WO2023197615A1 - 一种具有造孔功能涂层的集流体、极片以及电池 - Google Patents

一种具有造孔功能涂层的集流体、极片以及电池 Download PDF

Info

Publication number
WO2023197615A1
WO2023197615A1 PCT/CN2022/134959 CN2022134959W WO2023197615A1 WO 2023197615 A1 WO2023197615 A1 WO 2023197615A1 CN 2022134959 W CN2022134959 W CN 2022134959W WO 2023197615 A1 WO2023197615 A1 WO 2023197615A1
Authority
WO
WIPO (PCT)
Prior art keywords
functional coating
current collector
pore
coating
gas
Prior art date
Application number
PCT/CN2022/134959
Other languages
English (en)
French (fr)
Inventor
曹辉
姚毅
侯敏
刘婵
郭颖颖
杨雅晴
Original Assignee
瑞浦兰钧能源股份有限公司
上海瑞浦青创新能源有限公司
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 瑞浦兰钧能源股份有限公司, 上海瑞浦青创新能源有限公司 filed Critical 瑞浦兰钧能源股份有限公司
Publication of WO2023197615A1 publication Critical patent/WO2023197615A1/zh

Links

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
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H01M4/80—Porous plates, e.g. sintered carriers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/668—Composites of electroconductive material and synthetic resins
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to the technical field of battery manufacturing, and specifically, to a current collector, a pole piece and a battery with a pore-forming functional coating.
  • Lithium-ion batteries have become one of the most widely used choices in energy storage and power battery applications due to their high energy density and long service life.
  • lithium-ion batteries are often designed to increase the mass proportion of active materials and reduce the use of auxiliary materials.
  • the thickness of the coating will inevitably increase, resulting in a longer diffusion path of lithium ions in the battery, hindering the performance of materials close to the current collector, and ultimately affecting the dynamic performance of the battery. This goes against users' demands for fast charging and high power of batteries.
  • Patent CN110957470B adds a pore-forming agent to the battery active material slurry to prepare a lithium-ion battery pole piece with an active coating with a pore structure.
  • the content of the pore-forming agent in the slurry is 10% to 30% of the total solid content.
  • Such a high proportion of pore-forming agents will form a large number of holes in the coating. Although it may improve the kinetic performance of the battery, it may also lead to pits on the film surface and uneven distribution of active materials, which will affect the long-term battery cycle. During the process, problems such as black spots and lithium precipitation occur due to uneven lithium insertion.
  • CN102655229A proposes a method of using a pore-forming agent to dissolve and precipitate, then press into the active material coating layer, and decompose it at a later stage to produce pole pieces with through holes.
  • the depth of the pores generated by this method depends on the concentration of the precipitated pore-forming agent. The grain size and orientation are highly random and cannot ensure that the pores penetrate to the bottom of the active material coating.
  • WO2021138814A1 proposes a method of using a gravure roller to create through holes on pole pieces.
  • This method creates an uncoated area on the current collector during the coating process.
  • the uncoated area may be covered by the liquid film due to the surface tension of the slurry, forming an impenetrable hole; in addition, this method requires equipment to be inspected. Construction to use gravure rollers is more expensive.
  • the object of the present invention is to provide a current collector, a pole piece and a battery with a pore-forming functional coating.
  • a first aspect of the present invention provides a current collector with a pore-forming functional coating, including a conductive base layer and a functional coating coated on at least one surface of the base layer, wherein the functional coating contains a component with a decomposition temperature of 250°C.
  • the following gas-generating compounds are capable of producing gas. Predistributing the gas-generating compound on the current collector can reduce the usage of the gas-generating compound compared with the prior art solution of dispersing it in the active material coating slurry, ensuring that the decomposition of the gas-generating compound is eliminated. There will be no decomposition of gas-generating compounds on the surface of the coated wet film on the surface of the current collector or under the coating slurry.
  • the smaller amount of gas-generating compounds can also reduce the generation of corrosive gases such as ammonia, which will have less adverse effects on drying equipment and operators.
  • the current collector of the present invention does not contain positive electrode active material and negative electrode active material.
  • the gas-generating compound decomposes to form bubbles when the current collector with the pore-forming functional coating is coated with the positive electrode slurry or the negative electrode slurry and then dried, thereby constructing a bottom-up penetrating structure composed of the positive electrode slurry. Or the through holes of the active material coating formed by drying the negative electrode slurry.
  • the present invention pre-distributes the gas-generating compound on the current collector, and decomposes to form bubbles during the coating and drying process of the battery pole piece, thereby constructing through-holes penetrating the active material coating from bottom to top.
  • the conductive base layer includes copper foil, aluminum foil or a polymer foil with a metal plating layer attached to its surface.
  • the conductive base layer is selected from copper foil, aluminum foil, or a polymer foil with a metal plating layer attached to its surface.
  • the compounds capable of producing gas with a decomposition temperature below 250°C include one or more of ammonium bicarbonate, ammonium carbonate, ammonium oxalate, and ammonium hydrogen oxalate.
  • the gas generating compound is selected from one or more of ammonium bicarbonate, ammonium carbonate, ammonium oxalate, and ammonium bicarbonate.
  • the functional coating does not contain positive active material and negative active material.
  • the functional coating further includes one or more selected from conductive agents and binders.
  • the functional coating consists of a gas-generating compound and optionally one or more selected from the group consisting of a conductive agent and a binder.
  • the functional coating includes a gas generating compound, a conductive agent, and a binder.
  • the coating amount D (ie, surface density) of the gas-generating compound on the current collector per unit area satisfies: 0 ⁇ D ⁇ 60g/m 2 .
  • the coating amount D in the present invention is the total coating amount of the gas-generating compound in the two functional coatings on the current collector per unit area.
  • the coating amount D of the gas-generating compound on the current collector per unit area satisfies: 0 ⁇ D ⁇ 35g/m 2 .
  • the coating amount D of the gas-generating compound on the current collector per unit area satisfies: 10 ⁇ D ⁇ 35g/m 2 .
  • the coating amount D of the gas-generating compound on the current collector per unit area satisfies: 20 ⁇ D ⁇ 35g/m 2 .
  • the conductive agent includes one or more of activated carbon, carbon black, graphite, carbon nanotubes, and carbon fibers.
  • the binder is a polymer binder.
  • the polymer binder suitable for the present invention includes one or more of polyvinylidene fluoride, polymethyl acrylate, styrene-butadiene rubber, sodium carboxymethylcellulose, lithium carboxymethylcellulose, polyvinyl alcohol, and polyurethane. kind.
