WO2022268147A1 - 一种锂离子电池及其制备方法 - Google Patents

一种锂离子电池及其制备方法 Download PDF

Info

Publication number
WO2022268147A1
WO2022268147A1 PCT/CN2022/100629 CN2022100629W WO2022268147A1 WO 2022268147 A1 WO2022268147 A1 WO 2022268147A1 CN 2022100629 W CN2022100629 W CN 2022100629W WO 2022268147 A1 WO2022268147 A1 WO 2022268147A1
Authority
WO
WIPO (PCT)
Prior art keywords
lithium
negative electrode
positive electrode
ion battery
nickel
Prior art date
Application number
PCT/CN2022/100629
Other languages
English (en)
French (fr)
Inventor
闫晟睿
姜涛
汪龙
刘晓蕾
孙焕丽
赵光宇
翟喜民
Original Assignee
中国第一汽车股份有限公司
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 中国第一汽车股份有限公司 filed Critical 中国第一汽车股份有限公司
Publication of WO2022268147A1 publication Critical patent/WO2022268147A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/61—Types of temperature control
    • H01M10/615—Heating or keeping warm
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/64—Heating or cooling; Temperature control characterised by the shape of the cells
    • H01M10/647—Prismatic or flat cells, e.g. pouch cells
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/654—Means for temperature control structurally associated with the cells located inside the innermost case of the cells, e.g. mandrels, electrodes or electrolytes
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/655—Solid structures for heat exchange or heat conduction
    • H01M10/6551—Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings
    • 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
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/657—Means for temperature control structurally associated with the cells by electric or electromagnetic means
    • H01M10/6571—Resistive heaters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the embodiments of the present application relate to the technical field of lithium-ion batteries, for example, a lithium-ion battery and a preparation method thereof.
  • lithium-ion batteries Due to its outstanding advantages such as high energy density, low self-discharge, and no memory effect, lithium-ion batteries have been widely used in consumer digital products, energy storage power stations, electric bicycles, and electric vehicles. They are new energy sources that replace petroleum in automobiles. plan.
  • lithium-ion batteries due to the relatively complicated environment in which lithium-ion batteries are used, and due to the defects of lithium-ion batteries themselves, the low-temperature performance of current lithium-ion batteries is relatively poor.
  • Existing lithium-ion batteries are used in an environment below -20°C, and discharge will occur. The short time or failure to discharge seriously affects the normal use of the battery, which has limited the promotion and use of lithium-ion battery pure electric vehicles in low-temperature and cold areas.
  • the traditional lithium-ion battery low-temperature solution mainly includes external heating and internal heating of the battery.
  • External heating is mainly achieved through heat conduction or heat convection, and the battery is heated externally through PTC materials or heating films.
  • this method has uneven heating and low heating efficiency, and the cost of the battery system is greatly increased; internal heating directly generates heat inside the battery, so the heating efficiency is higher and the heating is more uniform.
  • due to the low thermal conductivity of the lithium-ion battery structure when the temperature on the surface of the battery rises from -20°C to 0°C, the temperature of the Ni foil in the middle of the battery reaches about 30°C, forming a gap between the inside and the surface of the battery.
  • CN108832181A discloses a kind of preparation technology of lithium-ion low-temperature battery, adds propylene carbonate (PC) in its solution, although PC has better low-temperature performance, but seldom as composition of electrolyte solvent, because PC is easy to be embedded with Li + Graphite negative electrode will lead to the deterioration of the stability of the negative electrode/solution interface, resulting in a decline in battery performance.
  • PC propylene carbonate
  • CN111224102A discloses a kind of preparation method of low-temperature battery, and it adopts polyacrylic acid (PAA) type binder in negative electrode, and electric core adopts winding/stacking process, and the stress at the corner of winding electric core is bigger, and PAA type adhesive
  • PAA polyacrylic acid
  • the junction agent is less flexible and will form fragments when the electrode breaks. The production process is more difficult, and the long-term cycle life is difficult to guarantee.
  • the heat generation of the laminated battery cell is small when it is discharged at low temperature. The retention rate is low.
  • the above solution has the problems of poor cycle performance of the battery, difficult production process or low energy density at low temperature. Therefore, it is very necessary to develop a lithium-ion battery with good cycle performance, simple production process and high energy density at low temperature. .
  • the embodiment of the present application provides a lithium ion battery and its preparation method.
  • polyacrylic acid (PAA) binder is used for the negative electrode
  • nickel-cobalt lithium manganese oxide polycrystalline material and nickel-cobalt lithium manganese oxide single crystal are used for the positive electrode.
  • the material is used as an active material to improve the energy density of the battery at low temperature while improving the cycle performance of the battery.
  • the embodiment of the present application provides a lithium-ion battery
  • the lithium-ion battery includes a positive electrode, a negative electrode and an electrolyte
  • the positive electrode active material in the positive electrode includes nickel-cobalt lithium manganate polycrystalline material and nickel-cobalt-manganese Lithium acid single crystal material
  • the binder in the negative electrode includes polyacrylic acid binder.
  • polyacrylic acid (PAA) binder is used for the negative electrode to improve the low-temperature performance
  • polycrystalline nickel-cobalt-manganese material is used for the positive electrode mixed with single-crystal nickel-cobalt-manganese material to increase the energy density of the battery while increasing the low-temperature DCR of the battery. , increase heat production, and reduce internal polarization of the battery.
  • the lithium-ion battery includes a prismatic cell.
  • current collector blanks are respectively provided on both sides of the square cell.
  • the current collector space is independently provided with resistor sheets and/or foils.
  • the negative electrode adopts polyacrylic acid (PAA) binder, combined with the blank winding method, to improve the heat generation of the battery core at low temperature, and to solve the problem of poor flexibility of the polyacrylic acid binder. Fragments will be formed when broken, and the processing technology is difficult.
  • PAA polyacrylic acid
  • the nickel-cobalt-lithium-manganese-oxide polycrystalline material includes polycrystalline NCM811 material.
  • the single crystal material of nickel cobalt lithium manganese oxide includes any one or a combination of at least two of single crystal NCM523 material, single crystal NCM622 material or single crystal NCM811 material, preferably single crystal NCM523 material, single crystal NCM622 material and a combination of single crystal NCM811 material.
