WO2024087382A1 - Secondary battery and electric device - Google Patents

Secondary battery and electric device Download PDF

Info

Publication number
WO2024087382A1
WO2024087382A1 PCT/CN2022/143653 CN2022143653W WO2024087382A1 WO 2024087382 A1 WO2024087382 A1 WO 2024087382A1 CN 2022143653 W CN2022143653 W CN 2022143653W WO 2024087382 A1 WO2024087382 A1 WO 2024087382A1
Authority
WO
WIPO (PCT)
Prior art keywords
secondary battery
active material
positive electrode
electrode active
negative electrode
Prior art date
Application number
PCT/CN2022/143653
Other languages
French (fr)
Chinese (zh)
Inventor
张耀
王明旺
张旭辉
王宝玉
陈辉
Original Assignee
欣旺达动力科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 欣旺达动力科技股份有限公司 filed Critical 欣旺达动力科技股份有限公司
Publication of WO2024087382A1 publication Critical patent/WO2024087382A1/en

Links

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
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive 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 application relates to the field of battery technology, and in particular to a secondary battery and an electrical device.
  • Lithium-ion batteries have great advantages in the field of energy storage, but there are still some problems in practical applications. Taking lithium iron phosphate batteries as an example, the service life of lithium iron phosphate single cells is 4,000-6,000 times, which is difficult to meet the requirements of 20-30 years of service life (more than 10,000 cycles) for energy storage projects with high life requirements. Active lithium loss is the main factor in the life decay of energy storage lithium-ion batteries. During the battery cycle and lithium insertion and extraction process, due to the expansion and contraction of graphite, the dissolution of positive transition metals and other reasons, SEI ruptures and forms, the area and thickness of the SEI film increase, and the limited active lithium in the battery system is consumed, which ultimately shortens the battery life. How to reduce and supplement the consumption of active lithium during battery decay is a key issue in improving the life of lithium iron phosphate batteries.
  • the purpose of the present application is to provide a secondary battery, which improves the cycle and service life of the secondary battery by adjusting the relationship between the maximum reversible gram capacity of the positive electrode active material and the working gram capacity of the positive electrode active material.
  • an embodiment of the present application provides a secondary battery, comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, wherein the positive electrode active material layer comprises a positive electrode active material; the secondary battery satisfies: 0 ⁇ (Q 1 -Q 3 )/Q 3 ⁇ 1.0;
  • Q1 is the maximum reversible gram capacity of the positive electrode active material, in mAh/g;
  • Q3 is the working gram capacity of the positive electrode active material, in mAh/g.
  • the secondary battery further includes a negative electrode plate, the negative electrode plate includes a negative electrode collector and a negative electrode active material layer disposed on the negative electrode collector, the negative electrode active material layer includes a negative electrode active material; the secondary battery satisfies: 0.8 ⁇ (Q 2 *S 2 * ⁇ 2 )/ (Q 1 *S 1 * ⁇ 1 ) ⁇ 1.10.
  • the secondary battery satisfies: 1.1 ⁇ (Q 2 *S 2 * ⁇ 2 )/(Q 3 *S 1 * ⁇ 1 ) ⁇ 1.3;
  • S 1 is the area of the positive electrode active material layer, in m 2 ;
  • ⁇ 1 is the surface density of the positive electrode active material layer, in g/m 2 ;
  • Q2 is the maximum reversible gram capacity of the negative electrode active material, in mAh/g;
  • S 2 is the area of the negative electrode active material layer, in m 2 ;
  • ⁇ 2 is the surface density of the negative electrode active material layer, in g/m 2 .
  • the maximum reversible gram capacity Q1 of the positive electrode active material satisfies:
  • the maximum reversible gram capacity Q1 of the positive electrode active material satisfies:
  • the maximum reversible gram capacity Q2 of the negative electrode active material satisfies:
  • the working gram capacity Q3 of the positive electrode active material satisfies:
  • the surface density ⁇ 1 of the positive electrode active material layer satisfies:
  • the surface density ⁇ 2 of the negative electrode active material layer satisfies:
  • the secondary battery satisfies: 1.1 ⁇ (Q 2 * ⁇ 2 )/ (Q 3 * ⁇ 1 ) ⁇ 1.30.
  • the secondary battery satisfies: 1.14 ⁇ (Q 2 * ⁇ 2 )/ (Q 3 * ⁇ 1 ) ⁇ 1.25.
  • the positive electrode active material of the positive electrode plate includes one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.
  • the negative electrode active material of the negative electrode plate includes one or more of artificial graphite, natural graphite, amorphous carbon, carbon nanotubes, and mesophase carbon microspheres.
  • the secondary battery is charged in a constant capacity cycle.
  • the present application also provides an electrical device, comprising the secondary battery.
  • the secondary battery of the present application comprises a positive electrode plate, the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, the positive electrode active material layer comprises a positive electrode active material; a negative electrode plate, the negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, the negative electrode active material layer comprises a negative electrode active material; the secondary battery satisfies: 0 ⁇ (Q 1 -Q 3 )/Q 3 ⁇ 1.0.
  • the present application improves the cycle life of the secondary battery and enhances the electrochemical performance by adjusting the relationship between the maximum reversible gram capacity of the positive electrode active material and the working gram capacity of the positive electrode active material.
  • the present application provides a secondary battery and an electrical device. To make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail through embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
  • the secondary battery of the present application comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive current collector and a positive active material layer disposed on the positive current collector, wherein the positive active material layer comprises a positive active material; the secondary battery satisfies: 0 ⁇ (Q 1 -Q 3 )/Q 3 ⁇ 1.0.
  • Q1 is the maximum reversible gram capacity of the positive electrode active material, in units of mAh/g;
  • Q3 is the working gram capacity of the positive electrode active material, in units of mAh/g.
  • the present application improves the cycle storage life of the secondary battery by designing a redundant positive electrode while ensuring the energy density of the secondary battery.
  • the performance parameters of the secondary battery are within this range, which can increase the cycle storage life of the secondary battery and have higher energy efficiency.
  • the cycle storage life of the secondary battery can be improved while improving the energy efficiency.
  • the value of (Q 1 -Q 3 )/Q 3 can be any value among 0.05, 0.10, 0.13, 0.15, 0.17, 0.20, 0.22, 0.23, 0.25, 0.27, 0.29, 0.30, 0.32, 0.34, 0.35, 0.37, 0.40, 0.43, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.0, or a range between any two values.
  • the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 130 ⁇ Q 1 ⁇ 215. In some embodiments, the maximum reversible gram capacity Q 1 of the positive electrode active material (unit: mAh/g) is any value among 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 190, 200, 205, 210, 215, or a range between any two values.
  • the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 140 ⁇ Q 1 ⁇ 200.
  • the maximum reversible gram capacity Q 1 of the positive electrode active material of the present application is within this range, which can make the secondary battery have a higher energy density.
  • the working gram capacity Q 3 of the positive electrode active material satisfies: 65 ⁇ Q 3 ⁇ 200.
  • the working gram capacity Q 3 of the positive electrode active material of the present application is within this range, so that the secondary battery can have both the life and energy density of the secondary battery.
  • the working gram capacity Q 3 (mAh/g) of the positive electrode active material is any value among 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, or a range between any two values.
  • the working gram capacity Q 3 of the positive electrode active material satisfies: 10 6 ⁇ Q 3 ⁇ 123.
  • the reversible gram capacity Q1 of the positive electrode active material is determined by the following method:
  • the reversible gram capacity of the positive electrode active material is calculated as follows: retain one side of the positive electrode active material layer per unit area of the positive electrode plate, assemble it into a button cell with a lithium sheet, a separator, and an electrolyte, charge it to 4.35V at 0.1C, keep the voltage constant at 50 ⁇ A, and discharge it to 2.0V at 0.1C.
  • the resulting discharge capacity is X 1 .
  • the mass of the positive electrode active material in the positive electrode active material layer per unit area is found to be m 1 through chemical testing, that is, the reversible gram capacity of the positive electrode plate active material is X 1 /m 1 .
  • the working gram capacity Q3 of the positive electrode active material is determined by the following method:
  • the working capacity of a secondary battery is the nominal capacity of the secondary battery, that is, the capacity given in the specification of a commercial secondary battery is X 2 .
  • the mass of the positive active material contained in a single secondary battery is m 2 through chemical testing, and the working gram capacity of the positive electrode active material is X 2 /m 2 .
  • a secondary battery includes a negative electrode sheet, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, and the negative electrode active material layer includes a negative electrode active material.
  • the secondary battery satisfies: 0.8 ⁇ (Q 2 *S 2 * ⁇ 2 )/ (Q 1 *S 1 * ⁇ 1 ) ⁇ 1.10.
  • the secondary battery of the present application is within this range, ensuring that the positive electrode of the secondary battery has sufficient surplus lithium when it is designed, so as to supplement the active lithium consumption of the secondary battery during operation and improve the cycle and storage life of the secondary battery.
  • the secondary battery satisfies: 1.1 ⁇ (Q 2 *S 2 * ⁇ 2 )/(Q 3 *S 1 * ⁇ 1 ) ⁇ 1.3.
  • the secondary battery of the present application is within this range, ensuring that the negative electrode of the secondary battery has sufficient lithium insertion sites during operation, and the life of the secondary battery is not affected by lithium deposition due to insufficient lithium insertion sites during charging.
  • the secondary battery satisfies: S 2 >S 1 .
  • S1 is the area of the positive electrode active material layer on one side of the double-sided coating
  • S2 is the area of the negative electrode active material layer on one side of the double-sided coating.
  • S1 is the area of the positive electrode active material layer
  • S2 is the area of the negative electrode active material layer.
  • the surface density of the positive electrode active material layer is determined by the following method:
  • m 1 is the mass of the positive electrode active material layer on both sides of the positive electrode current collector, in g; S 1 is the area of the single-sided positive electrode active material layer, in m 2 .
  • m 2 is the mass of the negative electrode active material layer on both sides of the negative electrode current collector, in g; S 2 is the area of the single-sided positive electrode active material layer, in m 2 .
  • the reversible gram capacity Q2 of the negative electrode active material is determined by the following method:
  • the reversible gram capacity of the negative electrode active material is calculated as follows: retain one side of the negative electrode active material layer per unit area of the negative electrode plate, assemble it into a button battery with a lithium sheet, a separator, and an electrolyte, discharge it to 0.005V at 0.1C, discharge it to 0.005V at 0.05mA, discharge it to 0.005V at 0.02mA, and charge it to 2V at 0.1C.
  • the resulting charging capacity is X 3 .
  • the chemical method test shows that the mass of the negative electrode active material in the negative electrode active material layer per unit area is m 3 , that is, the reversible gram capacity of the negative electrode plate active material is X 3 /m 3 .
  • the secondary battery satisfies: 0.9 ⁇ S 1 /S 2 ⁇ 1.
  • the value of (Q 2 *S 2 * ⁇ 2 )/(Q 1 *S 1 * ⁇ 1 ) is: any value among 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, or a range between any two values.
  • the secondary battery of the present application can have a high cycle storage life and high energy efficiency.
  • the value of (Q 2 *S 2 * ⁇ 2 )/(Q 3 *S 1 * ⁇ 1 ) is any value among 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, or a range between any two values.
  • the secondary battery of the present application can have a good balance between cycle storage life and energy efficiency.
  • the maximum reversible gram capacity Q 2 of the negative electrode active material satisfies: 300 ⁇ Q 2 ⁇ 400.
  • the maximum reversible gram capacity Q 2 of the secondary battery of the present application is within this range, so that the secondary battery can have good kinetic performance while ensuring energy density.
  • the maximum reversible gram capacity Q 2 (unit: mAh/g) of the negative electrode active material is any value among 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, or a range between any two values.
