WO2021195938A1 - Electrochemical device and battery pack - Google Patents

Electrochemical device and battery pack Download PDF

Info

Publication number
WO2021195938A1
WO2021195938A1 PCT/CN2020/082358 CN2020082358W WO2021195938A1 WO 2021195938 A1 WO2021195938 A1 WO 2021195938A1 CN 2020082358 W CN2020082358 W CN 2020082358W WO 2021195938 A1 WO2021195938 A1 WO 2021195938A1
Authority
WO
WIPO (PCT)
Prior art keywords
positive
electrochemical device
lithium
negative
active material
Prior art date
Application number
PCT/CN2020/082358
Other languages
French (fr)
Chinese (zh)
Inventor
韩翔龙
陶涛
杨超
Original Assignee
宁德新能源科技有限公司
东莞新能安科技有限公司
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, 东莞新能安科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to PCT/CN2020/082358 priority Critical patent/WO2021195938A1/en
Priority to CN202080001975.XA priority patent/CN112335089A/en
Publication of WO2021195938A1 publication Critical patent/WO2021195938A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This application relates to the field of energy storage technology, and in particular to an electrochemical device and a battery pack including the electrochemical device.
  • Lithium-ion batteries electrochemical devices
  • electrochemical devices have the advantages of large specific energy, high working voltage, low self-discharge rate, small size, light weight, etc., and have a wide range of applications in the field of consumer electronics.
  • people have higher and higher requirements for the performance (especially energy density and cycle performance) of lithium-ion batteries.
  • the voltage platforms of conventional electric two-wheeled vehicle battery packs are 36V, 48V, 60V, 72V, 84V or 96V, and the number of corresponding lithium-ion batteries forming the battery pack needs to be an integer, generally 10 to 30.
  • the voltage platform of traditional lithium-ion batteries is different.
  • the voltage platform of lithium-ion batteries whose positive active material is lithium iron phosphate is about 3.2V
  • the voltage platform of lithium-ion batteries whose positive active material is lithium cobalt oxide is about 3.85V. Meet the specific voltage output of the battery pack.
  • the output voltage required by the voltage platform of the commonly used electric two-wheeler battery pack is generally a multiple of 12V, requiring multiple lithium-ion batteries to be used in series, that is, the voltage platform of each lithium-ion battery is about 3.5V ⁇ 3.8V If the voltage platform of a single lithium-ion battery is too high, the overall design energy density is too high. A battery pack composed of multiple such lithium-ion batteries cannot reach the standard output voltage platform, which will affect the use of the battery pack and cause cost Increase; in the same way, if the voltage platform of a single lithium-ion battery is too low, the standard output voltage platform cannot be reached.
  • the application provides an electrochemical device, which includes a positive electrode, a negative electrode, a separator and an electrolyte.
  • the separator is disposed between the positive electrode and the negative electrode.
  • the positive electrode includes a positive electrode active material layer, and the positive electrode active material layer includes n types of positive electrode active materials.
  • the negative active material layer includes m types of negative active materials, wherein the voltage platform U 0 of the electrochemical device satisfies the following relationship:
  • U 0 voltage plateau in an electrochemical device
  • U n a positive voltage plateau
  • U a negative anode voltage plateau
  • U R & lt impedance partial pressure of the electrochemical device
  • x n the mass of the positive electrode active material of n In the proportion of the total mass of all n positive active materials
  • U positive n represents the voltage plateau of the n positive active material
  • y m represents the mass of the m negative active material in the total mass of all m negative active materials.
  • the proportion of mass, U minus m represents the voltage plateau of the m- th negative electrode active material, I 0 represents the discharge current of the electrochemical device, R represents the impedance of the electrochemical device, n is a positive integer and greater than or equal to 2, m It is a positive integer and greater than or equal to 1.
  • the value of I 0 is 10A.
  • the value of R is 1 milliohm to 30 milliohms.
  • R includes the positive electrode impedance, the negative electrode impedance, the electrolyte impedance, and the ohmic internal resistance of the electrochemical device.
  • the positive active material includes at least one of lithium iron phosphate or lithium manganate.
  • the positive active material further includes at least one of lithium nickel cobalt manganate or lithium nickel cobalt aluminate.
  • the negative active material includes artificial graphite, natural graphite, soft carbon, hard carbon, mesocarbon microspheres, silicon, silicon alloy, silicon-carbon composite, silicon-oxygen compound, lithium titanate, or titanic acid At least one of niobium.
  • the electrolyte includes a solvent and a lithium salt
  • the solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, and ethylene carbonate.
  • the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, or lithium trifluoromethanesulfonate.
  • the present application also provides a battery pack including the above electrochemical device.
  • the battery pack satisfies the following relationship:
  • U total represents the external output voltage platform of the battery pack, the unit is V, i represents the number of electrochemical devices; and the value of U total is selected from one of 36, 48, 60, 72, 84 or 96, and U There is always a deviation of ⁇ 0.5.
  • the electrochemical device provided in this application comprehensively considers the positive voltage platform, negative voltage platform, impedance partial pressure and other factors of the electrochemical device, so that the voltage platform U 0 of a single electrochemical device satisfies: 3.55V ⁇ U 0 ⁇ 3.76V, Therefore, when the total voltage platform of the battery pack applying the electrochemical device is 36V, 48V, 60V, 72V, 84V or 96V, the number of electrochemical devices is an integer.
  • a battery pack composed of multiple electrochemical devices of the present application can reach a standard output voltage platform, will not affect the use of the battery pack, and will not cause an increase in cost, so that the multiple electrochemical devices of the present application are composed The battery pack has a lower cost.
  • FIG. 1 is a discharge curve diagram of a lithium ion battery (electrochemical device) according to Example 3 of the application.
  • the application provides an electrochemical device.
  • the electrochemical device includes a positive electrode, a negative electrode, a separator and an electrolyte, and the separator is disposed between the positive electrode and the negative electrode.
  • the positive electrode includes a positive electrode active material layer, and the positive electrode active material layer includes n kinds of positive electrode active materials.
  • the negative electrode includes a negative electrode active material layer, and the negative electrode active material layer includes m types of negative electrode active materials. Among them, the voltage platform U 0 of the electrochemical device satisfies the following relationship:
  • U 0 denotes the voltage plateau in an electrochemical device
  • U represents the impedance R & lt partial pressure of the electrochemical device
  • x n represents a mass of the positive electrode active material of n In the proportion of the total mass of all n positive active materials
  • U positive n represents the voltage plateau of the n positive active material
  • y m represents the mass of the m negative active material in the total mass of all m negative active materials.
  • the proportion of mass, U minus m represents the voltage plateau of the m- th negative electrode active material, I 0 represents the discharge current of the electrochemical device, R represents the impedance of the electrochemical device, n is a positive integer and greater than or equal to 2, m It is a positive integer and greater than or equal to 1.
  • the voltage change of the electrochemical device is not a slope drop.
  • the voltage platform for electrochemical device discharge refers to the center voltage of the discharge curve. Before and after the center voltage, the voltage changes very slowly during discharge, for example, as shown in Figure 1. The voltage plateau shown is 3.659V. The same is true for the voltage platform of a battery pack composed of electrochemical devices.
  • the electrochemical device provided in this application comprehensively considers the positive voltage platform, negative voltage platform, impedance partial pressure and other factors of the electrochemical device, so that the voltage platform U 0 of a single electrochemical device satisfies: 3.55V ⁇ U 0 ⁇ 3.76V, Therefore, when the total voltage platform of the battery pack applying the electrochemical device is 36V, 48V, 60V, 72V, 84V or 96V, the number of electrochemical devices is an integer.
  • the voltage level of the positive electrode has a direct relationship with the type of positive active material and the proportion of the mass of each positive active material in the total mass of all positive active materials. They will greatly affect the output of the electrochemical device. Voltage platform.
  • the voltage plateau of the negative electrode is related to the type of negative electrode active material and the ratio of the mass of each negative electrode active material to the total mass of all negative electrode active materials.
  • the impedance partial pressure is related to the positive electrode impedance, the negative electrode impedance, the ohmic internal resistance, and the electrolyte impedance.
  • the factors affecting the impedance of the positive electrode and the negative electrode include: the composition and ratio of the positive active material layer, the composition and ratio of the negative electrode active material layer, the thickness of the positive electrode active material layer, the thickness of the negative electrode active material layer, the thickness of the positive electrode Compaction density, compaction density of negative pole piece, etc.
  • the lower the content of the conductive agent in the positive electrode active material layer and the negative electrode active material layer the greater the impedance of the positive electrode and the negative electrode
  • the greater the compaction density of the pole piece and the negative pole piece the greater the impedance of the positive electrode and the negative electrode.
  • the ohmic internal resistance including but not limited to the type and thickness of the current collector, the thickness of the tab, the type, thickness, and air permeability of the isolation membrane.
  • the value of I 0 is 10A.
  • I 0 10A
  • the current of the electrochemical device is close to the actual use state, the true use state of the electrochemical device can be obtained, and the impedance partial pressure of the electrochemical device in actual use can be accurately obtained, so that the electrochemical device is in actual use
  • the output voltage platform is 3.55V to 3.76V
  • the output voltage platform of the electrochemical device will not be in the range of 3.55V to 3.76V due to the inaccurate assessment of the impedance partial pressure.
  • the value of R is 1 milliohm to 30 milliohms.
  • the electrochemical device can obtain good electrochemical performance (such as cycle performance, fast charging performance), and on the other hand, it has less influence on the output voltage platform of the electrochemical device, so that Electrochemical devices have good overall performance.
  • R includes the positive electrode impedance, the negative electrode impedance, the electrolyte impedance, and the ohmic internal resistance of the electrochemical device. Because the output voltage platform range of the electrochemical device is small, if R does not consider the impact of these impedances on the output voltage platform, even if the voltage platform of the positive and negative electrodes meets the design of the output voltage platform, the small impedance partial pressure will cause the electrochemical device The output voltage platform is difficult to be in the range of 3.55V to 3.76V, which is caused by the small output voltage platform window of 3.55V to 3.76V.
  • the positive active material includes at least one of lithium iron phosphate or lithium manganate.
  • Lithium iron phosphate and lithium manganate can be coated and doped, such as carbon-coated lithium iron phosphate, where, due to the lower cost of lithium iron phosphate or lithium manganate, the positive electrode active material contains lithium iron phosphate or manganese acid At least one of lithium can significantly reduce the cost of electrochemical devices and battery packs, thereby having broad market competitiveness.
  • the positive electrode active material further includes at least one of lithium nickel cobalt manganate or lithium nickel cobalt aluminate.
  • lithium nickel cobalt manganate or lithium nickel cobalt aluminate because the energy density of lithium iron phosphate or lithium manganate is lower, and the energy density of lithium nickel cobalt manganate or lithium nickel cobalt aluminate is higher, it is better to choose lithium nickel cobalt manganate or lithium nickel cobalt aluminate. Further improve the energy density of electrochemical devices and battery packs.
  • lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminate is: Li x Co y Ni z M 1-yz O b X ba ; where M is boron, magnesium, aluminum, silicon, phosphorus, sulfur, titanium, One or more elements of chromium, manganese, iron, copper, zinc, gallium, germanium, yttrium, zirconium, molybdenum, silver, barium, tungsten, indium, tin, lead, and antimony, x, y, z, a , B satisfies: 0.8 ⁇ x ⁇ 1.2, 0 ⁇ y ⁇ 0.5, 0.5 ⁇ z ⁇ 1.0, 1-yz>0, 1.8 ⁇ b ⁇ 2.2, and 0 ⁇ a ⁇ 1.0.
  • the positive active material layer further includes a first binder and a conductive agent.
  • the positive active material is mixed with the first binder and the conductive agent.
  • the conductive agent and the first binder are commonly used in the industry and can be used for the positive electrode.
  • the conductive agent may include at least one of conductive carbon black, graphene, carbon nanotube, carbon fiber, or Ketjen black.
  • the first binder can be selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, poly At least one of ethylene pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, or polyhexafluoropropylene.
  • the positive electrode further includes a positive electrode current collector, and the positive electrode active material layer is supported on the positive electrode current collector.
  • the negative active material includes artificial graphite, natural graphite, soft carbon, hard carbon, mesocarbon microspheres, silicon, silicon alloy, silicon-carbon composite, silicon-oxygen compound, lithium titanate, or titanic acid At least one of niobium.
  • the negative active material layer further includes a second binder, and the second binder is mixed with the negative active material.
  • the negative electrode further includes a negative electrode current collector, and the negative electrode active material layer is supported on the negative electrode current collector.
  • the electrochemical device of the present application does not specifically limit the material, structure, etc. of the isolation membrane.
  • the isolation film includes, but is not limited to, at least one selected from polyethylene, polypropylene, polyethylene terephthalate, polyimide, and aramid.
  • polyethylene includes at least one component selected from high-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene.
  • 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 surface of the isolation membrane may also include a porous layer, the porous layer is provided on at least one surface of the isolation membrane, the porous layer includes one or two of 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 ), cerium oxide (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, calcium hydroxide And a combination of one or more of barium sulfate.
  • alumina Al 2 O 3
  • silicon oxide SiO 2
  • magnesium oxide MgO
  • titanium oxide TiO 2
  • the binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, polyvinyl pyrrole A combination of one or more of alkanone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, and polyhexafluoropropylene.
  • the electrolyte includes a solvent and a lithium salt
  • the solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, and ethylene carbonate.
  • the electrolyte further includes other non-aqueous solvents other than the above, and 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 cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.
  • Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl ethylene carbonate (VEC), or a combination thereof.
  • Examples of fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethyl, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, or a combination thereof.
  • carboxylic acid ester compounds are methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, decanolide, valerolactone, methyl valerate Lonicolactone, caprolactone, methyl formate, or a combination thereof.
  • ether compounds are dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxy Methyl ethane, 2-methyltetrahydrofuran, tetrahydrofuran, or a combination thereof.
  • organic solvents examples include dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, methyl Amide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, phosphate ester, or a combination thereof.
  • the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, or lithium trifluoromethanesulfonate.
  • the present application also provides a battery pack including the above electrochemical device.
  • the battery pack satisfies the following relationship:
  • V total represents the external output voltage platform of the battery pack
  • the unit is V
  • i represents the number of electrochemical devices
  • the value of U total is selected from one of 36, 48, 60, 72, 84 or 96, and U There is always a deviation of ⁇ 0.5.
  • a battery pack composed of multiple electrochemical devices of the present application can reach a standard output voltage platform, without affecting the use of the battery pack, and will not cause an increase in cost, so that a battery composed of multiple electrochemical devices of the present application is applied
  • the group has a lower cost.
  • lithium ion batteries involved in the following specific embodiments all refer to electrochemical devices.
  • the positive electrode current collector Using aluminum foil as the positive electrode current collector (the thickness of the aluminum foil is 16 ⁇ m), the positive electrode slurry is coated on both sides of the positive electrode current collector (coating weight 0.25kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.5g/cm 3 ), the positive electrode is obtained after cutting.
  • Preparation of negative electrode Dissolve artificial graphite (U negative 1 is 0.1V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material. Copper foil is used as the negative electrode current collector (the thickness of the copper foil is 8 ⁇ m), and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.089kg/m 2 ), after drying and cold pressing (compaction of the negative electrode) The density is 1.6 g/cm 3 ), and the negative electrode is obtained after cutting.
  • lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 10:90 to form an electrolyte (lithium salt concentration 1 mol/L).
  • the preparation of the isolation membrane a single-layer polypropylene (thickness of 14 ⁇ m) is selected as the membrane, and the air permeability is 76s/100cm 3 .
  • Lithium-ion battery preparation stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80°C, and then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 2.5 m ⁇ .
  • the voltage platform of the battery pack is 47.84V, the capacity is 20Ah, the number of lithium-ion batteries is 13, and the voltage platform corresponding to the lithium-ion battery is 3.68V, and the discharge current is 10A.
  • the preparation of the negative electrode the artificial graphite (U minus 1 is 0.1V), Si (U minus 2 is 0.6V), styrene butadiene rubber and sodium carboxymethyl cellulose are mixed in a weight ratio of 92.8:4.9:1.0:1.3 ( Correspondingly, the mass proportion y 1 of artificial graphite is 0.95, and the mass proportion y 2 of Si is 0.05), and the preparation process is the same as in Example 1.
  • the isolation membrane Preparation of the isolation membrane: a single layer of polyethylene (thickness of 9 ⁇ m) is selected as the isolation membrane, and a slurry of alumina and polyvinylidene fluoride is coated on one side (the ratio is 7:3), and the coated isolation membrane is obtained
  • the air permeability is 85s/100cm 3 .
  • Lithium-ion battery preparation stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80°C, and then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 3.0 m ⁇ .
  • the voltage platform of the battery pack is 60.35V (within the range of 60 ⁇ 0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 17, and the voltage platform corresponding to the lithium-ion battery requires 3.55V, and the discharge current is 10A.
  • the positive electrode current collector Using aluminum foil as the positive electrode current collector (the thickness of the aluminum foil is 10 ⁇ m), the positive electrode slurry is coated on the positive electrode current collector (0.22kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.6g/cm 3 ). The positive electrode is obtained after cutting.
  • Copper foil is used as the negative electrode current collector, and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.080kg/m 2 ), dried and cold pressed (the compaction density of the negative electrode is 1.62g/cm 3 ) , The negative electrode is obtained after the cutting process.
  • lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 8:92 to form an electrolyte (lithium salt concentration 1 mol/L).
  • the preparation of the isolation membrane a polypropylene/polyethylene/polypropylene three-layer composite diaphragm (thickness of 16 ⁇ m) is selected, one side is coated with ceramics, and the air permeability is 200s/100cm 3 .
  • the voltage platform of the battery pack is 47.567V (within the range of 48 ⁇ 0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 13, and the platform voltage corresponding to the lithium-ion battery is 3.659V, and the discharge current is 10A.
  • the tube and polyvinylidene fluoride are dissolved in a weight ratio of 19.2:76.8:1:0.6:2.4 (corresponding to the weight ratio of nickel cobalt lithium manganate x 1 is 0.2, and the weight ratio of lithium manganate x 2 is 0.8)
  • N-methylpyrrolidone solution a positive electrode slurry is formed.
  • the preparation process is as in Example 2.
  • the preparation of the isolation membrane a polypropylene/polyethylene/polypropylene three-layer composite diaphragm (thickness of 16 ⁇ m) is selected, one side is coated with ceramics, and the air permeability is 200s/100cm 3 .
  • the voltage platform of the battery pack is 48.23V (within the range of 48 ⁇ 0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 13, and the platform voltage corresponding to the lithium-ion battery is 3.71V, and the discharge current is 10A.
  • the tube and polyvinylidene fluoride are dissolved in a weight ratio of 19.2:76.8:1:0.6:2.4 (corresponding to the weight ratio of nickel cobalt lithium manganate x 1 is 0.2, and the weight ratio of lithium manganate x 2 is 0.8)
  • N-methylpyrrolidone solution a positive electrode slurry is formed.
  • the preparation process is as in Example 1.
  • Preparation of negative electrode Dissolve artificial graphite (U negative 1 is 0.08V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material.
  • the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.085kg/m 2 ), after drying and cold pressing (the negative electrode is compacted) The density is 1.61 g/cm 3 ), and the negative electrode is obtained after cutting.
  • lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 12.5:87.5 to form an electrolyte (lithium salt concentration 1 mol/L).
  • the voltage platform of the battery pack is 60.16V (within the range of 60 ⁇ 0.5V), the capacity is 30Ah, the number of lithium-ion batteries is 16, and the platform voltage corresponding to the lithium-ion battery is 3.76V, and the discharge current is 10A.
  • Lithium iron phosphate (U positive 1 is 3.3V), conductive carbon black, carbon nanotubes, polyvinylidene fluoride in a weight ratio of 96:0.8:0.8:2.4 (corresponding to the mass ratio of lithium iron phosphate , X 1 is 1) Dissolve in N-methylpyrrolidone solution to form positive electrode slurry.
  • the positive electrode current collector (the thickness of the aluminum foil is 16 ⁇ m)
  • the positive electrode slurry is coated on both sides of the positive electrode current collector (coating weight 0.25kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.5g/cm 3 ), the positive electrode is obtained after cutting.
  • Preparation of negative electrode Dissolve artificial graphite (U negative 1 is 0.1V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material. Copper foil is used as the negative electrode current collector (the thickness of the copper foil is 8 ⁇ m), and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.089kg/m 2 ), after drying and cold pressing (compaction of the negative electrode) The density is 1.6 g/cm 3 ), and the negative electrode is obtained after cutting.
  • lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 10:90 to form an electrolyte (lithium salt concentration 1 mol/L).
  • the preparation of the isolation membrane a single-layer polypropylene (thickness of 14 ⁇ m) is selected as the membrane, and the air permeability is 76s/100cm 3 .
  • Lithium-ion battery preparation stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80°C, then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 5 m ⁇ .
  • the voltage platform of the lithium-ion battery is 3.15V. When 16 lithium-ion batteries form a battery pack, the output voltage platform is 50.4V, and when 15 lithium-ion batteries form a battery pack, the output voltage platform is 47.25V. Comparing Comparative Example 1 with Example 1, Comparative Example 1 cannot reach the standard output voltage platform of 48 ⁇ 0.5V.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)

