CN113193199A - Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof - Google Patents

Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof Download PDF

Info

Publication number
CN113193199A
CN113193199A CN202110483733.5A CN202110483733A CN113193199A CN 113193199 A CN113193199 A CN 113193199A CN 202110483733 A CN202110483733 A CN 202110483733A CN 113193199 A CN113193199 A CN 113193199A
Authority
CN
China
Prior art keywords
graphene
lithium ion
component
ion conductor
conductor material
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
CN202110483733.5A
Other languages
Chinese (zh)
Inventor
马池
刘兆平
秦志鸿
贺志龙
刘鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ningbo Institute of Material Technology and Engineering of CAS
Original Assignee
Ningbo Institute of Material Technology and Engineering of CAS
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 Ningbo Institute of Material Technology and Engineering of CAS filed Critical Ningbo Institute of Material Technology and Engineering of CAS
Priority to CN202110483733.5A priority Critical patent/CN113193199A/en
Publication of CN113193199A publication Critical patent/CN113193199A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • 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

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to graphene-lithium ion conductor material composite conductive slurry, and a preparation method and application thereof. The graphene-lithium ion conductor material composite conductive slurry is prepared from raw materials comprising a component a, a component b and an organic solvent; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material; the component b comprises graphene. In the graphene-lithium ion conductor material composite conductive slurry, the nanoscale phosphate component is uniformly dispersed among all graphene thin layers, and the graphene thin layers form barriers. The composite conductive slurry can effectively inhibit the overlapping effect and agglomeration between graphene thin layers, improves the dispersibility and stability of the composite conductive slurry, improves the conductivity of the phosphate component by the graphene, improves the ionic conductivity and the electrochemical performance of the component, namely, the phosphate and conductive carbon such as the graphene have synergistic effect, and improves the comprehensive performance of the composite conductive slurry.

Description

Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to graphene-lithium ion conductor material composite conductive slurry, and a preparation method and application thereof.
Background
Lithium ion batteries have the characteristics of high energy density, long cycle life and the like, and are important energy storage devices in the fields of consumer electronics, pure electric vehicles and hybrid vehicles. At present, a large number of cathode materials for power lithium ion batteries mainly comprise spinel lithium manganate, a layered-structure ternary cathode material and an olivine phosphate cathode material.
The conductivity of the anode material is low, and a proper amount of conductive agent needs to be added among material particles to construct a compact conductive network, so that a rapid channel is provided for electron transmission. Conventionally, a large number of conductive materials are conductive graphite and conductive carbon black (containing acetylene black, SuperP-Li and the like), and in recent years, a composite conductive agent formed by compounding novel conductive materials such as carbon nanotubes and graphene or the novel conductive carbon with the conductive graphite, the conductive carbon black, conductive metal particles or nanowires has been developed well, wherein the compounding effect of the composite conductive agent with the graphene and the carbon nanotubes as components is obvious, but the graphene and the carbon nanotubes are both nanoscale high-grade carbon materials, and have the defects of large specific surface area and easy agglomeration to cause dispersion difficulty.
The lithium ion battery works on the principle of insertion and extraction of lithium ions, so a battery system consisting of a positive electrode, a negative electrode and electrolyte still needs to have good ionic conductivity, and along with the development of electric automobiles, the requirements on energy density and high-rate charge and discharge performance (fast charge and fast discharge) of the power battery lithium ion battery are higher and higher, and the safety problem is more and more prominent. Therefore, how to improve the ionic conductivity and safety of the lithium ion battery has received extensive attention from academia and industry.
The graphene conductive paste provided by the prior art is a mixture of pure graphene or graphene and other carbon materials in terms of components, that is, graphene components (including graphene oxide and intercalated exfoliated graphene) and other conductive carbons (such as sp, cnt, acetylene black and the like, and graphite materials) are dispersed in a solvent to form a composite conductive paste. For example, chinese patent CN109728301A describes a lithium battery conductive paste containing graphene composed of graphene one prepared by redox method and graphene two prepared by liquid phase exfoliation method; chinese patent CN201811606781.3 provides that two or more kinds of graphene with different defects improve the lithium ion conduction of the conductive paste by utilizing the defects and the porous characteristics of the graphene; in addition, the improved scheme is to add other conductive components (non-conductive carbon materials) on the basis of the existing conductive paste, for example, chinese patent CN107393622B reports a composite conductive agent, which includes a graphene material and a modified titanium oxide material, wherein the surface of the modified titanium oxide material has hydroxyl groups, and the modified titanium oxide material is tightly compounded with the graphene material. Therefore, the prior art scheme basically focuses on the conductive function of the conductive material, so that the application of the conductive paste is improved, the function is single, and the defects that the conductivity and the safety performance of the lithium ion cannot be improved exist.
In addition, the prior art is more focused on improvement of a preparation method of the slurry and innovation of preparation equipment in the technical scheme, and aims to solve the problems of large surface area and easy agglomeration of a nano carbon material in the graphene composite slurry. For example, chinese patent CN109903931A provides a graphene composite conductive paste, which is prepared by preparing a graphene slurry, adding the graphene slurry into the prepared conductive dispersant slurry, adding the prepared binder glue solution, and performing grinding dispersion treatment to obtain a composite conductive paste, wherein the paste is described to have good dispersibility; chinese patent CN201710548191.9 describes a dispersion preparation method by sequentially treating different components by stirring, grinding, shearing and the like, and provides an clashing device "clashing two high-pressure liquid streams in coaxial opposite flow channels".
Disclosure of Invention
In view of this, the technical problem to be solved by the present invention is to provide a graphene-lithium ion conductor material composite conductive paste, a preparation method and an application thereof.
The invention provides graphene-lithium ion conductor material composite conductive slurry which is prepared from raw materials comprising a component a, a component b and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component b comprises graphene.
Preferably, the compound is prepared from raw materials comprising a component a, a component c and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component c is graphene composite slurry comprising a component b and a dispersant;
the component b comprises graphene.
Preferably, the component a accounts for 15-40% of the total mass of the raw materials, and the component b accounts for 2-4.5% of the total mass of the raw materials;
the lithium ion conductor material comprises LiMnPO4、LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4、Li3PO4、LiTi2(PO4)3And LiFePO4One or two of them;
in the carbon-coated lithium ion conductor material, the mass content of carbon is 1-3%;
the organic solvent comprises N-methyl pyrrolidone, dimethyl acetamide, N-dimethyl formamide or dimethyl sulfoxide.
Preferably, the component b comprises graphene and a conductive material;
the graphene is single-atom layer graphite or graphene nanosheets with 2-15 atomic layers;
the conductive material includes at least one of conductive graphite, conductive carbon black, acetylene black, SuperP-Li, carbon nanotubes, carbon nanofibers, and Ketjen black.
