WO2024250666A1 - 二次电池以及包括该二次电池的用电装置 - Google Patents

二次电池以及包括该二次电池的用电装置 Download PDF

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WO2024250666A1
WO2024250666A1 PCT/CN2024/070506 CN2024070506W WO2024250666A1 WO 2024250666 A1 WO2024250666 A1 WO 2024250666A1 CN 2024070506 W CN2024070506 W CN 2024070506W WO 2024250666 A1 WO2024250666 A1 WO 2024250666A1
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Prior art keywords
negative electrode
film layer
electrode film
optionally
secondary battery
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English (en)
French (fr)
Inventor
吴凯
严观福生
靳超
钟铭
吴子睿
代志鹏
张鑫
郑仕兵
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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Priority to EP24818205.7A priority Critical patent/EP4657571A4/en
Publication of WO2024250666A1 publication Critical patent/WO2024250666A1/zh
Priority to US19/300,268 priority patent/US20250379232A1/en
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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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • 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 a secondary battery and an electrical device comprising the secondary battery.
  • secondary batteries have been widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields. As secondary batteries have made great progress, higher requirements have been placed on their performance.
  • the present application is made in view of the above-mentioned problems, and an object of the present application is to provide a secondary battery and an electric device including the secondary battery, wherein the secondary battery has high storage performance.
  • the first aspect of the present application provides a secondary battery, including a negative electrode plate, the negative electrode plate includes a negative electrode collector and a negative electrode film layer arranged on at least one surface of the negative electrode collector, and the negative electrode film layer includes an additive capable of undergoing a nucleophilic reaction with a cyclic carbonate compound.
  • the storage performance of the secondary battery of the present application is improved by making the negative electrode film layer include an additive capable of undergoing a nucleophilic reaction with the cyclic carbonate compound.
  • the additive includes at least one of a sulfur-containing substance, a selenium-containing substance, a composite of a sulfur-containing substance and a carbon-based material, a composite of a selenium-containing substance and a carbon-based material, a sulfur-containing substance with a carbon coating, and a selenium-containing substance with a carbon coating;
  • the sulfur-containing substance includes at least one of elemental sulfur, lithium sulfide, and sodium sulfide;
  • the selenium-containing substance includes at least one of elemental selenium, lithium selenide, sodium selenide, cobalt selenide, and nickel selenide;
  • the carbon-based material includes a nano-carbon-based material and graphene, and optionally, the nano-carbon-based material includes a carbon nanotube.
  • the sulfur-containing substance and the selenium-containing substance undergo a reduction reaction during battery charging and discharging, undergo a nucleophilic reaction with a cyclic carbonate compound, and participate in the formation of an SEI film.
  • the conductivity and fast charging performance of the battery can be improved.
  • the mass proportion of the additive is less than or equal to 10%, and can be optionally 0.5%-5%.
  • the battery can obtain excellent conductivity and fast charging performance while achieving high storage performance.
  • the particle size Dv50 of the additive is 50nm-500nm, and can be optionally 100nm-200nm. By controlling the particle size within the above range, a larger specific surface area can be obtained, thereby increasing the reaction activity.
  • the negative electrode film layer includes a negative electrode active material, and the negative electrode active material includes a silicon-based material; optionally, the mass proportion of the silicon-based material in the negative electrode active material is greater than or equal to 5%, and more optionally 5%-25%; optionally, the silicon-based material includes at least one of silicon, silicon-carbon composite materials, and silicon-oxygen compounds.
  • the negative electrode film layer includes a first negative electrode film layer and a second negative electrode film layer, the second negative electrode film layer is arranged between the negative electrode current collector and the first negative electrode film layer, and the first negative electrode film layer and/or the second negative electrode film layer include additives.
  • the mass proportion of the additive in the first negative electrode film layer, is greater than 0% and less than or equal to 10%, and may be 0.5%-5%; in the second negative electrode film layer, the mass proportion of the additive is 0%-5%, and may be 0.1%-2%.
  • the first negative electrode film layer and the second negative electrode film layer both include additives, and the materials of the additives in the first negative electrode film layer and the second negative electrode film layer are the same or different.
  • the first negative electrode film layer and the second negative electrode film layer both include additives; In the first negative electrode film layer, the mass proportion of the additive is recorded as A1, and in the second negative electrode film layer, the mass proportion of the additive is recorded as A2; the secondary battery satisfies: A1/A2>1; optionally, 2 ⁇ A1/A2 ⁇ 10.
  • the first negative electrode film layer includes a first negative electrode active material
  • the second negative electrode film layer includes a second negative electrode active material
  • the first negative electrode active material and/or the second negative electrode active material include a silicon-based material
  • both the first negative electrode active material and the second negative electrode active material include a silicon-based material
  • the mass proportion of the silicon-based material in the first negative electrode active material is greater than the mass proportion of the silicon-based material in the second negative electrode active material.
  • the mass proportion of the silicon-based material in the first negative electrode active material is greater than or equal to 5%, and may be 5%-25%.
  • the first negative electrode active material and/or the second negative electrode active material further comprises a carbon material; optionally, the carbon material comprises graphite, and more optionally, high-density graphite with a powder pressure of more than 1.8 g/cm3.
  • the present application achieves better storage performance and conductivity for the secondary battery by configuring the double-layer negative electrode film layer.
  • the secondary battery includes a positive electrode plate, the positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, and the positive electrode film layer includes a lithium supplement; optionally, the lithium supplement includes at least one of lithium sulfide, lithium selenide, lithium oxide, and lithium nitride.
  • the lithium supplement includes at least one of lithium sulfide, lithium selenide, lithium oxide, and lithium nitride.
  • the secondary battery includes an electrolyte, and the electrolyte includes a cyclic carbonate compound; optionally, the cyclic carbonate compound includes at least one of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, vinylene carbonate, and butylene carbonate.
  • the cyclic carbonate compound undergoes a nucleophilic reaction with the additive in the negative electrode film layer, participates in the formation of the SEI film, and improves the storage performance of the secondary battery.
  • the negative electrode film layer includes both high-valent sulfur and low-valent sulfur, and/or, the negative electrode film layer includes both high-valent selenium and low-valent selenium; optionally, the high-valent sulfur includes at least one of +4-valent sulfur and +6-valent sulfur; optionally, the S2p spectrum peak of the high-valent sulfur is 168.5eV-171eV; optionally, the low-valent sulfur includes -2-valent sulfur to -1/6-valent sulfur, and optionally, the S2p spectrum peak of the low-valent sulfur is 161eV-166.5eV.
  • the high-valent selenium includes At least one of +4-valent selenium and +6-valent selenium; optionally, the Se3d peak of high-valent selenium is 58.9eV-61.2eV; optionally, low-valent selenium includes -2-valent selenium; optionally, the Se3d peak of low-valent selenium is 54eV-55.1eV.
