CN114628675A - Ternary lithium battery positive electrode material and preparation method thereof - Google Patents
Ternary lithium battery positive electrode material and preparation method thereof Download PDFInfo
- Publication number
- CN114628675A CN114628675A CN202111313768.0A CN202111313768A CN114628675A CN 114628675 A CN114628675 A CN 114628675A CN 202111313768 A CN202111313768 A CN 202111313768A CN 114628675 A CN114628675 A CN 114628675A
- Authority
- CN
- China
- Prior art keywords
- ternary
- composite carbon
- lithium
- lithium battery
- positive electrode
- 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.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
-
- 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
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention relates to the field of lithium ion battery anode materials, and discloses a ternary lithium battery anode material and a preparation method thereof, wherein the ternary lithium battery anode material comprises a ternary material and a coating agent coated on the surface of the ternary material, the coating agent comprises composite carbon, and the preparation method comprises the following steps: firstly, preparing COFs, and then sintering the COFs step by step to prepare composite carbon; calcining the ternary material precursor, the lithium source and the doping agent to prepare primary calcined powder, soaking the primary calcined powder and the composite carbon in a lithium hydroxide solution, and finally carrying out secondary calcination on the composite carbon soaked with the lithium hydroxide and the primary calcined powder to prepare a ternary cathode material; the composite carbon prepared by sintering COFs is coated on the ternary material, and the lithium ion transmission rate and the electronic conductivity of the ternary cathode material are obviously improved by soaking the composite carbon and the ternary material in lithium hydroxide, so that the side reaction between the ternary cathode material and electrolyte is effectively slowed down, and the battery capacity, the conductivity and the cycle life of the ternary material lithium battery are improved.
Description
Technical Field
The invention relates to the field of lithium ion battery anode materials, in particular to a ternary lithium battery anode material and a preparation method thereof.
Background
Lithium batteries are a research hotspot in the field of new energy, so the research on lithium battery electrodes is also concerned; the lithium battery electrode comprises a lithium battery anode and a lithium battery cathode, the development of the lithium battery cathode is relatively mature and stable, and the common cathode material is graphite; the positive electrode of the lithium battery has a complex structure and high development difficulty, and the current development direction mainly focuses on high capacity, long service life, low cost, safety, environmental protection and the like; the currently commonly used lithium battery anode material mainly comprises lithium cobaltate, a ternary material, lithium manganate and lithium iron phosphate, wherein the ternary material has the performances of high specific capacity, large energy density and large power density, and is considered as an anode material with development potential in the field, but the lithium battery anode material has lower electrochemical performance, thermal stability and structural stability in a high-temperature or high-potential test environment, and the problems are more prominent along with the improvement of nickel content, so that the ternary material needs to be modified during use; in the prior art, a ternary material is generally coated, and the structural stability, the thermal stability, the rate capability and the cycling stability of a ternary positive electrode are improved by utilizing a coating layer.
For example, publication No. CN111162249A discloses a positive electrode material for improving the first discharge capacity and a preparation method thereof, wherein the positive electrode material is made of a positive electrode material substrate, a lithium source and a coating agent, and the coating agent is one or more of boric acid, lithium borate, aluminum borate, sodium borate, potassium borate, aluminum oxide, titanium oxide, zirconium oxide and yttrium oxide.
For another example, publication No. CN202010442120.2 discloses a high voltage lithium cobaltate material, which is mainly prepared by reacting the following raw materials: a cobalt source, a lithium source, an additive, a coating agent A and a coating agent B; the coating agent A is at least one of nanoscale oxides, nanoscale hydroxides or nanoscale salts of Al, Ti, Co, Mg and Sn; the coating agent B is at least one of boric acid, lithium tetraborate, boron oxide, boron phosphate, titanium diboride or titanium metaborate; the mass ratio of the lithium source to the cobalt source is (1.03-1.07): 1.00.
in the prior art, a boron-containing material is usually used as a coating agent, but the lithium ion conductivity and the conductivity of the lithium battery can be reduced after the boron-containing material is used for coating a ternary material; therefore, it is required to provide a ternary lithium battery cathode material and a preparation method thereof to improve the performance of the lithium battery.