Preferably, the raw material further comprises a dispersant;
the dispersant accounts for 0.2 to 1 percent of the total mass of the raw materials;
the dispersing agent comprises one or two of polyvinylpyrrolidone, polyvinyl alcohol, Pluronic F127, Pluronic P123 and polyoxyethylene lauryl ether.
The invention also provides a preparation method of the graphene-lithium ion conductor material composite conductive slurry, which comprises the following steps:
A1) grinding the component a until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B1) mixing the components obtained in the step A1) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising a component b and an organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene.
The invention also provides a preparation method of the graphene-lithium ion conductor material composite conductive slurry, which comprises the following steps:
A2) grinding the component a and part of the organic solvent until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B2) mixing the components obtained in the step A2) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising the component b and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
or the conductive mixed slurry is prepared by mixing raw materials comprising the component c and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene;
the component c is graphene composite slurry comprising the component b and a dispersant.
The invention also provides a lithium ion battery positive plate which is characterized in that the lithium ion battery positive plate is prepared by uniformly mixing raw materials comprising a positive material, composite conductive slurry and a binder and coating the mixture on a current collector;
the positive electrode material comprises one or two of lithium cobaltate, spinel lithium manganate, layered lithium nickel cobaltate, spinel lithium nickel manganate, a Rich manganese-based material, layered lithium nickel cobalt manganate, a ternary material and lithium vanadate;
the composite conductive slurry is the graphene-lithium ion conductor material composite conductive slurry or the graphene-lithium ion conductor material composite conductive slurry prepared by the preparation method.
Preferably, in the raw materials, the mass content of the composite conductive paste is 0.5-30%.
The invention also provides a lithium ion battery which is characterized by comprising a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the positive electrode comprises the lithium ion battery positive plate.
The invention provides graphene-lithium ion conductor material composite conductive slurry which is prepared from raw materials comprising a component a, a component b and an organic solvent; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material; the component b comprises graphene; or the graphene-lithium ion conductor material composite conductive slurry is prepared from raw materials comprising a component a, a component c and an organic solvent; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material; the component c is graphene composite slurry comprising a component b and a dispersant; the component b comprises graphene. In the graphene-lithium ion conductor material composite conductive slurry, the nanoscale phosphate component is uniformly dispersed among all graphene thin layers, and the graphene thin layers form barriers. The composite conductive slurry can effectively inhibit the overlapping effect and agglomeration between graphene thin layers, improves the dispersibility and stability of the composite conductive slurry, improves the conductivity of a phosphate component by the graphene, improves the ionic conductivity and the electrochemical performance of the component, namely, the phosphate and conductive carbon such as the graphene have a synergistic effect, improves the comprehensive performance of the composite conductive slurry, and simultaneously, the lithium ion battery prepared from the graphene composite conductive slurry has higher safety performance.
Drawings
FIG. 1 is a process diagram for preparing graphene-lithium ion conductor material composite conductive paste according to embodiments 1 to 6 of the present invention;
fig. 2 is a process diagram for preparing the graphene-lithium ion conductor material composite conductive paste according to embodiment 7 of the present invention;
FIG. 3 is a process diagram for preparing the graphene-lithium ion conductor material composite conductive paste according to embodiments 8 to 10 of the present invention;
fig. 4 is an SEM image of the graphene-lithium ion conductor material composite conductive paste according to example 3 of the present invention;
FIG. 5 is a graph showing a particle size distribution of the fraction obtained in step 1) of comparative example 1 according to the present invention;
FIG. 6 is a graph showing a particle size distribution of the fraction obtained in step 1) of comparative example 2 of the present invention;
fig. 7 is an SEM image of a positive electrode sheet prepared from the graphene-lithium ion conductor material composite conductive paste of example 6 of the present invention;
fig. 8 is a charge-discharge curve of a CR2032 button cell prepared from the graphene-lithium ion conductor material composite conductive paste of example 8 and comparative example 4 according to the present invention;
fig. 9 is an ac impedance test chart of 2032 type button cell prepared from graphene-lithium ion conductor material composite conductive pastes of comparative example 3, example 5 and example 8;
fig. 10 is a discharge specific capacity curve diagram of the button cell battery of example 15 of the present invention at different rates.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides graphene-lithium ion conductor material composite conductive slurry which is prepared from raw materials comprising a component a, a component b and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component b comprises graphene.
In certain embodiments of the invention, the lithium ion conductor material is a nanoscale phosphate, specifically including Li1.5Al0.5Ge1.5PO4、Li3PO4、LiFePO4、LiMnPO4、LiMnxFeyPO4(x+y＝1)、LiTi2(PO4)3、Li3V2(PO4)3、Li1.5Al0.5Ti1.5(PO4)3One or two of them. The LiMnxFeyPO4(x + y ═ 1) may be LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4Or LiMn0.80Fe0.2PO4. Preferably, the lithium ion conductor material includes LiMnPO4、LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4、Li3PO4、LiTi2(PO4)3And LiFePO4One or two of them. The invention limits the specific components of the lithium ion conductor material, and can further ensure that the pole piece has better implementation effect.
The source of the lithium ion conductor material is not particularly limited, the lithium ion conductor material can be generally commercially available, and can also be prepared according to the preparation methods disclosed in application numbers 201110271031.7, 201210473364.2, 201210551815.X, 201210556657.7 or 201110146671.5 respectively. In certain embodiments of the invention, LiFePO4And LiMnxFeyPO4(x + y ═ 1) from Ningbo lithium-rich battery materials science and technology, Inc., containing 2.5 wt% to 2.8 wt% of cracked carbon. In certain embodiments of the invention, Li3PO4From the group of pharmaceutical chemicals; LiTi2(PO4)3And Li1.5Al0.5Ti1.5(PO4)3Is from Shanghai Zi-reagent factory.
In some embodiments of the present invention, the carbon-coated lithium ion conductor material contains carbon in an amount of 0% to 5% by mass. In some embodiments, the carbon-coated lithium ion conductor material contains carbon in an amount of 1% to 3% by mass. In some embodiments of the present invention, the carbon-coated lithium ion conductor material is carbon-coated LiFePO4Or carbon-coated LiMnxFeyPO4(x + y ═ 1). The carbon-coated LiMnxFeyPO4LiMn in (x + y ═ 1)xFeyPO4(x + y ═ 1) may be LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4Or LiMn0.80Fe0.2PO4. In some embodiments of the present invention, the carbon-coated lithium ion conductor material is available from Ningbo lithium-rich battery materials technologies, Inc.
In certain embodiments of the invention, component a comprises 15% to 40% or 20% to 35% of the total mass of the feedstock. In certain embodiments, the component a comprises 23.5%, 21.1%, 30%, 25%, 38%, or 27% of the total mass of the feedstock.
In the invention, the component b comprises graphene.
In certain embodiments of the present invention, the graphene is a monoatomic layer of graphite or a graphene nanoplatelet with 2-15 atomic layers.