  • the mass ratio of the nickel-cobalt lithium manganese oxide polycrystalline material to the nickel-cobalt lithium manganese oxide single crystal material is (85-90):(10-15), for example: 85:15, 86:14, 87: 13. 88:12 or 90:10 etc.
  • the polyacrylic binder includes any one or a combination of at least two of polymethylacrylate, polyethylacrylate and polyacrylamide.
  • the electrolyte includes a lithium salt and a solvent.
  • the solvent includes any one or a combination of at least two of ethylene carbonate, ethyl methyl carbonate, diethyl carbonate or dimethyl carbonate, preferably ethylene carbonate, ethyl methyl carbonate, diethyl carbonate Combination of ethyl ester and dimethyl carbonate.
  • the volume ratio of the ethylene carbonate, ethyl methyl carbonate, diethyl carbonate or dimethyl carbonate is (4.5 ⁇ 5.5):(1.5 ⁇ 2.5):(1 ⁇ 1.5):(1 ⁇ 1.5) , for example: 4.5:1.5:1:1 or 5:2:1:1.2, 4.8:2.2:1.3:1.3 or 5.2:1.8:1.2:1.2 or 5.5:2.5:1.5:1.5, etc.
  • the lithium salt includes any one or a combination of at least two of LIPF 6 , LIFSI, LiBOB, LiODFB, LiFSI, LiTFSI, LiPO 2 F 2 .
  • the concentration of the lithium salt is 1.0-1.2 mol/L, for example: 1.0 mol/L, 1.05 mol/L, 1.1 mol/L, 1.12 mol/L, 1.15 mol/L or 1.2 mol/L.
  • the embodiment of the present application provides a method for preparing a lithium-ion battery as described in the first aspect, the preparation method comprising the following steps:
  • step (3) After the positive electrode sheet obtained in step (1), the separator, and the negative electrode sheet obtained in step (2) are wound as a whole to obtain an electric core, and the lithium ion battery is obtained after liquid injection;
  • the negative electrode binder includes polyacrylic acid binder.
  • the positive electrode active material in step (1) includes nickel cobalt lithium manganese oxide polycrystalline material and nickel cobalt lithium manganese oxide single crystal material.
  • the conductive paste includes carbon nanotube paste.
  • the positive electrode conductive agent includes carbon black.
  • the positive electrode binder includes polyvinylidene fluoride.
  • the mass ratio of the nickel cobalt lithium manganese oxide polycrystalline material, nickel cobalt lithium manganese oxide single crystal material, carbon nanotube slurry, carbon black and polyvinylidene fluoride is (80 ⁇ 82):(14 ⁇ 16):(0.5 ⁇ 1.5):(0.5 ⁇ 1.5):(1 ⁇ 1.5), for example: 80:14:0.5:0.5:1, 81:15:1:1:1, 82:15:1.2:1 :1.5, 81:15:1.4:1.4:1.2 or 82:16:1.5:1.5:1.5 etc.
  • the positive electrode sheet has a compacted density of 3.3-3.4g/cm 3 , for example: 3.3g/cm 3 , 3.32g/cm 3 , 3.34g/cm 3 , 3.36g/cm 3 , 3.38g/cm 3 , 3.38g/cm 3 , cm 3 or 3.4g/cm 3 etc.
  • the negative electrode active material in step (2) includes graphite.
  • the positive electrode conductive agent includes carbon black.
  • the negative electrode binder further includes sodium carboxymethyl cellulose.
  • the negative electrode additive includes ethylene carbonate and/or propylene carbonate.
  • the mass ratio of graphite, carbon black, sodium carboxymethyl cellulose, polyacrylic acid binder and negative electrode additive is (90 ⁇ 97):(0.6 ⁇ 2.0):(0.2 ⁇ 1.5):(1.5 ⁇ 5):(1 ⁇ 5), for example: 90:0.6:0.2:1.2:2, 92:1:1:2:3, 95:1.2:1.2:1.8:, 95:1.8:0.8:4:4 Or 96:1.8:1.2:3:2 etc.
  • the negative electrode sheet has a compacted density of 1.55-1.65g/cm 3 , for example: 1.55g/cm 3 , 1.58g/cm 3 , 1.6g/cm 3 , 1.62g/cm 3 or 1.65g/cm 3 cm 3 etc.
  • the isolation film in step (3) includes a base film and a ceramic coating coated on at least one side of the base film.
  • the base film includes any one or a combination of at least two of polyolefin films, polyurethane films, aramid films or non-woven fabrics.
  • the ceramic coating includes any one or a combination of at least two of alumina coating, silicon oxide coating, barium sulfate coating or boehmite coating.
  • the porosity of the isolation film is 30-60%, for example: 30%, 35%, 40%, 50% or 60%.
  • the thickness of the isolation film is 12-30 ⁇ m, for example: 12 ⁇ m, 15 ⁇ m, 9 ⁇ m, 25 ⁇ m or 30 ⁇ m.
  • the winding in step (3) includes winding the positive electrode sheet obtained in step (1), the separator, and the negative electrode sheet obtained in step (2) to form a blank winding square battery core. Stack a resistor or foil on each side of the winding space on both sides of the cell.
  • the resistor sheet or foil is located in the middle of the wound square cell.
  • one resistor/foil located in the middle of the winding core is stacked on each side of the winding space on both sides of the battery.
  • the copper foil and aluminum foil in the blank area are heated to uniformly heat up the positive and negative pole pieces as a whole, reduce the low-temperature polarization internal resistance of the battery, and at the same time avoid overheating and aging of local materials of the pole piece, which affects the life of the battery cell.
  • the low temperature performance of the battery and the life of the battery are significantly improved by using the resistor sheet/foil to heat the battery cell in the blank space of the winding.
  • the chemical conversion is performed after the injection in step (3).
  • the formation includes one-step formation, two-step formation and three-step formation.
  • the current of the one-step formation is 0.06-0.1C, for example: 0.06C, 0.07C, 0.08C, 0.09C or 0.1C.
  • the time for the one-step formation is 0.5-1.5 h, for example: 0.5 h, 0.8 h, 1 h, 1.2 h or 1.5 h.
  • the current of the two-step formation is 0.12-0.18C, for example: 0.12C, 0.13C, 0.14C, 0.15C, 0.16C or 0.18C.
  • the time for the two-step formation is 1.5-2.5 hours, for example: 1.5 hours, 1.8 hours, 2 hours, 2.2 hours or 2.5 hours.
  • the current of the three-step formation is 0.24-0.3C, for example: 0.24C, 0.25C, 0.26C, 0.27C, 0.28C, 0.29C or 0.3C.
  • the time for the three-step formation is 0.5-1.5h, for example: 0.5h, 0.8h, 1h, 1.2h or 1.5h.
  • the electric quantity of the battery after formation is 65-75% SOC, for example: 65% SOC, 68% SOC, 70% SOC, 72% SOC or 75% SOC and so on.
  • aging, liquid replenishment, sealing and volume separation are performed after the formation.
  • the aging time is 24-120h, for example: 24h, 48h, 60h, 90h, 100h or 120h and so on.
  • polyacrylic acid (PAA) binder is used for the negative electrode to improve the low-temperature performance
  • polycrystalline nickel-cobalt-manganese material is used for the positive electrode mixed with single-crystal nickel-cobalt-manganese material to increase the energy density of the battery while increasing the Low-temperature DCR of the battery increases heat production and reduces internal polarization of the battery.
  • PAA polyacrylic acid
  • polycrystalline nickel-cobalt-manganese material is used for the positive electrode mixed with single-crystal nickel-cobalt-manganese material to increase the energy density of the battery while increasing the Low-temperature DCR of the battery increases heat production and reduces internal polarization of the battery.
  • PAA polyacrylic acid
  • nickel-cobalt-manganese material is used for the positive electrode mixed with single-crystal nickel-cobalt-manganese material to increase the energy density of the battery while increasing the Low-temperature DCR of the battery increases heat production and reduce
  • one resistor/foil located in the middle of the core is stacked on each side of the winding blank on both sides of the cell.