Abstract

An electrochemical device and a battery pack comprising multiple electrochemical devices. The electrochemical device comprises a positive electrode, a negative electrode, a separator film, and an electrolyte. The voltage U 0 of the electrochemical device satisfies the following relational expressions: U 0=U positive-U negative-U r; U positive=x 1U positive 1+x 2U positive 2+…+x nU positive n; U negative=y 1U negative 1+y 2U negative 2+…+y mU negative m; U r=I 0*R; and 3.55 V≤U 0≤3.76 V, wherein U 0, U r, U positive, and U negative respectively represent the voltage of the electrochemical device, an impedance partial voltage, a voltage platform of the positive electrode, and a voltage platform of the negative electrode; x n represents the proportion of the mass of an n-th positive electrode active material in the total mass of all n positive electrode active materials; U positive n and U negative m respectively represent the voltage platforms of the n-th positive electrode and m-th negative electrode active materials; y m represents the proportion of the mass of the m-th negative electrode active material in the total mass of all m negative electrode active materials; I 0 and R respectively represent the discharge current and impedance of the electrochemical device; n is greater than or equal to 2 and is a positive integer, and m is greater than or equal to 1 and is a positive integer.

Description

电化学装置及电池组Electrochemical device and battery pack 技术领域Technical field
本申请涉及储能技术领域，尤其涉及一种电化学装置及包括电化学装置的电池组。This application relates to the field of energy storage technology, and in particular to an electrochemical device and a battery pack including the electrochemical device.
背景技术Background technique
锂离子电池(电化学装置)具有比能量大、工作电压高、自放电率低、体积小、重量轻等优势，在消费电子领域具有广泛的应用。然而随着电动汽车和可移动电子设备的高速发展，人们对锂离子电池的性能(尤其是能量密度以及循环性能)的要求越来越高。Lithium-ion batteries (electrochemical devices) have the advantages of large specific energy, high working voltage, low self-discharge rate, small size, light weight, etc., and have a wide range of applications in the field of consumer electronics. However, with the rapid development of electric vehicles and portable electronic devices, people have higher and higher requirements for the performance (especially energy density and cycle performance) of lithium-ion batteries.
随着全球各国禁售燃油车时间表的陆续公布，新能源产业再次迎来一波发展热潮。可以预见的是锂离子电池未来在电动车行业将会被广泛应用。With the successive announcement of the timetable for the ban on the sale of fuel vehicles in countries around the world, the new energy industry has once again ushered in a wave of development. It is foreseeable that lithium-ion batteries will be widely used in the electric vehicle industry in the future.
目前常规电动两轮车电池组的电压平台有36V、48V、60V、72V、84V或96V，而组成电池组的对应锂离子电池的数量需要整数个，一般为10个～30个。这就要求锂离子电池的电压平台在3.5V～3.8V之间这个比较小的电压平台窗口内。传统锂离子电池的电压平台高低不一，例如正极活性物质为磷酸铁锂的锂离子电池的电压平台为3.2V左右，正极活性物质为钴酸锂的锂离子电池的电压平台3.85V左右，无法满足电池组的特定电压的输出。At present, the voltage platforms of conventional electric two-wheeled vehicle battery packs are 36V, 48V, 60V, 72V, 84V or 96V, and the number of corresponding lithium-ion batteries forming the battery pack needs to be an integer, generally 10 to 30. This requires the voltage platform of the lithium-ion battery to be within the relatively small voltage platform window between 3.5V and 3.8V. The voltage platform of traditional lithium-ion batteries is different. For example, the voltage platform of lithium-ion batteries whose positive active material is lithium iron phosphate is about 3.2V, and the voltage platform of lithium-ion batteries whose positive active material is lithium cobalt oxide is about 3.85V. Meet the specific voltage output of the battery pack.
常用的电动两轮车电池组的电压平台所需要的输出电压一般为12V的倍数，需要多个锂离子电池串联在一起使用，即需要每个锂离子电池的电压平台为约3.5V～3.8V，如果单个锂离子电池的 电压平台过高则总体设计能量密度过高，由多个这样的锂离子电池组成的电池组无法达到标准输出电压平台，影响电池组的使用，同时还会导致成本的升高；同理，如果单个锂离子电池的电压平台过低同样无法达到标准输出电压平台。The output voltage required by the voltage platform of the commonly used electric two-wheeler battery pack is generally a multiple of 12V, requiring multiple lithium-ion batteries to be used in series, that is, the voltage platform of each lithium-ion battery is about 3.5V～3.8V If the voltage platform of a single lithium-ion battery is too high, the overall design energy density is too high. A battery pack composed of multiple such lithium-ion batteries cannot reach the standard output voltage platform, which will affect the use of the battery pack and cause cost Increase; in the same way, if the voltage platform of a single lithium-ion battery is too low, the standard output voltage platform cannot be reached.
发明内容Summary of the invention
为解决现有技术以上的不足，有必要提供一种输出电压平台为3.55V至3.76V且成本低的电化学装置。In order to solve the above shortcomings of the prior art, it is necessary to provide an electrochemical device with an output voltage platform of 3.55V to 3.76V and a low cost.
另，还有必要提供一种具有整数个如上所述的电化学装置的电池组。In addition, it is also necessary to provide a battery pack having an integer number of electrochemical devices as described above.
本申请提供一种电化学装置，其包括正极、负极、隔离膜及电解液，隔离膜设置于正极与负极之间，正极包括正极活性物质层，正极活性物质层包括n种正极活性物质，负极包括负极活性物质层，负极活性物质层包括m种负极活性物质，其中，电化学装置的电压平台U 0满足如下关系式： The application provides an electrochemical device, which includes a positive electrode, a negative electrode, a separator and an electrolyte. The separator is disposed between the positive electrode and the negative electrode. The positive electrode includes a positive electrode active material layer, and the positive electrode active material layer includes n types of positive electrode active materials. Including the negative active material layer, the negative active material layer includes m types of negative active materials, wherein the voltage platform U 0 of the electrochemical device satisfies the following relationship:
U 0＝U 正-U 负-U r  (式1)； U 0 ＝U positive- U negative- U r (Equation 1);
U 正＝x 1U 正1+x 2U 正2+…..+x nU 正n  (式2)； U positive = x 1 U positive 1 + x 2 U positive 2 +…..+x n U positive n (Equation 2);
U 负＝y 1U 负1+y 2U 负2+…..+y mU 负m  (式3)； U minus = y 1 U minus 1 +y 2 U minus 2 +...+y m U minus m (Equation 3);
U r＝I 0*R  (式4)； U r =I 0 *R (Equation 4);
3.55V≤U 0≤3.76V  (式5)； 3.55V≤U 0 ≤3.76V (Equation 5);
其中，U 0表示电化学装置的电压平台，U 正表示正极的电压平台，U 负表示负极的电压平台，U r表示电化学装置的阻抗分压，x n表示第n种正极活性物质的质量在所有n种正极活性物质的总质量中所占的比例，U 正n表示第n种正极活性物质的电压平台，y m表示第m种负极活性物质的质量在所有m种负极活性物质的总质量中所占的比例，U 负m表示第m种负极活性物质的电压平台，I 0表示电化学装 置的放电电流，R表示电化学装置的阻抗，n为正整数且大于或等于2，m为正整数且大于或等于1。 Wherein, U represents 0 voltage plateau in an electrochemical device, U n represents a positive voltage plateau, U represents a negative anode voltage plateau, U represents R & lt impedance partial pressure of the electrochemical device, x n represents the mass of the positive electrode active material of n In the proportion of the total mass of all n positive active materials, U positive n represents the voltage plateau of the n positive active material, and y m represents the mass of the m negative active material in the total mass of all m negative active materials. The proportion of mass, U minus m represents the voltage plateau of the m- th negative electrode active material, I 0 represents the discharge current of the electrochemical device, R represents the impedance of the electrochemical device, n is a positive integer and greater than or equal to 2, m It is a positive integer and greater than or equal to 1.
在本申请一些实施例中，I 0的值为10A。 In some embodiments of the present application, the value of I 0 is 10A.
在本申请一些实施例中，R的值为1毫欧～30毫欧。In some embodiments of the present application, the value of R is 1 milliohm to 30 milliohms.
在本申请一些实施例中，R包括电化学装置的正极阻抗、负极阻抗、电解液阻抗和欧姆内阻。In some embodiments of the present application, R includes the positive electrode impedance, the negative electrode impedance, the electrolyte impedance, and the ohmic internal resistance of the electrochemical device.
在本申请一些实施例中，正极活性物质包含磷酸铁锂或锰酸锂中的至少一种。In some embodiments of the present application, the positive active material includes at least one of lithium iron phosphate or lithium manganate.
在本申请一些实施例中，正极活性物质还包含镍钴锰酸锂或镍钴铝酸锂中的至少一种。In some embodiments of the present application, the positive active material further includes at least one of lithium nickel cobalt manganate or lithium nickel cobalt aluminate.
在本申请一些实施例中，负极活性物质包含人造石墨、天然石墨、软碳、硬碳、中间相碳微球、硅、硅合金、硅碳复合物、硅氧化合物、钛酸锂或钛酸铌中的至少一种。In some embodiments of the present application, the negative active material includes artificial graphite, natural graphite, soft carbon, hard carbon, mesocarbon microspheres, silicon, silicon alloy, silicon-carbon composite, silicon-oxygen compound, lithium titanate, or titanic acid At least one of niobium.
在本申请一些实施例中，电解液包括溶剂和锂盐，溶剂包含碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸乙丙酯、碳酸乙丁酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、碳酸亚乙烯酯或亚硫酸丙烯酯中的至少一种。In some embodiments of the present application, the electrolyte includes a solvent and a lithium salt, and the solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, and ethylene carbonate. At least one of ester, propylene carbonate, butylene carbonate, γ-butyrolactone, vinylene carbonate, or propylene sulfite.
在本申请一些实施例中，锂盐包含六氟磷酸锂、四氟硼酸锂、六氟砷酸锂、高氯酸锂或三氟甲基磺酸锂中的至少一种。In some embodiments of the present application, the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, or lithium trifluoromethanesulfonate.
本申请还提供一种包括如上的电化学装置的电池组。电池组满足如下关系式：The present application also provides a battery pack including the above electrochemical device. The battery pack satisfies the following relationship:
U 总＝U 0*i  (式6)； U total = U 0 *i (Equation 6);
其中，U 总表示电池组的对外输出电压平台，单位为V，i表示电化学装置的个数；及U 总的值选自36、48、60、72、84或96中的一个，且U 总具有±0.5的偏差。 Among them, U total represents the external output voltage platform of the battery pack, the unit is V, i represents the number of electrochemical devices; and the value of U total is selected from one of 36, 48, 60, 72, 84 or 96, and U There is always a deviation of ±0.5.