In certain embodiments of the present invention, the component b comprises graphene and a conductive material;
the graphene is single-atom layer graphite or graphene nanosheets with 2-15 atomic layers;
the conductive material includes at least one of conductive graphite, conductive carbon black, acetylene black, SuperP-Li, carbon nanotubes, carbon nanofibers, and Ketjen black.
In some embodiments of the invention, the mass ratio of the graphene to the conductive material is 3-5: 0.5 to 2. In certain embodiments, the mass ratio of the graphene to the conductive material is 4: 1.
the preparation method of the graphene is not particularly limited, and a preparation method of the graphene known to those skilled in the art may be adopted. In certain embodiments of the present invention, the graphene may be prepared according to the preparation method of graphene disclosed in application No. 201410277206.9 or 201310131702.9.
In certain embodiments of the invention, component b comprises 2% to 4.5% or 2.5% to 4% of the total mass of the feedstock. In certain embodiments, the component b comprises 3.5%, 3%, 4%, 2.5%, or 2% of the total mass of the feedstock.
In certain embodiments of the invention, the organic solvent comprises N-methylpyrrolidone, dimethylacetamide, N-dimethylformamide, or dimethylsulfoxide.
In certain embodiments of the invention, the feedstock further comprises a dispersant.
In certain embodiments of the invention, the dispersant comprises one or both of polyvinylpyrrolidone, polyvinyl alcohol, fluoroscope F127, fluoroscope P123, and polyoxyethylene lauryl ether. Preferably, the dispersant comprises a first dispersant selected from one of polyvinylpyrrolidone and polyvinyl alcohol and a second dispersant selected from one of fluoroscope F127, fluoroscope P123 and polyoxyethylene lauryl ether. In certain embodiments of the present invention, the mass ratio of the first dispersant to the second dispersant is 1: 1.
in certain embodiments of the invention, the dispersant comprises 0.2% to 1% or 0.5% to 0.8% of the total mass of the feedstock. In embodiments, the dispersant comprises 0.4%, 0.8%, 0.6%, 0.55%, 0.35%, or 0.5% of the total mass of the feedstock.
The invention can effectively improve the dispersibility of the conductive material in the solvent and the stability of the slurry by limiting the content of the dispersant, and excessive addition has a limit on improving the dispersibility and the stability and can reduce the conductivity of the composite conductive slurry.
The invention also provides graphene-lithium ion conductor material composite conductive slurry which is prepared from the raw materials comprising the component a, the component c and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component c is graphene composite slurry comprising a component b and a dispersant;
the component b comprises graphene.
In certain embodiments of the invention, the lithium ion conductor material is a nanoscale phosphate, specifically including Li1.5Al0.5Ge1.5PO4、Li3PO4、LiFePO4、LiMnPO4、LiMnxFeyPO4(x+y＝1)、LiTi2(PO4)3、Li3V2(PO4)3、Li1.5Al0.5Ti1.5(PO4)3One or two of them. The LiMnxFeyPO4(x + y ═ 1) may be LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4Or LiMn0.80Fe0.2PO4. Preferably, the lithium ion conductor material includes LiMnPO4、LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4、Li3PO4、LiTi2(PO4)3And LiFePO4One or two of them. The invention limits the specific components of the lithium ion conductor material, and can further ensure that the pole piece has better implementation effect.
In the present invention, the source of the lithium ion conductor material is not particularly limited, and the lithium ion conductor material may be generally commercially available, or may be 20111 according to the application number0271031.7, 201210473364.2, 201210551815.X, 201210556657.7 or 201110146671.5. In certain embodiments of the invention, LiFePO4And LiMnxFeyPO4(x + y ═ 1) from Ningbo lithium-rich battery materials science and technology, Inc., containing 2.5 wt% to 2.8 wt% of cracked carbon. In certain embodiments of the invention, Li3PO4From the group of pharmaceutical chemicals; LiTi2(PO4)3And Li1.5Al0.5Ti1.5(PO4)3Is from Shanghai Zi-reagent factory.
In some embodiments of the present invention, the carbon-coated lithium ion conductor material contains carbon in an amount of 0% to 5% by mass. In some embodiments, the carbon-coated lithium ion conductor material contains carbon in an amount of 1% to 3% by mass. In some embodiments of the present invention, the carbon-coated lithium ion conductor material is carbon-coated LiFePO4Or carbon-coated LiMnxFeyPO4(x + y ═ 1). The carbon-coated LiMnxFeyPO4LiMn in (x + y ═ 1)xFeyPO4(x + y ═ 1) may be LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4Or LiMn0.80Fe0.2PO4. In some embodiments of the present invention, the carbon-coated lithium ion conductor material is available from Ningbo lithium-rich battery materials technologies, Inc.
In certain embodiments of the invention, component a comprises 15% to 40% or 20% to 35% of the total mass of the feedstock. In certain embodiments, the component a comprises 20%, 16%, or 33% of the total mass of the feedstock.
In the invention, the component b comprises graphene.
In certain embodiments of the present invention, the graphene is a monoatomic layer of graphite or a graphene nanoplatelet with 2-15 atomic layers.
In certain embodiments of the present invention, the component b comprises graphene and a conductive material;
the graphene is single-atom layer graphite or graphene nanosheets with 2-15 atomic layers;
the conductive material includes at least one of conductive graphite, conductive carbon black, acetylene black, SuperP-Li, carbon nanotubes, carbon nanofibers, and Ketjen black.
In some embodiments of the invention, the mass ratio of the graphene to the conductive material is 3-5: 0.5 to 2. In certain embodiments, the mass ratio of the graphene to the conductive material is 4: 1.
the preparation method of the graphene is not particularly limited, and a preparation method of the graphene known to those skilled in the art may be adopted. In certain embodiments of the present invention, the graphene may be prepared according to the preparation method of graphene disclosed in application No. 201410277206.9 or 201310131702.9.
In certain embodiments of the invention, component b comprises 2% to 4.5% or 2.5% to 4% of the total mass of the feedstock. In certain embodiments, the component b comprises 2.8%, 2%, 1.6%, or 2.8% of the total mass of the feedstock.
In certain embodiments of the invention, the organic solvent comprises N-methylpyrrolidone, dimethylacetamide, N-dimethylformamide, or dimethylsulfoxide.
In certain embodiments of the invention, the dispersant comprises one or both of polyvinylpyrrolidone, polyvinyl alcohol, fluoroscope F127, fluoroscope P123, and polyoxyethylene lauryl ether. Preferably, the dispersant comprises a first dispersant selected from one of polyvinylpyrrolidone and polyvinyl alcohol and a second dispersant selected from one of fluoroscope F127, fluoroscope P123 and polyoxyethylene lauryl ether. In certain embodiments of the present invention, the mass ratio of the first dispersant to the second dispersant is 1: 1.
in certain embodiments of the invention, the dispersant comprises 0.2% to 1% or 0.5% to 0.8% of the total mass of the feedstock. In certain embodiments, the dispersant comprises 0.3%, 0.5%, 0.4%, or 0.7% of the total mass of the feedstock.