Disclosure of Invention
The invention aims to solve the problem that the conductivity and the conductivity of lithium ion of a lithium battery can be reduced when a ternary cathode material is coated and modified by using a coating agent in the prior art, and provides a ternary lithium battery cathode material and a preparation method thereof; meanwhile, the composite carbon coating layer can effectively slow down the side reaction between the ternary material and the electrolyte, thereby improving the cycle performance and prolonging the service life of the battery.
In order to achieve the purpose, the invention adopts the following technical scheme:
the ternary lithium battery positive electrode material comprises a ternary material and a coating agent coated on the surface of the ternary material, wherein the coating agent comprises composite carbon, and the composite carbon is prepared by sintering COFs.
According to the invention, the composite carbon obtained after the COFs are sintered is used as a coating agent, so that the conductivity and cycle performance of the ternary material are obviously improved; COFs are light materials composed of light elements such as C, H, N and F, and have the characteristics of high crystallinity, regular pore channel structures and large specific surface area, and meanwhile, the structural pore diameter can be designed manually, in the invention, cyclobutane tetracarboxylic dianhydride and 2, 6-diaminonaphthalene are used for synthesizing COFs, composite carbon with large specific surface area, multiple pores and high conductivity is formed by step-by-step calcination, the composite carbon formed by high-temperature ignition of the COFs in the invention has high carbon content, the composite carbon is prepared by dehydrating at low temperature, breaking oxygen bonds at medium temperature to enable the pore structures of the composite carbon to be more developed, and finally enabling the composite carbon to form a layered porous carbon skeleton at high temperature, after the composite carbon is coated on the surface of a ternary material, the surface area of a conductive network can be obviously improved, the electronic conductivity of the ternary material is obviously improved, lithium ions on the composite carbon can move in the pores of the composite carbon, the lithium ion de-intercalation path is shortened, the lithium ion transmission efficiency is obviously improved, and meanwhile, the composite carbon is wrapped on the surface of the ternary material, so that the side reaction between the ternary cathode material and the electrolyte can be effectively slowed down, the cycle performance of the ternary cathode material is improved, and the service life of the battery is prolonged.
Preferably, the mass ratio of the composite carbon accounts for 0.5-5% of the ternary cathode material.
Preferably, the preparation method of the composite carbon comprises the following steps:
(1) preparation of polyamide COFs: preparing N-methyl-2-pyrrolidone (NMP), mesitylene and isoquinoline into a solution according to the volume ratio of 0.5-1.5:0.5-1.0: 0.05-0.25; adding cyclobutanetetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the molar ratio of 1-2:0.5-1, uniformly mixing, heating, cooling to room temperature, filtering to obtain COFs, washing the COFs with an organic solvent, and performing vacuum drying; the reaction formula is as follows:
(2) preparing composite carbon: and (2) placing the prepared COFs into a ball mill for ball milling, screening after ball milling to prepare a composite carbon precursor, calcining the composite carbon precursor in an inert atmosphere, and performing calcination step by step, wherein the calcination step is to calcine the composite carbon precursor for 1h at 350 ℃ for 300-.
Preferably, the particle diameter of the composite carbon precursor is 2 to 2.5 μm.
Preferably, the heating temperature in the step (1) is 150-; the organic solvent in the step (1) is one or more selected from absolute ethyl alcohol, methanol and isopropanol.
Preferably, in the step (2), the ball milling temperature is 20-30 ℃, the ball milling frequency is 30-50HZ, the ball milling time is 5-15min, the ball milling interval is 1-2min, and the ball milling times are 3-6 ℃.
The invention also provides a preparation method of the ternary lithium battery anode material, which comprises the following steps:
a. preparing a composite carbon material;
b. uniformly mixing the precursor, a lithium source and a doping agent to obtain powder to be calcined, and then placing the powder to be calcined in an inert atmosphere for primary calcination to obtain primary calcined powder;
c. and uniformly dispersing the primary calcined powder and the composite carbon material in an alkaline solution, fully soaking, performing suction filtration and vacuum drying, and performing secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material.
