WO2022205110A1 - 电化学装置和电子装置 - Google Patents

电化学装置和电子装置 Download PDF

Info

Publication number
WO2022205110A1
WO2022205110A1 PCT/CN2021/084501 CN2021084501W WO2022205110A1 WO 2022205110 A1 WO2022205110 A1 WO 2022205110A1 CN 2021084501 W CN2021084501 W CN 2021084501W WO 2022205110 A1 WO2022205110 A1 WO 2022205110A1
Authority
WO
WIPO (PCT)
Prior art keywords
coating
reinforcement
electrochemical device
coating layer
active material
Prior art date
Application number
PCT/CN2021/084501
Other languages
English (en)
French (fr)
Inventor
李志愿
李娅洁
Original Assignee
宁德新能源科技有限公司
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 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to CN202180004994.2A priority Critical patent/CN114270561B/zh
Priority to PCT/CN2021/084501 priority patent/WO2022205110A1/zh
Publication of WO2022205110A1 publication Critical patent/WO2022205110A1/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
    • 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
    • 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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/581—Devices or arrangements for the interruption of current in response to temperature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of electrochemical energy storage, in particular to electrochemical devices and electronic devices.
  • a positive temperature coefficient (PTC) resistance sheet can usually be added to the external circuit to cut off the current when the temperature of the electrochemical device rises to make the electrochemical device open circuit; decrease, the film breaking temperature increases, and the thermal shrinkage decreases to reduce the internal short circuit of the electrochemical device; or prepare a PTC hybrid electrode or a PTC wrapped electrode.
  • PTC positive temperature coefficient
  • the response of adding a PTC resistor sheet to the external circuit is slow and not timely, and it only works when the side reaction generates more heat; regarding the structure or material modification of the isolation film, due to the limited heat resistance of the isolation film material itself, closed pores and broken holes The membrane temperature gap is small, the membrane rupture cannot be suppressed at high temperature, and the safety performance of the electrochemical device is limited.
  • the PTC hybrid electrode needs to increase the amount of conductive agent and polymer, which affects the energy density of the electrochemical device.
  • the PTC-wrapped electrode is at the material level. It is difficult to process, and it is difficult to achieve uniform packaging, which affects the properties of the material itself. Therefore, further improvements are still expected.
  • Some embodiments of the present application provide an electrochemical device including an electrode including a current collector, a first coating layer, a second coating layer, and an active material layer, wherein the first coating layer is located between the current collector and the first coating layer. Between the two coatings, the second coating is located between the first coating and the active material layer.
  • the first coating includes a positive temperature coefficient material and a first conductive agent
  • the second coating includes a second conductive agent, a binder, and a reinforcement.
  • the reinforcement includes lithium iron phosphate, lithium iron phosphate, silicon dioxide, titanium dioxide, aluminum oxide, boehmite, magnesium oxide, zirconium oxide, titanium dioxide, silicon carbide, boron carbide, barium carbonate, At least one of potassium titanate, barium sulfate, vanadium trioxide, polyether ether ketone, polyamide or cellulose powder.
  • the mass percentage content of the reinforcement is 40% to 98%, preferably 60% to 80%, based on the total mass of the second coating.
  • the reinforcement has a Vickers hardness of 600 to 2000, preferably 800 to 1500.
  • the particle sphericity of the reinforcement is in the range of 0.5 to 1, preferably 0.7 to 1.
  • the Dv50 of the reinforcement is 0.05 ⁇ m to 2 ⁇ m, preferably 0.2 ⁇ m to 1 ⁇ m.
  • the thickness of the second coating is 0.2 ⁇ m to 5 ⁇ m. In some embodiments, the mass ratio of the second conductive agent, the binder and the reinforcement in the second coating is (1 to 20):(1 to 20):(60 to 98).
  • the binder includes polyvinyl alcohol, polyacrylic acid, polyethylene glycol, polyethylene oxide, carboxymethyl cellulose salt, polyacrylamide, polymaleic anhydride, polyquaternary ammonium salt, starch, At least one of chitosan, pectin, polyacrylate, polyvinyl chloride, polyvinyl chloride, natural rubber latex, neoprene latex, nitrile latex, styrene-butadiene latex or styrene-acrylic latex.
  • the PTC material satisfies at least one of the following conditions: the PTC material has a melting point of 115°C to 180°C; the PTC material includes polyethylene (PE), polypropylene (PP), polychlorinated Ethylene, polystyrene, polytetrafluoroethylene, polybutylene terephthalate, polyimide, polyvinyl alcohol, polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), poly At least one of acrylonitrile, polyoxymethylene, ethylene-vinyl acetate copolymer or polyethylene terephthalate; the mass content of the positive temperature coefficient material in the first coating layer is 60% to 98%. In some embodiments, the thickness of the first coating is 0.5 ⁇ m to 12 ⁇ m.
  • the first conductive agent and the second conductive agent each independently include at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, carbon fibers, aluminum powder, nickel powder, or gold powder.
  • the mass content of the first conductive agent in the first coating is 2% to 40%.
  • Embodiments of the present application also provide an electronic device, including the above electrochemical device.
  • Embodiments of the present application provide a first coating layer and a second coating layer between the current collector and the active material layer, wherein the first coating layer includes a positive temperature coefficient material and a first conductive agent, the positive temperature coefficient material at high temperature.
  • the resistance increases, cutting off electron transport and preventing short-circuiting of the electrochemical device.
  • the second coating layer can protect the first coating layer, and the second coating layer includes reinforcements, which can reduce the damage of the first coating layer during the coating of the active material layer and/or the cold pressing of the pole piece to avoid active
  • the active material in the material layer is embedded in the first coating layer and is in direct contact with the current collector, so that the first coating layer remains intact and ensures that the first coating layer cuts off the electronic path at high temperature, thereby improving the thermal runaway of the electrochemical device.
  • an electrochemical device including an electrode including a current collector, a first coating layer, a second coating layer, and an active material layer, wherein the first coating layer is located between the current collector and the first coating layer. Between the two coatings, the second coating is located between the first coating and the active material layer. It should be understood that the first coating, the second coating and the active material layer can all be located on one or both sides of the current collector.
  • the first coating includes a positive temperature coefficient material and a first conductive agent.
  • the resistance value can show a step increase. Therefore, when the temperature of the first coating layer increases due to a short circuit in the electrochemical device, the positive temperature coefficient material can melt and expand, cutting off the electron transport of the first coating layer, increasing the resistance of the first coating layer, and protecting it effect.
  • the second coating includes a second conductive agent, a binder, and a reinforcement.
  • the second coating can protect the first coating, and the reinforcements in the second coating can reduce the exposure of the first coating to the active material layer coating and/or cold pressing of the pole piece. The destruction of the first coating keeps the first coating intact and ensures the realization of the function of the first coating to cut off the electronic path at high temperature, thereby improving the thermal runaway of the electrochemical device. If there is no second coating, during the cold pressing process, the edges and corners of the active material particles in the active material layer will easily damage or even break down the first coating, making it difficult for the first coating to cut off electron transport at high temperature. Function. The presence of the reinforcements in the second coating can prevent the first coating from being pierced by the active material particles during the cold pressing process, thereby protecting the first coating.
  • the positive temperature coefficient material includes a polymer. At high temperature (eg, greater than 100° C.), the polymer expands and the conductive network between the particles of the first conductive agent is destroyed, thereby cutting off electron transport, so that the first coating has a PTC effect.
  • the positive temperature coefficient material includes polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polybutylene terephthalate, polyimide, polyvinyl alcohol, polyvinyl At least one of methyl methacrylate, polyvinylidene fluoride, polyacrylonitrile or polyethylene terephthalate.
  • the positive temperature coefficient material has a melting point of 115°C to 180°C. If the melting point of the positive temperature coefficient material is lower than 115°C, it will affect the coating process of the pole piece, and if the melting point is higher than 180°C, it is difficult to improve the safety performance.
  • the mass content of the positive temperature coefficient material is 60% to 98% based on the total mass of the first coating. In some embodiments, the mass content of the first conductive agent is 2% to 40% based on the total mass of the first coating. If the mass content of the positive temperature coefficient material in the first coating layer is greater than 98%, when the mass content of the first conductive agent is less than 2%, the larger resistance of the first coating layer itself will affect the performance of the electrochemical device. If the mass content of the positive temperature coefficient material in the first coating is less than 60%, when the mass content of the first conductive agent is higher than 40%, it is difficult for the first coating to have the PTC effect. In some embodiments, the mass content of the positive temperature coefficient material in the first coating is 80% to 95%.
  • the first coating has a strong PTC effect, and will not adversely affect the performance of the electrochemical device because the electrical conductivity is too weak.
  • the first conductive agent includes at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, carbon fibers, aluminum powder, nickel powder, or gold powder.
  • the thickness of the first coating is 0.5 ⁇ m to 12 ⁇ m. If the thickness of the first coating layer is too small, it is difficult to achieve the PTC protection effect. If the thickness of the first coating layer is too large, the energy density of the electrochemical device is adversely affected.
  • the second conductive agent includes at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, carbon fibers, aluminum powder, nickel powder, or gold powder.
