WO2024098410A1 - 正极浆料的制备方法、二次电池、电池包和用电装置 - Google Patents

正极浆料的制备方法、二次电池、电池包和用电装置 Download PDF

Info

Publication number
WO2024098410A1
WO2024098410A1 PCT/CN2022/131506 CN2022131506W WO2024098410A1 WO 2024098410 A1 WO2024098410 A1 WO 2024098410A1 CN 2022131506 W CN2022131506 W CN 2022131506W WO 2024098410 A1 WO2024098410 A1 WO 2024098410A1
Authority
WO
WIPO (PCT)
Prior art keywords
stirring
slurry
positive electrode
rpm
viscosity
Prior art date
Application number
PCT/CN2022/131506
Other languages
English (en)
French (fr)
Inventor
邢祁
刘会会
欧阳楚英
孙成栋
段连威
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
Priority to PCT/CN2022/131506 priority Critical patent/WO2024098410A1/zh
Publication of WO2024098410A1 publication Critical patent/WO2024098410A1/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
    • H01M4/04—Processes of manufacture in general

Definitions

  • the present application relates to the technical field of secondary batteries, and in particular to a method for preparing a positive electrode slurry for a secondary battery, a secondary battery, a battery pack and an electrical device.
  • secondary batteries are widely used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields.
  • Electrode slurry is the basis for forming electrodes and is also the first step in the production of secondary batteries.
  • the characteristics of electrode slurry have a significant impact on subsequent electrode production and battery performance.
  • the positive electrode slurry is mainly a solid-liquid mixed system formed by positive electrode active materials, conductive agents, binders and solvents. This system is in a metastable state.
  • the slurry preparation process that is, the slurry preparation method, has a crucial influence on the dispersibility, uniformity, stability and other properties of the slurry.
  • the slurry preparation process in the prior art is often a one-step method, in which the components in the positive electrode slurry are directly mixed and stirred.
  • the one-step preparation method cannot meet the manufacturing requirements of binders with different weight average molecular weights, and the slurry preparation process has poor versatility, which is not conducive to reducing manufacturing costs. Therefore, it is necessary to develop a new slurry preparation method that is suitable for binders with different weight average molecular weights.
  • the present application is made in view of the above-mentioned problems, and its purpose is to provide a method for preparing a positive electrode slurry for a secondary battery, so as to be applicable to binders with different weight average molecular weights and improve the coating and processability of the slurry.
  • the present application provides a method for preparing a positive electrode slurry, including first stirring, second stirring, third stirring and fourth stirring; in the first stirring, the conductive agent and the binder are mixed and stirred to prepare a dry mixture; in the second stirring, the solvent and the dry mixture are mixed and stirred to prepare a primary slurry; in the third stirring, the positive electrode active material and the primary slurry are mixed and stirred to prepare a secondary slurry; in the fourth stirring, the solvent is mixed and stirred with the secondary slurry to prepare a positive electrode slurry; the solvent used in the second stirring is the same as the solvent used in the fourth stirring, and based on the total mass of the positive electrode active material, the mass ratio of the solvent used in the second stirring is 35% to 40%, and the mass ratio of the solvent used in the fourth stirring is 5% to 10%.
  • the preparation method of the positive electrode slurry disclosed in the present application is more widely applicable than the existing preparation method of the positive electrode slurry, and is suitable for slurries containing binders with different weight-average molecular weights.
  • the present application reduces the shipping viscosity of the positive electrode slurry by step-by-step slurry mixing, alleviates the gelation phenomenon of the positive electrode slurry, and improves the applicability of the preparation method for high molecular weight binders.
  • the preparation method has a wider universality, expands the process window for coating the positive electrode slurry, and improves the processing performance of the positive electrode slurry.
  • the binder comprises at least one polyvinylidene fluoride having a weight average molecular weight of 400,000 to 1.8 million.
  • the preparation method disclosed in the present application is universal for low molecular weight polyvinylidene fluoride binders and high molecular weight polyvinylidene fluoride binders, can effectively alleviate the gelation phenomenon of different slurries, help improve production efficiency, and broaden the coating window of the slurry.
  • the preparation method disclosed in the present application can be applied to binders with a weight average molecular weight of up to 1.8 million, so that the slurry containing the high weight average molecular weight binder still has low shipping viscosity and anti-gel properties, which can meet the use requirements of the new generation of binders.
  • the binder comprises at least two polyvinylidene fluoride having a weight average molecular weight difference of no more than 1.8 million.
  • the positive electrode slurry prepared by the method of the present application can effectively exert the characteristics of polyvinylidene fluoride binders of different molecular weights, and through the mutual coordination of large and small segments and steric hindrance, the slurry has a good gel state, and the slurry has a low shipping viscosity and a viscosity after standing for 24 hours.
  • the rotation speed of the first stirring is 0.
  • Controlling the rotation speed of the first stirring to 0 reduces the shear force of the first stirring, reduces the possibility of excessive crushing of the conductive agent and the binder, ensures that the conductive agent and the binder have a certain particle size and specific surface area, helps to improve the dispersion effect of the conductive agent and the binder, reduces the viscosity of the slurry at delivery and the viscosity after standing for 24 hours, slows down the gelation phenomenon of the slurry, and improves the stability of the slurry.
  • the stirring time of the first stirring is 15 minutes to 30 minutes.
  • the stirring time of the first stirring in the appropriate range makes the slurry have low shipping viscosity and viscosity after standing and storing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the first stirring in the appropriate range can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry.
  • the revolution speed of the first stirring is 10 rpm to 20 rpm.
  • the revolution speed of the first stirring in a suitable range makes the slurry have a low shipping viscosity and a viscosity after standing and storing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • the revolution speed of the first stirring in a suitable range can be controlled to be 10 rpm to 20 rpm without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gel phenomenon of the slurry, thereby reducing the power of the agitator, saving energy, and taking into account both the quality and cost of the slurry.
  • the stirring time of the second stirring is 50 to 80 minutes.
  • the stirring time of the second stirring in the appropriate range makes the slurry have a low shipping viscosity and a viscosity after standing and storing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the second stirring in the appropriate range can reduce the working time of the slurry preparation, improve the working efficiency of the slurry preparation, and reduce the cost without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry.
  • the revolution speed of the second stirring is 15 rpm to 30 rpm.
  • the revolution speed of the second stirring in a suitable range can slow down the gelation of the slurry, improve the stability of the slurry, broaden the process window, and make the slurry have a low shipping viscosity and a viscosity after standing for 24 hours, so that the slurry has good coating performance and processing performance.
  • the second stirring rotation speed is 800 rpm to 1300 rpm.
  • the second stirring rotation speed in a suitable range can reduce the viscosity of the slurry at the time of shipment and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • the stirring time of the third stirring is 100 minutes to 130 minutes.
  • the stirring time of the third stirring in the appropriate range makes the slurry have low shipping viscosity and viscosity after standing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the third stirring in the appropriate range can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gel phenomenon of the slurry.
  • the revolution speed of the third stirring is 20 rpm to 40 rpm.
  • the revolution speed of the third stirring in the appropriate range can reduce the viscosity of the slurry at the time of shipment and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • the rotation speed of the third stirring is 1000 rpm to 1300 rpm.
  • the rotation speed of the third stirring in the appropriate range can reduce the viscosity of the slurry at the time of shipment and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • the stirring time of the fourth stirring is 30 minutes to 50 minutes.
  • the stirring time of the fourth stirring in a suitable range helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, slow down the gelation phenomenon of the slurry, improve the stability of the slurry, and broaden the process window.
  • the revolution speed of the fourth stirring is 20 rpm to 40 rpm.
  • the revolution speed of the fourth stirring in a suitable range helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improves the coating and processability of the slurry, and makes the slurry have good anti-gel properties.
  • the fourth stirring rotation speed is 1000 rpm to 1300 rpm.
  • the fourth stirring rotation speed in a suitable range helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improves the coating and processability of the slurry, and makes the slurry have good anti-gel properties.
  • the mass of the positive electrode active material is 900kg to 1300kg.
  • the preparation method is suitable for industrial mass production of slurry, effectively overcoming the problems of poor batch stability and poor precision of raw materials encountered from laboratory production to industrial mass production, and is conducive to improving production efficiency.
  • the mass ratio of the positive electrode active material, the binder, and the conductive agent is (95-98.5): (1-3): (0.5-1).
  • the positive electrode slurry within the above range has good processing performance and makes the formed positive electrode sheet have excellent electrochemical performance.
  • the positive electrode active material is one or more of lithium iron phosphate, lithium cobalt oxide, lithium titanate, and lithium nickel cobalt manganese oxide.
  • the above positive electrode active materials make the battery have high energy density, which is conducive to improving the cycle performance of the battery.
  • the second aspect of the present application also provides a positive electrode slurry, the solid content of the positive electrode slurry is 65% to 70%, the initial viscosity of the positive electrode slurry is 1000 to 35000 mPa ⁇ s, and after the positive electrode slurry is left to stand for 24 hours, the viscosity of the positive electrode slurry does not exceed 50000 mPa ⁇ s.
  • the positive electrode slurry has good processing performance and storage performance, and can improve production efficiency and broaden the coating process window.
  • the positive electrode slurry is prepared by the preparation method described in the first aspect.
  • the third aspect of the present application provides a secondary battery, comprising a positive electrode sheet, a separator, a negative electrode sheet and an electrolyte, wherein the positive electrode sheet is prepared from the positive electrode slurry prepared by the preparation method described in the first aspect.
  • the positive electrode sheet has high quality and production efficiency.
  • the secondary battery is any one of a lithium ion battery, a sodium ion battery, a magnesium ion battery, and a potassium ion battery.
  • the fourth aspect of the present application further provides a battery module, comprising the secondary battery described in the third aspect of the present application.
  • a fifth aspect of the present application provides a battery pack, comprising the secondary battery described in the third aspect of the present application or the battery module of the fourth aspect of the present application.
  • the sixth aspect of the present application provides an electrical device comprising at least one selected from the secondary battery of the third aspect of the present application, the battery module of the fourth aspect of the present application, or the battery pack of the fifth aspect of the present application.
  • FIG1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG2 is an exploded view of the secondary battery of one embodiment of the present application shown in FIG1 ;
  • FIG3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • FIG4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG4 ;
  • FIG6 is a schematic diagram of an electric device using a secondary battery as a power source according to an embodiment of the present application.
  • range disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range.
  • the range defined in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60-120 and 80-110 is listed for a specific parameter, it is understood that the range of 60-110 and 80-120 is also expected.
  • the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • 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.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: 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).
  • the positive electrode slurry is mainly a solid-liquid mixed system formed by positive electrode active materials, conductive agents, binders and solvents.
  • slurry mixing is often carried out through stirring, ball milling, ultrasound and other processes.
  • the slurry mixing process in the prior art is usually only applicable to slurry systems with fixed components, and has poor versatility. After the physical properties of the components in the slurry change, the slurry mixing process often needs to be adjusted.
  • the slurry mixing process in the prior art cannot be applied to high molecular weight binders.
  • the slurries using binders of different molecular weights have great differences in performance after being prepared using the same slurry mixing process in the prior art.
  • the slurry has a high viscosity when shipped, and it is difficult to meet the subsequent production requirements of pole pieces.
  • the present application proposes a method for preparing a positive electrode slurry, including first stirring, second stirring, third stirring and fourth stirring; in the first stirring, the conductive agent and the binder are mixed and stirred to prepare a dry mixture; in the second stirring, the solvent and the dry mixture are mixed and stirred to prepare a primary slurry; in the third stirring, the positive electrode active material and the primary slurry are mixed and stirred to prepare a secondary slurry; in the fourth stirring, the solvent and the secondary slurry are mixed and stirred to prepare a positive electrode slurry; the solvent used in the second stirring is the same as the solvent used in the fourth stirring, and based on the total mass of the positive electrode active material, the mass ratio of the solvent used in the second stirring is 35% to 40%, and the mass ratio of the solvent used in the fourth stirring is 5% to 10%.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the conductive agent and the binder are first stirred to obtain a dry mixture, and the first stirring makes the two mechanically riveted to form a tight entanglement; then the dry mixture is mixed with the solvent for a second stirring to obtain a primary slurry, and the second stirring helps the binder and the conductive agent to be evenly dispersed in the solvent; in the third stirring, the positive electrode active material is mixed with the primary slurry to obtain a secondary slurry, and the third stirring helps the positive electrode active material to be evenly dispersed in the primary slurry system, and can be evenly coated and entangled by the conductive agent and the binder; in the fourth stirring, the secondary slurry is mixed with the solvent to obtain a uniform and stable positive electrode slurry that meets the processing performance and electrical properties.
  • the mass ratio of the solvent used in the second stirring is 35% to 40%, and the mass ratio of the solvent used in the fourth stirring is 5% to 10%. Based on the total mass of the positive electrode active material used in the third stirring, the viscosity of the slurry can be effectively reduced, and the viscosity of the slurry can be further adjusted to prevent the viscosity of the slurry from being too high after standing for 24 hours, which affects the subsequent coating work.