  • the surface density ⁇ 1 of the positive electrode active material layer satisfies: 180 ⁇ 1 ⁇ 500.
  • the secondary battery can have good dynamic performance while ensuring energy density.
  • the areal density ⁇ 1 (g/m 2 ) of the positive electrode active material layer is any value among 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, or a range between any two values.
  • the surface density ⁇ 2 of the negative electrode active material layer satisfies: 50 ⁇ 2 ⁇ 250.
  • the secondary battery can have good kinetic performance while ensuring energy density.
  • the area density ⁇ 2 (g/m 2 ) of the negative electrode active material layer is any value among 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250 or a range between any two values.
  • the secondary battery satisfies: 1.1 ⁇ (Q 2 * ⁇ 2 )/ (Q 3 * ⁇ 1 ) ⁇ 1.30.
  • the secondary battery of the present application meets the above range and has the following effects: (1) ensuring that lithium will not be deposited in the secondary battery during charging, thereby extending the cycle and storage life of the secondary battery; and (2) avoiding the presence of a large number of excess lithium insertion vacancies in the negative electrode during the operation of the secondary battery, which increases the cost.
  • the value of (Q 2 * ⁇ 2 )/ (Q 3 * ⁇ 1 ) is any value among 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, or a range between any two values.
  • the secondary battery satisfies: 1.14 ⁇ (Q 2 * ⁇ 2 )/ (Q 3 * ⁇ 1 ) ⁇ 1.25.
  • the secondary battery of the present application satisfies this range, and can further achieve the following effects: the secondary battery can well balance the cycle storage life and energy efficiency.
  • the positive electrode active material includes one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.
  • the negative electrode active material includes one or more of artificial graphite, natural graphite, amorphous carbon, carbon nanotubes and mesophase carbon microspheres.
  • the preparation process of the positive electrode sheet may include steps such as stirring, coating, drying, cold pressing, striping and cutting.
  • the positive electrode sheet includes positive electrode active materials, conductive agents, binders, dispersants, etc., wherein the positive electrode active material content is 80%-99%, the binder content is 1%-6%, the conductive agent content is 0%-20%, and the dispersant content is 0%-8%.
  • the type and content of the conductive agent and the binder are not subject to specific restrictions and can be selected according to actual needs.
  • the conductive agent may include conductive carbon black, carbon nanotubes, graphene, etc.
  • the binder may include polyvinylidene fluoride.
  • the preparation of the positive electrode sheet includes: dispersing the above-mentioned positive electrode active material, conductive agent, and binder in N-methylpyrrolidone (NMP) in a certain proportion, coating the obtained slurry on aluminum foil, drying, and then cold pressing and slitting to obtain the positive electrode sheet.
  • NMP N-methylpyrrolidone
  • the negative electrode sheet includes a negative electrode active material, a binder and a conductive agent.
  • the types and contents of the negative electrode active material, the binder and the conductive agent are not particularly limited and can be selected according to actual needs.
  • the negative electrode active material includes one or more of artificial graphite, natural graphite, mesophase carbon microspheres, amorphous carbon, lithium titanate or silicon-carbon alloy.
  • graphite, a negative electrode dispersant, a negative electrode conductive agent, a negative electrode binder and a negative electrode solvent are mixed to form a negative electrode slurry, and the negative electrode slurry is coated on the surface of the negative electrode current collector to obtain a negative electrode sheet.
  • the main components of the electrolyte include lithium salts and organic solvents, and may also include additive components.
  • the types and compositions of the lithium salts and organic solvents are not particularly limited and may be selected according to actual needs.
  • the lithium salts may include lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide
  • the solvents may include ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, and propyl propionate
  • the additives may include lithium difluorophosphate, lithium bis(oxalatoborate), lithium tetrafluoroborate, vinyl sulfate, and the like.
  • the type of the isolation film is not particularly limited and can be selected according to actual needs.
  • the isolation film can be a polypropylene film, a polyethylene film, a polyvinylidene fluoride, a spandex film, an aramid film, or a multi-layer composite film modified by a coating.
  • the preparation of a secondary battery includes: assembling a positive electrode plate, a negative electrode plate, a separator and other battery components, and obtaining a secondary battery through processes such as shaping, baking, packaging, liquid injection, formation, and capacity division.
  • the battery types include soft packs, cylinders, aluminum shells, etc.
  • the designed CB value of the battery satisfies 0.8 ⁇ CB ⁇ 1.10.
  • the secondary battery adopts constant capacity cycle charging, and the charging strategy of the battery is controlled to strictly control the charging capacity of the battery so that the actual use CB value of the battery is stabilized at 1.10 ⁇ 1.30.
  • the present application provides an electrical device, which includes the above-mentioned secondary battery.
  • the electrical device can be used for but not limited to backup power supplies, motors, electric vehicles, electric motorcycles, power-assisted bicycles, bicycles, power tools, large household batteries, etc.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • the positive electrode active material lithium iron phosphate
  • conductive agent conductive carbon black SP
  • binder PVDF
  • NMP was added as a solvent for mixing. After stirring for a certain period of time, a uniform positive electrode slurry with a certain fluidity was obtained; the positive electrode slurry was evenly coated on the positive electrode current collector carbon-coated aluminum foil, and then transferred to a 110°C oven for drying, and then rolled, slit and cut into pieces to obtain a positive electrode sheet.
  • the negative electrode active material graphite
  • conductive agent conductive carbon black SP
  • thickener CMC
  • binder SBR
  • a 16 ⁇ m PP material with adhesive separator is selected as the isolation membrane, and the above-mentioned positive electrode sheet, isolation membrane, and negative electrode sheet are stacked in order, and then wound into a square bare battery cell and placed in an aluminum-plastic film. After baking at 85°C to remove moisture, a certain amount of organic electrolyte is injected and sealed. After standing, hot and cold pressing, formation, secondary sealing, and capacity division, a finished secondary battery is obtained.
  • Q 1 of the secondary battery is 130 mAh/g
  • Q 3 is 123 mAh/g
  • Q 2 is 300 mAh/g
  • (Q 1 -Q 3 )/Q 3 is 0.06
  • S 1 is 1.99 m 2
  • S 2 is 2.0 m 2
  • (Q 2 *S 2 * ⁇ 2 )/(Q 3 *S 1 * ⁇ 1 ) is 1.10
  • (Q 2 *S 2 * ⁇ 2 )/(Q 1 *S 1 * ⁇ 1 ) is 1.10.
  • Examples 2 to 4 were prepared according to the method of Example 1, Q 1 was controlled by selecting the particle size of the positive electrode active material, Q 2 of gram capacity was adjusted by the particle size and graphitization degree of the negative electrode active material, and Q 3 was determined by controlling the charge capacity.
  • the parameters of Examples 2 to 4 are shown in Table 1.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • the ternary positive electrode material lithium nickel cobalt manganese oxide
  • conductive agent conductive carbon black SP
  • binder PVDF
  • NMP is added as a solvent for mixing. After stirring for a certain period of time, a uniform positive electrode slurry with a certain fluidity is obtained; the positive electrode slurry is evenly coated on the positive electrode current collector carbon-coated aluminum foil, and then transferred to a 110°C oven for drying, and then rolled, slit, and cut into pieces to obtain a positive electrode sheet.
  • the negative electrode active material graphite
  • conductive agent conductive carbon black SP
  • thickener CMC
  • binder SBR
  • a 16 ⁇ m PP material with adhesive separator is selected as the isolation membrane, and the above-mentioned positive electrode sheet, isolation membrane, and negative electrode sheet are stacked in order, and then wound into a square bare battery cell and placed in an aluminum-plastic film. After baking at 85°C to remove moisture, a certain amount of organic electrolyte is injected and sealed. After standing, hot and cold pressing, formation, secondary sealing, and capacity division, a finished secondary battery is obtained.
  • Example 6 to Example 18 Example 6 to Example 18 were prepared according to the method of Example 5, and Q 1 was controlled by adjusting the ratio of nickel, cobalt and manganese in the positive electrode active material lithium nickel cobalt manganese oxide, and the gram capacity Q 2 was adjusted by the particle size and graphitization degree of the negative electrode active material. Q 3 was determined by controlling the charging capacity.
  • the parameters of Example 6 to Example 18 are shown in Table 1.
  • Example 19 was prepared according to the method of Example 14. The parameters of Example 19 are shown in Table 1.
  • Example 20 Example 20 was prepared according to the method of Example 14. The parameters of Example 20 are shown in Table 1.
  • Example 21 Example 21 was prepared according to the method of Example 14. The parameters of Example 21 are shown in Table 1.
  • Example 22 Example 22 was prepared according to the method of Example 14. The parameters of Example 22 are shown in Table 1.
  • Comparative Example 1 Comparative Example 1 was prepared according to the method of Example 1. The parameters of Comparative Example 1 are shown in Table 1.
  • Comparative Example 2 Comparative Example 2 was prepared according to the method of Example 5. The parameters of Comparative Example 2 are shown in Table 1.
  • Capacity retention rate The nominal capacity of the secondary battery is C 1 .
  • the discharge capacity C 2 is obtained by the number of cycles corresponding to 1C/1C cycle at a certain temperature (25°C).
  • Capacity retention rate C 2 /C 1 ⁇ 100%.
  • Energy efficiency The percentage of energy output when a lithium-ion battery is discharged compared to the energy input when it was previously charged.
  • the secondary battery is charged at a constant current of 1C to the nominal capacity of the battery, and the charging energy is recorded as E 1 ;
  • the energy efficiency value of a secondary battery is E 2 /E 1 .
  • Example 1 130 123 300 0.06 1.99 2.0 0.995 500 224 1.10 1.04 67.3 93.4
  • Example 2 135 122 305 0.11 1.98 2.0 0.99 480 212 1.12 1.01 69.8 93.5
  • Example 3 140 121 310 0.16 1.97 2.0 0.985 460 200 1.13 0.98 72.6 93.7
  • Example 4 145 120 315 0.21 1.96 2.0 0.98 440 188 1.14 0.95 74.1 93.8
  • Example 5 150 118 320 0.27 1.95 2.0 0.975 420 175 1.16 0.91 76.3 93.9
  • Example 6 155 117 325 0.33 1.94 2.0 0.97 400 164 1.17 0.
  • Example 19 Compared with Example 14, in Example 19, since S 1 /S 2 is less than 0.9, the surplus amount of the negative electrode plate is too large, resulting in an increase in the active lithium consumed due to the generation of SEI during the charge and discharge process of the secondary battery, so the cycle capacity retention rate and energy efficiency are both deteriorated; in Example 20, since S 1 /S 2 is equal to 1, which is greater than the range value of S 1 /S 2 , the negative electrode plate may not be able to completely cover the positive electrode during the manufacture of the battery cell, resulting in the possibility of lithium deposition at the negative electrode during the charging process, so the cycle capacity retention rate and energy efficiency are both deteriorated.
  • Example 21 Compared with Example 14, in Example 21, since ⁇ 1 and ⁇ 2 are both larger than their respective design ranges, the kinetics of the positive and negative electrode sheets deteriorate, affecting the lithium ion deintercalation during the operation of the secondary battery, so the cycle capacity retention rate and the energy efficiency are both deteriorated; in Example 22, since ⁇ 1 and ⁇ 2 are both smaller than their respective design ranges, the lithium deintercalation rates of the positive and negative electrode sheets are unbalanced, which increases the side reactions during the operation of the secondary battery, so the cycle capacity retention rate and the energy efficiency are both deteriorated.

Landscapes

  • 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)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

Disclosed are a secondary battery and an electric device. The secondary battery comprises a positive electrode plate. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, which is arranged on the positive electrode current collector, and the positive electrode active material layer comprises a positive electrode active material. The secondary battery satisfies: 0 < (Q1 - Q3)/Q3 ≤ 1.0. By adjusting the relationship between the maximum reversible gram capacity of the positive electrode active material and the working gram capacity of the positive electrode active material in the present application, the cycling and service life of the secondary battery are improved.