  • the binder includes polyvinyl alcohol, polyacrylic acid, polyethylene glycol, polyethylene oxide, carboxymethyl cellulose salt, polyacrylamide, polymaleic anhydride, polyquaternary ammonium salt, starch, At least one of chitosan, pectin, polyacrylate, polyvinyl chloride, polyvinyl chloride, natural rubber latex, neoprene latex, nitrile latex, styrene-butadiene latex or styrene-acrylic latex.
  • binders can better bond the second conductive agent and the reinforcement together to form the second coating.
  • the above-mentioned binder is an aqueous solution type or an aqueous emulsion type, which avoids the compatibility between the second coating layer and the active material layer during the coating process of the active material layer (using solvent NMP).
  • the reinforcement includes lithium iron phosphate, lithium iron phosphate, silicon dioxide, titanium dioxide, aluminum oxide, boehmite, magnesium oxide, zirconium oxide, titanium dioxide, silicon carbide, boron carbide, barium carbonate, At least one of potassium titanate, barium sulfate, vanadium trioxide, polyether ether ketone, polyamide or powder.
  • the reinforcing body is included in the second coating layer, which can reduce the damage of the first coating layer during the coating of the active material layer and the cold pressing of the pole piece, and prevent the active material in the active material layer from being embedded in the first coating layer and in direct contact with the current collector, Leaving the first coating intact ensures that the first coating cuts off the electron path at high temperatures, thereby improving thermal runaway of the electrochemical device.
  • the mass content of the reinforcement in the second coating is 40% to 98%. If the mass content of the reinforcement in the second coating is too small, the protective effect that the reinforcement can play is relatively limited; if the mass content of the reinforcement in the second coating is too large, the electrical conductivity of the second coating will be limited. The performance and bonding effect can be affected, which in turn affects the performance of the electrochemical device.
  • the mass content of the reinforcement in the second coating is 60% to 98%. In some embodiments, the mass content of the reinforcement in the second coating is 60% to 80%. In some embodiments, the mass content of the second conductive agent in the second coating is 1% to 20%. In some embodiments, the mass content of the binder in the second coating is 1% to 20%.
  • the mass ratio of the second conductive agent, the binder and the reinforcement in the second coating is (1 to 20):(1 to 20):(60 to 98). In this way, the content of each component in the second coating reaches a good balance and achieves their respective functions. At this time, the reinforcing body can play a better protective effect on the first coating, and the binder can protect the second coating.
  • the conductive agent and the reinforcement are well bonded together, and the second conductive agent can impart suitable electrical conductivity to the second coating.
  • the reinforcement has a Vickers hardness of 600 to 2000. If the Vickers hardness of the reinforcement is too small, it will be easily damaged by the particles in the active material layer; but if the hardness of the reinforcement is too large, the high hardness of the reinforcement itself will cause the reinforcement to be embedded in the first coating layer during cold pressing. Destroying the integrity of the first coating will affect the PTC effect, and at the same time, high hardness will also cause the active material particles in contact with the reinforcement to be broken, affecting the battery performance.
  • the reinforcement has a Vickers hardness of 800 to 1500. At this time, the reinforcement can play a better protective effect.
  • the particle sphericity of the reinforcement ranges from 0.5 to 1. If the sphericity is too small, for example, less than 0.5, the angularity of the reinforcement is too large, and the protective effect of the first coating layer will be weaker than that of the reinforcement of spherical particles. In some embodiments, the particle sphericity of the reinforcement ranges from 0.7 to 1. In this way, the adverse effects of the edges and corners of the reinforcement on the protection effect can be basically eliminated.
  • the coverage of the second coating is more than 60%, so that a better protection effect can be achieved. If the coverage of the second coating is too small, the second coating is not covered during the cold pressing process.
  • the first coating layer of the layer will be in direct contact with the active material particles. Due to the polygonal structure of the active material particles, without the protection of the second coating layer, the cold pressing process is embedded in the first coating layer, so that the first coating layer is damaged, Affect PTC effect.
  • the coverage of the second coating is above 80%.
  • the thickness of the second coating is 0.2 ⁇ m to 5 ⁇ m. If the thickness of the second coating is less than 0.2 ⁇ m, the protective effect of the first coating is relatively limited; if the thickness of the second coating is greater than 5 ⁇ m, the resistance of the second coating is deteriorated on the one hand, and electricity is lost on the other hand. Energy density of chemical devices.
  • the Dv50 of the enhancer is 0.05 ⁇ m to 2 ⁇ m.
  • Dv50 refers to the particle size at which the volume distribution of the particles reaches 50%. If the Dv50 of the reinforcement is too small, it is not conducive to the uniform dispersion of the reinforcement in the second coating; if the Dv50 of the reinforcement is too large, the thickness of the second coating will increase, affecting the energy density. In some embodiments, the Dv50 of the enhancer is 0.2 ⁇ m to 1 ⁇ m. In this way, the uniform dispersion of the reinforcement can be ensured, and the thickness of the second coating layer can not be affected too much.
  • the active material layer is a positive electrode active material layer and includes a positive electrode active material.
  • the positive active material includes lithium cobalt oxide, lithium iron phosphate, lithium iron manganese phosphate, sodium iron phosphate, lithium vanadium phosphate, sodium vanadium phosphate, lithium vanadyl phosphate, sodium vanadyl phosphate, lithium vanadate, manganese At least one of lithium oxide, lithium nickelate, lithium nickel cobalt manganese oxide, lithium rich manganese based material or lithium nickel cobalt aluminate.
  • the positive electrode active material layer may further include a conductive agent.
  • the conductive agent in the positive active material layer may include at least one of conductive carbon black, Ketjen black, lamellar graphite, graphene, carbon nanotubes, or carbon fibers.
  • the positive electrode active material layer may further include a binder, and the binder in the positive electrode active material layer may include carboxymethyl cellulose (CMC), polyacrylic acid, polyvinylpyrrolidone, polyaniline, polyamide At least one of imine, polyamideimide, polysiloxane, styrene-butadiene rubber, epoxy resin, polyester resin, polyurethane resin or polyfluorene.
  • CMC carboxymethyl cellulose
  • the mass ratio of the positive electrode active material, the conductive agent, and the binder in the positive electrode active material layer may be (80 to 99):(0.1 to 10):(0.1 to 10).
  • the thickness of the cathode active material layer may be 10 ⁇ m to 500 ⁇ m. It should be understood that the above description is only an example, and the positive electrode active material layer of the positive electrode may adopt any other suitable material, thickness and mass ratio.
  • the current collector of the positive electrode can use Al foil, of course, other current collectors commonly used in the art can also be used.
  • the thickness of the current collector of the positive electrode may be 1 ⁇ m to 200 ⁇ m.
  • the positive electrode active material layer may be coated only on a partial area of the current collector of the positive electrode.
  • the active material layer is a negative electrode active material layer.
  • the anode active material layer includes an anode active material, and the anode active material may include at least one of graphite, hard carbon, silicon, silicon oxide, or silicone.
  • a conductive agent and a binder may also be included in the anode active material layer.
  • the conductive agent in the negative active material layer may include at least one of conductive carbon black, Ketjen black, lamellar graphite, graphene, carbon nanotubes, or carbon fibers.
  • the binder in the negative active material layer may include carboxymethyl cellulose (CMC), polyacrylic acid, polyvinylpyrrolidone, polyaniline, polyimide, polyamideimide, polysilicon At least one of oxane, styrene-butadiene rubber, epoxy resin, polyester resin, polyurethane resin or polyfluorene.
  • the mass ratio of the anode active material, the conductive agent, and the binder in the anode active material layer may be (80 to 98):(0.1 to 10):(0.1 to 10). It should be understood that the above are only examples and any other suitable materials and mass ratios may be employed.
  • the current collector of the negative electrode can be at least one of copper foil, nickel foil or carbon-based current collector.
  • the release membrane includes at least one of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polyimide, or aramid.
  • the polyethylene includes at least one selected from high density polyethylene, low density polyethylene or ultra-high molecular weight polyethylene. Especially polyethylene and polypropylene, they have a good effect on preventing short circuits and can improve the stability of the battery through the shutdown effect.
  • the thickness of the isolation film is in the range of about 5 ⁇ m to 500 ⁇ m.
  • the surface of the separator may further include a porous layer, the porous layer is disposed on at least one surface of the substrate of the separator, the porous layer includes inorganic particles and a binder, and the inorganic particles are selected from alumina (Al 2 O 3 ), silicon oxide (SiO 2 ), magnesium oxide (MgO), titanium oxide (TiO 2 ), hafnium dioxide (HfO 2 ), tin oxide (SnO 2 ), plutonium dioxide (CeO 2 ), nickel oxide (NiO) ), zinc oxide (ZnO), calcium oxide (CaO), zirconium oxide (ZrO 2 ), yttrium oxide (Y 2 O 3 ), silicon carbide (SiC), boehmite, aluminum hydroxide, magnesium hydroxide, hydroxide At least one of calcium or barium sulfate.
  • alumina Al 2 O 3
  • silicon oxide SiO 2
  • magnesium oxide MgO
  • titanium oxide TiO 2
  • the pores of the isolation membrane have diameters in the range of about 0.01 ⁇ m to 1 ⁇ m.
  • the binder of the porous layer is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, polyamide At least one of vinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene or polyhexafluoropropylene.
  • the porous layer on the surface of the separator can improve the heat resistance, oxidation resistance and electrolyte wettability of the separator, and enhance the adhesion between the separator and the pole piece.
  • the electrode assembly of the electrochemical device is a wound electrode assembly, a stacked electrode assembly, or a folded electrode assembly.
  • the positive electrode and/or the negative electrode of the electrochemical device may be a multi-layer structure formed by winding or stacking, or may be a single-layer structure in which a single-layer positive electrode, a separator, and a single-layer negative electrode are stacked.