  • the preparation method of the positive electrode slurry in the prior art has poor compatibility and cannot adapt to the difference in the weight average molecular weight of the binder in the slurry. Therefore, a very high precision requirement is put forward for the material.
  • the present application reduces the shipping viscosity and the viscosity of the positive electrode slurry after standing for 24 hours by adjusting the step-by-step slurry mixing and stirring parameters, alleviates the gelation phenomenon of the positive electrode slurry, and makes the slurry with a high weight average molecular weight binder still have a low shipping viscosity and viscosity and anti-coagulation after standing for 24 hours, thereby improving the universality of the preparation method.
  • the preparation method of the present application is not only applicable to binders with low weight average molecular weight, but also to binders with high weight average molecular weight, which can effectively alleviate the gelation phenomenon of different slurries, help to improve production efficiency, and broaden the process window of slurry coating.
  • the binder comprises at least one polyvinylidene fluoride having a weight average molecular weight of 400,000 to 1.8 million.
  • the weight average molecular weight of the polyvinylidene fluoride can be selected from any one of 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000, 1,050,000, 1,100,000, 1,150,000, 1,200,000, 1,250,000, 1,300,000, 1,350,000, 1,400,000, 1,450,000, 1,500,000, 1,550,000, 1,600,000, 1,650,000, 1,700,000, 1,750,000, and 1,800,000.
  • weight average molecular weight refers to the statistical average molecular weight of a polymer by mass, the molecular weight averaged over a unit weight.
  • the slurry mixing process in the prior art is difficult to apply to high weight average molecular weight binders.
  • the prepared slurry has a high shipping viscosity, which is difficult to meet the coating requirements, and the slurry will have serious gelation.
  • the preparation method disclosed in the present application can be applied to binders with a weight average molecular weight of up to 1.8 million, so that the slurry still has a low shipping viscosity and a viscosity after standing for 24 hours, and the slurry has good anti-gel properties, which can meet the use requirements of the new generation of high molecular weight binders.
  • the binder comprises at least two polyvinylidene fluoride with a weight average molecular weight difference of no more than 1.8 million.
  • the weight average molecular weight difference of two or more polyvinylidene fluoride can be selected as any one of 100,000, 200,000, 300,000, 400,000, 500,000, 600,000, 700,000, 800,000, 900,000, 1 million, 1.1 million, 1.2 million, 1.3 million, 1.4 million, 1.5 million, 1.6 million, 1.7 million, and 1.8 million.
  • the positive electrode slurry prepared by the method of the present application can effectively exert the characteristics of polyvinylidene fluoride binders of different molecular weights, and through the mutual coordination of large and small segments and steric hindrance, the slurry has a good gel state, and the slurry has a low shipping viscosity and a viscosity after standing for 24 hours.
  • the preparation method has a wider universality.
  • the rotation speed of the first stirring is 0.
  • rotational speed refers to the speed at which the agitator rotates about its own axis.
  • the stirring device is a planetary mixer.
  • the working principle of the planetary mixer is that after the mixer is started, the planetary frame rotates, driving the stirring shaft in the box to rotate, and the stirring shaft rotates at high speed while revolving around the axis of the barrel, so that the material is subjected to strong shearing and kneading. It can be understood that the preparation method provided in this application is applicable to any type of planetary mixer.
  • Controlling the rotation speed of the first stirring to 0 reduces the shear force of the first stirring, reduces the risk of excessive crushing of the conductive agent and the binder, ensures that the conductive agent and the binder have a certain particle size and specific surface area, improves the dispersion effect of the conductive agent and the binder, helps to reduce the viscosity of the slurry at delivery and the viscosity after standing for 24 hours, slows down the gelation of the slurry, and improves the stability of the slurry.
  • the stirring time of the first stirring is 15 minutes to 30 minutes. In some embodiments, the stirring time of the first stirring can be any one of 15 minutes, 20 minutes, 25 minutes, and 30 minutes.
  • the stirring time of the first stirring is too short, the conductive agent and the binder cannot be effectively mixed, and the viscosity of the slurry when shipped and the viscosity after standing for 24 hours are too large to meet production needs. If the stirring time of the first stirring is too long, the viscosity of the slurry when shipped, the viscosity of the slurry after standing for 24 hours, and the gel phenomenon of the slurry cannot be significantly improved. Instead, the long stirring time will lead to energy waste and reduce production efficiency.
  • the stirring time of the first stirring in the appropriate range makes the slurry have low shipping viscosity and viscosity after standing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the first stirring in the appropriate range can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours and the gelation phenomenon of the slurry.
  • the revolution speed of the first stirring is 10 rpm to 20 rpm. In some embodiments, the revolution speed of the first stirring can be any one of 10 rpm, 15 rpm, and 20 rpm.
  • bital speed refers to the speed at which the agitator rotates around the vessel containing the material.
  • the rotation speed of the first stirring is too low, the conductive agent and the binder cannot be effectively mixed, and the viscosity of the slurry when shipped and the viscosity after standing for 24 hours are too high, which cannot meet the production needs; if the rotation speed of the first stirring is too high, without significantly improving the viscosity of the slurry when shipped, the viscosity of the slurry after standing for 24 hours, and the gel phenomenon of the slurry, the stirring speed is too high, which will lead to an increase in the power of the agitator and cause energy waste.
  • the revolution speed of the first stirring in the appropriate range makes the slurry have low shipping viscosity and viscosity after standing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • the revolution speed of the first stirring in the appropriate range can be controlled to be 10 rpm to 20 rpm without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gel phenomenon of the slurry, thereby reducing the power of the stirrer, saving energy, and taking into account both the quality and cost of the slurry.
  • the stirring time of the second stirring is 50 minutes to 80 minutes. In some embodiments, the stirring time of the second stirring can be any one of 50 minutes, 60 minutes, 70 minutes, and 80 minutes.
  • the second stirring time is too short, the conductive agent and the binder cannot be effectively dispersed in the solvent, and the slurry's shipping viscosity and viscosity after standing for 24 hours are too large, which is not conducive to the stability of the slurry; if the second stirring time is too long, without significantly improving the slurry's shipping viscosity, the slurry's viscosity after standing for 24 hours, and the gelation phenomenon of the slurry, the long stirring time will lead to energy waste and reduce production efficiency.
  • the stirring time of the second stirring within an appropriate range makes the slurry have low shipping viscosity and viscosity after standing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the second stirring within an appropriate range can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours and the gel state of the slurry.
  • the revolution speed of the second stirring is 15 rpm to 30 rpm. In some embodiments, the revolution speed of the second stirring can be any one of 15 rpm, 20 rpm, 25 rpm, and 30 rpm.
  • the rotation speed of the second stirring is too low, the conductive agent and the binder cannot be effectively dispersed in the solvent, the viscosity of the positive electrode slurry at delivery and after standing for 24 hours are too high to meet actual needs, and the slurry is prone to gelation; if the rotation speed of the second stirring is too high, the slurry is prone to gelation.
  • the revolution speed of the second stirring in a suitable range can slow down the gelation of the slurry, improve the stability of the slurry, and widen the process window.
  • the slurry has a low shipping viscosity and a viscosity after standing for 24 hours, so that the slurry has good coating performance and processing performance.
  • the second stirring rotation speed is 800 rpm to 1300 rpm. In some embodiments, the second stirring rotation speed can be selected from any one of 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm, and 1300 rpm.
  • the rotation speed of the second stirring device within a suitable range can reduce the viscosity of the slurry when it is shipped and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • the stirring time of the third stirring is 100 minutes to 130 minutes. In some embodiments, the stirring time of the third stirring can be any one of 100 minutes, 110 minutes, 120 minutes, and 130 minutes.
  • the stirring time of the third stirring is too short, the positive electrode active material cannot be effectively dispersed in the primary slurry, and the slurry's shipping viscosity and viscosity after standing for 24 hours are too large to meet production needs. If the stirring time of the third stirring is too long, without significantly improving the slurry's shipping viscosity, viscosity of the slurry after standing for 24 hours, and gelation of the slurry, the long stirring time will lead to energy waste and reduced production efficiency.
  • the stirring time of the third stirring within an appropriate range makes the slurry have low shipping viscosity and viscosity after standing for 24 hours, so that the slurry has good coating performance, processing performance and stability.
  • controlling the stirring time of the third stirring within an appropriate range can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours and the gel phenomenon of the slurry.
  • the revolution speed of the third stirring is 20 rpm to 40 rpm. In some embodiments, the revolution speed of the third stirring can be any one of 20 rpm, 30 rpm, and 40 rpm.
  • the rotation speed of the third stirring is too low, the positive electrode active material cannot be effectively dispersed in the primary slurry, and the viscosity of the slurry at delivery and after standing for 24 hours is too high to meet production needs; if the rotation speed of the third stirring is too high, the positive electrode active material will be easily broken, causing the slurry to easily settle.
  • the revolution speed of the third stirring device within a suitable range can reduce the viscosity of the slurry when it is shipped and the viscosity after standing for 24 hours, thereby improving the coating property and processability of the slurry.
  • the rotation speed of the third stirring is 1000 rpm to 1300 rpm. In some embodiments, the rotation speed of the third stirring can be selected from any one of 1000 rpm, 1100 rpm, 1200 rpm, and 1300 rpm.
  • the rotation speed of the third stirring is too low, the positive electrode active material cannot be effectively dispersed in the primary slurry, and the viscosity of the slurry at delivery and after standing for 24 hours is too large to meet production needs; if the rotation speed of the third stirring is too high, the positive electrode active material will be easily broken, causing the slurry to easily settle.
  • the rotation speed of the third stirring device within a suitable range can reduce the viscosity of the slurry when it is shipped and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • the stirring time of the fourth stirring is 30 minutes to 50 minutes. In some embodiments, the stirring time of the fourth stirring can be any one of 30 minutes, 40 minutes, and 50 minutes.
  • the stirring time of the fourth stirring is too short, the solvent cannot be effectively dispersed in the secondary slurry, and the solvent cannot effectively adjust the shipping viscosity of the slurry.
  • the shipping viscosity of the slurry and the viscosity after standing for 24 hours are too large to meet production needs.
  • the slurry is prone to gelling, which is not conducive to the stability of the slurry. If the stirring time of the fourth stirring is too long, it will lead to waste of energy and reduce production efficiency.
  • the stirring time of the fourth stirring in the appropriate range is helpful to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, slow down the gelation phenomenon of the slurry, improve the stability of the slurry, and widen the process window.
  • the revolution speed of the fourth stirring is 20 rpm to 40 rpm. In some embodiments, the revolution speed of the fourth stirring can be any one of 20 rpm, 30 rpm, and 40 rpm.
  • the rotation speed of the fourth stirring is too low, the solvent cannot be effectively dispersed in the secondary slurry, and the solvent cannot effectively adjust the shipping viscosity of the slurry.
  • the shipping viscosity of the slurry and the viscosity after standing for 24 hours are too large to meet production needs.
  • the rotation speed of the fourth stirring is too high, the positive electrode active material and conductive agent in the slurry are excessively stirred and easily broken, causing the slurry to easily settle.
  • the revolution speed of the fourth stirring device within a suitable range is helpful to reduce the viscosity of the slurry when it is shipped and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, and make the slurry have good anti-gel properties.
  • the fourth stirring rotation speed is 1000 rpm to 1300 rpm. In some embodiments, the fourth stirring rotation speed can be any one of 1000 rpm, 1100 rpm, 1200 rpm, and 1300 rpm.
  • the rotation speed of the fourth stirring is too low, the solvent cannot be effectively dispersed in the secondary slurry, and the solvent cannot effectively adjust the shipping viscosity of the slurry.
  • the shipping viscosity of the slurry and the viscosity after standing for 24 hours are too large to meet production needs.
  • the rotation speed of the fourth stirring is too high, the positive electrode active material and conductive agent in the slurry are excessively stirred and easily broken, causing the slurry to easily settle.
  • the rotation speed of the fourth stirring in a suitable range is helpful to reduce the viscosity of the slurry when it is shipped and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, and make the slurry have good anti-gel properties.
  • the mass of the positive electrode active material is 900 kg to 1300 kg. In some embodiments, the mass of the positive electrode active material can be selected as any one of 900 kg, 1000 kg, 1100 kg, 1200 kg, and 1300 kg.
  • the preparation method is suitable for mass production of slurry, can meet the needs of large-scale production of slurry, and improve production efficiency.
  • the mass ratio of the positive electrode active material, the binder, and the conductive agent is (95-98.5): (1-3): (0.5-1). In some embodiments, in the positive electrode slurry, the mass ratio of the positive electrode active material, the binder, and the conductive agent can be any one of 96.3:3:0.7, 96:3:1, 97:2:1, and 98:1:1.
  • the positive electrode slurry within the above range has good processing performance and also enables the formed positive electrode plate to have excellent electrochemical performance.
  • the solvent used in the second stirring and the solvent used in the fourth stirring can be selected from one or more of N-methyl-2-pyrrolidone, N,N-dimethylpropionamide, N,N-diethylpropionamide, N,N-dipropylpropionamide, N,N-dibutylpropionamide, N,N-dimethylethylpropionamide and 3-butoxy-N-methylpropionamide.
  • the above solvents have good solubility for a variety of binders, and can effectively disperse various materials such as binders, positive electrode active materials, and conductive agents, which helps to improve the coating quality of the slurry.
  • the positive electrode active material is one or more of lithium iron phosphate, lithium cobalt oxide, lithium titanate, and lithium nickel cobalt manganese oxide.
  • the positive electrode active material enables the battery to have a high energy density, which is beneficial to improving the cycle performance of the battery.
  • the present application provides a positive electrode slurry, wherein the solid content of the positive electrode slurry is 65% to 70%, the initial viscosity of the positive electrode slurry is 1000 to 35000 mPa ⁇ s, and after the positive electrode slurry is left to stand for 24 hours, the viscosity of the positive electrode slurry does not exceed 50000 mPa ⁇ s.
  • the positive electrode slurry has good processing performance and storage performance, and can improve production efficiency and broaden the coating process window.