Description

一种二次电池及用电设备Secondary battery and electrical equipment
本申请要求于2022年10月27日提交中国专利局、申请号为202211340052.4、发明名称为“一种二次电池及用电设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application filed with the China Patent Office on October 27, 2022, with application number 202211340052.4 and invention name “A secondary battery and electrical equipment”, all contents of which are incorporated by reference in this application.
技术领域Technical Field
本申请涉及电池技术领域，具体涉及一种二次电池及用电设备。The present application relates to the field of battery technology, and in particular to a secondary battery and an electrical device.
背景技术Background technique
锂离子电池在储能领域优势巨大，但在实际应用中仍存在一些问题，以磷酸铁锂电池为例，磷酸铁锂单体电池的使用寿命为4000-6000次，很难满足对寿命要求较高的储能项目20-30年使用寿命（循环次数超过10000次）的要求，活性锂损失是储能锂离子电池寿命衰减的主要因素。在电池循环脱嵌锂过程中，由于石墨的膨胀收缩、正极过渡金属溶出等原因，造成SEI的破裂和生成，SEI膜面积和厚度增加，消耗电池体系有限的活性锂，最终导致电池使用寿命缩短。如何减少和补充电池衰减过程中的活性锂消耗，是提升磷酸铁锂电池寿命的关键问题。Lithium-ion batteries have great advantages in the field of energy storage, but there are still some problems in practical applications. Taking lithium iron phosphate batteries as an example, the service life of lithium iron phosphate single cells is 4,000-6,000 times, which is difficult to meet the requirements of 20-30 years of service life (more than 10,000 cycles) for energy storage projects with high life requirements. Active lithium loss is the main factor in the life decay of energy storage lithium-ion batteries. During the battery cycle and lithium insertion and extraction process, due to the expansion and contraction of graphite, the dissolution of positive transition metals and other reasons, SEI ruptures and forms, the area and thickness of the SEI film increase, and the limited active lithium in the battery system is consumed, which ultimately shortens the battery life. How to reduce and supplement the consumption of active lithium during battery decay is a key issue in improving the life of lithium iron phosphate batteries.
为了解决此类问题，常见的方式是对负极进行“补锂”，但是当前的补锂方式很难解决二次电池的循环和使用寿命问题。In order to solve such problems, a common approach is to "replenish lithium" to the negative electrode, but the current lithium replenishment method can hardly solve the problems of cycle and service life of secondary batteries.
技术问题technical problem
本申请的目的在于提供一种二次电池，通过调整正极活性材料的最大可逆克容量以及正极活性材料的工作克容量之间的关系，提升二次电池的循环和使用寿命。The purpose of the present application is to provide a secondary battery, which improves the cycle and service life of the secondary battery by adjusting the relationship between the maximum reversible gram capacity of the positive electrode active material and the working gram capacity of the positive electrode active material.
技术解决方案Technical Solutions
第一方面，本申请实施例提供一种二次电池，包括正极极片，所述正极极片包括正极集流体和设置于所述正极集流体上的正极活性材料层，所述正极活性材料层包括正极活性材料；所述二次电池满足：0＜(Q 1-Q 3)/Q 3≤1.0； In a first aspect, an embodiment of the present application provides a secondary battery, comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, wherein the positive electrode active material layer comprises a positive electrode active material; the secondary battery satisfies: 0＜(Q 1 -Q 3 )/Q 3 ≤1.0;
其中，Q 1为正极活性材料的最大可逆克容量，单位为mAh/g； Where Q1 is the maximum reversible gram capacity of the positive electrode active material, in mAh/g;
Q 3为正极活性材料的工作克容量，单位为mAh/g。 Q3 is the working gram capacity of the positive electrode active material, in mAh/g.
在一些实施例中，所述二次电池还包括负极极片，所述负极极片包括负极集流体和设置于所述负极集流体上的负极活性材料层，所述负极活性材料层包括负极活性材料；所述二次电池满足：0.8≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10。 In some embodiments, the secondary battery further includes a negative electrode plate, the negative electrode plate includes a negative electrode collector and a negative electrode active material layer disposed on the negative electrode collector, the negative electrode active material layer includes a negative electrode active material; the secondary battery satisfies: 0.8≤(Q 2 *S 2 *σ 2 )/ (Q 1 *S 1 *σ 1 )≤1.10.
在一些实施例中，所述二次电池满足：1.1≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.3; In some embodiments, the secondary battery satisfies: 1.1≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.3;
其中，S 2＞S 1； Among them, S 2 >S 1 ;
S 1为正极活性材料层的面积，单位为m 2； S 1 is the area of the positive electrode active material layer, in m 2 ;
σ 1为正极活性材料层的面密度，单位为g/m 2； σ 1 is the surface density of the positive electrode active material layer, in g/m 2 ;
Q 2为负极活性材料的最大可逆克容量，单位为mAh/g； Q2 is the maximum reversible gram capacity of the negative electrode active material, in mAh/g;
S 2为负极活性材料层的面积，单位为m 2； S 2 is the area of the negative electrode active material layer, in m 2 ;
σ 2为负极活性材料层的面密度，单位为g/m 2。 σ 2 is the surface density of the negative electrode active material layer, in g/m 2 .
在一些实施例中，0.05≤(Q 1-Q 3)/Q 3≤0.8。 In some embodiments, 0.05≤(Q 1 −Q 3 )/Q 3 ≤0.8.
在一些实施例中，0.1≤(Q 1-Q 3)/Q 3≤0.45。 In some embodiments, 0.1≤(Q 1 −Q 3 )/Q 3 ≤0.45.
在一些实施例中，0.9≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10。 In some embodiments, 0.9≤(Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 )≤1.10.
在一些实施例中，1.0≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.05。 In some embodiments, 1.0≤(Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 )≤1.05.
在一些实施例中，1.16≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.25。 In some embodiments, 1.16≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.25.
在一些实施例中，所述正极活性材料的最大可逆克容量Q 1满足： In some embodiments, the maximum reversible gram capacity Q1 of the positive electrode active material satisfies:
130≤Q 1≤215。 130≤Q 1 ≤215.
在一些实施例中，所述正极活性材料的最大可逆克容量Q 1满足： In some embodiments, the maximum reversible gram capacity Q1 of the positive electrode active material satisfies:
140≤ Q 1 ≤200。 140≤ Q 1 ≤200.
在一些实施例中，所述负极活性材料的最大可逆克容量Q 2满足： In some embodiments, the maximum reversible gram capacity Q2 of the negative electrode active material satisfies:
300≤Q 2≤400。 300≤Q 2 ≤400.
在一些实施例中，所述正极活性材料的工作克容量Q 3满足： In some embodiments, the working gram capacity Q3 of the positive electrode active material satisfies:
65≤Q 3≤200。 65≤Q 3 ≤200.
在一些实施例中，所述正极活性材料层的面密度σ 1满足： In some embodiments, the surface density σ 1 of the positive electrode active material layer satisfies:
180≤σ 1≤500。 180≤σ 1 ≤500.
在一些实施例中，所述负极活性材料层的面密度σ 2满足： In some embodiments, the surface density σ 2 of the negative electrode active material layer satisfies:
50≤σ 2≤250。 50≤σ 2 ≤250.
在一些实施例中，所述二次电池满足：1.1＜(Q 2*σ 2)/ (Q 3*σ 1)≤1.30。 In some embodiments, the secondary battery satisfies: 1.1<(Q 2 *σ 2 )/ (Q 3 *σ 1 )≤1.30.
在一些实施例中，所述二次电池满足：1.14＜(Q 2*σ 2)/ (Q 3*σ 1)≤1.25。 In some embodiments, the secondary battery satisfies: 1.14＜(Q 2 *σ 2 )/ (Q 3 *σ 1 )≤1.25.
在一些实施例中，所述正极极片的正极活性材料包括磷酸铁锂、镍钴锰酸锂、镍钴铝酸锂中的一种或多种。In some embodiments, the positive electrode active material of the positive electrode plate includes one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.
在一些实施例中，所述负极极片的负极活性材料包括人造石墨、天然石墨、无定型碳、碳纳米管和中间相炭微球中的一种或多种。In some embodiments, the negative electrode active material of the negative electrode plate includes one or more of artificial graphite, natural graphite, amorphous carbon, carbon nanotubes, and mesophase carbon microspheres.
在一些实施例中，所述二次电池选用定容循环充电。In some embodiments, the secondary battery is charged in a constant capacity cycle.
第二方面，本申请还提供一种用电设备，包括所述二次电池。In a second aspect, the present application also provides an electrical device, comprising the secondary battery.
有益效果Beneficial Effects
本申请的二次电池，包括正极极片，正极极片包括正极集流体和设置于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材料；负极极片，负极极片包括负极集流体和设置于负极集流体上的负极活性材料层，负极活性材料层包括负极活性材料；二次电池满足：0＜(Q 1-Q 3)/Q 3≤1.0。本申请通过调整正极活性材料的最大可逆克容量以及正极活性材料的工作克容量之间的关系，提高二次电池的循环寿命，并且提升电化学性能。 The secondary battery of the present application comprises a positive electrode plate, the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, the positive electrode active material layer comprises a positive electrode active material; a negative electrode plate, the negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, the negative electrode active material layer comprises a negative electrode active material; the secondary battery satisfies: 0＜(Q 1 -Q 3 )/Q 3 ≤1.0. The present application improves the cycle life of the secondary battery and enhances the electrochemical performance by adjusting the relationship between the maximum reversible gram capacity of the positive electrode active material and the working gram capacity of the positive electrode active material.
本发明的实施方式Embodiments of the present invention
本申请提供一种二次电池及用电设备，为使本申请的目的、技术方案及效果更加清楚、明确，以下通过实施例对本申请进一步详细说明。应当理解，此处所描述的具体实施例仅用以解释本申请，并不用于限定本申请。The present application provides a secondary battery and an electrical device. To make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail through embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
二次电池Secondary battery
本申请的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于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材料；二次电池满足：0＜(Q 1-Q 3)/Q 3≤1.0。 The secondary battery of the present application comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive current collector and a positive active material layer disposed on the positive current collector, wherein the positive active material layer comprises a positive active material; the secondary battery satisfies: 0＜(Q 1 -Q 3 )/Q 3 ≤1.0.
本申请中，Q 1为正极活性材料的最大可逆克容量，单位为mAh/g；Q 3为正极活性材料的工作克容量，单位为mAh/g。 In the present application, Q1 is the maximum reversible gram capacity of the positive electrode active material, in units of mAh/g; Q3 is the working gram capacity of the positive electrode active material, in units of mAh/g.
本申请在保证二次电池能量密度的同时，通过正极富余设计，提升二次电池的循环存储寿命。The present application improves the cycle storage life of the secondary battery by designing a redundant positive electrode while ensuring the energy density of the secondary battery.
在一些实施例中，0.05≤(Q 1-Q 3)/Q 3≤0.8，二次电池的性能参数在该范围内，可以使二次电池提升循环储存寿命，同时具有较高的能量效率。 In some embodiments, 0.05≤(Q 1 -Q 3 )/Q 3 ≤0.8. The performance parameters of the secondary battery are within this range, which can increase the cycle storage life of the secondary battery and have higher energy efficiency.
在一些实施例中，0.1≤(Q 1-Q 3)/Q 3≤0.45，二次电池的性能参数在该范围内，可以使二次电池提升循环储存寿命，同时提升能量效率。 In some embodiments, 0.1≤(Q 1 −Q 3 )/Q 3 ≤0.45. When the performance parameter of the secondary battery is within this range, the cycle storage life of the secondary battery can be improved while improving the energy efficiency.
在一些实施例中，(Q 1-Q 3)/Q 3的取值可以是0.05、0.10、0.13、0.15、0.17、0.20、0.22、0.23、0.25、0.27、0.29、0.30、0.32、0.34、0.35、0.37、0.40、0.43、0.45、0.50、0.55、0.60、0.65、0.70、0.75、0.80、0.85、0.90、0.95、1.0中的任意值或任意两值之间的范围值。 In some embodiments, the value of (Q 1 -Q 3 )/Q 3 can be any value among 0.05, 0.10, 0.13, 0.15, 0.17, 0.20, 0.22, 0.23, 0.25, 0.27, 0.29, 0.30, 0.32, 0.34, 0.35, 0.37, 0.40, 0.43, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.0, or a range between any two values.
在一些实施例中，正极活性材料的最大可逆克容量Q 1满足：130≤Q 1≤215。在一些实施例中，正极活性材料的最大可逆克容量Q 1（单位mAh/g）的取值为：130、135、140、145、150、155、160、165、170、175、180、185、190、190、200、205、210、215中的任意值或任意两值之间的范围值。 In some embodiments, the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 130≤Q 1 ≤215. In some embodiments, the maximum reversible gram capacity Q 1 of the positive electrode active material (unit: mAh/g) is any value among 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 190, 200, 205, 210, 215, or a range between any two values.
在一些实施例中，正极活性材料的最大可逆克容量Q 1满足：140≤Q 1≤200。本申请正极活性材料的最大可逆克容量Q 1在该范围内，可以使得二次电池有具有较高的能量密度。 In some embodiments, the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 140≤Q 1 ≤200. The maximum reversible gram capacity Q 1 of the positive electrode active material of the present application is within this range, which can make the secondary battery have a higher energy density.
在一些实施例中，正极活性材料的工作克容量Q 3满足：65≤Q 3≤200。本申请正极活性材料的工作克容量Q 3在该范围内，可以使得二次电池有具有兼顾二次电池的寿命和能量密度。 In some embodiments, the working gram capacity Q 3 of the positive electrode active material satisfies: 65≤Q 3 ≤200. The working gram capacity Q 3 of the positive electrode active material of the present application is within this range, so that the secondary battery can have both the life and energy density of the secondary battery.