  • the electrochemical device includes a lithium-ion battery, although the present application is not so limited.
  • the electrochemical device may also include an electrolyte.
  • the electrolyte may be one or more of a gel electrolyte, a solid electrolyte, and an electrolytic solution, and the electrolytic solution includes a lithium salt and a non-aqueous solvent.
  • the lithium salt is selected from LiPF6, LiBF4 , LiAsF6, LiClO4 , LiB ( C6H5 ) 4 , LiCH3SO3 , LiCF3SO3 , LiN ( SO2CF3 ) 2 , LiC ( SO2CF3 ) 3 , LiSiF 6 , LiBOB or one or more of lithium difluoroborate.
  • LiPF 6 is chosen as the lithium salt because it has high ionic conductivity and can improve cycle characteristics.
  • the non-aqueous solvent may be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.
  • the carbonate compound may be a chain carbonate compound, a cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.
  • chain carbonate compounds are diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl carbonate Ethyl esters (MEC) and combinations thereof.
  • chain carbonate compounds are diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl carbonate Ethyl esters (MEC) and combinations thereof.
  • Examples of the cyclic carbonate compound are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylethylene carbonate (VEC), or a combination thereof.
  • fluorocarbonate compound examples include fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluorocarbonate Fluoroethylene, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-carbonate -Difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, or a combination thereof.
  • FEC fluoroethylene carbonate
  • 1,2-difluoroethylene carbonate 1,1-difluoroethylene carbonate
  • 1,1,2-trifluorocarbonate Fluoroethylene, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-carbonate -Difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate
  • carboxylate compounds are methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyrolactone, decolactone, Valerolactone, mevalonolactone, caprolactone, methyl formate, or a combination thereof.
  • ether compounds are dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxy Ethane, 2-methyltetrahydrofuran, tetrahydrofuran, or a combination thereof.
  • organic solvents examples include dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, methyl amide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, and phosphate esters or combinations thereof.
  • the positive electrode, the separator, and the negative electrode are wound or stacked in sequence to form electrode parts, and then packed into, for example, an aluminum-plastic film for encapsulation, injected with electrolyte, and formed into, Encapsulation, that is, to make a lithium-ion battery. Then, the performance test of the prepared lithium-ion battery was carried out.
  • electrochemical devices eg, lithium ion batteries
  • electrochemical devices eg, lithium ion batteries
  • Other methods commonly used in the art may be employed without departing from the disclosure of the present application.
  • Embodiments of the present application also provide electronic devices including the above electrochemical devices.
  • the electronic device in the embodiment of the present application is not particularly limited, and it may be used in any electronic device known in the prior art.
  • electronic devices may include, but are not limited to, notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, VCRs, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, assisted bicycles, bicycles, Lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large-scale household storage batteries and lithium-ion capacitors, etc.
  • Preparation of positive electrode using aluminum foil as the current collector of the positive electrode, uniformly coat the first coating slurry on the surface of the aluminum foil, the composition of the slurry is 90wt% polyvinylidene fluoride (PVDF) and 10wt% conductive carbon black, dry Afterwards, the first coating with a thickness of about 4 ⁇ m on one side (micrometer test) was obtained. Then a second coating is applied on the first coating. The composition of the slurry of the second coating is 85wt% boehmite, 8wt% conductive carbon black and 7wt% polyacrylic acid. After drying, a single-sided thickness of about 1 ⁇ m is obtained. Second coat (Micrometer test).
  • PVDF polyvinylidene fluoride
  • conductive carbon black dry Afterwards, the first coating with a thickness of about 4 ⁇ m on one side (micrometer test) was obtained. Then a second coating is applied on the first coating. The composition of the slurry of the second coating is 85
  • the positive electrode active material layer is coated on the second coating layer.
  • the positive electrode active material lithium cobalt oxide, the conductive agent conductive carbon black, and the binder polyacrylic acid are dissolved in N- In the methylpyrrolidone (NMP) solution, the slurry of the positive electrode active material layer was formed, and the slurry was coated on the second coating layer with a coating amount of 18.37 mg/cm 2 to obtain the positive electrode active material layer, which was dried, The positive electrode is obtained after cold pressing and cutting.
  • NMP N- In the methylpyrrolidone
  • the isolation film substrate is polyethylene (PE) with a thickness of 8 ⁇ m, and 2 ⁇ m alumina ceramic layers are coated on both sides of the isolation film substrate, and finally, 2.5 ⁇ m alumina ceramic layers are coated on both sides of the coated ceramic layer. mg/cm 2 binder polyvinylidene fluoride (PVDF), dried.
  • PE polyethylene
  • PVDF polyvinylidene fluoride
  • EC ethylene carbonate
  • PC propylene carbonate
  • Preparation of lithium ion battery stack the positive electrode, the separator and the negative electrode in sequence, so that the separator is placed between the positive electrode and the negative electrode for isolation, and then the electrode assembly is obtained by winding.
  • the electrode assembly is placed in the outer packaging aluminum-plastic film, and after dehydration at 80°C, the above electrolyte is injected and packaged, and the lithium ion battery is obtained through the process of forming, degassing, and trimming.
  • Use Yuanneng Technology BER1200 pole piece resistance meter place the resistance meter in a blast oven, place the 5cm*5cm positive pole in the resistance meter test fixture, and connect the pole piece to the multi-channel thermometer to test the actual pole piece. Temperature, the blast oven rises from room temperature to 185 °C at a heating rate of 5 °C/min, the resistance of the test pole piece changes between room temperature and 180 °C, and a point is output every 3 seconds to obtain a temperature-resistance curve. The calculated temperature is at 180 °C. The average value of resistance at ⁇ 0.3°C is the resistance at 180°C, and the average value of 5 pole pieces is taken.
  • the lithium-ion batteries were brought to SOC% at 0.5C CC, and 10 lithium-ion batteries were stored in a thermal shock box at 130°C and 150°C for 1 h or stopped immediately after thermal runaway. The surface temperature of the ion battery changes, and the experimental phenomenon is recorded. It is considered that the lithium ion battery smokes, catches fire, and explodes as a test failure.
  • Tables 1 and 2 show the respective parameters and evaluation results of Examples 1 to 6 and Comparative Examples 1 to 3, respectively.
  • the types and/or melting points of the PTC materials in Examples 2 to 6 are different from those in Example 1, and other parameters are the same as those in Example 1.
  • the positive electrode active material layer was directly coated on the positive electrode current collector without the first coating layer and the second coating layer; in Comparative Example 2, the positive electrode active material layer was directly coated on the first coating layer , without the second coating; in Comparative Example 3, the second coating contains no reinforcement particles, only 50 wt % conductive carbon black and 50 wt % polyacrylic acid.
  • the melting point of the positive temperature coefficient material is too low, the irreversible PTC effect may have been triggered during the film coating process, resulting in too high electrode resistance and affecting the performance of lithium-ion batteries.
  • the melting point of the positive temperature coefficient material is too high, the corresponding conductive network cut-off temperature will be higher, which is not conducive to early protection of the lithium-ion battery.
  • Tables 3 and 4 show the respective parameters and evaluation results of Examples 1 and 7 to 39.
  • the mass content of the positive temperature coefficient material in the first coating layer of Examples 7 to 11 is different from that of Example 1.
  • the thickness of the first coating of Examples 12 to 15 was different from that of Example 1.
  • the types of reinforcement particles of Examples 16 to 19 were different from those of Example 1, and the Vickers hardness of the particles was also different.
  • the mass content of the reinforcement particles in the second coatings of Examples 20 to 23 was different from that of Example 1.
  • the sphericity of the reinforcement particles in the second coating of Examples 24 to 27 was different from that of Example 1.
  • the coverage of the second coating of Examples 28 to 31 was different from that of Example 1.
  • the Dv50 of the reinforcement particles in the second coating of Examples 32 to 35 was different from that of Example 1.
  • the thickness of the second coating of Examples 36 to 39 was different from that of Example 1.
  • the mass content of the positive temperature coefficient material is reduced, the conductive network composed of more first conductive agents is difficult to be disconnected at high temperature, and the PTC effect is weakened, that is, the resistance at 180°C is relative to the resistance at 150°C. Increase the multiplier to decrease.
  • the PTC effect can be obtained by using reinforcing particles of suitable hardness.
  • the resistance of the positive electrode at 150°C and 180°C varies depending on the reinforcement used.
  • the function of the reinforcement is to resist the damage of the main material to the first coating during the cold pressing process and maintain the integrity of the first coating. Therefore, the reinforcement needs to have high hardness to withstand the force of the active material during cold pressing and reduce cold pressure.
  • the role of the reinforcing body is to resist the damage of the first coating layer by the active material during the cold pressing process, maintain the integrity of the first coating layer, and at the same time, the reinforcing body itself cannot be damaged during the cold pressing process Therefore, the sphericity of the reinforcement body needs to be increased, the edges and corners of the reinforcement are reduced, the damage to the first coating during the cold pressing process is weakened, the integrity of the first coating is increased, and the PTC effect is enhanced.
  • the function of the second coating is to resist the damage of the first coating by the active material during the cold pressing process and maintain the integrity of the first coating, so the second coating needs to have high coverage
  • the damage of the active material to the first coating during cold pressing is reduced, the integrity of the first coating is increased, and the PTC effect is enhanced. If the coverage is too small, the PTC effect is weakened.