  • the positive electrode slurry is prepared by the preparation method in any embodiment of the present application.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, and the positive electrode film layer is prepared from a slurry prepared by the preparation method in any embodiment of the present application.
  • the positive electrode current collector has two surfaces opposite to each other in its 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 may be used.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: 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 conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may also optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-tetrafluoroethylene-propylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and the solvent (such as N-methyl-2-pyrrolidone), are used to prepare the positive electrode slurry by the preparation method of the positive electrode slurry in any embodiment of the present application, the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • the components for preparing the positive electrode sheet such as the positive electrode active material, the conductive agent, the binder and the solvent (such as N-methyl-2-pyrrolidone)
  • the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil copper foil may 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 substrate.
  • the composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative electrode active material may adopt the negative electrode active material for the battery known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • a conductive agent which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays the role of conducting ions between the positive electrode and the negative electrode.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the secondary battery further includes a separator.
  • the present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be the same or different, without particular limitation.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer package of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer package of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • FIG1 is a secondary battery 5 of a square structure as an example.
  • the outer package may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in 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 may be assembled into a battery module.
  • the number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • FIG3 is a battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module 4 may further include a housing having a housing space, and the plurality of secondary batteries 5 are housed in the housing space.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • FIG4 and FIG5 are battery packs 1 as an example.
  • 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 body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 to form a closed space for accommodating the battery modules 4.
  • the plurality of 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 in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • FIG6 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • a battery pack or a battery module may be used.
  • a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.
  • weighing raw materials weighing raw materials according to the positive electrode slurry ratio, the mass ratio of positive electrode active material: binder: conductive agent is 96.3:3:0.7, wherein the positive electrode active material is lithium iron phosphate, the mass of lithium iron phosphate weighed is 900 kg, the binder is polyvinylidene fluoride with a weight average molecular weight of 1.2 million, and the conductive agent is conductive carbon black;
  • First stirring the conductive agent and the binder are mixed and first stirred for 20 minutes at a revolution speed of 20 rpm and a rotation speed of 0 to obtain a dry mixture;
  • NMP N-methyl-2-pyrrolidone solution
  • Third stirring adding the positive electrode active material to the primary slurry and stirring thoroughly, wherein the revolution speed is 30 rpm, the rotation speed is 1200 rpm, and the stirring time is 110 minutes to obtain the secondary slurry.
  • Fourth stirring add NMP solution with a mass of 10% of the mass of the positive electrode active material and continue stirring to adjust the viscosity, wherein the revolution speed is 25 rpm, the rotation speed is 1200 rpm, and the stirring time is 30 minutes to obtain the positive electrode slurry.
  • the method is basically the same as Example 1, except that the mass fraction of the solvent in the second stirring and the fourth stirring is adjusted. For specific parameters, see Table 1.
  • Example 2 It is basically the same as Example 1, except that the weight average molecular weight of the polyvinylidene fluoride binder is adjusted. For specific parameters, see Table 1.
  • Example 7 It is basically the same as Example 1, except that a plurality of binders with different weight average molecular weights are added, and the specific parameters are shown in Table 1.
  • the mass ratio of the first polyvinylidene fluoride to the second polyvinylidene fluoride is 2:1
  • Example 10 the mass ratio of the first polyvinylidene fluoride, the second polyvinylidene fluoride and the third polyvinylidene fluoride is 3:2:1.
  • the method is basically the same as Example 1, except that the stirring parameters are adjusted. For specific parameters, see Table 1.
  • weighing raw materials weighing raw materials according to the positive electrode slurry ratio, the mass ratio of positive electrode active material: binder: conductive agent is 96.3:3:0.7, wherein the positive electrode active material is lithium iron phosphate, the mass of lithium iron phosphate weighed is 900 kg, the binder is polyvinylidene fluoride with a weight average molecular weight of 1.2 million, and the conductive agent is conductive carbon black;
  • NMP N-methyl-2-pyrrolidone solution
  • the positive electrode active material was added to the primary slurry and stirred sufficiently, wherein the revolution speed was 30 rpm, the rotation speed was 1200 rpm, and the stirring time was 110 minutes to obtain a secondary slurry.
  • the method is basically the same as Example 1, except that the mass fraction of the solvent in the second stirring and the fourth stirring is adjusted. For specific parameters, see Table 1.
  • the prepared positive electrode slurry was placed for 10 minutes before shipment.
  • the viscosity value first measured by Dveslvtjo rotary viscosity tester (BROOKFIELD) was recorded as the shipping viscosity, wherein the test conditions were: 25°C, rotation speed 12 rpm, 64 rotor was used to measure the slurry viscosity not less than 2000 mPa ⁇ s, and 62 rotor was used to measure the slurry viscosity less than 2000 mPa ⁇ s. The measurement was repeated three times and the average value was taken.
  • the viscosity of the slurry was retested, and the viscosity value measured by Dveslvtjo rotary viscosity tester (BROOKFIELD) was recorded as the 24-hour viscosity, wherein the test conditions were: 25°C, rotation speed 12 rpm, 64 rotor was used to measure the viscosity of the slurry not less than 2000 mPa ⁇ s, and 62 rotor was used to measure the viscosity of the slurry less than 2000 mPa ⁇ s. The parallel measurements were performed three times and the average value was taken.
  • a steel ruler is used to pick up the slurry in the beaker, and the slurry is judged according to the flow state of the slurry to determine whether it is non-gel, slightly gelled, moderately gelled, or severely gelled.
  • Slight gel state the slurry flows naturally and continuously, but the fluid is thin, and the slurry is basically spread evenly on the surface of the steel ruler, with slight small pieces;
  • Moderate gel state the slurry drips naturally and intermittently; it does not flow continuously, the slurry cannot be spread evenly on the surface of the steel ruler, and there are obvious block agglomerations;
  • Severe gel state The slurry cannot flow down in a stream, falls off in lumps or remains directly on the steel ruler and cannot flow down.
  • the positive electrode slurries of the embodiments and comparative examples were prepared according to the above method, and various parameters were measured. The results are shown in Table 1 below.
  • the positive electrode slurries in Examples 1 to 50 are all prepared by the slurry preparation method disclosed in the present application, including first stirring, second stirring, third stirring and fourth stirring; in the first stirring, the conductive agent and the binder are mixed and stirred to prepare a dry mixture; in the second stirring, the solvent and the dry mixture are mixed and stirred to prepare a primary slurry; in the third stirring, the positive electrode active material and the primary slurry are mixed and stirred to prepare a secondary slurry; in the fourth stirring, the solvent and the secondary slurry are mixed and stirred to prepare a positive electrode slurry; the solvent used in the second stirring is the same as the solvent used in the fourth stirring, and based on the total mass of the positive electrode active material, the mass ratio of the solvent used in the second stirring is 35% to 40%, and the mass ratio of the solvent used in the fourth stirring is 5% to 10%.
  • the preparation method disclosed in the present application has wide versatility and is applicable to slurries of one or more polyvinylidene fluoride binders with a weight average molecular weight of 400,000 to 1.8 million.
  • the preparation method is universal for low weight average molecular weight polyvinylidene fluoride binders and high weight average molecular weight polyvinylidene fluoride binders, which helps to reduce preparation costs and improve production efficiency.
  • the preparation process in the prior art is difficult to reduce the shipping viscosity of the slurry for a binder with a weight average molecular weight of 1.2 million.
  • the viscosity of the slurry after standing for 24 hours even exceeds the range, and the slurry will have serious gelation.
  • the preparation method disclosed in the present application enables the slurry containing a binder with a weight average molecular weight of up to 1.8 million to still have a low shipping viscosity and a viscosity after standing for 24 hours, and the slurry has good anti-gel properties, which can meet the use requirements of a new generation of high molecular weight binders.
  • the present application is also applicable to a slurry containing at least two polyvinylidene fluoride binders whose weight average molecular weight difference is not greater than 1.8 million.
  • the slurry prepared by the method of the present application has low shipping viscosity and viscosity after standing for 24 hours, and good anti-gelling property. Compared with the preparation method in the prior art, this method has wider universality.
  • Example 1 From the comparison between Example 1 and Examples 11 to 12, it can be seen that controlling the rotation speed of the first stirring to 0 helps to reduce the shipping viscosity of the positive electrode slurry and the viscosity after standing for 24 hours, slows down the gelation phenomenon of the slurry, improves the stability of the slurry, and widens the process window.
  • Example 14 to 15 and Example 13 From the comparison between Example 1, Examples 14 to 15 and Example 13, it can be seen that controlling the stirring time of the first stirring to 15 to 30 minutes can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, and make the slurry have good anti-gel properties. From the comparison between Example 1, Examples 14 to 15 and Example 16, it can be seen that controlling the stirring time of the first stirring to 15 to 30 minutes without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation, reduce costs, and take into account both the quality and efficiency of slurry preparation.
  • Example 1 From the comparison between Example 1, Examples 18 to 19 and Example 17, it can be seen that controlling the revolution speed of the first stirring to 10 rpm to 20 rpm can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, and improve the coating and processability of the slurry. From the comparison between Example 1, Examples 18 to 19 and Example 20, it can be seen that controlling the revolution speed of the first stirring to 10 rpm to 20 rpm without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry can reduce the power of the agitator, save energy, and take into account both the quality and cost of the mixed slurry.
  • Example 1 From the comparison between Example 1, Examples 22-23 and Example 21, it can be seen that controlling the stirring time of the second stirring to 50 minutes to 80 minutes helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improves the coating and processability of the slurry, and makes the slurry have good anti-gel properties. From the comparison between Example 1, Examples 22-23 and Example 24, it can be seen that controlling the second stirring time to 50 minutes to 80 minutes can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation, and reduce costs without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry.
  • Example 1 From the comparison between Example 1, Examples 26 to 27 and Examples 25 and 28, it can be seen that controlling the revolution speed of the second stirring to 15 rpm to 30 rpm helps to reduce the shipping viscosity of the positive electrode slurry and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, and also slow down the gelation phenomenon of the slurry, improve the stability of the slurry, and widen the process window.
  • Example 1 From the comparison between Example 1, Examples 30 to 31 and Example 29, it can be seen that controlling the rotation speed of the second stirring to 800 rpm to 1300 rpm can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • Example 1 From the comparison between Example 1, Examples 33-34 and Example 32, it can be seen that controlling the stirring time of the third stirring to 100 minutes to 130 minutes can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, and improve the coating and processability of the slurry. From the comparison between Example 1, Examples 33-34 and Example 35, it can be seen that controlling the stirring time of the third stirring to 100 minutes to 130 minutes without significantly changing the shipping viscosity of the slurry, the viscosity of the slurry after standing for 24 hours, and the gelation phenomenon of the slurry can reduce the working time of slurry preparation, improve the working efficiency of slurry preparation, and reduce costs.
  • Example 1 From the comparison between Example 1, Examples 37 to 38 and Example 36, it can be seen that controlling the revolution speed of the third stirring to 20 rpm to 40 rpm can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • Example 1 From the comparison between Example 1, Examples 40 to 41 and Example 39, it can be seen that controlling the rotation speed of the third stirring to 1000 rpm to 1300 rpm can reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, thereby improving the coating and processability of the slurry.
  • Example 1 From the comparison between Example 1, Examples 43 to 44 and Example 42, it can be seen that controlling the stirring time of the fourth stirring to 30 minutes to 50 minutes helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improve the coating and processability of the slurry, slow down the gelation phenomenon of the slurry, improve the stability of the slurry, and widen the process window.
  • Example 1 From the comparison between Example 1, Examples 46 to 47 and Example 45, it can be seen that controlling the revolution speed of the fourth stirring to 20 rpm to 40 rpm helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improves the coating and processability of the slurry, and makes the slurry have good anti-gel properties.
  • Example 1 From the comparison between Example 1, Examples 49 to 50 and Example 48, it can be seen that controlling the rotation speed of the third stirring to 1000 rpm to 1300 rpm helps to reduce the shipping viscosity of the slurry and the viscosity after standing for 24 hours, improves the coating and processability of the slurry, and makes the slurry have good anti-gel properties.
  • the slurries of Examples 1 to 50 contain 900kg to 1300kg of positive electrode active materials, indicating that the preparation method is suitable for large-scale production of slurries.
  • the preparation methods disclosed in the prior art currently add less material mass and are only suitable for laboratory preparation of slurries, but are difficult to be applied to industrial production of slurries.
  • the method disclosed in this application overcomes the problems of multiple batches of raw materials, poor dispersibility, and poor precision from laboratory preparation to large-scale mass production, and is conducive to improving the production efficiency of positive electrode slurries.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请提供了一种正极浆料的制备方法、二次电池、电池包和用电装置。该制备方法包括第一搅拌、第二搅拌、第三搅拌和第四搅拌；第一搅拌中，将导电剂与粘结剂混合搅拌，制备干混料；第二搅拌中，将溶剂与干混料混合搅拌，制备初级浆料；第三搅拌中，将正极活性材料与初级浆料混合搅拌，制备二级浆料；第四搅拌中，将溶剂与二级浆料混合搅拌，制备正极浆料；第二搅拌中使用的溶剂与第四搅拌中使用的溶剂相同，基于正极活性材料的总质量计，第二搅拌中使用的溶剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％。

