WO2024012166A1 - Batterie rechargeable et appareil électrique - Google Patents

Batterie rechargeable et appareil électrique Download PDF

Info

Publication number
WO2024012166A1
WO2024012166A1 PCT/CN2023/101557 CN2023101557W WO2024012166A1 WO 2024012166 A1 WO2024012166 A1 WO 2024012166A1 CN 2023101557 W CN2023101557 W CN 2023101557W WO 2024012166 A1 WO2024012166 A1 WO 2024012166A1
Authority
WO
WIPO (PCT)
Prior art keywords
secondary battery
negative electrode
negative
active coating
active material
Prior art date
Application number
PCT/CN2023/101557
Other languages
English (en)
Chinese (zh)
Inventor
付成华
欧阳少聪
许宝云
叶永煌
林运美
Original Assignee
宁德时代新能源科技股份有限公司
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 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Publication of WO2024012166A1 publication Critical patent/WO2024012166A1/fr

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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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 invention relates to the field of battery technology, and in particular to a secondary battery and an electrical device.
  • Secondary batteries are widely used in various consumer electronics and electric vehicles due to their outstanding characteristics such as light weight, no pollution, and no memory effect.
  • secondary batteries generally have problems such as increased battery internal resistance, reduced discharge performance, and significantly reduced capacity retention at low temperatures, especially when the temperature is below 0°C.
  • One method is to improve low-temperature performance by increasing the ambient temperature, such as adding a heating module to the secondary battery. However, this will increase the size of the secondary battery.
  • Another method is to improve the low-temperature charging method of batteries. However, this method is difficult to balance the safety performance and energy density of secondary batteries in low-temperature environments.
  • a first aspect of the present application provides a secondary battery, including a negative electrode sheet.
  • the negative electrode sheet includes a negative electrode current collector, a first negative electrode active coating, and a second negative electrode active coating.
  • the first negative electrode active coating Disposed on at least one surface of the negative electrode current collector, the second negative electrode active coating is provided between the first negative electrode active coating and the negative electrode current collector, and the impedance of the first negative electrode active coating Less than the impedance of the second negative active coating, the capacity of the first negative active coating Denoted as C 1 ;
  • the secondary battery is rapidly thermally charged from the initial temperature T 0 at a charging rate of 0.3C to 5C until the temperature rises ⁇ T.
  • the capacity of the secondary battery at the end of the rapid thermal charging is recorded as C 0 ;
  • T 0 is - 20°C ⁇ 0°C, ⁇ T ⁇ 5°C;
  • the secondary battery satisfies: C 1 ⁇ C 0 .
  • the secondary battery satisfies: 2C 0 ⁇ C 1 ⁇ C 0 .
  • 1.5C 0 ⁇ C 1 ⁇ C 0 1.5C 0 ⁇ C 1 ⁇ C 0 .
  • the temperature of the secondary battery is increased by ⁇ T to the target temperature T 1 , and T 1 is -5°C to 15°C.
  • T 1 is -10°C to 5°C.
  • T 0 is -20°C to -10°C.
  • ⁇ T 10°C.
  • the first negative active coating includes a first negative active material, and the total mass of the first negative active material is recorded as m 1 in g;
  • the gram capacity is recorded as a, and the unit is A ⁇ h/g;
  • the total capacity of the secondary battery is recorded as C Z , and the unit is A ⁇ h;
  • the capacity of the second negative active coating is recorded as C 2 , and the unit is A ⁇ h;
  • the second negative active coating includes a second negative active material.
  • the total mass of the second negative active material is m 2 in g.
  • the gram capacity of the second negative active material is b in unit. A ⁇ h/g;
  • the first negative active material is selected from natural graphite, soft At least one of carbon, hard carbon and coated graphite, the coating layer of the coated graphite contains at least one of soft carbon and hard carbon, the second negative active material is selected from artificial graphite.
  • the average volume particle diameter Dv50 of the first negative active material is smaller than the average volume particle diameter Dv50 of the second negative active material.
  • the average volume particle size Dv50 of the first negative active material is 3 to 12 ⁇ m, optionally 6 to 12 ⁇ m.
  • the average volume particle size Dv50 of the second negative active material is 9 to 17 ⁇ m.
  • the porosity of the first negative active coating is greater than the porosity of the second negative active coating.
  • the porosity of the first negative active coating is 25% to 40%.
  • the porosity of the second negative active coating is 20% to 30%.
  • the charging method of the secondary battery at temperature T 0 includes the following steps S10-S20:
  • Step S10 The secondary battery is charged rapidly from the initial temperature T 0 at a charging rate of 0.3C to 5C until the temperature rises ⁇ T, so that the temperature reaches the target temperature T 1 ;
  • Step S20 The secondary battery continues to be charged from the target temperature T 1 to 80% SOC to 100% SOC at a charging rate of 0.5C to 5C.
  • the unit of C 1 is A ⁇ h
  • the polarization voltage of the secondary battery in the rapid thermal charging is U J
  • the balance voltage of the secondary battery is UP
  • the units of U J and UP are V
  • the rapid thermal charging charges The capacity of the above-mentioned secondary battery is recorded as C 0 ';
  • the mass of the secondary battery is denoted as m
  • the average specific heat capacity of the secondary battery is denoted as C
  • Q 1 m*C* ⁇ T.
  • a second aspect of the present application provides an electrical device, including the secondary battery of the first aspect of the present application.
  • the negative electrode plate of the secondary battery of the present application is provided with a first negative electrode active coating and a second negative electrode active coating with different impedances, and the first negative electrode active coating with smaller impedance is arranged between the second negative electrode active coating.
