WO2025167263A1 - 负极集流体及其制备方法、钠二次电池、用电设备 - Google Patents

负极集流体及其制备方法、钠二次电池、用电设备

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Publication number
WO2025167263A1
WO2025167263A1 PCT/CN2024/133177 CN2024133177W WO2025167263A1 WO 2025167263 A1 WO2025167263 A1 WO 2025167263A1 CN 2024133177 W CN2024133177 W CN 2024133177W WO 2025167263 A1 WO2025167263 A1 WO 2025167263A1
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WIPO (PCT)
Prior art keywords
sodium
functional layer
current collector
negative electrode
electrode current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/133177
Other languages
English (en)
French (fr)
Inventor
陈孔耀
王铈汶
屈仁杰
黄耿鸿
张星
张�杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xiamen Hithium Energy Storage Technology Co Ltd
Shenzhen Hithium Energy Storage Technology Co Ltd
Original Assignee
Xiamen Hithium Energy Storage Technology Co Ltd
Shenzhen Hithium Energy Storage Technology Co Ltd
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Application filed by Xiamen Hithium Energy Storage Technology Co Ltd, Shenzhen Hithium Energy Storage Technology Co Ltd filed Critical Xiamen Hithium Energy Storage Technology Co Ltd
Publication of WO2025167263A1 publication Critical patent/WO2025167263A1/zh
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/054—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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H01M10/446—Initial charging measures
    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/134—Electrodes based on metals, Si or alloys
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • 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
    • H01M4/66—Selection of materials
    • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
    • 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
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • 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 disclosure relates to the field of battery technology, and in particular to a negative electrode current collector and a preparation method thereof, a sodium secondary battery, and an electrical device.
  • a negative electrode current collector comprising a substrate; a functional layer disposed on at least one side of the substrate, the functional layer including a multifunctional additive comprising Na x MN y *zH 2 O, wherein M comprises atoms capable of forming an alloy with Na, N comprises at least one of an O atom, a S atom, and a Se atom, and 0 ⁇ x ⁇ 5, 0 ⁇ y ⁇ 5, and 0 ⁇ z ⁇ 5.
  • the multifunctional additive simultaneously exhibits sodium affinity, sodium replenishment, and sodium storage capabilities, thereby reducing the nucleation overpotential of sodium deposition and improving the uniformity of sodium deposition.
  • the multifunctional additive can exert a sodium replenishment effect, thereby improving the coulombic efficiency and cycle life of the battery.
  • the multifunctional additive can also store sodium ions, exerting a sodium storage function and increasing the specific capacity of the battery.
  • a second aspect of the present disclosure provides a method for preparing the negative electrode current collector of the first aspect of the present disclosure, comprising forming a functional layer on at least one side of the substrate, the functional layer comprising a multifunctional additive, the multifunctional additive comprising Na x MN y *zH 2 O, wherein M comprises atoms capable of forming an alloy with Na, N comprises at least one of an O atom, an S atom, and a Se atom, and 0 ⁇ x ⁇ 5, 0 ⁇ y ⁇ 5, and 0 ⁇ z ⁇ 5.
  • the negative electrode current collector prepared by this method comprises the multifunctional additive, which has the ability to simultaneously favor sodium, replenish sodium, and store sodium. This can reduce the nucleation overpotential of sodium deposition and improve the uniformity of sodium deposition.
  • the multifunctional additive can exert a sodium replenishing effect, thereby improving the coulombic efficiency and cycle life of the battery.
  • the multifunctional additive can also store sodium ions, exerting a sodium storage function, thereby improving the specific capacity of the battery.
  • a third aspect of the present disclosure provides a sodium secondary battery, comprising the negative electrode current collector provided by the first aspect of the present disclosure or the negative electrode current collector prepared by the method provided by the second aspect of the present disclosure.
  • metallic sodium is deposited on the side of the functional layer away from the substrate. This improves the coulombic efficiency, cycle life, and specific capacity of the sodium secondary battery.
  • FIG1 shows a schematic structural diagram of a negative electrode current collector according to an embodiment of the present disclosure.
  • a negative electrode current collector is provided.
  • the negative electrode current collector 10 includes a substrate 11 and a functional layer 12 disposed on at least one side of the substrate 11.
  • the functional layer 12 includes a multifunctional additive comprising Na x MN y *zH 2 O, wherein M includes atoms capable of forming an alloy with Na, N includes at least one of O, S, and Se atoms, and 0 ⁇ x ⁇ 5, 0 ⁇ y ⁇ 5, and 0 ⁇ z ⁇ 5.
  • the multifunctional additive has sodium affinity, sodium replenishment, and sodium storage capabilities, which can reduce the nucleation overpotential of sodium deposition and improve the uniformity of sodium deposition.
  • the multifunctional additive can exert a sodium replenishment effect, thereby improving the coulombic efficiency and cycle life of the battery.
  • the multifunctional additive can also store sodium ions, exerting a sodium storage function and increasing the specific capacity of the battery.
  • the negative electrode current collector 10 disclosed herein includes a functional layer 12 comprising a multifunctional additive, NaxMNy * zH2O .
  • the Na component acts as a "sodium reservoir” during battery charge and discharge, releasing sodium ions when the battery's overall sodium content decreases, replenishing sodium and improving the battery's coulombic efficiency.
  • the M component is intrinsically sodium -philic and readily reacts with sodium ions to form sodium-philic alloys (e.g., Na-Sn alloys and Na-Zn alloys).
  • the functional layer 12 is disposed on at least one surface of the substrate 11 .
  • M includes at least one of Sn, Sb, Bi, and Zn atoms
  • N includes at least one of O, S, and Se atoms.
  • Sn, Sb, Bi, and Zn atoms are intrinsically sodium-philic, which can reduce the nucleation overpotential and sodium deposition/stripping polarization potential of sodium deposition on the negative electrode current collector, improve the uniformity and density of sodium deposition, reduce the probability of sodium dendrite formation, reduce the risk of the separator being pierced by sodium dendrites, and cause a battery short circuit, and improve the battery's cycle life.
  • M comprises Sn atoms
  • N comprises at least one of O and S atoms.
  • M comprises Sn atoms
  • one Sn ion can bind to 3-4 Na + atoms, further enhancing sodium affinity and sodium storage capacity, improving the uniformity and density of sodium deposition, increasing the battery's Coulombic efficiency and cycle life, and improving the battery's specific capacity.
  • N comprises at least one of O and S atoms
  • the stability of the multifunctional additive can be further improved, reducing the risk of oxidative decomposition of the multifunctional additive.
  • Sn, Zn, Sb, and Bi ions are intrinsically sodium-philic and readily react with sodium ions to form sodium-philic alloys (e.g., Na-Sn, Na-Zn, Na-Sb, and Na-Bi alloys).
  • sodium-philic alloys e.g., Na-Sn, Na-Zn, Na-Sb, and Na-Bi alloys.