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)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请提供了电化学装置和电子装置。电化学装置包括电极，电极包括集流体、第一涂层、第二涂层和活性材料层，其中，第一涂层位于集流体和第二涂层之间，第二涂层位于第一涂层和活性材料层之间。第一涂层包括正温度系数材料和第一导电剂，第二涂层包括第二导电剂、粘结剂和增强体。本申请的实施例通过在集流体和活性材料层之间设置第一涂层和第二涂层，其中第一涂层中的正温度系数材料在高温下电阻增大，切断电子传输，防止电化学装置的短路。而第二涂层可以对第一涂层起到保护作用，确保第一涂层的性能的正常发挥。

Description

电化学装置和电子装置 技术领域
本申请涉及电化学储能领域，尤其涉及电化学装置和电子装置。
背景技术
随着电化学装置(例如，锂离子电池)的发展和进步，对其安全性能提出了越来越高的要求。而内部短路、过充等情况导致的大量放热是影响电化学装置的安全性能的重要因素。
为此，通常可以在外电路加入正温度系数(PTC)电阻片，在电化学装置温度升高时切断电流使电化学装置断路；或者对隔离膜进行结构或材料改性，使隔离膜闭孔温度下降，破膜温度升高，热收缩减小来减少电化学装置的内部短路；或者制备PTC混合电极或PTC包裹电极。然而，在外电路加入PTC电阻片的响应缓慢，不及时，在副反应产热较多时才起作用；关于隔离膜的结构或材料改性，由于隔离膜材料本身耐热性有限，闭孔与破膜温度差距小，高温破膜无法抑制，对电化学装置的安全性能改善有限；另外，PTC混合电极需增加导电剂与聚合物的量，影响电化学装置的能量密度，PTC包裹电极在材料层面加工困难，难以做到包裹均匀，影响材料本身性质。因此，仍期待进一步的改进。
发明内容
本申请的一些实施例提供了一种电化学装置，电化学装置包括电极，电极包括集流体、第一涂层、第二涂层和活性材料层，其中，第一涂层位于集流体和第二涂层之间，第二涂层位于第一涂层和活性材料层之间。第一涂层包括正温度系数材料和第一导电剂，第二涂层包括第二导电剂、粘结剂和增强体。
在一些实施例中，增强体包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮、聚酰胺或纤维素粉中的至少一种。
在一些实施例中，基于第二涂层的总质量，增强体的质量百分含量为40％至98％，优选为60％至80％。
在一些实施例中，增强体的维氏硬度为600至2000，优选为800至1500。
在一些实施例中，增强体的颗粒球形度范围在0.5至1，优选为0.7至1。
在一些实施例中，增强体的Dv50为0.05μm至2μm，优选为0.2μm至1μm。
在一些实施例中，第二涂层的厚度为0.2μm至5μm。在一些实施例中，第二涂层中的第二导电剂、粘结剂和增强体的质量比为(1至20)∶(1至20)∶(60至98)。在一些实施例中，粘结剂包括聚乙烯醇、聚丙烯酸、聚乙二醇、聚环氧乙烯、羧甲基纤维素盐、聚丙烯酰胺、聚马来酸酐、聚季胺盐、淀粉、壳聚糖、果胶、聚丙烯酸酯、聚氯醋、聚氯乙烯、天然橡胶乳液、氯丁乳液、丁腈乳液、丁苯乳液或苯丙乳液中的至少一种。
在一些实施例中，正温度系数材料满足以下条件中的至少一个：正温度系数材料的熔点为115℃至180℃；正温度系数材料包括聚乙烯(PE)、聚丙烯(PP)、聚氯乙烯、聚苯乙烯、聚四氟乙烯、聚对苯二甲酸丁二醇酯、聚酰亚胺、聚乙烯醇、聚甲基丙烯酸甲酯(PMMA)、聚偏二氟乙烯(PVDF)、聚丙烯腈、聚甲醛、乙烯-醋酸乙烯共聚物或聚对苯二甲酸乙二醇酯中的至少一种；第一涂层中的正温度系数材料的质量含量为60％至98％。在一些实施例中，第一涂层的厚度为0.5μm至12μm。
在一些实施例中，第一导电剂和第二导电剂各自独立地包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。在一些实施例中，第一涂层中的第一导电剂的质量含量为2％至40％。
本申请的实施例还提供了一种电子装置，包括上述电化学装置。
本申请的实施例通过在集流体和活性材料层之间设置第一涂层和第二涂层，其中第一涂层包括正温度系数材料和第一导电剂，在高温下正温度系数材料的电阻增大，切断电子传输，防止电化学装置的短路。而第二涂层可以对第一涂层起到保护作用，第二涂层包括增强体，可以减弱第一涂层在活性 材料层涂覆和/或极片冷压期间受到的破坏，避免活性材料层中活性物质嵌入第一涂层并与集流体直接接触，使第一涂层保持完整，确保第一涂层在高温下切断电子通路，从而改善电化学装置的热失控。
具体实施方式
下面的实施例可以使本领域技术人员更全面地理解本申请，但不以任何方式限制本申请。
本申请的一些实施例提供了一种电化学装置，电化学装置包括电极，电极包括集流体、第一涂层、第二涂层和活性材料层，其中，第一涂层位于集流体和第二涂层之间，第二涂层位于第一涂层和活性材料层之间。应该理解，第一涂层、第二涂层和活性材料层均可以位于集流体的一侧或两侧上。
在一些实施例中，第一涂层包括正温度系数材料和第一导电剂。正温度系数材料在温度升高时，电阻值可以呈现出阶跃性的增大。因此，在电化学装置由于短路等引起第一涂层的温度升高时，正温度系数材料可以发生熔融膨胀，切断第一涂层的电子传输，第一涂层的电阻增大，起到保护作用。
在一些实施例中，第二涂层包括第二导电剂、粘结剂和增强体。在一些实施例中，第二涂层可以对第一涂层起到保护作用，第二涂层中的增强体可以减弱第一涂层在活性材料层涂覆和/或极片冷压期间受到的破坏，使第一涂层保持完整，确保第一涂层在高温下切断电子通路的功能的实现，从而改善电化学装置的热失控。如果不存在第二涂层，则在冷压过程中，活性材料层中的活性材料颗粒的棱角容易破坏甚至击穿第一涂层，使得第一涂层较难实现在高温下切断电子传输的功能。第二涂层中的增强体的存在可以避免第一涂层在冷压过程中被活性材料颗粒刺穿，起到对第一涂层的保护作用。
在一些实施例中，正温度系数材料包括聚合物。在高温下(例如，大于100℃)，聚合物膨胀，第一导电剂的颗粒之间的导电网络被破坏，从而切断电子传输，使得第一涂层具有PTC效应。在一些实施例中，正温度系数材料包括聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、聚四氟乙烯、聚对苯二甲酸丁二醇酯、聚酰亚胺、聚乙烯醇、聚甲基丙烯酸甲酯、聚偏二氟乙烯、聚丙烯腈或聚对苯二甲酸乙二醇酯中的至少一种。在一些实施例中，正温度系数材 料的熔点为115℃至180℃。正温度系数材料的熔点低于115℃会影响极片涂布过程，而熔点高于180℃则很难起到改善安全性能的效果。
在一些实施例中，基于第一涂层的总质量，正温度系数材料的质量含量为60％至98％。在一些实施例中，基于第一涂层的总质量，第一导电剂的质量含量为2％至40％。如果第一涂层中的正温度系数材料的质量含量大于98％，则使得第一导电剂的质量含量低于2％时，第一涂层本身较大的电阻会影响电化学装置的性能。如果第一涂层中的正温度系数材料的质量含量小于60％，则第一导电剂的质量含量高于40％时，此时第一涂层很难有PTC效应。在一些实施例中，第一涂层中的正温度系数材料的质量含量为80％至95％。此时，第一涂层具有较强的PTC效应，又不会因为导电性太弱而不利地影响电化学装置的性能。在一些实施例中，第一导电剂包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。
在一些实施例中，第一涂层的厚度为0.5μm至12μm。如果第一涂层的厚度太小，则难以起到PTC保护效果。如果第一涂层的厚度太大，则不利地影响电化学装置的能量密度。