The invention soaks the compound carbon and the ternary material in the lithium hydroxide alkaline solution and calcines, so that the lithium hydroxide crystals are attached to the inner part of the gaps of the compound carbon and the surface of the ternary material, the lithium ion exchange rate of the ternary anode material is obviously improved, the specific surface area of the compound carbon is large, pores are developed, a large amount of lithium hydroxide can be absorbed when lithium hydroxide is soaked, after firing, the lithium hydroxide is attached between the pores of the compound carbon in a crystalline state, after the ternary anode material is prepared by the ternary material wrapped by the compound carbon, a large amount of lithium exists on the surfaces of the wrapping agent and the ternary material, the lithium ion exchange rate can be obviously improved in the charging and discharging process, meanwhile, the lithium ions are consumed in the battery circulating process, the dead lithium in the anode and the cathode is increased, so that the battery circulating life is reduced, a large amount of active lithium is attached to the inner part of the compound carbon in the invention, and the lithium ion can be supplemented, improving the battery capacity and prolonging the cycle life of the battery.
Preferably, the molar ratio of the ternary material precursor to the lithium source in the step b is 1: 1.0-1.5; the doping agent is selected from one or more of zirconia, alumina, magnesia and strontium oxide, and the doping amount of the doping agent is 300-2000ppm of the mass of the precursor of the ternary material; the primary calcination temperature is 700-900 ℃, and the calcination time is 18-26 h.
Preferably, the alkali liquor in the step c is a lithium hydroxide solution, and the concentration of the alkali liquor is 0.1-5 mol/L; the stirring time in the step c is 0.5-5h, the vacuum drying temperature is 100 ℃ and 150 ℃, and the drying time is 10-24 h; the secondary calcination temperature is 700-900 ℃, and the calcination time is 2-6 h.
Therefore, the invention has the following beneficial effects:
(1) the composite carbon material obtained after the covalent organic material is sintered is used as a coating agent, so that the side reaction between the ternary cathode material and the electrolyte can be effectively slowed down, the cycle performance of the ternary cathode material is improved, and the service life of the battery is prolonged; the specific surface of the ternary material conductive network can be obviously increased, the electron transmission rate of the ternary material is increased, and the conductivity of the lithium battery is improved;
(2) the composite carbon is soaked in lithium hydroxide solution and then calcined, so that active lithium crystals are attached to the pores of the composite carbon, the exchange rate of lithium ions can be obviously improved, the conductive efficiency of the battery is improved, and the effects of supplementing lithium ions, improving the capacity of the battery and prolonging the cycle life of the battery can be achieved.
Detailed Description
The invention is further described with reference to specific embodiments.
In the present invention, all the raw materials are commercially available or commonly used in the industry, and the methods in the following examples are conventional in the art unless otherwise specified.
Example 1:
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) preparing NMP, mesitylene and isoquinoline into a solution according to a volume ratio of 0.5:0.5: 0.05; adding cyclobutanetetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the molar ratio of 1:0.5, uniformly mixing and heating at 150 ℃ for 60min, cooling to room temperature, filtering to obtain COFs, washing the COFs with absolute ethyl alcohol, and drying in vacuum at 70 ℃ for 10 h;
(2) placing the prepared COFs in a ball mill for ball milling processing, wherein the ball milling temperature is 20 ℃, the ball milling frequency is 30HZ, the ball milling time is 5min, the ball milling interval is 1min, the ball milling frequency is 3 times, screening is carried out after the ball milling processing to prepare a composite carbon precursor with the particle size of 2 micrometers, then calcining the composite carbon precursor in an inert atmosphere, and the calcining is carried out step by step, firstly calcining at 300 ℃ for 1h, then heating to 500 ℃ for continuous calcining for 2h, then heating to 700 ℃ for calcining for 1h, and cooling to prepare composite carbon;
(3) uniformly mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1), lithium carbonate and zirconia to obtain powder to be sintered, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1, and the doping amount of the zirconia is 300ppm of the mass of the NCM 811; placing the powder to be calcined in an argon atmosphere for primary calcination to prepare primary calcined powder, wherein the calcination temperature is 700 ℃, and the calcination time is 18 h;
(4) uniformly dispersing the primary calcined powder and the composite carbon material in 0.1mol/L lithium hydroxide solution, fully soaking, filtering, and drying in vacuum at 100 ℃ for 10 hours; and then carrying out secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material, wherein the calcination temperature is 700 ℃, and the calcination time is 2 hours.