  • the resistor/foil Heat the copper foil and aluminum foil on the blank part of the winding core to uniformly heat up the positive and negative pole pieces as a whole, reduce the low-temperature polarization internal resistance of the battery, and at the same time avoid overheating and aging of the partial material of the pole piece, which will affect the life of the battery cell.
  • the low temperature performance of the battery and the life of the battery are significantly improved by using the resistor sheet/foil to heat the battery cell in the blank space of the winding.
  • FIG. 1 is a schematic diagram of the preparation process of the lithium-ion battery described in Example 1 of the present application.
  • Figure 2 is a schematic structural view of the positive pole piece and the negative pole piece described in Example 1 of the present application before winding, 1-positive current collector, 2-negative current collector, 3-slurry coating area, 4-coating blank area.
  • This embodiment provides a kind of lithium ion battery, and described lithium ion battery is made by following method:
  • the polycrystalline material of nickel cobalt lithium manganate is polycrystalline NCM811 material
  • the single crystal material of nickel cobalt lithium manganate is single crystal NCM523 material, single crystal NCM622 material and single crystal NCM811 material
  • the polycrystalline NCM811 material single crystal
  • the mass ratio of NCM523 material, single crystal NCM622 material and single crystal NCM811 material is 88:5:4:3;
  • the isolation film is a polyurethane film with aluminum oxide coating on both sides, a porosity of 40%, and a thickness of 9 ⁇ m;
  • the formation process is 0.08C, charging for 1h, charging at 0.185C, charging for 2h, charging at 0.25C, charging for 1h, charging to 70% SOC, aging at room temperature at 25°C for 72h, and aging at high temperature at 45°C for 12h.
  • FIG. 1 The schematic diagram of the preparation process of the lithium-ion battery is shown in FIG. 1 .
  • FIG. 1 The structure schematic diagram of the positive pole piece and the negative pole piece before winding is shown in Figure 2, 1-positive current collector, 2-negative current collector, 3-slurry coating area, 4-coating blank area.
  • This embodiment provides a kind of lithium ion battery, and described lithium ion battery is made by following method:
  • the polycrystalline material of nickel cobalt lithium manganate is polycrystalline NCM811 material
  • the single crystal material of nickel cobalt lithium manganate is single crystal NCM523 material, single crystal NCM622 material and single crystal NCM811 material
  • the polycrystalline NCM811 material single crystal
  • the mass ratio of NCM523 material, single crystal NCM622 material and single crystal NCM811 material is 89:4:4:3;
  • the isolation film is a polyurethane film with aluminum oxide coating on both sides, a porosity of 40%, and a thickness of 9 ⁇ m;
  • the formation process is 0.08C, charging for 1h, charging at 0.185C, charging for 2h, charging at 0.25C, charging for 1h, charging to 70% SOC, aging at room temperature at 25°C for 72h, and aging at high temperature at 45°C for 12h.
  • Example 1 The only difference between this example and Example 1 is that the amount of polymethyl acrylate added is 1.5 parts by mass, and other conditions and parameters are exactly the same as those of Example 1.
  • Example 1 The only difference between this example and Example 1 is that the amount of polymethyl acrylate added is 5 parts by mass, and other conditions and parameters are exactly the same as those of Example 1.
  • Example 1 The only difference between this example and Example 1 is that the mass ratio of nickel-cobalt lithium manganese oxide polycrystalline material to nickel-cobalt lithium manganese oxide single crystal material is 80:20, and other conditions and parameters are exactly the same as those in Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that the positive electrode only uses polycrystalline NCM811 material as the active material, and other conditions and parameters are exactly the same as those of Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that the positive electrode only uses single crystal NCM811 material as the active material, and other conditions and parameters are exactly the same as those of Example 1.
  • Example 1 The only difference between this comparative example and Example 1 is that all the polymethyl acrylate added to the negative electrode is replaced by carboxymethyl cellulose sodium (that is, no polyacrylic acid binder is added), and other conditions and parameters are exactly the same as in Example 1. .
  • the low-temperature charge capacity of the lithium-ion battery described in the present application can reach more than 166mAh/g
  • the low-temperature discharge capacity can reach more than 146mAh/g
  • the energy density can reach 232Wh/g.
  • the capacity retention rate can reach more than 75% after 500 cycles.
  • Example 1 From the comparison of Example 1 and Examples 3-4, it can be seen that the addition amount of polyacrylic acid binder will affect the performance of the lithium-ion battery, so the addition amount of polyacrylic acid binder is controlled at 1.5 to 5 parts by mass , Lithium-ion batteries with better performance will be produced. If the amount of polyacrylic acid binder added is too small, the surface coating of lithium-ion battery pole pieces may fall off, and at the same time increase the difficulty of manufacturing battery pole pieces. If too much polyacrylic acid binder is added, the energy density of the lithium-ion battery will be reduced.
  • Example 1 From the comparison of Example 1 and Examples 5-6, it can be seen that in the positive electrode active material, the mass ratio of the nickel-cobalt lithium manganese oxide polycrystalline material and the nickel-cobalt lithium manganese oxide single crystal material will affect the performance of the lithium-ion battery.
  • the mass ratio of nickel cobalt lithium manganese oxide polycrystalline material and nickel cobalt lithium manganese oxide single crystal material is controlled at (85 ⁇ 90):(10:15) will produce a lithium-ion battery with excellent performance. If the proportion of crystalline materials is too large, the DCR of the lithium-ion battery will decrease, the heat production of the battery will decrease at low temperature, and the polarization of the battery will increase at low temperature, which will affect the low-temperature energy density of the lithium-ion battery. If the single crystal material of nickel cobalt lithium manganese oxide accounts for too much, it will increase the DCR of the battery and reduce the energy density of the lithium ion battery.
  • Example 7 From the comparison of Example 1 and Example 7, it can be seen that the present application adopts multi-step and gradually increasing current for chemical formation to form a loose, porous and stable SEI film, which can reduce impedance.
  • Example 1 From the comparison of Example 1 and Comparative Example 1-2, it can be obtained that the present application uses polycrystalline nickel-cobalt-manganese materials mixed with single-crystal nickel-cobalt-manganese materials in the positive electrode, while increasing the energy density of the battery, it increases the low-temperature DCR of the battery and increases the heat output , reduce the internal polarization of the battery.
  • Example 1 Comparative Example 3
  • PAA polyacrylic acid
  • the binder has poor flexibility, and fragments will be formed when the electrodes are broken in the wound battery core, which is a problem that the processing technology is difficult.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