  • the capacity C 1 of the first negative electrode active coating to be greater than or equal to the capacity C 0 of the secondary battery at the end of rapid thermal charging at the low ambient temperature T 0 through the above-mentioned specific large charging rate, so that the first The negative active coating meets the capacity requirements of rapid thermal charging and increases the temperature of the secondary battery by ⁇ T from the lower initial temperature T 0 , thus improving the low-temperature lithium evolution window, thus reducing the lithium evolution problem under traditional low-temperature charging and improving safety. performance; at the same time, the second negative electrode active coating meets the overall energy density demand of the secondary battery in a low-temperature environment. In this way, the above-mentioned secondary battery can take into account both safety performance and energy density in low-temperature environments.
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • Figure 2 is a schematic cross-sectional structural view of the negative electrode tab in the secondary battery according to an embodiment of the present application shown in Figure 1;
  • FIG. 3 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • Figure 4 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 5 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 6 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 5 .
  • FIG. 7 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.
  • Ranges disclosed herein are defined in terms of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive of the endpoints, and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, understand that ranges of 60-110 and 80-120 are also expected. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.
  • the numerical range “a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range “0-5" means that all real numbers between "0-5" have been listed in this article, and "0-5" is just an abbreviation of these numerical combinations.
  • a certain parameter is an integer ⁇ 2
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • steps (c) means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c). , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b), etc.
  • condition "A or B” is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; Or both A and B are true (or exist).
  • a secondary battery is provided.
  • a secondary battery typically includes a positive electrode plate, a negative electrode plate, an electrolyte and a separator.
  • active ions are inserted and detached back and forth between the positive and negative electrodes.
  • the electrolyte plays a role in conducting ions between the positive and negative electrodes.
  • the isolation film is placed between the positive electrode piece and the negative electrode piece. It mainly prevents the positive and negative electrodes from short-circuiting and allows ions to pass through.
  • FIG. 1 shows a square-structured secondary battery 5 as an example.
  • the negative electrode sheet includes a negative electrode current collector, a first negative electrode active coating and a second negative electrode active coating.
  • the first negative active coating is disposed on at least one surface of the negative current collector, and the second negative active coating is disposed between the first negative active coating and the negative current collector.
  • the first negative electrode active coating layer is disposed on the surface of the second negative electrode active coating layer away from the negative electrode current collector.
  • the resistance of the first negative active coating is less than the resistance of the second negative active coating, and the capacity of the first negative active coating is recorded as C 1 .
  • the secondary battery is rapidly charged from the initial temperature T 0 at a charging rate of 0.3C to 5C until the temperature rises ⁇ T.
  • the capacity of the secondary battery at the end of the rapid thermal charge is recorded as C 0 ;
  • T 0 is -20°C to 0°C.
  • the secondary battery satisfies: C 1 ⁇ C 0 .
  • the general charging rate is 0.02C and below; in this application, in an environment where T 0 is -20°C ⁇ 0°C, the charging rate is controlled at 0.3 C ⁇ 5C is a relatively large charging rate.
  • the negative electrode plate of the secondary battery of the present application is provided with a first negative electrode active coating and a second negative electrode active coating with different impedances, and the first negative electrode active coating with smaller impedance is arranged on the third negative electrode active coating.
  • the capacity C 1 of the first negative electrode active coating is greater than or equal to the capacity C of the secondary battery at the end of rapid thermal charging at the low temperature ambient temperature T 0 through the above-mentioned specific large charging rate.
  • the first negative electrode active coating to meet the capacity requirements of rapid thermal charging, and increasing the temperature of the secondary battery by ⁇ T from the lower initial temperature T 0 , thereby improving the low-temperature lithium evolution window, thereby reducing the risk of lithium evolution under traditional low-temperature charging. It eliminates the problem of lithium precipitation and improves safety performance; at the same time, the second negative electrode active coating is used to meet the overall energy density demand of secondary batteries in low-temperature environments. In this way, the above-mentioned secondary battery can take into account both safety performance and energy density in low-temperature environments.
  • the negative electrode current collector has two opposite surfaces in its own thickness direction, and the second negative electrode active coating is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the second negative electrode active coating layer may be provided on two opposite surfaces of the negative electrode current collector; the first negative electrode active material may also be provided on the two second negative electrode active coating layers on both surfaces thereof.