The invention can effectively improve the dispersibility of the conductive material in the solvent and the stability of the slurry by limiting the content of the dispersant, and excessive addition has a limit on improving the dispersibility and the stability and can reduce the conductivity of the composite conductive slurry.
The source of the component c is not particularly limited in the present invention, and the component c may be made by self or may be generally commercially available. In some embodiments of the present invention, the component c may be a graphene composite conductive additive paste manufactured by Ningbo ink science and technology Co., Ltd, model number CGS-3, the solvent is N-methylpyrrolidone, the solid content is about 5 wt%, the carbon content of graphene is about 4 wt%, and the dispersant is about 1 wt%.
In the graphene-lithium ion conductor material composite conductive slurry, the nanoscale phosphate component is uniformly dispersed among all graphene thin layers, and the graphene thin layers form barriers. The composite conductive slurry can effectively inhibit the overlapping effect and agglomeration between graphene thin layers, improves the dispersibility and stability of the composite conductive slurry, improves the conductivity of the phosphate component by the graphene, improves the ionic conductivity and the electrochemical performance of the component, namely, the phosphate and conductive carbon such as the graphene have synergistic effect, and improves the comprehensive performance of the composite conductive slurry.
The invention also provides a preparation method of the graphene-lithium ion conductor material composite conductive slurry, which comprises the following steps:
A1) grinding the component a until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B1) mixing the components obtained in the step A1) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising a component b and an organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene.
In the preparation method of the graphene-lithium ion conductor material composite conductive slurry, the components and the proportion of the adopted raw materials are the same as those in the above, and are not described again.
In some embodiments of the present invention, component a is ground to a median particle size of 200 to 300 nm. In certain embodiments, the method of milling may be ball milling.
The cost is increased when the particle size of the component a is too small, and the composite conductive slurry obtained when the particle size is too large cannot well exert the synergistic effect with nano-carbon such as graphene, and is not beneficial to improving the conductivity and safety of lithium ions. In general, the median particle size of the phosphate raw material is large (> 1 μm), and it is necessary to make the particle size fine.
In some embodiments of the present invention, the raw material of the conductive mixed paste further includes a dispersant. The components and the proportion of the dispersant are the same as above, and are not described again.
In some embodiments of the invention, the ultrasonic frequency of the ultrasonic treatment is 10 to 45KHz, and the time is 15 to 40 min. In certain embodiments, the ultrasonic frequency of the ultrasonic treatment is 30KHz, and the time is 25 min.
In certain embodiments of the present invention, the mechanical mixing device is selected from one or more of a blender, a high speed disperser, a high speed emulsifier, a homogenizer, and a ball mill.
The invention also provides a preparation method of the graphene-lithium ion conductor material composite conductive slurry, which comprises the following steps:
A2) grinding the component a and part of the organic solvent until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B2) mixing the components obtained in the step A2) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising the component b and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
or the conductive mixed slurry is prepared by mixing raw materials comprising the component c and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene;
the component c is graphene composite slurry comprising the component b and a dispersant.
In the preparation method of the graphene-lithium ion conductor material composite conductive slurry, the components and the proportion of the adopted raw materials are the same as those in the above, and are not described again.
The present invention is not limited to any particular ratio of the amount of the organic solvent to the amount of the remaining organic solvent.
In certain embodiments of the present invention, component a and a portion of the organic solvent are milled to a median particle size of 200 to 300 nm. In certain embodiments, the method of milling may be ball milling.
The cost is increased when the particle size of the component a is too small, and the composite conductive slurry obtained when the particle size is too large cannot well exert the synergistic effect with nano-carbon such as graphene, and is not beneficial to improving the conductivity and safety of lithium ions. In general, the median particle size of the phosphate raw material is large (> 1 μm), and it is necessary to make the particle size fine.
In certain embodiments of the present invention, the mechanical mixing device is selected from one or more of a blender, a high speed disperser, a high speed emulsifier, a homogenizer, and a ball mill.
In certain embodiments of the invention, the time for sonication or mechanical mixing is 10 min.
The preparation method of the graphene-lithium ion conductor material composite conductive slurry provided by the invention is simple, has the advantages of short process and high efficiency, and can realize industrial batch production and application.
The invention also provides a lithium ion battery positive plate which is prepared by uniformly mixing the raw materials comprising the positive material, the composite conductive slurry and the binder and coating the mixture on a current collector;
the positive electrode material comprises one or two of lithium cobaltate, spinel lithium manganate, layered lithium nickel cobaltate, spinel lithium nickel manganate, layered lithium-rich lithium nickel manganate, layered lithium nickel cobalt manganate, a ternary material and lithium vanadate;
the composite conductive slurry is the graphene-lithium ion conductor material composite conductive slurry or the graphene-lithium ion conductor material composite conductive slurry prepared by the preparation method.
In certain embodiments of the present invention, the positive electrode material may be at least one of NCM523, NCM622, and NCM 811.
In some embodiments of the present invention, in the lithium ion battery positive plate, the mass content of the composite conductive paste is 0.5% to 30%.
In some embodiments of the present invention, the positive electrode sheet of the lithium ion battery is prepared according to the following method:
and uniformly mixing the positive electrode material, the composite conductive slurry and the binder, coating the uniformly mixed slurry on a current collector, drying, and punching to obtain the positive electrode plate of the lithium ion battery.
In the preparation method of the lithium ion battery positive plate, the raw material components and the proportion are the same as above, and are not described again.
In certain embodiments of the present invention, the binder is polyvinylidene fluoride.
In some embodiments of the invention, the mass ratio of the positive electrode material, the composite conductive paste and the binder is 92: 4: 4.
in certain embodiments of the invention, the blending is performed in a planetary blender.
In certain embodiments of the invention, the current collector is an aluminum foil current collector.
The invention also provides a lithium ion battery which is characterized by comprising an anode, a cathode, a diaphragm and electrolyte, wherein the anode is the lithium ion battery anode plate.
In some embodiments of the invention, the negative electrode is a metallic lithium sheet, the separator is a Celgard 2400 type separator, and the electrolyte is LiPF containing 1mol/L6The EC/DMC/EMC solution of (1), wherein the volume ratio of EC, DMC and EMC is 1: 1: 1.
in certain embodiments of the invention, the lithium ion battery is assembled according to the following method:
a metal lithium sheet is taken as a cathode, a Celgard 2400 type diaphragm is taken as a diaphragm, and the electrolyte is LiPF containing 1mol/L6The positive electrode, the negative electrode, the separation membrane and the electrolyte are assembled into a CR2032 button cell in a German Braun Lab type inert glove box (the water and oxygen content is less than 1 ppm).
The source of the above-mentioned raw materials is not particularly limited, and the raw materials may be generally commercially available.