  • the coating amount D1 i.e. surface density of the conductive agent on the current collector per unit area satisfies: 0 ⁇ D1 ⁇ 2g/m 2 , for example, D1 can be 0.1g/m 2 , 0.2g/m 2 , 0.5g/m 2 , 1g/m 2 .
  • the coating amount D i.e. surface density of the binder on the current collector per unit area satisfies: 0 ⁇ D2 ⁇ 2g/m 2 , for example, D2 can be 0.1g/m 2 , 0.2g/m 2 , 0.5g/m 2 , 1g/m 2 .
  • a second aspect of the present invention provides a method for preparing a current collector with a pore-forming functional coating, which includes the following steps: dissolving and dispersing a gas-generating compound, a binder (optional) and a conductive agent (optional) in a solvent Form a functional coating slurry, use a coater to transfer the slurry to at least one surface of the conductive base layer, and then dry the coating to form a current collector with a functional coating. After drying, the surface density of the gas-generating compound is 0 ⁇ D ⁇ 60g/m 2 .
  • a third aspect of the present invention provides a battery electrode sheet, which is prepared by using the current collector with a pore-forming functional coating according to any embodiment of the present invention.
  • a fourth aspect of the present invention provides a method for preparing battery electrode sheets, the method comprising the following steps:
  • step (2) the gas-generating compound in the functional coating is decomposed to form bubbles during the drying process by controlling the drying temperature.
  • a fifth aspect of the present invention provides a battery, including the battery electrode sheet according to any embodiment of the present invention.
  • the battery may be a lithium ion battery.
  • the present invention has the following beneficial effects:
  • the functional layer of the current collector of the present invention is coated with a compound with gas-generating decomposition properties, which can produce through-flow active materials by decomposing the gas-generating compound at the bottom of the active material coating to produce gas without affecting the existing coating process. Coated through holes, thereby improving the dynamic performance of battery products.
  • the existence of through-holes can optimize the pore structure in the battery pole piece, allowing it to have better capacity and rate performance under the same compaction density. This method is simple, easy to implement, low in cost, suitable for promotion, and has high application value.
  • the gas-generating compound is pre-distributed on the current collector.
  • the usage of the gas-generating compound can be reduced, ensuring the production of gas-generating compounds.
  • the decomposition of gas-generating compounds occurs on the surface of the current collector or the lower part of the active material coating, and the decomposition of gas-generating compounds on the surface of the coated wet film does not occur.
  • the smaller amount of gas-generating compounds can also reduce the generation of corrosive gases such as ammonia, which will have less adverse effects on drying equipment and operators.
  • Binders and conductive agents can also be added to the functional coating of the current collector of the present invention to further enhance the bonding force and electronic conductivity between the current collector and the active material coating, and cooperate with the through holes generated by the gas-generating compound. Further improve the cycle stability and power performance of the battery during use.
  • the surface of the current collector for the lithium-ion battery of the present invention contains compounds that can decompose to produce gas at low temperatures (less than 250°C), and can decompose to form bubbles during the coating and drying process of the battery pole pieces, thereby constructing a bottom-up penetrating active material. Coated through holes. These through holes can serve as diffusion channels for lithium ions in the electrolyte, reducing the diffusion resistance of lithium ions on the surface of the active material near the current collector surface in the active coating, thereby improving the overall dynamic performance of the battery. The existence of through-holes can optimize the pore structure in the lithium-ion battery pole piece, allowing it to have better capacity and rate performance under the same compaction density.
  • the conductive substrate in the current collector can use common choices in the art.
  • Useful conductive substrates include one or more selected from metal foils (eg, copper foil, aluminum foil) and composite foils (eg, polymer foils with metal plating attached to the surface).
  • the conductive substrate includes aluminum foil for the positive electrode and copper foil for the negative electrode.
  • a metal-coated composite current collector with a polymer substrate may also be used.
  • the gas-generating compound may be selected from one or more of ammonium bicarbonate, ammonium carbonate, ammonium oxalate, and ammonium hydrogen oxalate.
  • the decomposition temperatures of these compounds are above room temperature and below 250°C to ensure that they will not decompose during the current collector preparation process, nor will they be higher than the oxidation temperature of the conductive substrate (such as metal or composite foil) in the air.
  • the pore-forming agent is an ammonium ion-containing compound
  • ammonia gas is generated during the high-temperature drying process.
  • ammonia can cause damage to lithium battery production equipment during use.
  • Coating a relatively small amount of pore-forming agent on the current collector can, on the one hand, help build through-type pore channels and improve the battery kinetic performance at a lower pore-forming agent addition amount.
  • it can reduce the generation of Ammonia gas can reduce corrosion of equipment and extend the service life of equipment, thereby reducing additional costs caused by equipment loss during the production process.
  • Binders and conductive agents can also be added to the functional coating of the current collector of the present invention to further enhance the bonding force and electronic conductivity between the current collector and the active material coating, and cooperate with the through holes generated by the gas-generating compound to further Improve the cycle stability and power performance of the battery during use.
  • the positive electrode slurry and the negative electrode slurry refer to the active material coating slurry containing the positive electrode active material or the negative electrode active material used to form the positive electrode active material coating and the negative electrode active material coating, respectively.
  • the functional coating of the current collector of the present invention and the functional coating slurry used to form the functional coating do not contain positive active materials and negative electrodes. active materials.
  • the meanings of positive active material and negative active material are well known to those skilled in the art.
  • NMP N-methylpyrrolidone
  • a functional coating slurry with a solid content (i.e. mass concentration) of 10%.
  • NMP N-methylpyrrolidone
  • a coater to transfer the slurry to the surface of the aluminum foil, and then heat it at 30°C.
  • the coating is dried to form a current collector with a functional coating.
  • the functional coating slurry is coated on both sides, and the ammonium bicarbonate surface density after drying is 35g/m 2 .