一种锂离子电池及其制备方法，锂离子电池包括正极、负极和电解液，正极中的正极活性物质包括镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料，负极中的粘结剂包括聚丙烯酸类粘结剂，在改善电池循环性能的同时提高低温下电池的能量密度。

Description

一种锂离子电池及其制备方法 技术领域
本申请实施例涉及锂离子电池技术领域，例如一种锂离子电池及其制备方法。
背景技术
锂离子电池由于具有能量密度高，自放电低，无记忆效应等突出优点，已经广泛应用于消费类数码产品、储能电站、电动自行车以及电动汽车等领域，是代替石油用在汽车的新能源方案。但是由于锂离子电池的使用环境相对复杂，并且由于锂离子电池自身存在缺陷，目前的锂离子电池低温性能相对较差，现有的锂离子电池在-20℃以下的环境下使用，会出现放电时间短或无法放电等情况，严重影响电池的正常使用，已经限制了锂离子电池纯电动汽车在低温高寒区域的推广使用。
相关技术中，传统锂离子电池低温解决方案，主要为电池外部加热和内部加热。外部加热主要是通过热传导或热对流的途径实现，通过PTC材料或加热膜等在外部对电池进行加热。但该方式受热不均匀且加热效率较低，而且电池系统地成本大幅增加；内部加热直接在电池内部产生热量，故其加热效率更高，受热更加均匀。但由于锂离子电池结构的导热系数较低，当电池表面的温度从-20℃升到0℃时，位于电池中间Ni箔的温度达到了30℃左右，在电池内部与表面之间形成了很大的温度梯度，这一温度差异会导致不同电池极片放电倍率的差异。自加热过程由于较大的温度梯度的存在对电池的性能产生了不良的影响，同时也导致锂电池的加热能耗较大。
传统低温电池主要通过添加低熔点、低温下粘度低的电解液溶剂方式为主，在低温性能提升的同时，严重削弱了电池的常温性能，且长期低温循环性能也 难以保证，应用领域较为局限。
CN108832181A公开了一种锂离子低温电池的制备工艺，其溶液中加入碳酸丙烯酯(PC)，PC虽具有较好的低温性能，但很少作为电解液溶剂组成，因PC易与Li +共嵌入石墨负极，会导致负极电极/溶液界面稳定性变差，造成电池性能的下降，阻抗随环境的改变变化幅度较大，电池的循环性能和倍率性能也会下降，含有PC的电池高倍率放电平台也会降低。
CN111224102A公开了一种低温电池的制备方法，其在负极采用聚丙烯酸(PAA)类粘结剂，电芯采用卷绕/叠片工艺，卷绕电芯拐角处所受应力较大，PAA类粘结剂柔性较差，在电极破裂时会形成碎片，生产工艺难度较大，且长期循环寿命难以保证，而叠片电芯低温放电时产热较小，低温时，电池极化过大导致容量保持率偏低。
上述方案存在有电池的循环性能差、生产工艺难度大或低温下能量密度低的问题，因此，开发一种循环性能好，生产工艺简单且在低温下能量密度高的锂离子电池是十分必要的。
发明内容
以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本申请实施例提供一种锂离子电池及其制备方法，本申请实施例通过负极采用聚丙烯酸(PAA)类粘结剂，正极采用镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料作为活性物质，在改善电池循环性能的同时提高低温下电池的能量密度。
第一方面，本申请实施例提供了一种锂离子电池，所述锂离子电池包括正极、负极和电解液，所述正极中的正极活性物质包括镍钴锰酸锂多晶材料和镍 钴锰酸锂单晶材料，所述负极中的粘结剂包括聚丙烯酸类粘结剂。
本申请实施例通过负极采用聚丙烯酸(PAA)类粘结剂，改善低温性能，正极采用多晶镍钴锰材料混合单晶镍钴锰材料，在提高电池能量密度的同时，增大电池低温DCR，提高产热量，降低电池内部极化现象。在不使用低温电解液的前提下，可以在-40℃的低温环境下使用，在-30℃环境下0.5C放电容量达到了电池初始容量的80％以上，同时提高了低温电池的能量密度，低温性能优异。
优选地，所述锂离子电池包括方形电芯。
优选地，所述方形电芯两侧分别设置有集流体留白。
优选地，所述集流体留白独立地设置有电阻片和/或箔片。
本申请实施例中负极采用聚丙烯酸(PAA)类粘结剂，结合留白卷绕方式，提升电芯低温时产热，并解决聚丙烯酸类粘结剂柔性较差，在卷绕电芯中电极破裂时会形成碎片，加工工艺难度较大的问题。
优选地，所述镍钴锰酸锂多晶材料包括多晶NCM811材料。
优选地，所述镍钴锰酸锂单晶材料包括单晶NCM523材料、单晶NCM622材料或单晶NCM811材料中的任意一种或至少两种的组合，优选为单晶NCM523材料、单晶NCM622材料和单晶NCM811材料的组合。
优选地，所述镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比为(85～90):(10～15)，例如：85:15、86:14、87:13、88:12或90:10等。
优选地，所述聚丙烯酸类粘结剂包括聚丙烯酸甲酯、聚丙烯酸乙酯和聚丙烯酰胺中的任意一种或至少两种的组合。
优选地，所述电解液包括锂盐和溶剂。
优选地，所述溶剂包括碳酸乙烯酯、碳酸甲乙酯、碳酸二乙酯或碳酸二甲酯中的任意一种或至少两种的组合，优选为碳酸乙烯酯、碳酸甲乙酯、碳酸二 乙酯和碳酸二甲酯的组合。
优选地，所述碳酸乙烯酯、碳酸甲乙酯、碳酸二乙酯或碳酸二甲酯的体积比为(4.5～5.5):(1.5～2.5):(1～1.5):(1～1.5)，例如：4.5:1.5:1:1或5:2:1:1.2、4.8:2.2:1.3:1.3或5.2:1.8:1.2:1.2或5.5:2.5:1.5:1.5等。
优选地，所述锂盐包括LIPF 6、LIFSI、LiBOB、LiODFB、LiFSI、LiTFSI、LiPO 2F 2中的任意一种或至少两种的组合。
优选地，所述锂盐的浓度为1.0～1.2mol/L，例如：1.0mol/L、1.05mol/L、1.1mol/L、1.12mol/L、1.15mol/L或1.2mol/L等。
第二方面，本申请实施例提供了一种如第一方面所述锂离子电池的制备方法，所述制备方法包括以下步骤：
(1)将正极活性物质、导电浆料、正极导电剂、正极粘结剂和溶剂混合得到正极浆料，将正极浆料间歇涂覆在正极集流体表面，得到正极极片；
(2)将负极活性物质、负极导电剂、负极粘结剂、负极添加剂和溶剂混合得到负极浆料，将负极浆料间歇涂覆在负极集流体表面，得到负极极片；
(3)将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后得到电芯，注液后得到所述锂离子电池；
其中，所述负极粘结剂包括聚丙烯酸类粘结剂。
优选地，步骤(1)所述正极活性物质包括镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料。
优选地，所述导电浆料包括碳纳米管浆料。
优选地，所述正极导电剂包括炭黑。
