绕轴线方向一致，采用这种结构的电极组件22便于制造和生产，有利于降低正极极片223和负极极片221出现错位的现象。
根据本申请的一些实施例，多孔集流体2211的材质为泡沫金属。
示例性的，多孔集流体2211的材质为泡沫铜。当然，在其他实施例中，多孔集流体2211的材质也可以为泡沫镍等。采用泡沫铜作为多孔集流体2211的材质能够使得多孔集流体2211具有较好的导电性能，从而有利于减少具有这种负极极片221的电极组件22的内阻，以提升电池单体20的使用性能。
采用泡沫金属的多孔集流体2211使得多孔集流体2211具有与锂离子直接进行反应的功能，以实现负极极片221的电能输入或输出，且这种结构的多孔集流体2211能够实现锂离子在多孔集流体2211的内部进行沉积，有利于降低多孔集流体2211的表面出现锂金属沉积的风险。
根据本申请的一些实施例，本申请实施例还提供了一种电池单体20，电池单体20包括外壳21和以上任一方案的电极组件22，电极组件22容纳于外壳21内。
根据本申请的一些实施例，本申请实施例还提供了一种电池100，电池100包括以上任一方案的电池单体20。
根据本申请的一些实施例，本申请实施例还提供了一种用电装置，用电装置包括以上任一方案的电池单体20，并且电池单体20用于为用电装置提供电能。
用电装置可以是前述任一应用电池单体20的设备或***。
根据本申请的一些实施例，参见图3至图8所示，本申请提供了一种电极组件22，电极组件22包括负极极片221、隔离膜222、正极极片223和绝缘层224。隔离膜222设置于负极极片221和正极极片223之间，以分隔负极极片221和正极极片223。正极极片223包括基体2232和涂覆于基体2232的两侧的涂覆层2231，沿第一方向X，基体2232的一端延伸出涂覆层2231形成第二极耳2232a。负极极片221包括多孔集流体2211和在第一方向X上连接于多孔集流体2211的一端的第一极耳2212，沿多孔集流体的厚度方向Y，多孔集流体2211与涂覆层2231面向设置，沿第一方向X，多孔集流体2211的两端均超出涂覆层2231并形成延伸段2211a，第一方向X垂直于多孔集流体的厚度方向Y。多孔集流体2211与第一极耳2212为一体式结构，第一极耳2212包括主体段2212a和过渡段2212b，沿第一方向X，过渡段2212b连接于主体段2212a和延伸段2211a之间，且过渡段2212b在多孔集流体 的厚度方向Y上的厚度从靠近主体段2212a的一端向靠近延伸段2211a的一端逐渐增大。延伸段2211a面向涂覆层2231的一侧设置有绝缘层224，且绝缘层224连接于延伸段2211a的表面上。沿多孔集流体的厚度方向Y，绝缘层224在多孔集流体2211上的投影完全覆盖延伸段2211a，且绝缘层224与涂覆层2231不重叠。其中，沿多孔集流体的厚度方向Y，绝缘层224的厚度为D 1，满足，1μm≤D 1≤10μm。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互结合。
以上仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (23)