Example 2:
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) preparing NMP, mesitylene and isoquinoline into a solution according to a volume ratio of 1:1: 0.15; adding tetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the molar ratio of 1.5:0.75, uniformly mixing and heating at 175 ℃ for 75min, cooling to room temperature, filtering to obtain COFs, washing the COFs with absolute ethyl alcohol, and drying in vacuum at 80 ℃ for 18 h;
(2) placing the prepared COFs in a ball mill for ball milling processing, wherein the ball milling temperature is 20-30 ℃, the ball milling frequency is 40HZ, the ball milling time is 10min, the ball milling interval is 1.5min, the ball milling frequency is 4 times, screening is carried out after the ball milling processing to obtain a composite carbon precursor with the particle size of 2.25 microns, placing the prepared COFs in the ball mill for ball milling processing, screening is carried out after the ball milling processing to obtain a composite carbon precursor, calcining the composite carbon precursor in an inert atmosphere, calcining step by step, firstly calcining at 325 ℃ for 1h, then heating to 550 ℃, continuing calcining for 2h, heating to 800 ℃ for 2h, and cooling to obtain composite carbon;
(3) uniformly mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1), lithium carbonate and zirconia to obtain powder to be sintered, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.25, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; placing the powder to be calcined in an argon atmosphere for primary calcination to prepare primary calcined powder, wherein the calcination temperature is 800 ℃, and the calcination time is 24 hours;
(4) uniformly dispersing the primary calcined powder and the composite carbon material in 2.5mol/L lithium hydroxide solution, fully soaking, carrying out suction filtration and vacuum drying, wherein the drying temperature is 125 ℃, and the drying time is 18 h; and then carrying out secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material, wherein the calcination temperature is 800 ℃, and the calcination time is 4 hours.
Example 3:
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) preparing NMP, mesitylene and isoquinoline into a solution according to a volume ratio of 1.5:1.0: 0.25; adding tetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the molar ratio of 2:1, uniformly mixing and heating at 200 ℃ for 90min, cooling to room temperature, filtering to obtain COFs, washing the COFs with absolute ethyl alcohol, and drying in vacuum at 90 ℃ for 24 h;
(2) placing the prepared COFs in a ball mill for ball milling processing, wherein the ball milling temperature is 30 ℃, the ball milling frequency is 50HZ, the ball milling time is 15min, the ball milling interval is 2min, the ball milling frequency is 6 times, screening is carried out after the ball milling processing to obtain a composite carbon precursor with the particle size of 2.5 microns, and then calcining the composite carbon precursor in an argon atmosphere to obtain a composite carbon material, wherein the calcining temperature is 500 ℃, the calcining time is 4 hours, and the heating rate is 5 ℃/min;
(3) uniformly mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1), lithium carbonate and zirconia to obtain powder to be sintered, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.5, and the doping amount of the zirconia is 2000ppm of the mass of the NCM 811; placing the powder to be calcined in an argon atmosphere for primary calcination to prepare primary calcined powder, wherein the calcination temperature is 900 ℃, and the calcination time is 26 hours;
(4) uniformly dispersing the primary calcined powder and the composite carbon material in 5mol/L lithium hydroxide solution, fully soaking, filtering, and drying in vacuum at 150 ℃ for 24 hours; and then carrying out secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material, wherein the calcination temperature is 900 ℃, and the calcination time is 6 hours.
Comparative example 1 (no NCM coating):
and calcining the powder material at 900 ℃ for 24h, and crushing to obtain the ternary cathode material. A preparation method of a ternary cathode material of a lithium ion battery comprises the following steps:
(1) mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1) with lithium carbonate and zirconia, and uniformly stirring to obtain a powder material, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.1, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; will be provided with
Comparative example 2 (coating with lithium hydroxide only):
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1) with lithium carbonate and zirconia, and uniformly stirring to obtain a powder material, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.1, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; carrying out primary calcination on the powder material at the calcination temperature of 800 ℃ for 24h, and crushing to obtain primary calcined sample powder;
(2) soaking the primary calcined sample powder in 2.5mol/L lithium hydroxide solution, filtering, vacuum drying after full soaking, drying at 125 ℃ for 18h, and then carrying out secondary calcination to obtain the ternary cathode material, wherein the calcination temperature is 900 ℃ and the calcination time is 24 h.