  • the functional coating slurry is coated on both sides, and the surface density of ammonium bicarbonate after drying is 20g/m 2 .
  • VDF polyvinylidene fluoride
  • Use a coater to transfer the slurry to The surface of the copper foil is then dried at 30°C to form a current collector with a functional coating.
  • the functional coating slurry is coated on both sides. After drying, the ammonium bicarbonate surface density is 20g/m 2 and the CMC surface density is 0.2g/m 2 .
  • the functional coating slurry is coated on both sides. After drying, the ammonium bicarbonate surface density is 10g/m 2 and the CMC surface density is 0.5g/m 2 .
  • the functional coating slurry is double-sided coating. After drying, the surface density of ammonium bicarbonate is 50g/m 2 , the surface density of PVDF is 0.5g/m 2 , and the surface density of carbon black is 0.5g/m 2 .
  • the functional coating slurry is double-sided coating. After drying, the areal density of ammonium carbonate is 35g/m 2 , the areal density of PVDF is 0.35g/m 2 , and the areal density of carbon black is 0.35g/m 2 .
  • the functional coating slurry is double-sided coating. After drying, the surface density of ammonium hydrogen oxalate is 35g/m 2 , the surface density of PVDF is 0.35g/m 2 , and the surface density of carbon black is 0.35g/m 2 .
  • Ammonium oxalate and PVDF are dissolved and dispersed in NMP at a mass ratio of 100:1 to form a functional coating slurry with a solid content of 10.1%.
  • the functional coating slurry is coated on both sides. After drying, the ammonium oxalate area density is 35g/m 2 and the PVDF area density is 0.35g/m 2 .
  • the preparation method is the same as Example 3, except that ammonium bicarbonate is not added to the functional coating slurry.
  • the preparation method is the same as in Example 4, except that ammonium bicarbonate is not added to the functional coating slurry.
  • Ammonium bicarbonate and PVDF are dissolved and dispersed in NMP at a mass ratio of 200:1 to form a functional coating slurry with a solid content of 20.1%.
  • the layers form a current collector with a functional coating.
  • the functional coating slurry is coated on both sides. After drying, the ammonium bicarbonate surface density is 100g/m 2 and the PVDF surface density is 0.5g/m 2 .
  • the preparation method is the same as Example 7, except that no ammonium carbonate is added to the functional coating slurry.
  • the current collectors prepared in the above examples and Comparative Examples 1-4 are used to prepare lithium-ion batteries.
  • the battery preparation method is as follows:
  • Preparation of the positive electrode sheet Mix the NCM523 positive active material, the conductive agent carbon black, and the binder polyvinylidene fluoride (PVDF) at a mass ratio of 97.2:1.5:1.3 and add the organic solvent NMP and stir at high speed to form a solid A homogeneous dispersion containing 70%; after high-speed stirring, negative pressure defoaming is performed in the stirring tank to obtain a positive electrode slurry suitable for coating. The obtained positive electrode slurry is coated on the current collector through a transfer coater, and then dried, cold pressed, and slit into positive electrode pieces of the desired shape.
  • PVDF polyvinylidene fluoride
  • the drying temperatures selected are: ammonium bicarbonate 120°C, ammonium carbonate 170°C, ammonium hydrogen oxalate 210°C, and ammonium oxalate 210°C.
  • the total surface density of the coating remaining on the pole piece after drying is 400g/m 2 .
  • the compaction density of the positive active material coating area was controlled at 3.45g/cm 3 .
  • the drying temperatures selected are: ammonium bicarbonate 120°C, ammonium carbonate 170°C, ammonium hydrogen oxalate 210°C, and ammonium oxalate 210°C.
  • the total surface density of the coating remaining on the pole piece after drying is 245g/m 2 .
  • the compaction density of the negative active material coating area was controlled to be 1.65g/cm 3 .
  • Comparative Example 5 uses aluminum foil as the positive electrode current collector and copper foil as the negative electrode current collector, and prepares a lithium-ion battery according to the following method:
  • Preparation of the positive electrode sheet Mix the NCM523 positive active material, the conductive agent carbon black, and the binder polyvinylidene fluoride (PVDF) at a mass ratio of 97.2:1.5:1.3 and add the organic solvent NMP and stir at high speed to form a solid A uniform dispersion containing 70%; add ammonium bicarbonate powder to this dispersion, with a mass ratio of 5 (ammonium bicarbonate): 100 (NCM523 positive active material + conductive agent carbon black + polyvinylidene fluoride); stir at high speed After completion, negative pressure defoaming is performed in the stirring tank to obtain a positive electrode slurry suitable for coating.
  • PVDF binder polyvinylidene fluoride
  • the obtained positive electrode slurry is coated on the aluminum foil through a transfer coater, dried, cold pressed, and slit into positive electrode sheets of the desired shape.
  • the temperature selected for the drying process is 120°C.
  • the total surface density of the coating remaining on the pole piece after drying is 400g/m 2 .
  • the compaction density of the positive active material coating area was controlled at 3.45g/cm 3 .
  • Rate test Use charging and discharging equipment to charge and discharge the battery at a rate of 1C (that is, the battery's rated capacity ampere-hours is set to the current size) and 3C, and record the battery capacity Cap 1C and Cap 3C during the discharge process.
  • Lithium precipitation test Use charging and discharging equipment to charge and discharge the battery 10 times at 3C. After completion, disassemble the battery and observe the surface of the negative electrode piece. If there is no obvious gray-white color, it is considered as no lithium precipitation. If there is no gray-white color in flakes, it is considered as slight lithium precipitation. If there is gray-white color in flakes, it is considered as lithium precipitation.
  • Table 1 Performance test data of lithium-ion batteries prepared by current collectors of various examples and comparative examples
  • Example 1 copper foil 86.1% Slight lithium precipitation 2 aluminum foil
  • Example 2 91.5% Does not analyze lithium 3
  • Example 3 copper foil 88.4% Does not analyze lithium 4
  • Example 3 Example 4 92.4% Does not analyze lithium 5
  • Example 3 Example 5
  • Example 4 92.7% Does not analyze lithium 7
  • Example 7 Example 4 91.6% Does not analyze lithium 8
  • Example 4 92.2% Does not analyze lithium 9
  • Example 4 92.1% Does not analyze lithium 10 aluminum foil copper foil 81.1% Lithium precipitation 11 Comparative example 1 copper foil 80.4% Lithium precipitation 12 aluminum foil Comparative example 2 80.2% Lithium precipitation 13 Comparative example 3 copper foil 77.4% Lithium precipitation 14 Comparative example 4 copper foil 81.8% Lithium precipitation Comparative example 5 aluminum foil copper foil 84.7% Slight lithium precipitation
  • Groups 1-9 used the current collector described in the present invention, and it was found that the battery produced had a higher 3C capacity retention rate and better lithium evolution performance.
  • both the positive and negative electrodes use current collectors with pore-forming functional coatings.
  • the dynamic properties of the positive and negative electrodes are simultaneously improved and can match each other, thus achieving better dynamic performance.
  • the preferred pore-forming agent addition amount in the present invention is in a lower range.