The common conductive paste generally only has a conductive effect, the composite conductive paste is a mixed conductor of lithium ions and electrons, when the composite conductive paste is applied to a lithium ion secondary battery, carbon materials such as graphene in the paste form a three-dimensional conductive network in a battery pole piece, the effects of improving the electronic conductivity and rate capability of the pole piece are achieved, a phosphate component in the paste has high ionic conductivity and thermal stability, the composite conductive paste is endowed with the advantages of improving the lithium ion conductivity of a positive pole material body, improving the rate capability of the lithium ion battery and improving the safety performance of the prepared lithium battery (the possibility of thermal runaway of the lithium ion battery such as combustion and explosion is reduced); moreover, when the components containing manganese phosphate, lithium iron phosphate and the like in the composite conductive slurry are used for preparing the positive pole piece, the components can also provide part of capacity exertion, correspondingly reduce the battery capacity loss caused by inactive components, and enable the lithium ion battery to have higher energy density.
In order to further illustrate the present invention, the following describes in detail a graphene-lithium ion conductor material composite conductive paste, its preparation method and application with reference to the following examples, which should not be construed as limiting the scope of the present invention.
Examples 1 to 6
Weighing the raw material components according to the table 1;
step 1): mixing the component A with part of the organic solvent D, and reducing the particle size to 200-500 nm of median particle size by adopting a ball milling mode;
step 2): preparing conductive slurry: and weighing the component B powder and the component C, adding the component B powder and the component C into the residual organic solvent D, and mixing in a high-speed dispersion machine to form black slurry, namely the graphene conductive slurry.
Step 3): mixing the components treated in the step 1) with the graphene conductive slurry treated in the step 2), and treating for 10min by using a high-speed emulsifying machine to obtain the graphene-lithium ion conductor material composite conductive slurry.
Fig. 1 is a process diagram for preparing graphene-lithium ion conductor material composite conductive paste according to embodiments 1 to 6 of the present invention.
Example 7
Weighing the raw material components according to the table 1;
step 1): reducing the particle size of the component A to 200-500 nm of median particle size by adopting a ball milling mode;
step 2): preparing conductive slurry: weighing the component B powder and the component C, adding the component B powder and the component C into the organic solvent D, and mixing in a high-speed dispersion machine to form black slurry, namely graphene conductive slurry.
Step 3): mixing the components treated in the step 1) with the graphene conductive slurry treated in the step 2), and treating for 10min by using a high-speed emulsifying machine to obtain the graphene-lithium ion conductor material composite conductive slurry.
Fig. 2 is a process diagram for preparing the graphene-lithium ion conductor material composite conductive paste according to embodiment 7 of the present invention.
Examples 8 to 10
Weighing the raw material components according to the table 1;
step 1): mixing the component A with part of the organic solvent D, and reducing the particle size to 200-500 nm of median particle size by adopting a ball milling mode;
step 2): preparing conductive slurry: weighing slurry (graphene composite conductive additive slurry of CGS-3 type produced by Ningbo ink science and technology Co., Ltd.) containing component B powder and component C, adding into the residual organic solvent D, and mixing in a high-speed dispersion machine to form black slurry, namely graphene conductive slurry.
Step 3): mixing the components treated in the step 1) with the graphene conductive slurry treated in the step 2), and treating for 10min by using a high-speed emulsifying machine to obtain the graphene-lithium ion conductor material composite conductive slurry.
FIG. 3 is a process diagram for preparing the graphene-lithium ion conductor material composite conductive paste according to embodiments 8 to 10 of the present invention.
Table 1 shows the raw material components and contents used in examples 1 to 10 of the present invention.
TABLE 1 raw material components and contents used in examples 1 to 10 of the present invention
Figure BDA0003049467880000141
In table 1, the mass content indicates the mass content of the corresponding component in the raw material, component B only lists components other than graphene, and the mass ratio of the graphene to the components other than graphene in component B is 4: 1, the mass content of the component B comprises the mass content of graphene; in the embodiment 1, when the component A comprises two components of LP and LMFP75, the mass contents are 5.5 percent and 18 percent respectively; in the embodiment 10, the mass contents of the components LMFP75 and LATP are respectively 28% and 5%. Pluronic F127, Pluronic P123 and polyoxyethylene lauryl ether in the component C are represented by F127, P123 and O-20, and when the dispersant of the component C is selected from two combinations of the above substances, the mass ratio is 1: 1; furthermore, Li3PO4、Li1.5Al0.5Ti1.5(PO4)3、LiMn0.75Fe0.25PO4/C、LiMn0.6Fe0.4PO4/C、LiTi2(PO4)3、Li3V2(PO4)3、LiMn0.80Fe0.2PO4/C、LiFePO4/C、Li1.5Al0.5Ge1.5PO4Abbreviated as LP, LATP, LMFP75, LMP60, LTP, LVP, LMFP80, LFP, LAGP, respectively.
Example 11
The preparation process of the graphene-lithium ion conductor material composite conductive paste is different from that of the embodiment 4 only in that: in this example, component C is absent and the component masses are replaced by solvent D.
Comparative example 1
The preparation process of the graphene-lithium ion conductor material composite conductive paste is different from that of the embodiment 1 only in that: reducing the particle size in the step 1) to the median particle size of below 200 nm.
Comparative example 2
The preparation process of the graphene-lithium ion conductor material composite conductive paste is different from that of the embodiment 1 only in that: reducing the particle size in the step 1) to a median particle size of 600-800 nm.
Comparative example 3
The preparation process of the graphene-lithium ion conductor material composite conductive paste is different from that of the embodiment 2 only in that: the component A is not present in step 1), and the mass of the component A is replaced by a solvent D.
And (3) performance testing:
scanning analysis was performed on the graphene-lithium ion conductor material composite conductive paste prepared in example 3 using a Scanning Electron Microscope (SEM) of Coxem corporation or zeiss, and the result is shown in fig. 4. Fig. 4 is an SEM image of the graphene-lithium ion conductor material composite conductive paste according to example 3 of the present invention. The small grayish white particles in fig. 4 are LTP particles, the black lamellar layers are graphene and acetylene black, the LTP particles are dispersed among the graphene, and the conductive carbon materials such as graphene are well dispersed and not agglomerated.
Particle size distribution testing was performed with an OMEC LS-609 laser particle sizer, using water as the test medium. FIG. 5 is a graph showing a particle size distribution of the fraction obtained in step 1) of comparative example 1 according to the present invention. As can be seen from FIG. 5, the median particle size of the fraction obtained in step 1) of comparative example 1 was 170 nm.
FIG. 6 is a graph showing a particle size distribution of the fraction obtained in step 1) of comparative example 2 of the present invention. As can be seen from fig. 6, the median particle size of the fraction obtained in step 1) of comparative example 2 was 680 nm.