  • Sn, Zn, Sb, and Bi ions can store large amounts of sodium ions through alloying reactions (e.g., forming Na 15 Sn 4 and Na 3 Bi), acting as a sodium storage mechanism and improving the battery's specific capacity.
  • alloying reactions e.g., forming Na 15 Sn 4 and Na 3 Bi
  • O and S atoms further enhance the structural stability of the multifunctional additive, reducing the risk of oxidative decomposition.
  • the mass proportion of the multifunctional additive in the functional layer 12 is increased, and more and more evenly distributed sodium-affinity, sodium-replenishing and sodium-storage sites are formed on the functional layer 12, further improving the uniformity of the sodium-affinity, sodium-replenishing and sodium-storage capabilities of each region of the functional layer 12, thereby improving the sodium-affinity, sodium-replenishing and sodium-storage capabilities of each region of the functional layer 12.
  • the uniformity of the sodium metal layer formed by high deposition reduces the probability of localized sodium dendrite formation, thereby improving the battery's coulombic efficiency, cycle life, and specific capacity.
  • the content of the multifunctional additive is too low, the number of sodium-loving, sodium-supplementing, and sodium-storage sites formed on the functional layer 12 will be small, which will to some extent affect the multifunctional additive's improvement effect on the sodium deposition/stripping process. If the content of the non-conductive bifunctional additive is too high, it will to some extent affect the transmission of electrons and ions on the negative electrode current collector 10, reducing the reversibility of the sodium deposition/stripping process.
  • the thickness of the functional layer 12 By making the thickness of the functional layer 12 within the above range, the risk of the functional layer 12 falling off due to the functional layer 12 being too thick can also be reduced. If the thickness of the functional layer 12 is too low, the number of sodium-philic, sodium-supplementing, and sodium-storage sites on the surface of the substrate is small, which affects the uniformity of sodium deposition and thus affects its electrochemical performance; if the thickness of the functional layer 12 is too high, that is, the distance from the surface of the functional layer 12 to the surface of the substrate 11 is large, the electron/ion transmission distance will be increased, affecting the rapid sodium deposition/stripping of the battery; moreover, if the thickness of the functional layer 12 is too large, the bonding force between the functional layer 12 and the substrate 11 will be reduced to a certain extent, increasing the risk of the functional layer 12 falling off and poor electrolyte wettability.
  • the functional layer 12 may further include a carbon main material.
  • the carbon main material can provide uniform and stable loading sites for the multifunctional additive, thereby improving the uniformity of the multifunctional additive's distribution in the functional layer 12, improving the uniformity of the sodium affinity, sodium replenishment, and sodium storage capabilities of each region of the functional layer 12, thereby improving the uniformity of sodium deposition, reducing the probability of localized sodium dendrite formation, and thereby improving the coulombic efficiency, cycle life, and specific capacity of the battery.
  • the mass proportion of the carbon main material is 60%-90%, for example, it can be 60%, 65%, 70%, 75%, 80%, 85% or 90%, or it can be a range composed of any of the above values.
  • the mass proportion of the carbon main material is 60%-90%, for example, it can be 60%, 65%, 70%, 75%, 80%, 85% or 90%, or it can be a range composed of any of the above values.
  • the main carbon material includes at least one of carbon black, carbon fiber, carbon nanotube, and graphene.
  • the functional layer 12 may further include an adhesive, thereby improving the bonding force between the functional layer 12 and the substrate 11 and preventing the functional layer 12 from falling off.
  • the mass proportion of the binder is 5%-30%.
  • it can be 5%, 10%, 15%, 20%, 25% or 30%, etc., or it can be a range composed of any of the above numerical values.
  • the mass proportion of the binder can be 10%-20%.
  • the functional layer 12 includes a multifunctional additive, a carbon material, and a binder.
  • the method for preparing the negative electrode current collector 10 may include: mixing the multifunctional additive, the carbon material, and the binder with a solvent to form a slurry, forming the slurry on at least one surface of the substrate 11, and drying to form the functional layer 12.
  • mechanical stirring or ball milling stirring may be performed during the process of forming the slurry to improve the uniformity of the slurry.
  • the base material 11 of the negative electrode current collector 10 may be sodium metal.
  • the substrate 11 of the negative electrode current collector 10 can be a metal foil, a porous metal plate, or a composite current collector.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate 11.
  • the composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate 11 (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE)) or the like.
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the substrate 11 of the negative electrode current collector 10 may be aluminum.
  • a second aspect of the present disclosure provides a method for preparing the negative electrode current collector 10 of the first aspect of the present disclosure, comprising: forming a functional layer 12 on at least one side of the substrate 11, the functional layer 12 comprising a multifunctional additive, the multifunctional additive comprising NaxMNy * zH2O , wherein M comprises atoms that can form an alloy with Na, N comprises at least one of an O atom, an S atom, and a Se atom, and 0 ⁇ x ⁇ 5, 0 ⁇ y ⁇ 5, and 0 ⁇ z ⁇ 5.
  • the method may further include: mixing a carbon main material, a multifunctional additive, and a first solvent, drying, and then heat-treating to obtain a mixture; mixing the mixture, a binder, and a second solvent to form a slurry, forming the slurry on at least one side of the substrate 11, and drying to form the functional layer 12.
  • the adhesion of the multifunctional additive to the carbon main material is improved, the uniformity of the mixing of the multifunctional additive and the carbon main material is improved, and the uniformity of sodium deposition in various regions of the functional layer 12 is improved.
  • the carbon main material, the multifunctional additive, and water can be mixed so that the carbon main material and the multifunctional additive are evenly mixed in the water.
  • a high-temperature heat treatment is performed to improve the adhesion between the multifunctional additive and the carbon main material.
  • the mixture is then mixed with a binder and a second solvent to form a slurry, which is formed on at least one side of the substrate 11.
  • a functional layer 12 in which the multifunctional additive is evenly distributed and not easy to fall off is formed.
  • the slurry may be applied to at least one surface of the substrate 11 by rolling, brushing, spraying, or the like.
  • the temperature of the heat treatment may be 100°C-800°C.
  • it may be 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C or 800°C, or it may be a range composed of any of the above values.
  • the adhesion between the carbon main material and the multifunctional additive can be improved, the uniformity of the distribution of the multifunctional additive in the carbon main material can be improved, and the uniformity of the distribution of the multifunctional additive in each area of the functional layer can be improved, so that each area of the functional layer has a uniform sodium affinity, sodium supplementation and sodium storage capacity, and the uniformity of sodium deposition is improved.
  • the temperature of the heat treatment may be 400°C-600°C.
  • a third aspect of the present disclosure provides a sodium secondary battery, comprising the negative electrode current collector 10 provided in the first aspect of the present disclosure, or the negative electrode current collector 10 prepared by the method provided in the second aspect of the present disclosure.
  • metallic sodium is deposited on the side of the functional layer 12 away from the substrate 11. This improves the coulombic efficiency, cycle life, and specific capacity of the sodium secondary battery.