本申请提供的电化学装置综合考虑电化学装置的正极电压平 台、负极电压平台、阻抗分压等多种因素，使得单个电化学装置的电压平台U 0满足：3.55V≤U 0≤3.76V，从而使得应用电化学装置的电池组的总电压平台为36V、48V、60V、72V、84V或96V时，电化学装置的个数为整数。另外，应用本申请的多个电化学装置组成的电池组能够达到标准输出电压平台，不会影响电池组的使用，也不会导致成本的升高，从而应用本申请的多个电化学装置组成的电池组具有较低的成本。 The electrochemical device provided in this application comprehensively considers the positive voltage platform, negative voltage platform, impedance partial pressure and other factors of the electrochemical device, so that the voltage platform U 0 of a single electrochemical device satisfies: 3.55V≤U 0 ≤3.76V, Therefore, when the total voltage platform of the battery pack applying the electrochemical device is 36V, 48V, 60V, 72V, 84V or 96V, the number of electrochemical devices is an integer. In addition, a battery pack composed of multiple electrochemical devices of the present application can reach a standard output voltage platform, will not affect the use of the battery pack, and will not cause an increase in cost, so that the multiple electrochemical devices of the present application are composed The battery pack has a lower cost.
附图说明Description of the drawings
图1为本申请实施例3的锂离子电池(电化学装置)的放电曲线图。FIG. 1 is a discharge curve diagram of a lithium ion battery (electrochemical device) according to Example 3 of the application.
具体实施方式Detailed ways
下面将结合本申请实施例对本申请实施例中的技术方案进行清楚、详细地描述，显然，所描述的实施例仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。The technical solutions in the embodiments of the present application will be described clearly and in detail below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请。本申请所使用的术语“及/或”包括一个或多个相关的所列项目的任意的和所有的组合。Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field of this application. The terminology used in the description of this application is only for the purpose of describing specific embodiments, and is not intended to limit the application. The term "and/or" used in this application includes any and all combinations of one or more related listed items.
本申请提供一种电化学装置，电化学装置包括正极、负极、隔离膜及电解液，隔离膜设置于正极与负极之间。正极包括正极活性物质层，正极活性物质层包括n种正极活性物质。负极包括负极活 性物质层，负极活性物质层包括m种负极活性物质。其中，电化学装置的电压平台U 0满足如下关系式： The application provides an electrochemical device. The electrochemical device includes a positive electrode, a negative electrode, a separator and an electrolyte, and the separator is disposed between the positive electrode and the negative electrode. The positive electrode includes a positive electrode active material layer, and the positive electrode active material layer includes n kinds of positive electrode active materials. The negative electrode includes a negative electrode active material layer, and the negative electrode active material layer includes m types of negative electrode active materials. Among them, the voltage platform U 0 of the electrochemical device satisfies the following relationship:
U 0＝U 正-U 负-U r  (式1)； U 0 ＝U positive- U negative- U r (Equation 1);
U 正＝x 1U 正1+x 2U 正2+…..+x nU 正n  (式2)； U positive = x 1 U positive 1 + x 2 U positive 2 +…..+x n U positive n (Equation 2);
U 负＝y 1U 负1+y 2U 负2+…..+y mU 负m  (式3)； U minus = y 1 U minus 1 +y 2 U minus 2 +...+y m U minus m (Equation 3);
U r＝I 0*R  (式4)； U r =I 0 *R (Equation 4);
3.55V≤U 0≤3.76V  (式5)； 3.55V≤U 0 ≤3.76V (Equation 5);
其中，U 0表示电化学装置的电压平台，U 正表示正极的电压平台，U 负表示负极的电压平台，U r表示电化学装置的阻抗分压，x n表示第n种正极活性物质的质量在所有n种正极活性物质的总质量中所占的比例，U 正n表示第n种正极活性物质的电压平台，y m表示第m种负极活性物质的质量在所有m种负极活性物质的总质量中所占的比例，U 负m表示第m种负极活性物质的电压平台，I 0表示电化学装置的放电电流，R表示电化学装置的阻抗，n为正整数且大于或等于2，m为正整数且大于或等于1。 Wherein, U 0 denotes the voltage plateau in an electrochemical device, U We display the positive voltage plateau, U Biaoshi negative negative voltage plateau, U represents the impedance R & lt partial pressure of the electrochemical device, x n represents a mass of the positive electrode active material of n In the proportion of the total mass of all n positive active materials, U positive n represents the voltage plateau of the n positive active material, and y m represents the mass of the m negative active material in the total mass of all m negative active materials. The proportion of mass, U minus m represents the voltage plateau of the m- th negative electrode active material, I 0 represents the discharge current of the electrochemical device, R represents the impedance of the electrochemical device, n is a positive integer and greater than or equal to 2, m It is a positive integer and greater than or equal to 1.
电化学装置在放电的时候，电化学装置的电压变化不是一个斜率下降。一般的，如图1，电化学装置刚开始放电的时候，电压下降比较快，随着放电的进行，电化学装置的电压几乎不变化，或者说变化很小，这一段占整个放电时间的绝大部分，也就是电化学装置放电的电压平台，需要说明的是，本申请电压平台的值是指放电曲线的中心电压，在此中心电压的前后，放电时电压变化很慢，例如，图1所示的电压平台为3.659V。由电化学装置组成的电池组的电压平台同样如此。When the electrochemical device is discharging, the voltage change of the electrochemical device is not a slope drop. Generally, as shown in Figure 1, when the electrochemical device first discharges, the voltage drops relatively quickly. As the discharge progresses, the voltage of the electrochemical device hardly changes, or the change is very small. This period accounts for the absolute total discharge time. Most of it is the voltage platform for electrochemical device discharge. It should be noted that the value of the voltage platform in this application refers to the center voltage of the discharge curve. Before and after the center voltage, the voltage changes very slowly during discharge, for example, as shown in Figure 1. The voltage plateau shown is 3.659V. The same is true for the voltage platform of a battery pack composed of electrochemical devices.
本申请提供的电化学装置综合考虑电化学装置的正极电压平台、负极电压平台、阻抗分压等多种因素，使得单个电化学装置的电压平台U 0满足：3.55V≤U 0≤3.76V，从而使得应用电化学装置的电 池组的总电压平台为36V、48V、60V、72V、84V或96V时，电化学装置的个数为整数个。 The electrochemical device provided in this application comprehensively considers the positive voltage platform, negative voltage platform, impedance partial pressure and other factors of the electrochemical device, so that the voltage platform U 0 of a single electrochemical device satisfies: 3.55V≤U 0 ≤3.76V, Therefore, when the total voltage platform of the battery pack applying the electrochemical device is 36V, 48V, 60V, 72V, 84V or 96V, the number of electrochemical devices is an integer.
具体地，正极的电压平台与正极活性物质的种类、各正极活性物质的质量在所有正极活性物质的总质量中所占的比例有直接的关系，它们会很大程度上影响电化学装置的输出电压平台。Specifically, the voltage level of the positive electrode has a direct relationship with the type of positive active material and the proportion of the mass of each positive active material in the total mass of all positive active materials. They will greatly affect the output of the electrochemical device. Voltage platform.
具体地，负极的电压平台与负极活性物质的种类、各负极活性物质的质量在所有负极活性物质的总质量中所占的比例有关。Specifically, the voltage plateau of the negative electrode is related to the type of negative electrode active material and the ratio of the mass of each negative electrode active material to the total mass of all negative electrode active materials.
具体地，阻抗分压与正极阻抗、负极阻抗、欧姆内阻及电解液阻抗等有关。Specifically, the impedance partial pressure is related to the positive electrode impedance, the negative electrode impedance, the ohmic internal resistance, and the electrolyte impedance.
具体地，正、负极阻抗的影响因素有：正活性物质层的组成和配比、负极活性物质层的组成和配比，正极活性物质层的厚度，负极活性物质层的厚度，正极极片的压实密度，负极极片的压实密度等。例如，正极活性物质层和负极活性物质层中导电剂的含量越低，正、负极阻抗的越大；正极活性物质层和负极活性物质层的厚度越大，正极和负极的阻抗越大；正极极片和负极极片的压实密度越大，正极和负极的阻抗越大。Specifically, the factors affecting the impedance of the positive electrode and the negative electrode include: the composition and ratio of the positive active material layer, the composition and ratio of the negative electrode active material layer, the thickness of the positive electrode active material layer, the thickness of the negative electrode active material layer, the thickness of the positive electrode Compaction density, compaction density of negative pole piece, etc. For example, the lower the content of the conductive agent in the positive electrode active material layer and the negative electrode active material layer, the greater the impedance of the positive electrode and the negative electrode; the greater the thickness of the positive electrode active material layer and the negative electrode active material layer, the greater the impedance of the positive electrode and the negative electrode; The greater the compaction density of the pole piece and the negative pole piece, the greater the impedance of the positive electrode and the negative electrode.
具体地，欧姆内阻的影响因素有很多，包括但不限于，集流体的种类、厚度，极耳的厚度，隔离膜的种类、厚度、透气度等。Specifically, there are many factors affecting the ohmic internal resistance, including but not limited to the type and thickness of the current collector, the thickness of the tab, the type, thickness, and air permeability of the isolation membrane.
具体地，电解液阻抗的影响因素有很多，例如溶剂和锂盐的种类，溶剂和锂盐的配比，不同的溶剂会导致电解液粘度的差异，从而影响电解液的阻抗，导致阻抗分压的差异，最终影响电化学装置的输出电压平台。Specifically, there are many factors that affect the impedance of the electrolyte, such as the type of solvent and lithium salt, the ratio of the solvent and the lithium salt, and different solvents will cause differences in electrolyte viscosity, which will affect the electrolyte impedance and lead to impedance partial pressure. The difference ultimately affects the output voltage platform of the electrochemical device.
在本申请一些实施例中，I 0的值为10A。当I 0为10A时，电化学装置接近实际使用时的电流，可以获得电化学装置真实的使用状态，准确获得电化学装置实际使用时的阻抗分压的大小，从而使电化学装置在实际使用时的输出电压平台为3.55V至3.76V，而不会 出现因为阻抗分压评估得不准确而导致电化学装置的输出电压平台不在3.55V至3.76V的范围内的情况。 In some embodiments of the present application, the value of I 0 is 10A. When I 0 is 10A, the current of the electrochemical device is close to the actual use state, the true use state of the electrochemical device can be obtained, and the impedance partial pressure of the electrochemical device in actual use can be accurately obtained, so that the electrochemical device is in actual use When the output voltage platform is 3.55V to 3.76V, the output voltage platform of the electrochemical device will not be in the range of 3.55V to 3.76V due to the inaccurate assessment of the impedance partial pressure.