  • a second aspect of the present application provides an electrical device, which includes the secondary battery of the first aspect of the present application.
  • a secondary battery having excellent storage performance and an electric device including the lithium ion battery can be provided.
  • FIG. 1 is a schematic diagram showing the structure of a negative electrode sheet in a secondary battery of the present application.
  • range disclosed in this application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range.
  • the range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range.
  • the “include” and “comprising” mentioned in this application are open-ended or closed-ended.
  • the “include” and “comprising” may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • a secondary battery is a battery that can be used continuously by recharging the active materials after the battery is discharged, such as a lithium-ion battery.
  • a secondary battery includes a positive electrode, a negative electrode, a separator and an electrolyte.
  • active ions such as lithium ions
  • the electrolyte is between the positive electrode and the negative electrode, and mainly plays the role of conducting active ions.
  • One embodiment of the present application provides a secondary battery, including a negative electrode plate, the negative electrode plate including a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector, the negative electrode film layer including an additive capable of undergoing a nucleophilic reaction with a cyclic carbonate compound.
  • the applicant unexpectedly discovered that when an additive capable of undergoing nucleophilic reaction with cyclic carbonate compounds is added to the negative electrode film layer, the additive reacts with the cyclic carbonate compounds in the electrolyte of the secondary battery, inducing the ring opening thereof to form a highly elastic PEO-like polymer, which participates in SEI formation and strengthens film formation, thereby reducing irreversible capacity loss caused by frequent repair of SEI rupture and consumption of active lithium; at the same time, a conductive network with high ionic conductivity is formed, which is beneficial to the migration of active ions (such as lithium ions, etc.) in the secondary battery, reduces charge transfer impedance and electrochemical polarization, reduces polarization capacity loss, and thus improves the storage performance of the battery.
  • active ions such as lithium ions, etc.
  • the additive as long as it can react with the cyclic carbonate compound by nucleophilic reaction, there is no particular limitation.
  • sulfur-containing substances and/or selenium-containing substances are included, for example, including at least one of elemental sulfur, lithium sulfide, sodium sulfide, selenium-containing elemental substances, lithium selenide, sodium selenide, cobalt selenide, and nickel selenide.
  • These additives undergo reduction reaction during the charge and discharge process of the battery, and further react with the cyclic carbonate electrolyte solvent.
  • lithium sulfide reacts with ethylene carbonate to generate poly (ethylene oxide) (PEO)-type polymers, which participate in the formation of SEI film.
  • PEO poly (ethylene oxide)
  • a carbon-based material is used as a substrate, and a sulfur-containing substance and/or a selenium-containing substance is loaded on the carbon-based material to form a composite.
  • the carbon-based material includes a nano-carbon-based material, graphene, etc.
  • the nano-carbon-based material is a carbon nanotube.
  • carbon can also be used as a coating material.
  • nanoporous carbon is used as a coating material to coat the surface of the above-mentioned sulfur-containing substance and/or selenium-containing substance to form a sulfur-containing substance with a carbon coating layer and a selenium-containing substance with a carbon coating layer. In this way, while improving the storage performance of the battery, the conductivity and fast charging performance of the battery can be improved. In addition, the amount of the negative electrode conductive agent can be reduced.
  • the mass proportion of the additive is less than or equal to 10%. In some embodiments, based on the total mass of the negative electrode film layer, the mass proportion of the additive is 0.5%-5%.
  • the mass proportion of the additive is 50nm-500nm, and in some embodiments, the particle size Dv50 of the above additive is 100nm-200nm. By controlling the particle size within the above range, a larger specific surface area can be obtained and the reaction activity can be increased.
  • the negative electrode film layer includes a negative electrode active material, and the negative electrode active material includes a carbon material, and the carbon material can be at least one of graphite (including artificial graphite, natural graphite), soft carbon, and hard carbon. In some embodiments, the carbon material is graphite.
  • the negative electrode active material also includes a silicon-based material. In some embodiments, the mass proportion of the silicon-based material in the negative electrode active material is greater than or equal to 5%. In some embodiments, the mass proportion of the silicon-based material in the negative electrode active material is 5%-25%. In some embodiments, the mass proportion of the silicon-based material in the negative electrode active material is 5%-20%.
  • the silicon-based material for example, at least one of silicon element, silicon-carbon composite material, and silicon-oxygen compound is included.
  • the silicon-oxygen compound has higher capacity performance and cycle life.
  • the energy density of the secondary battery can be greatly improved.
  • the silicon-based negative electrode material undergoes a huge volume change during the embedding and de-embedding process of active ions, such as lithium ions.
  • the electrode material is likely to generate internal stress due to the volume effect, causing the surface SEI to rupture. Frequent repair of SEI consumption is It consumes a lot of active lithium; in addition, it is easy to cause the electrode material to break, thereby losing electrical contact with the current collector, which leads to poor storage performance of the silicon-based negative electrode.
  • the negative electrode film layer of the secondary battery of the present application contains the above additive.
  • the additive can form a highly elastic polymer with the cyclic carbonate compound in the electrolyte to participate in SEI film formation, thereby effectively alleviating the volume expansion of the silicon-based material during charging at the negative electrode-electrolyte interface, and improving the battery capacity and the stability of the interface between the negative electrode and the electrolyte. It can be seen that through this embodiment, the secondary battery of the present application has high storage performance and high energy density.
  • the above-mentioned negative electrode film layer is configured as a double-layer structure, that is, including a first negative electrode film layer and a second negative electrode film layer, the above-mentioned second negative electrode film layer is arranged between the above-mentioned negative electrode current collector and the above-mentioned first negative electrode film layer, and the above-mentioned first negative electrode film layer and/or the above-mentioned second negative electrode film layer include the above-mentioned additive.
  • the mass proportion of the above-mentioned additive in the above-mentioned first negative electrode film layer is greater than 0% and less than or equal to 10%. In some embodiments, the mass proportion of the above-mentioned additive in the above-mentioned first negative electrode film layer is 0.5%-5%; and/or, the mass proportion of the above-mentioned additive in the above-mentioned second negative electrode film layer is 0%-5%. In some embodiments, the mass proportion of the above-mentioned additive in the above-mentioned second negative electrode film layer is 0.1%-2%. When both the first negative electrode film layer and the second negative electrode film layer include additives, the additives in the two layers may be the same or different. When the mass proportion of the additive in the first negative electrode film layer is recorded as A1 and the mass proportion of the additive in the second negative electrode film layer is recorded as A2, A1/A2>1; in some embodiments, 2 ⁇ A1/A2 ⁇ 10.
  • the first negative electrode film layer includes a first negative electrode active material
  • the second negative electrode film layer includes a second negative electrode active material
  • the first negative electrode active material and/or the second negative electrode active material include the silicon-based material.