在一些实施例中，正极活性材料的工作克容量Q 3（单位mAh/g）的取值为：65、70、75、80、85、90、95、100、105、110、115、120、125、130、135、140、145、150、155、160、165、170、175、180、185、190、195、200中的任意值或任意两值之间的范围值。 In some embodiments, the working gram capacity Q 3 (mAh/g) of the positive electrode active material is any value among 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, or a range between any two values.
在一些实施例中，正极活性材料的工作克容量Q 3满足：106≤Q 3≤123。 In some embodiments, the working gram capacity Q 3 of the positive electrode active material satisfies: 10 6 ≤ Q 3 ≤123.
在一些实施例中，正极活性材料的可逆克容量Q 1通过以下方法测定： In some embodiments, the reversible gram capacity Q1 of the positive electrode active material is determined by the following method:
正极活性材料的可逆克容量的计算为：将单位面积正极极片保留一面正极活性物质层，与锂片、隔膜、电解液组装成扣式电池，0.1C充电到4.35V，恒压至50μA，0.1C放电至2.0V，所得放电容量为X 1，通过化学方法测试得出单位面积正极活性物质层中的正极活性物质的质量为m 1，即为正极极片活性材料的可逆克容量为X 1/m 1。 The reversible gram capacity of the positive electrode active material is calculated as follows: retain one side of the positive electrode active material layer per unit area of the positive electrode plate, assemble it into a button cell with a lithium sheet, a separator, and an electrolyte, charge it to 4.35V at 0.1C, keep the voltage constant at 50μA, and discharge it to 2.0V at 0.1C. The resulting discharge capacity is X 1 . The mass of the positive electrode active material in the positive electrode active material layer per unit area is found to be m 1 through chemical testing, that is, the reversible gram capacity of the positive electrode plate active material is X 1 /m 1 .
在一些实施例中，正极活性材料的工作克容量Q 3通过以下方法测定： In some embodiments, the working gram capacity Q3 of the positive electrode active material is determined by the following method:
二次电池工作容量即为二次电池的标称容量，即商品化二次电池规格书中给出的容量为X 2，通过化学方法测试得出单个二次电池所含正极活性物质的质量为m 2，则正极极片活性材料的工作克容量为X 2/m 2。 The working capacity of a secondary battery is the nominal capacity of the secondary battery, that is, the capacity given in the specification of a commercial secondary battery is X 2 . The mass of the positive active material contained in a single secondary battery is m 2 through chemical testing, and the working gram capacity of the positive electrode active material is X 2 /m 2 .
在一些实施例中，二次电池包括负极极片，负极极片包括负极集流体和设置于负极集流体上的负极活性材料层，负极活性材料层包括负极活性材料。In some embodiments, a secondary battery includes a negative electrode sheet, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, and the negative electrode active material layer includes a negative electrode active material.
在一些实施例中，二次电池满足：0.8≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10。 In some embodiments, the secondary battery satisfies: 0.8≤(Q 2 *S 2 *σ 2 )/ (Q 1 *S 1 *σ 1 )≤1.10.
本申请的二次电池在该范围内，确保二次电池在设计时正极有足够富余的锂，以此补充二次电池在工作过程中的活性锂消耗，提升二次电池的循环、存储寿命。The secondary battery of the present application is within this range, ensuring that the positive electrode of the secondary battery has sufficient surplus lithium when it is designed, so as to supplement the active lithium consumption of the secondary battery during operation and improve the cycle and storage life of the secondary battery.
在一些实施例中，二次电池满足：1.1≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.3。 In some embodiments, the secondary battery satisfies: 1.1≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.3.
本申请的二次电池在该范围内，确保二次电池在工作过程中负极有足够的嵌锂位点，在充电过程中不会因为嵌锂位点不足析锂而影响寿命。The secondary battery of the present application is within this range, ensuring that the negative electrode of the secondary battery has sufficient lithium insertion sites during operation, and the life of the secondary battery is not affected by lithium deposition due to insufficient lithium insertion sites during charging.
在一些实施例中，二次电池满足：S 2＞S 1。 In some embodiments, the secondary battery satisfies: S 2 >S 1 .
本申请中，S 1为正极活性材料层的面积，单位为m 2；σ 1为正极活性材料层的面密度，单位为g/m 2；Q 2为负极活性材料的最大可逆克容量，单位为mAh/g；S 2为负极活性材料层的面积，单位为m 2；σ 2为负极活性材料层的面密度，单位为g/m 2。 In the present application, S 1 is the area of the positive electrode active material layer, in m 2 ; σ 1 is the surface density of the positive electrode active material layer, in g/m 2 ; Q 2 is the maximum reversible gram capacity of the negative electrode active material, in mAh/g; S 2 is the area of the negative electrode active material layer, in m 2 ; σ 2 is the surface density of the negative electrode active material layer, in g/m 2 .
其中，当正极极片为双面涂覆时，S 1为双面涂覆中的其中一面正极活性材料层的面积；S 2为双面涂覆中的其中一面负极活性材料层的面积。 When the positive electrode plate is double-sided coated, S1 is the area of the positive electrode active material layer on one side of the double-sided coating; S2 is the area of the negative electrode active material layer on one side of the double-sided coating.
当正极极片为单面涂覆时，S 1为正极活性材料层的面积；S 2为负极活性材料层的面积。 When the positive electrode sheet is coated on one side, S1 is the area of the positive electrode active material layer; S2 is the area of the negative electrode active material layer.
在一些实施方式中，正极活性材料层的面密度通过以下方法测定：In some embodiments, the surface density of the positive electrode active material layer is determined by the following method:
正极活性材料层的面密度σ 1通过公式：σ 1＝m 1/S 1计算得出。 The surface density σ 1 of the positive electrode active material layer is calculated by the formula: σ 1 =m 1 /S 1 .
式中，m 1为正极集流体双面正极活性材料层的质量，单位为g；S 1为单面正极活性材料层的面积，单位为m 2。 Wherein, m 1 is the mass of the positive electrode active material layer on both sides of the positive electrode current collector, in g; S 1 is the area of the single-sided positive electrode active material layer, in m 2 .
负极活性材料层的面密度σ 2通过公式：σ 2＝m 2/S 2计算得出。 The surface density σ 2 of the negative electrode active material layer is calculated by the formula: σ 2 =m 2 /S 2 .
式中，m 2为负极集流体双面负极活性材料层的质量，单位为g；S 2为单面正极活性材料层的面积，单位为m 2。 Wherein, m 2 is the mass of the negative electrode active material layer on both sides of the negative electrode current collector, in g; S 2 is the area of the single-sided positive electrode active material layer, in m 2 .
在一些实施例中，负极活性材料的可逆克容量Q 2通过以下方法测定： In some embodiments, the reversible gram capacity Q2 of the negative electrode active material is determined by the following method:
负极活性材料的可逆克容量的计算为：将单位面积负极极片保留一面负极活性物质层，与锂片、隔膜、电解液组装成扣式电池，0.1C放电至0.005V，0.05mA放电至0.005V，0.02mA放电至0.005V，0.1C充电至2V，所得充电容量为X 3，通过化学方法测试得出单位面积负极活性物质层中的负极活性物质的质量为m 3，即为负极极片活性材料的可逆克容量为X 3/m 3。 The reversible gram capacity of the negative electrode active material is calculated as follows: retain one side of the negative electrode active material layer per unit area of the negative electrode plate, assemble it into a button battery with a lithium sheet, a separator, and an electrolyte, discharge it to 0.005V at 0.1C, discharge it to 0.005V at 0.05mA, discharge it to 0.005V at 0.02mA, and charge it to 2V at 0.1C. The resulting charging capacity is X 3 . The chemical method test shows that the mass of the negative electrode active material in the negative electrode active material layer per unit area is m 3 , that is, the reversible gram capacity of the negative electrode plate active material is X 3 /m 3 .
在一些实施例中，二次电池满足：0.9≤S 1/S 2＜1。 In some embodiments, the secondary battery satisfies: 0.9≤S 1 /S 2 <1.
在一些实施例中，(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)的取值为：0.80、0.81、0.82、0.83、0.84、0.85、0.86、0.87、0.88、0.89、0.90、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98、0.99、1.00、1.01、1.02、1.03、1.04、1.05、1.06、1.07、1.08、1.09、1.10中的任意值或任意两值之间的范围值。 In some embodiments, the value of (Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 ) is: any value among 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, or a range between any two values.
在一些实施例中，0.9≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10。本申请的二次电池在该范围内，可以使得二次电池同时兼顾循环存储寿命和能量效率。 In some embodiments, 0.9≤(Q 2 *S 2 *σ 2 )/ (Q 1 *S 1 *σ 1 )≤1.10. When the secondary battery of the present application is within this range, the secondary battery can take both cycle storage life and energy efficiency into consideration.
在一些实施例中，1.0≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.05。本申请的二次电池在该范围内，可以使得二次电池有具有高的循环存储寿命和高的能量效率。 In some embodiments, 1.0≤(Q 2 *S 2 *σ 2 )/ (Q 1 *S 1 *σ 1 )≤1.05. When the secondary battery of the present application is within this range, the secondary battery can have a high cycle storage life and high energy efficiency.
在一些实施例中，（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）的取值为：1.10、1.11、1.12、1.13、1.14、1.15、1.16、1.17、1.18、1.19、1.20、1.21、1.22、1.23、1.24、1.25、1.26、1.27、1.28、1.29、1.30中的任意值或任意两值之间的范围值。 In some embodiments, the value of (Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 ) is any value among 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, or a range between any two values.
在一些实施例中，1.16≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.25。本申请的二次电池在该范围内，可以使得二次电池很好兼顾循环存储寿命和能量效率。 In some embodiments, 1.16≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.25. When the secondary battery of the present application is within this range, the secondary battery can have a good balance between cycle storage life and energy efficiency.
在一些实施例中，负极活性材料的最大可逆克容量Q 2满足：300≤Q 2≤400。本申请的二次电池的最大可逆克容量Q 2在该范围内，可以使得二次电池在保证能量密度的同时具有较好的动力学性能。 In some embodiments, the maximum reversible gram capacity Q 2 of the negative electrode active material satisfies: 300≤Q 2 ≤400. The maximum reversible gram capacity Q 2 of the secondary battery of the present application is within this range, so that the secondary battery can have good kinetic performance while ensuring energy density.
在一些实施例中，负极活性材料的最大可逆克容量Q 2（单位mAh/g）的取值为：300、310、320、330、340、350、360、370、380、390、400中的任意值或任意两值之间的范围值。 In some embodiments, the maximum reversible gram capacity Q 2 (unit: mAh/g) of the negative electrode active material is any value among 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, or a range between any two values.
在一些实施例中，正极活性材料层的面密度σ 1满足：180≤σ 1≤500。本申请的正极活性材料层的面密度σ 1在该范围内，可以使得二次电池在保证能量密度的同时具有较好的动力学性能。 In some embodiments, the surface density σ 1 of the positive electrode active material layer satisfies: 180≤σ 1 ≤500. When the surface density σ 1 of the positive electrode active material layer of the present application is within this range, the secondary battery can have good dynamic performance while ensuring energy density.
在一些实施例中，正极活性材料层的面密度σ 1（g/m 2）的取值为：180、190、200、210、220、230、240、250、260、270、280、290、300、310、320、330、340、350、360、370、380、390、400、410、420、430、440、450、460、470、480、490、500中的任意值或任意两值之间的范围值。 In some embodiments, the areal density σ 1 (g/m 2 ) of the positive electrode active material layer is any value among 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, or a range between any two values.
在一些实施例中，负极活性材料层的面密度σ 2满足：50≤σ 2≤250。本申请的负极活性材料层的面密度σ 2在该范围内，可以使得二次电池在保证能量密度的同时具有较好的动力学性能。 In some embodiments, the surface density σ 2 of the negative electrode active material layer satisfies: 50≤σ 2 ≤250. When the surface density σ 2 of the negative electrode active material layer of the present application is within this range, the secondary battery can have good kinetic performance while ensuring energy density.
在一些实施例中，负极活性材料层的面密度σ 2（g/m 2）的取值为：50、60、70、80、90、100、110、120、130、140、150、160、170、180、190、200、210、220、230、240、250中的任意值或任意两值之间的范围值。 In some embodiments, the area density σ 2 (g/m 2 ) of the negative electrode active material layer is any value among 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250 or a range between any two values.
在一些实施例中，二次电池满足：1.1＜(Q 2*σ 2)/ (Q 3*σ 1)≤1.30。 In some embodiments, the secondary battery satisfies: 1.1<(Q 2 *σ 2 )/ (Q 3 *σ 1 )≤1.30.
本申请的二次电池满足上述范围具有以下效果：（1）确保二次电池在充电过程中不会析锂，延长二次电池的循环、存储寿命；（2）避免二次电池工作过程中负极存在大量过剩的嵌锂空位，额外增加成本。The secondary battery of the present application meets the above range and has the following effects: (1) ensuring that lithium will not be deposited in the secondary battery during charging, thereby extending the cycle and storage life of the secondary battery; and (2) avoiding the presence of a large number of excess lithium insertion vacancies in the negative electrode during the operation of the secondary battery, which increases the cost.