在本申请一些实施例中，R的值为1毫欧～30毫欧。当R的值在该范围内时，一方面电化学装置可以获得好的电化学性能(例如循环性能、快速充电性能)，另一方面对电化学装置的输出电压平台的影响较小，从而使电化学装置具有较好的综合性能。In some embodiments of the present application, the value of R is 1 milliohm to 30 milliohms. When the value of R is within this range, on the one hand, the electrochemical device can obtain good electrochemical performance (such as cycle performance, fast charging performance), and on the other hand, it has less influence on the output voltage platform of the electrochemical device, so that Electrochemical devices have good overall performance.
在本申请一些实施例中，R包括电化学装置的正极阻抗、负极阻抗、电解液阻抗和欧姆内阻。因为电化学装置的输出电压平台范围较小，如果R不考虑这些阻抗对输出电压平台的影响，正极和负极的电压平台即使满足输出电压平台的设计，微小的阻抗分压也会导致电化学装置的输出电压平台很难在3.55V至3.76V范围内，这是由于3.55V至3.76V的输出电压平台窗口很小导致的。In some embodiments of the present application, R includes the positive electrode impedance, the negative electrode impedance, the electrolyte impedance, and the ohmic internal resistance of the electrochemical device. Because the output voltage platform range of the electrochemical device is small, if R does not consider the impact of these impedances on the output voltage platform, even if the voltage platform of the positive and negative electrodes meets the design of the output voltage platform, the small impedance partial pressure will cause the electrochemical device The output voltage platform is difficult to be in the range of 3.55V to 3.76V, which is caused by the small output voltage platform window of 3.55V to 3.76V.
具体地，在本申请一些实施例中，正极活性物质包含磷酸铁锂或锰酸锂中的至少一种。磷酸铁锂和锰酸锂可以经过包覆和掺杂处理，例如碳包覆的磷酸铁锂，其中，由于磷酸铁锂或锰酸锂的成本较低，正极活性物质包含磷酸铁锂或锰酸锂中的至少一种可以显著的降低电化学装置及电池组的成本，从而具有广泛的市场竞争力。Specifically, in some embodiments of the present application, the positive active material includes at least one of lithium iron phosphate or lithium manganate. Lithium iron phosphate and lithium manganate can be coated and doped, such as carbon-coated lithium iron phosphate, where, due to the lower cost of lithium iron phosphate or lithium manganate, the positive electrode active material contains lithium iron phosphate or manganese acid At least one of lithium can significantly reduce the cost of electrochemical devices and battery packs, thereby having broad market competitiveness.
进一步地，在本申请一些实施例中，正极活性物质还包含镍钴锰酸锂或镍钴铝酸锂中的至少一种。其中，由于磷酸铁锂或锰酸锂的能量密度较低，而镍钴锰酸锂或镍钴铝酸锂的能量密度较高，故选择镍钴锰酸锂或镍钴铝酸锂，可以更近一步地提高电化学装置及电池组的能量密度。Further, in some embodiments of the present application, the positive electrode active material further includes at least one of lithium nickel cobalt manganate or lithium nickel cobalt aluminate. Among them, because the energy density of lithium iron phosphate or lithium manganate is lower, and the energy density of lithium nickel cobalt manganate or lithium nickel cobalt aluminate is higher, it is better to choose lithium nickel cobalt manganate or lithium nickel cobalt aluminate. Further improve the energy density of electrochemical devices and battery packs.
其中，镍钴锰酸锂或镍钴铝酸锂的化学式为：Li xCo yNi zM 1-y-zO bX b-a；其中，M为硼、镁、铝、硅、磷、硫、钛、铬、锰、铁、铜、锌、镓、锗、钇、锆、钼、银、钡、钨、铟、锡、铅、和锑中的一种或多种元素，x、y、z、a、b满足：0.8＜x≤1.2， 0<y≤0.5，0.5≤z<1.0，1-y-z>0，1.8≤b≤2.2，及0≤a≤1.0。 Among them, the chemical formula of lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminate is: Li x Co y Ni z M 1-yz O b X ba ; where M is boron, magnesium, aluminum, silicon, phosphorus, sulfur, titanium, One or more elements of chromium, manganese, iron, copper, zinc, gallium, germanium, yttrium, zirconium, molybdenum, silver, barium, tungsten, indium, tin, lead, and antimony, x, y, z, a , B satisfies: 0.8<x≤1.2, 0<y≤0.5, 0.5≤z<1.0, 1-yz>0, 1.8≤b≤2.2, and 0≤a≤1.0.
在本申请一些实施例中，正极活性物质层还包括第一粘结剂及导电剂。正极活性物质与第一粘结剂及导电剂混合。其中，导电剂和第一粘结剂为业界常用的可用于正极的导电剂和粘结剂。In some embodiments of the present application, the positive active material layer further includes a first binder and a conductive agent. The positive active material is mixed with the first binder and the conductive agent. Among them, the conductive agent and the first binder are commonly used in the industry and can be used for the positive electrode.
导电剂可以包括导电炭黑、石墨烯、碳纳米管、碳纤维或科琴黑中的至少一种。第一粘结剂可以选自聚偏氟乙烯、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。The conductive agent may include at least one of conductive carbon black, graphene, carbon nanotube, carbon fiber, or Ketjen black. The first binder can be selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, poly At least one of ethylene pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, or polyhexafluoropropylene.
在本申请一些实施例中，正极还包括正极集流体，正极活性物质层负载在正极集流体上。In some embodiments of the present application, the positive electrode further includes a positive electrode current collector, and the positive electrode active material layer is supported on the positive electrode current collector.
在本申请一些实施例中，负极活性物质包含人造石墨、天然石墨、软碳、硬碳、中间相碳微球、硅、硅合金、硅碳复合物、硅氧化合物、钛酸锂或钛酸铌中的至少一种。In some embodiments of the present application, the negative active material includes artificial graphite, natural graphite, soft carbon, hard carbon, mesocarbon microspheres, silicon, silicon alloy, silicon-carbon composite, silicon-oxygen compound, lithium titanate, or titanic acid At least one of niobium.
在本申请一些实施例中，负极活性物质层还包括第二粘结剂，第二粘结剂与负极活性物质混合。In some embodiments of the present application, the negative active material layer further includes a second binder, and the second binder is mixed with the negative active material.
在本申请一些实施例中，负极还包括负极集流体，负极活性物质层负载在负极集流体上。In some embodiments of the present application, the negative electrode further includes a negative electrode current collector, and the negative electrode active material layer is supported on the negative electrode current collector.
本申请的电化学装置对隔离膜的材料、结构等没有特殊限定。隔离膜包括，但不限于，选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、聚酰亚胺和芳纶中的至少一种。举例来说，聚乙烯包括选自高密度聚乙烯、低密度聚乙烯和超高分子量聚乙烯中的至少一种组分。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。The electrochemical device of the present application does not specifically limit the material, structure, etc. of the isolation membrane. The isolation film includes, but is not limited to, at least one selected from polyethylene, polypropylene, polyethylene terephthalate, polyimide, and aramid. For example, polyethylene includes at least one component selected from high-density polyethylene, low-density polyethylene, and 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.
隔离膜的表面还可包括多孔层，多孔层设置在隔离膜的至少一个表面上，多孔层包括无机颗粒和粘结剂中的一种或两种，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)、二氧化铈(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、氢氧化钙和硫酸钡中的一种或多种的组合。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、聚四氟乙烯和聚六氟丙烯中的一种或多种的组合。 The surface of the isolation membrane may also include a porous layer, the porous layer is provided on at least one surface of the isolation membrane, the porous layer includes one or two of 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 ), cerium oxide (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, calcium hydroxide And a combination of one or more of barium sulfate. The binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, polyvinyl pyrrole A combination of one or more of alkanone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, and polyhexafluoropropylene.
在本申请一些实施例中，电解液包括溶剂和锂盐，溶剂包含碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸乙丙酯、碳酸乙丁酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、碳酸亚乙烯酯或亚硫酸丙烯酯中的至少一种。In some embodiments of the present application, the electrolyte includes a solvent and a lithium salt, and the solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, and ethylene carbonate. At least one of ester, propylene carbonate, butylene carbonate, γ-butyrolactone, vinylene carbonate, or propylene sulfite.
在本申请一些实施例中，电解液还包括除上述以外的其他非水溶剂，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。In some embodiments of the present application, the electrolyte further includes other non-aqueous solvents other than the above, and the non-aqueous solvent may be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.
碳酸酯化合物可为环状碳酸酯化合物、氟代碳酸酯化合物或其组合。The carbonate compound may be a cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.
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。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。Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl ethylene carbonate (VEC), or a combination thereof. Examples of fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethyl, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, or a combination thereof.
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、癸内酯、戊内酯、甲 瓦龙酸内酯、己内酯、甲酸甲酯或者其组合。Examples of carboxylic acid ester compounds are methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, decanolide, valerolactone, methyl valerate Lonicolactone, caprolactone, methyl formate, or a combination thereof.
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。Examples of ether compounds are dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxy Methyl ethane, 2-methyltetrahydrofuran, tetrahydrofuran, or a combination thereof.
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、磷酸酯或者其组合。Examples of other organic solvents are dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, methyl Amide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, phosphate ester, or a combination thereof.
在本申请一些实施例中，锂盐包含六氟磷酸锂、四氟硼酸锂、六氟砷酸锂、高氯酸锂或三氟甲基磺酸锂中的至少一种。In some embodiments of the present application, the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, or lithium trifluoromethanesulfonate.
本申请还提供一种包括如上的电化学装置的电池组。电池组满足如下关系式：The present application also provides a battery pack including the above electrochemical device. The battery pack satisfies the following relationship:
U 总＝U 0*i  (式6)； U total = U 0 *i (Equation 6);
其中，V 总表示电池组的对外输出电压平台，单位为V，i表示电化学装置的个数；及U 总的值选自36、48、60、72、84或96中的一个，且U 总具有±0.5的偏差。 Among them, V total represents the external output voltage platform of the battery pack, the unit is V, i represents the number of electrochemical devices; and the value of U total is selected from one of 36, 48, 60, 72, 84 or 96, and U There is always a deviation of ±0.5.
应用多个本申请的电化学装置组成的电池组能够达到标准输出电压平台，不会影响电池组的使用，也不会导致成本的升高，从而应用多个本申请的电化学装置组成的电池组具有较低的成本。A battery pack composed of multiple electrochemical devices of the present application can reach a standard output voltage platform, without affecting the use of the battery pack, and will not cause an increase in cost, so that a battery composed of multiple electrochemical devices of the present application is applied The group has a lower cost.