  • the sodium secondary battery may be a sodium metal battery or a negative electrode-less sodium battery.
  • the sodium secondary battery further includes a positive electrode sheet and a separator, wherein the separator is disposed between the positive electrode sheet and the negative electrode current collector.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector.
  • the positive electrode active material layer includes a positive electrode active material, a positive electrode binder, and a positive electrode conductive agent.
  • the positive electrode current collector can be made of a material with good conductivity and mechanical strength, preferably aluminum foil.
  • the specific types of positive electrode active materials are not particularly limited, and those skilled in the art can select them according to actual needs.
  • the positive electrode active materials include at least one of sodium vanadium phosphate, sodium vanadium fluorophosphate, sodium iron phosphate, sodium iron pyrophosphate and composite sodium iron phosphate.
  • the specific type of the positive electrode conductive agent is not particularly limited, and those skilled in the art can select it according to actual needs.
  • the positive electrode conductive agent includes at least one of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the specific type of the positive electrode binder is not particularly limited, and those skilled in the art may select it according to actual needs.
  • the positive electrode binder includes at least one of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE).
  • the preparation method of the positive electrode plate includes: mixing the positive electrode active material, positive electrode binder and positive electrode conductive agent in a preset proportion, adding a solvent and stirring evenly to form a positive electrode slurry, then coating it on the current collector, drying it, and finally cutting it into a specific shape of positive electrode plates according to the different battery shells for use.
  • the carbon main material, multifunctional additive and water are mixed in a mass ratio of 67:8:100, mechanically stirred for 2 hours to make them mixed evenly, and then the water is dried after mixing evenly. Then the mixture is transferred to a nitrogen-protected tubular furnace, heated to 500°C and heat treated for 3 hours.
  • the heat-treated product is mixed with the binder in a mass ratio of 75:25, and then a certain amount of solvent (nitromethylpyrrolidone) is added and stirred into a uniform slurry with a solid content of 10%.
  • the slurry is coated on aluminum foil using a coater and dried in an oven.
  • the current collector is cold pressed by a roller press to obtain a functional layer with a thickness of 8 ⁇ m.
  • the active material sodium vanadium phosphate
  • conductive agent Ketjen black
  • binder PVDF
  • solvent nitromethyl pyrrolidone
  • a 16 ⁇ m polyethylene film was used as the separator.
  • the positive electrode sheet, separator, and negative electrode current collector are stacked in order, with the separator placed between the positive electrode sheet and the negative electrode current collector, and the above-mentioned electrolyte is added to assemble a full battery.
  • a constant current charge and discharge test was performed on the half-cell on a battery charge and discharge tester; the charge and discharge currents were both set to 2 mA/cm 2 , the discharge cut-off capacity was set to 2 mAh/cm 2 , and the charge cut-off voltage was set to 1.5 V; the 10th cycle charge and discharge curve of the battery was plotted, and its sodium nucleation overpotential was read, which was the sodium deposition nucleation overpotential of the negative electrode current collector; the 10th cycle charge and discharge curve of the battery was plotted, and its charge and discharge polarization potential was calculated, which was the polarization potential of the negative electrode current collector.
  • the charge and discharge current density is set to 100mA/g, and the charge and discharge voltage range is set to 2.5V-3.8V.
  • the discharge capacity of the first cycle is the battery's initial discharge capacity.
  • Full batteries were tested at constant current on a battery charge and discharge tester. Based on the mass of the positive electrode active material, the charge and discharge current density was set to 100 mA/g, and the charge and discharge voltage range was set to 2.5 V to 3.8 V. The ratio of the discharge capacity at the 100th cycle to the discharge capacity at the 1st cycle is the 100-cycle capacity retention rate.
  • Full batteries were tested using a battery charge and discharge tester at a constant current. Based on the mass of the positive electrode active material, the charge and discharge current density was set to 100 mA/g, and the charge and discharge voltage range was set to 2.5 V to 3.8 V. The average coulombic efficiency from the first to the 100th cycle was the 100-cycle average coulombic efficiency.
  • the thickness (T 0 ) of the plain foil used in the above embodiment is measured using a thickness gauge.
  • the thickness (T 1 ) of the negative electrode current collector coated on both sides with a functional coating prepared in the above embodiment is measured using a thickness gauge.
  • the negative electrode current collector in Comparative Example 1 does not include a functional layer
  • the negative electrode current collector in Comparative Example 2 is provided with a functional layer, but the functional layer is not provided with a multifunctional additive
  • the negative electrode current collector in Comparative Example 3 is provided with a functional layer and an additive is provided on the functional layer, but the additive is of a different type from the multifunctional additive disclosed herein
  • the negative electrode current collectors of Examples 1 to 19 are all provided with a functional layer
  • the functional layer includes a multifunctional additive having sodium affinity, sodium replenishment and sodium storage functions.
  • the sodium deposition potential and polarization potential in Examples 1 to 19 are lower than those in Comparative Examples 1-3, and the first discharge specific capacity, cycle capacity retention rate and coulombic efficiency in Examples 1 to 19 are higher than those in Comparative Examples 1-3, indicating that the present disclosure can reduce the nucleation overpotential and polarization potential of sodium deposition, and improve the uniformity and consistency of sodium deposition by providing a multifunctional additive having sodium affinity, sodium replenishment and sodium storage functions in the functional layer. It has high density and can also play a role in replenishing sodium when the overall sodium content of the battery is reduced. It can also store sodium ions through alloying reactions.
  • the sodium deposition potential and polarization potential in Examples 1 to 19 are lower than those in Comparative Examples 1 to 3, and the initial discharge specific capacity, cycle capacity retention, and coulombic efficiency in Examples 1 to 19 are all higher than those in Comparative Examples 1 to 3.
  • the present disclosure by providing a multifunctional additive having sodium affinity, sodium replenishment, and sodium storage functions in the functional layer, can reduce the nucleation overpotential and polarization potential of sodium deposition, improve the uniformity and density of sodium deposition, and can also play a sodium replenishment function when the overall sodium content of the battery decreases, and can also store sodium ions through alloying reactions.
  • the present disclosure can reduce the nucleation overpotential and polarization potential of sodium deposition by adjusting the content of the multifunctional additive, thereby improving the cycle life and coulombic efficiency of the battery.
  • Examples 6 to 8 compared with Example 5 if the content of the multifunctional additive is too low, the sodium affinity, sodium replenishment, and sodium storage effects of the multifunctional additive will be reduced to a certain extent, reducing the cycle life and coulombic efficiency of the battery; as can be seen from Examples 6 to 8 compared with Example 9, if the content of the multifunctional additive is too high, the multifunctional additive is non-conductive and will increase the polarization potential to a certain extent, affecting the transport of electrons by the negative electrode current collector and affecting the reversibility of the sodium deposition/stripping process.