  • both the first negative electrode active material and the second negative electrode active material include the silicon-based material
  • the mass proportion of the silicon-based material in the first negative electrode active material is greater than the mass proportion of the silicon-based material in the second negative electrode active material.
  • the mass proportion of the silicon-based material in the first negative electrode active material is greater than or equal to 5%. In some embodiments, the mass proportion of the silicon-based material in the first negative electrode active material is 5%-25%.
  • the mass proportion of the silicon-based material in the first negative electrode active material is 5%-20%.
  • the type of the silicon-based material is the same as described above.
  • the first negative electrode active material further comprises a carbon material, the carbon material comprising at least one of graphite, soft carbon, and hard carbon.
  • the carbon material comprises graphite.
  • the second negative electrode active material comprises a carbon material, which is the same as or different from the carbon material in the negative electrode film layer.
  • the carbon material comprises a high-density graphite material with a powder pressure of 1.8 g/cm3 or more .
  • the negative electrode sheet comprising the first and second negative electrode film layers may be prepared, for example, as follows.
  • a slurry containing high-compacted graphite and/or additives with a powder pressure of 1.8 g/cm 3 or more is coated on both sides of the current collector 1 to form a second negative electrode film layer 22, and then a composite slurry containing graphite, silicon-based materials, additives, etc. is coated on this basis to form a first negative electrode film layer 21, forming a double-layer negative electrode film layer 2, thereby obtaining a negative electrode sheet, as shown in Figure 1.
  • the negative electrode film layer includes both high-valent sulfur and low-valent sulfur, and/or, the negative electrode film layer includes both high-valent selenium and low-valent selenium.
  • the high-valent sulfur includes at least one of +4-valent sulfur and +6-valent sulfur, and the S2p spectrum peak is 168.5eV-171eV; the low-valent sulfur includes -2-valent sulfur to -1/6-valent sulfur, and the S2p spectrum peak is 161eV-166.5eV.
  • the high-valent selenium includes at least one of +4-valent selenium and +6-valent selenium, and the Se3d spectrum peak of the high-valent selenium is 58.9eV-61.2eV; in some embodiments, the low-valent selenium includes -2-valent selenium, and the Se3d spectrum peak of the low-valent selenium is 54eV-55.1eV.
  • the generation of the above-mentioned high-valent sulfur and high-valent selenium is due to the oxidation after losing electrons to generate alkyl sulfates and alkyl selenates that participate in SEI film formation, and the generation of low-valent sulfur and low-valent selenium is due to the reduction after gaining electrons to generate PEO polymers that participate in SEI film formation.
  • the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • a metal foil a copper foil may be used.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by mixing a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloys, etc.) are formed on a polymer material substrate (such as a substrate made of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer may further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared in the following manner: the above-mentioned components for preparing the negative electrode sheet, such as the negative electrode active material (carbon material and/or silicon-based material), the above-mentioned additives, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet is obtained.
  • a solvent such as deionized water
  • the secondary battery of the present application includes a positive electrode sheet.
  • the positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, and the positive electrode film layer includes a lithium supplement, and the lithium supplement includes at least one of lithium sulfide, lithium selenide, lithium oxide, and lithium nitride. Since active lithium is consumed in the process of sulfur-containing substances/selenium-containing substances in the negative electrode plate forming lithium polysulfide/lithium polyselenide, by including a lithium supplement in the positive electrode film layer, active lithium can be supplemented, so that the secondary battery has high energy density and fast charging performance.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene terephthalate (PE), polystyrene (PS), polystyrene (PE ... It is formed on a substrate such as PE.
  • a metal material aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • a polymer material substrate such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene terephthalate (PET), polybuty
  • the positive electrode active material in the positive electrode film layer may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: a lithium-containing phosphate with an olivine structure, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 , LiMn 2 O 4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ) , and LiNi 0.8 Co 0.2 Mn 0.2 O 2 (also referred to as NCM 811 ,
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may also optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-tetrafluoroethylene-propylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode film layer may further include a conductive agent, for example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder, the lithium supplement and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • a solvent such as N-methylpyrrolidone
  • the electrolyte includes a cyclic carbonate compound.
  • the cyclic carbonate compound includes at least one of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, vinylene carbonate and butylene carbonate. These compounds can undergo nucleophilic reaction with the additive in the negative electrode film layer, participate in the formation of the SEI film, and improve the storage performance of the secondary battery.
  • the electrolyte includes an organic solvent and an electrolyte salt dispersed in the organic solvent.
  • the specific types and compositions of the organic solvent and the lithium salt are not subject to specific restrictions and can be selected according to actual needs.
  • the electrolyte salt can be selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate and lithium tetrafluorooxalate phosphate.
  • cyclic carbonate compounds in addition to the above-mentioned cyclic carbonate compounds, it can also be selected from ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the secondary battery of the present application also includes a separator.
  • the present application has no particular restrictions on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be the same or different, without particular limitation.
  • the secondary battery of the present application can be prepared by conventional methods, for example, the positive electrode sheet, the separator, and the negative electrode sheet are wound or stacked in sequence, so that the separator is between the positive electrode sheet and the negative electrode sheet to play an isolating role, and the battery cell is placed in an outer package, and the electrolyte is injected to obtain an electrode assembly.
  • the above-mentioned outer package can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the above-mentioned outer package can also be a soft package, such as a bag-type soft package.
  • the material of the soft package can be plastic, and as plastic, polypropylene, polybutylene terephthalate, and polybutylene succinate can be listed.
  • the present application has no particular limitation on the shape of the secondary battery, which may be cylindrical, square, or any other shape.
  • secondary batteries may be assembled into a battery module.
  • the number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.
  • the negative electrode slurry is coated on the two surfaces of the negative electrode current collector copper foil, and after drying and cold pressing, a negative electrode sheet is obtained.
  • LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), conductive agent Super P, and binder polyvinylidene fluoride were mixed in a weight ratio of 96%:2%:2%, and an appropriate amount of solvent NMP was added and stirred evenly to obtain a positive electrode slurry.
  • the positive electrode slurry was coated on both surfaces of the positive electrode current collector aluminum foil, and after drying and cold pressing, a positive electrode sheet was obtained.
  • LiPF6 lithium salt was added thereto to dissolve, and stirred evenly.
  • the final concentration of LiPF6 lithium salt was 12.5%, which was used as an electrolyte.
  • a polyethylene film is used as the isolation film.
  • the positive electrode sheet, separator, and negative electrode sheet are stacked in order, the separator is placed between the positive and negative electrode sheets, and wound to obtain a battery cell.
  • the battery cell is placed in a battery outer package, and then injected with electrolyte, packaged, left to stand, formed, shaped, and tested for capacity to prepare a lithium-ion battery having a thickness of 4.2 mm, a width of 42 mm, and a length of 49.5 mm.