Comparative example 3 (coating with lithium borate only)
A preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1) with lithium carbonate and zirconia, and uniformly stirring to obtain a powder material, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.1, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; carrying out primary calcination on the powder material at the calcination temperature of 800 ℃ for 24h, and crushing to obtain primary calcined sample powder;
(2) and uniformly mixing the primary calcined sample powder with lithium borate, and then carrying out secondary calcination to obtain the ternary cathode material, wherein the mass of the lithium borate is 500ppm of the mass of the secondary calcined sample powder, the calcination temperature is 900 ℃, and the calcination time is 24 hours.
Comparative example 4 (composite carbon non-impregnated lithium hydroxide):
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) preparing NMP, mesitylene and isoquinoline into a solution according to a volume ratio of 1:1: 0.15; adding tetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the molar ratio of 1.5:0.75, uniformly mixing and heating at 175 ℃ for 75min, cooling to room temperature, filtering to obtain COFs, washing the COFs with absolute ethyl alcohol, and drying in vacuum at 80 ℃ for 18 h;
(2) placing the prepared COFs in a ball mill for ball milling processing, wherein the ball milling temperature is 25 ℃, the ball milling frequency is 40HZ, the ball milling time is 10min, the ball milling interval is 2min, the ball milling frequency is 5 times, screening is carried out after the ball milling processing to obtain a composite carbon precursor with the particle size of 2.25 microns, and then calcining the composite carbon precursor in an argon atmosphere to obtain a composite carbon material, wherein the calcining temperature is 400 ℃, the calcining time is 2.5h, and the heating rate is 3 ℃/min;
(3) uniformly mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1), lithium carbonate and zirconia to obtain powder to be sintered, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.25, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; placing the powder to be calcined in an argon atmosphere for primary calcination to prepare primary calcined powder, wherein the calcination temperature is 900 ℃, and the calcination time is 24 hours;
(4) uniformly dispersing the primary calcined powder in a 2.5mol/L lithium hydroxide solution, fully soaking, performing suction filtration and vacuum drying at the drying temperature of 125 ℃ for 18 h; and fully and uniformly mixing the dried primary calcined powder soaked with the lithium hydroxide and the composite carbon material to prepare secondary powder to be calcined, and then carrying out secondary calcination on the secondary powder to be calcined to prepare the ternary cathode material, wherein the calcination temperature is 900 ℃, and the calcination time is 4 hours.
Comparative example 5 (preparation of composite carbon using other COFs):
a preparation method of a ternary lithium battery positive electrode material comprises the following steps:
(1) preparing NMP, mesitylene and isoquinoline into a solution according to a volume ratio of 1:1: 0.15; then adding PMDA and TAPA into the dissolved solution according to the molar ratio of 1:0.5, uniformly mixing and heating at 175 ℃ for 75min, cooling to room temperature, filtering to obtain PMDA-TAPA-COFs, washing the PMDA-TAPA-COFs with absolute ethyl alcohol, and drying in vacuum at 80 ℃ for 18 h;
(2) placing the prepared PMDA-TAPA-COFs into a ball mill for ball milling processing, wherein the ball milling temperature is 25 ℃, the ball milling frequency is 40HZ, the ball milling time is 10min, the ball milling interval is 2min, the ball milling frequency is 4 times, screening is carried out after the ball milling processing to obtain a composite carbon precursor with the particle size of 2.25 mu m, and then calcining the composite carbon precursor in an argon atmosphere to obtain a composite carbon material, wherein the calcining temperature is 400 ℃, the calcining time is 2.5h, and the heating rate is 3 ℃/min;
(3) uniformly mixing an NCM ternary material precursor NCM811 (the molar ratio of Ni to Co to Mn is 8:1:1), lithium carbonate and zirconia to obtain powder to be sintered, wherein the molar ratio of the NCM811 to the lithium carbonate is 1:1.25, and the doping amount of the zirconia is 1000ppm of the mass of the NCM 811; then placing the powder to be calcined in an argon atmosphere for primary calcination to obtain primary calcined powder, wherein the calcination temperature is 900 ℃, and the calcination time is 24 hours;
(4) uniformly dispersing the primary calcined powder and the composite carbon material in 2.5mol/L lithium hydroxide solution, fully soaking, filtering, and drying in vacuum at 125 ℃ for 18 h; and then carrying out secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material, wherein the calcination temperature is 900 ℃, and the calcination time is 4 hours.