在一些实施例中，第二导电剂包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。在一些实施例中，粘结剂包括聚乙烯醇、聚丙烯酸、聚乙二醇、聚环氧乙烯、羧甲基纤维素盐、聚丙烯酰胺、聚马来酸酐、聚季胺盐、淀粉、壳聚糖、果胶、聚丙烯酸酯、聚氯醋、聚氯乙烯、天然橡胶乳液、氯丁乳液、丁腈乳液、丁苯乳液或苯丙乳液中的至少一种。这些粘结剂可以较好地将第二导电剂和增强体粘结在一起，形成第二涂层。另外，上述粘结剂为水溶液型或水乳液型的，避免了在活性材料层(采用溶剂NMP)的涂布过程中第二涂层和活性材料层之间的相溶。
在一些实施例中，增强体包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮、聚酰胺或粉中的至少一种。第二涂层中包括增强体，可以减弱第一涂层在活性材料层涂覆与极片冷压期间受到的破坏，避免活性材料层中活性物质嵌入第一涂层并与集流体直 接接触，使第一涂层保持完整，确保第一涂层在高温下切断电子通路，从而改善电化学装置的热失控。
在一些实施例中，第二涂层中的增强体的质量含量为40％至98％。如果第二涂层中的增强体的质量含量太小，则增强体能够起到的保护作用相对受限；如果第二涂层中的增强体的质量含量太大，则第二涂层的导电性能和粘结效果会受到影响，进而影响电化学装置的性能。在一些实施例中，第二涂层中的增强体的质量含量为60％至98％。在一些实施例中，第二涂层中的增强体的质量含量为60％至80％。在一些实施例中，第二涂层中的第二导电剂的质量含量为1％至20％。在一些实施例中，第二涂层中的粘结剂的质量含量为1％至20％。在一些实施例中，第二涂层中的第二导电剂、粘结剂和增强体的质量比为(1至20)∶(1至20)∶(60至98)。如此，第二涂层中的各个组分的含量达到一个较好的平衡，实现各自的功能，此时增强体可以对第一涂层起到较好的保护作用，粘结剂可以将第二导电剂和增强体较好地粘结在一起，而第二导电剂可以赋予第二涂层合适的导电性能。
在一些实施例中，增强体的维氏硬度为600至2000。如果增强体的维氏硬度太小，则容易被活性材料层中的颗粒破坏；但增强体的硬度若极大，则增强体本身的高硬度反而会使冷压时嵌入第一涂层中、破坏第一涂层的完整性，影响PTC效应，同时高硬度也会造成与增强体接触的活性材料颗粒破碎，影响电池性能。在一些实施例中，增强体的维氏硬度为800至1500。此时，增强体能够起到较好的保护效果。
在一些实施例中，增强体的颗粒球形度范围在0.5至1。如果球形度太小，例如，小于0.5，则增强体的棱角过多，相对于球形颗粒的增强体，对第一涂层的保护效果会弱一些。在一些实施例中，增强体的颗粒球形度范围在0.7至1。如此，基本可以消除增强体的棱角对保护效果的不利影响。
在一些实施例中，第二涂层的覆盖度在60％以上，如此可以起到较好的保护效果，如果第二涂层覆盖度太小，则在冷压过程中，未覆盖第二涂层的第一涂层会与活性材料颗粒直接接触，由于活性材料颗粒的多棱角结构，在无第二涂层保护时，冷压过程嵌入第一涂层中，使第一涂层受到破坏，影响PTC效果。在一些实施例中，第二涂层覆盖度在80％以上。
在一些实施例中，第二涂层的厚度为0.2μm至5μm。如果第二涂层的厚度低于0.2μm，则对第一涂层的保护作用相对受限；如果第二涂层的厚度大于5μm，一方面恶化第二涂层的电阻，另一方面损失电化学装置的能量密度。
在一些实施例中，增强体的Dv50为0.05μm至2μm。Dv50是指颗粒的体积分布达到50％所对应的颗粒粒径。如果增强体的Dv50太小，则不利于增强体在第二涂层中的均匀分散；如果增强体的Dv50太大，会使得第二涂层厚度增加，影响能量密度。在一些实施例中，增强体的Dv50为0.2μm至1μm。如此，既可以确保增强体的均匀分散，也可以不对第二涂层的厚度产生过多影响。
在一些实施例中，在正极包括上述结构时，活性材料层为正极活性材料层，并且包括正极活性材料。在一些实施例中，正极活性材料包括钴酸锂、磷酸铁锂、磷酸锰铁锂、磷酸铁钠、磷酸钒锂、磷酸钒钠、磷酸钒氧锂、磷酸钒氧钠、钒酸锂、锰酸锂、镍酸锂、镍钴锰酸锂、富锂锰基材料或镍钴铝酸锂中的至少一种。在一些实施例中，正极活性材料层还可以包括导电剂。在一些实施例中，正极活性材料层中的导电剂可以包括导电炭黑、科琴黑、片层石墨、石墨烯、碳纳米管或碳纤维中的至少一种。在一些实施例中，正极活性材料层还可以包括粘结剂，正极活性材料层中的粘结剂可以包括羧甲基纤维素(CMC)、聚丙烯酸、聚乙烯基吡咯烷酮、聚苯胺、聚酰亚胺、聚酰胺酰亚胺、聚硅氧烷、丁苯橡胶、环氧树脂、聚酯树脂、聚氯酯树脂或聚芴中的至少一种。在一些实施例中，正极活性材料层中的正极活性材料、导电剂和粘结剂的质量比可以为(80至99)∶(0.1至10)∶(0.1至10)。在一些实施例中，正极活性材料层的厚度可以为10μm至500μm。应该理解，以上所述仅是示例，正极的正极活性材料层可以采用任何其他合适的材料、厚度和质量比。
在一些实施例中，正极的集流体可以采用Al箔，当然，也可以采用本领域常用的其他集流体。在一些实施例中，正极的集流体的厚度可以为1μm至200μm。在一些实施例中，正极活性材料层可以仅涂覆在正极的集流体的部分区域上。
在一些实施例中，当负极包括上述结构时，活性材料层为负极活性材料层。在一些实施例中，负极活性材料层包括负极活性材料，负极活性材料可 以包括石墨、硬碳、硅、氧化亚硅或有机硅中的至少一种。在一些实施例中，负极活性材料层中还可以包括导电剂和粘结剂。在一些实施例中，负极活性材料层中的导电剂可以包括导电炭黑、科琴黑、片层石墨、石墨烯、碳纳米管或碳纤维中的至少一种。在一些实施例中，负极活性材料层中的粘结剂可以包括羧甲基纤维素(CMC)、聚丙烯酸、聚乙烯基吡咯烷酮、聚苯胺、聚酰亚胺、聚酰胺酰亚胺、聚硅氧烷、丁苯橡胶、环氧树脂、聚酯树脂、聚氯酯树脂或聚芴中的至少一种。在一些实施例中，负极活性材料层中的负极活性材料、导电剂和粘结剂的质量比可以为(80至98)∶(0.1至10)∶(0.1至10)。应该理解，以上所述仅是示例，可以采用任何其他合适的材料和质量比。在一些实施例中，负极的集流体可以采用铜箔、镍箔或碳基集流体中的至少一种。
在一些实施例中，隔离膜包括聚乙烯、聚丙烯、聚偏氟乙烯、聚对苯二甲酸乙二醇酯、聚酰亚胺或芳纶中的至少一种。例如，聚乙烯包括选自高密度聚乙烯、低密度聚乙烯或超高分子量聚乙烯中的至少一种。尤其是聚乙烯和聚丙烯，它们对防止短路具有良好的作用，并可以通过关断效应改善电池的稳定性。在一些实施例中，隔离膜的厚度在约5μm至500μm的范围内。
在一些实施例中，隔离膜表面还可以包括多孔层，多孔层设置在隔离膜的基材的至少一个表面上，多孔层包括无机颗粒和粘结剂，无机颗粒选自氧化铝(Al 2O 3)、氧化硅(SiO 2)、氧化镁(MgO)、氧化钛(TiO 2)、二氧化铪(HfO 2)、氧化锡(SnO 2)、二氧化钸(CeO 2)、氧化镍(NiO)、氧化锌(ZnO)、氧化钙(CaO)、氧化锆(ZrO 2)、氧化钇(Y 2O 3)、碳化硅(SiC)、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种。在一些实施例中，隔离膜的孔具有在约0.01μm至1μm的范围的直径。多孔层的粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、羧甲基纤维素钠、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟丙烯中的至少一种。隔离膜表面的多孔层可以提升隔离膜的耐热性能、抗氧化性能和电解质浸润性能，增强隔离膜与极片之间的粘结性。