在一些实施例中，(Q 2*σ 2)/ (Q 3*σ 1)的取值为：1.11、1.12、1.13、1.14、1.15、1.16、1.17、1.18、1.19、1.20、1.21、1.22、1.23、1.24、1.25、1.26、1.27、1.28、1.29、1.30中的任意值或任意两值之间的范围值。 In some embodiments, the value of (Q 2 *σ 2 )/ (Q 3 *σ 1 ) is any value among 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.30, or a range between any two values.
在一些实施例中，二次电池满足：1.14＜(Q 2*σ 2)/ (Q 3*σ 1) ≤1.25。本申请的二次电池满足该范围，可以进一步取得以下效果：可以使得二次电池很好兼顾循环存储寿命和能量效率。 In some embodiments, the secondary battery satisfies: 1.14＜(Q 2 *σ 2 )/ (Q 3 *σ 1 ) ≤1.25. The secondary battery of the present application satisfies this range, and can further achieve the following effects: the secondary battery can well balance the cycle storage life and energy efficiency.
正极活性材料包括磷酸铁锂、镍钴锰酸锂、镍钴铝酸锂中的一种或多种。The positive electrode active material includes one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.
负极活性材料包括人造石墨、天然石墨、无定型碳、碳纳米管和中间相炭微球中的一种或多种。The negative electrode active material includes one or more of artificial graphite, natural graphite, amorphous carbon, carbon nanotubes and mesophase carbon microspheres.
正极极片Positive electrode
在一些实施例中，正极极片的制备工艺可包括搅拌、涂布、干燥、冷压、分条以及裁片等步骤。正极极片包括正极活性材料、导电剂、粘结剂、分散剂等，其中，正极活性材料含量80%-99%，粘结剂含量1%-6%，导电剂含量0%-20%，分散剂0%-8%，通过上述含量的分配在保证二次电池能量密度的同时，改善二次电池体系动力学，平衡正负极脱嵌锂速率，抑制负极嵌锂过程中过度膨胀，减少活性锂损失，提升循环寿命。其中，导电剂以及粘结剂的种类和含量不受具体的限制，可根据实际需求进行选择。在一些实施例中，导电剂可以包括导电炭黑、碳纳米管、石墨烯等，粘结剂可以包括聚偏氟乙烯。In some embodiments, the preparation process of the positive electrode sheet may include steps such as stirring, coating, drying, cold pressing, striping and cutting. The positive electrode sheet includes positive electrode active materials, conductive agents, binders, dispersants, etc., wherein the positive electrode active material content is 80%-99%, the binder content is 1%-6%, the conductive agent content is 0%-20%, and the dispersant content is 0%-8%. Through the distribution of the above contents, while ensuring the energy density of the secondary battery, the dynamics of the secondary battery system is improved, the positive and negative electrode lithium deintercalation rates are balanced, the excessive expansion during the negative electrode lithium intercalation process is suppressed, the loss of active lithium is reduced, and the cycle life is improved. Among them, the type and content of the conductive agent and the binder are not subject to specific restrictions and can be selected according to actual needs. In some embodiments, the conductive agent may include conductive carbon black, carbon nanotubes, graphene, etc., and the binder may include polyvinylidene fluoride.
在一些实施例中，正极极片的制备包括：将上述正极活性材料、导电剂、粘结剂按一定的比例分散于N-甲基吡咯烷酮（NMP）中，将所得的浆料涂布于铝箔上，经过干燥，然后经过冷压、分条得到正极极片。In some embodiments, the preparation of the positive electrode sheet includes: dispersing the above-mentioned positive electrode active material, conductive agent, and binder in N-methylpyrrolidone (NMP) in a certain proportion, coating the obtained slurry on aluminum foil, drying, and then cold pressing and slitting to obtain the positive electrode sheet.
负极极片Negative electrode
在一些实施例中，负极极片包括负极活性材料、粘结剂和导电剂。负极活性材料、粘结剂和导电剂的种类和含量并不受特别的限制，可根据实际需求进行选择。在一些实施例中，负极活性材料包括人造石墨、天然石墨、中间相碳微球、无定形碳、钛酸锂或硅碳合金中的一种或多种。在一些实施例中，将石墨、负极分散剂、负极导电剂、负极粘结剂和负极溶剂混合制成负极浆料，将负极浆料涂布于负极集流体表面，得到负极极片。In some embodiments, the negative electrode sheet includes a negative electrode active material, a binder and a conductive agent. The types and contents of the negative electrode active material, the binder and the conductive agent are not particularly limited and can be selected according to actual needs. In some embodiments, the negative electrode active material includes one or more of artificial graphite, natural graphite, mesophase carbon microspheres, amorphous carbon, lithium titanate or silicon-carbon alloy. In some embodiments, graphite, a negative electrode dispersant, a negative electrode conductive agent, a negative electrode binder and a negative electrode solvent are mixed to form a negative electrode slurry, and the negative electrode slurry is coated on the surface of the negative electrode current collector to obtain a negative electrode sheet.
电解液Electrolyte
在一些实施例中，电解液的主要成分包括锂盐和有机溶剂，还可以包括含有添加剂成分。其中锂盐和有机溶剂的种类和组成并不受特别的限制，可根据实际需求进行选择。其中，锂盐可以包括六氟磷酸锂以及双氟磺酰亚胺锂等，溶剂可以包括碳酸乙烯酯、碳酸甲乙酯、碳酸二甲酯以及丙酸丙酯等，添加剂可以包括二氟磷酸锂、双草酸硼酸锂、四氟硼酸锂、硫酸乙烯酯等。In some embodiments, the main components of the electrolyte include lithium salts and organic solvents, and may also include additive components. The types and compositions of the lithium salts and organic solvents are not particularly limited and may be selected according to actual needs. The lithium salts may include lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide, the solvents may include ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, and propyl propionate, and the additives may include lithium difluorophosphate, lithium bis(oxalatoborate), lithium tetrafluoroborate, vinyl sulfate, and the like.
隔离膜Isolation film
在一些实施例中，隔离膜的种类并不受特别的限制，可根据实际需求进行选择。隔离膜可以为聚丙烯膜、聚乙烯膜、聚偏氟乙烯、氨纶膜、芳纶膜或者是经过涂层改性后的多层复合膜。In some embodiments, the type of the isolation film is not particularly limited and can be selected according to actual needs. The isolation film can be a polypropylene film, a polyethylene film, a polyvinylidene fluoride, a spandex film, an aramid film, or a multi-layer composite film modified by a coating.
在一些实施例中，二次电池的制备包括：将正极极片、负极极片、隔膜和其他电池零部件进行组装，经过整形、烘烤、封装、注液、化成、分容等工序，得到二次电池，电池类型包括软包、圆柱、铝壳等。In some embodiments, the preparation of a secondary battery includes: assembling a positive electrode plate, a negative electrode plate, a separator and other battery components, and obtaining a secondary battery through processes such as shaping, baking, packaging, liquid injection, formation, and capacity division. The battery types include soft packs, cylinders, aluminum shells, etc.
在一些实施中，电池的设计CB值满足0.8≤CB≤1.10。In some implementations, the designed CB value of the battery satisfies 0.8≤CB≤1.10.
本申请中，二次电池选用定容循环充电，通过对电池的充电策略进行控制，严格控制电池的充电容量，使电池的实际使用CB值稳定在1.10~1.30。In the present application, the secondary battery adopts constant capacity cycle charging, and the charging strategy of the battery is controlled to strictly control the charging capacity of the battery so that the actual use CB value of the battery is stabilized at 1.10~1.30.
用电设备Electrical equipment
在一些实施例中，本申请提供了一种用电设备，本申请的用电设备包含了上述的二次电池，用电设备可用于但不限于备用电源、电机、电动汽车、电动摩托车、助力自行车、自行车、电动工具、家庭用大型蓄电池等。In some embodiments, the present application provides an electrical device, which includes the above-mentioned secondary battery. The electrical device can be used for but not limited to backup power supplies, motors, electric vehicles, electric motorcycles, power-assisted bicycles, bicycles, power tools, large household batteries, etc.
实施例1：Embodiment 1:
（1）按质量比97:0.7:2.3将正极活性材料（磷酸铁锂）、导电剂（导电炭黑SP）以及粘结剂（PVDF）混合制成正极浆料，加入NMP作为溶剂进行混合，搅拌一定时间后获得具有一定流动性的均匀正极浆料；将正极浆料均匀涂覆在正极集流体涂炭铝箔上，随后转移至110℃烘箱进行干燥，然后经过辊压、分条、裁片后得到正极极片。(1) The positive electrode active material (lithium iron phosphate), conductive agent (conductive carbon black SP) and binder (PVDF) were mixed in a mass ratio of 97:0.7:2.3 to prepare a positive electrode slurry, and NMP was added as a solvent for mixing. After stirring for a certain period of time, a uniform positive electrode slurry with a certain fluidity was obtained; the positive electrode slurry was evenly coated on the positive electrode current collector carbon-coated aluminum foil, and then transferred to a 110°C oven for drying, and then rolled, slit and cut into pieces to obtain a positive electrode sheet.
（2）按质量比96.5:0.5:1.2:1.8将负极活性材料（石墨）、导电剂（导电炭黑SP）、增稠剂（CMC）以及粘结剂（SBR）混合制成负极浆料，加入去离子水作为溶剂进行混合，搅拌一定时间后获得具有一定流动性的均匀负极浆料；将负极浆料均匀涂覆在负极集流体铜箔上，随后转移至120℃烘箱进行干燥，然后经过辊压、分条、裁片得到负极极片。(2) The negative electrode active material (graphite), conductive agent (conductive carbon black SP), thickener (CMC) and binder (SBR) are mixed in a mass ratio of 96.5:0.5:1.2:1.8 to prepare a negative electrode slurry, deionized water is added as a solvent for mixing, and a uniform negative electrode slurry with a certain fluidity is obtained after stirring for a certain period of time; the negative electrode slurry is evenly coated on the negative electrode current collector copper foil, and then transferred to a 120°C oven for drying, and then rolled, slit and cut into pieces to obtain a negative electrode sheet.
（3）将有机溶剂碳酸乙烯酯、碳酸甲乙酯和碳酸二甲酯按照1：1：1体积比混合。在含水量<10ppm的氩气气氛手套箱中，将干燥充分后的六氟磷酸锂溶解于上述有机溶剂中，浓度为1mol/L，混合均匀，获得电解液。(3) Organic solvents ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate were mixed in a volume ratio of 1:1:1. In an argon atmosphere glove box with a water content of <10 ppm, fully dried lithium hexafluorophosphate was dissolved in the above organic solvents to a concentration of 1 mol/L, and mixed evenly to obtain an electrolyte.
（4）选择16μm在PP材质在带胶隔膜作为隔离膜，将上述的正极极片、隔离膜、负极极片按照顺序叠好，再卷绕成方形的裸电芯后置于铝塑膜中，然后在85℃下烘烤去除水分后，注入一定量的有机电解液后封口，经静置、热冷压、化成、二封、分容等工序后，得到成品二次电池。(4) A 16 μm PP material with adhesive separator is selected as the isolation membrane, and the above-mentioned positive electrode sheet, isolation membrane, and negative electrode sheet are stacked in order, and then wound into a square bare battery cell and placed in an aluminum-plastic film. After baking at 85°C to remove moisture, a certain amount of organic electrolyte is injected and sealed. After standing, hot and cold pressing, formation, secondary sealing, and capacity division, a finished secondary battery is obtained.
其中，二次电池的Q 1为130 mAh/g，Q 3为123 mAh/g，Q 2为300mAh/g，(Q 1-Q 3)/Q 3为0.06，S 1为1.99 m 2，S 2为2.0 m 2，（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）为1.10，(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)为1.10。 Among them, Q 1 of the secondary battery is 130 mAh/g, Q 3 is 123 mAh/g, Q 2 is 300 mAh/g, (Q 1 -Q 3 )/Q 3 is 0.06, S 1 is 1.99 m 2 , S 2 is 2.0 m 2 , (Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 ) is 1.10, and (Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 ) is 1.10.
实施例2~实施例4：按照实施例1的方法制备实施例2~4，通过正极材料活性材料的粒径选择来控制Q 1，通过负极活性材料的粒径和石墨化度来调节克容量的Q 2，通过充电容量的控制来确定Q 3，实施例2~实施例4的参数如表1所示。 Examples 2 to 4: Examples 2 to 4 were prepared according to the method of Example 1, Q 1 was controlled by selecting the particle size of the positive electrode active material, Q 2 of gram capacity was adjusted by the particle size and graphitization degree of the negative electrode active material, and Q 3 was determined by controlling the charge capacity. The parameters of Examples 2 to 4 are shown in Table 1.
实施例5：Embodiment 5:
（1）按质量比为96:1:3将三元正极材料（镍钴锰酸锂）、导电剂（导电炭黑SP）、粘结剂（PVDF）混合制成正极浆料，加入NMP作为溶剂进行混合，搅拌一定时间后获得具有一定流动性的均匀正极浆料；将正极浆料均匀涂覆在正极集流体涂炭铝箔上，随后转移至110℃烘箱进行干燥，然后经过辊压、分条、裁片后得到正极极片。(1) The ternary positive electrode material (lithium nickel cobalt manganese oxide), conductive agent (conductive carbon black SP), and binder (PVDF) are mixed in a mass ratio of 96:1:3 to prepare a positive electrode slurry, and NMP is added as a solvent for mixing. After stirring for a certain period of time, a uniform positive electrode slurry with a certain fluidity is obtained; the positive electrode slurry is evenly coated on the positive electrode current collector carbon-coated aluminum foil, and then transferred to a 110°C oven for drying, and then rolled, slit, and cut into pieces to obtain a positive electrode sheet.
（2）按质量比96.5:0.5:1.2:1.8将负极活性材料（石墨）、导电剂（导电炭黑SP）、增稠剂（CMC）、粘结剂（SBR）混合制成负极浆料，加入去离子水作为溶剂进行混合，搅拌一定时间后获得具有一定流动性的均匀负极浆料；将负极浆料均匀涂覆在负极集流体铜箔上，随后转移至120℃烘箱进行干燥，然后经过辊压、分条、裁片得到负极极片。(2) The negative electrode active material (graphite), conductive agent (conductive carbon black SP), thickener (CMC), and binder (SBR) are mixed in a mass ratio of 96.5:0.5:1.2:1.8 to prepare a negative electrode slurry, deionized water is added as a solvent for mixing, and after stirring for a certain period of time, a uniform negative electrode slurry with a certain fluidity is obtained; the negative electrode slurry is evenly coated on the negative electrode current collector copper foil, and then transferred to a 120°C oven for drying, and then rolled, slit, and cut into pieces to obtain a negative electrode sheet.