Example 12
The preparation method comprises the following steps of mixing a lithium ion battery positive electrode material (NCM523, tungsten building door industry), graphene-lithium ion conductor material composite conductive slurry and a polyvinylidene fluoride binder (Suwei 5130) according to a mass ratio of 92: 4: and 4, mixing, uniformly dispersing by using a planetary slurry mixer, coating on an aluminum foil current collector after uniform mixing, drying, and then punching and cutting into positive plates with the diameter of 1cm by using a punching machine. Celg with commercial graphite (F3C, Jiangxi purple light En science and technology Co., Ltd.) as negative electrodeard 2400 type 2400 diaphragm is a separation film, and the electrolyte is LiPF containing 1mol/L6The solution of EC/DMC/EMC (the volume ratio of EC, DMC and EMC is 1: 1: 1) is used as electrolyte to assemble the SAH flexible package battery.
Safety performance test (according to standard GB/T-31485):
the safety test items are briefly described as follows:
and (3) needling: a smooth steel needle of 6mm diameter was pierced through the fully charged cell at a rate of 2.2 cm/s.
And (3) overcharging: the fully charged pouch cell was charged to 1.5 times the end voltage at 1C current.
Extruding: the cell placed between the two plates was hydraulically stressed by means of a piston of 32mm diameter and was depressurized after 17.2 Mpa.
The graphene-lithium ion conductor material composite conductive pastes prepared in examples 1, 2, 6, 10 and 11 and comparative examples 1 to 3 were assembled into flexible packaging batteries according to the method of example 12, and the safety performance was tested. The results are shown in Table 2.
Table 2 safety performance test results for SAH flexible packaged batteries assembled in example 12
Acupuncture and moxibustion Overcharge Extrusion
Example 1 No obvious reaction No obvious reaction No obvious reaction
Example 2 No obvious reaction No obvious reaction No obvious reaction
Example 6 No obvious reaction No obvious reaction No obvious reaction
Example 10 No obvious reaction No obvious reaction No obvious reaction
Example 11 No obvious reaction No obvious reaction No obvious reaction
Comparative example 1 No obvious reaction No obvious reaction No obvious reaction
Comparative example 2 Slight smoking of the battery No obvious reaction No obvious reaction
Comparative example 3 After smoking, the fire is started After smoking, the fire is started Smoking
As can be seen from Table 2, the needling, overshoot and extrusion of examples 1, 2, 6, 10 and 11 and comparative example 1 all have no reaction and the test is passed; and the comparative example 2 is not passed through only needling, and the comparative example 3 is not passed through at all, wherein the comparative example 3 does not contain the phosphate component A, the proportion of the phosphate component A in the comparative example 2 is the same, but the median particle size is larger, only part of items are failed, and the test shows that the difference of the phosphate-containing component causes the difference of the safety test, so that the slurry has the function of improving the safety of the lithium ion battery. In addition, examples 3, 4, and 7-9 also have similar safety performance, and are not described herein.
Example 13
The preparation method comprises the following steps of mixing a lithium ion battery positive electrode material (NCM523, tungsten building door industry), graphene-lithium ion conductor material composite conductive slurry and a polyvinylidene fluoride binder (Suwei 5130) according to a mass ratio of 92: 4: and 4, mixing, uniformly dispersing by using a planetary slurry mixer, coating on an aluminum foil current collector after uniform mixing, drying, and then punching and cutting into positive plates with the diameter of 1cm by using a punching machine. A metal lithium sheet is taken as a cathode, a Celgard 2400 type diaphragm is taken as an isolating membrane, and the electrolyte is LiPF containing 1mol/L6The positive electrode, the negative electrode, the separation membrane and the electrolyte are assembled into a CR2032 button cell in a German Braun Lab type inert glove box (the content of water and oxygen is less than 1 ppm).
The graphene-lithium ion conductor material composite conductive paste obtained in example 6 was used to prepare a positive electrode sheet. The obtained positive electrode plate was subjected to scanning analysis using a Scanning Electron Microscope (SEM) of Coxem corporation or zeiss, and the result is shown in fig. 7. Fig. 7 is an SEM image of a positive electrode sheet prepared from the graphene-lithium ion conductor material composite conductive paste of example 6 of the present invention. In fig. 7, the spherical-like gray-white particle aggregates are the NCM523 positive electrode material, and the gray-black substance distributed between the NCM523 material samples or covering the NCM523 particles is the solid in the composite conductive paste of example 6. In the case ofIn the examples, the phosphate component is LiMn0.80Fe0.2PO4/C, the conductive component is a combination of graphene, carbon nanotubes and SP, and LiMn can be seen from FIG. 70.80Fe0.2PO4The uniform network layer structure is formed by the/C and the conductive component, and the network layer structure is uniformly and densely distributed on the surface of the spheroidal particles and among the particles of the positive electrode material, which explains that the introduction of the phosphate composite graphene conductive slurry provided by the invention improves the conductive performance of the electrode and the safety performance of the battery, because the network structure formed by the phosphate lithium ion conductor and the conductive carbon is a good conductor of lithium ions and electrons, and the phosphate has good thermal stability and can increase the safety of the battery.
The graphene-lithium ion conductor material composite conductive paste of the embodiment 8 is assembled into a CR2032 button cell according to the method of the embodiment 13, and the charge and discharge performance of the button cell is detected by a LAND cell tester (the test condition is room temperature). The results are shown in FIG. 8. Fig. 8 is a charge-discharge curve of a CR2032 button cell prepared from the graphene-lithium ion conductor material composite conductive pastes of example 8 and comparative example 4 of the present invention. Wherein, the curve of 523+ conductive paste in fig. 8 corresponds to the charge-discharge curve of the CR2032 button cell prepared from the graphene-lithium ion conductor material composite conductive paste in embodiment 8 of the present invention. Wherein the charge and discharge current density is 0.2C, 1C is calculated according to 170mAh/g, the active material does not contain the mass of the conductive carbon material when the specific capacity is calculated, the NCM523 positive electrode of the composite graphene conductive slurry is adopted, and the active material is the sum of the NCM523 and a phosphate component (LMFP 60 in the embodiment).
Comparative example 4
Assembling a CR2032 button cell:
the difference from example 13 is that: the anode material of the lithium ion battery (NCM523, Xiamen tungsten industry) and SP and polyvinylidene fluoride binder (Suwei 5130) are mixed according to the mass ratio of 92: 4: 4, mixing. And detecting the charge and discharge performance of the button cell by adopting a LAND cell tester. The results are shown in FIG. 8. Wherein, the curve of 523 in fig. 8 corresponds to the charge and discharge curve of the CR2032 button cell prepared in the comparative example 4 of the invention.
The specific discharge capacity of the CR2032 button cell prepared from the graphene-lithium ion conductor material composite conductive paste of example 8 of the invention is 165.7mAh/g (active material mass is calculated by NCM523 and composite conductive paste 96%), the specific discharge capacity of the CR2032 button cell prepared from comparative example 4 is 169mAh/g (active material mass is calculated by NCM523 and 92%), and the capacity exertion of the graphene-lithium ion conductor material composite conductive paste of example 8 is slightly lower than that of comparative example 4; comparative example the specific capacity of 161.9mAh/g, calculated as 96% active material, is less than 165.7mAh/g of the example. The LMFP60 composite graphene conductive paste is applied to the positive electrode of a lithium battery, and the electrode can keep higher capacity or energy density.