在本申请的一些实施例中，电化学装置的电极组件为卷绕式电极组件、堆叠式电极组件或折叠式电极组件。在一些实施例中，电化学装置的正极和/或负极可以是卷绕或堆叠式形成的多层结构，也可以是单层正极、隔离膜、单层负极叠加的单层结构。
在一些实施例中，电化学装置包括锂离子电池，但是本申请不限于此。在一些实施例中，电化学装置还可以包括电解质。电解质可以是凝胶电解质、固态电解质和电解液中的一种或多种，电解液包括锂盐和非水溶剂。锂盐选自LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3、LiSiF 6、LiBOB或者二氟硼酸锂中的一种或多种。例如，锂盐选用LiPF 6，因为它具有高的离子导电率并可以改善循环特性。
非水溶剂可为碳酸酯化合物、羧酸酯化合物、醚化合物、其它有机溶剂或它们的组合。
碳酸酯化合物可为链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或其组合。
链状碳酸酯化合物的实例为碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)及其组合。所述环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)或者其组合。所述氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(FEC)、碳酸1，2-二氟亚乙酯、碳酸1，1-二氟亚乙酯、碳酸1，1，2-三氟亚乙酯、碳酸1，1，2，2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1，2-二氟-1-甲基亚乙酯、碳酸1，1，2-三氟-2-甲基亚乙酯、碳酸三氟甲基亚乙酯或者其组合。
羧酸酯化合物的实例为乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯、甲瓦龙酸内酯、己内酯、甲酸甲酯或者其组合。
醚化合物的实例为二丁醚、四甘醇二甲醚、二甘醇二甲醚、1，2-二甲氧基乙烷、1，2-二乙氧基乙烷、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四 氢呋喃或者其组合。
其它有机溶剂的实例为二甲亚砜、1，2-二氧戊环、环丁砜、甲基环丁砜、1，3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、甲酰胺、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯、和磷酸酯或者其组合。
在本申请的一些实施例中，以锂离子电池为例，将正极、隔离膜、负极按顺序卷绕或堆叠成电极件，之后装入例如铝塑膜中进行封装，注入电解液，化成、封装，即制成锂离子电池。然后，对制备的锂离子电池进行性能测试。
本领域的技术人员将理解，以上描述的电化学装置(例如，锂离子电池)的制备方法仅是实施例。在不背离本申请公开的内容的基础上，可以采用本领域常用的其他方法。
本申请的实施例还提供了包括上述电化学装置的电子装置。本申请实施例的电子装置没有特别限定，其可以是用于现有技术中已知的任何电子装置。在一些实施例中，电子装置可以包括，但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
下面列举了一些具体实施例和对比例以更好地对本申请进行说明，其中，采用锂离子电池作为示例。为了简单的目的，下面仅以正极包括上述结构作为示例。
实施例1
正极的制备：采用铝箔作为正极的集流体，在铝箔表面均匀的涂布第一涂层的浆料，浆料的组成为90wt％聚偏二氟乙烯(PVDF)和10wt％导电炭黑，干燥后得到单面厚度约4μm的第一涂层(万分尺测试)。随后在第一涂层上涂布第二涂层，第二涂层的浆料的组成为85wt％勃姆石、8wt％导电炭黑和7wt％聚丙烯酸，干燥后得到单面厚度约1μm的第二涂层(万分尺测试)。 然后在第二涂层上涂布正极活性材料层，具体地，将正极活性材料钴酸锂、导电剂导电炭黑、粘结剂聚丙烯酸按重量比98.2∶0.5∶1.3的比例溶于N-甲基吡咯烷酮(NMP)溶液中，形成正极活性材料层的浆料，将该浆料涂覆于第二涂层上，涂覆量为18.37mg/cm 2，得到正极活性材料层，经过干燥、冷压、裁切后得到正极。
负极的制备：将石墨，羧甲基纤维素钠(CMC)和粘结剂丁苯橡胶按重量比97.8∶1.3∶0.9的比例溶于去离子水中，形成负极浆料。采用10μm厚度铜箔作为负极的集流体，将负极浆料涂覆于负极的集流体上，涂覆量为9.3mg/cm 2，干燥，裁切后得到负极。
隔离膜的制备：隔离膜基材为8μm厚的聚乙烯(PE)，在隔离膜基材的两侧各涂覆2μm氧化铝陶瓷层，最后在涂布了陶瓷层的两侧各涂覆2.5mg/cm 2的粘结剂聚偏氟乙烯(PVDF)，烘干。
电解液的制备：在含水量小于10ppm的环境下，将LiPF 6加入非水有机溶剂(碳酸乙烯酯(EC)∶碳酸丙烯酯(PC)＝50∶50，重量比)，LiPF 6的浓度为1.15mol/L，混合均匀，得到电解液。
锂离子电池的制备：将正极、隔离膜、负极按顺序依次叠好，使隔离膜处于正极和负极中间起到隔离的作用，并卷绕得到电极组件。将电极组件置于外包装铝塑膜中，在80℃下脱去水分后，注入上述电解液并封装，经过化成，脱气，切边等工艺流程得到锂离子电池。
实施例和对比例是在实施例1的步骤的基础上进行参数变更，具体变更的参数如下面的表格所示。
下面描述本申请的各个参数的测试方法。
常温电阻测试：
取10片15cm长、5cm宽的正极，保证极片平整无打皱，在室温环境下，使用元能科技BER1200极片电阻仪，沿极片垂直方向测试单片极片12个不同位置电阻为极片电阻，取10片极片电阻的平均值。
PTC响应温度的测试：
使用元能科技BER1200极片电阻仪，将电阻仪置于鼓风烘箱中，5cm*5cm的正极置于电阻仪测试夹具中，极片与多路测温仪相连，用于测试极片的实 际温度，鼓风烘箱以5℃/min升温速率从室温升至185℃，测试极片在室温～180℃之间电阻变化，每3秒输出一个点，得到温度-电阻曲线，对曲线求导数得到d(电阻)/d(温度)-温度曲线，导数≥0.08ohm/℃的第一个点对应温度为PTC响应温度，取5片极片平均值。
150℃下的电阻测试：
使用元能科技BER1200极片电阻仪，将电阻仪置于鼓风烘箱中，5cm*5cm的正极置于电阻仪测试夹具中，极片与多路测温仪相连，用于测试极片的实际温度，鼓风烘箱以5℃/min升温速率从室温升至185℃，测试极片在室温～180℃之间电阻变化，每3秒输出一个点，得到温度-电阻曲线，计算温度在150±0.3℃时的电阻平均值为150℃下电阻，取5片极片测试平均值。
180℃下的电阻测试：
使用元能科技BER1200极片电阻仪，将电阻仪置于鼓风烘箱中，5cm*5cm的正极置于电阻仪测试夹具中，极片与多路测温仪相连，用于测试极片的实际温度，鼓风烘箱以5℃/min升温速率从室温升至185℃，测试极片在室温～180℃之间电阻变化，每3秒输出一个点，得到温度-电阻曲线，计算温度在180±0.3℃时的电阻平均值为180℃下电阻，取5片极片测试平均值。
锂离子电池热箱测试：
将锂离子电池以0.5C CC至荷电状态SOC％，每组取10颗锂离子电池在130℃与150℃热冲击箱中存放1h停止或者热失控后立刻停止，采集锂离子电池电压与锂离子电池表面温度变化，记录实验现象，认为锂离子电池冒烟、着火、爆炸为测试失败。
锂离子电池过充测试：