Landscapes

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

Abstract

本发明提供了一种具有造孔功能涂层的集流体、极片以及电池。本发明的具有造孔功能涂层的集流体包括导电基底层以及涂布在基底层至少一个表面上的功能涂层，所述功能涂层中包含分解温度在250℃以下能够产生气体的产气化合物。本发明集流体的功能层中涂布有产气分解特性的化合物，能够在不对现有涂布工艺造成影响的前提下通过造孔化合物在活性涂层底部分解产气制造贯通涂层的通孔，从而提高电池产品的动力学性能。该方法简单易行，成本低廉，适合推广，具有较高的应用价值。

Description

一种具有造孔功能涂层的集流体、极片以及电池 技术领域
本发明涉及电池制造技术领域，具体地，涉及一种具有造孔功能涂层的集流体、极片以及电池。
背景技术
锂离子电池由于其能量密度高、使用寿命长等优点已经成为储能以及动力电池应用中应用最为广泛的选择之一。为获得更高的能量效率并且降低电池的制造成本，锂离子电池在设计时往往希望能够提高活性物质的质量占比，降低辅助材料的使用量。但是在提高活性物质涂布量的同时涂层的厚度会不可避免的增加，导致电池中锂离子的扩散路径变长，靠近集流体的材料性能发挥受阻，最终影响电池的动力学性能。这与使用者对电池快充、高功率的需求背道而驰。
为解决这一问题，可以考虑优化电池中极片的孔道结构。构筑贯穿活性材料涂层的通孔能够构造出电解液和锂离子的扩散通路，有助于提升厚涂层电芯的动力学性能。
专利CN110957470B在电池活性物质浆料中加入造孔剂制备出具有孔道结构活性涂层的锂离子电池极片，浆料中造孔剂的含量为总固含的10％～30％。如此高比例的造孔剂会在涂层中形成大量的孔洞，尽管可能带来电池动力学性能上的提升，却也可能导致膜面凹坑以及活性物质分布不均，进而在电池的长期循环过程中产生因为嵌锂不均匀而出现的黑斑、析锂等问题。而且由于造孔剂的分解在浆料形成的湿膜中随机发生，可能存在部分造孔剂直接在浆料表面分解，从而产生浪费的现象。CN102655229A提出了一种使用造孔剂溶解析出后压入活性材料涂布层，并在后期升温分解的方法来制造具有通孔的极片，但是该方法生成的孔道深度取决于析出造孔剂的晶粒尺寸和导向，具有较强的随机性，不能保证孔道贯穿至活性材料涂层底部。WO2021138814A1提出了一种使用凹版辊在极片上制造通孔的方法。该方法在涂布过程中在集流体上制造未涂布区域，但是实际使用过程中未涂布区可能因为浆料的表面张力被液膜覆盖，形成不通孔；另外，该方法需要对设备进行改造，使用 凹版辊，成本较高。
发明内容
针对现有技术中的缺陷，本发明的目的是提供一种具有造孔功能涂层的集流体、极片以及电池。
本发明的目的是通过以下方案实现的：
本发明的第一方面提供一种具有造孔功能涂层的集流体，包括导电基底层以及涂布在基底层至少一个表面上的功能涂层，所述功能涂层中包含分解温度在250℃以下能够产生气体的产气化合物。将产气化合物预先分布在集流体上，与现有技术中将其分散在活性材料涂层浆料中的技术方案相比，可以减少产气化合物的使用量，确保了产气化合物的分解都在集流体表面或者涂层浆料下部，不会发生产气化合物在涂布湿膜表面分解的情况。此外，较少的产气化合物用量还能够减少氨气等腐蚀性气体的产生，对于干燥设备以及操作人员的不利影响都更小。不同于含正极活性材料或负极活性材料的极片，本发明的集流体不含正极活性材料和负极活性材料。
本发明中，所述产气化合物在所述具有造孔功能涂层的集流体涂布正极浆料或负极浆料后干燥的过程中分解形成气泡，从而构筑自下而上贯通由正极浆料或负极浆料干燥而成的活性材料涂层的通孔。
在一些实施方案中，本发明将产气化合物预先分布在集流体上，在电池极片涂布干燥的过程中分解形成气泡，从而构筑自下而上贯通活性材料涂层的通孔。
优选的，所述导电基底层包括铜箔、铝箔或表面附着有金属镀层的聚合物箔材。在一些实施方案中，所述导电基底层选自铜箔、铝箔或表面附着有金属镀层的聚合物箔材。
优选的，所述分解温度在250℃以下能够产生气体的化合物(即产气化合物)包括碳酸氢铵、碳酸铵、草酸铵、草酸氢铵中的一种或多种。在一些实施方案中，产气化合物选自碳酸氢铵、碳酸铵、草酸铵、草酸氢铵中的一种或多种。
优选的，所述功能涂层不包含正极活性材料和负极活性材料。
在一些实施方案中，所述功能涂层还包含选自导电剂和粘结剂中的一种或多种。
在一些实施方案中，所述功能涂层由产气化合物和任选的选自导电剂和粘结剂中的一种或多种组成。
在一些实施方案中，所述功能涂层中包含产气化合物、导电剂和粘结剂。
优选的，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D(即面密度)满足：0＜D≤60g/m 2。本文中，当功能涂层涂布在导电基底的两个表面上时，本发明中的涂布量D为两个功能涂层中产气化合物在单位面积集流体上的总的涂布量。
优选的，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：0＜D≤35g/m 2。
优选的，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：10≤D≤35g/m 2。
优选的，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：20≤D≤35g/m 2。
在一些实施方案中，所述导电剂包括活性炭、炭黑、石墨、碳纳米管、碳纤维中的一种或多种。
在一些实施方案中，所述粘结剂为高分子粘结剂。适用于本发明的高分子粘结剂包括聚偏氟乙烯、聚丙烯酸甲酯、丁苯橡胶、羧甲基纤维素钠、羧甲基纤维素锂、聚乙烯醇、聚氨酯中的一种或多种。
优选的，在功能涂层中，所述导电剂在单位面积集流体上的涂布量D1(即面密度)满足：0＜D1≤2g/m 2，例如D1可以是0.1g/m 2、0.2g/m 2、0.5g/m 2、1g/m 2。
优选的，在功能涂层中，所述粘结剂在单位面积集流体上的涂布量D(即面密度)满足：0＜D2≤2g/m 2，例如D2可以是0.1g/m 2、0.2g/m 2、0.5g/m 2、1g/m 2。
本发明的第二方面提供一种具有造孔功能涂层的集流体的制备方法，包括如下步骤：将产气化合物、粘结剂(可选)和导电剂(可选)溶解分散在溶剂中形成功能涂层浆料，使用涂布机把浆料转移到导电基底层的至少一个表面上，然后烘干涂层形成带有功能涂层的集流体，干燥后产气化合物面密度为0＜D≤60g/m 2。
本发明的第三方面提供一种电池用电极片，其使用本发明任一实施方案所述的具有造孔功能涂层的集流体制备而成。
本发明的第四方面提供一种制备电池用电极片的方法，所述方法包括以下步骤：
(1)将正极浆料或负极浆料涂布在本发明任一实施方案所述的具有造孔功能涂层的集流体的功能涂层表面；
(2)对涂布了正极浆料或负极浆料的集流体进行干燥，使得干燥过程中所述功能涂层中的产气化合物分解形成气泡，从而构筑自下而上贯通由正极浆料或负极浆料干燥而 成的活性材料涂层的通孔。
在一些实施方案中，步骤(2)中，通过控制干燥温度使得干燥过程中所述功能涂层中的产气化合物分解形成气泡。
