CN114156461A - Micron-sized coated polycrystalline cathode material and application thereof in lithium ion battery - Google Patents
Micron-sized coated polycrystalline cathode material and application thereof in lithium ion battery Download PDFInfo
- Publication number
- CN114156461A CN114156461A CN202110559259.XA CN202110559259A CN114156461A CN 114156461 A CN114156461 A CN 114156461A CN 202110559259 A CN202110559259 A CN 202110559259A CN 114156461 A CN114156461 A CN 114156461A
- Authority
- CN
- China
- Prior art keywords
- micron
- graphene
- sized
- positive electrode
- electrode 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
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 31
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 31
- 239000010406 cathode material Substances 0.000 title claims description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 143
- 229910021389 graphene Inorganic materials 0.000 claims abstract description 130
- 239000007774 positive electrode material Substances 0.000 claims abstract description 97
- 239000010405 anode material Substances 0.000 claims abstract description 30
- 239000006258 conductive agent Substances 0.000 claims abstract description 17
- 238000002360 preparation method Methods 0.000 claims abstract description 14
- 239000002994 raw material Substances 0.000 claims abstract description 11
- 239000011230 binding agent Substances 0.000 claims abstract description 9
- 239000002245 particle Substances 0.000 claims description 25
- 239000011248 coating agent Substances 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 15
- 238000009826 distribution Methods 0.000 claims description 12
- 238000001237 Raman spectrum Methods 0.000 claims description 10
- 238000003917 TEM image Methods 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 238000010586 diagram Methods 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 238000001878 scanning electron micrograph Methods 0.000 claims description 7
- 238000002441 X-ray diffraction Methods 0.000 claims description 6
- 229910002804 graphite Inorganic materials 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 6
- 229910032387 LiCoO2 Inorganic materials 0.000 claims description 3
- 229910013410 LiNixCoyAlzO2 Inorganic materials 0.000 claims description 3
- 229910013467 LiNixCoyMnzO2 Inorganic materials 0.000 claims description 3
- 239000002033 PVDF binder Substances 0.000 description 13
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 13
- 238000001035 drying Methods 0.000 description 11
- 239000011268 mixed slurry Substances 0.000 description 11
- 230000014759 maintenance of location Effects 0.000 description 10
- 239000003960 organic solvent Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 239000006229 carbon black Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 239000010410 layer Substances 0.000 description 4
- -1 polytetrafluoroethylene Polymers 0.000 description 4
- 238000001694 spray drying Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 229910004764 HSV900 Inorganic materials 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 239000011247 coating layer Substances 0.000 description 3
- 238000004146 energy storage Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 239000011232 storage material Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 2
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 description 2
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 229920001973 fluoroelastomer Polymers 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 241001521809 Acoma Species 0.000 description 1
- 229910001290 LiPF6 Inorganic materials 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000004108 freeze drying Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 238000001453 impedance spectrum Methods 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- 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
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- 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
- 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 related to lithium ion batteries, and particularly provides a lithium ion battery electrode made of a micron-sized coated polycrystalline positive electrode material, wherein the preparation raw materials comprise a micron-sized graphene coated polycrystalline positive electrode material, a conductive agent, a binder and a current collector; the preparation raw materials of the polycrystalline anode material coated by the micron-sized graphene comprise an anode material and graphene.
Description
Technical Field
The invention relates to the technical field related to lithium ion batteries, and particularly provides a micron-sized coated polycrystalline positive electrode material and application of the micron-sized coated polycrystalline positive electrode material to a lithium ion battery.
Background
With the development of the preparation technology of the lithium ion battery and the related materials thereof in recent years, the lithium ion battery undoubtedly replaces the nickel-hydrogen battery, the lead-acid battery and the like to become a new generation power supply with high technological content and the most extensive application, has the advantages of environmental protection, high energy density, good cycle performance, good safety performance and the like, is called as the most promising chemical power supply, and has become one of the most rapid and active areas of the global lithium ion battery in China. The positive electrode material of the lithium ion battery is one of the key factors determining the performance of the battery, and therefore, under the current situation, the development of the positive electrode material of the lithium ion battery with good thermal safety performance and cycle stability performance is urgent.
Graphene is used as a material with good conductivity, and is very suitable for being used as a coating material to carry out surface modification on a lithium ion positive electrode material. Therefore, a battery electrode material containing graphene uniformly coated with a positive electrode material is needed, and the service performance of the lithium ion battery is improved.