Example 14
Assembling a CR2032 button cell:
the only difference from example 13 is that: the anode material of the lithium ion battery adopts NCM622, and is in the Xiamen tungsten industry.
And (3) performance testing:
the graphene-lithium ion conductor material composite conductive pastes of comparative example 3, example 5 and example 8 were used to prepare 2032 type button cells according to the method of example 14. The ac impedance of the prepared 2032 type button cell was tested with the test equipment being the Autolab electrochemical workstation of the company wangton, switzerland under the test conditions of room temperature and the test frequency range of 1Hz to 10kHz, the results are shown in fig. 9. Fig. 9 is an ac impedance test chart of 2032 type button cell prepared from the graphene-lithium ion conductor material composite conductive pastes of comparative example 3, example 5 and example 8.
In fig. 9, the curves are from large to small in a semicircle, the curves correspond to the test results of comparative example 3, example 8 and example 5, respectively, and the horizontal axis of the curves corresponds to the resistances of about 102 ohms, 59 ohms and 38 ohms, respectively, which represents that the conductivity is comparative example 3 < example 8 < example 5, the LAGP in example 5 is a fast ion conductor of lithium, and the phosphate component is not contained in comparative example 3, which illustrates that the composite conductive paste of the present invention has the advantage of improving the conductivity.
Example 15
Assembling a CR2032 button cell:
the only difference from example 13 is that: the anode material of the lithium ion battery adopts NCM811, and is in the tungsten industry of Xiamen.
The test conditions are room temperature, the current used for constant current charging and discharging is 0.1C, the charging and discharging voltage is 4.3-2.5V, 5 times of cyclic charging and discharging are respectively carried out under the multiplying power of 0.2C, 0.5C, 1C and 2C, and the multiplying power performance of the button cell is tested, and is shown in figure 10. Fig. 10 is a discharge specific capacity curve diagram of the button cell battery of example 15 of the present invention at different rates. As can be seen from FIG. 10, the specific discharge capacity at 0.2C is about 203mAh/g, the specific discharge capacity after discharge at 0.5C is about 195mAh/g, the specific discharge capacity at 1C is about 180mAh/g, and the specific discharge capacity after discharge at 2C is about 167 mAh/g. Therefore, the rate capability is excellent.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. The graphene-lithium ion conductor material composite conductive slurry is prepared from raw materials comprising a component a, a component b and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component b comprises graphene.
2. The graphene-lithium ion conductor material composite conductive slurry is prepared from raw materials comprising a component a, a component c and an organic solvent;
the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
the component c is graphene composite slurry comprising a component b and a dispersant;
the component b comprises graphene.
3. The graphene composite conductive paste according to claim 1 or 2, wherein the component a accounts for 15-40% of the total mass of the raw materials, and the component b accounts for 2-4.5% of the total mass of the raw materials;
the lithium ion conductor material comprises LiMnPO4、LiMn0.75Fe0.25PO4、LiMn0.6Fe0.4PO4、Li3PO4、LiTi2(PO4)3And LiFePO4One or two of them;
in the carbon-coated lithium ion conductor material, the mass content of carbon is 1-3%;
the organic solvent comprises N-methyl pyrrolidone, dimethyl acetamide, N-dimethyl formamide or dimethyl sulfoxide.
4. The graphene composite conductive paste according to claim 1 or 2, wherein the component b comprises graphene and a conductive material;
the graphene is single-atom layer graphite or graphene nanosheets with 2-15 atomic layers;
the conductive material includes at least one of conductive graphite, conductive carbon black, acetylene black, SuperP-Li, carbon nanotubes, carbon nanofibers, and Ketjen black.
5. The graphene composite conductive paste according to claim 1, wherein the raw material further comprises a dispersant;
the dispersant accounts for 0.2 to 1 percent of the total mass of the raw materials;
the dispersing agent comprises one or two of polyvinylpyrrolidone, polyvinyl alcohol, Pluronic F127, Pluronic P123 and polyoxyethylene lauryl ether.
6. A preparation method of graphene-lithium ion conductor material composite conductive slurry comprises the following steps:
A1) grinding the component a until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B1) mixing the components obtained in the step A1) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising a component b and an organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene.
7. A preparation method of graphene-lithium ion conductor material composite conductive slurry comprises the following steps:
A2) grinding the component a and part of the organic solvent until the median particle size is 200-500 nm; the component a comprises a lithium ion conductor material and/or a carbon-coated lithium ion conductor material;
B2) mixing the components obtained in the step A2) with the conductive mixed slurry, and performing ultrasonic treatment or mechanical mixing to obtain graphene-lithium ion conductor material composite conductive slurry;
the conductive mixed slurry is prepared by mixing raw materials comprising the component b and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
or the conductive mixed slurry is prepared by mixing raw materials comprising the component c and the residual organic solvent and then carrying out ultrasonic treatment or mechanical mixing;
the component b comprises graphene;
the component c is graphene composite slurry comprising the component b and a dispersant.
8. The lithium ion battery positive plate is characterized in that the lithium ion battery positive plate is prepared by uniformly mixing raw materials including a positive material, composite conductive slurry and a binder and coating the mixture on a current collector;
the positive electrode material comprises one or two of lithium cobaltate, spinel lithium manganate, layered lithium nickel cobaltate, spinel lithium nickel manganate, a lithium-rich manganese-based material, layered lithium nickel manganese cobalt, a ternary material and lithium vanadate;
the composite conductive paste is the graphene-lithium ion conductor material composite conductive paste as defined in any one of claims 1 to 5 or the graphene-lithium ion conductor material composite conductive paste prepared by the preparation method as defined in any one of claims 6 to 7.
9. The positive plate of the lithium ion battery according to claim 8, wherein the composite conductive paste is contained in the raw material in an amount of 0.5 to 30% by mass.
10. A lithium ion battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, wherein the positive electrode comprises the positive electrode sheet of claim 8.