本发明的第五方面提供一种电池，包括本发明任一实施方案所述的电池用电极片。所述电池可以是锂离子电池。
与现有技术相比，本发明具有如下的有益效果：
1、本发明集流体的功能层中涂布有产气分解特性的化合物，能够在不对现有涂布工艺造成影响的前提下通过产气化合物在活性材料涂层底部分解产气制造贯通活性材料涂层的通孔，从而提高电池产品的动力学性能。贯通孔道的存在可以实现电池极片中孔隙结构的优化，使其在相同压实密度下具有更好容量发挥以及倍率性能。该方法简单易行，成本低廉，适合推广，具有较高的应用价值。
2、本发明中将产气化合物预先分布在集流体上，与现有技术中将其分散在活性材料涂层浆料中的技术方案相比，可以减少产气化合物的使用量，确保了产气化合物的分解都在集流体表面或者活性材料涂层的下部，不会发生产气化合物在涂布湿膜表面分解的情况。此外，较少的产气化合物用量还能够减少氨气等腐蚀性气体的产生，对于干燥设备以及操作人员的不利影响都更小。
3、本发明集流体的功能涂层中还可加入粘结剂以及导电剂，进一步增强集流体与活性材料涂层之间的粘结力以及电子电导，与产气化合物生成的通孔配合，进一步提高电池在使用过程中的循环稳定性以及功率性能。
具体实施方式
下面结合具体实施例对本发明进行详细说明。以下实施例将有助于本领域的技术人员进一步理解本发明，但不以任何形式限制本发明。应当指出的是，对本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变化和改进。这些都属于本发明的保护范围。
本发明锂离子电池用集流体的表面含有低温(低于250℃)下可分解产气的化合物，能够在电池极片涂布干燥的过程中分解形成气泡，从而构筑自下而上贯通活性材料涂层的通孔。这些通孔可作为电解液中锂离子的扩散通道，降低活性涂层中靠近集流体表面处活性材料表面锂离子的扩散阻力，从而达到提高电池整体动力学性能的效果。贯通孔道的存在可以实现锂离子电池极片中孔隙结构的优化，使其在相同压实密度下具有更好 容量发挥以及倍率性能。
集流体中的导电基底可使用现有技术中的常用选择。可用的导电基底包括选自金属箔材(例如铜箔、铝箔)和复合箔材(例如表面附着有金属镀层的聚合物箔材)中的一种或多种。在一些实施方案中，导电基底包括正极使用的铝箔以及负极使用的铜箔，还可以使用具有聚合物基底的金属镀层复合集流体。
优选地，产气化合物可以选自碳酸氢铵、碳酸铵、草酸铵、草酸氢铵中的一种或多种。这些化合物的分解温度都在室温以上以及250℃以下，以保证其不会在集流体制备过程中分解，也不会高于导电基底(例如金属或者复合箔材)在空气中的氧化温度。
在造孔剂(产气化合物)为含铵离子化合物的实施方案中，在高温干燥过程中会产生氨气。作为一种腐蚀性气体，氨气在使用过程中会对锂电池生产设备造成损害。将相对较少的造孔剂涂布在集流体上，一方面有利于构筑贯通型孔道，在较低的造孔剂添加量下实现对电池动力学性能的提升，另一方面可以减少生成的氨气，降低对设备的腐蚀，延长设备的使用寿命，从而降低生产过程中因为设备损耗造成的额外成本。
在本发明集流体的功能涂层中还可加入粘结剂以及导电剂，进一步增强集流体与活性材料涂层之间的粘结力以及电子电导，与产气化合物生成的通孔配合，进一步提高电池在使用过程中的循环稳定性以及功率性能。
本发明中，正极浆料和负极浆料分别是指用于形成正极活性材料涂层和负极活性材料涂层的包含正极活性材料或负极活性材料的活性材料涂层浆料。与现有技术中将产气化合物分散在活性材料涂层浆料中不同的是，本发明集流体的功能涂层以及用于形成功能涂层的功能涂层浆料不含正极活性材料和负极活性材料。正极活性材料和负极活性材料的含义为本领域技术人员所熟知。
接下来结合具体实施例对本发明技术方案做进一步详细说明。
实施例1
将碳酸氢铵溶解分散在N-甲基吡咯烷酮(NMP)中形成固含(即质量浓度)为10％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，且涂布干燥后碳酸氢铵面密度为35g/m 2。
实施例2
将碳酸氢铵溶解分散在去离子水中形成固含为10％的功能涂层浆料，使用涂布机把浆料转移到铜箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为20g/m 2。
实施例3
将碳酸氢铵和聚偏氟乙烯(PVDF)按质量比100∶1溶解分散在NMP中形成固含为10.1％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为35g/m 2，PVDF面密度为0.35g/m 2。
实施例4
将碳酸氢铵和羧甲基纤维素钠(CMC-Na)按质量比100∶1溶解分散在去离子水中形成固含为10.1％的功能涂层浆料，使用涂布机把浆料转移到铜箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为20g/m 2，CMC面密度为0.2g/m 2。
实施例5
将碳酸氢铵和CMC-Na按质量比20∶1溶解分散在去离子水中形成固含为2.1％的功能涂层浆料，使用涂布机把浆料转移到铜箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为10g/m 2，CMC面密度为0.5g/m 2。
实施例6
将碳酸氢铵、PVDF和炭黑按质量比100∶1∶1溶解分散在NMP中形成固含为10.2％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为50g/m 2，PVDF面密度为0.5g/m 2，炭黑面密度为0.5g/m 2。
实施例7
将碳酸铵、PVDF和炭黑按质量比100∶1∶1溶解分散在NMP中形成固含为10.2％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸铵面密度为35g/m 2，PVDF面密度为0.35g/m 2，炭黑面密度为0.35g/m 2。
实施例8
将草酸氢铵、PVDF和炭黑按质量比100∶1∶1溶解分散在NMP中形成固含为10.2％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后草酸氢铵面密度为35g/m 2，PVDF面密度为0.35g/m 2，炭黑面密度为0.35g/m 2。
实施例9
将草酸铵和PVDF按质量比100∶1溶解分散在NMP中形成固含为10.1％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后草酸铵面密度为35g/m 2，PVDF面密度为0.35g/m 2。
对比例1
制备方法同实施例3，区别在于功能涂层浆料中未加入碳酸氢铵。
对比例2
制备方法同实施例4，区别在于功能涂层浆料中未加入碳酸氢铵。
对比例3
将碳酸氢铵和PVDF按质量比200∶1溶解分散在NMP中形成固含为20.1％的功能涂层浆料，使用涂布机把浆料转移到铝箔表面，然后在30℃下烘干涂层形成带有功能涂层的集流体。功能涂层浆料为双面涂布，干燥后碳酸氢铵面密度为100g/m 2，PVDF面密度为0.5g/m 2。
对比例4
制备方法同实施例7，区别在于功能涂层浆料中未加入碳酸铵。