  • the negative electrode sheet 7 includes a negative electrode current collector 73 , a first negative electrode active coating 71 and a second negative electrode active coating 72 .
  • the first negative active coating 71 is provided on a surface of the negative current collector 73
  • the second negative active coating 72 is provided between the first negative active coating 71 and the negative current collector 73 .
  • the secondary battery satisfies: 2C 0 ⁇ C 1 ⁇ C 0 .
  • C 1 can be C 0 , 1.3C 0 , 1.5C 0 , 2C 0 . Further, 1.5C 0 ⁇ C 1 ⁇ C 0 ; further, 1.3C 0 ⁇ C 1 ⁇ C 0 .
  • T 0 can be -20°C, -15°C, -10°C, -5°C, -2°C, or 0°C. Further, T 0 is -20°C to -10°C. It can be understood that ⁇ T can be 5°C, 6°C, 8°C, 10°C, 15°C, 18°C, 20°C, 23°C, or 25°C. In some embodiments, ⁇ T ⁇ 10°C; further, 35°C ⁇ T ⁇ 10°C.
  • the temperature of the secondary battery is increased by ⁇ T to the target temperature T 1 , where T 1 is -10°C to 15°C.
  • T 1 is -10°C to 5°C.
  • T 1 is -5°C to 5°C.
  • the target temperature can reach the normal charging rate requirement within this temperature range.
  • the above-mentioned charging method of the secondary battery at temperature T 0 includes the following steps S10-S20:
  • Step S10 The secondary battery is rapidly charged from the initial temperature T 0 at a charging rate of 0.3C to 5C until the temperature rises ⁇ T, so that the temperature reaches the target temperature T 1 ; T 0 is -20°C to 0°C, ⁇ T ⁇ 5 °C.
  • the charging rate of 0.3C to 5C at the initial temperature T 0 is a relatively large charging rate.
  • Step S20 The secondary battery continues to be charged from the target temperature T1 to 80% SOC to 100% SOC (fully charged) at a charging rate of 0.5C to 5C.
  • the charging window is relaxed, and the charging rate of 0.5C to 5C is a relatively conventional charging rate.
  • the charging rate in step S20 can be 0.5C, 1C, 1.5C, 1.7C, 2.9C, 3C, 4C, 5C; further, the charging rate in step S20 is 0.5C ⁇ 3C.
  • step S10 The above-mentioned secondary battery is subjected to high-rate rapid thermal charging at low temperature through step S10.
  • the time required for rapid thermal charging is short.
  • the charging curve of the secondary battery during rapid thermal charging is deviated from the equilibrium potential as much as possible to generate as much energy as possible.
  • More polarization heat is used to increase the temperature rise of the battery core, thereby improving the low-temperature lithium evolution window.
  • you cannot use high-rate continuous charging to 80% SOC ⁇ 100% SOC because the battery charging window is narrow at this time. If you continue to use high-rate rapid thermal charging strategy to charge to 80% SOC ⁇ 100% SOC, the secondary battery will be easily analyzed. Lithium, causing safety accidents. Therefore, step S20 uses the normal charging rate to charge when the target temperature T 1 is reached to ensure safety.
  • the above-mentioned secondary battery of the present application adopts the above-mentioned charging method and at the same time optimizes the negative electrode plate to match Equipped with this charging method, the above-mentioned secondary battery can take into account both safety performance and energy density in low-temperature environments.
  • the unit of C 1 is A ⁇ h; the theoretical heat required for rapid thermal charging is denoted as Q 1 , and the unit of Q 1 is J.
  • the polarization voltage of the secondary battery during rapid thermal charging is U J
  • the equilibrium voltage of the secondary battery is UP
  • the units of U J and UP are V; in this way, the first negative active material of the secondary battery during rapid thermal charging
  • the polarization heat generated during the process Q 2 (U J -UP )*C 0 '*3600.
  • the mass m of the secondary battery refers to the total mass including the outer packaging, top cover and bare cells.
  • the average specific heat capacity of a secondary battery is the energy required for every 1°C increase in temperature of the secondary battery as a whole.
  • the average specific heat capacity C of the secondary battery can be tested by the following method: charge and discharge the secondary battery in an accelerated adiabatic calorimeter (ARC) or homemade adiabatic equipment, and record the voltage, temperature, charge and discharge time and other data of the secondary battery.
  • ARC accelerated adiabatic calorimeter
  • Rapid thermal charging is a polarization process of high-rate charging, and U J refers to the average voltage during the rapid thermal charging stage.
  • U P refers to the voltage charged at 0.05C at 25°C. At this time, the charging rate is small enough and there is no polarization voltage, so it is a balanced voltage.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil copper foil can be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base material.
  • the composite current collector can be The metal material is formed on the polymer material substrate.
  • metal materials include but are not limited to copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.
  • Polymer material substrates include but are not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE).
  • the first negative active coating includes a first negative active material.
  • the second negative active coating includes a second negative active material.
  • the first negative electrode active material and the second negative electrode active material may adopt negative electrode active materials known in the art for use in batteries.
  • the first negative active coating and the second negative active coating optionally further include a binder.
  • the binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), polysodium acrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), poly At least one of methacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the first negative active coating and the second negative active coating optionally further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the first negative active coating and the second negative active coating optionally include other auxiliaries, such as thickeners (such as sodium carboxymethylcellulose (CMC-Na)) and the like.
  • thickeners such as sodium carboxymethylcellulose (CMC-Na)