Disclosure of Invention
In order to solve the technical problems, a first aspect of the present invention provides a lithium ion battery electrode made of a micron-sized coated polycrystalline positive electrode material, wherein the preparation raw materials include a micron-sized graphene-coated polycrystalline positive electrode material, a conductive agent, a binder and a current collector; the preparation raw materials of the micron-sized graphene-coated polycrystalline positive electrode material comprise a positive electrode material and graphene.
As a preferable technical scheme of the invention, the average particle size of the graphene is 1-30 μm.
In a preferred embodiment of the present invention, the positive electrode material includes LiCoO2And/or LiNixCoyMnzO2And/or LiNixCoyAlzO2X + y + z is 1, x is more than or equal to 0.2 and less than or equal to 0.95, y is more than or equal to 0.05 and less than or equal to 0.4, and z is more than or equal to 0.05 and less than or equal to 0.5; the anode material is of a layered structure, belongs to an R-3m space group and is in a polycrystalline morphology.
As a preferable technical scheme of the invention, the weight ratio of carbon element to oxygen element in the graphene is (1-1000): 1.
as a preferable technical scheme of the invention, the number of layers of the graphene is 5-30.
As a preferred technical scheme of the invention, the graphene sheet diameter and D of the anode material50The ratio of the particle diameters is (0.01-2): 1.
as a preferred technical solution of the present invention, in an X-ray diffraction pattern, a pattern of the polycrystalline positive electrode material coated with the micron-sized graphene moves less than 3 ° compared to a pattern of the positive electrode material.
In a preferred embodiment of the present invention, in the particle size distribution diagram, the particle size distribution of the micron-sized graphene-coated polycrystalline positive electrode material is substantially the same as the particle size distribution of the positive electrode material.
As a preferred technical scheme of the present invention, in a laser raman spectrum, a D peak, a G peak, and a G 'peak of a coating region of the polycrystalline positive electrode material coated with the micron-sized graphene completely correspond to a D peak, a G peak, and a G' peak of the graphene, respectively.
As a preferred technical solution of the present invention, a TEM image of the micron-sized graphene-coated polycrystalline positive electrode material satisfies fig. 1; the SEM image satisfies that of FIG. 2; preferably, the included angle between the micron-sized graphene and the tangent line of the micron-sized graphene at the contact point of the cathode material is less than 5 degrees; the longest distance between the micron graphite and the surface of the anode material is less than 3 nm.
Compared with the prior art, the invention provides the lithium ion battery electrode made of the polycrystalline anode material coated by the micron-sized particles, the surface of the polycrystalline anode material is coated with the micron-sized graphene with a specific morphology, the graphene coated by the morphology does not change the original crystal phase structure and size of the polycrystalline anode material, the graphene coating layer prepared by the method is not easy to fall off, the charge transmission is facilitated, the conductivity of the material can be improved, and the prepared battery electrode has a certain improvement effect on the reduction of the alternating current impedance of the battery; the improvement effect on the retention rate of the circulating capacity at 45 ℃ is very obvious, the improvement effect on the retention rate of the high-rate charge-discharge capacity is certain, and the comprehensive performance of the battery can be optimized.
Drawings
FIG. 1: a TEM image of the micron graphene coated polycrystalline positive electrode material;
FIG. 2: an SEM image of the micron-sized graphene-coated polycrystalline positive electrode material at a magnification of 10 k;
FIG. 3: XRD patterns of a polycrystalline positive electrode material I coated by micron-sized graphene and a positive electrode material II;
FIG. 4: grain size distribution maps of a micron-sized graphene-coated polycrystalline positive electrode material I and a positive electrode material II;
FIG. 5: the Raman spectrum analysis method comprises the following steps of (a) carrying out Raman surface scanning on a polycrystalline cathode material coated by micron-sized graphene, (b) carrying out Raman spectrum analysis on a coating area and a non-coating area of the polycrystalline cathode material coated by the micron-sized graphene;
FIG. 6: electrochemical alternating-current impedance spectra of the batteries obtained in the example 1 and the comparative example 1;
FIG. 7: the cycle capacity retention ratio at 45 ℃ of the batteries obtained in the example 1 and the comparative example 1 is higher;
FIG. 8: the rate charge capacity retention ratio of the batteries obtained in the example 1 and the comparative example 1 is improved;
FIG. 9: the rate discharge capacity retention rate of the batteries obtained in the example 1 and the comparative example 1 is higher;
FIG. 10: a schematic structural diagram of a graphene-coated polycrystalline positive electrode material; wherein a is a schematic structural diagram of the graphene sheet-coated cathode material provided by the invention; b is a structural schematic diagram of the graphene sheet coated anode material in the traditional technology; 1. 3 represents a graphene sheet; 2. and 4 represents a positive electrode material.