根据表1将以上实施例和对比例1-4制得的集流体用于制备锂离子电池，电池制备方法如下：
(一)正极极片的制备：将NCM523正极活性材料与导电剂炭黑、粘结剂聚偏氟乙烯(PVDF)按照质量比为97.2∶1.5∶1.3混合并加入有机溶剂NMP中高速搅拌形成固含为70％的均匀分散液；高速搅拌结束后在搅拌罐中进行负压消泡，得到适于涂布的正极浆料。将得到的正极浆料通过转移式涂布机涂布于集流体上，经烘干、冷压、分条后制成所需形状的正极极片。当使用具有产气化合物功能涂层时选用的干燥温度分别为：碳酸氢铵120℃，碳酸铵170℃，草酸氢铵210℃，草酸铵210℃。干燥后留存在极片上的涂层面密度总计为400g/m 2。冷压过程中控制正极活性物质涂布区的压实密度在3.45g/cm 3。
(二)负极极片的制备：将人造石墨与导电剂炭黑、丁苯橡胶(SBR)、CMC-Na按照质量比为96.5∶1.2∶1.4∶0.9比例混合并加入去离子水中高速搅拌形成固含为50％的均匀分散液；高速搅拌结束后在搅拌罐中进行负压消泡，得到适于涂布的负极浆料。将得到的负极浆料通过转移式涂布机涂布于集流体上，经烘干、冷压、分条后制成所需形状的 负极极片。当使用具有产气化合物功能涂层时选用的干燥温度分别为：碳酸氢铵120℃，碳酸铵170℃，草酸氢铵210℃，草酸铵210℃。干燥后留存在极片上的涂层面密度总计为245g/m 2。冷压过程中控制负极活性物质涂布区的压实密度在1.65g/cm 3。
(三)锂离子电池的制备：将正负极片置于厚度为9μm的PE隔离膜两侧并卷绕形成卷芯，未涂布区与极耳通过超声焊连接，用铝塑膜包裹卷芯并封边，保留空隙用于电解液注液。在EC∶EMC∶DEC＝3∶5∶2(质量比)的混合溶剂中加入按电解液总质量计的11wt％的LiPF 6、1wt％(电解液总质量计)的碳酸亚乙烯酯以及2wt％(电解液总质量计)的硫酸乙烯酯(DTD)作为锂盐以及添加剂制成电解液，从保留的空隙注入前述装有卷芯的铝塑膜软包中，再经过真空封装、静置以及化成工序获得锂离子电池。
对比例5
对比例5采用铝箔作为正极集流体、铜箔作为负极集流体，按照如下方法制备锂离子电池：
(一)正极极片的制备：将NCM523正极活性材料与导电剂炭黑、粘结剂聚偏氟乙烯(PVDF)按照质量比为97.2∶1.5∶1.3混合并加入有机溶剂NMP中高速搅拌形成固含为70％的均匀分散液；向此分散液中加入碳酸氢铵粉末，质量比为5(碳酸氢铵)∶100(NCM523正极活性材料+导电剂炭黑+聚偏氟乙烯)；高速搅拌结束后在搅拌罐中进行负压消泡，得到适于涂布的正极浆料。将得到的正极浆料通过转移式涂布机涂布于铝箔上，经烘干、冷压、分条后制成所需形状的正极极片。干燥过程选择的温度为120℃。干燥后留存在极片上的涂层面密度总计为400g/m 2。冷压过程中控制正极活性物质涂布区的压实密度在3.45g/cm 3。
(二)负极极片的制备：将人造石墨与导电剂炭黑、丁苯橡胶(SBR)、CMC-Na按照质量比为96.5∶1.2∶1.4∶0.9比例混合并加入去离子水中高速搅拌形成固含为50％的均匀分散液；高速搅拌结束后在搅拌罐中进行负压消泡，得到适于涂布的负极浆料。将得到的负极浆料通过转移式涂布机涂布于铜箔上，经烘干、冷压、分条后制成所需形状的负极极片。干燥后留存在极片上的涂层面密度总计为245g/m 2。冷压过程中控制负极活性物质涂布区的压实密度在1.65g/cm 3。
(三)锂离子电池的制备：将正负极片置于厚度为9μm的PE隔离膜两侧并卷绕形成卷芯，未涂布区与极耳通过超声焊连接，用铝塑膜包裹卷芯并封边，保留空隙用于电解液注液。在EC∶EMC∶DEC＝3∶5∶2(质量比)的混合溶剂中加入按电解液总质量计的11wt％的LiPF 6、1wt％(电解液总质量计)的碳酸亚乙烯酯以及2wt％(电解液总质量计)的 DTD作为锂盐以及添加剂制成电解液，从保留的空隙注入前述装有卷芯的铝塑膜软包中，再经过真空封装、静置以及化成工序获得对比例5的锂离子电池。
将用各实施例和对比例的集流体制备的锂离子电池进行相关性能测试，结果如表1所示。电池测试方法：
(1)倍率测试：使用充放电设备以1C(即电池额定容量安时数设为电流大小)和3C的倍率对电池进行充放电操作，记录放电过程中的电池容量Cap 1C以及Cap 3C。3C容量保持率为R 3C＝Cap 3C/Cap 1C。
(2)析锂测试：使用充放电设备以3C对电池进行10次充放电操作，结束后拆解电池观察负极极片表面的情况。未见明显灰白色视为不析锂，有未成片灰白色视为轻微析锂，有成片灰白色视为析锂。
表1：各实施例和对比例的集流体制备的锂离子电池的性能测试数据
组别 正极集流体 负极集流体 R 3c 析锂测试
1 实施例1 铜箔 86.1％ 轻微析锂
2 铝箔 实施例2 91.5％ 不析锂
3 实施例3 铜箔 88.4％ 不析锂
4 实施例3 实施例4 92.4％ 不析锂
5 实施例3 实施例5 90.3％ 不析锂
6 实施例6 实施例4 92.7％ 不析锂
7 实施例7 实施例4 91.6％ 不析锂
8 实施例8 实施例4 92.2％ 不析锂
9 实施例9 实施例4 92.1％ 不析锂
10 铝箔 铜箔 81.1％ 析锂
11 对比例1 铜箔 80.4％ 析锂
12 铝箔 对比例2 80.2％ 析锂
13 对比例3 铜箔 77.4％ 析锂
14 对比例4 铜箔 81.8％ 析锂
对比例5 铝箔 铜箔 84.7％ 轻微析锂
组别1-9使用了本发明所描述集流体，可发现制得的电池具有更高的3C容量保持率 以及更优的析锂表现。
组1、2与组10对比可知，使用造孔集流体无论在正极还是负极都能够为电池提供更优的动力学性能。
组1和组3对比可知在功能涂层中加入粘结剂具有更优的效果。这是因为粘结剂的加入能够提高功能涂层浆料的工艺性能，有助于产气化合物在极片干燥过程中均匀地产生孔道。
组别4中正负极都使用了具有造孔功能涂层的集流体，正负极的动力学性能同时得到提升并且能够相互匹配，因此获得了更优的动力学性能。
组4、5相对比可知，造孔的效果随产气化合物的加入量增加有变好的趋势，但是对比组13和组3对比可知，当造孔剂(产气化合物)添加量超过本发明优选范围时，过多的气泡会导致极片活性物质涂层的不均匀，反而显著降低电池的性能表现。
组10、11、12对比可知，单纯的粘结剂在正负极集流体上都不会带来动力学性能的显著提升。
组10和组14对比可知功能涂层中如果没有产气化合物，则粘结剂+导电剂的组合亦对电池动力学性能没有帮助。
组1和组10、对比例5对比可知，将产气化合物直接放在正极浆料当中对于电池的动力学性能有帮助，但是效果不如将产气化合物放在集流体表面功能涂层当中优异。
另外，在测试中还发现组别4和6相比较，正极集流体上的较多的产气化合物虽然对于电池性能有些微的提升，但是幅度不大，同时因为造孔剂分解产生的氨气更多，会对干燥设备的内壁以及操作人员造成更为严重的威胁，故本发明优选的造孔剂添加量在一个较低的范围内。
以上对本发明的具体实施例进行了描述。需要理解的是，本发明并不局限于上述特定实施方式，本领域技术人员可以在权利要求的范围内做出各种变化或修改，这并不影响本发明的实质内容。在不冲突的情况下，本发明的实施例和实施例中的特征可以任意相互组合。