  • the negative electrode sheet can be prepared by using the above-mentioned components for preparing the negative electrode sheet, such as the first negative active material or the second negative active material, the conductive agent, the binder, and any other components.
  • the particles are dispersed in a solvent (such as deionized water) to form a first negative electrode slurry and a second negative electrode slurry respectively; the second negative electrode slurry and the first negative electrode slurry are coated on the negative electrode current collector, dried, After cold pressing and other processes, the negative electrode piece can be obtained.
  • a solvent such as deionized water
  • the capacity of the second negative active coating is recorded as C 2 , and the unit is A ⁇ h.
  • the total mass of the second negative active material in the second negative active coating is recorded as m 2 in g; the gram capacity of the second negative active material is recorded as b in A ⁇ h/g.
  • the first negative active material is selected from at least one of natural graphite, soft carbon, hard carbon and coated graphite, and the coating layer of the coated graphite contains at least one of soft carbon and hard carbon. A sort of.
  • the second negative active material is selected from artificial graphite.
  • the cost of the secondary battery can also be reduced by matching specific types of the first negative active material and the second negative active material.
  • the average volume particle diameter Dv50 of the first negative active material is smaller than the average volume particle diameter Dv50 of the second negative active material. In this way, by defining the relative sizes of the average volume particle diameters of the first and second negative electrode active materials, so that the resistance of the first negative electrode active coating is smaller than the resistance of the second negative electrode active coating, the first negative electrode active coating can be layer to better meet the capacity needs of fast thermal charging.
  • Dv50 refers to the particle size corresponding to when the cumulative particle size distribution number of particles reaches 50% in the particle size distribution curve. Its physical meaning is that 50% of the particles have a particle size smaller (or larger) than it.
  • Dv50 can be easily measured using a laser particle size analyzer, such as the Mastersizer 2000E laser particle size analyzer of Malvern Instruments Co., Ltd. in the United Kingdom, referring to the GB/T 19077-2016 particle size distribution laser diffraction method.
  • the average volume particle diameter Dv50 of the first negative active material is 3 to 12 ⁇ m; optionally, it is 6 to 12 ⁇ m.
  • the average volume particle diameter Dv50 of the second negative electrode active material is 9 to 17 ⁇ m.
  • the porosity of the first negative active coating is greater than the porosity of the second negative active coating. In this way, by defining the relative sizes of the porosity of the first and second negative electrode active materials, the first negative electrode active coating can better meet the capacity requirements of rapid thermal charging.
  • the porosity of the first negative active coating layer is 25% to 40%.
  • the porosity of the second negative active coating layer is 20% to 30%.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces facing each other in its own thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil can be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. Composite current collectors can be made by adding gold The metal material is formed on the polymer material substrate.
  • metal materials include but are not limited to aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.
  • Polymer material substrates include but are not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) at least one.
  • the cathode active material may be a cathode active material known in the art for batteries.
  • the cathode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials of batteries can also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination.
  • lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO 2 ), lithium nickel oxides (such as LiNiO 2 ), lithium manganese oxides (such as LiMnO 2 , LiMn 2 O 4 ), lithium Nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (can also be abbreviated to NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (can also be abbreviated to NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (can also be abbreviated to NCM 622 ), LiNi At least one of 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as Li Li
  • the olivine structure contains Examples of lithium phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), composites of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), lithium manganese phosphate and carbon. At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • composites of lithium iron phosphate and carbon such as LiMnPO 4
  • LiMnPO 4 lithium manganese phosphate and carbon.
  • At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon At least one of composite materials, lithium iron manganese phosphate, and composite materials of lithium iron manganese phosphate and carbon.
  • the positive electrode film layer optionally further includes a binder.
  • the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene At least one of ethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • the positive electrode film layer optionally further includes a conductive agent.
  • the conductive agent may include superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphite At least one of alkenes and carbon nanofibers.
  • the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components in a solvent (such as N -methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode piece can be obtained.
  • a solvent such as N -methylpyrrolidone
  • the electrolyte plays a role in conducting ions between the positive and negative electrodes.
  • the type of electrolyte in this application can be selected according to needs.
  • the electrolyte can be liquid, gel, or completely solid.
  • the electrolyte is an electrolyte solution.
  • the electrolyte solution includes electrolyte salts and solvents.