将锂离子电池以3C CC至5V、5V CV 2h，3C CC至6V、6V CV 2h，采集锂离子电池电压与锂离子电池表面温度变化，记录实验现象，认为锂离子电池冒烟、着火、爆炸为测试失败，每组每个测试条件取10颗锂离子电池进行测试。
维氏硬度测试方法：
取增强体颗粒，使用HX-1000显微硬度计测试单个颗粒3个位置硬度并取平均值为维氏硬度，测试12个颗粒维氏硬度取其平均值。
颗粒度测试方法：
取增强体颗粒，使用Mastersizer 3000测试颗粒度分布取Dv50数据，测试3次取平均值。
球形度测试方法：
取增强体颗粒，使用VISION 218-D颗粒图像工作站测试球形度，测试3次取平均值。
覆盖度测试方法：
取正极除去集流体与第一涂层，裁剪为尺寸10mm*10mm，使用KEYENCE VHX5000进行观察第二涂层面，放大倍数为500倍，自动测量面积模式计算覆盖度，取12片计算平均值。
表1和表2分别示出了实施例1至6和对比例1至3的各个参数和评估结果。其中，实施例2至6的正温度系数材料的种类和/或熔点与实施例1不同，其他参数与实施例1一致。在对比例1中，直接在正极集流体上涂布正极活性材料层，而没有第一涂层和第二涂层；在对比例2中，在第一涂层上方直接涂布正极活性材料层，而没有第二涂层；在对比例3中，第二涂层中没有增强体颗粒，仅包含50wt％导电炭黑和50wt％聚丙烯酸。
表1
Figure PCTCN2021084501-appb-000001
Figure PCTCN2021084501-appb-000002
通过比较实施例1至6和对比例1可知，在正极中不含有第一涂层和第二涂层中，正极没有PTC效应。通过比较实施例1至6和对比例2可知，在正极中不含有第二涂层中，正极没有PTC效应。通过比较实施例1至6和对比例3可知，在正极的第二涂层中没有增强体颗粒时，正极没有PTC效应，在高温下电阻没有明显的增大。
通过比较实施例1至6可知，采用熔点为115℃至180℃的正温度系数材料，可以使得具有第一涂层的正极具有PTC效应。另外，随着正温度系数材料的熔点的增大，PTC响应温度有增大的趋势，这是因为正温度系数材料的熔点越高，其对应的导电网络切断温度越高，PTC响应温度也越高。另外，150℃和180℃下的电阻有减小的趋势。此外，在正极的温度超过PTC响应温度时，正极的电阻呈现几倍的增大。另外，若正温度系数材料的熔点太低，则可能在膜片涂布过程中已经触发了不可逆的PTC效应，造成极片电阻太高，影响锂离子电池性能。而正温度系数材料的熔点太高，则对应的导电网络切断温度越高，不利于及早地对锂离子电池进行保护。
表3和表4示出了实施例1和7至39的各个参数和评估结果。其中，实施例7至11的第一涂层中的正温度系数材料的质量含量与实施例1不同。实施例12至15的第一涂层的厚度与实施例1不同。实施例16至19的增强体颗粒的种类与实施例1不同，同时颗粒的维氏硬度也不同。实施例20至23的第二涂层中的增强体颗粒的质量含量与实施例1不同。实施例24至27的第二涂层中的增强体颗粒球形度与实施例1不同。实施例28至31的第二涂层的覆盖度与实施例1不同。实施例32至35的第二涂层中的增强体颗粒的Dv50与实施例1不同。实施例36至39的第二涂层的厚度与实施例1不同。
Figure PCTCN2021084501-appb-000003
Figure PCTCN2021084501-appb-000004
Figure PCTCN2021084501-appb-000005
Figure PCTCN2021084501-appb-000006
Figure PCTCN2021084501-appb-000007
表4
Figure PCTCN2021084501-appb-000008
Figure PCTCN2021084501-appb-000009
通过比较实施例1、7至11可知，当第一涂层中的正温度系数材料的质量含量为60％至98％时，随着第一涂层中的正温度系数材料的质量含量的增大，正极的常温电阻开始较为稳定，之后有增大的趋势；PTC响应温度保持不变；150℃和180℃下的电阻有增大的趋势。正温度系数材料的质量含量增大，则第一导电剂的含量需下降，极片的常温电阻后续会升高。另外，正温度系数材料的质量含量减小，较多的第一导电剂所构成的导电网络很难在高温下断开，PTC效应减弱，即180℃下的电阻相对于150℃下的电阻的增大倍数减小。
通过比较实施例1、12至15可知，随着第一涂层的厚度的增大，正极的常温电阻有增大的趋势；PTC响应温度保持不变；150℃和180℃下的电阻有增大的趋势。第一涂层的厚度增大，高温下导电网络的切断程度更高，PTC效应更显著。另一方面，第一涂层的厚度增大，极片的总体厚度增大，对电 化学装置的能量密度会有所影响。然而，如果第一涂层的厚度太小，则会弱化PTC效应。
通过比较实施例1、16至19可知，采用合适硬度的增强体颗粒能获得PTC效应。另外，正极的150℃和180℃下的电阻根据采用的增强体的不同会有所变化。增强体的作用为抵抗冷压过程主材对第一涂层的破坏，保持第一涂层的完整性，因此增强体需有高的硬度，以在冷压时承受活性材料的力，减少冷压时活性材料对第一涂层的破坏，但增强体的硬度若极大，则其本身的高硬度反而会使冷压时嵌入第一涂层中、破坏第一涂层的完整性，影响PTC效应，同时高硬度也会造成与增强体接触的活性材料颗粒破碎，影响性能。
通过比较实施例1、20至23可知，随着第二涂层中的增强体的质量含量的增大，正极的常温电阻有增大的趋势，这是因为第二涂层中的增强体的质量含量增大，第二导电剂的质量含量需下降，从而常温电阻增大；PTC响应温度保持不变；150℃和180℃下的电阻有增大的趋势。增强体颗粒的质量含量增大，对第一涂层的保护程度增加，使第一涂层在冷压过程中受到的破坏减弱，第一涂层的完整性增强。但是如果增强体的质量含量太小，则PTC效应减弱。
通过比较实施例1、24至27可知，增强体的作用为抵抗冷压过程活性材料对第一涂层的破坏，保持第一涂层的完整性，同时增强体在冷压过程中本身不能破坏第一涂层，因此需使增强体球形度增加，则其棱角减少，冷压过程中对第一涂层的破坏减弱，使第一涂层的完整性增加，PTC效应增强。
通过比较实施例1、28至31可知，第二涂层的作用为抵抗冷压过程活性材料对第一涂层的破坏，保持第一涂层的完整性，因此第二涂层需有高覆盖度，以在冷压时承受活性材料的力，减少冷压时活性材料对第一涂层的破坏，使第一涂层的完整性增加，PTC效应增强。如果覆盖度太小，则PTC效应减弱。
通过比较实施例1、32至35可知，增强体颗粒较大时，使第二涂层厚度增加，导致极片厚度增加影响能量密度，同时增强体的大颗粒使第二涂 层中其致密度下降，抵抗冷压过程中活性材料对第一涂层破坏的效果减弱，影响第一涂层的完整性；增强体颗粒太小时分散困难，导致第二涂层中增强体分布不均，抵抗冷压过程中活性材料对第一涂层破坏的效果减弱，影响第一涂层的完整性。
通过比较实施例1、36至39可知，随着第二涂层的厚度的增大，正极的常温电阻有增大的趋势；PTC响应温度保持不变；150℃和180℃下的电阻有增大的趋势。第二涂层的厚度增大，对第一涂层的保护程度增强，使第一涂层在冷压过程中受到的破坏减弱，第一涂层的完整性增强。当然，随着第二涂层的厚度的增大，电化学装置的能量密度会有所降低。如果第二涂层的厚度太小，则其保护效果减弱；如果第二涂层的厚度太大，则第二涂层的常温电阻也会升高，不利于锂离子电池的电性能的提升。
以上描述仅为本申请的较佳实施例以及对所运用技术原理的说明。本领域技术人员应当理解，本申请中所涉及的公开范围，并不限于上述技术特征的特定组合而成的技术方案，同时也应涵盖由上述技术特征或其等同特征进行任意组合而形成的其它技术方案。例如上述特征与本申请中公开的具有类似功能的技术特征进行互相替换而形成的技术方案。