Claims (15)

  1. 一种具有造孔功能涂层的集流体，其特征在于，包括导电基底层以及涂布在基底层至少一个表面上的功能涂层，所述功能涂层包含分解温度在250℃以下能够产生气体的产气化合物。
  2. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述产气化合物在所述具有造孔功能涂层的集流体涂布正极浆料或负极浆料后干燥的过程中分解形成气泡，从而构筑自下而上贯通由正极浆料或负极浆料干燥而成的活性材料涂层的通孔。
  3. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述分解温度在250℃以下能够产生气体的产气化合物包括碳酸氢铵、碳酸铵、草酸铵、草酸氢铵中的一种或多种。
  4. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述功能涂层不包含正极活性材料和负极活性材料。
  5. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：0＜D≤60g/m 2，优选满足：0＜D≤35g/m 2。
  6. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：10≤D≤35g/m 2。
  7. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，在功能涂层中，所述产气化合物在单位面积集流体上的涂布量D满足：20≤D≤35g/m 2。
  8. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述导电基底层包括铜箔、铝箔或表面附着有金属镀层的聚合物箔材。
  9. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述功能涂层还包含选自导电剂和粘结剂中的一种或多种。
  10. 根据权利要求1所述的具有造孔功能涂层的集流体，其特征在于，所述功能涂层由产气化合物和任选的选自导电剂和粘结剂中的一种或多种组成。
  11. 根据权利要求9或10所述的具有造孔功能涂层的集流体，其特征在于，所述导电剂包括活性炭、炭黑、石墨、碳纳米管、碳纤维中的一种或多种；所述粘结剂包括聚偏氟乙烯、聚丙烯酸甲酯、丁苯橡胶、羧甲基纤维素钠、羧甲基纤维素锂、聚乙烯醇、聚氨酯中的一种或多种。
  12. 根据权利要求9或10所述的具有造孔功能涂层的集流体，其特征在于，在功能涂层中，所述导电剂在单位面积集流体上的涂布量D1满足：0＜D1≤2g/m 2，所述粘结剂在单位面积集流体上的涂布量D2满足：0＜D2≤2g/m 2。
  13. 一种电池用电极片，其特征在于，使用权利要求1至12中任一项所述的具有造孔功能涂层的集流体制备而成。
  14. 制备权利要求13所述的电池用电极片的方法，其特征在于，所述方法包括以下步骤：
    (1)将正极浆料或负极浆料涂布在所述具有造孔功能涂层的集流体的功能涂层表面；
    (2)对涂布了正极浆料或负极浆料的集流体进行干燥，使得干燥过程中所述功能涂层中的产气化合物分解形成气泡。
  15. 一种电池，其特征在于，包括权利要求13所述的电池用电极片。
PCT/CN2022/134959 2022-04-12 2022-11-29 一种具有造孔功能涂层的集流体、极片以及电池 WO2023197615A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210377143.9A CN114464816B (zh) 2022-04-12 2022-04-12 一种具有造孔功能涂层的集流体、极片以及锂离子电池
CN202210377143.9 2022-04-12

Publications (1)

Publication Number Publication Date
WO2023197615A1 true WO2023197615A1 (zh) 2023-10-19

Family

ID=81416602

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/134959 WO2023197615A1 (zh) 2022-04-12 2022-11-29 一种具有造孔功能涂层的集流体、极片以及电池

Country Status (5)

Country Link
US (1) US20230327133A1 (zh)
EP (1) EP4261925A1 (zh)
JP (1) JP2023156226A (zh)
CN (1) CN114464816B (zh)
WO (1) WO2023197615A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114464816B (zh) * 2022-04-12 2022-07-12 瑞浦兰钧能源股份有限公司 一种具有造孔功能涂层的集流体、极片以及锂离子电池
CN116387449B (zh) * 2023-06-02 2023-10-27 宁德时代新能源科技股份有限公司 电极极片、电池单体、电池和用电装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105633350A (zh) * 2016-04-01 2016-06-01 深圳市沃特玛电池有限公司 一种多孔极片及其制备方法、锂离子电池
CN111129504A (zh) * 2020-01-17 2020-05-08 清华大学深圳国际研究生院 改性集流体的制备方法、改性集流体、电极片及锂电池
CN111732867A (zh) * 2020-06-29 2020-10-02 蜂巢能源科技有限公司 一种涂层浆料和涂层和锂离子电池及其用途
CN112216818A (zh) * 2019-07-11 2021-01-12 比亚迪股份有限公司 一种锂离子电池负极及其制备方法、锂离子电池和电池模组
CN113224314A (zh) * 2021-05-06 2021-08-06 中国科学院宁波材料技术与工程研究所 一种三维分级多孔集流体及其制备方法
CN114464816A (zh) * 2022-04-12 2022-05-10 瑞浦能源有限公司 一种具有造孔功能涂层的集流体、极片以及锂离子电池