  • the electrolyte salt may be selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonimide, lithium bistrifluoromethanesulfonimide, trifluoromethane At least one of lithium sulfonate, lithium difluorophosphate, lithium difluoroborate, lithium dioxaloborate, lithium difluorodioxalate phosphate and lithium tetrafluoroxalate phosphate.
  • the solvent may be selected from the group consisting of ethylene carbonate, propylene carbonate, methylethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, Butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate At least one of ester, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte optionally further includes additives.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain properties of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.
  • the secondary battery further includes a separator film.
  • the type of isolation film used in this application Any well-known porous structure isolation membrane with good chemical stability and mechanical stability can be used.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation film can be a single-layer film or a multi-layer composite film. When the isolation film is a multi-layer composite film, the materials of each layer can be the same or different.
  • the positive electrode piece, the negative electrode piece and the separator film can be made into an electrode assembly through a winding process or a lamination process.
  • the secondary battery may include an outer packaging.
  • the outer packaging can be used to package the above-mentioned electrode assembly and electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft bag, such as a bag-type soft bag.
  • the material of the soft bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, polybutylene succinate, and the like.
  • the shape of the secondary battery of the present application can be cylindrical, square or any other shape.
  • FIG. 1 shows a square-structured secondary battery 5 as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity.
  • the housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 can cover the opening to close the accommodation cavity.
  • the positive electrode piece, the negative electrode piece and the isolation film can be formed into the electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the containing cavity.
  • the electrolyte soaks into the electrode assembly 52 .
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • secondary batteries can be assembled into battery modules, and the number of secondary batteries contained in the battery module can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery module.
  • FIG 4 is a battery module 4 as an example.
  • a plurality of The secondary batteries 5 may be arranged sequentially along the length direction of the battery module 4 .
  • the plurality of secondary batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having a receiving space in which a plurality of secondary batteries 5 are received.
  • the above-mentioned battery modules can also be assembled into a battery pack.
  • the number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select the specific number according to the application and capacity of the battery pack.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box 2 and a lower box 3 .
  • the upper box 2 can be covered with the lower box 3 and form a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application.
  • the secondary battery, battery module, or battery pack may be used as a power source for the electrical device, or may be used as an energy storage unit for the electrical device.
  • the electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, and electric golf carts). , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.
  • FIG. 7 is an electrical device as an example.
  • the electric device 6 is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or the like.
  • a battery pack or battery module can be used.
  • the device may be a mobile phone, a tablet, a laptop, etc.
  • the device is usually required to be thin and light, and a secondary battery can be used as a power source.
  • the negative electrode current collector uses 6 ⁇ m thick copper foil
  • the step of forming a second negative active coating layer Use the second negative active material (artificial graphite): conductive carbon SP: dispersant CMC: binder SBR in the following ratio (96.85%: 0.4%: 1.25%: 1.5%) and mix evenly, then add deionized water and configure Form a slurry with a solid content of about 50%, and then use extrusion coating to coat the surface of the copper foil;
  • second negative active material artificial graphite
  • conductive carbon SP dispersant CMC: binder SBR in the following ratio (96.85%: 0.4%: 1.25%: 1.5%) and mix evenly, then add deionized water and configure Form a slurry with a solid content of about 50%, and then use extrusion coating to coat the surface of the copper foil;
  • a first negative active coating layer is formed.
  • first negative active material natural graphite
  • the negative electrode piece is then prepared through cold pressing, laser die-cutting and other processes;
  • the positive electrode piece, the negative electrode piece and the separator film are rolled to prepare a bare battery core, which is then installed into an aluminum case and prepared through processes such as liquid injection, high temperature standing, formation, aging, and volume separation. Normal lithium-ion battery.
  • the secondary batteries of Examples 2 to 14 and the secondary batteries of Comparative Examples 1 to 3 are similar to the secondary batteries of Example 1, but the composition and product parameters of the battery pole pieces are adjusted. The different product parameters are detailed in the table 1.
  • the first negative active material is natural graphite, and its gram capacity varies slightly with Dv50; the details are as follows:
  • the gram capacity of the first negative active material with Dv50 of 12 ⁇ m is 350 mAh/g;
  • the gram capacity of the first negative active material with Dv50 of 8 ⁇ m is 345 mAh/g;
  • the gram capacity of the first negative active material with Dv50 of 6 ⁇ m is 340 mAh/g.
  • the second negative active material is all artificial graphite, and its gram capacity varies slightly with Dv50; the details are as follows:
  • the gram capacity of the first negative active material with Dv50 of 15 ⁇ m is 360 mAh/g;
  • the gram capacity of the first negative active material with Dv50 of 9 ⁇ m is 347 mAh/g;
  • the first negative electrode active material with a Dv50 of 17 ⁇ m has a gram capacity of 373 mAh/g.
  • the charging method of the secondary battery at ambient temperature T 0 includes the following steps S10-S20:
  • Step S10 Perform the rapid thermal charging of the secondary battery from the initial temperature T 0 at a charging rate of 0.3C to 5C (specific values are shown in Table 1) until the temperature rises ⁇ T, so that the temperature reaches the target temperature T 1 ;
  • Step S20 Continue charging the secondary battery from the target temperature T 1 to 80% SOC at a charging rate of 0.5C to 5C (specific values are shown in Table 1).
  • the starting SOC (i.e. C Q ) of step S10 is 10% SOC
  • the initial temperature T 0 (environmental temperature) is -20°C
  • the charging end SOC (i.e. C 0 ) are both 80% SOC.
  • the total charging time in Table 1 is the sum of the charging times in step S10 and step S20.
  • the polarization voltage of the secondary battery in rapid thermal charging is U J
  • the balance voltage of the secondary battery is UP
  • the units of U J and UP are V;
  • U P refers to the charging voltage of 0.05C at 25°C.
  • C 1 m 1 ⁇ a, where the total mass of the first negative active material is recorded as m 1 in g; the gram capacity of the first negative active material is recorded as a in A ⁇ h/g;
  • Each secondary battery that reaches 80% SOC according to the above low-temperature charging process will be disassembled to observe whether lithium is precipitated at the interface of the negative electrode piece.
  • the evaluation method for the degree of lithium precipitation is as follows:
  • the maximum area of a single lithium precipitation area in the entire negative electrode piece is ⁇ 5*5mm 2 , and the number of lithium precipitation areas in the entire negative electrode piece is ⁇ 1;
  • Moderate lithium precipitation 5*5mm 2 ⁇ The maximum area of a single lithium precipitation area of the entire negative electrode piece is ⁇ 10*10mm 2 , and the number of lithium precipitation areas of the entire negative electrode piece is ⁇ 1;
  • Severe lithium evolution Lithium evolution exists and does not meet the criteria for mild lithium evolution and moderate lithium evolution.
  • Comparative Example 1 adopts the same low-temperature charging process as Example 3.
  • the results show that the secondary battery of Comparative Example 1 has severe lithium deposition.
  • the secondary battery of Comparative Example 2 is the same as Comparative Example 1, but the low-temperature charging process is different.
  • the conventional charging process is used.
  • the results show that no lithium is evaporated, but there is a shortcoming of long charging time. The charging time is several times that of the embodiment. .
  • the structure of the negative electrode plate of the secondary battery of Comparative Example 3 is basically the same as that of the secondary battery of Example 3. The only difference is that in Comparative Example 3, the capacity C 0 charged by the negative electrode plate during the rapid thermal charging stage is larger, and thus Make C 1 ⁇ C 0 , resulting in serious lithium precipitation.
  • Examples 1 to 3 are basically the same, the only difference is that the Dv50 particle size of the first negative electrode active material is different, and the corresponding gram capacity is also different; as the Dv50 particle size of the first negative electrode active material decreases, the first negative electrode The kinetic properties of the active coating are improved, the lithium precipitation problem is improved, and the gram capacity is reduced, resulting in a slight reduction in battery energy density.
  • Embodiments 3 to 5 are basically the same. The only difference is that the porosity of the first negative electrode active coating is different. Specifically, different porosity is obtained by controlling the cold pressing process in the preparation process of the negative electrode sheet; as the porosity increases, The problem of lithium precipitation has been improved, and the battery energy density has been slightly reduced.
  • Embodiments 3, 6 to 7 are basically the same, the only difference lies in the content added in the first negative electrode active coating The amount of the first negative active material is different, thus making C 1 /C Z different, 2C 0 ⁇ C 1 ⁇ C 0 .
  • According to the energy density and lithium deposition performance of the battery optionally, 1.5C 0 ⁇ C 1 ⁇ C 0 .
  • Embodiments 3, 8 to 9 are basically the same, the only difference is that the Dv50 particle size of the second negative electrode active material is different, and the corresponding gram capacity is also different; as the Dv50 particle size of the second negative electrode active material decreases, the second negative electrode active material The kinetic properties of the coating are improved, the lithium precipitation problem is improved, and the gram capacity is reduced, resulting in a slight reduction in battery energy density.
  • Embodiments 3 and 10 to 11 are basically the same. The only difference is that the porosity of the second negative electrode active coating is different. Specifically, different porosity is obtained by controlling the cold pressing process in the preparation process of the negative electrode piece; as the porosity increases, With the increase, the lithium precipitation problem is improved and the battery energy density is slightly reduced.
  • Embodiments 3 and 12 to 13 are basically the same. The only difference lies in the rate of rapid thermal charging. The battery energy density of the battery is maintained at a better level and the lithium deposition problem is improved. Taking into account the lithium deposition situation and the charging time, the rapid thermal charging rate of Embodiment 3 can be selected.
  • Embodiment 14 is basically the same as Embodiment 3, in which the rapid thermal charging rate is the same and the SOC at the end of controlled rapid heating is different. Comparison shows that although lithium precipitation does not occur in Embodiment 14, the total charging time is longer.