Description

正极浆料的制备方法、二次电池、电池包和用电装置 技术领域
本申请涉及二次电池技术领域，尤其涉及一种二次电池正极浆料的制备方法、二次电池、电池包和用电装置。
背景技术
近年来，随着二次电池的应用范围越来越广泛，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。
电极浆料是成型电极的基础，也是二次电池生产的第一道工序。电极浆料的特性对后续的电极生产、电池性能都有显著的影响。正极浆料主要是由正极活性材料、导电剂、粘结剂和溶剂形成的固-液相混合体系。该体系处于一种亚稳定状态，合浆工艺，也就是浆料的制备方法对浆料的分散性、均匀性、稳定性等性能有着至关重要的影响。现有技术中的合浆工艺常为一步法，将正极浆料中的各组分直接混合搅拌即得，然而一步法的制备方法无法满足不同重均分子量粘结剂的制造需求，合浆工艺通用性差，不利于制造成本的降低。因此，需要开发出一种新的浆料的制备方法，以适用于不同重均分子量的粘结剂。
发明内容
本申请是鉴于上述课题而进行的，其目的在于，提供一种二次电池正极浆料的制备方法，以适用于不同重均分子量的粘结剂，提高浆料的涂布性、加工性。
为了达到上述目的，本申请提供了一种正极浆料的制备方法，包括第一搅拌、第二搅拌、第三搅拌和第四搅拌；第一搅拌中，将导电剂与粘结剂混合搅拌，制备干混料；第二搅拌中，将溶剂与干混料混 合搅拌，制备初级浆料；第三搅拌中，将正极活性材料与初级浆料混合搅拌，制备二级浆料；第四搅拌中，将溶剂与所述二级浆料混合搅拌，制备正极浆料；第二搅拌中使用的溶剂与所述第四搅拌中使用的溶剂相同，基于正极活性材料的总质量计，第二搅拌中使用的溶剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％。
由此，本申请公开的正极浆料的制备方法相比于现有的正极浆料的制备方法更具有广泛的通用性，适用于包含不同重均分子量粘结剂的浆料，相比于现有的制备方法，本申请通过分步合浆，降低了正极浆料的出货粘度，缓解了正极浆料的凝胶现象，提高了制备方法对于大分子量的粘结剂的适用性，制备方法具有更广泛的普适性，拓展了正极浆料涂布的工艺窗口，提高了正极浆料的加工性能。
在任意实施方式中，粘结剂包含至少一种重均分子量为40万～180万的聚偏氟乙烯。
本申请公开的制备方法对低分子量聚偏氟乙烯粘结剂和高分子量聚偏氟乙烯粘结剂具有普适性，能够有效缓解不同浆料的凝胶现象，有助于提高生产效率，拓宽浆料的涂覆窗口。本申请公开的制备方法能够适用于重均分子量高达180万的粘结剂，使得包含高重均分子量粘结剂的浆料依然具有低的出货粘度和抗凝胶性，能够满足新一代粘结剂的使用需求。
在任意实施方式中，粘结剂至少包含两种重均分子量的差值不大于180万的聚偏氟乙烯。
申请人意外地发现本申请公开的制备方法可以有效地适应包含多种重均分子量粘结剂的正极浆料。采用本申请的方法制备的正极浆料能够有效发挥不同分子量的聚偏氟乙烯粘结剂的特性，通过大小链段的相互配合和空间位阻作用，使得浆料具有良好的凝胶状态，同时浆料具有低的出货粘度和静置24小时后的粘度。
在任意实施方式中，第一搅拌的自转速度为0。
控制第一搅拌的自转速度为0，降低第一搅拌的剪切力，降低导电剂和粘结剂被过分打碎的可能性，保证导电剂和粘结剂具有一定的颗粒度和比表面积，有助于提高导电剂和粘结剂的分散效果，降低浆 料的出货粘度和静置24小时后的粘度，减缓浆料的凝胶现象，提高浆料的稳定性。
在任意实施方式中，第一搅拌的搅拌时间为15分钟～30分钟。合适范围的第一搅拌的搅拌时间，使得浆料具有低的出货粘度和静置储存24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围的第一搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在任意实施方式中，第一搅拌的公转速度为10转/分钟～20转/分钟。合适范围的第一搅拌的公转速度，使得浆料具有低的出货粘度和静置存储24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围内的第一搅拌的公转速度，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，控制第一搅拌的公转速度为10转/分钟～20转/分钟，降低搅拌器的功率，节约能源，能够兼顾合浆质量和成本。
在任意实施方式中，第二搅拌的搅拌时间为50～80分钟。合适范围的第二搅拌的搅拌时间，使得浆料具有低的出货粘度和静置存储24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围的第二搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在任意实施方式中，第二搅拌的公转速度为15转/分钟～30转/分钟。合适范围的第二搅拌的公转速度，可以减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口，同时使得浆料具有低的出货粘度和静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能。
在任意实施方式中，第二搅拌的自转速度800转/分钟～1300转/分钟。合适范围的第二搅拌的自转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在任意实施方式中，第三搅拌的搅拌时间为100分钟～130分钟。 合适范围的第三搅拌的搅拌时间，使得浆料具有低的出货粘度和静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围的第三搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在任意实施方式中，第三搅拌的公转速度为20转/分钟～40转/分钟。合适范围的第三搅拌的公转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在任意实施方式中，第三搅拌的自转速度为1000转/分钟～1300转/分钟。合适范围的第三搅拌的自转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在任意实施方式中，第四搅拌的搅拌时间为30分钟～50分钟。合适范围的第四搅拌的搅拌时间，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口。
在任意实施方式中，第四搅拌的公转速度为20转/分钟～40转/分钟。合适范围的第四搅拌的公转速度，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，并且使得浆料具有良好的抗凝胶性。
在任意实施方式中，第四搅拌的自转速度为1000转/分钟～1300转/分钟。合适范围的第四搅拌的自转速度，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，且使得浆料具有良好的抗凝胶性。
在任意实施方式中，正极活性材料质量为900kg～1300kg。该制备方法适用于浆料的工业量产，有效克服从实验室生产到工业化量产中遇到的原材料批次稳定性差、精度差的问题，利于提高生产效率。
在任意实施方式中，正极浆料中，正极活性材料、粘结剂、导电剂的质量比为(95～98.5)∶(1～3)∶(0.5～1)。上述范围内的正极浆料既有良好的加工性能，又使得成型后的正极极片具有优异的电化学性能。
在任意实施方式中，正极活性材料为磷酸铁锂、钴酸锂、钛酸锂、 镍钴锰酸锂中的一种或几种。上述正极活性材料，使得电池具有高的能量密度，有利于提高电池的循环性能。
本申请的第二方面还提供一种正极浆料，正极浆料的固含量为65％～70％，所述正极浆料的初始粘度为1000～35000mPa·s，且所述正极浆料在静置24小时后，所述正极浆料的粘度不超过50000mPa·s。
该正极浆料具有良好的加工性能和存储性能，能够提高生产效率、拓宽涂布工艺窗口。
在任意实施方式中，该正极浆料是由第一方面所述的制备方法制备的。
本申请的第三方面提供一种二次电池，包括正极极片、隔离膜、负极极片以及电解液，所述正极极片由第一方面所述的制备方法制备的正极浆料制备而得。该正极极片具有高的品质和生产效率。
在任意实施方式中，二次电池为锂离子电池、钠离子电池、镁离子电池、钾离子电池中的任意一种。
本申请的第四方面还提供一种电池模块，包括本申请第三方面所述的二次电池。
本申请的第五方面提供一种电池包，包括本申请第三方面所述的二次电池或本申请的第四方面的电池模块。
本申请的第六方面提供一种用电装置，包括选自本申请的第三方面的二次电池、本申请的第四方面的电池模块或本申请的第五方面的电池包中的至少一种。
附图说明
图1是本申请一实施方式的二次电池的示意图；
图2是图1所示的本申请一实施方式的二次电池的分解图；
图3是本申请一实施方式的电池模块的示意图；
图4是本申请一实施方式的电池包的示意图；
图5是图4所示的本申请一实施方式的电池包的分解图；
图6是本申请一实施方式的二次电池用作电源的用电装置的示 意图。
附图标记说明：
1电池包；2上箱体；3下箱体；4电池模块；5二次电池；51壳体；52电极组件；53盖板。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的正极活性材料及其制造方法、正极极片、二次电池、电池模块、电池包和电学装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
正极浆料主要是由正极活性材料、导电剂、粘结剂和溶剂形成的固-液相混合体系。为了提高体系中不同组分分布的均匀性，常通过搅拌、球磨、超声等工艺进行合浆。然而，现有技术中的合浆工艺通常只适用于固定组分的浆料体系，通用性差，浆料中各组分的物性发生变化后，合浆工艺往往需要调整。例如，现有技术中的合浆工艺不能适用于大分子量粘结剂，使用不同分子量的粘结剂的浆料采用相同的现有技术中的合浆工艺制备后性能差异性大，浆料出货粘度大，难以满足后续极片的生产需求。
[正极浆料的制备]
基于此，本申请提出了一种正极浆料的制备方法，包括第一搅拌、第二搅拌、第三搅拌和第四搅拌；第一搅拌中，将导电剂与粘结剂混合搅拌，制备干混料；第二搅拌中，将溶剂与干混料混合搅拌，制备初级浆料；第三搅拌中，将正极活性材料与初级浆料混合搅拌，制备二级浆料；第四搅拌中，将溶剂与二级浆料混合搅拌，制备正极浆料；第二搅拌中使用的溶剂与第四搅拌中使用的溶剂相同，基于所述正极 活性材料的总质量计，第二搅拌中使用的溶剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％。
在一些实施方式中，导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在该制备方法中，先将导电剂与粘结剂进行第一搅拌得到干混料，第一搅拌使两者机械铆合，形成紧密缠结；再将干混料与溶剂混合进行第二搅拌得到初级浆料，第二搅拌有助于粘结剂和导电剂均匀的分散于溶剂中；第三搅拌中，将正极活性材料与初级浆料混合得到二级浆料，第三搅拌有助于正极活性材料在初级浆料体系中分散均匀，且能够被导电剂及粘结剂均匀包覆缠结；在第四搅拌中，将二级浆料与溶剂混合，制得均匀稳定，满足加工性能及电性能的正极浆料。第二搅拌中使用的溶剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％，基于第三搅拌中使用的正极活性材料的总质量计，能够有效降低浆料的出货粘度，进一步调节出货浆料的粘度，防止浆料的出货粘度和静置24小时后的粘度过高，影响后续的涂布工作。
若第二搅拌或第四搅拌中加入的溶剂质量过多或过少，都无法有效降低浆料的静置24小时后的粘度，无法达到减缓浆料凝胶的目的。
现有技术中的正极浆料的制备方法兼容性差，无法适应浆料中粘结剂重均分子量的差异，因此，对于材料提出了很高的精度需求。本申请通过分步合浆和搅拌参数的搭配调控，降低了正极浆料的出货粘度和静置24小时的粘度，缓解了正极浆料的凝胶现象，使得具有高重均分子量粘结剂的浆料依然具有低的出货粘度和静置24小时后的粘度和抗凝性，提高制备方法的普适性。本申请的制备方法不仅适用于低重均分子量的粘结剂，也能适用于高重均分子量的粘结剂，能够有效缓解不同浆料的凝胶现象，有助于提高生产效率、拓宽浆料涂覆的工艺窗口。
在一些实施方式中，粘结剂包含至少一种重均分子量为40万～180万的聚偏氟乙烯。在一些实施方式中，聚偏氟乙烯的重均分子量可选为40万、45万、50万、55万、60万、65万、70万、75万、80万、85万、90万、95万、100万、105万、110万、115万、120万、 125万、130万、135万、140万、145万、150万、155万、160万、165万、170万、175万、180万中的任意一种。
在本文中，术语“重均分子量”是指聚合物按质量的统计平均分子量，在单位重量上平均得到的分子量。