Detailed Description
Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages herein are by weight and the testing and characterization methods used are synchronized with the filing date of the present application. To the extent that a definition of a particular term disclosed in the prior art is inconsistent with any definitions provided herein, the definition of the term provided herein controls.
The technical features of the technical solutions provided by the present invention are further clearly and completely described below with reference to the specific embodiments, and the scope of protection is not limited thereto.
The words "preferred", "preferably", "more preferred", and the like, in the present invention, refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention. The sources of components not mentioned in the present invention are all commercially available.
The invention provides a lithium ion battery electrode made of a micron-sized coated polycrystalline positive electrode material, which is prepared from the raw materials of the micron-sized coated polycrystalline positive electrode material, a conductive agent, a binder and a current collector; the preparation raw materials of the micron-sized graphene-coated polycrystalline positive electrode material comprise a positive electrode material and graphene.
In one embodiment, the particle size of the graphene is 1-30 μm; preferably, the graphene has an average particle size of 6 μm.
In one embodiment, the positive electrode material comprises LiCoO2And/or LiNixCoyMnzO2And/or LiNixCoyAlzO2X + y + z is 1, x is more than or equal to 0.2 and less than or equal to 0.95, y is more than or equal to 0.05 and less than or equal to 0.4, and z is more than or equal to 0.05 and less than or equal to 0.5; the anode material is of a layered structure, belongs to an R-3m space group and is in a polycrystalline morphology.
In a preferred embodiment, the positive electrode material is lithium nickel cobalt manganese oxide, and D50＝(12±1.0)μm。
In a more preferred embodiment, the lithium nickel cobalt manganese oxide is purchased from YHF-10F of yao graphene energy storage materials science and technology ltd, ningxia.
In one embodiment, the weight ratio of carbon element to oxygen element in the graphene is (1-1000): 1; preferably, the weight ratio of carbon element to oxygen element in the graphene is (200-800): 1; more preferably, the weight ratio of carbon element to oxygen element in the graphene is (400-600): 1; more preferably, the weight ratio of carbon element to oxygen element in the graphene is 500: 1.
in one embodiment, the number of graphene layers is 5 to 30; preferably, the number of layers of the graphene is about 13.
The applicant finds that the used micron-sized graphene has strong binding force when acting on a polycrystalline positive electrode material in an experimental process, the graphene coating layer prepared by the method is not easy to fall off, the propagation of charges is facilitated, the conductivity of the material can be improved, the prepared battery is facilitated to have smaller alternating current impedance, higher retention rate of 45 ℃ circulating capacity, higher retention rate of high-rate charging and discharging capacity, and the comprehensive performance of the battery is optimized.
In one embodiment, the graphene has a sheet diameter and a positive electrode material D50The ratio of the particle diameters is (0.01-2): 1; preferably, the graphene sheet diameter is equal to D of the cathode material50The ratio of the particle diameters is (0.08-1.8): 1; more preferably, the graphene sheet diameter is equal to D of the cathode material50The ratio of the particle diameters is (0.2 to 1): 1; more preferably, the graphene sheet diameter is equal to D of the cathode material50The ratio of the particle sizes is 0.5: 1.
in one embodiment, in an X-ray diffraction pattern, the pattern of the micron-sized graphene-coated polycrystalline positive electrode material has a pattern shift distance of less than 3 ° compared with the pattern of the positive electrode material; preferably, the pattern of the micron-sized graphene-coated polycrystalline cathode material is shifted by almost 0 ° compared to the pattern of the cathode material.
The "shift" refers to a shift of the pattern of the polycrystalline positive electrode material coated with graphene in the X-ray diffraction pattern to the left or right compared to the pattern of the positive electrode material.
In one embodiment, the micron-sized graphene coated polycrystalline positive electrode material has a particle size distribution substantially the same as a particle size distribution of the positive electrode material in the particle size distribution diagram.