  1. 一种电极组件，包括：
    正极极片，包括涂覆层；
    负极极片，包括多孔集流体和连接于所述多孔集流体的至少一端的第一极耳，沿所述多孔集流体的厚度方向，所述多孔集流体与所述涂覆层面向设置，沿第一方向，所述多孔集流体具有超出所述涂覆层的延伸段，所述第一方向垂直于所述多孔集流体的厚度方向；以及
    绝缘层，与所述延伸段对应设置，沿所述多孔集流体的厚度方向，所述绝缘层在所述多孔集流体上的投影覆盖所述延伸段的部分或全部。
  2. 根据权利要求1所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述绝缘层的投影完全覆盖所述延伸段。
  3. 根据权利要求2所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述绝缘层与所述涂覆层不重叠。
  4. 根据权利要求1-3任一项所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述延伸段面向所述涂覆层的一侧设置有所述绝缘层。
  5. 根据权利要求4所述的电极组件，其中，所述绝缘层连接于所述延伸段面向所述涂覆层的表面。
  6. 根据权利要求4所述的电极组件，其中，所述电极组件还包括：
    隔离膜，设置于所述负极极片与所述正极极片之间，以分隔负极极片与所述正极极片；
    其中，所述绝缘层连接于所述隔离膜面向所述延伸段的表面。
  7. 根据权利要求4-6任一项所述的电极组件，其中，所述延伸段在所述多孔集流体的厚度方向上的两侧均设置有所述绝缘层。
  8. 根据权利要求4-7任一项所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述绝缘层的厚度为D 1，满足，1μm≤D 1≤10μm。
  9. 根据权利要求1-3任一项所述的电极组件，其中，所述绝缘层包覆所述延伸段的至少部分的金属的表面。
  10. 根据权利要求9所述的电极组件，其中，所述延伸段具有面向所述涂覆层的第一表面，沿所述多孔集流体的厚度方向，所述绝缘层从所述第一表面向所述延伸段的内部延伸。
  11. 根据权利要求10所述的电极组件，其中，所述延伸段在所述多孔集流体的厚度方向上的两侧均具有所述第一表面，且所述延伸段设置有两个所述绝缘层，两个所述绝缘层分别从两个所述第一表面向所述延伸段的内部延伸。
  12. 根据权利要求11所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述绝缘层的延伸深度为D 2，所述延伸段的厚度为D 3，满足，1μm≤D 2≤D 3/2。
  13. 根据权利要求1-12任一项所述的电极组件，其中，沿所述第一方向，所述多孔集流体的两端均具有所述延伸段，每个所述延伸段均对应设置有所述绝缘层。
  14. 根据权利要求1-13任一项所述的电极组件，其中，所述绝缘层的弹性模量为E，满足，E≥1Gpa。
  15. 根据权利要求1-14任一项所述的电极组件，其中，所述绝缘层为绝缘胶带或绝缘涂层。
  16. 根据权利要求1-15任一项所述的电极组件，其中，沿所述多孔集流体的厚度方向，所述第一极耳的最大厚度小于所述多孔集流体的厚度。
  17. 根据权利要求16所述的电极组件，其中，所述多孔集流体与所述第一极耳为一体式结构，所述第一极耳连接于所述延伸段在所述第一方向上远离所述涂覆层的一端；
    其中，所述第一极耳包括主体段和过渡段，沿所述第一方向，所述过渡段连接于所述主体段和所述延伸段之间，且所述过渡段在所述多孔集流体的厚度方向上的厚度从靠近所述主体段的一端向靠近所述延伸段的一端逐渐增大。
  18. 根据权利要求16所述的电极组件，其中，所述多孔集流体与所述第一极耳为分体式结构，所述第一极耳连接于所述延伸段在所述多孔集流体的厚度方向上的一侧，且沿所述第一方向，所述第一极耳凸出于所述延伸段远离所述涂覆层的一端。
  19. 根据权利要求1-18任一项所述的电极组件，其中，所述电极组件为卷绕式电极组件，所述第一方向与所述电极组件的卷绕轴线方向一致。
  20. 根据权利要求1-19任一项所述的电极组件，其中，所述多孔集流体的材质为泡沫金属。
  21. 一种电池单体，包括：
    外壳；以及
    如权利要求1-20任一项所述的电极组件，所述电极组件容纳于所述外壳内。
  22. 一种电池，包括如权利要求21所述的电池单体。
  23. 一种用电装置，包括如权利要求21所述的电池单体。
PCT/CN2022/143534 2022-10-21 2022-12-29 电极组件、电池单体、电池及用电装置 WO2024082448A1 (zh)

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CN109935783A (zh) * 2019-02-21 2019-06-25 宁德新能源科技有限公司 电化学装置和电子装置
CN111416103A (zh) * 2019-01-08 2020-07-14 宁德新能源科技有限公司 用于提高电池性能的具有支架结构的复合层和保护层的电极
JP2021039876A (ja) * 2019-09-02 2021-03-11 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． 全固体電池

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CN104466097A (zh) * 2014-12-16 2015-03-25 东莞新能源科技有限公司 一种电极片及含有该电极片的锂离子电池
CN111416103A (zh) * 2019-01-08 2020-07-14 宁德新能源科技有限公司 用于提高电池性能的具有支架结构的复合层和保护层的电极
CN109935783A (zh) * 2019-02-21 2019-06-25 宁德新能源科技有限公司 电化学装置和电子装置
JP2021039876A (ja) * 2019-09-02 2021-03-11 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． 全固体電池

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