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

La présente invention concerne une batterie rechargeable et un appareil électrique. La batterie rechargeable comprend une plaque d'électrode négative, qui comprend un collecteur de courant négatif, un premier revêtement actif négatif et un second revêtement actif négatif, le premier revêtement actif négatif étant disposé sur au moins une surface du collecteur de courant négatif, le second revêtement actif négatif étant disposé entre le premier revêtement actif négatif et le collecteur de courant négatif, l'impédance du premier revêtement actif négatif étant inférieure à l'impédance du second revêtement actif négatif, et la capacité du premier revêtement actif négatif étant désignée par C 1. La batterie rechargeable est soumise à une charge à chauffage rapide à une vitesse de charge de 0,3 à 5 C à partir d'une température initiale T 0 jusqu'à ce que la température soit augmentée de ΔT, et la capacité de la batterie rechargeable est désignée par C 0 lorsque la charge à chauffage rapide se termine ; T 0 va de -20 °C à 0 °C, et ΔT ≥ 5 °C ; et la batterie rechargeable satisfait à C 1 ≥ C 0.
PCT/CN2023/101557 2022-07-11 2023-06-21 Batterie rechargeable et appareil électrique WO2024012166A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210809286.2A CN115832185A (zh) 2022-07-11 2022-07-11 二次电池及用电装置
CN202210809286.2 2022-07-11

Publications (1)

Publication Number Publication Date
WO2024012166A1 true WO2024012166A1 (fr) 2024-01-18

Family

ID=85522791

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/101557 WO2024012166A1 (fr) 2022-07-11 2023-06-21 Batterie rechargeable et appareil électrique

Country Status (2)