  • the preparation method is similar to that of Example 1, except that different types or contents of additives are used, as shown in Table 1 for details.
  • the preparation method is similar to that of Example 1, except that the preparation method of the negative electrode sheet is as follows:
  • the second negative electrode active material artificial graphite and silicon oxide, the mass ratio of the two is 95%:5%
  • conductive agent Super P carbon nanotubes
  • CNTs carbon nanotubes
  • binder styrene butadiene rubber thickener sodium carboxymethyl cellulose
  • the first slurry and the second slurry are extruded simultaneously through a double-chamber coating device.
  • the second slurry is coated on both surfaces of the negative electrode current collector copper foil, and the first slurry is coated on the second slurry; after drying and cold pressing, a negative electrode sheet is obtained.
  • the preparation method is similar to that of Example 1, except that: the preparation method of the negative electrode plate is as follows: the negative electrode active material (artificial graphite and silicon oxide, the mass ratio of the two is 90%:10%), the conductive agent Super P, carbon nanotubes (CNTs), the binder styrene butadiene rubber, and the thickener sodium carboxymethyl cellulose are fully stirred and mixed in an appropriate amount of solvent deionized water in a weight ratio of 96.5%:1%:0.5%:1%:1% to form a negative electrode slurry.
  • the negative electrode active material artificial graphite and silicon oxide, the mass ratio of the two is 90%:10%)
  • the conductive agent Super P carbon nanotubes (CNTs)
  • CNTs carbon nanotubes
  • binder styrene butadiene rubber the binder styrene butadiene rubber
  • thickener sodium carboxymethyl cellulose are fully stirred and mixed in an appropriate amount of solvent deionized water in a weight
  • the negative electrode slurry is coated on the two surfaces of the negative electrode current collector copper foil, and after drying and cold pressing, a negative electrode sheet is obtained.
  • the preparation method is similar to that of Example 15, except that the preparation method of the negative electrode sheet is as follows:
  • the first active material artificial graphite and silicon oxide, with a mass ratio of 80%:20%), conductive agent Super P, carbon nanotubes (CNTs), binder styrene-butadiene rubber, and thickener sodium carboxymethyl cellulose are fully stirred and mixed in an appropriate amount of solvent deionized water in a weight ratio of 96.5%:1%:0.5%:1%:1% to form a first slurry.
  • the second active material artificial graphite and silicon oxide, with a mass ratio of 95%:5%
  • conductive agent Super P carbon nanotubes
  • CNTs carbon nanotubes
  • binder styrene-butadiene rubber binder styrene-butadiene rubber
  • thickener sodium carboxymethyl cellulose were fully stirred and mixed in a proper amount of solvent deionized water in a weight ratio of 96.5%:1%:0.5%:1%:1% to form a second slurry.
  • the first slurry and the second slurry are extruded simultaneously through a double-chamber coating device.
  • the second slurry is coated on both surfaces of the negative electrode current collector copper foil, and the first slurry is coated on the second slurry; After drying and cold pressing, the negative electrode sheet is obtained.
  • the rolled film was cut into a rectangular size of about 5 cm ⁇ 10 cm and placed between the two electrodes of the film resistance meter.
  • the test pressure was set to 25 MPa and the holding time was set to 25 s on the MRMS software.
  • the software automatically read the film thickness, resistance, resistivity, conductivity and other data and recorded the resistance data.