  • the present disclosure can increase the content of the multifunctional additive on the negative electrode current collector by adjusting the thickness of the functional layer, thereby improving the sodium affinity, sodium replenishment, and sodium storage effects of the multifunctional additive, and improving the cycle life and coulombic efficiency of the battery.
  • the thickness of the functional layer is too thin, the content of the multifunctional additive on the functional layer is low, which will reduce the cycle capacity retention rate and coulombic efficiency of the battery to a certain extent.
  • the thickness of the functional layer is too thick, the electron/ion transmission distance is increased, which will affect the reversibility of sodium deposition/stripping to a certain extent.
  • first and second are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as “first” or “second” may explicitly or implicitly include one or more of the features.
  • plural means two or more, unless otherwise specifically defined.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Composite Materials (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)
  • Cell Electrode Carriers And Collectors (AREA)

Abstract

一种负极集流体及其制备方法、钠二次电池、用电设备。负极集流体包括基材；功能层，功能层设置在基材的至少一侧，功能层包括多功能添加剂，多功能添加剂包括Na xMN y•zH 2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0＜x≤5，0＜y≤5，0≤z≤5。

Description

负极集流体及其制备方法、钠二次电池、用电设备
优先权信息
本公开请求2024年2月7日向中国国家知识产权局提交的专利申请202410171660X的优先权和权益，并且通过参照将其全文并入此处。
技术领域
本公开涉及电池技术领域，具体地，本公开涉及负极集流体及其制备方法、钠二次电池、用电设备。
背景技术
由于钠资源丰富，钠离子电池已经被视为锂电在低成本领域的重要补充。然而，钠离子电池当前的整体能量密度较小，远低于锂离子电池。由于金属钠的理论比容量较高，采用金属钠作为负极是提高能量密度的有效方案。无负极钠电在首次充放电时，会在负极集流体上沉积形成金属钠，沉积过程中，钠沉积不均匀，容易在负极集流体表面无序生长钠枝晶，增加破坏电解质界面膜的风险，降低电池的循环寿命。
发明内容
本公开旨在至少在一定程度上解决相关技术中的技术问题之一。
为此，本公开一方面提供了一种负极集流体，所述负极集流体包括基材；功能层，所述功能层设置在所述基材的至少一侧，所述功能层包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。由此，多功能添加剂同时具有亲钠、补钠和储钠能力，可以降低钠沉积的形核过电位，提高钠沉积的均匀性，当正负极之间可逆存储的钠离子总量减少时，多功能添加剂可以发挥补钠效果，提高电池的库伦效率和循环寿命，多功能添加剂还可以存储钠离子，发挥储钠作用，提高电池的比容量。
本公开第二方面提供了一种制备本公开第一方面的负极集流体的方法，包括在所述基材的至少一侧形成功能层，所述功能层包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。由此，该方法制备的负极集流体上具有多功能添加剂，多功能添加剂同时具有亲钠、补钠和储钠能力，可以降低钠沉积的形核过电位，提高钠沉积的均匀性，当正负极之间可逆存储的钠离子总量减少时，多功能添加剂可以发挥补钠效果，提高电池的库伦效率和循环寿命，多功能添加剂还可以存储钠离子，发挥储钠作用，提高电池的比容量。
本公开第三方面提供了一种钠二次电池，包括本公开第一方面提供的负极集流体或本公开第二方面提供的方法制备的负极集流体，所述钠二次电池在首次充放电后在所述功能层远离所述基材的一侧沉积形成金属钠。由此，可以提高钠二次电池的库伦效率、循环寿命和比容量。
本公开第四方面提供了一种用电设备，包括本公开第三方面提供的钠二次电池。
本公开的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本公开的实践了解到。
附图说明
本公开的上述和/或附加的方面和优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1显示了本公开一个实施例的负极集流体的结构示意图。
附图标记：
10：负极集流体；11：基材；12：功能层。
发明详细描述
下面详细描述本公开的实施例。下面描述的实施例是示例性的，仅用于解释本公开，而不能理解为 对本公开的限制。
此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在本公开的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。
在本公开的一个方面，提供了一种负极集流体，参考图1，所述负极集流体10包括基材11；功能层12，所述功能层12设置在所述基材11的至少一侧，所述功能层12包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。由此，多功能添加剂具有亲钠、补钠和储钠能力，可以降低钠沉积的形核过电位，提高钠沉积的均匀性，当正负极之间可逆存储的钠离子总量减少时，多功能添加剂可以发挥补钠效果，提高电池的库伦效率和循环寿命，多功能添加剂还可以存储钠离子，发挥储钠作用，提高电池的比容量。
下面对本公开能够实现上述有益效果的原理进行详细说明：