以下通过具体实施例和对比例来对本申请进行说明。具体地，在如下具体实施例中涉及到的锂离子电池均是指电化学装置。The application will be described below through specific examples and comparative examples. Specifically, the lithium ion batteries involved in the following specific embodiments all refer to electrochemical devices.
实施例1Example 1
正极的制备：将磷酸铁锂(U 正1为3.3V)、锰酸锂(U 正2为4.02V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量28.8：67.2：0.8：0.8：2.4的比例(对应磷酸铁锂的质量占比，x 1为0.3，锰酸锂的质量占比，x 2为0.7)溶于N-甲基吡咯烷酮溶液中，形成正极浆料。采用铝 箔作为正极集流体(铝箔的厚度为16μm)，将正极浆料涂覆于正极集流体的两面上(涂布重量0.25kg/m 2)，经过干燥、冷压(正极的压实密度为3.5g/cm 3)、裁切后得到正极。 Preparation of positive electrode: Lithium iron phosphate (U+ 1 is 3.3V), lithium manganate (U+ 2 is 4.02V), conductive carbon black, carbon nanotubes, polyvinylidene fluoride by weight 28.8: 67.2: 0.8: The ratio of 0.8:2.4 (corresponding to the mass ratio of lithium iron phosphate, x 1 is 0.3, and the mass ratio of lithium manganate, x 2 is 0.7) is dissolved in the N-methylpyrrolidone solution to form a positive electrode slurry. Using aluminum foil as the positive electrode current collector (the thickness of the aluminum foil is 16μm), the positive electrode slurry is coated on both sides of the positive electrode current collector (coating weight 0.25kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.5g/cm 3 ), the positive electrode is obtained after cutting.
负极的制备:将人造石墨(U 负1为0.1V，y 1为1)、丁苯橡胶及羧甲基纤维素钠按重量比97.7：1.0：1.3的比例溶于去离子中，形成负极浆料。采用铜箔作为负极集流体(铜箔的厚度为8μm)，将负极浆料涂覆于负极集流体的两面上(涂布重量0.089kg/m 2)，经过干燥、冷压(负极的压实密度为1.6g/cm 3)、裁切后得到负极。 Preparation of negative electrode: Dissolve artificial graphite (U negative 1 is 0.1V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material. Copper foil is used as the negative electrode current collector (the thickness of the copper foil is 8μm), and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.089kg/m 2 ), after drying and cold pressing (compaction of the negative electrode) The density is 1.6 g/cm 3 ), and the negative electrode is obtained after cutting.
电解液的制备：在含水量小于10ppm的环境下，将六氟磷酸锂与非水有机溶剂按重量比10：90配制以形成电解液(锂盐浓度1mol/L)。其中，非水有机溶剂中各成分重量比为：碳酸乙烯酯：碳酸二乙酯：碳酸亚丙酯：丙酸丙酯：碳酸亚乙烯酯＝20：30：20：28：2。Preparation of electrolyte: In an environment with a water content of less than 10 ppm, lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 10:90 to form an electrolyte (lithium salt concentration 1 mol/L). Wherein, the weight ratio of each component in the non-aqueous organic solvent is: ethylene carbonate: diethyl carbonate: propylene carbonate: propyl propionate: vinylene carbonate=20:30:20:28:2.
隔离膜的制备：选用单层聚丙烯(厚度为14μm)作为隔膜，透气度为76s/100cm 3。 The preparation of the isolation membrane: a single-layer polypropylene (thickness of 14 μm) is selected as the membrane, and the air permeability is 76s/100cm 3 .
锂离子电池的制备：将上述负极、正极、隔离膜依顺序堆叠，使隔离膜处于正极与负极中间，起到隔离的作用，然后将堆叠后的正极、隔离膜及负极卷绕成电极组件，电极组件的每一圈具有1个极耳。随后将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，随后将上述电解液注入铝塑膜包装袋中，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备，获得的锂离子电池的阻抗R为2.5mΩ。Lithium-ion battery preparation: stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80℃, and then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 2.5 mΩ.
U 正＝x 1U 正1+x 2U 正2＝3.804V U positive = x 1 U positive 1 + x 2 U positive 2 ＝3.804V
U 负＝y 1U 负1＝0.1V U negative = y 1 U negative 1 = 0.1V
U r＝10A*2.5mΩ/1000＝0.025V U r ＝10A*2.5mΩ/1000＝0.025V
U 0＝U 正-U 负-U r＝3.68V U 0 ＝U positive- U negative- U r ＝3.68V
电池组的电压平台为47.84V，容量为20Ah，锂离子电池的数量为13个，对应锂离子电池的电压平台为3.68V，放电电流为10A。The voltage platform of the battery pack is 47.84V, the capacity is 20Ah, the number of lithium-ion batteries is 13, and the voltage platform corresponding to the lithium-ion battery is 3.68V, and the discharge current is 10A.
实施例2：Example 2:
正极的制备：将镍钴锰酸锂(Ni:Co:Mn＝5:2:3)(U 正1为3.69V)、磷酸铁锂(U 正2为3.3V)、锰酸锂(U 正3为4.02V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量比28.8：28.8：38.4：0.8：0.6：2.4的比例(对应镍钴锰三元的质量占比x 1为0.3，磷酸铁锂的质量占比x 2为0.3，锰酸锂的质量占比x 3为0.4)混合，制备过程如实施例1。 The preparation of the positive electrode: Lithium nickel cobalt manganate (Ni:Co:Mn=5:2:3) (U positive 1 is 3.69V), lithium iron phosphate (U positive 2 is 3.3V), lithium manganate (U positive 3 is 4.02V), conductive carbon black, carbon nanotubes, polyvinylidene fluoride by weight ratio of 28.8: 28.8: 38.4: 0.8: 0.6: 2.4 (corresponding to the mass ratio of nickel, cobalt and manganese ternary x 1 is 0.3 , The mass proportion of lithium iron phosphate x 2 is 0.3, and the mass proportion of lithium manganate x 3 is 0.4) mixing, and the preparation process is the same as in Example 1.
负极的制备：将人造石墨(U 负1为0.1V)、Si(U 负2为0.6V)、丁苯橡胶及羧甲基纤维素钠按重量比92.8：4.9：1.0：1.3的比例混合(对应人造石墨的质量占比y 1为0.95，Si的质量占比y 2为0.05)，制备过程如实施例1。 The preparation of the negative electrode: the artificial graphite (U minus 1 is 0.1V), Si (U minus 2 is 0.6V), styrene butadiene rubber and sodium carboxymethyl cellulose are mixed in a weight ratio of 92.8:4.9:1.0:1.3 ( Correspondingly, the mass proportion y 1 of artificial graphite is 0.95, and the mass proportion y 2 of Si is 0.05), and the preparation process is the same as in Example 1.
电解液的制备:制备过程如实施例1。Preparation of electrolyte: The preparation process is as in Example 1.
隔离膜的制备：选用单层聚乙烯(厚度为9μm)作为隔离膜，单面涂覆氧化铝和聚偏氟乙烯的浆料(配比为7：3)，获得的涂覆后的隔离膜的透气度85s/100cm 3。 Preparation of the isolation membrane: a single layer of polyethylene (thickness of 9μm) is selected as the isolation membrane, and a slurry of alumina and polyvinylidene fluoride is coated on one side (the ratio is 7:3), and the coated isolation membrane is obtained The air permeability is 85s/100cm 3 .
锂离子电池的制备：将上述负极、正极、隔离膜依顺序堆叠，使隔离膜处于正极与负极中间，起到隔离的作用，然后将堆叠后的正极、隔离膜及负极卷绕成电极组件，电极组件的每一圈具有1个极耳。随后将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，随后将上述电解液注入铝塑膜包装袋中，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备，获得的锂离子电池的阻抗R为3.0mΩ。Lithium-ion battery preparation: stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80℃, and then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 3.0 mΩ.
U 正＝x 1U 正1+x 2U 正2+x 3U 正3＝3.705V U positive = x 1 U positive 1 + x 2 U positive 2 + x 3 U positive 3 ＝3.705V
U 负＝y 1U 负1+y 2U 负2＝0.125V U minus =y 1 U minus 1 +y 2 U minus 2 ＝0.125V
U r＝10A*3.0mΩ/1000＝0.03V U r ＝10A*3.0mΩ/1000＝0.03V
U 0＝U 正-U 负-U r＝3.55V U 0 ＝U positive- U negative- U r ＝3.55V
电池组的电压平台为60.35V(在60±0.5V的范围内)，容量为20Ah，锂离子电池的数量为17个，对应锂离子电池的电压平台要求3.55V，放电电流为10A。The voltage platform of the battery pack is 60.35V (within the range of 60±0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 17, and the voltage platform corresponding to the lithium-ion battery requires 3.55V, and the discharge current is 10A.
实施例3：Example 3:
正极的制备：将磷酸铁锂(U 正1为3.3V)、锰酸锂(V 正2为4.02V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量比29.1：67.9：0.8：0.8：1.4(对应磷酸铁锂的质量占比x 1为0.3，锰酸锂的质量占比x 2为0.7)的比例溶于N-甲基吡咯烷酮溶液中，形成正极浆料。采用铝箔作为正极集流体(铝箔的厚度为10μm)，将正极浆料涂覆于正极集流体上(0.22kg/m 2)，经过干燥、冷压(正极的压实密度为3.6g/cm 3)、裁切后得到正极。 Preparation of the positive electrode: Lithium iron phosphate (U+ 1 is 3.3V), lithium manganate (V+ 2 is 4.02V), conductive carbon black, carbon nanotubes, polyvinylidene fluoride in a weight ratio of 29.1: 67.9: 0.8 ：0.8:1.4 (corresponding to the mass ratio of lithium iron phosphate x 1 being 0.3, and the mass ratio of lithium manganate x 2 being 0.7) dissolved in the N-methylpyrrolidone solution to form a positive electrode slurry. Using aluminum foil as the positive electrode current collector (the thickness of the aluminum foil is 10μm), the positive electrode slurry is coated on the positive electrode current collector (0.22kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.6g/cm 3 ). The positive electrode is obtained after cutting.
负极的制备：将天然石墨(U 负1为0.1V)、人造石墨(U 负2为0.1V)、丁苯橡胶及羧甲基纤维素钠按重量比30：67.7：1.0：1.3的比例溶于去离子中，形成负极浆料(对应天然石墨的质量占比y 1为0.31，人造石墨的质量占比y 2为0.69)。采用铜箔作为负极集流体，将负极浆料涂覆于负极集流体的两面上(涂布重量0.080kg/m 2)，经过干燥、冷压(负极的压实密度为1.62g/cm 3)、裁切程序后得到负极。 Preparation of negative electrode: Dissolve natural graphite (U minus 1 is 0.1V), artificial graphite (U minus 2 is 0.1V), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 30:67.7:1.0:1.3 In deionization, a negative electrode slurry is formed (corresponding to the mass ratio of natural graphite y 1 being 0.31, and the mass ratio of artificial graphite y 2 being 0.69). Copper foil is used as the negative electrode current collector, and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.080kg/m 2 ), dried and cold pressed (the compaction density of the negative electrode is 1.62g/cm 3 ) , The negative electrode is obtained after the cutting process.
电解液的制备：在含水量小于10ppm的环境下，将六氟磷酸锂与非水有机溶剂按重量比8：92配制以形成电解液(锂盐浓度1mol/L)。其中，非水有机溶剂中各成分重量比为：碳酸乙烯酯：碳酸二乙酯：碳酸亚丙酯：丙酸丙酯：碳酸亚乙烯酯＝20：30：20：28：2。Preparation of electrolyte: In an environment with a water content of less than 10 ppm, lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 8:92 to form an electrolyte (lithium salt concentration 1 mol/L). Wherein, the weight ratio of each component in the non-aqueous organic solvent is: ethylene carbonate: diethyl carbonate: propylene carbonate: propyl propionate: vinylene carbonate=20:30:20:28:2.
隔离膜的制备：选用聚丙烯/聚乙烯/聚丙烯三层复合隔膜(厚度 为16μm)，单面涂覆陶瓷，透气度200s/100cm 3。 The preparation of the isolation membrane: a polypropylene/polyethylene/polypropylene three-layer composite diaphragm (thickness of 16μm) is selected, one side is coated with ceramics, and the air permeability is 200s/100cm 3 .
锂离子电池的制备：如实施例1。获得的锂离子电池的阻抗R为4.5mΩ。Preparation of lithium ion battery: as in Example 1. The impedance R of the obtained lithium ion battery was 4.5 mΩ.
U 正＝x 1U 正1+x 2U 正2＝3.804V U positive = x 1 U positive 1 + x 2 U positive 2 ＝3.804V
U 负＝y 1U 负1+y 2U 负2＝0.1V U minus =y 1 U minus 1 +y 2 U minus 2 ＝0.1V
U r＝10A*4.5mΩ/1000＝0.045V U r ＝10A*4.5mΩ/1000＝0.045V
U 0＝U 正-U 负-U r＝3.659V U 0 ＝U positive- U negative- U r ＝3.659V
电池组的电压平台为47.567V(在48±0.5V的范围内)，容量为20Ah，锂离子电池的数量为13个，对应锂离子电池的平台电压为3.659V，放电电流为10A。The voltage platform of the battery pack is 47.567V (within the range of 48±0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 13, and the platform voltage corresponding to the lithium-ion battery is 3.659V, and the discharge current is 10A.