优选地，所述正极粘结剂包括聚偏二氟乙烯。
优选地，所述镍钴锰酸锂多晶材料、镍钴锰酸锂单晶材料、碳纳米管浆料、 炭黑和聚偏二氟乙烯的质量比为(80～82):(14～16):(0.5～1.5):(0.5～1.5):(1～1.5)，例如：80:14:0.5:0.5:1、81:15:1:1:1、82:15:1.2:1:1.5、81:15:1.4:1.4:1.2或82:16:1.5:1.5:1.5等。
优选地，所述正极极片的压实密度为3.3～3.4g/cm 3，例如：3.3g/cm 3、3.32g/cm 3、3.34g/cm 3、3.36g/cm 3、3.38g/cm 3或3.4g/cm 3等。
优选地，步骤(2)所述负极活性物质包括石墨。
优选地，所述正极导电剂包括炭黑。
优选地，所述负极粘结剂还包括羧甲基纤维素纳。
优选地，所述负极添加剂包括碳酸乙烯酯和/或碳酸丙烯酯。
优选地，所述石墨、碳黑、羧甲基纤维素纳、聚丙烯酸类粘结剂和负极添加剂的质量比为(90～97):(0.6～2.0):(0.2～1.5):(1.5～5):(1～5)，例如：90：0.6：0.2：1.2：2、92:1:1:2:3、95:1.2:1.2:1.8:、95:1.8:0.8:4:4或96:1.8:1.2:3:2等。
优选地，所述负极极片的压实密度为1.55～1.65g/cm 3，例如：1.55g/cm 3、1.58g/cm 3、1.6g/cm 3、1.62g/cm 3或1.65g/cm 3等。
优选地，步骤(3)所述隔离膜包括基膜和涂覆在基膜至少一面上的陶瓷涂层。
优选地，所述基膜包括聚烯烃膜、聚氨酯膜、芳纶膜或无纺布中的任意一种或至少两种的组合。
优选地，所述陶瓷涂层包括氧化铝涂层、氧化硅涂层、硫酸钡涂层或勃姆石涂层中的任意一种或至少两种的组合。
优选地，所述隔离膜的孔隙率为30～60％，例如：30％、35％、40％、50％或60％等。
优选地，所述隔离膜的厚度为12～30μm，例如：12μm、15μm、9μm、25μm 或30μm等。
优选地，步骤(3)所述卷绕包括将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后形成留白卷绕的方形电芯，在电芯两侧的卷绕留白处，各堆叠一个电阻片或箔片。
优选地，所述电阻片或箔片位于所述卷绕的方形电芯中部。
本申请实施例通过在电芯两侧的卷绕留白处，各堆叠一个位于卷芯中部的电阻片/箔片，当电芯温度低于0℃时，通过电阻片/箔片对卷芯留白处铜箔、铝箔进行加热，使正负极极片整体均匀升温，降低电池低温极化内阻，同时避免极片局部材料过热老化，影响电芯寿命。通过在卷绕留白处使用电阻片/箔片对电芯进行加热，使电芯低温性能及电芯寿命明显提高。
优选地，步骤(3)所述注液后进行化成。
优选地，所述化成包括一步化成、二步化成和三步化成。
优选地，所述一步化成的电流为0.06～0.1C，例如：0.06C、0.07C、0.08C、0.09C或0.1C等。
优选地，所述一步化成的时间为0.5～1.5h，例如：0.5h、0.8h、1h、1.2h或1.5h等。
优选地，所述二步化成的电流为0.12～0.18C，例如：0.12C、0.13C、0.14C、0.15C、0.16C或0.18C等。
优选地，所述二步化成的时间为1.5～2.5h，例如：1.5h、1.8h、2h、2.2h或2.5h等。
优选地，所述三步化成的电流为0.24～0.3C，例如：0.24C、0.25C、0.26C、0.27C、0.28C、0.29C或0.3C等。
优选地，所述三步化成的时间为0.5～1.5h，例如：0.5h、0.8h、1h、1.2h或 1.5h等。
优选地，所述化成后电池的电量为65～75％SOC，例如：65％SOC、68％SOC、70％SOC、72％SOC或75％SOC等。
本申请实施例通过优化化成工艺，采用多步逐渐增大的电流进行化成，形成疏松多孔状稳定的SEI膜，降低阻抗。
优选地，所述化成后进行老化、补液、封口及分容。
优选地，所述老化的时间为24～120h，例如：24h、48h、60h、90h、100h或120h等。
相对于相关技术，本申请具有以下有益效果：
(1)本申请实施例通过负极采用聚丙烯酸(PAA)类粘结剂，改善低温性能，正极采用多晶镍钴锰材料混合单晶镍钴锰材料，在提高电池能量密度的同时，增大电池低温DCR，提高产热量，降低电池内部极化现象。在不使用低温电解液的前提下，可以在-40℃的低温环境下使用，在-30℃环境下0.5C放电容量达到了电池初始容量的80％以上，同时提高了低温电池的能量密度，低温性能特别优异。
(2)本申请实施例通过在电芯两侧的卷绕留白处，各堆叠一个位于卷芯中部的电阻片/箔片，当电芯温度低于0℃时，通过电阻片/箔片对卷芯留白处铜箔、铝箔进行加热，使正负极极片整体均匀升温，降低电池低温极化内阻，同时避免极片局部材料过热老化，影响电芯寿命。通过在卷绕留白处使用电阻片/箔片对电芯进行加热，使电芯低温性能及电芯寿命明显提高。
在阅读并理解了附图和详细描述后，可以明白其他方面。
附图说明
附图用来提供对本文技术方案的进一步理解，并且构成说明书的一部分，与本申请的实施例一起用于解释本文的技术方案，并不构成对本文技术方案的限制。
图1是本申请实施例1所述锂离子电池的制备过程示意图。
图2是本申请实施例1所述正极极片和负极极片卷绕前的结构示意图，1-正极集流体，2-负极集流体，3-浆料涂覆区域，4-涂覆留白区域。
具体实施方式
下面通过具体实施方式来进一步说明本申请的技术方案。本领域技术人员应该明了，所述实施例仅仅是帮助理解本申请，不应视为对本申请的具体限制。
实施例1
本实施例提供了一种锂离子电池，所述锂离子电池通过如下方法制得：
(1)将镍钴锰酸锂多晶材料、镍钴锰酸锂单晶材料、碳纳米管浆料、炭黑和聚偏二氟乙烯按照质量比为82:15:0.5:1.0:1.5混合后加入氮甲基吡咯烷酮搅拌得到正极浆料，将所述正极浆料间歇涂覆在铝箔上面，通过辊压，分切、模切得到压实密度为3.35g/cm 3的正极极片；
其中镍钴锰酸锂多晶材料为多晶NCM811材料，所述镍钴锰酸锂单晶材料为单晶NCM523材料、单晶NCM622材料和单晶NCM811材料，所述多晶NCM811材料、单晶NCM523材料、单晶NCM622材料和单晶NCM811材料的质量比为88:5:4:3；
(2)将石墨、碳黑、羧甲基纤维素纳、聚丙烯酸甲酯和碳酸乙烯酯按照质量比为95.5:0.8:1.2:3:1混合加入水中搅拌得到负极浆料，将所述负极浆料间歇涂覆在铜箔上面，通过辊压，分切、模切得到压实密度为1.60g/cm 3的负极极片；