本公开提出的负极集流体10上包括功能层12，功能层12包括多功能添加剂NaxMNy*zH2O，其中，Na组分可以在电池充放电过程中发挥“蓄钠池”的功能，在电池总体钠含量降低时释放钠离子，发挥补钠的功能，提高电池的库伦效率。M组分本征亲钠，容易与钠离子反应形成亲钠合金(例如Na-Sn合金、Na-Zn合金)，从而降低负极集流体上钠沉积的形核过电位及钠沉积/剥离极化电势，提高钠沉积的均匀性和致密性，降低产生钠枝晶的概率，降低隔膜被钠枝晶刺穿导致电池短路的风险，提高电池的循环寿命；除此之外，M组分还可以通过合金化反应存储大量钠离子(例如形成Na15Sn4、Na3Bi等)，发挥储钠作用，提高电池的比容量。N组分可以进一步提高多功能添加剂的稳定性，降低多功能添加剂被氧化分解的风险。
根据本公开的一些实施例，功能层12设置在基材11的至少一个表面上。
根据本公开的一些实施例，M包括Sn原子、Sb原子、Bi原子、Zn原子中的至少一种，N包括O原子、S原子、Se原子中的至少一种。由此，Sn原子、Sb原子、Bi原子、Zn原子本征亲钠，可以降低负极集流体上钠沉积的形核过电位及钠沉积/剥离极化电势，提高钠沉积的均匀性和致密性，降低产生钠枝晶的概率，降低隔膜被钠枝晶刺穿导致电池短路的风险，提高电池的循环寿命；除此之外，Sn原子、Sb原子、Bi原子、Zn原子还可以通过合金化反应存储大量钠离子(例如形成Na15Sn4、Na3Bi等)，发挥储钠作用，提高电池的比容量。O原子、S原子、Se原子可以进一步提高多功能添加剂的稳定性，降低多功能添加剂被氧化分解的风险。
根据本公开的一些实施例，M包括Sn原子，N包括O原子、S原子中的至少一种。当M包括Sn原子时，一个Sn离子可以结合3-4个Na+，可以进一步提高亲钠和储钠能力，提高钠沉积的均匀性和致密性，提高电池的库伦效率和循环寿命，提高电池的比容量。当N包括O原子、S原子中的至少一种时，可进一步提高多功能添加剂的稳定性，降低多功能添加剂被氧化分解的风险。
根据本公开的一些具体实施例，所述多功能添加剂包括Na2SnO3*3H2O、Na2ZnO2、Na3SbS4、NaBiO3中的至少一种。由此，上述种类的多功能添加剂同时具有亲钠、补钠和储钠功能。具体地，上述多功能添加剂中的Na组分可以在电池充放电过程中发挥“蓄钠池”的功能，在电池总体钠含量降低时释放钠离子，发挥补钠的功能，提高电池的库伦效率。Sn离子、Zn离子、Sb离子和Bi离子本征亲钠，容易与钠离子反应形成亲钠合金(例如Na-Sn合金、Na-Zn合金、Na-Sb合金、Na-Bi合金)，从而降低负极集流体10上钠沉积的形核过电位及钠沉积/剥离极化电势，提高钠沉积的均匀性和致密性，降低产生钠枝晶的概率，降低隔膜被钠枝晶刺穿导致电池短路的风险，提高电池的循环寿命；除此之外，Sn离子、Zn离子、Sb离子和Bi离子还可以通过合金化反应存储大量钠离子(例如形成Na15Sn4、Na3Bi等)，发挥储钠作用，提高电池的比容量。O原子和S原子可以进一步提高多功能添加剂的结构稳定性，降低多功能添加剂被氧化分解的风险。
根据本公开的一些实施例，基于所述功能层12的总质量，所述多功能添加剂的质量占比可以为1％-10％。例如，可以为1％、2％、3％、4％、5％、6％、7％、8％、9％或10％等，或可以为上述任意数值组成的范围。由此，提高多功能添加剂在功能层12的质量占比，在功能层12上形成更多、更均匀分布的亲钠、补钠和储钠位点，进一步提高功能层12各区域的亲钠、补钠和储钠能力的均一性，从而提 高沉积形成的钠金属层的均匀性，降低局部产生钠枝晶的概率，进而提高电池的库伦效率、循环寿命和比容量。如果多功能添加剂的含量过少，功能层上12形成的亲钠、补钠、储钠位点数量较少，会在一定程度上影响多功能添加剂对钠沉积/剥离过程的改善效果；如果不导电的双功能添加剂的含量过多，会在一定程度上影响负极集流体10上电子和离子的传输，降低钠沉积/剥离过程的可逆性。
根据本公开的一些实施例，功能层12中多功能添加剂可通过原子荧光光谱法、电感耦合等离子体质谱法、火焰原子吸收光谱等方法鉴定其存在以及含量。
根据本公开的一些实施例，所述功能层12的厚度可以为0.5μm-10μm。例如，可以为0.5μm、1μm、3μm、5μm、7μm、9μm或10μm等，或可以为上述任意数值组成的范围。由此，通过使功能层12的厚度在上述范围，可以增加亲钠、补钠、储钠位点的数量，从而提高钠沉积的均匀性。同时，提高电解液在负极集流体10上的传输速率，提高电解液对负极集流体10的浸润性。通过使功能层12的厚度在上述范围，还可以降低因功能层12太厚而发生功能层12脱落的风险。如果功能层12的厚度过低，基材表面的亲钠、补钠、储钠位点的数量较少，影响钠沉积的均匀性，进而影响其电化学性能；如果功能层12的厚度过高，即功能层12表面至基材11表面的距离较大，会增加电子/离子传输距离，影响电池的快速钠沉积/剥离；而且，功能层12的厚度过大，会在一定程度上降低功能层12和基材11之间的结合力，增加了功能层12发生脱落和电解液浸润性差的风险。
根据本公开的一些实施例，所述功能层12还包括碳主材和粘结剂中的至少一种。由此，碳主材可以为多功能添加剂提供均匀、稳定的负载位点，以在功能层12上形成均匀分布的多功能添加剂，进一步提高功能层各个区域钠沉积的均匀性，提高功能层12与基材11之间的粘结力，降低功能层12发生脱落的风险。
根据本公开的一些实施例，所述负极集流体10满足以下条件的至少之一：基于所述功能层12的总质量，所述碳主材的质量占比为60％-90％；基于所述功能层12的总质量，所述粘结剂的质量占比为5％-30％。由此，碳主材为多功能添加剂提供稳定的负载位点，通过使碳主材含量在上述范围，可在功能层12上形成更多的双功能添加剂的负载位点，通过使粘结剂的含量在上述范围，可进一步提高功能层12与基材11之间的粘结力，降低功能层12发生脱落的风险。
根据本公开的一些实施例，所述功能层12还可以包括碳主材。碳主材可以为多功能添加剂提供均匀、稳定的负载位点，从而可以提高多功能添加剂在功能层12分布的均匀性，提高功能层12各区域的亲钠、补钠和储钠能力的均一性，进而提高钠沉积的均匀性，降低局部产生钠枝晶的概率，进而提高电池的库伦效率、循环寿命和比容量。
根据本公开的一些具体实施例，基于所述功能层12的总质量，所述碳主材的质量占比为60％-90％，例如，可以为60％、65％、70％、75％、80％、85％或90％等，或可以为上述任意数值组成的范围。由此，通过使碳主材的质量占比在上述范围，可以在基材11表面为多功能添加剂提供更多、更均匀的负载位点，从而提高多功能添加剂在功能层12分布的均匀性，提高功能层12各区域亲钠能力的均一性，进而提高钠沉积的均匀性，提高电池的循环寿命。如果碳主材的含量过低，导致功能层12中其他不导电的材料的含量过多，会在一定程度上降低负极集流体10的电子传输能力，降低钠沉积/剥离过程的可逆性。
作为示例，所述碳主材包括炭黑、碳纤维、碳纳米管、石墨烯中的至少一种。
根据本公开的一些实施例，所述功能层12还可以包括粘结剂。由此，提高功能层12和基材11之间的粘结力，防止功能层12发生脱落。
根据本公开的一些具体实施例，基于所述功能层12的总质量，所述粘结剂的质量占比为5％-30％。例如，可以为5％、10％、15％、20％、25％或30％等，或可以为上述任意数值组成的范围。由此，提高功能层12与基材11之间的粘结力，降低功能层12脱落的风险。根据本公开的一些具体实施例，基于所述功能层12的总质量，所述粘结剂的质量占比可以为10％-20％。如果粘结剂的含量过高，不导电的粘结剂会在一定程度上影响功能层12中的电子/离子的传输，影响钠沉积/剥离过程；如果粘结剂的含量过低，会降低功能层12与基材11之间的粘结力，增加功能层12发生脱落的风险。
根据本公开的一些具体实施例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚丙烯腈、聚酰亚胺、羧甲基纤维素钠(CMC-Na)、丁苯橡胶、聚丙烯酸钠、海藻酸钠、聚四氟乙烯、聚乙烯醇中的至少一种。