实施例4：Example 4:
正极的制备：将镍钴锰酸锂(Ni:Co:Mn＝1:1:1)(U 正1为3.6V)、锰酸锂(U 正2为3.9V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量比19.2：76.8：1：0.6：2.4的比例(对应镍钴锰酸锂的质量占比x 1为0.2，锰酸锂的质量占比x 2为0.8)溶于N-甲基吡咯烷酮溶液中，形成正极浆料。制备流程如实施例2。 Preparation of positive electrode: Lithium nickel cobalt manganate (Ni:Co:Mn=1:1:1) (U+ 1 is 3.6V), lithium manganate (U+ 2 is 3.9V), conductive carbon black, carbon nano The tube and polyvinylidene fluoride are dissolved in a weight ratio of 19.2:76.8:1:0.6:2.4 (corresponding to the weight ratio of nickel cobalt lithium manganate x 1 is 0.2, and the weight ratio of lithium manganate x 2 is 0.8) In the N-methylpyrrolidone solution, a positive electrode slurry is formed. The preparation process is as in Example 2.
负极的制备：如实施例1。其中，U 负1为0.1V，y 1为1。 The preparation of the negative electrode: as in Example 1. Among them, U minus 1 is 0.1V, and y 1 is 1.
电解液的制备：如实施例1。Preparation of electrolyte: as in Example 1.
隔离膜的制备：选用聚丙烯/聚乙烯/聚丙烯三层复合隔膜(厚度为16μm)，单面涂覆陶瓷，透气度200s/100cm 3。 The preparation of the isolation membrane: a polypropylene/polyethylene/polypropylene three-layer composite diaphragm (thickness of 16μm) is selected, one side is coated with ceramics, and the air permeability is 200s/100cm 3 .
锂离子电池的制备：如实施例1。获得的锂离子电池的阻抗R为3mΩ。Preparation of lithium ion battery: as in Example 1. The impedance R of the obtained lithium ion battery was 3 mΩ.
U 正＝x 1U 正1+x 2U 正2＝3.84V U positive = x 1 U positive 1 + x 2 U positive 2 ＝3.84V
U 负＝y 1U 负1＝0.1V U negative = y 1 U negative 1 = 0.1V
U r＝10A*3mΩ/1000＝0.03V U r ＝10A*3mΩ/1000＝0.03V
U 0＝U 正-U 负-U r＝＝3.71V U 0 ＝U positive- U negative- U r ＝＝3.71V
电池组的电压平台为48.23V(在48±0.5V的范围内)，容量为20Ah，锂离子电池的数量为13个，对应锂离子电池的平台电压为3.71V，放电电流为10A。The voltage platform of the battery pack is 48.23V (within the range of 48±0.5V), the capacity is 20Ah, the number of lithium-ion batteries is 13, and the platform voltage corresponding to the lithium-ion battery is 3.71V, and the discharge current is 10A.
实施例5：Example 5:
正极的制备：将镍钴锰酸锂(Ni:Co:Mn＝5:2:3)(U 正1为3.65V)、锰酸锂(U 正2为3.95V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量比19.2：76.8：1：0.6：2.4的比例(对应镍钴锰酸锂的质量占比x 1为0.2，锰酸锂的质量占比x 2为0.8)溶于N-甲基吡咯烷酮溶液中，形成正极浆料。制备流程如实施例1。 Preparation of the positive electrode: Lithium nickel cobalt manganese oxide (Ni:Co:Mn=5:2:3) (U positive 1 is 3.65V), lithium manganate (U positive 2 is 3.95V), conductive carbon black, carbon nano The tube and polyvinylidene fluoride are dissolved in a weight ratio of 19.2:76.8:1:0.6:2.4 (corresponding to the weight ratio of nickel cobalt lithium manganate x 1 is 0.2, and the weight ratio of lithium manganate x 2 is 0.8) In the N-methylpyrrolidone solution, a positive electrode slurry is formed. The preparation process is as in Example 1.
负极的制备：将人造石墨(U 负1为0.08V，y 1为1)、丁苯橡胶及羧甲基纤维素钠按重量比97.7：1.0：1.3的比例溶于去离子中，形成负极浆料。采用铜箔作为负极集流体(铜箔的厚度为8μm)，将负极浆料涂覆于负极集流体的两面上(涂布重量0.085kg/m 2)，经过干燥、冷压(负极的压实密度为1.61g/cm 3)、裁切后得到负极。 Preparation of negative electrode: Dissolve artificial graphite (U negative 1 is 0.08V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material. Using copper foil as the negative electrode current collector (the thickness of the copper foil is 8μm), the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.085kg/m 2 ), after drying and cold pressing (the negative electrode is compacted) The density is 1.61 g/cm 3 ), and the negative electrode is obtained after cutting.
电解液的制备：在含水量小于10ppm的环境下，将六氟磷酸锂与非水有机溶剂按重量比12.5：87.5配制以形成电解液(锂盐浓度1mol/L)。其中，非水有机溶剂中各成分重量比为：碳酸乙烯酯：碳酸二乙酯：碳酸亚丙酯：碳酸甲乙酯＝10：40：25：25。Preparation of electrolyte: In an environment with a water content of less than 10 ppm, lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 12.5:87.5 to form an electrolyte (lithium salt concentration 1 mol/L). Wherein, the weight ratio of each component in the non-aqueous organic solvent is: ethylene carbonate: diethyl carbonate: propylene carbonate: ethyl methyl carbonate=10:40:25:25.
隔离膜的制备：如实施例1。Preparation of isolation membrane: as in Example 1.
锂离子电池的制备：如实施例1。获得的锂离子电池的阻抗R为5mΩ。Preparation of lithium ion battery: as in Example 1. The impedance R of the obtained lithium ion battery was 5 mΩ.
U 正＝x 1U 正1+x 2U 正2＝3.89V N = x 1 U U n n 1 + x 2 U 2 = 3.89V
U 负＝y 1U 负1＝0.08V U negative = y 1 U negative 1 = 0.08V
U r＝10A*5mΩ/1000＝0.05V U r ＝10A*5mΩ/1000＝0.05V
U 0＝U 正-U 负-U r＝3.76V U 0 ＝U positive- U negative- U r ＝3.76V
电池组的电压平台为60.16V(在60±0.5V的范围内)，容量为 30Ah，锂离子电池的数量16个，对应锂离子电池的平台电压为3.76V，放电电流为10A。The voltage platform of the battery pack is 60.16V (within the range of 60±0.5V), the capacity is 30Ah, the number of lithium-ion batteries is 16, and the platform voltage corresponding to the lithium-ion battery is 3.76V, and the discharge current is 10A.
对比例1Comparative example 1
正极的制备：将磷酸铁锂(U 正1为3.3V)、导电炭黑、碳纳米管、聚偏二氟乙烯按重量96：0.8：0.8：2.4的比例(对应磷酸铁锂的质量占比，x 1为1)溶于N-甲基吡咯烷酮溶液中，形成正极浆料。采用铝箔作为正极集流体(铝箔的厚度为16μm)，将正极浆料涂覆于正极集流体的两面上(涂布重量0.25kg/m 2)，经过干燥、冷压(正极的压实密度为3.5g/cm 3)、裁切后得到正极。 Preparation of positive electrode: Lithium iron phosphate (U positive 1 is 3.3V), conductive carbon black, carbon nanotubes, polyvinylidene fluoride in a weight ratio of 96:0.8:0.8:2.4 (corresponding to the mass ratio of lithium iron phosphate , X 1 is 1) Dissolve in N-methylpyrrolidone solution to form positive electrode slurry. Using aluminum foil as the positive electrode current collector (the thickness of the aluminum foil is 16μm), the positive electrode slurry is coated on both sides of the positive electrode current collector (coating weight 0.25kg/m 2 ), after drying and cold pressing (the compaction density of the positive electrode is 3.5g/cm 3 ), the positive electrode is obtained after cutting.
负极的制备:将人造石墨(U 负1为0.1V，y 1为1)、丁苯橡胶及羧甲基纤维素钠按重量比97.7：1.0：1.3的比例溶于去离子中，形成负极浆料。采用铜箔作为负极集流体(铜箔的厚度为8μm)，将负极浆料涂覆于负极集流体的两面上(涂布重量0.089kg/m 2)，经过干燥、冷压(负极的压实密度为1.6g/cm 3)、裁切后得到负极。 Preparation of negative electrode: Dissolve artificial graphite (U negative 1 is 0.1V, y 1 is 1), styrene-butadiene rubber and sodium carboxymethyl cellulose in a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. material. Copper foil is used as the negative electrode current collector (the thickness of the copper foil is 8μm), and the negative electrode slurry is coated on both sides of the negative electrode current collector (coating weight 0.089kg/m 2 ), after drying and cold pressing (compaction of the negative electrode) The density is 1.6 g/cm 3 ), and the negative electrode is obtained after cutting.
电解液的制备：在含水量小于10ppm的环境下，将六氟磷酸锂与非水有机溶剂按重量比10：90配制以形成电解液(锂盐浓度1mol/L)。其中，非水有机溶剂中各成分重量比为：碳酸乙烯酯：碳酸二乙酯：碳酸亚丙酯：丙酸丙酯：碳酸亚乙烯酯＝20：30：20：28：2。Preparation of electrolyte: In an environment with a water content of less than 10 ppm, lithium hexafluorophosphate and a non-aqueous organic solvent are prepared at a weight ratio of 10:90 to form an electrolyte (lithium salt concentration 1 mol/L). Wherein, the weight ratio of each component in the non-aqueous organic solvent is: ethylene carbonate: diethyl carbonate: propylene carbonate: propyl propionate: vinylene carbonate=20:30:20:28:2.
隔离膜的制备：选用单层聚丙烯(厚度为14μm)作为隔膜，透气度为76s/100cm 3。 The preparation of the isolation membrane: a single-layer polypropylene (thickness of 14 μm) is selected as the membrane, and the air permeability is 76s/100cm 3 .
锂离子电池的制备：将上述负极、正极、隔离膜依顺序堆叠，使隔离膜处于正极与负极中间，起到隔离的作用，然后将堆叠后的正极、隔离膜及负极卷绕成电极组件，电极组件的每一圈具有1个极耳。随后将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，随后将上述电解液注入铝塑膜包装袋中，经过真空封装、静置、 化成、整形等工序，即完成锂离子电池的制备，获得的锂离子电池的阻抗R为5mΩ。Lithium-ion battery preparation: stack the above-mentioned negative electrode, positive electrode, and separator in order, so that the separator is located between the positive electrode and the negative electrode, and play a role of isolation, and then wind the stacked positive electrode, separator and negative electrode into an electrode assembly. Each circle of the electrode assembly has 1 tab. Then put the electrode assembly into the aluminum-plastic film packaging bag, and remove the water at 80℃, then inject the above electrolyte into the aluminum-plastic film packaging bag, and go through the processes of vacuum packaging, standing, forming, and shaping to complete the process. The lithium ion battery was prepared, and the impedance R of the obtained lithium ion battery was 5 mΩ.
U 正＝x 1U 正1＝3.3V U positive = x 1 U positive 1 = 3.3V
U 负＝y 1U 负1＝0.1V U negative = y 1 U negative 1 = 0.1V
U r＝10A*5mΩ/1000＝0.05V U r ＝10A*5mΩ/1000＝0.05V
U 0＝U 正-U 负-U r＝3.15V U 0 ＝U positive- U negative- U r ＝3.15V
锂离子电池的的电压平台为3.15V，当16个锂离子电池组成电池组时，输出电压平台为50.4V，当15个锂离子电池组成电池组时，输出电压平台为47.25V。对比例1和实施例1对比，对比例1无法达到标准输出电压平台48±0.5V。The voltage platform of the lithium-ion battery is 3.15V. When 16 lithium-ion batteries form a battery pack, the output voltage platform is 50.4V, and when 15 lithium-ion batteries form a battery pack, the output voltage platform is 47.25V. Comparing Comparative Example 1 with Example 1, Comparative Example 1 cannot reach the standard output voltage platform of 48±0.5V.
以上，仅是本申请的较佳实施方式而已，并非对本申请任何形式上的限制，虽然本申请已是较佳实施方式揭露如上，并非用以限定本申请，任何熟悉本专业的技术人员，在不脱离本申请技术方案范围内，当可利用上述揭示的技术内容做出些许更动或修饰为等同变化的等效实施方式，但凡是未脱离本申请技术方案内容，依据本申请的技术实质对以上实施方式所做的任何简单修改、等同变化与修饰，均仍属于本申请技术方案的范围内。The above are only the preferred embodiments of this application, and do not limit the application in any form. Although the preferred embodiments of this application are disclosed above, they are not intended to limit this application. Anyone familiar with the profession, Without departing from the scope of the technical solution of the present application, when the technical content disclosed above can be used to make some changes or modification into equivalent implementations with equivalent changes, provided that the content of the technical solution of the present application is not deviated from the content of the technical solution of the present application, the technical essence of the present application Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present application.