（3）将有机溶剂碳酸乙烯酯、碳酸甲乙酯和碳酸二甲酯按照1：1：1体积比混合。在含水量<10ppm的氩气气氛手套箱中，将干燥充分后的六氟磷酸锂溶解于上述有机溶剂中，浓度为1.1 mol/L混合均匀，获得电解液。(3) Organic solvents ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate were mixed in a volume ratio of 1:1:1. In an argon atmosphere glove box with a water content of <10 ppm, fully dried lithium hexafluorophosphate was dissolved in the above organic solvents to a concentration of 1.1 mol/L and mixed evenly to obtain an electrolyte.
（4）选择16μm在PP材质在带胶隔膜作为隔离膜，将上述的正极极片、隔离膜、负极极片按照顺序叠好，再卷绕成方形的裸电芯后置于铝塑膜中，然后在85℃下烘烤去除水分后，注入一定量的有机电解液后封口，经静置、热冷压、化成、二封、分容等工序后，得到成品二次电池。(4) A 16 μm PP material with adhesive separator is selected as the isolation membrane, and the above-mentioned positive electrode sheet, isolation membrane, and negative electrode sheet are stacked in order, and then wound into a square bare battery cell and placed in an aluminum-plastic film. After baking at 85°C to remove moisture, a certain amount of organic electrolyte is injected and sealed. After standing, hot and cold pressing, formation, secondary sealing, and capacity division, a finished secondary battery is obtained.
实施例6~实施例18：按照实施例5的方法制备实施例6~实施例18，通过调整正极活性材料镍钴锰酸锂中镍、钴、锰比例来控制Q 1，通过负极活性材料的粒径和石墨化度来调节克容量Q 2，通过充电容量的控制来确定Q 3，实施例6~实施例18的参数如表1所示。 Example 6 to Example 18: Example 6 to Example 18 were prepared according to the method of Example 5, and Q 1 was controlled by adjusting the ratio of nickel, cobalt and manganese in the positive electrode active material lithium nickel cobalt manganese oxide, and the gram capacity Q 2 was adjusted by the particle size and graphitization degree of the negative electrode active material. Q 3 was determined by controlling the charging capacity. The parameters of Example 6 to Example 18 are shown in Table 1.
实施例19：按照实施例14的方法制备实施例19，实施例19的参数如表1所示。Example 19: Example 19 was prepared according to the method of Example 14. The parameters of Example 19 are shown in Table 1.
实施例20：按照实施例14的方法制备实施例20，实施例20的参数如表1所示。Example 20: Example 20 was prepared according to the method of Example 14. The parameters of Example 20 are shown in Table 1.
实施例21：按照实施例14的方法制备实施例21，实施例21的参数如表1所示。Example 21: Example 21 was prepared according to the method of Example 14. The parameters of Example 21 are shown in Table 1.
实施例22：按照实施例14的方法制备实施例22，实施例22的参数如表1所示。Example 22: Example 22 was prepared according to the method of Example 14. The parameters of Example 22 are shown in Table 1.
对比例1：按照实施例1的方法制备对比例1，对比例1的参数如表1所示。Comparative Example 1: Comparative Example 1 was prepared according to the method of Example 1. The parameters of Comparative Example 1 are shown in Table 1.
对比例2：按照实施例5的方法制备对比例2，对比例2的参数如表1所示。Comparative Example 2: Comparative Example 2 was prepared according to the method of Example 5. The parameters of Comparative Example 2 are shown in Table 1.
电池的性能测试Battery performance test
容量保持率：二次电池的标称容量为C 1，在一定温度（25℃）条件下1C/1C循环对应的圈数，得到放电容量C 2，容量保持率=C 2/C 1×100%。 Capacity retention rate: The nominal capacity of the secondary battery is C 1 . The discharge capacity C 2 is obtained by the number of cycles corresponding to 1C/1C cycle at a certain temperature (25°C). Capacity retention rate = C 2 /C 1 × 100%.
能量效率：锂离子电池放电时输出的能量与此前充电时输入的能量之比的百分数。Energy efficiency: The percentage of energy output when a lithium-ion battery is discharged compared to the energy input when it was previously charged.
能量效率测试方法：Energy efficiency test method:
二次电池以1C恒流充电至电池的标称容量，记充电能量为E 1； The secondary battery is charged at a constant current of 1C to the nominal capacity of the battery, and the charging energy is recorded as E 1 ;
静置30min；Let stand for 30 minutes;
1C 恒流放电至电压下限（2.5V），记放电能量为E 2； 1C constant current discharge to the voltage lower limit (2.5V), record the discharge energy as E2 ;
二次电池能量效率值为E 2/E 1。 The energy efficiency value of a secondary battery is E 2 /E 1 .
表1 实施例1-22和对比例1-2对应的参数测试结果以及对应制备的二次电池性能测试结果Table 1 Parameter test results corresponding to Examples 1-22 and Comparative Examples 1-2 and performance test results of the corresponding prepared secondary batteries
    Q1 Q1 Q3 Q3 Q2 Q2  (Q1-Q3)/Q3  (Q1-Q3)/Q3 S1 (m2) S1 (m2) S2 (m2) S2 (m2) S1/S2 S1/S2 σ1 σ1 σ2 σ2 (Q2*S2*σ2) /(Q3*S1*σ1) (Q2*S2*σ2) /(Q3*S1*σ1) (Q2*S2*σ2)/ (Q1*S1*σ1) (Q2*S2*σ2)/ (Q1*S1*σ1) 25℃ 1C/1C循环6000圈容量保持率（%） 25℃ 1C/1C cycle 6000 cycles capacity retention rate (%) 25℃ 1C/1C能量效率（%） 25℃ 1C/1C energy efficiency (%)
实施例1 Example 1 130 130 123 123 300 300 0.06 0.06 1.99 1.99 2.0 2.0 0.995 0.995 500 500 224 224 1.10 1.10 1.04 1.04 67.3 67.3 93.4 93.4
实施例2 Example 2 135 135 122 122 305 305 0.11 0.11 1.98 1.98 2.0 2.0 0.99 0.99 480 480 212 212 1.12 1.12 1.01 1.01 69.8 69.8 93.5 93.5
实施例3 Example 3 140 140 121 121 310 310 0.16 0.16 1.97 1.97 2.0 2.0 0.985 0.985 460 460 200 200 1.13 1.13 0.98 0.98 72.6 72.6 93.7 93.7
实施例4 Example 4 145 145 120 120 315 315 0.21 0.21 1.96 1.96 2.0 2.0 0.98 0.98 440 440 188 188 1.14 1.14 0.95 0.95 74.1 74.1 93.8 93.8
实施例5 Example 5 150 150 118 118 320 320 0.27 0.27 1.95 1.95 2.0 2.0 0.975 0.975 420 420 175 175 1.16 1.16 0.91 0.91 76.3 76.3 93.9 93.9
实施例6 Example 6 155 155 117 117 325 325 0.33 0.33 1.94 1.94 2.0 2.0 0.97 0.97 400 400 164 164 1.17 1.17 0.89 0.89 77.2 77.2 94.1 94.1
实施例7 Example 7 160 160 115 115 330 330 0.39 0.39 1.93 1.93 2.0 2.0 0.965 0.965 380 380 152 152 1.19 1.19 0.85 0.85 79.8 79.8 94.2 94.2
实施例8 Example 8 165 165 113 113 335 335 0.45 0.45 1.92 1.92 2.0 2.0 0.96 0.96 360 360 140 140 1.20 1.20 0.82 0.82 81.2 81.2 94.3 94.3
实施例9 Example 9 170 170 114 114 340 340 0.50 0.50 1.91 1.91 2.0 2.0 0.955 0.955 340 340 132 132 1.21 1.21 0.81 0.81 84.5 84.5 94.4 94.4
实施例10 Example 10 175 175 113 113 345 345 0.56 0.56 1.90 1.90 2.0 2.0 0.95 0.95 320 320 121 121 1.22 1.22 0.78 0.78 86.2 86.2 94.4 94.4
实施例11 Example 11 180 180 111 111 350 350 0.62 0.62 1.89 1.89 2.0 2.0 0.945 0.945 300 300 111 111 1.23 1.23 0.76 0.76 89.7 89.7 94.5 94.5
实施例12 Example 12 185 185 110 110 355 355 0.68 0.68 1.88 1.88 2.0 2.0 0.94 0.94 280 280 101 101 1.24 1.24 0.74 0.74 92 92 94.5 94.5
实施例13 Example 13 190 190 109 109 360 360 0.75 0.75 1.87 1.87 2.0 2.0 0.935 0.935 260 260 92 92 1.25 1.25 0.72 0.72 94.2 94.2 94.6 94.6
实施例14 Example 14 195 195 107 107 365 365 0.82 0.82 1.86 1.86 2.0 2.0 0.93 0.93 240 240 82 82 1.25 1.25 0.69 0.69 96.3 96.3 94.7 94.7
实施例15 Example 15 200 200 107 107 370 370 0.87 0.87 1.85 1.85 2.0 2.0 0.925 0.925 220 220 75 75 1.27 1.27 0.68 0.68 98.2 98.2 94.6 94.6
实施例16 Example 16 205 205 107 107 375 375 0.92 0.92 1.84 1.84 2.0 2.0 0.92 0.92 200 200 67 67 1.28 1.28 0.67 0.67 99.1 99.1 94.6 94.6
实施例17 Example 17 210 210 106 106 380 380 0.98 0.98 1.82 1.82 2.0 2.0 0.91 0.91 190 190 62 62 1.29 1.29 0.65 0.65 100 100 94.3 94.3
实施例18 Example 18 215 215 106 106 400 400 1.00 1.00 1.8 1.8 2.01 2.01 0.896 0.896 180 180 56 56 1.31 1.31 0.65 0.65 100 100 94.1 94.1
实施例19 Example 19 195 195 107 107 365 365 0.82 0.82 1.78 1.78 2.0 2.0 0.89 0.89 240 240 82 82 1.31 1.31 0.72 0.72 95.0 95.0 93.2 93.2
实施例20 Example 20 195 195 107 107 365 365 0.82 0.82 2.0 2.0 2.0 2.0 1 1 240 240 82 82 1.17 1.17 0.64 0.64 83.5 83.5 92.9 92.9
实施例21 Example 21 195 195 107 107 365 365 0.82 0.82 1.86 1.86 2.0 2.0 0.93 0.93 510 510 260 260 1.87 1.87 1.03 1.03 59.4 59.4 91.8 91.8
实施例22 Example 22 195 195 107 107 365 365 0.82 0.82 1.86 1.86 2.0 2.0 0.93 0.93 160 160 40 40 0.92 0.92 0.50 0.50 68.7 68.7 92.7 92.7
对比例1 Comparative Example 1 130 130 130 130 300 300 0 0 1.99 1.99 2.0 2.0 0.995 0.995 500 500 233 233 1.08 1.08 1.08 1.08 60.5 60.5 92.0 92.0
对比例2 Comparative Example 2 220 220 104.8 104.8 400 400 1.1 1.1 1.8 1.8 2.0 2.0 0.9 0.9 180 180 56 56 1.32 1.32 0.63 0.63 65.5 65.5 93.1 93.1
由表1的数据可以，与对比例1~2相比，实施例1~实施例18的容量保持率在67%以上，实施例1~实施例18的能量效率在93.4%以上，说明当0＜(Q 1-Q 3)/Q 3≤1.0时，电池的循环寿命和能量效率更优。 From the data in Table 1, compared with Comparative Examples 1-2, the capacity retention rates of Examples 1-18 are above 67%, and the energy efficiencies of Examples 1-18 are above 93.4%, indicating that when 0＜(Q 1 -Q 3 )/Q 3 ≤1.0, the cycle life and energy efficiency of the battery are better.
从实施例1~实施例14可以看出，随着(Q 1-Q 3)/Q 3的增加，能量效率在逐渐增加。主要原因是(Q 1-Q 3)/Q 3增加，正极的脱嵌锂深度变低，脱嵌锂阻力变小，所以能量效率提升。 It can be seen from Examples 1 to 14 that the energy efficiency gradually increases with the increase of (Q 1 -Q 3 )/Q 3. The main reason is that as (Q 1 -Q 3 )/Q 3 increases, the lithium deintercalation depth of the positive electrode becomes lower, and the lithium deintercalation resistance becomes smaller, so the energy efficiency is improved.
从实施例15~实施例18可以看出，随着(Q 1-Q 3)/Q 3的增加，能量效率在减小。主要原因是当(Q 1-Q 3)/Q 3增加到一定比例后，正极的脱嵌锂深度已不是能量效率的决定性因素，二次电池去其他阻抗比重增加，所以能量效率开始下降。 It can be seen from Examples 15 to 18 that the energy efficiency decreases with the increase of (Q 1 -Q 3 )/Q 3. The main reason is that when (Q 1 -Q 3 )/Q 3 increases to a certain ratio, the depth of lithium insertion and extraction of the positive electrode is no longer a decisive factor in the energy efficiency, and the proportion of other impedances of the secondary battery increases, so the energy efficiency begins to decrease.
从实施例1~实施例18可以看出，随着(Q 1-Q 3)/Q 3的增加，电池循环性能在逐渐增加，主要原因是(Q 1-Q 3)/Q 3越大，二次电池正极富余的锂离子越多，可以更多的补偿二次电池循环过程中的活性锂损失，所以电池循环性能增加。 It can be seen from Examples 1 to 18 that as (Q 1 -Q 3 )/Q 3 increases, the battery cycle performance gradually increases. The main reason is that the larger (Q 1 -Q 3 )/Q 3 is, the more surplus lithium ions there are in the secondary battery positive electrode, which can more compensate for the loss of active lithium during the secondary battery cycle, so the battery cycle performance increases.
相较于实施例14，实施例19由于S 1/S 2小于0.9，负极极片富余量过大，造成二次电池充放电过程中因生成SEI而消耗的活性锂增加，所以循环容量保持率和能量效率均变差；实施例20由于S 1/S 2等于1，大于S 1/S 2的范围值，电芯制做过程中负极极片可能无法完全覆盖正极，造成充电过程中负极可能析锂，所以循环容量保持率和能量效率均变差。 Compared with Example 14, in Example 19, since S 1 /S 2 is less than 0.9, the surplus amount of the negative electrode plate is too large, resulting in an increase in the active lithium consumed due to the generation of SEI during the charge and discharge process of the secondary battery, so the cycle capacity retention rate and energy efficiency are both deteriorated; in Example 20, since S 1 /S 2 is equal to 1, which is greater than the range value of S 1 /S 2 , the negative electrode plate may not be able to completely cover the positive electrode during the manufacture of the battery cell, resulting in the possibility of lithium deposition at the negative electrode during the charging process, so the cycle capacity retention rate and energy efficiency are both deteriorated.
相较于实施例14，实施例21由于σ 1和σ 2均大于各自的设计范围，导致正负极极片的动力学变差，影响二次电池工作过程中的锂离子脱嵌，所以循环容量保持率和能量效率均变差；实施例22由于σ 1和σ 2均小于各自的设计范围，导致正负极极片的脱嵌锂速率不平衡，使二次电池在工作过程中的副反应增加，所以循环容量保持率和能量效率均变差。 Compared with Example 14, in Example 21, since σ 1 and σ 2 are both larger than their respective design ranges, the kinetics of the positive and negative electrode sheets deteriorate, affecting the lithium ion deintercalation during the operation of the secondary battery, so the cycle capacity retention rate and the energy efficiency are both deteriorated; in Example 22, since σ 1 and σ 2 are both smaller than their respective design ranges, the lithium deintercalation rates of the positive and negative electrode sheets are unbalanced, which increases the side reactions during the operation of the secondary battery, so the cycle capacity retention rate and the energy efficiency are both deteriorated.
在上述实施例中，对各个实施例的描述都各有侧重，某个实施例中没有详述的部分，可以参见其他实施例的相关描述。In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
以上对本申请实施例所提供的一种二次电池和用电设备进行了详细介绍，本文中应用了具体个例对本申请的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本申请的方法及其核心思想；同时，对于本领域的技术人员，依据本申请的思想，在具体实施方式及应用范围上均会有改变之处，综上所述，本说明书内容不应理解为对本申请的限制。The above is a detailed introduction to a secondary battery and an electrical device provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims (19)