Country Link
CN (1) CN115832185A (fr)
WO (1) WO2024012166A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115832185A (zh) * 2022-07-11 2023-03-21 宁德时代新能源科技股份有限公司 二次电池及用电装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111490253A (zh) * 2019-01-29 2020-08-04 宁德时代新能源科技股份有限公司 一种负极极片及其锂离子二次电池
CN111640940A (zh) * 2019-03-01 2020-09-08 宁德时代新能源科技股份有限公司 负极片及二次电池
CN112968148A (zh) * 2021-03-29 2021-06-15 欣旺达电动汽车电池有限公司 一种锂离子电池负极片和锂离子电池
US20210257606A1 (en) * 2020-02-18 2021-08-19 Samsung Electronics Co., Ltd. All-solid secondary battery, and method of manufacturing all-solid secondary battery
CN115832185A (zh) * 2022-07-11 2023-03-21 宁德时代新能源科技股份有限公司 二次电池及用电装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111490253A (zh) * 2019-01-29 2020-08-04 宁德时代新能源科技股份有限公司 一种负极极片及其锂离子二次电池
CN111640940A (zh) * 2019-03-01 2020-09-08 宁德时代新能源科技股份有限公司 负极片及二次电池
US20210257606A1 (en) * 2020-02-18 2021-08-19 Samsung Electronics Co., Ltd. All-solid secondary battery, and method of manufacturing all-solid secondary battery
CN112968148A (zh) * 2021-03-29 2021-06-15 欣旺达电动汽车电池有限公司 一种锂离子电池负极片和锂离子电池
CN115832185A (zh) * 2022-07-11 2023-03-21 宁德时代新能源科技股份有限公司 二次电池及用电装置

Also Published As

Publication number Publication date
CN115832185A (zh) 2023-03-21

Similar Documents

Publication Publication Date Title
WO2023142340A1 (fr) Plaque d'électrode et batterie secondaire la comprenant
WO2024011512A1 (fr) Plaque d'électrode négative, procédé de préparation de plaque d'électrode négative, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique
WO2023082918A1 (fr) Batterie au lithium-ion, module de batterie, bloc-batterie et appareil électrique
WO2024012166A1 (fr) Batterie rechargeable et appareil électrique
WO2023134340A1 (fr) Matériau actif d'électrode négative, plaque d'électrode négative, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique associé
WO2023071807A1 (fr) Membrane et son procédé de préparation, batterie secondaire, module de batterie, bloc-batterie et dispositif consommateur d'énergie
WO2023060529A1 (fr) Batterie aux ions lithium
WO2023137624A1 (fr) Batterie secondaire, module de batterie, bloc-batterie et appareil électrique
WO2023087218A1 (fr) Feuille d'électrode négative et procédé de préparation associé, batterie secondaire, module de batterie, bloc-batterie et appareil consommateur de puissance
WO2023142024A1 (fr) Batterie secondaire ayant une longue durée de vie, module de batterie, bloc-batterie et appareil électrique
WO2023004774A1 (fr) Groupe de batteries, bloc-batterie et appareil électrique
WO2023133825A1 (fr) Bloc-batterie et appareil électrique
WO2023060534A1 (fr) Batterie secondaire
WO2023133882A1 (fr) Séparateur et batterie secondaire associée, module de batterie, bloc-batterie et dispositif électronique
WO2023133833A1 (fr) Batterie secondaire, module de batterie, bloc-batterie et appareil électrique
WO2023141954A1 (fr) Batterie au lithium-ion, module de batterie, bloc-batterie et appareil électrique
WO2024098171A1 (fr) Élément de batterie et son procédé de préparation, batterie secondaire et appareil électrique
WO2023039913A1 (fr) Bloc-batterie et appareil électrique
WO2023050834A1 (fr) Batterie secondaire, module de batterie le contenant, bloc-batterie et dispositif électrique
WO2023065128A1 (fr) Feuille d'électrode, batterie secondaire, module de batterie, bloc-batterie et dispositif électrique
WO2023230954A1 (fr) Batterie rechargeable, module de batterie, bloc-batterie et appareil électrique
WO2024109530A1 (fr) Feuille d'électrode négative et batterie secondaire la comprenant
WO2024044961A1 (fr) Feuille d'électrode négative, batterie secondaire et son procédé de préparation, module de batterie, bloc-batterie et dispositif électrique
WO2024040472A1 (fr) Batterie secondaire, module de batterie, bloc-batterie et appareil électrique
WO2023044752A1 (fr) Batterie au lithium-ion, module de batterie, bloc-batterie et dispositif électrique

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: 23838660

Country of ref document: EP

Kind code of ref document: A1