  • the test process of 10%-80% SOC charging time is as follows: at 25°C, the batteries in the embodiment and comparative example are charged from 10% SOC to 80% SOC at 1.0C/0.8C/0.5C/0.33C step by step.
  • the charging time when no lithium deposition occurs at the negative electrode is the fast charging time of the battery at this time. The shorter the fast charging time, the better the fast charging performance of the battery.
  • the additives in Examples 5 to 7 are in the form of a composite with carbon nanotubes or have a carbon coating layer, which not only has excellent storage performance of the battery, but also reduces resistance and improves the conductivity of the secondary battery, thereby obtaining better Fast charging performance.
  • Examples 8 to 14 compared with Example 14, Examples 8 to 13 obtain excellent storage performance, conductivity and fast charging performance by making the mass proportion of the additive less than or equal to 10% relative to the total mass of the negative electrode film layer. Furthermore, compared with Examples 12 and 13, Examples 8 to 11 obtain even better storage performance, conductivity and fast charging performance by making the mass proportion of the additive 0.5%-5% relative to the total mass of the negative electrode film layer.
  • Example 15 by making the negative electrode film layer a double-layer structure, the storage performance and fast charging performance of the secondary battery can be further improved.
  • Comparative Examples 1 and 2 do not contain the specific additives of the present application, the storage performance is not improved and the technical effect of the present application cannot be obtained.

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Abstract

一种二次电池以及包括该二次电池的用电装置。所述二次电池包括负极极片，所述负极极片包括负极集流体和设置在所述负极集流体的至少一个表面上的负极膜层，所述负极膜层包括能够与环状碳酸酯类化合物进行亲核反应的添加剂。所述的二次电池具有高存储性能。

Description

二次电池以及包括该二次电池的用电装置
交叉引用
本申请引用于2023年6月7日递交的名称为“二次电池以及包括该二次电池的用电装置”的第202310675468.X号中国专利申请，其通过引用被全部并入本申请。
技术领域
本申请涉及电池技术领域，尤其涉及一种二次电池以及包括该二次电池的用电装置。
背景技术
近年来，二次电池被广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。由于二次电池取得了极大的发展，因此对其性能也提出了更高的要求。
因此，如何使二次电池具有更好的存储性能，成为本领域亟待解决的问题。
发明内容
本申请是鉴于上述课题而进行的，其目的在于，提供一种二次电池以及包括该二次电池的用电装置，该二次电池具有高存储性能。
为了达到上述目的，本申请的第一方面提供了一种二次电池，包括负极极片，负极极片包括负极集流体和设置在负极集流体的至少一个表面上的负极膜层，负极膜层包括能够与环状碳酸酯类化合物进行亲核反应的添加剂。
由此，本申请的二次电池通过使负极膜层包括能够与环状碳酸酯类化合物进行亲核反应的添加剂，提高了二次电池的存储性能。
在任意实施方式中，添加剂包括含硫物质、含硒物质、含硫物质与碳基材料的复合物、含硒物质与碳基材料的复合物、具有碳包覆层的含硫物质、具有碳包覆层的含硒物质中的至少一种；可选地，含硫物质包括单质硫、硫化锂、硫化钠中的至少一种；可选地，含硒物质包括硒单质、硒化锂、硒化钠、硒化钴、硒化镍中的至少一种；可选地，碳基材料包括纳米碳基材料、石墨烯，可选地，纳米碳基材料包括碳纳米管。该含硫物质和含硒物质在电池充放电中发生还原反应，与环状碳酸酯类化合物进行亲核反应，参与形成SEI膜，另外，通过与碳纳米管复合、或具有碳包覆层，能够提高电池的导电性和快充性能。
在任意实施方式中，基于负极膜层的总质量，添加剂的质量占比小于等于10％，可选为0.5％-5％。由此，能够在获得高存储性能的同时，使得电池获得优异的导电性和快充性能。
在任意实施方式中，添加剂的粒径Dv50为50nm-500nm，可选为100nm-200nm。通过将粒径控制在上述范围内，能够获得更大的比表面积，增加反应活性。
在任意实施方式中，负极膜层包括负极活性材料，负极活性材料包括硅基材料；可选地，硅基材料在负极活性材料中的质量占比大于等于5％，更可选为5％-25％；可选地，硅基材料包括硅单质、硅碳复合材料、硅氧化合物中的至少一种。通过在负极膜层中加入硅基材料能够提升电池的能量密度。
在任意实施方式中，负极膜层包括第一负极膜层和第二负极膜层，第二负极膜层设置在负极集流体和第一负极膜层之间，第一负极膜层和/或第二负极膜层包括添加剂。
在任意实施方式中，在第一负极膜层中，添加剂的质量占比大于0％且小于等于10％，可选为0.5％-5％，在第二负极膜层中，添加剂的质量占比为0％-5％，可选为0.1％-2％。
在任意实施方式中，第一负极膜层和第二负极膜层均包括添加剂，且第一负极膜层和第二负极膜层中的添加剂材质相同或不同。
在任意实施方式中，第一负极膜层和第二负极膜层均包括添加剂； 在第一负极膜层中，添加剂的质量占比记为A1，在第二负极膜层中，添加剂的质量占比记为A2；二次电池满足：A1/A2＞1；可选地，2≤A1/A2≤10。
在任意实施方式中，第一负极膜层包括第一负极活性材料，第二负极膜层包括第二负极活性材料，第一负极活性材料和/或第二负极活性材料包括硅基材料；可选地，第一负极活性材料和第二负极活性材料均包括硅基材料，且第一负极活性材料中硅基材料的质量占比大于第二负极活性材料中硅基材料的质量占比。
在任意实施方式中，硅基材料在第一负极活性材料中的质量占比大于等于5％，可选为5％-25％。
在任意实施方式中，第一负极活性材料和/或第二负极活性材料还包括碳材料；可选地，碳材料包括石墨，更可选为粉压在1.8g/cm3以上的高压实石墨。
本申请通过上述双层负极膜层的设置方式，使得二次电池获得更加优异的存储性能和导电性。