现有技术中的合浆工艺难以适用于高重均分子量的粘结剂，制备出的浆料具有高的出货粘度，难以满足涂布需求，而且浆料会出现严重的凝胶现象。而本申请公开的制备方法能够适用于重均分子量高达180万的粘结剂，使得浆料依然具有低的出货粘度和静置24小时后的粘度，并且浆料具有良好的抗凝胶性，能够满足新一代高分子量粘结剂的使用需求。
在一些实施方式中，粘结剂至少包含两种重均分子量的差值不大于180万的聚偏氟乙烯。在一些实施方式中，两种或两种以上的聚偏氟乙烯的重均分子量的差值可选为10万、20万、30万、40万、50万、60万、70万、80万、90万、100万、110万、120万、130万、140万、150万、160万、170万、180万中的任意一种。
申请人意外地发现本申请公开的制备方法可以有效地适应包含多种重均分子量粘结剂的正极浆料。采用本申请的方法制备的正极浆料能够有效发挥不同分子量的聚偏氟乙烯粘结剂的特性，通过大小链段的相互配合和空间位阻作用，使得浆料具有良好的凝胶状态，同时浆料具有低的出货粘度和静置24小时后的粘度，该制备方法具有更为广泛的普适性。
在一些实施方式中，第一搅拌的自转速度为0。
在本文中，术语“自转速度”是指搅拌器绕自身轴线转动的速度。
在一些实施方式中，搅拌装置为行星搅拌机。行星搅拌机的工作原理是搅拌机启动后，行星架转动，带动箱内搅拌轴转动，在围绕料筒轴线公转的同时高速自转，从而物料受到强烈的剪切、捏合作用。可以理解，本申请提供的制备方法适用于任何类型的行星搅拌机。
控制第一搅拌的自转速度为0，降低第一搅拌的剪切力，降低导电剂和粘结剂被过分打碎的风险，保证导电剂和粘结剂具有一定的颗粒度和比表面积，提高导电剂和粘结剂的分散效果，有助于降低浆料 的出货粘度和静置24小时后的粘度，减缓浆料的凝胶现象，提高浆料的稳定性。
在一些实施方式中，第一搅拌的搅拌时间为15分钟～30分钟。在一些实施方式中，第一搅拌的搅拌时间可选为15分钟、20分钟、25分钟、30分钟中的任意一种。
若第一搅拌的搅拌时间过短，导电剂与粘结剂不能有效的混合，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第一搅拌的搅拌时间过长，在不能明显改善浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，搅拌时间过长反而导致能源的浪费、降低生产效率。
合适范围的第一搅拌的搅拌时间，使得浆料具有低的出货粘度、静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围的第一搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在一些实施方式中，第一搅拌的公转速度为10转/分钟～20转/分钟。在一些实施方式中，第一搅拌的公转速度可选为10转/分钟、15转/分钟、20转/分钟中的任意一种。
在本文中，术语“公转速度”是指搅拌器绕装载物料的釜体转动的速度。
若第一搅拌的公转速度过小，导电剂与粘结剂不能有效的混合，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第一搅拌的公转速度过大，在不能明显改善浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，搅拌速度过大反而导致搅拌器功率提高，造成能源的浪费。
合适范围的第一搅拌的公转速度，使得浆料具有低的出货粘度、静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性。同时控制合适范围内的第一搅拌的公转速度，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象 的情况下，控制第一搅拌的公转速度为10转/分钟～20转/分钟，降低搅拌器的功率，节约能源，能够兼顾合浆质量和成本。
在一些实施方式中，第二搅拌的搅拌时间为50分钟～80分钟。在一些实施方式中，第二搅拌的搅拌时间可选为50分钟、60分钟、70分钟、80分钟中的任意一种。
若第二搅拌的搅拌时间过短，导电剂与粘结剂不能有效的分散于溶剂中，浆料的出货粘度和静置24小时后的粘度过大，不利于浆料的稳定性；若第二搅拌的搅拌时间过长，在不能明显改善浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，搅拌时间过长反而导致能源的浪费、降低生产效率。
合适范围的第二搅拌的搅拌时间，使得浆料具有低的出货粘度、静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性，同时控制合适范围的第二搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶状态的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在一些实施方式中，第二搅拌的公转速度为15转/分钟～30转/分钟。在一些实施方式中，第二搅拌的公转速度可选为15转/分钟、20转/分钟、25转/分钟、30转/分钟中的任意一种。
若第二搅拌的公转速度过小，导电剂与粘结剂不能有效的分散于溶剂中，正极浆料的出货粘度和静置24小时后的粘度过大，无法满足实际需求，另外浆料容易出现凝胶现象；若第二搅拌的公转速度过大，浆料容易出现凝胶现象。
合适范围的第二搅拌的公转速度，可以减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口，同时浆料具有低的出货粘度、静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能。
在一些实施方式中，第二搅拌的自转速度800转/分钟～1300转/分钟。在一些实施方式中，第二搅拌的自转速度可选为800转/分钟、900转/分钟、1000转/分钟、1100转/分钟、1200转/分钟、1300转/分钟中的任意一种。
若第二搅拌的自转速度过低或过高，都会导致导电剂、粘结剂无法在溶剂中得到有效分散，使得浆料的出货粘度过大，无法满足生产需求。
合适范围的第二搅拌的自转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在一些实施方式中，第三搅拌的搅拌时间为100分钟～130分钟。在一些实施方式中，第三搅拌的搅拌时间可选为100分钟、110分钟、120分钟、130分钟中的任意一种。
若第三搅拌的搅拌时间过短，正极活性材料不能有效的分散于初级浆料中，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第三搅拌的搅拌时间过长，在不能明显改善浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，搅拌时间过长反而导致能源的浪费、降低生产效率。
合适范围的第三搅拌的搅拌时间，使得浆料具有低的出货粘度、静置24小时后的粘度，使得浆料具有良好的涂布性能、加工性能和稳定性，同时控制合适范围的第三搅拌的搅拌时间，可以在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
在一些实施方式中，第三搅拌的公转速度为20转/分钟～40转/分钟。在一些实施方式中，第三搅拌的公转速度可选为20转/分钟、30转/分钟、40转/分钟中的任意一种。
若第三搅拌的公转速度过小，正极活性材料不能有效的分散于初级浆料中，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第三搅拌的公转速度过大，会导致正极活性材料容易发生破碎，使得浆料容易沉降。
合适范围的第三搅拌的公转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在一些实施方式中，第三搅拌的自转速度为1000转/分钟～1300转/分钟。在一些实施方式中，第三搅拌的自转速度可选为1000转/分 钟、1100转/分钟、1200转/分钟、1300转/分钟中的任意一种。
若第三搅拌的自转速度过小，正极活性材料不能有效的分散于初级浆料中，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第三搅拌的自转速度过大，会导致正极活性材料容易发生破碎，使得浆料容易沉降。
合适范围的第三搅拌的自转速度，可以降低的浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
在一些实施方式中，第四搅拌的搅拌时间为30分钟～50分钟。在一些实施方式中，第四搅拌的搅拌时间可选为30分钟、40分钟、50分钟中的任意一种。
若第四搅拌的搅拌时间过短，溶剂无法有效的分散在二级浆料中，溶剂无法有效的调节浆料的出货粘度，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要，浆料容易出现凝胶现象，不利于浆料的稳定性；若第四搅拌的搅拌时间过长，导致能源的浪费、降低生产效率。
合适范围的第四搅拌的搅拌时间，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口。
在一些实施方式中，第四搅拌的公转速度为20转/分钟～40转/分钟。在一些实施方式中，第四搅拌的公转速度可选为20转/分钟、30转/分钟、40转/分钟中的任意一种。
若第四搅拌的公转速度过小，溶剂无法有效的分散在二级浆料中，溶剂无法有效的调节浆料的出货粘度，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第四搅拌的公转速度过大，浆料中的正极活性材料、导电剂被过分搅拌，容易发生破碎，使得浆料容易沉降。
合适范围的第四搅拌的公转速度，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，并且使得浆料具有良好的抗凝胶性。
在一些实施方式中，第四搅拌的自转速度为1000转/分钟～1300 转/分钟。在一些实施方式中，第四搅拌的自转速度可选为1000转/分钟、1100转/分钟、1200转/分钟、1300转/分钟中的任意一种。
若第四搅拌的自转速度过小，溶剂无法有效的分散在二级浆料中，溶剂无法有效的调节浆料的出货粘度，浆料的出货粘度和静置24小时后的粘度过大，无法满足生产需要；若第四搅拌的自转速度过大，浆料中的正极活性材料、导电剂被过分搅拌，容易发生破碎，使得浆料容易沉降。
合适范围的第四搅拌的自转速度，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，且使得浆料具有良好的抗凝胶性。
在一些实施方式中，正极活性材料质量为900kg～1300kg。在一些实施方式中，正极活性材料质量可选为900kg、1000kg、1100kg、1200kg、1300kg中的任意一种。
该制备方法适用于浆料的量产，可以满足浆料大规模生产的需要，提高生产效率。
在一些实施方式中，正极浆料中，正极活性材料、粘结剂、导电剂的质量比为(95～98.5)∶(1～3)∶(0.5～1)。在一些实施方式中，正极浆料中，正极活性材料、粘结剂、导电剂的质量比可选为96.3∶3∶0.7、96∶3∶1、97∶2∶1、98∶1∶1中的任意一种。
上述范围内的正极浆料既有良好的加工性能，又使得成型后的正极极片具有优异的电化学性能。
在一些实施方式中，第二搅拌中使用的溶剂和第四搅拌中使用的溶剂可选为N-甲基-2-吡咯烷酮、N,N-二甲基丙酰胺、N,N-二乙基丙酰胺、N,N-二丙基丙酰胺、N,N-二丁基丙酰胺、N,N-二甲基乙基丙酰胺以及3-丁氧基-N-甲基丙酰胺中的一种或多种。
上述溶剂对多种粘结剂都具有良好的溶解性，能够将粘结剂、正极活性材料、导电剂等各种物料有效分散，有助于提高浆料的涂布质量。
在一些实施方式中，正极活性材料为磷酸铁锂、钴酸锂、钛酸锂、镍钴锰酸锂中的一种或几种。
上述正极活性材料，使得电池具有高的能量密度，有利于提高电池的循环性能。
[正极浆料]
本申请提供一种正极浆料，所述正极浆料的固含量为65％～70％，所述正极浆料的初始粘度为1000～35000mPa·s，且所述正极浆料在静置24小时后，所述正极浆料的粘度不超过50000mPa·s。
该正极浆料具有良好的加工性能和存储性能，能够提高生产效率、拓宽涂布工艺窗口。
在一些实施方式中，正极浆料由本申请任意实施方式中的制备方法制备而得。
[正极极片]
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，正极膜层由本申请任意实施方式中的制备方法制备的浆料制备而得。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种， 也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和溶剂(例如N-甲基-2-吡咯烷酮)采用本申请任意实施方式中的正极浆料的制备方法进行正极浆料的制备，将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。
[负极极片]
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