The "substantially the same" means that the particle size distribution of the graphene-coated cathode material is little or unchanged from that of the cathode material, wherein the "little" means that the absolute value of the difference in the volume densities corresponding to the same particle size is less than 1%.
In one embodiment, in a laser raman spectrum, a D peak, a G peak, and a G 'peak of a coating region of the polycrystalline cathode material coated with the micron-sized graphene completely correspond to a D peak, a G peak, and a G' peak of graphene, respectively; the polycrystalline positive electrode material coated by the micron-sized graphene has no D peak, G peak and G' peak in a non-coating area; preferably, the laser Raman spectrum of the graphene has the Intensity (D)/Intensity (G) of 0.01-10, and the Intensity (D)/Intensity (D') -10 of 0.01-10; more preferably, the laser Raman spectrum of the graphene has the Intensity (D)/Intensity (G) of 0.01-5, and the Intensity (D)/Intensity (D') -5 of 0.01-5; more preferably, the laser Raman spectrum of the graphene has an Intensity (D)/Intensity (G) of 0.01-1, and an Intensity (D)/Intensity (D') -1 of 0.01-1.
In one embodiment, a TEM image of the micron-sized graphene coated polycrystalline positive electrode material satisfies fig. 1; the SEM image satisfies that of FIG. 2; preferably, the included angle between the micron-sized graphene and the tangent line of the micron-sized graphene at the contact point of the cathode material is less than 5 degrees; the longest distance between the micron graphite and the surface of the polycrystalline anode material is less than 3 nm; more preferably, the angle between the micron-sized graphene and the tangent thereof at the contact point of the positive electrode material is almost 0 °; the longest distance between the micron-sized graphite and the surface of the polycrystalline positive electrode material is almost 0 nm.
The TEM image of the micron-sized graphene-coated polycrystalline cathode material meets the requirement of the attached drawing 1; the SEM image satisfying fig. 2 "indicates that the TEM image and the SEM image of the polycrystalline cathode material coated with the micron-sized graphene are substantially the same as those of fig. 1 and 2, that is, the micron-sized graphene sheets shown in fig. 1 and 2 are in a close-fitting coating state on the surface of the polycrystalline cathode material grains.
As shown in fig. 10a, the micron-sized graphene can be well attached to the surface of the positive electrode material, the micron-sized graphene is tightly contacted with the positive electrode material without any gap, and the shortest distance between the micron-sized graphene and the surface of the positive electrode material is about 0; the graphene is obliquely positioned on the surface of the positive electrode material, the contact area or the coating area of the graphene on the surface of the positive electrode material is smaller under the condition of the same area of the graphene, a gap is formed between the graphene and the surface of the positive electrode material, the longest distance between the micron-sized graphite and the surface of the polycrystalline positive electrode material is far greater than 3nm, the close attachment shown in 10a is not achieved, and the range that the diameter of the micron-sized graphene sheet is in a coating state on the surface of the crystal grain of the polycrystalline positive electrode material is not included in the invention.
The applicant also finds that in the case that the micron-sized graphene sheets are in a tightly attached and coated state on the surface of the polycrystalline anode material crystal grains, the micron-sized graphene sheets, the polycrystalline anode material and the micron-sized graphene-coated polycrystalline anode material have great similarity in performance, that is, the error range of the result obtained by the same characterization means is small, and the method is also specifically described in the application.
In one embodiment, the binder comprises binder-1 and binder-2.
In one embodiment, the binder-1 is selected from one or more of fluororubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride and polytetrafluoroethylene-ethylene copolymer.
In a preferred embodiment, the binder-1 is polyvinylidene fluoride.
In a more preferred embodiment, the present invention does not particularly limit the manufacturer of the adhesive-1, which is available from HSV900 of Acoma corporation.
In one embodiment, the binder-2 is selected from one or more of fluororubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride and polytetrafluoroethylene-ethylene copolymer.
In a preferred embodiment, the binder-2 is polyvinylidene fluoride.
In a more preferred embodiment, the invention is not particularly limited by the manufacturer of binder-2, which is commercially available from Suwei as Battery grade PVDF 5130.
In one embodiment, the current collector is aluminum foil.
In one embodiment, the conductive agent is carbon black.