在任意实施方式中，二次电池包括正极极片，正极极片包括正极集流体和设置在正极集流体的至少一个表面上的正极膜层，正极膜层包括补锂剂；可选地，补锂剂包括硫化锂、硒化锂、氧化锂、氮化锂中的至少一种。通过在正极膜层中包括补锂剂，能够补充活性锂，使得二次电池具有高能量密度和快充性能。
在任意实施方式中，二次电池包括电解液，电解液包括环状碳酸酯类化合物；可选地，环状碳酸酯类化合物包括碳酸乙烯酯、氟代碳酸乙烯酯、双氟代碳酸乙烯酯、碳酸亚乙烯酯以及碳酸丁烯酯中的至少一种。由此，与负极膜层中的添加剂进行亲核反应，参与形成SEI膜，提高二次电池存储性能。
在任意实施方式中，在负极膜层同时包括高价态硫和低价态硫，和/或，在负极膜层同时包括高价态硒和低价态硒；可选地，高价态硫包括+4价硫，+6价硫中的至少一种；可选地，高价态硫的S2p谱峰为168.5eV-171eV；可选地，低价态硫包括-2价硫至-1/6价硫，可选地，低价态硫的S2p谱峰为161eV-166.5eV。可选地，高价态硒包括 +4价硒，+6价硒中的至少一种；可选地，高价态硒的Se3d谱峰为58.9eV-61.2eV；可选地，低价态硒包括-2价硒；可选地，低价态硒的Se3d谱峰为54eV-55.1eV。
本申请的第二方面提供一种用电装置，其包括本申请第一方面的二次电池。
发明的效果
根据本申请，能够提供存储性能优异的二次电池及包含该锂离子电池的用电装置。
附图说明
图1为本申请的二次电池中的负极极片的概略构成图。
附图标记说明：
1负极集流体；2负极膜层；21第一负极膜层；22第二负极膜
层
具体实施方式
以下，适当地参照附图详细说明本申请的二次电池、以及包括该二次电池的用电装置。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
二次电池是指在电池放电后可通过充电的方式使活性材料激活而继续使用的电池，例如，锂离子电池等。通常情况下，二次电池包括正极极片、负极极片、隔离膜及电解液。在电池充放电过程中，活性离子(例如锂离子)在正极极片和负极极片之间往返嵌入和脱出。电解液在正极极片和负极极片之间，主要起到传导活性离子的作用。
本申请的一个实施方式提供一种二次电池，包括负极极片，该负极极片包括负极集流体和设置在所述负极集流体的至少一个表面上的负极膜层，该负极膜层包括能够与环状碳酸酯类化合物进行亲核反应的添加剂。
本申请人意外地发现：在负极膜层中添加能够与环状碳酸酯类化合物进行亲核反应的添加剂时，该添加剂与二次电池的电解液中的环状碳酸酯类化合物进行反应，诱导其开环，形成高弹性的类PEO聚合物，参与SEI形成强化成膜，减少因SEI破裂频繁修复消耗活性锂带来的不可逆容量损失；同时形成高离子电导率的导电网络，有利于二次电池中活性离子(例如锂离子等)的迁移，降低电荷转移阻抗和电化学极化，减少极化容量损失，从而提高电池的存储性能。
对于添加剂，只要能够与环状碳酸酯类化合物进行亲核反应即可，没有特别的限定。在一些实施方式中，作为该添加剂，包括含硫物质和/或含硒物质，例如，包括单质硫、硫化锂、硫化钠、含硒单质、硒化锂、硒化钠、硒化钴、硒化镍中的至少一种。这些添加剂在电池的充放电过程中发生还原反应，进一步与环状碳酸酯类电解液溶剂反应。例如，硫化锂与碳酸乙烯酯反应，生成聚(环氧乙烷)(PEO)-类聚合物，参与形成SEI膜。具体反应如下所示。
另外，在一些实施方式中，以碳基材料为基底，将含硫物质和/或含硒物质负载在碳基材料上形成复合物，该碳基材料包括纳米碳基材料、石墨烯等，在一些实施方式中，该纳米碳基材料为碳纳米管。另外，也可以用碳作为包覆材料，在一些实施方式中用纳米多孔碳作为包覆材料，对上述含硫物质和/或含硒物质的表面进行包覆，形成具有碳包覆层的含硫物质、具有碳包覆层的含硒物质。由此能够在提高电池存储性能的同时，提高电池的导电性和快充性能，此外，还能降低负极导电剂的用量。
在一些实施方式中，基于负极膜层的总质量，该添加剂的质量占比小于等于10％。在一些实施方式中，基于负极膜层的总质量，该添加剂的质量占比为0.5％-5％。通过使添加剂的含量在上述范围内，能够进一步提高电池的存储性能、导电性和快充性能。在一些实施方式中，上述添加剂的粒径Dv50为50nm-500nm，在一些实施方式中，上述添加剂的粒径Dv50为100nm-200nm。通过将粒径控制在上述范围内，能够获得更大的比表面积，增加反应活性。
在一些实施方式中，该负极膜层包括负极活性材料，该负极活性材料包括碳材料，该碳材料可以为石墨(包括人造石墨、天然石墨)、软碳、硬碳中的至少一种。在一些实施方式中，该碳材料为石墨。该负极活性材料还包括硅基材料，在一些实施方式中，该硅基材料在该负极活性材料中的质量占比大于等于5％，在一些实施方式中，该硅基材料在该负极活性材料中的质量占比为5％-25％，在一些实施方式中，该硅基材料在该负极活性材料中的质量占比为5％-20％。作为该硅基材料，例如，包括硅单质、硅碳复合材料、硅氧化合物中的至少一种，在一些实施方式中，该硅基材料包括硅氧化合物，化学式为SiOx，其中0＜x＜2，在一些实施方式中，0.5≤x≤1.5，在一些实施方式中，x＝1。该硅氧化合物具有较高的容量性能和循环寿命。
在负极膜层中通过包含硅基材料作为负极活性材料，能够大大地提升了二次电池的能量密度。但另一方面，硅基负极材料在活性离子、例如锂离子的嵌入与脱嵌过程中存在巨大的体积变化，电极材料很有可能因体积效应产生内部应力而造成表面SEI破裂，频繁修复SEI消 耗大量活性锂；此外还易造成电极材料破碎，从而丧失与集流体的电接触，以上导致硅基负极存储性能差，但本申请的二次电池的负极膜层中含有上述添加剂，如上所述，该添加剂能够与电解液中的环状碳酸酯类化合物形成高弹性的聚合物参与SEI成膜，由此可在负极-电解液界面有效地缓解充电过程中硅基材料的体积膨胀，提高电池容量及负极与电解液界面稳定性。由此可见，通过该实施方式，本申请的二次电池在具有高存储性能的同时，兼具高能量密度。
在本申请中，在一些实施方式中，上述负极膜层设置为双层结构，即，包括第一负极膜层和第二负极膜层，上述第二负极膜层设置在上述负极集流体和上述第一负极膜层之间，上述第一负极膜层和/或上述第二负极膜层包括上述添加剂。
在一些实施方式中，上述添加剂在上述第一负极膜层中的质量占比大于0％且小于等于10％，在一些实施方式中，上述添加剂在上述第一负极膜层中的质量占比为0.5％-5％；和/或，上述添加剂在上述第二负极膜层中的质量占比为0％-5％，在一些实施方式中，上述添加剂在上述第二负极膜层中的质量占比为0.1％-2％。第一负极膜层和第二负极膜层均包括添加剂时，两层中的添加剂可以相同也可以不同。将第一负极膜层中添加剂的质量占比记为A1、将第二负极膜层中添加剂的质量占比记为A2时，A1/A2＞1；在一些实施方式中，2≤A1/A2≤10。
在一些实施方式中，上述第一负极膜层包括第一负极活性材料，上述第二负极膜层包括第二负极活性材料，上述第一负极活性材料和/或上述第二负极活性材料包括上述硅基材料。在一些实施方式中，上述第一负极活性材料和上述第二负极活性材料均包括上述硅基材料，且上述第一负极活性材料中上述硅基材料的质量占比大于上述第二负极活性材料中上述硅基材料的质量占比。该硅基材料在该第一负极活性材料中的质量占比大于等于5％，在一些实施方式中，该硅基材料在该第一负极活性材料中的质量占比为5％-25％，在一些实施方式中，该硅基材料在该第一负极活性材料中的质量占比为5％-20％。该硅基材料的种类与上述相同。除硅基材料之外，该第一负极活性材料 还包括碳材料，碳材料包括石墨、软碳、硬碳中的至少一种。在一些实施方式中，碳材料包括石墨。另外，上述第二负极活性材料包括碳材料，该碳材料与负极膜层中的碳材料相同或不同，在一些实施方式中，该碳材料包括粉压为1.8g/cm3以上的高压实石墨材料。
对于上述包含第一和第二负极膜层的负极极片，例如可以如下制备。
通过双层涂布技术，首先在集流体1的两面涂布包含粉压为1.8g/cm3以上的高压实石墨和/或添加剂的浆料形成第二负极膜层22，再在此基础上涂布包含石墨、硅基材料、添加剂等的复合浆料形成第一负极膜层21，形成双层负极膜层2，由此得到负极极片，如图1所示。通过这种复合浆料和双层涂布的方式，充分发挥了石墨和硅基材料的优点，通过垂直集流体方向上的不同分布，能够改善负极极片的快充性能，获得高快充性能、高压实的负极极片。
在一些实施方式中，在上述负极膜层同时包括高价态硫和低价态硫，和/或，在上述负极膜层同时包括高价态硒和低价态硒。在一些实施方式中，上述高价态硫包括+4价硫，+6价硫中的至少一种，S2p谱峰为168.5eV-171eV；上述低价态硫包括-2价硫至-1/6价硫，S2p谱峰为161eV-166.5eV。在一些实施方式中，上述高价态硒包括+4价硒，+6价硒中的至少一种、高价态硒的Se3d谱峰为58.9eV-61.2eV；在一些实施方式中，上述低价态硒包括-2价硒，上述低价态硒的Se3d谱峰为54eV-55.1eV。上述高价态硫、高价态硒的产生是由于失电子后氧化生成烷基硫酸盐、烷基硒酸盐参与SEI成膜，低价态硫、低价态硒的产生是由于得电子后还原生成PEO类聚物参与SEI成膜。