CN202110483733.5A 2021-04-30 2021-04-30 Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof Pending CN113193199A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110483733.5A CN113193199A (en) 2021-04-30 2021-04-30 Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110483733.5A CN113193199A (en) 2021-04-30 2021-04-30 Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN113193199A true CN113193199A (en) 2021-07-30

Family

ID=76983347

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110483733.5A Pending CN113193199A (en) 2021-04-30 2021-04-30 Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN113193199A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114142033A (en) * 2021-10-29 2022-03-04 合肥国轩高科动力能源有限公司 Modified graphite negative electrode material for lithium ion battery
CN114566393A (en) * 2022-03-23 2022-05-31 上海奥威科技开发有限公司 Composite positive electrode material for lithium ion capacitor and application thereof

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106450156A (en) * 2016-09-28 2017-02-22 湖南立方新能源科技有限责任公司 Electrode plate and manufacturing method thereof
CN109119699A (en) * 2018-08-30 2019-01-01 成都市银隆新能源产业技术研究有限公司 Low temperature improved lithium titanate battery and preparation method thereof
CN109417162A (en) * 2018-09-28 2019-03-01 宁波致良新能源有限公司 Anode additive and preparation method thereof, anode and preparation method thereof and lithium ion battery
CN109638202A (en) * 2018-11-22 2019-04-16 溧阳天目先导电池材料科技有限公司 A kind of ion-electron conductor composite membrane and preparation method thereof and lithium battery
CN109817871A (en) * 2019-03-29 2019-05-28 溧阳天目先导电池材料科技有限公司 A kind of ion conductor slurry and its preparation method and application
CN109888257A (en) * 2019-04-03 2019-06-14 山东星火科学技术研究院 A kind of graphene coated modification lithium-ion battery anode material and preparation method thereof
CN110415888A (en) * 2019-06-14 2019-11-05 江西力能新能源科技有限公司 A kind of carbon nanotube oil series conductive slurry and preparation method thereof containing solid electrolyte
CN111354925A (en) * 2018-12-21 2020-06-30 浙江伏打科技有限公司 Synthesis of carbon-bound lithium ion conductor-carbon composite negative electrode material with carbon fiber structure
CN112259707A (en) * 2020-10-21 2021-01-22 成都新柯力化工科技有限公司 Lithium battery negative pole piece loaded with temperature-resistant composite layer and preparation method thereof
CN112542572A (en) * 2019-09-23 2021-03-23 珠海冠宇电池股份有限公司 Novel lithium ion battery positive pole piece and preparation method and application thereof
CN113809331A (en) * 2020-06-17 2021-12-17 东营市海科新源化工有限责任公司 Multifunctional additive for lithium ion battery anode, preparation method of multifunctional additive and lithium ion battery

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106450156A (en) * 2016-09-28 2017-02-22 湖南立方新能源科技有限责任公司 Electrode plate and manufacturing method thereof
CN109119699A (en) * 2018-08-30 2019-01-01 成都市银隆新能源产业技术研究有限公司 Low temperature improved lithium titanate battery and preparation method thereof
CN109417162A (en) * 2018-09-28 2019-03-01 宁波致良新能源有限公司 Anode additive and preparation method thereof, anode and preparation method thereof and lithium ion battery
CN109638202A (en) * 2018-11-22 2019-04-16 溧阳天目先导电池材料科技有限公司 A kind of ion-electron conductor composite membrane and preparation method thereof and lithium battery
CN111354925A (en) * 2018-12-21 2020-06-30 浙江伏打科技有限公司 Synthesis of carbon-bound lithium ion conductor-carbon composite negative electrode material with carbon fiber structure
CN109817871A (en) * 2019-03-29 2019-05-28 溧阳天目先导电池材料科技有限公司 A kind of ion conductor slurry and its preparation method and application
CN109888257A (en) * 2019-04-03 2019-06-14 山东星火科学技术研究院 A kind of graphene coated modification lithium-ion battery anode material and preparation method thereof
CN110415888A (en) * 2019-06-14 2019-11-05 江西力能新能源科技有限公司 A kind of carbon nanotube oil series conductive slurry and preparation method thereof containing solid electrolyte
CN112542572A (en) * 2019-09-23 2021-03-23 珠海冠宇电池股份有限公司 Novel lithium ion battery positive pole piece and preparation method and application thereof
CN113809331A (en) * 2020-06-17 2021-12-17 东营市海科新源化工有限责任公司 Multifunctional additive for lithium ion battery anode, preparation method of multifunctional additive and lithium ion battery
CN112259707A (en) * 2020-10-21 2021-01-22 成都新柯力化工科技有限公司 Lithium battery negative pole piece loaded with temperature-resistant composite layer and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114142033A (en) * 2021-10-29 2022-03-04 合肥国轩高科动力能源有限公司 Modified graphite negative electrode material for lithium ion battery
CN114566393A (en) * 2022-03-23 2022-05-31 上海奥威科技开发有限公司 Composite positive electrode material for lithium ion capacitor and application thereof

Similar Documents

Publication Publication Date Title
CN109874306B (en) Cathode material, preparation method thereof, cathode and lithium ion battery
CN112447963B (en) Preparation method of lithium supplement conductive paste, lithium ion battery and electronic equipment
EP2760070A1 (en) Slurry composition for use in forming lithium-ion secondary battery electrode, containing cellulose fiber as binder, and lithium-ion secondary battery electrode
JP5839221B2 (en) Lithium secondary battery
Liu et al. Binder-free Si nanoparticles@ carbon nanofiber fabric as energy storage material
JP2013084397A (en) Lithium secondary battery manufacturing method
JP7337049B2 (en) Positive electrode composition for lithium ion secondary battery, positive electrode for lithium ion secondary battery, and lithium ion secondary battery
WO2013179924A1 (en) Electrode for lithium-ion secondary battery, and lithium-ion secondary battery using said electrode
EP3890062B1 (en) Lithium ion secondary battery positive electrode composition, lithium ion secondary battery positive electrode, and lithium ion secondary battery
CN111048760A (en) Positive electrode active material and method for producing same
Wang et al. A facile method of improving the high rate cycling performance of LiNi1/3Co1/3Mn1/3O2 cathode material
CN111653732A (en) Positive electrode material, positive electrode plate and lithium ion battery
TW201415697A (en) Electrode material for lithium ion secondary batteries, method for producing same, and lithium ion secondary battery
CN113193199A (en) Graphene-lithium ion conductor material composite conductive slurry, and preparation method and application thereof
Kebede et al. The electrical and electrochemical properties of graphene nanoplatelets modified 75V2O5–25P2O5 glass as a promising anode material for lithium ion battery
CN113401897B (en) Preparation method of black phosphorus-based graphite composite lithium ion battery negative electrode material
CN113594459B (en) Composite negative electrode material with multilayer structure and preparation method and application thereof
Qiao et al. Solvothermal preparation and lithium storage properties of Fe2O3/C hybrid microspheres
Bao et al. In-situ synthesis of FeF3/graphene composite for high-rate lithium secondary batteries
JP2015179608A (en) Negative electrode active material for lithium ion secondary batteries, manufacturing method thereof, and lithium ion secondary battery arranged by use thereof
JP2013161689A (en) Secondary battery electrode and manufacturing method of the same
JP2013084399A (en) Lithium ion secondary battery anode manufacturing method and lithium ion secondary battery manufacturing method
CN113161157B (en) Silicon-based composite anode active material, silicon-based composite anode, and preparation method and application thereof
JP2014235856A (en) Nonaqueous electrolyte secondary battery
JP7033258B2 (en) Positive electrode for non-aqueous electrolyte secondary batteries

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20210730