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100682862B1 (ko) * 2005-01-11 2007-02-15 삼성에스디아이 주식회사 전기 화학 전지용 전극, 그 제조 방법 및 이를 채용한전기 화학 전지
CN102034981A (zh) * 2010-10-26 2011-04-27 东莞新能源科技有限公司 一种锂离子电池负极用集流体
CN102655229B (zh) 2012-03-19 2014-11-05 宁德新能源科技有限公司 一种锂离子电池膜片的造孔方法
CN102931378B (zh) * 2012-10-09 2016-01-20 东莞市创明电池技术有限公司 锂离子电池电极及其制备方法、锂离子电池
CN104157827A (zh) * 2013-05-14 2014-11-19 深圳华粤宝电池有限公司 锂离子电池负极片及其制备方法
CN105845872A (zh) * 2016-05-04 2016-08-10 合肥国轩高科动力能源有限公司 一种用于粘结锂电池隔膜与极片的涂层浆料及其制备方法
KR101984723B1 (ko) * 2016-09-07 2019-05-31 주식회사 엘지화학 리튬 전극용 다공성 집전체 및 이를 포함하는 리튬 전극
CN108511689B (zh) * 2017-04-05 2020-12-15 万向一二三股份公司 一种含有导电涂层的锂离子电池正极片及其制备方法
CN110098409B (zh) * 2018-01-30 2021-11-02 宁德时代新能源科技股份有限公司 一种二次电池集流体及使用该集流体的二次电池
CN109167020B (zh) * 2018-09-11 2021-03-30 天津市捷威动力工业有限公司 一种具有高能量密度的多孔锂离子极片及其制备方法及锂离子电池
CN109301168A (zh) * 2018-10-27 2019-02-01 山东华亿比科新能源股份有限公司 一种锂离子电池用二次雾化造孔方法
CN109509877B (zh) * 2018-11-30 2020-12-11 清华大学深圳研究生院 碳包覆多孔金属涂层集流体、制备方法及锂电池
JP7131472B2 (ja) * 2019-04-25 2022-09-06 トヨタ自動車株式会社 セパレータ付き電極板の製造方法及び電池の製造方法
PL430517A1 (pl) * 2019-07-08 2021-01-11 Uniwersytet Warszawski Ogniwo litowo-jonowe zawierające trójwymiarowe kolektory prądowe i sposób wytwarzania elektrod do tego ogniwa
CN110957470B (zh) * 2019-12-06 2021-05-18 华中科技大学 具有垂直孔道结构的锂离子电池极片的制备方法及产品
WO2021138814A1 (zh) 2020-01-07 2021-07-15 宁德新能源科技有限公司 电化学装置和包含所述电化学装置的电子装置
CN111725479B (zh) * 2020-07-16 2021-08-03 深圳市信宇人科技股份有限公司 锂离子电池极片及其制备方法
CN112103509B (zh) * 2020-08-20 2023-06-06 欣旺达电动汽车电池有限公司 正极集流体、正极片、锂离子电池及电池模组

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105633350A (zh) * 2016-04-01 2016-06-01 深圳市沃特玛电池有限公司 一种多孔极片及其制备方法、锂离子电池
CN112216818A (zh) * 2019-07-11 2021-01-12 比亚迪股份有限公司 一种锂离子电池负极及其制备方法、锂离子电池和电池模组
CN111129504A (zh) * 2020-01-17 2020-05-08 清华大学深圳国际研究生院 改性集流体的制备方法、改性集流体、电极片及锂电池
CN111732867A (zh) * 2020-06-29 2020-10-02 蜂巢能源科技有限公司 一种涂层浆料和涂层和锂离子电池及其用途
CN113224314A (zh) * 2021-05-06 2021-08-06 中国科学院宁波材料技术与工程研究所 一种三维分级多孔集流体及其制备方法
CN114464816A (zh) * 2022-04-12 2022-05-10 瑞浦能源有限公司 一种具有造孔功能涂层的集流体、极片以及锂离子电池

Also Published As

Publication number Publication date
CN114464816B (zh) 2022-07-12
EP4261925A1 (en) 2023-10-18
JP2023156226A (ja) 2023-10-24
CN114464816A (zh) 2022-05-10
US20230327133A1 (en) 2023-10-12

Similar Documents

Publication Publication Date Title
CN105958008B (zh) 一种锂离子电池用复合正极片、制备方法及锂离子电池
CN110137485B (zh) 一种含有表面修饰膜的硅负极材料的制备方法
CN106654177B (zh) 一种干法制备电池电容复合电极的方法
CN112397682B (zh) 一种补锂的负极极片及其锂离子电池
CN107978732B (zh) 极片及电池
WO2023197615A1 (zh) 一种具有造孔功能涂层的集流体、极片以及电池
CN104332588B (zh) 一种高安全性锂离子电池负极极片、制备方法和应用
CN109980290B (zh) 一种混合固液电解质锂蓄电池
CN104078246A (zh) 一种锂离子电池电容器
CN110247009A (zh) 一种防过充隔膜及其制备方法和锂离子电池
CN115395116B (zh) 一种钠离子电池正极极片及其制备方法、钠离子电池
CN109428051A (zh) 锂离子电池及其正极片
CN109859951A (zh) 一种碳基复合负极材料及其制备方法以及一种化学电源及其制备方法
EP4362123A1 (en) Negative electrode sheet and battery applying same
CN115275109A (zh) 一种长循环磷酸铁锂厚电极及其制备方法和锂离子电池
CN108598442A (zh) 一种硅基锂离子电池负极材料的制备方法以及由此得到的硅基锂离子电池负极材料
CN108417822A (zh) 一种21700锂离子电池及其制备方法
CN110380057A (zh) 一种耐过充锂离子电池
CN105226235B (zh) 一种凝胶聚合物包覆的锂离子电池正极及其制备方法
CN108470877A (zh) 一种18650锂离子电池及其制备方法
CN105406029A (zh) 锂离子电池正极极片或负极极片的制备方法
CN116014355A (zh) 一种预钠化隔膜及其制备方法
CN217239504U (zh) 锂离子电池正极极片和锂离子电池
CN217239505U (zh) 锂离子电池正极极片和锂离子电池
CN113013392B (zh) 一种电极极片及其制备方法和应用

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: 22937247

Country of ref document: EP

Kind code of ref document: A1