在本申请的二次电池中，作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。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(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)上而形成。
在一些实施方式中，负极膜层还可选地包括粘结剂。作为示例，粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施方式中，负极膜层还可选地包括导电剂。作为示例，导电剂可选自超导碳、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。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料(碳材料和/或硅基材料)、上述添加剂、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，在得到负极极片。
在本申请的二次电池中包括正极极片。
在一些实施方式中，上述正极极片包括正极集流体和设置在上述正极集流体的至少一个表面上的正极膜层，上述正极膜层中包括补锂剂，该补锂剂包括硫化锂、硒化锂、氧化锂、氮化锂中的至少一种。由于在负极极片中含硫物质/含硒物质形成多硫化锂/多硒化锂的过程中消耗活性锂，因此，通过在正极膜层中包括补锂剂，能够补充活性锂，使得二次电池具有高能量密度和快充性能。
在一些实施方式中，正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。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层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(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)上而形成。
在一些实施方式中，正极膜层中的正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO2)、锂镍氧化物(如LiNiO2)、锂锰氧化物(如LiMnO2、LiMn2O4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi1/3Co1/3Mn1/3O2(也可以简称为NCM333)、LiNi0.5Co0.2Mn0.3O2(也可以简称为NCM523)、LiNi0.5Co0.25Mn0.25O2(也可以简称为NCM211)、LiNi0.6Co0.2Mn0.2O2(也可以简称为NCM622)、LiNi0.8Co0.1Mn0.1O2(也可以简称为NCM811)、锂镍钴铝氧化物(如LiNi0.85Co0.15Al0.05O2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，导电剂可以包括超导碳、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。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂、补锂剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。
本申请的二次电池中，电解液包括环状碳酸酯类化合物，在一些实施方式中，上述环状碳酸酯类化合物包括碳酸乙烯酯、氟代碳酸乙烯酯、双氟代碳酸乙烯酯、碳酸亚乙烯酯以及碳酸丁烯酯中的至少一种。这些化合物能够与负极膜层中的添加剂进行亲核反应，参与形成SEI膜，提高二次电池存储性能。
在一些实施方式中，电解液中包括有机溶剂、分散于有机溶剂中的电解质盐，有机溶剂和锂盐的具体种类及组成均不受到具体的限制，可根据实际需求进行选择。例如，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。对于溶剂，除了上述环状碳酸酯类化合物之外，还可选自碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
本申请的二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
本申请的二次电池可以采用常规方法进行制备，例如，将正极极片、隔离膜、负极极片按顺序卷绕或叠片，使隔离膜处于正极极片与负极极片之间起到隔离的作用，得到电芯，将电芯置于外包装中，注入电解液，得到电极组件。上述外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。上述外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
另外，本申请还提供一种用电装置，该用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。该二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。该用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为上述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
实施例
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例1
(1)负极极片的制备
将负极活性材料(人造石墨和氧化亚硅，二者质量比为90％：10％)、添加剂单质硫(粒径Dv50＝200nm)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比94.5％：2％：1％：0.5％：1％：1％在适量的溶剂去离子水中充分搅拌 混合，形成负极浆料。
将负极浆料涂布在负极集流体铜箔的两个表面上，经干燥、冷压后，得到负极极片。
(2)正极极片的制备
将LiNi0.8Co0.1Mn0.1O2(NCM811)、导电剂Super P、粘结剂聚偏氟乙烯按照重量比96％:2％:2％混合，加入适量溶剂NMP，搅拌均匀，获得正极浆料。将正极浆料涂布在正极集流体铝箔的两个表面上，经干燥、冷压后，获得正极极片。
(3)电解液
在氩气气氛手套箱中(H2O<0.01ppm，O2<0.01ppm)，将溶剂碳酸乙烯酯(EC)和碳酸甲乙酯(EMC)按照体积比4：6混合均匀，向其中加入LiPF6锂盐使其溶解，搅拌均匀，最终LiPF6锂盐的浓度为12.5％，作为电解液。
(4)隔离膜
采用聚乙烯膜作为隔离膜。
(5)锂离子电池
将上述正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正负极极片中间，卷绕得到电芯。将电芯置于电池外包装中，之后注入电解液、封装、静置、化成、整形、容量测试，制备得到锂离子电池，该锂离子电池的厚度为4.2mm，宽度为42mm，长度为49.5mm。
实施例2-14
与实施例1的制备方法相似，不同点在于：采用了不同种类或不同含量的添加剂，具体详见表1。
实施例15
与实施例1的制备方法相似，不同点在于：负极极片的制备方法如下：
将第一负极活性材料(人造石墨和氧化亚硅，二者质量比为80％：20％)、单质硫与碳纳米管的复合材料(粒径Dv50＝200nm)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比94.5％：2％：1％：0.5％：1％：1％在适量的溶剂去离子水 中充分搅拌混合，形成第一浆料。
将第二负极活性材料(人造石墨和氧化亚硅，二者质量比为95％：5％)、纳米多孔碳包覆的单质硒(粒径Dv50＝200nm)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比96％：0.5％：1％：0.5％：1％：1％在适量的溶剂去离子水中充分搅拌混合，形成第二浆料。
通过双腔涂布设备，将第一浆料和第二浆料同时挤出。第二浆料涂布在负极集流体铜箔的两个表面上，第一浆料涂布在第二浆料上；经干燥、冷压后，得到负极极片。
比较例1