The ternary positive electrode materials obtained in the above examples and comparative examples were respectively assembled into soft-packed lithium batteries and subjected to performance tests, and the results are shown in table 1.
The positive electrode material in the soft package lithium ion battery comprises a ternary positive electrode material, a carbon black conductive agent, PVDF and a carbon nano tube in a mass ratio of 96:1.5:2:1, and the negative electrode material comprises artificial graphite, sodium carboxymethylcellulose (CMC), a synthetic rubber foam (SBR) and a carbon black conductive agent in a mass ratio of 95.5:1.5:2: 1;
the positive electrode material is added at 380g/m2Coating the surface density of the anode material on an aluminum foil with the thickness of 12 mu m, rolling, punching and baking to obtain an anode plate, and coating a cathode material 190 on the anode plateg/m2The surface density of the positive electrode is coated on a copper foil with the thickness of 6 mu m, a negative electrode pole piece is obtained after rolling, punching and baking, and the soft package lithium ion battery is prepared by adopting a lamination process and an aluminum plastic film packaging process.
And (3) testing conditions: testing voltage: 2.8-4.3V; capacity test conditions: and (5) 0.1C constant current charge and discharge test.
Table 1: and (5) testing the performance of the battery.
It can be seen from table 1 that the NCM ternary positive electrode materials obtained by using the coating agent and the preparation method of the present invention in examples 1-3 all have initial discharge capacities of 200mAh/g or more, cycle lives of 330 times or more, and 3C rate performance of 96% or more.
In comparative example 1, the ternary material is not subjected to coating modification, and the battery capacity, the cycle life and the rate performance are obviously lower than those of the ternary material in the invention from the result; the lithium hydroxide is used for coating and modifying the ternary material in the comparative example 2, but the battery capacity, the cycle life and the rate performance of the ternary material are still obviously lower than those of the lithium battery in the invention, and the lithium borate is used for modifying the ternary material in the comparative example 3, so that the battery performance of the ternary positive electrode material is still obviously lower than that of the lithium battery in the invention, which shows that the ternary positive electrode material prepared by the invention can obviously improve the battery capacity, the cycle life and the conductivity of the lithium battery.
In the comparative example 4, the cycle performance of the battery is obviously reduced compared with the embodiment by soaking the lithium hydroxide which is not soaked in the composite material, which shows that the cycle performance of the battery can be obviously improved and the service life of the battery can be prolonged after the composite carbon material is soaked; the composite carbon prepared by using the PMDA-TAPA-COFs in the comparative example 5 is used, but the test result shows that the cycle life of the lithium battery prepared by the composite carbon is obviously reduced compared with that of the lithium battery prepared by the embodiment, the reason is that the COFs used in the invention is different from the PMDA-TAPA-COFs used in the comparative example in high temperature resistance, when the composite carbon is prepared, the carbon content after high-temperature burning is 67%, the carbon content of the PMDA-TAPA-COFs is only 7%, and the calcining temperature during coating modification is higher, so that the composite carbon material with lower high temperature resistance is decomposed, and the coating modification is incomplete; the composite carbon has high structural porosity and large specific surface area, can contain a large amount of active lithium, can obviously improve the lithium ion exchange rate after being prepared into a ternary cathode material, and can supplement a large amount of lithium sources, thereby obviously improving the conductivity and the cycle life of the battery.
Data show that the coating agent and the preparation method can effectively improve the capacity performance, cycle life and rate capability of the battery.
Claims (9)
1. The ternary lithium battery positive electrode material is characterized by comprising a ternary material and a coating agent coated on the surface of the ternary material, wherein the coating agent comprises composite carbon, and the composite carbon is prepared by sintering COFs.
2. The ternary lithium battery positive electrode material as claimed in claim 1, wherein the composite carbon material accounts for 0.5-5% of the ternary positive electrode material by mass.