In a second aspect, the present invention provides a method for preparing a lithium ion battery electrode made of the micron-sized coated polycrystalline positive electrode material, including:
(1) uniformly mixing an organic solvent, graphene and a binder-1;
(2) mixing the substance obtained in the step (1), the positive electrode material and the organic solvent, and stirring for 2-4 hours at 30-60 ℃ to uniformly mix to obtain mixed slurry;
(3) drying the mixed slurry to obtain a micron-sized graphene-coated polycrystalline positive electrode material; preferably, the drying mode is any one selected from heating drying, spray drying, freeze drying, vacuum rotary drying, microwave drying, forced air drying and transmission drying; more preferably spray drying;
(4) and mixing the graphene-coated polycrystalline positive electrode material, the conductive agent and the binder-1, and coating the mixture on a current collector to prepare the positive electrode piece.
In one embodiment, the organic solvent is selected from any one or a combination of benzene, toluene, acetone, methyl ethyl ketone, N-methyl pyrrolidone (NMP), and dimethylformamide.
In a preferred embodiment, the organic solvent is NMP.
In one embodiment, the weight ratio of the graphene, the binder-1 and the positive electrode material is (0.01-0.05): (0.01-0.04): 1; preferably, the weight ratio of the graphene to the binder-1 to the positive electrode material is (0.02-0.03): (0.025-0.035): 1; more preferably, the weight ratio of the graphene, the binder-1 and the positive electrode material is 0.025: 0.03: 1.
in one embodiment, the viscosity of the mixed slurry is 280-900 cp; preferably, the viscosity of the mixed slurry is 500-700 cp; more preferably, the viscosity of the mixed slurry is 600 cp.
In one embodiment, the graphene-coated polycrystalline positive electrode material, the conductive agent and the binder-2 are in a weight ratio of (91-95): (1-4): (1-4); preferably, the weight ratio of the graphene-coated polycrystalline positive electrode material to the conductive agent to the binder-2 is (92-94): (2-3): (2-3); more preferably, the weight ratio of the graphene-coated polycrystalline positive electrode material to the conductive agent to the binder-2 is 93: 2: 2.
examples
In order to better understand the above technical solutions, the following detailed descriptions will be provided with reference to specific embodiments. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention. In addition, the starting materials used are all commercially available, unless otherwise specified.
Example 1
The embodiment 1 of the invention provides a lithium ion battery electrode made of a micron-sized coated polycrystalline positive electrode material, and the preparation raw materials comprise a micron-sized graphene coated polycrystalline positive electrode material, a conductive agent, a binder and a current collector; the preparation raw materials of the micron-sized graphene-coated polycrystalline positive electrode material comprise a positive electrode material and graphene.
The average particle size of the graphene is about 6 μm; the positive electrode material is nickel cobalt lithium manganate; the anode material is of a polycrystalline structure, belongs to an R-3m space group and is in a polycrystalline shape; the weight ratio of carbon element to oxygen element in the graphene is 500: 1; the number of layers of graphene is about 13.
D of graphene sheet diameter and anode material50The ratio of particle size is about 0.5: 1.
in an X-ray diffraction pattern, the pattern moving distance of the polycrystalline anode material coated by the micron-sized graphene is almost 0 degree compared with the pattern moving distance of the anode material; see fig. 3;
in the particle size distribution diagram, the particle size distribution of the micron-sized graphene-coated polycrystalline positive electrode material is basically the same as that of the positive electrode material, and is shown in fig. 4;
in a laser Raman spectrum, a D peak, a G peak and a G 'peak of a coating region of the micron-sized graphene coated polycrystalline positive electrode material completely correspond to the D peak, the G peak and the G' peak of graphene respectively; the micron-sized graphene-coated polycrystalline positive electrode material has no D peak, G peak and G' peak in a non-coating area; in the laser Raman spectrum of the graphene, the Intensity (D)/Intensity (G) is not less than 0.01 and not more than 1, and the Intensity (D)/Intensity (D') is not more than 0.01 and not more than 1, as shown in the attached figure 5;
according to TEM and SEM images of the polycrystalline anode material coated by the micron-sized graphene, the included angle between the micron-sized graphene and a tangent line of the micron-sized graphene at a contact point of the micron-sized graphene and the cathode material is almost 0 degree; the longest distance between the micron-sized graphite and the surface of the polycrystalline anode material is almost 0nm, and is shown in figures 1 and 2;
the binder comprises a binder-1 and a binder-2; the binder-1 is polyvinylidene fluoride; the binder-2 is polyvinylidene fluoride; the current collector is an aluminum foil, and the conductive agent is carbon black.