Claims (10)

  1. 一种电化学装置，其包括正极、负极、隔离膜及电解液，所述隔离膜设置于所述正极与所述负极之间；An electrochemical device, comprising a positive electrode, a negative electrode, a separator and an electrolyte, the separator being arranged between the positive electrode and the negative electrode;
    所述正极包括正极活性物质层，所述正极活性物质层包括n种正极活性物质；所述负极包括负极活性物质层，所述负极活性物质层包括m种负极活性物质；The positive electrode includes a positive electrode active material layer, the positive electrode active material layer includes n types of positive electrode active materials; the negative electrode includes a negative electrode active material layer, and the negative electrode active material layer includes m types of negative electrode active materials;
    其中，所述电化学装置的电压平台U 0满足如下关系式： Wherein, the voltage platform U 0 of the electrochemical device satisfies the following relationship:
    U 0＝U 正-U 负-U r  (式1)； U 0 ＝U positive- U negative- U r (Equation 1);
    U 正＝x 1U 正1+x 2U 正2+…..+x nU 正n  (式2)； U positive = x 1 U positive 1 + x 2 U positive 2 +…..+x n U positive n (Equation 2);
    U 负＝y 1U 负1+y 2U 负2+…..+y mU 负m  (式3)； U minus = y 1 U minus 1 +y 2 U minus 2 +...+y m U minus m (Equation 3);
    U r＝I 0*R  (式4)； U r =I 0 *R (Equation 4);
    3.55V≤U 0≤3.76V  (式5)； 3.55V≤U 0 ≤3.76V (Equation 5);
    其中，U 0表示所述电化学装置的电压平台，U 正表示所述正极的电压平台，U 负表示所述负极的电压平台，U r表示所述电化学装置的阻抗分压，x n表示第n种正极活性物质的质量在所有n种正极活性物质的总质量中所占的比例，U 正n表示第n种正极活性物质的电压平台，y m表示第m种负极活性物质的质量在所有m种负极活性物质的总质量中所占的比例，U 负m表示第m种负极活性物质的电压平台，I 0表示所述电化学装置的放电电流，R表示所述电化学装置的阻抗，n为正整数且大于或等于2，m为正整数且大于或等于1。 Where U 0 represents the voltage platform of the electrochemical device, U positive represents the voltage platform of the positive electrode, U negative represents the voltage platform of the negative electrode, U r represents the impedance partial pressure of the electrochemical device, and x n represents The ratio of the mass of the n-th positive active material to the total mass of all n positive active materials, U +n represents the voltage plateau of the n-th positive active material, and y m represents the mass of the m-th negative active material in The ratio of the total mass of all m negative active materials, U minus m represents the voltage plateau of the m-th negative active material, I 0 represents the discharge current of the electrochemical device, and R represents the impedance of the electrochemical device , N is a positive integer and greater than or equal to 2, and m is a positive integer and greater than or equal to 1.
  2. 如权利要求1所述的电化学装置，其中，所述I 0的值为10A。 The electrochemical device of claim 1, wherein the value of I 0 is 10A.
  3. 如权利要求1所述的电化学装置，其中，所述R的值为1毫欧～30毫欧。The electrochemical device according to claim 1, wherein the value of said R is 1 milliohm to 30 milliohms.
  4. 如权利要求1所述的电化学装置，其中，所述R包括所述电化学装置的正极阻抗、负极阻抗、电解液阻抗和欧姆内阻。The electrochemical device according to claim 1, wherein the R includes the positive electrode impedance, the negative electrode impedance, the electrolyte impedance, and the ohmic internal resistance of the electrochemical device.
  5. 如权利要求1所述的电化学装置，其中，所述正极活性物质包含磷酸铁锂或锰酸锂中的至少一种。The electrochemical device according to claim 1, wherein the positive electrode active material contains at least one of lithium iron phosphate or lithium manganate.
  6. 如权利要求5所述的电化学装置，其中，所述正极活性物质还包含镍钴锰酸锂或镍钴铝酸锂中的至少一种。The electrochemical device according to claim 5, wherein the positive electrode active material further contains at least one of lithium nickel cobalt manganate or lithium nickel cobalt aluminate.
  7. 如权利要求1所述的电化学装置，其中，所述负极活性物质包含人造石墨、天然石墨、软碳、硬碳、中间相碳微球、硅、硅合金、硅碳复合物、硅氧化合物、钛酸锂或钛酸铌中的至少一种。The electrochemical device according to claim 1, wherein the negative electrode active material comprises artificial graphite, natural graphite, soft carbon, hard carbon, mesophase carbon microspheres, silicon, silicon alloy, silicon-carbon composite, silicon-oxygen compound , At least one of lithium titanate or niobium titanate.
  8. 如权利要求1所述的电化学装置，其中，所述电解液包括溶剂和锂盐，所述溶剂包含碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸乙丙酯、碳酸乙丁酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、碳酸亚乙烯酯或亚硫酸丙烯酯中的至少一种。The electrochemical device according to claim 1, wherein the electrolyte includes a solvent and a lithium salt, and the solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene propyl carbonate, and ethyl butyl carbonate. At least one of ester, dipropyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, vinylene carbonate, or propylene sulfite.
  9. 如权利要求8所述的电化学装置，其中，所述锂盐包含六氟磷酸锂、四氟硼酸锂、六氟砷酸锂、高氯酸锂或三氟甲基磺酸锂中的至少一种。8. The electrochemical device according to claim 8, wherein the lithium salt contains at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, or lithium trifluoromethanesulfonate.
  10. 一种电池组，其中，所述电池组包括如权利要求1-9任一项所述的电化学装置，所述电池组满足如下关系式：A battery pack, wherein the battery pack includes the electrochemical device according to any one of claims 1-9, and the battery pack satisfies the following relational expression:
    U 总＝U 0*i  (式6)； U total = U 0 *i (Equation 6);
    其中，U 总表示所述电池组的对外输出电压平台，单位为V，i表示所述电化学装置的个数；及 Wherein, U always represents the external output voltage platform of the battery pack, the unit is V, and i represents the number of the electrochemical devices; and
    U 总的值选自36、48、60、72、84或96中的一个，且所述U 总具有±0.5的偏差。 The value of U total is selected from one of 36, 48, 60, 72, 84, or 96, and the U total has a deviation of ±0.5.
PCT/CN2020/082358 2020-03-31 2020-03-31 Electrochemical device and battery pack WO2021195938A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2020/082358 WO2021195938A1 (en) 2020-03-31 2020-03-31 Electrochemical device and battery pack
CN202080001975.XA CN112335089A (en) 2020-03-31 2020-03-31 Electrochemical device and battery pack