(3)将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后形成留白卷绕的方形电芯，在电芯两侧的卷绕留白处，各堆叠一个电阻片，位于卷芯中部，通过控制电极片长度方向上的留白宽度，使正极片和负极片在长度方向上的留白位于电芯弯曲后的最大曲率处，并且位于电芯弯曲后最大曲率处的正极片的留白宽度大于负极片的留白宽度卷芯热压后，将正负极极耳分别与正负极转接片焊接，将卷芯放入方形铝电池壳中，激光焊接完成封装，烘烤后的卷芯注入电解液，高温静置，经化成、老化、补液、封口及分容后得到所述锂离子电池；
其中，所述隔离膜为两面涂覆有氧化铝涂层，孔隙率为40％，厚度为9μm的聚氨酯膜；
所述电解液的溶剂体积比例为EC：EMC：DEC：DMC＝5:2:1.5:1.5，电解质采用LIPF 6，浓度为1.0mol/L；
化成工艺流程为0.08C，充电1h，0.185C，充电2h，0.25C，充电1h，充电至70％SOC，25℃常温老化72h，45℃高温老化12h。
所述锂离子电池的制备过程示意图如图1所示。
所述正极极片和负极极片卷绕前的结构示意图如图2所示，1-正极集流体，2-负极集流体，3-浆料涂覆区域，4-涂覆留白区域。
实施例2
本实施例提供了一种锂离子电池，所述锂离子电池通过如下方法制得：
(1)将镍钴锰酸锂多晶材料、镍钴锰酸锂单晶材料、碳纳米管浆料、炭黑和聚偏二氟乙烯按照质量比为81:16:0.5:1.0:1.5混合后加入氮甲基吡咯烷酮搅拌得到正极浆料，将所述正极浆料间歇涂覆在铝箔上面，通过辊压，分切、模切 得到压实密度为3.3g/cm 3的正极极片；
其中镍钴锰酸锂多晶材料为多晶NCM811材料，所述镍钴锰酸锂单晶材料为单晶NCM523材料、单晶NCM622材料和单晶NCM811材料，所述多晶NCM811材料、单晶NCM523材料、单晶NCM622材料和单晶NCM811材料的质量比为89:4:4:3；
(2)将石墨、碳黑、羧甲基纤维素纳、聚丙烯酸乙酯和碳酸乙烯酯按照质量比为95:0.8:1.2:1.8:1.2混合加入水中搅拌得到负极浆料，将所述负极浆料间歇涂覆在铜箔上面，通过辊压，分切、模切得到压实密度为1.58g/cm 3的负极极片；
(3)将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后形成留白卷绕的方形电芯，在电芯两侧的卷绕留白处，各堆叠一个电阻片，位于卷芯中部，通过控制电极片长度方向上的留白宽度，使正极片和负极片在长度方向上的留白位于电芯弯曲后的最大曲率处，并且位于电芯弯曲后最大曲率处的正极片的留白宽度大于负极片的留白宽度卷芯热压后，将正负极极耳分别与正负极转接片焊接，将卷芯放入方形铝电池壳中，激光焊接完成封装，烘烤后的卷芯注入电解液，高温静置，经化成、老化、补液、封口及分容后得到所述锂离子电池；
其中，所述隔离膜为两面涂覆有氧化铝涂层，孔隙率为40％，厚度为9μm的聚氨酯膜；
所述电解液的溶剂体积比例为EC：EMC：DEC：DMC＝5:2:2:1，电解质采用LIPF 6，浓度为1.1mol/L；
化成工艺流程为0.08C，充电1h，0.185C，充电2h，0.25C，充电1h，充电至70％SOC，25℃常温老化72h，45℃高温老化12h。
实施例3
本实施例与实施例1区别仅在于，聚丙烯酸甲酯的添加量为1.5质量份，其他条件与参数与实施例1完全相同。
实施例4
本实施例与实施例1区别仅在于，聚丙烯酸甲酯的添加量为5质量份，其他条件与参数与实施例1完全相同。
实施例5
本实施例与实施例1区别仅在于，镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比为80:20，其他条件与参数与实施例1完全相同。
实施例6
本实施例与实施例1区别仅在于，镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比为95:5，其他条件与参数与实施例1完全相同。
实施例7
本实施例与实施例1区别仅在于，化成工艺流程为一步化成，0.185C充电4h，其他条件与参数与实施例1完全相同。
对比例1
本对比例与实施例1区别仅在于，正极仅采用多晶NCM811材料作为活性物质，其他条件与参数与实施例1完全相同。
对比例2
本对比例与实施例1区别仅在于，正极仅采用单晶NCM811材料作为活性物质，其他条件与参数与实施例1完全相同。
对比例3
本对比例与实施例1区别仅在于，将负极加入的聚丙烯酸甲酯全部换为羧甲基纤维素纳(即不加入聚丙烯酸类粘结剂)，其他条件与参数与实施例1完全相同。
性能测试：
取实施例1-7和对比例1-3得到的电池，在-30℃进行充放电容量测试，在常温下测试能量密度，并进行0.5C/1C充放电循环测试，测试结果如表1所示：
表1
Figure PCTCN2022100629-appb-000001
由表1可以看出，由实施例1-7可得，本申请所述锂离子电池的低温充电容 量可达166mAh/g以上，低温放电容量可达146mAh/g以上，能量密度可达232Wh/kg以上，循环500周容量保持率可达75％以上。
由实施例1和实施例3-4对比可得，聚丙烯酸类粘结剂的添加量会影响制得锂离子电池的性能，将聚丙烯酸类粘结剂的添加量控制在1.5～5质量份，会制得性能较好的锂离子电池，若聚丙烯酸类粘结剂的添加量过少，锂离子电池极片表面涂层可能会产生脱落，同时增加电池极片生产制造难度。若聚丙烯酸类粘结剂的添加量过多，会降低锂离子电池的能量密度。
由实施例1和实施例5-6对比可得，正极活性物质中，镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比会影响制得锂离子电池的性能，将镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比控制在(85～90):(10:15)会制得性能优异的锂离子电池，若镍钴锰酸锂多晶材料占比过多，锂离子电池DCR会降低，电池低温时的产热量会减少，低温时电池的极化增大，进而影响锂离子电池低温能量密度。若镍钴锰酸锂单晶材料占比过多，会增大电池的DCR，并且降低锂离子电池的能量密度。
由实施例1和实施例7对比可得，本申请采用多步逐渐增大的电流进行化成，形成疏松多孔状稳定的SEI膜，可以降低阻抗。
由实施例1和对比例1-2对比可得，本申请在正极采用多晶镍钴锰材料混合单晶镍钴锰材料，在提高电池能量密度的同时，增大电池低温DCR，提高产热量，降低电池内部极化现象。
由实施例1和对比例3对比可得，本申请通过负极采用聚丙烯酸(PAA)类粘结剂，改善低温性能，结合留白卷绕方式，提升电芯低温时产热，并解决聚丙烯酸类粘结剂柔性较差，在卷绕电芯中电极破裂时会形成碎片，加工工艺难 度较大的问题。
申请人声明，以上所述仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，所属技术领域的技术人员应该明了，任何属于本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到的变化或替换，均落在本申请的保护范围和公开范围之内。