  1. 一种二次电池，其特征在于，包括正极极片，所述正极极片包括正极集流体和设置于所述正极集流体上的正极活性材料层，所述正极活性材料层包括正极活性材料；所述二次电池满足：0＜(Q 1-Q 3)/Q 3≤1.0； A secondary battery, characterized in that it comprises a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, wherein the positive electrode active material layer comprises a positive electrode active material; the secondary battery satisfies: 0＜(Q 1 -Q 3 )/Q 3 ≤1.0;
    其中，Q 1为正极活性材料的最大可逆克容量，单位为mAh/g； Where Q1 is the maximum reversible gram capacity of the positive electrode active material, in mAh/g;
    Q 3为正极活性材料的工作克容量，单位为mAh/g。 Q3 is the working gram capacity of the positive electrode active material, in mAh/g.
  2. 根据权利要求1所述的二次电池，其特征在于，0.05≤(Q 1-Q 3)/Q 3≤0.8。 The secondary battery according to claim 1, wherein 0.05≤(Q 1 -Q 3 )/Q 3 ≤0.8.
  3. 根据权利要求1所述的二次电池，其特征在于，0.1≤(Q 1-Q 3)/Q 3≤0.45。 The secondary battery according to claim 1, wherein 0.1≤(Q 1 -Q 3 )/Q 3 ≤0.45.
  4. 根据权利要求1~3任一项所述的二次电池，其特征在于，所述二次电池还包括负极极片，所述负极极片包括负极集流体和设置于所述负极集流体上的负极活性材料层，所述负极活性材料层包括负极活性材料；所述二次电池满足：The secondary battery according to any one of claims 1 to 3, characterized in that the secondary battery further comprises a negative electrode plate, the negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, the negative electrode active material layer comprises a negative electrode active material; the secondary battery satisfies:
    0.8≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10； 0.8≤(Q 2 *S 2 *σ 2 )/ (Q 1 *S 1 *σ 1 )≤1.10;
    其中，S 2＞S 1； Among them, S 2 >S 1 ;
    S 1为所述正极活性材料层的面积，单位为m 2； S 1 is the area of the positive electrode active material layer, in m 2 ;
    σ 1为所述正极活性材料层的面密度，单位为g/m 2； σ 1 is the surface density of the positive electrode active material layer, in g/m 2 ;
    Q 2为所述负极活性材料的最大可逆克容量，单位为mAh/g； Q2 is the maximum reversible gram capacity of the negative electrode active material, in mAh/g;
    S 2为所述负极活性材料层的面积，单位为m 2； S 2 is the area of the negative electrode active material layer, in m 2 ;
    σ 2为所述负极活性材料层的面密度，单位为g/m 2。 σ 2 is the surface density of the negative electrode active material layer, and its unit is g/m 2 .
  5. 根据权利要求4所述的二次电池，其特征在于，所述二次电池满足：1.1≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.3。 The secondary battery according to claim 4, characterized in that the secondary battery satisfies: 1.1≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.3.
  6. 根据权利要求4所述的二次电池，其特征在于，1.16≤（Q 2*S 2*σ 2）/（Q 3*S 1*σ 1）≤1.25。 The secondary battery according to claim 4, characterized in that 1.16≤(Q 2 *S 2 *σ 2 )/(Q 3 *S 1 *σ 1 )≤1.25.
  7. 根据权利要求4~6任一项所述的二次电池，其特征在于，0.9≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.10。 The secondary battery according to any one of claims 4 to 6, characterized in that 0.9≤(Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 )≤1.10.
  8. 根据权利要求4~6任一项所述的二次电池，其特征在于，1.0≤(Q 2*S 2*σ 2)/ (Q 1*S 1*σ 1)≤1.05。 The secondary battery according to any one of claims 4 to 6, characterized in that 1.0≤(Q 2 *S 2 *σ 2 )/(Q 1 *S 1 *σ 1 )≤1.05.
  9. 根据权利要求4~8任一项所述的二次电池，其特征在于，所述二次电池满足：1.1＜(Q 2*σ 2)/ (Q 3*σ 1)≤1.30。 The secondary battery according to any one of claims 4 to 8, characterized in that the secondary battery satisfies: 1.1＜(Q 2 *σ 2 )/ (Q 3 *σ 1 )≤1.30.
  10. 根据权利要求4~8任一项所述的二次电池，其特征在于，所述二次电池满足：1.14＜(Q 2*σ 2)/ (Q 3*σ 1)≤1.25。 The secondary battery according to any one of claims 4 to 8, characterized in that the secondary battery satisfies: 1.14＜(Q 2 *σ 2 )/ (Q 3 *σ 1 )≤1.25.
  11. 根据权利要求1~10任一项所述的二次电池，其特征在于，所述正极活性材料的最大可逆克容量Q 1满足：130≤Q 1≤215。 The secondary battery according to any one of claims 1 to 10, characterized in that the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 130≤Q 1 ≤215.
  12. 根据权利要求1~10任一项所述的二次电池，其特征在于，所述正极活性材料的工作克容量Q 3满足：65≤Q 3≤200。 The secondary battery according to any one of claims 1 to 10, characterized in that the working gram capacity Q 3 of the positive electrode active material satisfies: 65≤Q 3 ≤200.
  13. 根据权利要求4~12任一项所述的二次电池，其特征在于，所述负极活性材料的最大可逆克容量Q 2满足：300≤Q 2≤400。 The secondary battery according to any one of claims 4 to 12, characterized in that the maximum reversible gram capacity Q 2 of the negative electrode active material satisfies: 300≤Q 2 ≤400.
  14. 根据权利要求1~13任一项所述的二次电池，其特征在于，所述正极活性材料的最大可逆克容量Q 1满足：140≤ Q 1 ≤200。 The secondary battery according to any one of claims 1 to 13, characterized in that the maximum reversible gram capacity Q 1 of the positive electrode active material satisfies: 140≤ Q 1 ≤200.
  15. 根据权利要求4~14任一项所述的二次电池，其特征在于，所述正极活性材料层的面密度σ 1满足：180≤σ 1≤500。 The secondary battery according to any one of claims 4 to 14, characterized in that the surface density σ 1 of the positive electrode active material layer satisfies: 180≤σ 1 ≤500.
  16. 根据权利要求4~14任一项所述的二次电池，其特征在于，所述负极活性材料层的面密度σ 2满足：50≤σ 2≤250。 The secondary battery according to any one of claims 4 to 14, characterized in that the surface density σ 2 of the negative electrode active material layer satisfies: 50≤σ 2 ≤250.
  17. 根据权利要求1~16任一项所述的二次电池，其特征在于，所述正极极片的正极活性材料包括磷酸铁锂、镍钴锰酸锂、镍钴铝酸锂中的一种或多种。The secondary battery according to any one of claims 1 to 16 is characterized in that the positive electrode active material of the positive electrode plate includes one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.
  18. 根据权利要求4~17任一项所述的二次电池，其特征在于，所述负极极片的负极活性材料包括人造石墨、天然石墨、无定型碳、碳纳米管和中间相炭微球中的一种或多种。The secondary battery according to any one of claims 4 to 17 is characterized in that the negative electrode active material of the negative electrode plate comprises one or more of artificial graphite, natural graphite, amorphous carbon, carbon nanotubes and mesophase carbon microspheres.
  19. 用电设备，其特征在于，包括权利要求1~18任一项所述的二次电池。An electrical device, characterized in that it comprises the secondary battery according to any one of claims 1 to 18.
PCT/CN2022/143653 2022-10-27 2022-12-29 Secondary battery and electric device WO2024087382A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211340052.4 2022-10-27
CN202211340052.4A CN115458797A (en) 2022-10-27 2022-10-27 Secondary battery and electric equipment