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/082358 WO2021195938A1 (en) 2020-03-31 2020-03-31 Electrochemical device and battery pack

Publications (1)

Publication Number Publication Date
WO2021195938A1 true WO2021195938A1 (en) 2021-10-07

Family

ID=74301708

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/082358 WO2021195938A1 (en) 2020-03-31 2020-03-31 Electrochemical device and battery pack

Country Status (2)

Country Link
CN (1) CN112335089A (en)
WO (1) WO2021195938A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114024047A (en) * 2021-11-01 2022-02-08 东莞新能安科技有限公司 Electrochemical device, electronic device, charging device, management method, and storage medium
CN115398667A (en) * 2021-11-15 2022-11-25 宁德新能源科技有限公司 Electrode, method of manufacturing the same, electrochemical device, and electronic device
CN117219851A (en) * 2023-11-09 2023-12-12 宁德时代新能源科技股份有限公司 Sodium secondary battery and electricity utilization device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114203965B (en) * 2021-12-07 2024-01-30 远景动力技术(江苏)有限公司 Electrochemical device and electronic apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1921182A (en) * 2006-09-19 2007-02-28 天津力神电池股份有限公司 Computational method for hybrid anode material discharging platform used by lithium ion cell
CN101394006A (en) * 2008-11-07 2009-03-25 唐志建 Valve-free fully sealed lithium ionic cell
CN101887990A (en) * 2010-07-01 2010-11-17 濮阳市星驰电源制造有限公司 Lithium-ion secondary battery and manufacturing method thereof
CN104347846A (en) * 2013-07-26 2015-02-11 浙江南博电源科技有限公司 Preparation method for safety-improved nickel-cobalt lithium manganate positive electrode sheet
CN104931887A (en) * 2014-03-18 2015-09-23 株式会社东芝 Calculation apparatus and calculation method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1921182A (en) * 2006-09-19 2007-02-28 天津力神电池股份有限公司 Computational method for hybrid anode material discharging platform used by lithium ion cell
CN101394006A (en) * 2008-11-07 2009-03-25 唐志建 Valve-free fully sealed lithium ionic cell
CN101887990A (en) * 2010-07-01 2010-11-17 濮阳市星驰电源制造有限公司 Lithium-ion secondary battery and manufacturing method thereof
CN104347846A (en) * 2013-07-26 2015-02-11 浙江南博电源科技有限公司 Preparation method for safety-improved nickel-cobalt lithium manganate positive electrode sheet
CN104931887A (en) * 2014-03-18 2015-09-23 株式会社东芝 Calculation apparatus and calculation method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114024047A (en) * 2021-11-01 2022-02-08 东莞新能安科技有限公司 Electrochemical device, electronic device, charging device, management method, and storage medium
CN114024047B (en) * 2021-11-01 2024-05-14 东莞新能安科技有限公司 Electrochemical device, electronic device, charging device, management method, and storage medium
CN115398667A (en) * 2021-11-15 2022-11-25 宁德新能源科技有限公司 Electrode, method of manufacturing the same, electrochemical device, and electronic device
CN117219851A (en) * 2023-11-09 2023-12-12 宁德时代新能源科技股份有限公司 Sodium secondary battery and electricity utilization device
CN117219851B (en) * 2023-11-09 2024-03-15 宁德时代新能源科技股份有限公司 Sodium secondary battery and electricity utilization device

Also Published As

Publication number Publication date
CN112335089A (en) 2021-02-05

Similar Documents

Publication Publication Date Title
US11682765B2 (en) Electrode and electrochemical device including the same
WO2021195938A1 (en) Electrochemical device and battery pack
JP5640546B2 (en) Nonaqueous electrolyte secondary battery separator and nonaqueous electrolyte secondary battery
WO2022204967A1 (en) Electrochemical device and electronic device
JP2008097879A (en) Lithium ion secondary battery
WO2023098311A1 (en) Electrochemical device and electronic device
CN113066961B (en) Negative electrode sheet, electrochemical device, and electronic device
JP6121697B2 (en) Non-aqueous electrolyte battery
WO2023216473A1 (en) Electrochemical apparatus and electronic apparatus
JP2009129721A (en) Non-aqueous secondary battery
WO2022198577A1 (en) Electrochemical device and electronic device
KR20190047203A (en) Positive electrode active material for lithium secondary battery, preparing method of the same, positive electrode and lithium secondary battery including the same
CN114270578A (en) Electrochemical device and electronic device
JP2012043629A (en) Separator for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
CN110931874A (en) High-voltage-resistant lithium ion battery electrolyte and lithium ion battery
WO2023070989A1 (en) Electrochemical device and electronic device comprising same
WO2022001634A1 (en) Laminated composite battery having three lugs
US20110117448A1 (en) Non-aqueous electrolyte secondary battery
CN111164817A (en) Lithium ion secondary battery
JP2003297354A (en) Lithium secondary battery
US20120021282A1 (en) Positive electrode for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, and method for producing the same
BR112014031381B1 (en) HIGH VOLTAGE ACTIVE CATHODE MATERIAL AND ITS METHOD OF PREPARATION, LITHIUM SECONDARY BATTERY, AS WELL AS PACKAGE AND ELECTRIC VEHICLE INCLUDING SUCH BATTERY
WO2023039748A1 (en) Electrochemical device and electronic device
CN108028361B (en) Positive electrode for lithium ion secondary battery and lithium ion secondary battery
JP6709991B2 (en) Lithium ion secondary battery

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: 20929661

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: 20929661

Country of ref document: EP

Kind code of ref document: A1