The graphene is purchased from GRCP0130L of Tianjin Ikewin graphene science and technology Limited; the positive electrode material is purchased from YHF-10F of Yao graphene energy storage materials science and technology Limited in Ningxia; the binder-1 was purchased from HSV900 of arkema; the binder-2 was purchased from Battery grade PVDF 5130 from Suwei; the aluminum foil is available from 1N00-H18 from five-star company; the carbon black is available from Cabot corporation as litx 200.
The preparation method of the lithium ion battery electrode made of the micron-sized coated polycrystalline positive electrode material comprises the following steps:
(1) uniformly mixing an organic solvent, graphene and a binder-1; the organic solvent is NMP;
(2) mixing the substance obtained in the step (1), the anode material and the organic solvent, and stirring for 3 hours at 45 ℃ to uniformly mix to obtain mixed slurry; the weight ratio of the graphene, the binder-1 and the positive electrode material is 0.025: 0.03: 1; the viscosity of the mixed slurry is 600 cp;
(3) drying the mixed slurry to obtain a micron-sized graphene-coated polycrystalline positive electrode material; the drying mode is spray drying;
(4) combining a graphene-coated polycrystalline positive electrode material, a conductive agent and a binder-2, and coating the mixture on a current collector to prepare a positive electrode plate; the weight ratio of the graphene coated polycrystalline positive electrode material to the conductive agent to the binder-2 is 93: 2: 2.
comparative example 1
The comparative example 1 of the invention provides a lithium ion battery electrode containing a polycrystalline positive electrode material, and the preparation raw materials comprise the polycrystalline positive electrode material, a conductive agent, a binder and a current collector.
The positive electrode material is nickel cobalt lithium manganate; the anode material is of a layered crystal polycrystalline structure, belongs to an R-3m space group and is in a polycrystalline appearance.
The binder comprises a binder-1 and a binder-2; the binder-1 is polyvinylidene fluoride; the binder-2 is polyvinylidene fluoride; the current collector is an aluminum foil; the conductive agent is carbon black.
The positive electrode material is purchased from YHF-10F of Yao graphene energy storage materials science and technology Limited in Ningxia; the binder-1 was purchased from HSV900 of arkema; the binder-2 was purchased from Battery grade PVDF 5130 from Suwei; the aluminum foil is available from 1N00-H18 from five-star company; the carbon black is available from Cabot corporation as litx 200.
The preparation method of the lithium ion battery electrode containing the polycrystalline anode material comprises the following steps:
(1) uniformly mixing an organic solvent and a binder-1; the organic solvent is NMP;
(2) mixing the substance obtained in the step (1), the anode material and the organic solvent, and stirring for 3 hours at 45 ℃ to uniformly mix to obtain mixed slurry; the weight ratio of the binder-1 to the positive electrode material is 0.03: 1; the viscosity of the mixed slurry is 600 cp;
(3) drying the mixed slurry to obtain a polycrystalline positive electrode material; the drying mode is spray drying;
(4) mixing a polycrystalline positive electrode material, a conductive agent and a binder-2, and coating the mixture on a current collector to prepare a positive electrode piece; the weight ratio of the polycrystalline positive electrode material to the conductive agent to the binder-2 is 93: 2: 2.
performance evaluation
The preparation method of the button cell comprises the following steps: and (3) drying the pole pieces prepared in the embodiment 1 and the comparative example 1 in a vacuum drying oven at 110 ℃ for 4-5 hours for later use. And rolling the pole piece on a rolling machine, and punching the rolled pole piece into a circular pole piece with a proper size. The cell assembly was carried out in a glove box filled with argon, the electrolyte of the electrolyte was 1M LiPF6, the solvent was EC: DEC: DMC 1: 1: 1 (volume ratio), and the metal lithium sheet is a counter electrode. The capacity test was performed on a blue CT model 2001A tester.
The cells obtained in example 1 and comparative example 1 were tested for electrochemical ac impedance at room temperature of 25 c, and the results are shown in fig. 6; performing charge-discharge cycle test at a high temperature of 45 ℃ at a charge-discharge rate of 0.5C/0.5C, respectively recording the last cycle discharge capacity and dividing by the 1 st cycle discharge capacity to obtain the cycle retention rate, wherein the experimental result is shown in FIG. 7; the battery rate charging performance is tested at the room temperature of 25 ℃, and the experimental result is shown in figure 8; the battery rate discharge performance was tested at room temperature at 25 ℃ and the results are shown in figure 9.