Claims (12)

  1. 一种电化学装置，其包括电极，所述电极包括集流体、第一涂层、第二涂层和活性材料层，
    其中，所述第一涂层位于所述集流体和所述第二涂层之间，所述第二涂层位于所述第一涂层和所述活性材料层之间，所述第一涂层包括正温度系数材料和第一导电剂，所述第二涂层包括第二导电剂、粘结剂和增强体。
  2. 根据权利要求1所述的电化学装置，其中，所述增强体包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮、聚酰胺或纤维素粉中的至少一种。
  3. 根据权利要求1所述的电化学装置，其中，所述增强体满足以下条件中的至少一个：
    所述第二涂层中的所述增强体的质量含量为40％至98％；
    所述增强体的维氏硬度为600至2000；
    所述增强体的颗粒球形度范围在0.5至1；
    所述增强体的Dv50为0.05μm至2μm。
  4. 根据权利要求1所述的电化学装置，其中，所述增强体满足以下条件中的至少一个：
    所述第二涂层中的所述增强体的质量含量为60％至80％；
    所述增强体的维氏硬度为800至1500；
    所述增强体的颗粒球形度范围为0.7至1；
    所述增强体的Dv50为0.2μm至1μm。
  5. 根据权利要求1所述的电化学装置，其中，所述第二涂层的厚度为0.2μm至5μm，第二涂层覆盖度在60％以上。
  6. 根据权利要求1所述的电化学装置，其中，所述第二涂层中的所述第二导电剂、所述粘结剂和所述增强体的质量比为(1至20)∶(1至20)∶(60至98)。
  7. 根据权利要求1所述的电化学装置，其中，所述粘结剂包括聚乙烯醇、聚丙烯酸、聚乙二醇、聚环氧乙烯、羧甲基纤维素盐、聚丙烯酰胺、聚马来 酸酐、聚季胺盐、淀粉、壳聚糖、果胶、聚丙烯酸酯、聚氯醋、聚氯乙烯、天然橡胶乳液、氯丁乳液、丁腈乳液、丁苯乳液或苯丙乳液中的至少一种。
  8. 根据权利要求1所述的电化学装置，其中，所述正温度系数材料满足以下条件中的至少一个：
    所述正温度系数材料的熔点为115℃至180℃；
    所述正温度系数材料包括聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、聚四氟乙烯、聚对苯二甲酸丁二醇酯、聚酰亚胺、聚乙烯醇、聚甲基丙烯酸甲酯、聚偏二氟乙烯、聚丙烯腈、聚甲醛、乙烯-醋酸乙烯共聚物或聚对苯二甲酸乙二醇酯中的至少一种；
    所述第一涂层中的所述正温度系数材料的质量含量为60％至98％。
  9. 根据权利要求1所述的电化学装置，其中，所述第一涂层的厚度为0.5μm至12μm。
  10. 根据权利要求1所述的电化学装置，其中，所述第一导电剂和所述第二导电剂各自独立地包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。
  11. 根据权利要求1所述的电化学装置，其中，所述第一涂层中的所述第一导电剂的质量含量为2％至40％。
  12. 一种电子装置，包括根据权利要求1至11中任一项所述的电化学装置。
PCT/CN2021/084501 2021-03-31 2021-03-31 电化学装置和电子装置 WO2022205110A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202180004994.2A CN114270561B (zh) 2021-03-31 2021-03-31 电化学装置和电子装置
PCT/CN2021/084501 WO2022205110A1 (zh) 2021-03-31 2021-03-31 电化学装置和电子装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/084501 WO2022205110A1 (zh) 2021-03-31 2021-03-31 电化学装置和电子装置

Publications (1)

Publication Number Publication Date
WO2022205110A1 true WO2022205110A1 (zh) 2022-10-06

Family

ID=80833712

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/084501 WO2022205110A1 (zh) 2021-03-31 2021-03-31 电化学装置和电子装置

Country Status (2)

Country Link
CN (1) CN114270561B (zh)
WO (1) WO2022205110A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117133927B (zh) * 2023-10-25 2024-04-02 宁德时代新能源科技股份有限公司 复合正极集流体、正极极片、卷绕结构电芯及用电装置
CN117117205B (zh) * 2023-10-25 2024-04-02 宁德时代新能源科技股份有限公司 复合负极集流体、负极极片、卷绕结构电芯及二次电池

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101471435A (zh) * 2007-12-25 2009-07-01 比亚迪股份有限公司 锂离子二次电池正极及包括该正极的锂离子二次电池
US20180006289A1 (en) * 2016-07-01 2018-01-04 Lg Chem, Ltd. Positive electrode for lithium secondary battery and method for preparing the same
CN109755467A (zh) * 2017-11-08 2019-05-14 宁德时代新能源科技股份有限公司 一种电极极片、电化学装置及安全涂层
CN110783530A (zh) * 2018-07-27 2020-02-11 丰田自动车株式会社 固体电池用电极的制造方法
CN111200102A (zh) * 2018-11-16 2020-05-26 宁德时代新能源科技股份有限公司 一种正极极片及电化学装置
CN111785925A (zh) * 2020-08-11 2020-10-16 天津市捷威动力工业有限公司 极片及应用、含有该极片的低温升高安全性锂离子电池

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180076449A1 (en) * 2015-03-24 2018-03-15 Nec Corporation Negative electrode for lithium ion secondary battery and secondary battery
CN109755466B (zh) * 2017-11-08 2020-11-17 宁德时代新能源科技股份有限公司 一种正极极片、电化学装置及安全涂层
JP6962286B2 (ja) * 2018-07-27 2021-11-05 トヨタ自動車株式会社 固体電池用電極及び固体電池
JP7017127B2 (ja) * 2018-07-27 2022-02-08 トヨタ自動車株式会社 固体電池用電極の製造方法
JP7087784B2 (ja) * 2018-07-27 2022-06-21 トヨタ自動車株式会社 固体電池用電極及び固体電池
JP7147330B2 (ja) * 2018-07-27 2022-10-05 トヨタ自動車株式会社 固体電池用電極及び固体電池
JP6973319B2 (ja) * 2018-07-27 2021-11-24 トヨタ自動車株式会社 固体電池用電極及び固体電池
CN209045679U (zh) * 2018-11-05 2019-06-28 宁德新能源科技有限公司 电化学装置及包含其的电子装置
CN110357135B (zh) * 2019-06-19 2020-11-24 苏州盛曼特新材料有限公司 一种高纯锂电池隔膜用特种氧化铝的制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101471435A (zh) * 2007-12-25 2009-07-01 比亚迪股份有限公司 锂离子二次电池正极及包括该正极的锂离子二次电池
US20180006289A1 (en) * 2016-07-01 2018-01-04 Lg Chem, Ltd. Positive electrode for lithium secondary battery and method for preparing the same
CN109755467A (zh) * 2017-11-08 2019-05-14 宁德时代新能源科技股份有限公司 一种电极极片、电化学装置及安全涂层
CN110783530A (zh) * 2018-07-27 2020-02-11 丰田自动车株式会社 固体电池用电极的制造方法
CN111200102A (zh) * 2018-11-16 2020-05-26 宁德时代新能源科技股份有限公司 一种正极极片及电化学装置
CN111785925A (zh) * 2020-08-11 2020-10-16 天津市捷威动力工业有限公司 极片及应用、含有该极片的低温升高安全性锂离子电池

Also Published As

Publication number Publication date
CN114270561B (zh) 2024-08-27
CN114270561A (zh) 2022-04-01

Similar Documents

Publication Publication Date Title
WO2022204967A1 (zh) 电化学装置和电子装置
EP3588613A1 (en) Electrochemical device
JP5326036B2 (ja) リチウム二次電池
KR100659854B1 (ko) 리튬 이차 전지
JP5534718B2 (ja) 電極組立体、および二次電池
CN113707867B (zh) 电化学装置和电子装置
WO2022204968A1 (zh) 电化学装置和电子装置
US8574760B2 (en) Safety-enhanced electrochemical device including electrode containing binder and wax
JP2010192200A (ja) 非水電解質二次電池
KR20090103010A (ko) 전극조립체 및 이를 구비하는 리튬 이차 전지
CN106654125A (zh) 通过多巴胺复合粘结剂制备改性陶瓷隔膜的方法及其应用
WO2022262287A1 (zh) 电化学装置和电子装置
CA3040031C (en) Battery module for starting a power equipment
WO2022041194A1 (zh) 极片、电化学装置和电子装置
WO2022198577A1 (zh) 电化学装置和电子装置
WO2022198401A1 (zh) 电化学装置和电子装置
WO2022205110A1 (zh) 电化学装置和电子装置
US8178245B2 (en) Electrode assembly having porous separator that contains an antacid and secondary battery having the same
JP7469489B2 (ja) 電極片、電気化学装置及びそれを含む電子装置
KR100954591B1 (ko) 전극조립체 및 이를 구비하는 리튬 이차 전지
JP3778805B2 (ja) 二次電池
WO2023184233A1 (zh) 一种包含保护层的电化学装置及电子装置
WO2024060128A1 (zh) 电化学装置和电子装置
KR20090084203A (ko) 전극조립체 및 이를 구비하는 이차전지

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: 21933779

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21933779

Country of ref document: EP

Kind code of ref document: A1