根据本公开的一些实施例，所述功能层12包括多功能添加剂、碳主材和粘结剂。具体地，所述负极集流体10的制备方法可以包括：将所述多功能添加剂、所述碳主材和所述粘结剂与溶剂混合形成浆料，将所述浆料形成在所述基材11的至少一个表面上，干燥，以形成功能层12。
作为示例，形成浆料的过程中可通过机械搅拌或球磨搅拌，以提高浆料的均匀性。
作为示例，当钠二次电池为钠金属电池时，负极集流体10的基材11可以为钠金属。
作为示例，当钠二次电池为无负极钠电池时，负极集流体10的基材11可以为金属箔材、多孔金属板或复合集流体。复合集流体可包括高分子材料基层和形成于高分子材料基材11至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材11(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE))等的基材11上而形成。
根据本公开的一些具体实施例，负极集流体10的基材11可以为铝。
本公开第二方面提供了一种制备本公开第一方面的负极集流体10的方法，包括：在所述基材11的至少一侧形成功能层12，所述功能层12包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。
根据本公开的一些实施例，所述方法还可以包括：将碳主材、多功能添加剂和第一溶剂混合，干燥，然后进行热处理，以得到混合物；将所述混合物、粘结剂和第二溶剂混合形成浆料，将所述浆料形成在所述基材11的至少一侧，干燥，以形成所述功能层12。由此，提高多功能添加剂在碳主材中的附着力，提高多功能添加剂与碳主材混合的均匀性，提高功能层12各个区域钠沉积的均匀性。具体地，可以将碳主材、多功能添加剂和水混合，使碳主材和多功能添加剂在水中混合均匀，干燥除去第一溶剂后，进行高温热处理，提高多功能添加剂和碳主材之间的附着力，将混合物与粘结剂、第二溶剂形成浆料，形成在基材11的至少一侧，干燥后即可形成多功能添加剂分布均匀、不易脱落的功能层12。
作为示例，所述浆料可以通过滚涂、刷涂、喷涂等方式涂覆在基材11的至少一个表面上。
根据本公开的一些实施例，所述热处理的温度可以为100℃-800℃。例如，可以为100℃、200℃、300℃、400℃、500℃、600℃、700℃或800℃，或可以为上述任意数值组成的范围。由此，通过将碳主材和多功能添加剂在此温度范围内进行混合，可以提高碳主材和多功能添加剂之间的附着力，提高多功能添加剂在碳主材中分布的均匀性，进而提高功能层各个区域的多功能添加剂分布的均匀性，使功能层各个区域具有均一的亲钠、补钠和储钠能力，提高钠沉积的均匀性。根据本公开的一些具体实施例，所述热处理的温度可以为400℃-600℃。
本公开第三方面提供了一种钠二次电池，包括本公开第一方面提供的负极集流体10，或本公开第二方面提供的方法制备的负极集流体10，所述钠二次电池在首次充放电后在功能层12远离基材11的一侧沉积形成金属钠。由此，可以提高钠二次电池的库伦效率、循环寿命和比容量。
作为示例，钠二次电池可以为钠金属电池或无负极钠电池。
根据本公开的一些实施例，钠二次电池还包括正极极片和隔膜，隔膜设置在正极极片和负极集流体之间。
正极极片包括正极集流体和形成在正极集流体上的正极活性材料层，正极活性材料层包括正极活性物质、正极粘结剂和正极导电剂。在本公开的实施例中，正极集流体可以采用具有良好导电性及机械强度的材质，优选为铝箔。
在本公开的实施例中，正极活性物质的具体种类均不受特别限定，本领域人员可根据实际需求进行选择，作为一些具体示例，正极活性物质包括磷酸钒钠、氟磷酸钒钠、磷酸铁钠、焦磷酸铁钠和复合磷酸铁钠中的至少一种。
在本公开的实施例中，正极导电剂的具体种类并不受特别限定，本领域人员可根据实际需求进行选择，作为一些具体示例，正极导电剂包括石墨、超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
同样地，正极粘结剂的具体种类并不受特别限定，本领域人员可根据实际需求进行选择，作为一些具体示例，正极粘结剂包括聚偏氟乙烯(PVDF)及聚四氟乙烯(PTFE)中的至少一种。
正极极片的制备方法包括：按照预设比例将正极活性物质、正极粘结剂和正极导电剂混合均匀，加入溶剂搅拌均匀形成正极浆料，然后涂布到集流体上，烘干，最后根据电池外壳的不同，切成特定形状的正极极片备用。
本公开第四方面提供了一种用电设备，包括本公开第三方面提供的钠二次电池。
具体地，上述用电设备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。
下面详细描述本公开的实施例，需要说明的是下面描述的实施例是示例性的，仅用于解释本公开，而不能理解为对本公开的限制。另外，如果没有明确说明，在下面的实施例中所采用的所有试剂均为市场上可以购得的，或者可以按照本文或已知的方法合成的，对于没有列出的反应条件，也均为本领域技术人员容易获得的。
实施例1
1、制备负极集流体
将碳主材、多功能添加剂、水按照质量比67:8:100的比例混合，机械搅拌2h使其混合均匀，混合均匀后烘干其中的水分，再转移至氮气保护的管式炉中，升温至500℃后热处理3h，将热处理产物与粘结剂按照质量比75:25的比例混合，再加入一定量的溶剂(氮甲基吡咯烷酮)后搅拌成均匀的浆料，浆料固含量为10％，使用涂布机将浆料涂布在铝箔上，并在烘箱中烘干，通过辊压机对集流体进行冷压得到功能层，功能层厚度为8μm。
2、制备正极极片
将活性材料(磷酸钒钠)、导电剂(科琴黑)、粘结剂(PVDF)按照质量比为90:3:7的比例在搅拌装置中混合均匀，再加入一定量溶剂(氮甲基吡咯烷酮)后搅拌形成均匀的浆料，浆料固含量为40％，使用涂布机将浆料涂布在正极集流体铝箔上烘干、冷压，以得到正极极片。
3、配制电解液
在氩气保护的手套箱中，取1L的二乙二醇二甲醚于容量瓶中；称取168g六氟磷酸钠，溶于上述溶剂中；充分搅拌至钠盐完全溶解，即获得所需电解液。
4、隔膜
以16μm的聚乙烯薄膜为隔膜。
5、组装半电池
使用圆孔型切片机将正极极片、负极集流体、隔膜分别冲切成不同直径的小圆片；将负极集流体、隔膜、金属钠片按顺序放入纽扣电池壳中，且隔膜处于负极集流体和金属钠片中间，加上上述电解液，组装成纽扣半电池。
6、组装全电池
将正极极片、隔膜、负极集流体按顺序叠放，且隔膜处于正极极片和负极集流体中间，加上上述电解液，组装成全电池。
实施例2-实施例19、对比例1-对比例3中的电池的制备方法同实施例1，区别详见表1。
表1
性能测试
1、形核过电位和极化电势的测试方法
在电池充放电测试仪上对半电池进行恒流充放电测试；充放电电流均设置为2mA/cm2，放电截止容量设置为2mAh/cm2，充电截止电压设置为1.5V；绘制电池的第10圈充放电曲线，读取其钠形核过电位，即为负极集流体钠沉积形核过电位；绘制电池的第10圈充放电曲线，计算其充放电极化电势，即为负极集流体的极化电势。
2、首次放电比容量的测试方法
在电池充放电测试仪上对全电池进行恒流充放电测试；基于正极活性物质质量，充放电电流密度设置为100mA/g，充放电电压范围设置为2.5V-3.8V。第1圈的放电比容量即为电池首次放电比容量。
3、100圈循环容量保持率的测试方法
在电池充放电测试仪上对全电池进行恒流充放电测试；基于正极活性物质质量，充放电电流密度设置为100mA/g，充放电电压范围设置为2.5V-3.8V。第100圈/第1圈放电比容量的比值即为100圈循环容量保持率。