The data in the figure show that the surface of the polycrystalline anode material is coated with micron-sized graphene with a specific morphology, the morphology-coated graphene does not change the original crystal phase structure and size of the polycrystalline anode material, the graphene coating layer prepared by the method is not easy to fall off, charge transmission is facilitated, the conductivity of the material can be improved, and a certain improvement effect on reducing the alternating-current impedance of the prepared battery is achieved; the improvement effect on the retention rate of the circulating capacity at 45 ℃ is very obvious, and the circulating capacity can still be nearly 90% when the circulation is carried out for nearly 180 times; the method has certain improvement effect on the retention rate of high-rate charge-discharge capacity, and can optimize the comprehensive performance of the battery.
The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.
Claims (10)
1. A lithium ion battery electrode made of a micron-sized coated polycrystalline anode material is characterized in that the preparation raw materials comprise a micron-sized graphene coated polycrystalline anode material, a conductive agent, a binder and a current collector; the preparation raw materials of the micron-sized graphene-coated polycrystalline positive electrode material comprise a positive electrode material and graphene.
2. The lithium ion battery electrode of micron-sized coated polycrystalline positive electrode material of claim 1, wherein the graphene has an average particle size of 1-30 μm.
3. The lithium ion battery electrode of claim 1, wherein the micron-sized coated polycrystalline positive electrode material comprises LiCoO2And/or LiNixCoyMnzO2And/or LiNixCoyAlzO2X + y + z is 1, x is more than or equal to 0.2 and less than or equal to 0.95, y is more than or equal to 0.05 and less than or equal to 0.4, and z is more than or equal to 0.05 and less than or equal to 0.5; the anode material is of a layered structure, belongs to an R-3m space group and is in a polycrystalline morphology.
4. The lithium ion battery electrode made of the micron-sized coated polycrystalline cathode material according to claim 2, wherein the weight ratio of carbon element to oxygen element in the graphene is (1-1000): 1.
5. the lithium ion battery electrode made of the micron-sized coated polycrystalline positive electrode material according to claim 2, wherein the number of graphene layers is 5 to 30.
6. The micron-sized coated polycrystalline positive electrode material lithium ion battery electrode of claim 2, wherein the graphene sheet diameter is equal to D of the positive electrode material50The ratio of the particle diameters is (0.01-2): 1.
7. the lithium ion battery electrode of any one of claims 2 to 6, wherein the pattern of the micron-sized graphene coated polycrystalline positive electrode material is shifted by less than 3 ° compared with the pattern of the positive electrode material in an X-ray diffraction pattern.
8. The lithium ion battery electrode of any of claims 2 to 6, wherein the micron-sized graphene coated polycrystalline positive electrode material has a particle size distribution substantially the same as the positive electrode material in the particle size distribution diagram.
9. The lithium ion battery electrode made of the micron-sized coated polycrystalline cathode material according to any one of claims 2 to 6, wherein in a laser Raman spectrum, the D peak, the G peak and the G 'peak of the coating region of the micron-sized graphene coated polycrystalline cathode material completely correspond to the D peak, the G peak and the G' peak of graphene respectively.