Publications (1)

Publication Number Publication Date
WO2024087382A1 true WO2024087382A1 (en) 2024-05-02

Family

ID=84310019

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/143653 WO2024087382A1 (en) 2022-10-27 2022-12-29 Secondary battery and electric device

Country Status (2)

Country Link
CN (1) CN115458797A (en)
WO (1) WO2024087382A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118398766A (en) * 2024-06-27 2024-07-26 中国第一汽车股份有限公司 Secondary battery, preparation method thereof and electric equipment

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115458797A (en) * 2022-10-27 2022-12-09 欣旺达电动汽车电池有限公司 Secondary battery and electric equipment
CN115566255B (en) * 2022-10-27 2023-08-15 欣旺达电动汽车电池有限公司 Secondary battery and electric equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101609908A (en) * 2008-06-16 2009-12-23 东莞新能源科技有限公司 A kind of lithium ion battery
CN110212193A (en) * 2018-02-28 2019-09-06 宁德时代新能源科技股份有限公司 Lithium ion secondary battery and method for manufacturing same
CN113097429A (en) * 2021-03-30 2021-07-09 宁德新能源科技有限公司 Electrochemical device and electronic apparatus
CN115458797A (en) * 2022-10-27 2022-12-09 欣旺达电动汽车电池有限公司 Secondary battery and electric equipment

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103187590B (en) * 2011-12-27 2015-05-13 比亚迪股份有限公司 Formation method for lithium ion battery and lithium ion battery
CN103022417A (en) * 2012-12-27 2013-04-03 东莞市安德丰电池有限公司 Anode material of lithium-ion cell
CN106384808B (en) * 2016-11-29 2019-09-06 湖南三迅新能源科技有限公司 A kind of based lithium-ion battery positive plate and preparation method thereof, lithium ion battery
CN108232343B (en) * 2018-01-04 2020-02-14 中南大学 Lithium supplement additive for lithium ion battery, lithium supplement anode, and preparation and application of lithium supplement additive and lithium supplement anode
JP6961103B2 (en) * 2018-09-21 2021-11-05 株式会社東芝 Batteries and battery packs
CN109509909B (en) * 2018-10-17 2020-07-03 宁德时代新能源科技股份有限公司 Secondary battery
CN112201783A (en) * 2020-10-23 2021-01-08 星恒电源股份有限公司 Positive pole piece for lithium ion battery with high cost performance and long cycle life
CN113161510A (en) * 2021-03-22 2021-07-23 欣旺达电动汽车电池有限公司 Electrode pole piece, preparation method thereof and lithium ion battery
CN113224277B (en) * 2021-05-03 2022-04-01 星恒电源股份有限公司 High-safety long-cycle-life positive pole piece for lithium ion battery
CN114566610B (en) * 2022-03-03 2023-09-01 湖北亿纬动力有限公司 Positive electrode with lithium supplementing function and preparation method and application thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101609908A (en) * 2008-06-16 2009-12-23 东莞新能源科技有限公司 A kind of lithium ion battery
CN110212193A (en) * 2018-02-28 2019-09-06 宁德时代新能源科技股份有限公司 Lithium ion secondary battery and method for manufacturing same
CN113097429A (en) * 2021-03-30 2021-07-09 宁德新能源科技有限公司 Electrochemical device and electronic apparatus
CN115458797A (en) * 2022-10-27 2022-12-09 欣旺达电动汽车电池有限公司 Secondary battery and electric equipment

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118398766A (en) * 2024-06-27 2024-07-26 中国第一汽车股份有限公司 Secondary battery, preparation method thereof and electric equipment

Also Published As

Publication number Publication date
CN115458797A (en) 2022-12-09

Similar Documents

Publication Publication Date Title
JP7196364B2 (en) Secondary batteries and battery modules, battery packs and devices containing such secondary batteries
WO2020177623A1 (en) Negative pole piece, secondary battery and apparatus thereof
WO2024087382A1 (en) Secondary battery and electric device
CN110707287B (en) Metal lithium negative electrode, preparation method thereof and lithium battery
WO2024087383A1 (en) Secondary battery and electric device
WO2022057189A1 (en) Solid-state battery, battery module, battery pack, and related device thereof
WO2024016891A1 (en) Pre-lithiated electrode plate and preparation method therefor, secondary battery, and electric device
WO2023070992A1 (en) Electrochemical device and electronic device comprising same
US20240222685A1 (en) Secondary battery and electrical device
WO2024066088A1 (en) Secondary battery and electrical device
CN110212247A (en) Battery cell
WO2024087369A1 (en) Secondary battery and electrical apparatus
WO2023087241A1 (en) Battery group, battery pack, electrical apparatus, manufacturing method and manufacturing device for battery group, and control method for battery group
WO2023029002A1 (en) Negative current collector and secondary battery comprising same, and battery module, battery pack and electric device
CN115275109A (en) Long-cycle lithium iron phosphate thick electrode, preparation method thereof and lithium ion battery
WO2024217031A1 (en) Secondary battery and electric device
WO2024087368A1 (en) Secondary battery and electric device
WO2024087389A1 (en) Secondary battery and electrical device
WO2022161270A1 (en) Lithium ion battery, battery module, battery pack and electricity utilization apparatus
WO2024087390A1 (en) Secondary battery and electrical apparatus
CN112670449B (en) Silicon-carbon composite pole piece, preparation method and application thereof
CN115036458B (en) Lithium ion battery
CN115663118A (en) Positive electrode plate, secondary battery and power utilization device
WO2021128001A1 (en) Secondary battery and device containing same
WO2022174412A1 (en) Electrolyte and electrochemical device comprising same, and electronic device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22963358

Country of ref document: EP

Kind code of ref document: A1