与实施例1的制备方法相似，不同点在于：负极极片的制备方法如下：将负极活性材料(人造石墨和氧化亚硅，二者质量比为90％：10％)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比96.5％：1％：0.5％：1％：1％在适量的溶剂去离子水中充分搅拌混合，形成负极浆料。
将负极浆料涂布在负极集流体铜箔的两个表面上，经干燥、冷压后，得到负极极片。
比较例2
与实施例15的制备方法相似，不同点在于：负极极片的制备方法如下：
将第一活性材料(人造石墨和氧化亚硅，二者质量比为80％：20％)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比96.5％：1％：0.5％：1％：1％在适量的溶剂去离子水中充分搅拌混合，形成第一浆料。
将第二活性材料(人造石墨和氧化亚硅，二者质量比为95％：5％)、导电剂Super P、碳纳米管(CNTs)、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠按照重量比96.5％：1％：0.5％：1％：1％在适量的溶剂去离子水中充分搅拌混合，形成第二浆料。
通过双腔涂布设备，将第一浆料和第二浆料同时挤出。第二浆料涂布在负极集流体铜箔的两个表面上，第一浆料涂布在第二浆料上； 经干燥、冷压后，得到负极极片。
针对上述各实施例和比较例的二次电池进行如下测试，其结果一并示于下述表1。
电池测试
存储性能(60℃存储100天后的容量保持率)
电池容量恢复率测试过程如下：存储前，在25℃下，将实施例和比较例的电池，以1/3C恒电流充电至4.25V，再以4.25V恒压充电至0.05C，搁置30min，再以1/3C放电至2.8V，所得容量记为初始容量C0。在60℃下存储100天后，电池温度冷却至室温，重复以上步骤，测得容量记为Cr，则存储100天后的电池容量恢复率H＝Cr/C0*100％。
H越高存储性能越好。
导电性(极片膜片电阻)
将辊压后的膜片剪切成约5cm×10cm的长方形尺寸，放置于膜片电阻仪两电极之间，在MRMS软件上设置测试压强25Mpa，保压时间25s，软件自动读取膜片厚度、电阻、电阻率、电导率等数据，记录电阻数据。
电阻值越小表示导电性越好
快充性能(10％-80％SOC快充时间)
10％-80％SOC充电时间测试流程如下：在25℃下，将实施例和比较例中的电池从10％SOC以1.0C/0.8C/0.5C/0.33C分步充电至80％SOC，负极不发生析锂的充电时间为此时电池的快充时间。快充时间越短表示电池的快充性能越好。
表1
根据上述表1的结果可知，与比较例1、2相比，实施例1～15的二次电池均获得了优异的存储性能。
并且，与实施例1～4相比，实施例5～7中添加剂通过采用与碳纳米管的复合物的形式或者具有碳包覆层，不仅电池的存储性能优异，而且还降低电阻，提高了二次电池的导电性，获得了更好 的快充性能。
在实施例8～14中，与实施例14相比，实施例8～13通过相对于负极膜层的总质量使添加剂的质量占比小于等于10％，获得了优异的存储性能、导电性以及快充性能，进而，与实施例12、13相比，实施例8～11通过相对于负极膜层的总质量使添加剂的质量占比为0.5％-5％，获得了更加优异的存储性能、导电性以及快充性能。
此外，实施例15中通过使负极膜层为双层结构，能够使得二次电池的存储性能和快充性能进一步提高。
而相对于此，比较例1、2中由于并未含有本申请中的特定的添加剂，存储性能未能提高，不能获得本申请的技术效果。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (15)

  1. 一种二次电池，包括负极极片，所述负极极片包括负极集流体和设置在所述负极集流体的至少一个表面上的负极膜层，所述负极膜层包括能够与环状碳酸酯类化合物进行亲核反应的添加剂。
  2. 根据权利要求1所述的二次电池，其中，
    所述添加剂包括含硫物质、含硒物质、含硫物质与碳基材料的复合物、含硒物质与碳基材料的复合物、具有碳包覆层的含硫物质、或具有碳包覆层的含硒物质中的至少一种；
    可选地，所述含硫物质包括单质硫、硫化锂、或硫化钠中的至少一种；
    可选地，所述含硒物质包括硒单质、硒化锂、硒化钠、硒化钴、或硒化镍中的至少一种；
    可选地，所述碳基材料包括纳米碳基材料和/或石墨烯，可选地，所述纳米碳基材料包括碳纳米管。
  3. 根据权利要求1或2所述的二次电池，其中，
    基于所述负极膜层的总质量，所述添加剂的质量占比小于等于10％，可选为0.5％-5％。
  4. 根据权利要求1-3中任一项所述的二次电池，其中，
    所述添加剂的粒径Dv50为50nm-500nm，可选为100nm-200nm。
  5. 根据权利要求1-4中任一项所述的二次电池，其中，
    所述负极膜层包括负极活性材料，所述负极活性材料包括硅基材料，
    可选地，所述硅基材料在所述负极活性材料中的质量占比大于等于5％，可选地为大于等于10％；
    可选地，所述硅基材料包括硅单质、硅碳复合材料、硅氧化合物中的至少一种。
  6. 根据权利要求1-5中任一项所述的二次电池，其中，
    所述负极膜层包括第一负极膜层和第二负极膜层，所述第二负极 膜层设置在所述负极集流体和所述第一负极膜层之间，
    所述第一负极膜层和/或所述第二负极膜层包括所述添加剂。
  7. 根据权利要求6所述的二次电池，其中，
    在所述第一负极膜层中，所述添加剂的质量占比为大于0％且小于等于10％，可选为0.5％-5％，
    在所述第二负极膜层中，所述添加剂的质量占比为0％-5％，可选为0.1％-2％。
  8. 根据权利要求6或7所述的二次电池，其中，
    所述第一负极膜层和所述第二负极膜层均包括所述添加剂；
    在所述第一负极膜层中，所述添加剂的质量占比记为A1，在所述第二负极膜层中，所述添加剂的质量占比记为A2；所述二次电池满足：A1/A2＞1；可选地，2≤A1/A2≤10。
  9. 根据权利要求6～8中任一项所述的二次电池，其中，
    所述第一负极膜层和所述第二负极膜层均包括所述添加剂，且所述第一负极膜层和所述第二负极膜层中的添加剂材质相同或不同。
  10. 根据权利要求6～9中任一项所述的二次电池，其中，
    所述第一负极膜层包括第一负极活性材料，所述第二负极膜层包括第二负极活性材料，所述第一负极活性材料和/或所述第二负极活性材料包括所述硅基材料；
    可选地，所述第一负极活性材料和所述第二负极活性材料均包括所述硅基材料，且所述第一负极活性材料中所述硅基材料的质量占比大于所述第二负极活性材料中所述硅基材料的质量占比。
  11. 根据权利要求10所述的负极极片，其中，
    所述第一负极活性材料和/或所述第二负极活性材料还包括碳材料；可选地，所述碳材料包括石墨。
  12. 根据权利要求1-11中任一项所述的二次电池，其中，
    所述二次电池包括正极极片，所述正极极片包括正极集流体和设置在所述正极集流体的至少一个表面上的正极膜层，所述正极膜层包括补锂剂；
    可选地，所述补锂剂包括硫化锂、硒化锂、氧化锂、氮化锂中的 至少一种。
  13. 根据权利要求1-12中任一项所述的二次电池，其中，
    所述二次电池包括电解液，所述电解液包括环状碳酸酯类化合物；
    可选地，所述环状碳酸酯类化合物包括碳酸乙烯酯、氟代碳酸乙烯酯、双氟代碳酸乙烯酯、碳酸亚乙烯酯以及碳酸丁烯酯中的至少一种。
  14. 根据权利要求1-13中任一项所述的二次电池，其中，
    在所述负极膜层同时包括高价态硫和低价态硫，和/或，在所述负极膜层同时包括高价态硒和低价态硒；
    可选地，所述高价态硫包括+4价硫，+6价硫中的至少一种；
    可选地，所述高价态硫的S2p谱峰为168.5-171eV；
    可选地，所述低价态硫包括-2价硫至-1/6价硫；
    可选地，所述低价态硫的S2p谱峰为161-166.5eV；
    可选地，所述高价态硒包括+4价硒，+6价硒中的至少一种；
    可选地，所述高价态硒的Se3d谱峰为58.9-61.2eV；
    可选地，所述低价态硒包括-2价硒；
    可选地，所述低价态硒的Se3d谱峰为54-55.1eV。
  15. 一种用电装置，包括权利要求1-14中任一项所述的二次电池。
PCT/CN2024/070506 2023-06-07 2024-01-04 二次电池以及包括该二次电池的用电装置 Ceased WO2024250666A1 (zh)

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