4、100圈平均库伦效率的测试方法
在电池充放电测试仪上对全电池进行恒流充放电测试；基于正极活性物质质量，充放电电流密度设置为100mA/g，充放电电压范围设置为2.5V-3.8V。第1圈至第100圈库伦效率的平均值即为100圈平均库伦效率。
5、功能层厚度的测试方法
取上述实施例使用的光箔，使用测厚仪测量其厚度(T0)；取上述实施例制备得到的双面涂布功能涂层的负极集流体，使用测厚仪测量其厚度(T1)；则功能层厚度的T2＝(T1-T0)/2。
实施例1-实施例19、对比例1-对比例3中的电池的测试结果见表2。
表2
由表1和表2可以看出，对比例1中的负极集流体上不包括功能层，对比例2中的负极集流体设置有功能层，但是功能层未设置有多功能添加剂，对比例3中的负极集流体上设置有功能层且功能层上设置有添加剂，但是添加剂与本公开的多功能添加剂的种类不同，实施例1-实施例19的负极集流体上均设置有功能层，且功能层均包括同时具有亲钠、补钠和储钠功能的多功能添加剂。由测试结果可以看出，实施例1-实施例19中的钠沉积电位和极化电势均低于对比例1-3，实施例1-实施例19中的首次放电比容量、循环容量保持率和库伦效率均高于对比例1-3，说明本公开通过在功能层中设置同时具有亲钠、补钠和储钠功能的多功能添加剂，可以降低钠沉积的形核过电位和极化电势，提高钠沉积的均匀性和致 密性，还可以在电池总体钠含量降低时发挥补钠功能，还可以通过合金化反应储存钠离子。
由表1和表2可以看出，对比例1中的负极集流体上不包括功能层，对比例2中的负极集流体设置有功能层，但是功能层未设置有多功能添加剂，对比例3中的负极集流体上设置有功能层且功能层上设置有添加剂，但是添加剂与本公开的多功能添加剂的种类不同，实施例1-实施例19的负极集流体上均设置有功能层，且功能层均包括同时具有亲钠、补钠和储钠功能的多功能添加剂。由测试结果可以看出，实施例1-实施例19中的钠沉积电位和极化电势均低于对比例1-3，实施例1-实施例19中的首次放电比容量、循环容量保持率和库伦效率均高于对比例1-3，说明本公开通过在功能层中设置同时具有亲钠、补钠和储钠功能的多功能添加剂，可以降低钠沉积的形核过电位和极化电势，提高钠沉积的均匀性和致密性，还可以在电池总体钠含量降低时发挥补钠功能，还可以通过合金化反应储存钠离子。
由实施例1-实施例4与对比例3相比可以看出，对比例3中添加剂不是本公开中的同时具有储钠、补钠和亲钠功能的添加剂，所以对比例3中的形核过电位较高，首次放电比容量、循环容量保持率和库伦效率较低，实施例1-实施例4中的多功能添加剂同时具有补钠、储钠和亲钠能力，所以可以提高电池的循环容量保持率和库伦效率。
由实施例5-实施例9可以看出，本公开通过调整多功能添加剂的含量，可以降低钠沉积的形核过电位和极化电势，提高电池的循环寿命和库伦效率。由实施例6-实施例8与实施例5相比可以看出，如果多功能添加剂的含量过少，会在一定程度上降低多功能添加剂的亲钠、补钠和储钠效果，降低电池的循环寿命和库伦效率；由实施例6-8与实施例9相比可以看出，如果多功能添加剂的含量过多，多功能添加剂不导电，会在一定程度上增加极化电势，影响负极集流体对电子的传输，影响钠沉积/剥离过程的可逆性。
由实施例10-实施例14可以看出，本公开通过调整功能层的厚度，可以提高负极集流体上多功能添加剂的含量，从而提高多功能添加剂的亲钠、补钠和储钠效果，提高电池的循环寿命和库伦效率。由实施例11-实施例13与实施例10相比可以看出，如果功能层的厚度太薄，功能层上多功能添加剂的含量较少，会在一定程度上降低电池的循环容量保持率和库伦效率。由实施例11-实施例13与实施例14相比可以看出，如果功能层的厚度太厚，增加了电子/离子传输距离，会在一定程度上影响钠沉积/剥离的可逆性。
由实施例15-实施例19可以看出，本公开通过对多功能添加剂和碳主材进行热处理，可以提高碳主材和多功能添加剂混合的均匀性，提高多功能添加剂和碳主材之间的附着力，进而提高电池的循环性能和库伦效率。由实施例16-19与实施例15相比可以看出，如果热处理的温度较低，会在一定程度上影响碳主材和多功能添加剂混合的均匀性，降低电池的循环容量保持率和库伦效率。
在本公开的描述中，需要理解的是，术语“中心”、“纵向”、“横向”、“长度”、“宽度”、“厚度”、“上”、“下”、“前”、“后”、“左”、“右”、“竖直”、“水平”、“顶”、“底”“内”、“外”、“顺时针”、“逆时针”、“轴向”、“径向”、“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本公开和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本公开的限制。
此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本公开的描述中，“多个”的含义是两个或两个以上，除非另有明确具体的限定。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本公开的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。
尽管上面已经示出和描述了本公开的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本公开的限制，本领域的普通技术人员在本公开的范围内可以对上述实施例进行变化、修改、替换和变型。

Claims (14)

  1. 一种负极集流体，其中，包括：
    基材；
    功能层，所述功能层设置在所述基材的至少一侧，所述功能层包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。
  2. 根据权利要求1所述的负极集流体，其中，M包括Sn原子、Sb原子、Bi原子、Zn原子中的至少一种，N包括O原子、S原子、Se原子中的至少一种。
  3. 根据权利要求2所述的负极集流体，其中，M包括Sn原子，N包括O原子、S原子中的至少一种。
  4. 根据权利要求3所述的负极集流体，其中，所述多功能添加剂包括Na2SnO3*3H2O、Na2ZnO2、Na3SbS4、NaBiO3中的至少一种。
  5. 根据权利要求4所述的负极集流体，其中，基于所述功能层的总质量，所述多功能添加剂的质量占比为1％-10％。
  6. 根据权利要求1-5任一项所述负极集流体，其中，所述功能层的厚度为0.5μm-10μm。
  7. 根据权利要求6所述的负极集流体，其中，所述功能层还包括碳主材和粘结剂中的至少一种。
  8. 根据权利要求7所述负极集流体，其中，满足以下条件的至少之一：
    基于所述功能层的总质量，所述碳主材的质量占比为60％-90％；
    基于所述功能层的总质量，所述粘结剂的质量占比为5％-30％。
  9. 根据权利要求8所述负极集流体，其中，满足以下条件的至少之一：
    所述碳主材包括炭黑、碳纤维、碳纳米管、石墨烯中的至少一种；
    所述粘结剂包括聚偏氟乙烯、聚丙烯腈、聚酰亚胺、羧甲基纤维素钠、丁苯橡胶、聚丙烯酸钠、海藻酸钠、聚四氟乙烯、聚乙烯醇中的至少一种。
  10. 一种制备权利要求1-9任一项所述的负极集流体的方法，其中，包括：
    在所述基材的至少一侧形成功能层，所述功能层包括多功能添加剂，所述多功能添加剂包括NaxMNy*zH2O，其中，M包括可与Na形成合金的原子，N包括O原子、S原子、Se原子中的至少一种，0<x≤5，0<y≤5，0≤z≤5。