[电解质]
电解质在正极极片和负极极片之间起到传导离子的作用。本申请 对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
[隔离膜]
在一些实施方式中，二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料 壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的二次电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
图3是作为一个示例的电池模块4。参照图3，在电池模块4中，多个二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
图4和图5是作为一个示例的电池包1。参照图4和图5，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
图6是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对二次电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用二次电池作为电源。
实施例
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
一、制备方法
实施例1
1)正极浆料的制备
称取原料：按照正极浆料配比称取原料，正极活性材料∶粘结剂∶导电剂的质量比为96.3∶3∶0.7，其中正极活性材料为磷酸锂铁，称取的磷酸铁锂的质量为900kg，粘结剂为重均分子量为120万的聚偏氟乙烯，导电剂为导电炭黑；
第一搅拌：将导电剂与粘结剂混合，进行第一搅拌，搅拌时间为20分钟，公转速度为20转/分钟，自转速度为0，得到干混料；
第二搅拌：将上述干混料加入到N-甲基-2-吡咯烷酮溶液(NMP)，充分搅拌，其中，NMP溶液的质量为正极活性材料质量的35％，公转速度25转/分钟，自转速度800转/分钟，搅拌时间60分钟，得到初级浆料；
第三搅拌：将正极活性材料加入到初级浆料中充分搅拌，其中公转速度30转/分钟，自转速度1200转/分钟，搅拌时间110分钟，得到二级浆料。
第四搅拌：加入质量为正极活性材料质量的10％的NMP溶液继续搅拌调节粘度，其中公转速度25转/分钟，自转速度1200转/分钟，搅拌时间30分钟，得到正极浆料。
实施例2～3
与实施例1基本相同，区别在于，调整了第二搅拌和第四搅拌中溶剂的质量分数，具体参数参见表1。
实施例4～6
与实施例1基本相同，区别在于，调整了聚偏氟乙烯粘结剂的重均分子量，具体参数参见表1。
实施例7～10
与实施例1基本相同，区别在于，加入多种不同重均分子量的粘结剂，具体参数参见表1。实施例7～9中，第一种聚偏氟乙烯与第二种聚偏氟乙烯的质量比为2∶1，实施例10中，第一种聚偏氟乙烯、第二种聚偏氟乙烯与第三种聚偏氟乙烯的质量比为3∶2∶1。
实施例11～50
与实施例1基本相同，区别在于，调整搅拌参数，具体参数参见表1。
对比例1
称取原料：按照正极浆料配比称取原料，正极活性材料∶粘结剂∶导电剂的质量比为96.3∶3∶0.7，其中正极活性材料为磷酸锂铁，称取的磷酸铁锂的质量为900kg，粘结剂为重均分子量为120万的聚偏氟乙烯，导电剂为导电炭黑；
将粘结剂加入N-甲基-2-吡咯烷酮溶液(NMP)溶剂中，充分搅拌， 其中NMP溶液的质量为正极活性材料质量的35％，公转速度25转/分钟，自转速度800转/分钟，搅拌时间20分钟，得到胶液；
将导电剂加入到胶液中，充分搅拌，搅拌公转速度25转/分钟，自转速度1200转/分钟，搅拌时间40分钟，得到初级浆料；
将正极活性材料加入到初级浆料中充分搅拌，其中公转速度30转/分钟，自转速度1200转/分钟，搅拌时间110分钟，得到次级浆料。
加入质量为正极活性材料质量的10％的NMP溶液继续搅拌调粘，其中公转速度25转/分钟，自转速度1200转/分钟，搅拌时间30分钟，得到正极浆料；
对比例2～3
与对比例1基本相同，区别在于，聚偏氟乙烯的重均分子量分别为40万、80万，具体的参数参见表1。
对比例4～5
与实施例1基本相同，区别在于，调整了第二搅拌和第四搅拌中溶剂的质量分数，具体参数参见表1。
二、浆料性质测试
1、浆料出货的粘度测试
将制得的正极浆料放置10分钟后出货，采用Dveslvtjo旋转粘度测试仪(BROOKFIELD)首次测得的粘度值记为出货粘度，其中，测试条件：25℃，转速12转/分钟，测定不低于2000mPa·s的浆料粘度采用64转子，测定小于2000mPa·s的浆料粘度采用62转子。平行测定三次，取平均值。
2、浆料静置24小时之后的粘度测试
将静置24小时后的浆料重新进行粘度测试，采用Dveslvtjo旋转粘度测试仪(BROOKFIELD)测得的粘度值记为24小时粘度，其中，测试条件：25℃，转速12转/分钟，测定不低于2000mPa·s的浆料粘度采用64转子，测定小于2000mPa·s的浆料粘度采用62转子。平行测定三次，取平均值。
3、浆料静置24小时之后的凝胶状态测试
浆料静置24小时之后，使用钢直尺挑起烧杯中的浆料，根据浆料流动状态判断浆料是否为无凝胶、轻微凝胶、中度凝胶、严重凝胶。
无凝胶状态：浆料自然流动不断流，浆料在钢尺表面平流，无结块；
轻微凝胶状态：浆料自然流动不断流，但流体较细，浆料在钢尺表面基本平摊，有轻微小块；
中度凝胶状态：浆料自然滴落、时断时续；不连续成流，浆料在钢尺表面无法平摊，有明显块状团聚；
严重凝胶状态：浆料无法成流流下，结成块掉落或直接留在钢尺上无法流下。
表1 实施例和对比例中的制备参数以及性能测试
Figure PCTCN2022131506-appb-000001
Figure PCTCN2022131506-appb-000002
Figure PCTCN2022131506-appb-000003
三、各实施例、对比例测试结果分析
按照上述方法分别制备各实施例和对比例的正极浆料，并测量各项参数，结果见下表1。
根据表1的结果可知，实施例1～50中的正极浆料，均是采用本申请公开的浆料制备方法制备的，包括第一搅拌、第二搅拌、第三搅拌和第四搅拌；第一搅拌中，将导电剂与粘结剂混合搅拌，制备干混料；第二搅拌中，将溶剂与干混料混合搅拌，制备初级浆料；第三搅拌中，将正极活性材料与初级浆料混合搅拌，制备二级浆料；第四搅拌中，将溶剂与二级浆料混合搅拌，制备正极浆料；第二搅拌中使用的溶剂与第四搅拌中使用的溶剂相同，基于正极活性材料的总质量计，第二搅拌中使用的溶剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％。
从实施例1～10与对比例1～3的对比可见，本申请公开的制备方法具有广泛的通用性，适用于一种或多种重均分子量在40万～180万的聚偏氟乙烯粘结剂的浆料，该制备方法对于低重均分子量聚偏氟乙烯粘结剂和高重均分子量聚偏氟乙烯粘结剂具有普适性，有助于制备成本的下降、生产效率的提高。
从对比例1可见，现有技术中的制备工艺对于重均分子量为120万的粘结剂就难以降低浆料的出货粘度，静置24小时后的浆料粘度甚至超过量程，浆料会出现严重的凝胶现象。从实施例6可见，本申请公开的制备方法使得包含重均分子量高达180万粘结剂的浆料依然具有低的出货粘度和静置24小时后的粘度，并且浆料具有良好的抗凝胶性，能够满足新一代高分子量粘结剂的使用需求。
从实施例7～10可见，本申请还适用于至少包含两种重均分子量的差值不大于180万的聚偏氟乙烯粘结剂的浆料，采用本申请的方法制备的浆料具有低的出货粘度和静置24小时后的粘度，良好的抗凝胶性。相比于现有技术中的制备方法，该方法具有更为广泛的普适性。
从实施例1～3与对比例4～5对比可见，控制第二搅拌中使用的溶 剂的质量比为35％～40％，第四搅拌中使用的溶剂的质量比为5％～10％，基于正极活性材料的总质量计，有助于降低浆料静置24小时后的粘度，能够有效缓解浆料的凝胶，提高浆料的存储性能，拓宽浆料涂覆的工艺窗口。
从实施例1与实施例11～12对比可见，控制第一搅拌的自转速度为0，有助于降低正极浆料的出货粘度和静置24小时后的粘度，减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口。
从实施例1、实施例14～15与实施例13对比可见，控制第一搅拌的搅拌时间15分钟～30分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，并且使得浆料具有良好的抗凝胶性。从实施例1、实施例14～15与实施例16对比可见，在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，控制第一搅拌的搅拌时间15分钟～30分钟，可以减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本，能够兼顾合浆质量和效率。
从实施例1、实施例18～19与实施例17对比可见，控制第一搅拌的公转速度为10转/分钟～20转/分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，从实施例1、实施例18～19与实施例20对比可见，在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，控制第一搅拌的公转速度为10转/分钟～20转/分钟，降低搅拌器的功率，节约能源，能够兼顾合浆质量和成本。
从实施例1、实施例22～23与实施例21对比可见，控制第二搅拌的搅拌时间为50分钟～80分钟，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，使得浆料具有良好的抗凝胶性。从实施例1、实施例22～23与实施例24对比可见，在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，控制第二搅拌时间为50分钟～80分钟，可以减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
从实施例1、实施例26～27与实施例25、28对比可见，控制第 二搅拌的公转速度为15转/分钟～30转/分钟，有助于降低正极浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，另外可以减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口。
从实施例1、实施例30～31与实施例29对比可见，控制第二搅拌的自转速度800转/分钟～1300转/分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
从实施1、实施例33～34与实施例32对比可见，控制第三搅拌的搅拌时间为100分钟～130分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。从实施例1、实施例33～34与实施例35对比可见，在不明显改变浆料的出货粘度、浆料静置24小时后的粘度、浆料的凝胶现象的情况下，控制第三搅拌的搅拌时间为100分钟～130分钟，可以减少浆料制备的工作时间，提高浆料制备的工作效率，降低成本。
从实施例1、实施例37～38与实施例36对比可见，控制第三搅拌的公转速度为20转/分钟～40转/分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
从实施例1、实施例40～41与实施例39对比可见，控制第三搅拌的自转速度为1000转/分钟～1300转/分钟，可以降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性。
从实施例1、实施例43～44与实施例42对比可见，控制第四搅拌的搅拌时间为30分钟～50分钟，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，减缓浆料的凝胶现象，提高浆料的稳定性，拓宽工艺窗口。
从实施例1、实施例46～47与实施45对比可见，控制第四搅拌的公转速度为20转/分钟～40转/分钟，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，并且使得浆料具有良好的抗凝胶性。
从实施例1、实施例49～50与实施例48对比可见，控制第三搅拌的自转速度为1000转/分钟～1300转/分钟，有助于降低浆料的出货粘度和静置24小时后的粘度，提高浆料的涂布性和加工性，且使 得浆料具有良好的抗凝胶性。
实施例1～50的浆料含有正极活性材料为900kg～1300kg，表明该制备方法适用于浆料的大规模生产。目前现有技术中公开的制备方法加入的材料质量少，仅适用于浆料的实验室制备，难以适用于浆料的工业化生产，本申请公开的方法克服了从实验室制备到大规模量产中原料批次多、分散性差、精度差的问题，利于提高正极浆料的生产效率。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (25)