Claims (15)

  1. 一种锂离子电池，其中，所述锂离子电池包括正极、负极和电解液，所述正极中的正极活性物质包括镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料，所述负极中的粘结剂包括聚丙烯酸类粘结剂。
  2. 如权利要求1所述的锂离子电池，其中，所述锂离子电池包括方形电芯。
  3. 如权利要求2所述的锂离子电池，其中，所述方形电芯两侧分别设置有集流体留白。
  4. 如权利要求3所述的锂离子电池，其中，所述集流体留白独立地设置有电阻片和/或箔片。
  5. 如权利要求1-4任一项所述的锂离子电池，其特征在于所述镍钴锰酸锂多晶材料包括多晶NCM811材料；
    优选地，所述镍钴锰酸锂单晶材料包括单晶NCM523材料、单晶NCM622材料或单晶NCM811材料中的任意一种或至少两种的组合，优选为单晶NCM523材料、单晶NCM622材料和单晶NCM811材料的组合；
    优选地，所述镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料的质量比为(85～90):(10～15)；
    优选地，所述聚丙烯酸类粘结剂包括聚丙烯酸甲酯、聚丙烯酸乙酯和聚丙烯酰胺中的任意一种或至少两种的组合。
  6. 如权利要求1-5任一项所述的锂离子电池，其特征在于，所述电解液包括锂盐和溶剂；
    优选地，所述溶剂包括碳酸乙烯酯、碳酸甲乙酯、碳酸二乙酯或碳酸二甲酯中的任意一种或至少两种的组合，优选为碳酸乙烯酯、碳酸甲乙酯、碳酸二乙酯和碳酸二甲酯的组合；
    优选地，所述碳酸乙烯酯、碳酸甲乙酯、碳酸二乙酯或碳酸二甲酯的体积 比为(4.5～5.5):(1.5～2.5):(1～1.5):(1～1.5)；
    优选地，所述锂盐包括LIPF 6、LIFSI、LiBOB、LiODFB、LiFSI、LiTFSI、LiPO 2F 2中的任意一种或至少两种的组合；
    优选地，所述锂盐的浓度为1.0～1.2mol/L。
  7. 一种如权利要求1-6任一项所述锂离子电池的制备方法，其包括以下步骤：
    (1)将正极活性物质、导电浆料、正极导电剂、正极粘结剂和溶剂混合得到正极浆料，将正极浆料间歇涂覆在正极集流体表面，得到正极极片；
    (2)将负极活性物质、负极导电剂、负极粘结剂、负极添加剂和溶剂混合得到负极浆料，将负极浆料间歇涂覆在负极集流体表面，得到负极极片；
    (3)将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后得到电芯，注液后得到所述锂离子电池；
    其中，所述负极粘结剂包括聚丙烯酸类粘结剂。
  8. 如权利要求7所述的制备方法，其中，步骤(1)所述正极活性物质包括镍钴锰酸锂多晶材料和镍钴锰酸锂单晶材料。
  9. 如权利要求7所述的制备方法，其中，所述导电浆料包括碳纳米管浆料。
  10. 如权利要求7所述的制备方法，其中，所述正极导电剂包括炭黑。
  11. 如权利要求7所述的制备方法，其中，所述正极粘结剂包括聚偏二氟乙烯；
    优选地，所述镍钴锰酸锂多晶材料、镍钴锰酸锂单晶材料、碳纳米管浆料、炭黑和聚偏二氟乙烯的质量比为(80～82):(14～16):(0.5～1.5):(0.5～1.5):(1～1.5)；
    优选地，所述正极极片的压实密度为3.3～3.4g/cm 3。
  12. 如权利要求7-11所述的制备方法，其中，步骤(2)所述负极活性物质 包括石墨；
    优选地，所述正极导电剂包括炭黑；
    优选地，所述负极粘结剂还包括羧甲基纤维素纳；
    优选地，所述负极添加剂包括碳酸乙烯酯和/或碳酸丙烯酯；
    优选地，所述石墨、碳黑、羧甲基纤维素纳、聚丙烯酸类粘结剂和负极添加剂的质量比为(90～97):(0.6～2.0):(0.2～1.5):(1.5～5):(1～5)；
    优选地，所述负极极片的压实密度为1.55～1.65g/cm 3。
  13. 如权利要求7-12任一项所述的制备方法，其中，步骤(3)所述隔离膜包括基膜和涂覆在基膜至少一面上的陶瓷涂层；
    优选地，所述基膜包括聚烯烃膜、聚氨酯膜、芳纶膜或无纺布中的任意一种或至少两种的组合；
    优选地，所述陶瓷涂层包括氧化铝涂层、氧化硅涂层、硫酸钡涂层或勃姆石涂层中的任意一种或至少两种的组合；
    优选地，所述隔离膜的孔隙率为30～60％；
    优选地，所述隔离膜的厚度为12～30μm。
  14. 如权利要求7-13任一项所述的制备方法，其中，步骤(3)所述卷绕包括将步骤(1)得到的正极极片、隔离膜和步骤(2)得到的负极极片进行整体卷绕后形成留白卷绕的方形电芯，在电芯两侧的卷绕留白处，各堆叠一个电阻片或箔片；
    优选地，所述电阻片或箔片位于所述卷绕的方形电芯中部。
  15. 如权利要求7-14任一项所述的制备方法，其中，步骤(3)所述注液后进行化成；
    优选地，所述化成包括一步化成、二步化成和三步化成；
    优选地，所述一步化成的电流为0.06～0.1C；
    优选地，所述一步化成的时间为0.5～1.5h；
    优选地，所述二步化成的电流为0.12～0.18C；
    优选地，所述二步化成的时间为1.5～2.5h；
    优选地，所述三步化成的电流为0.24～0.3C；
    优选地，所述三步化成的时间为0.5～1.5h；
    优选地，所述化成后电池的电量为65～75％SOC；
    优选地，所述化成后进行老化、补液、封口及分容；
    优选地，所述老化的时间为24～120h。
PCT/CN2022/100629 2021-06-23 2022-06-23 一种锂离子电池及其制备方法 WO2022268147A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110700090.5A CN113422044A (zh) 2021-06-23 2021-06-23 一种锂离子电池及其制备方法
CN202110700090.5 2021-06-23