  11. 根据权利要求10所述的方法，其中，将碳主材、多功能添加剂和第一溶剂混合，干燥，然后进行热处理，以得到混合物；
    将所述混合物、粘结剂和第二溶剂混合形成浆料，将所述浆料形成在所述基材的至少一侧，干燥，以形成所述功能层。
  12. 根据权利要求11所述的方法，其中，所述热处理的温度为100℃-800℃。
  13. 一种钠二次电池，其中，包括权利要求1-9任一项所述的负极集流体或权利要求10-12任一项所述的方法制备的负极集流体，所述钠二次电池在首次充放电后在所述功能层远离所述基材的一侧沉积形成金属钠。
  14. 一种用电设备，其中，包括权利要求13所述的钠二次电池。
PCT/CN2024/133177 2024-02-07 2024-11-20 负极集流体及其制备方法、钠二次电池、用电设备 Pending WO2025167263A1 (zh)

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Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117727948B (zh) * 2024-02-07 2024-05-14 深圳海辰储能科技有限公司 负极集流体及其制备方法、钠二次电池、用电设备
CN120453578A (zh) * 2024-02-08 2025-08-08 宁德时代新能源科技股份有限公司 钠二次电池、正极极片、补钠添加剂和用电装置
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190280326A1 (en) * 2018-03-09 2019-09-12 The Regents Of The University Of California Interlayer sodium electrodes for sodium ion batteries
CN113437254A (zh) * 2021-06-26 2021-09-24 宁德时代新能源科技股份有限公司 钠离子电池的负极极片、电化学装置及电子设备
CN114551798A (zh) * 2020-11-26 2022-05-27 本田技研工业株式会社 锂离子二次电池用负极
CN115763801A (zh) * 2022-10-24 2023-03-07 杭州华宇新能源研究院有限公司 一种固态钠离子电池
CN117727948A (zh) * 2024-02-07 2024-03-19 深圳海辰储能科技有限公司 负极集流体及其制备方法、钠二次电池、用电设备

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5721068A (en) * 1995-07-14 1998-02-24 Rayovac Corporation Electrochemical cell, gelled anode, and coated current collector therefor
CN102916186B (zh) * 2012-11-07 2015-07-01 深圳华粤宝电池有限公司 一种钠离子电池负极材料和负极的制备方法及钠离子电池
CN111293290B (zh) * 2018-12-10 2021-06-04 中南大学 富钠过渡金属氧化物复合补钠正极活性材料、正极材料、正极及其制备和在钠电中的应用
CN109888193B (zh) * 2019-01-14 2021-02-19 厦门大学 一种提高钠金属负极电沉积和溶出可逆性的方法
US20220069313A1 (en) * 2020-08-28 2022-03-03 Global Graphene Group, Inc. Graphene-protected lithiophilic or nathiophilic metal anode for an alkali metal battery
CN113451546B (zh) * 2021-06-26 2022-05-06 宁德时代新能源科技股份有限公司 钠金属电池、电化学装置
CN114388740A (zh) * 2022-01-13 2022-04-22 江西安驰新能源科技有限公司 一种全固态锂离子电池用复合正极及其极片的制备方法
CN218274641U (zh) 2022-03-17 2023-01-10 上海桔晟科技有限公司 复合钠片、电池及用电装置
CN114843524A (zh) 2022-06-17 2022-08-02 珠海冠宇电池股份有限公司 一种改性集流体及包括该改性集流体的无负极钠金属电池
CN115233020B (zh) * 2022-08-08 2023-04-21 深圳海润新能源科技有限公司 钠锡合金、负极及其制备方法、电池及电池包
US11760651B1 (en) * 2022-10-18 2023-09-19 Unigrid, Inc. Electrodes, electrode materials, and manufacturing thereof
CN115548262A (zh) * 2022-11-02 2022-12-30 欣旺达电子股份有限公司 一种负极极片、二次电池及用电设备
CN115700935A (zh) * 2022-11-10 2023-02-07 宜宾南木纳米科技有限公司 正极集流体固态电解质涂层、正极极片及制备方法和应用
CN116021007B (zh) * 2022-12-25 2025-12-19 复旦大学 一种钠离子电池负极预钠化剂及其制备方法和应用
CN116825960A (zh) 2023-05-15 2023-09-29 浙江大学 一种抑制析钠的改性碳负极极片及其制备方法和应用
CN220400629U (zh) * 2023-07-05 2024-01-26 深圳珈钠能源科技有限公司 一种预钠化的钠离子电池负极片
CN116995192A (zh) * 2023-08-04 2023-11-03 河南省氟基新材料科技有限公司 一种补钠正极极片及其制备方法和钠离子电池
CN117317239A (zh) 2023-09-08 2023-12-29 新疆汉行科技有限公司 一种无负极钠金属电池的复合集流体及制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190280326A1 (en) * 2018-03-09 2019-09-12 The Regents Of The University Of California Interlayer sodium electrodes for sodium ion batteries
CN114551798A (zh) * 2020-11-26 2022-05-27 本田技研工业株式会社 锂离子二次电池用负极
CN113437254A (zh) * 2021-06-26 2021-09-24 宁德时代新能源科技股份有限公司 钠离子电池的负极极片、电化学装置及电子设备
CN115763801A (zh) * 2022-10-24 2023-03-07 杭州华宇新能源研究院有限公司 一种固态钠离子电池
CN117727948A (zh) * 2024-02-07 2024-03-19 深圳海辰储能科技有限公司 负极集流体及其制备方法、钠二次电池、用电设备

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