  1. 一种正极浆料的制备方法，其特征在于，包括第一搅拌、第二搅拌、第三搅拌和第四搅拌；
    所述第一搅拌中，将导电剂与粘结剂混合搅拌，制备干混料；
    所述第二搅拌中，将溶剂与干混料混合搅拌，制备初级浆料；
    所述第三搅拌中，将正极活性材料与所述初级浆料混合搅拌，制备二级浆料；
    所述第四搅拌中，将溶剂与所述二级浆料混合搅拌，制备正极浆料；
    所述第二搅拌中使用的溶剂与所述第四搅拌中使用的溶剂相同，基于所述正极活性材料的质量计，所述第二搅拌中使用的溶剂的质量比为35％～40％，所述第四搅拌中使用的溶剂的质量比为5％～10％。
  2. 根据权利要求1所述的正极浆料的制备方法，其特征在于，所述粘结剂包含至少一种重均分子量为40万～180万的聚偏氟乙烯。
  3. 根据权利要求1或2所述的正极浆料的制备方法，其特征在于，所述粘结剂至少包含两种重均分子量的差值不大于180万的聚偏氟乙烯。
  4. 根据权利要求1至3中任一项所述的正极浆料的制备方法，其特征在于，所述第一搅拌的自转速度为0。
  5. 根据权利要求1至4中任一项所述的正极浆料的制备方法，其特征在于，所述第一搅拌的搅拌时间为15分钟～30分钟。
  6. 根据权利要求1至5中任一项所述的正极浆料的制备方法，其特征在于，所述第一搅拌的公转速度为10转/分钟～20转/分钟。
  7. 根据权利要求1至6中任一项所述的正极浆料的制备方法，其特征在于，所述第二搅拌的搅拌时间为50分钟～80分钟。
  8. 根据权利要求1至7中任一项所述的正极浆料的制备方法，其特征在于，所述第二搅拌的公转速度为15转/分钟～30转/分钟。
  9. 根据权利要求1至8中任一项所述的正极浆料的制备方法，其特征在于，所述第二搅拌的自转速度800转/分钟～1300转/分钟。
  10. 根据权利要求1至9中任一项所述的制备方法，其特征在于，所述第三搅拌的搅拌时间为100分钟～130分钟。
  11. 根据权利要求1至10中任一项所述的制备方法，其特征在于，所述第三搅拌的公转速度为20转/分钟～40转/分钟。
  12. 根据权利要求1至11中任一项所述的制备方法，其特征在于，所述第三搅拌的自转速度为1000转/分钟～1300转/分钟。
  13. 根据权利要求1至12中任一项所述的制备方法，其特征在于，所述第四搅拌的搅拌时间为30分钟～50分钟。
  14. 根据权利要求1至13中任一项所述的制备方法，其特征在于，所述第四搅拌的公转速度为20转/分钟～40转/分钟。
  15. 根据权利要求1至14中任一项所述的制备方法，其特征在于，所述第四搅拌的自转速度为1000转/分钟～1300转/分钟。
  16. 根据权利要求1至15中任一项所述的制备方法，其特征在于，所述正极活性材料的质量为900kg～1300kg；
  17. 根据权利要求1至16中任一项所述的制备方法，其特征在于，所述正极浆料中，正极活性材料、粘结剂、导电剂的质量比为(95～98.5)∶(1～3)∶(0.5～1)。
  18. 根据权利要求1至17中任一项所述的制备方法，所述正极活性材料为磷酸铁锂、钴酸锂、钛酸锂、镍钴锰酸锂中的一种或几种。
  19. 一种正极浆料，其特征在于，所述正极浆料的固含量为65％～70％，所述正极浆料的初始粘度为1000～35000mPa·s，且所述正极浆料在静置24小时后，所述正极浆料的粘度不超过50000mPa·s。
  20. 根据权利要求19所述的正极浆料，其特征在于，所述正极浆料是由权利要求1至18中任一项所述的正极浆料的制备方法制备的。
  21. 一种二次电池，其特征在于，包括正极极片、隔离膜、负极极片以及电解液，所述正极极片由权利要求1至18中任一项所述的正极浆料的制备方法制备的正极浆料制备而得。
  22. 根据权利要求21所述的二次电池，其特征在于，所述二次电池为锂离子电池、钠离子电池、镁离子电池、钾离子电池中的任意一种。
  23. 一种电池模块，其特征在于，包括权利要求21或22所述的二次电池。
  24. 一种电池包，其特征在于，包括权利要求21或22所述的二次电池、权利要求23所述的电池模块中的至少一种。
  25. 一种用电装置，其特征在于，包括选自权利要求21或22所述的二次电池、权利要求23所述的电池模块或权利要求24所述的电池包中的至少一种。
PCT/CN2022/131506 2022-11-11 2022-11-11 正极浆料的制备方法、二次电池、电池包和用电装置 WO2024098410A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/131506 WO2024098410A1 (zh) 2022-11-11 2022-11-11 正极浆料的制备方法、二次电池、电池包和用电装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/131506 WO2024098410A1 (zh) 2022-11-11 2022-11-11 正极浆料的制备方法、二次电池、电池包和用电装置