10. The lithium ion battery electrode made of the micron-sized coated polycrystalline cathode material according to any one of claims 2 to 6, wherein a TEM image of the micron-sized graphene coated polycrystalline cathode material satisfies that shown in figure 1; the SEM image satisfies that of FIG. 2; preferably, the included angle between the micron-sized graphene and the tangent line of the micron-sized graphene at the contact point of the cathode material is less than 5 degrees; the longest distance between the micron graphite and the surface of the anode material is less than 3 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110559259.XA CN114156461A (en) | 2021-05-21 | 2021-05-21 | Micron-sized coated polycrystalline cathode material and application thereof in lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110559259.XA CN114156461A (en) | 2021-05-21 | 2021-05-21 | Micron-sized coated polycrystalline cathode material and application thereof in lithium ion battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114156461A true CN114156461A (en) | 2022-03-08 |
Family
ID=80460923
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110559259.XA Pending CN114156461A (en) | 2021-05-21 | 2021-05-21 | Micron-sized coated polycrystalline cathode material and application thereof in lithium ion battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114156461A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111640912A (en) * | 2020-05-13 | 2020-09-08 | 力神动力电池***有限公司 | Positive pole piece, preparation method thereof and lithium ion secondary battery |
| CN111969203A (en) * | 2020-07-29 | 2020-11-20 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing micro-nano graphene-coated single crystal cathode material |
| CN111969204A (en) * | 2020-07-29 | 2020-11-20 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing nano-grade graphene coated single crystal cathode material |
| CN112117460A (en) * | 2020-07-29 | 2020-12-22 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing micron-sized graphene-coated single crystal cathode material |
-
2021
- 2021-05-21 CN CN202110559259.XA patent/CN114156461A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111640912A (en) * | 2020-05-13 | 2020-09-08 | 力神动力电池***有限公司 | Positive pole piece, preparation method thereof and lithium ion secondary battery |
| CN111969203A (en) * | 2020-07-29 | 2020-11-20 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing micro-nano graphene-coated single crystal cathode material |
| CN111969204A (en) * | 2020-07-29 | 2020-11-20 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing nano-grade graphene coated single crystal cathode material |
| CN112117460A (en) * | 2020-07-29 | 2020-12-22 | 宁夏汉尧石墨烯储能材料科技有限公司 | Lithium ion battery electrode containing micron-sized graphene-coated single crystal cathode material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bie et al. | Li 2 O 2 as a cathode additive for the initial anode irreversibility compensation in lithium-ion batteries | |
| Zhao et al. | Structural and electrochemical characteristics of Li4− xAlxTi5O12 as anode material for lithium-ion batteries | |
| CN112117460B (en) | Lithium ion battery electrode containing micron-sized graphene-coated single crystal cathode material | |
| Wu et al. | Effect of TiO2-coating on the electrochemical performances of LiCo1/3Ni1/3Mn1/3O2 | |
| EP3506402B1 (en) | Carbon black for batteries, conductive composition for electrodes, electrode for batteries, and battery | |
| CN111969203B (en) | Lithium ion battery electrode containing micro-nano graphene-coated single crystal cathode material | |
| CN111969204B (en) | Lithium ion battery electrode containing nano-grade graphene coated single crystal cathode material | |
| Liu et al. | Fluorine doping and Al2O3 coating Co-modified Li [Li0. 20Ni0. 133Co0. 133Mn0. 534] O2 as high performance cathode material for lithium-ion batteries | |
| Lei et al. | Effects of particle size on the electrochemical properties of aluminum powders as anode materials for lithium ion batteries | |
| CN108417813A (en) | A kind of preparation method of lithium ion battery negative material | |
| KR101122715B1 (en) | Method for preparing cathode materials for lithum ion secondary Battery | |
| CN111193018B (en) | Lithium battery positive active material and preparation method and application thereof | |
| Zhou et al. | Synthesis and electrochemical properties of LiAl0. 05Mn1. 95O4 by the ultrasonic assisted rheological phase method | |
| Jiao et al. | An advanced lithium ion battery based on a high quality graphitic graphene anode and a Li [Ni0. 6Co0. 2Mn0. 2] O2 cathode | |
| CN110098387B (en) | Lithium phosphate and conductive carbon material coated ternary cathode material and preparation method and application thereof | |
| CN112002896B (en) | Preparation method of lithium ion battery electrode containing graphene-coated single crystal positive electrode material | |
| CN110783564A (en) | Nitrogen-doped carbon-coated ternary positive electrode material and preparation method thereof | |
| CN115295789A (en) | Positive active material and application thereof | |
| Watanabe et al. | Prevention of the micro cracks generation in LiNiCoAlO2 cathode by the restriction of ΔDOD | |
| Zhang et al. | Activated nanolithia as an effective prelithiation additive for lithium-ion batteries | |
| Yang et al. | Enhanced overcharge behavior and thermal stability of commercial LiCoO2 by coating with a novel material | |
| CN113161532A (en) | Negative electrode active material, and negative electrode, secondary battery, and electronic device including same | |
| CN114843472B (en) | Cobalt-free layered cathode material and preparation method and application thereof | |
| CN116190552A (en) | Li (lithium ion battery) 2 B 4 O 7 Preparation method of LiF co-coated high-nickel NCM lithium ion battery anode material | |
| CN114142023A (en) | Coated mono-like anode material and application of coated mono-like anode material to lithium ion battery |
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 |