Publications (1)

Publication Number Publication Date
WO2022268147A1 true WO2022268147A1 (zh) 2022-12-29

Family

ID=77717523

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/100629 WO2022268147A1 (zh) 2021-06-23 2022-06-23 一种锂离子电池及其制备方法

Country Status (2)

Country Link
CN (1) CN113422044A (zh)
WO (1) WO2022268147A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024146477A1 (zh) * 2023-01-05 2024-07-11 宁德时代新能源科技股份有限公司 电池单体、电池和用电设备
WO2024183659A1 (zh) * 2023-03-03 2024-09-12 微宏动力系统（湖州）有限公司 极片复合粘结剂、其制备方法及应用

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113422044A (zh) * 2021-06-23 2021-09-21 中国第一汽车股份有限公司 一种锂离子电池及其制备方法
CN115084447A (zh) * 2022-07-08 2022-09-20 合肥国轩高科动力能源有限公司 一种用于电化学预锂的电芯卷绕方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014009117A (ja) * 2012-06-28 2014-01-20 Jgc Catalysts & Chemicals Ltd リチウム複合酸化物の製造方法、その製造方法によって得られるリチウム複合酸化物、それを含む二次電池用正極活物質、それを含む二次電池用正極、およびそれを正極として用いるリチウムイオン二次電池
CN106684458A (zh) * 2017-01-22 2017-05-17 湖南立方新能源科技有限责任公司 一种改善低温充放电性能的锂离子电池及其制备方法
CN111653732A (zh) * 2019-03-04 2020-09-11 广州汽车集团股份有限公司 一种正极材料、正极极片及锂离子电池
CN111868993A (zh) * 2018-02-22 2020-10-30 三洋电机株式会社 非水电解质二次电池
CN113422044A (zh) * 2021-06-23 2021-09-21 中国第一汽车股份有限公司 一种锂离子电池及其制备方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4441935B2 (ja) * 1998-06-09 2010-03-31 パナソニック株式会社 非水電解液二次電池用負極およびそれを用いた電池
CN110402519A (zh) * 2017-03-22 2019-11-01 通用汽车环球科技运作有限责任公司 自动加热蓄电池
CN108172837A (zh) * 2018-01-24 2018-06-15 广州鹏辉能源科技股份有限公司 锂离子电池负极材料、锂离子电池负极片及其制备方法和锂离子电池
CN109904525A (zh) * 2019-01-29 2019-06-18 中国科学院金属研究所 一种类叠片、留白卷绕的方形锂离子电池
CN109888368A (zh) * 2019-03-05 2019-06-14 深圳鸿鹏新能源科技有限公司 低温锂离子电池
CN110380034A (zh) * 2019-07-23 2019-10-25 合肥国轩高科动力能源有限公司 一种锂离子电池的正极材料及含有其的全电池和制法
EP4071846A4 (en) * 2019-12-02 2024-03-27 Contemporary Amperex Technology Co., Limited POSITIVE ELECTRODE SHEET FOR RECHARGEABLE BATTERY, RECHARGEABLE BATTERY, BATTERY MODULE, BATTERY PACK AND DEVICE
CN111640912A (zh) * 2020-05-13 2020-09-08 力神动力电池系统有限公司 一种正极极片及其制备方法和锂离子二次电池
CN112151794A (zh) * 2020-10-22 2020-12-29 珠海冠宇电池股份有限公司 一种可大倍率放电的正极片及包括该正极片的锂离子电池
CN112751032A (zh) * 2020-12-30 2021-05-04 上海瑞浦青创新能源有限公司 锂离子二次电池及其正极极片

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014009117A (ja) * 2012-06-28 2014-01-20 Jgc Catalysts & Chemicals Ltd リチウム複合酸化物の製造方法、その製造方法によって得られるリチウム複合酸化物、それを含む二次電池用正極活物質、それを含む二次電池用正極、およびそれを正極として用いるリチウムイオン二次電池
CN106684458A (zh) * 2017-01-22 2017-05-17 湖南立方新能源科技有限责任公司 一种改善低温充放电性能的锂离子电池及其制备方法
CN111868993A (zh) * 2018-02-22 2020-10-30 三洋电机株式会社 非水电解质二次电池
CN111653732A (zh) * 2019-03-04 2020-09-11 广州汽车集团股份有限公司 一种正极材料、正极极片及锂离子电池
CN113422044A (zh) * 2021-06-23 2021-09-21 中国第一汽车股份有限公司 一种锂离子电池及其制备方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024146477A1 (zh) * 2023-01-05 2024-07-11 宁德时代新能源科技股份有限公司 电池单体、电池和用电设备
WO2024183659A1 (zh) * 2023-03-03 2024-09-12 微宏动力系统（湖州）有限公司 极片复合粘结剂、其制备方法及应用

Also Published As

Publication number Publication date
CN113422044A (zh) 2021-09-21

Similar Documents

Publication Publication Date Title
JP7159459B2 (ja) リチウムイオン二次電池
WO2022268147A1 (zh) 一种锂离子电池及其制备方法
WO2022206877A1 (zh) 电化学装置及电子装置
JP2023534339A (ja) 電気化学装置及び電子装置
EP2704248A1 (en) Polyimide capacitance battery and manufacturing method thereof
TW200937707A (en) Anode and secondary battery
WO2021023131A1 (zh) 电解液、锂离子电池及装置
JP2023516413A (ja) 負極活物質材料、並びに、それを用いた電気化学装置及び電子装置
WO2022161070A1 (zh) 一种安全型锂离子电池及其制备方法
WO2023070992A1 (zh) 电化学装置及包括其的电子装置
CN113066954B (zh) 一种负极片及其应用
CN104466171A (zh) 一种应急启动用锂离子电池
CN109802094A (zh) 一种低温磷酸铁锂电池及其制备方法
WO2018059180A1 (zh) 一种高功率高能量化学电源及其制备方法
US20230268515A1 (en) Lithium ion battery
WO2012124525A1 (ja) 非水電解質二次電池及びその製造方法
WO2023070268A1 (zh) 一种电化学装置及包含该电化学装置的用电装置
WO2024183803A1 (zh) 一种复合磷酸锰铁锂正极材料及其制备方法和应用
WO2024153145A1 (zh) 一种正极材料及包含该正极材料的电池
WO2024179295A1 (zh) 电化学装置以及用电设备
WO2013029208A1 (zh) 高比能富锂多元系锂离子蓄电池及其制造方法
WO2023087209A1 (zh) 电化学装置及电子装置
CN103915603B (zh) 高低温性能兼顾高功率的锂离子电池
CN219534609U (zh) 一种卷绕电芯和二次电池
CN210379299U (zh) 一种高容量三元二次电池防过充的电池

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: 22827639

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22827639

Country of ref document: EP

Kind code of ref document: A1