Publications (1)

Publication Number Publication Date
WO2024098410A1 true WO2024098410A1 (zh) 2024-05-16

Family

ID=91031773

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/131506 WO2024098410A1 (zh) 2022-11-11 2022-11-11 正极浆料的制备方法、二次电池、电池包和用电装置

Country Status (1)

Country Link
WO (1) WO2024098410A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101414694A (zh) * 2007-10-17 2009-04-22 江苏和信电气制造有限公司 锂离子动力电池电芯制造工艺
CN102024940A (zh) * 2010-10-29 2011-04-20 安徽中菱电动汽车有限公司 一种锂离子动力电池电芯正、负极浆料的生产工艺
CN106450171A (zh) * 2016-11-09 2017-02-22 深圳拓邦新能源技术有限公司 锂离子电池正极浆料及其制备方法、极片锂离子电池
CN111834619A (zh) * 2020-06-19 2020-10-27 湖北亿纬动力有限公司 一种正极浆料及其制备方法和用途
CN112635715A (zh) * 2020-12-18 2021-04-09 湖北亿纬动力有限公司 一种锂离子电池正极浆料、其匀浆方法及用途
JP2022168684A (ja) * 2021-04-26 2022-11-08 古河電池株式会社 リチウムイオン電池用正極の製造方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101414694A (zh) * 2007-10-17 2009-04-22 江苏和信电气制造有限公司 锂离子动力电池电芯制造工艺
CN102024940A (zh) * 2010-10-29 2011-04-20 安徽中菱电动汽车有限公司 一种锂离子动力电池电芯正、负极浆料的生产工艺
CN106450171A (zh) * 2016-11-09 2017-02-22 深圳拓邦新能源技术有限公司 锂离子电池正极浆料及其制备方法、极片锂离子电池
CN111834619A (zh) * 2020-06-19 2020-10-27 湖北亿纬动力有限公司 一种正极浆料及其制备方法和用途
CN112635715A (zh) * 2020-12-18 2021-04-09 湖北亿纬动力有限公司 一种锂离子电池正极浆料、其匀浆方法及用途
JP2022168684A (ja) * 2021-04-26 2022-11-08 古河電池株式会社 リチウムイオン電池用正極の製造方法

Similar Documents

Publication Publication Date Title
WO2011079735A1 (zh) 大容量动力锂离子电池及其制备方法
CN116231091B (zh) 锂二次电池用电解液、二次电池和用电装置
CN115133036B (zh) 粘结剂、制备方法、正极极片、二次电池及用电装置
CN115133033B (zh) 粘结剂、制备方法、正极极片、二次电池及用电装置
CN104134782A (zh) 一种纳米化磷酸铁锂锂离子电池正极材料及其制备方法
WO2023082918A1 (zh) 锂离子电池、电池模块、电池包及用电装置
WO2023185206A1 (zh) 一种电化学装置及包含其的电器
CN113889594A (zh) 一种硼掺杂锆酸镧锂包覆石墨复合材料的制备方法
CN117638072A (zh) 含氟聚合物、其制备方法和用途，粘结剂组合物、二次电池、电池模块、电池包及用电装置
WO2023197807A1 (zh) 正极材料及其制备方法、复合正极材料、正极极片及二次电池
WO2023124913A1 (zh) 负极活性材料、其制备方法及其相关的二次电池和装置
WO2023078047A1 (zh) 正极活性材料、其制备方法、包括其的锂离子电池、电池模块、电池包和用电装置
WO2023108352A1 (zh) 一种正极活性材料及其相关的极片、二次电池、电池模块、电池包和装置
WO2024098410A1 (zh) 正极浆料的制备方法、二次电池、电池包和用电装置
WO2022266886A1 (zh) 类sei膜组分添加剂的制备方法和电解液、锂离子电池、电池模块、电池包和用电装置
WO2024098412A1 (zh) 正极浆料的制备方法、二次电池、电池包和用电装置
WO2024098419A1 (zh) 正极浆料的制备方法、二次电池、电池包和用电装置
WO2024098411A1 (zh) 正极浆料的制备方法、正极极片、二次电池、电池模块、电池包和用电装置
WO2024020795A1 (zh) 一种复合正极材料、其制备方法、二次电池、电池模块、电池包和用电装置
WO2024031448A1 (zh) 聚合物及其制备方法、正极浆料、正极极片、二次电池、电池模块、电池包和用电装置
WO2024011511A1 (zh) 正极浆料及其制备方法、正极极片、二次电池、电池模块、电池包及用电装置
WO2023130212A1 (zh) 一种锂离子二次电池、电池模块、电池包和用电装置
CN116525766B (zh) 二次电池及用电装置
CN116914293B (zh) 一种电池
WO2023168553A1 (zh) 电池模组、电池包和用电装置

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: 22964878

Country of ref document: EP

Kind code of ref document: A1