3. The positive electrode material for the ternary lithium battery as claimed in claim 1 or 2, wherein the preparation method of the composite carbon comprises the following steps:
(1) preparation of polyamide COFs: preparing N-methyl-2-pyrrolidone, mesitylene and isoquinoline into a solution according to the volume ratio of 0.5-1.5:0.5-1.0: 0.05-0.25; adding cyclobutanetetracarboxylic dianhydride and 2, 6-diaminonaphthalene into the solution according to the mass ratio of 1-2:0.5-1, uniformly mixing, heating, cooling to room temperature, filtering to obtain COFs, washing the COFs with an organic solvent, and performing vacuum drying;
(2) preparing composite carbon: and (2) placing the prepared COFs into a ball mill for ball milling, screening after ball milling to prepare a composite carbon precursor, calcining the composite carbon precursor in an inert atmosphere, and performing calcination step by step, wherein the calcination step is to calcine the composite carbon precursor for 1h at 350 ℃ for 300-.
4. The positive electrode material for a ternary lithium battery as claimed in claim 3, wherein the particle size of the composite carbon precursor is 2 to 2.5 μm.
5. The anode material for the ternary lithium battery as claimed in claim 3, wherein the heating temperature in the step (1) is 150-200 ℃, the heating time is 60-90min, the drying temperature is 70-90 ℃, and the drying time is 10-24 h; the organic solvent in the step (1) is one or more selected from absolute ethyl alcohol, methanol and isopropanol.
6. The positive electrode material for a ternary lithium battery as claimed in claim 3, wherein the ball milling temperature in step (2) is 20-30 ℃, the ball milling frequency is 30-50HZ, the ball milling time is 5-15min, the ball milling interval is 1-2min, and the ball milling frequency is 3-6 ℃.
7. A method for preparing a positive electrode material for a ternary lithium battery as claimed in any one of claims 1 to 6, comprising the steps of:
a. preparing a composite carbon material;
b. uniformly mixing the precursor, a lithium source and a doping agent to obtain powder to be calcined, and then placing the powder to be calcined in an inert atmosphere for primary calcination to obtain primary calcined powder;
c. and uniformly dispersing the primary calcined powder and the composite carbon material in an alkaline solution, fully soaking, performing suction filtration and vacuum drying, and performing secondary calcination to obtain the ternary cathode material with the surface coated with the composite carbon material.
8. The method for preparing the ternary lithium battery positive electrode material as claimed in claim 7, wherein the molar ratio of the ternary material precursor to the lithium source in the step b is 1: 1.0-1.5; the doping amount of the doping agent is 300-2000ppm of the mass of the precursor of the ternary material; the primary calcination temperature is 700-900 ℃, and the calcination time is 18-26 h.
9. The method as claimed in claim 7, wherein the alkali solution in step c is one or more selected from a group consisting of a lithium hydroxide solution, a lithium carbonate solution, and a lithium nitrate solution, and the concentration of the alkali solution is 0.1-5 mol/L; the stirring time in the step c is 0.5-5h, the vacuum drying temperature is 100 ℃ and 150 ℃, and the drying time is 10-24 h; the secondary calcination temperature is 700-900 ℃, and the calcination time is 2-6 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111313768.0A CN114628675B (en) | 2021-11-08 | 2021-11-08 | Ternary lithium battery anode material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111313768.0A CN114628675B (en) | 2021-11-08 | 2021-11-08 | Ternary lithium battery anode material and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114628675A true CN114628675A (en) | 2022-06-14 |
| CN114628675B CN114628675B (en) | 2023-08-15 |
Family
ID=81896596
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111313768.0A Active CN114628675B (en) | 2021-11-08 | 2021-11-08 | Ternary lithium battery anode material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114628675B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115064676A (en) * | 2022-06-29 | 2022-09-16 | 蜂巢能源科技股份有限公司 | Sodium-ion battery positive electrode material and preparation method and application thereof |
| CN115724420A (en) * | 2022-09-30 | 2023-03-03 | 重庆长安新能源汽车科技有限公司 | Bimetal doped porous carbon material, preparation method, application, coated positive electrode material and preparation method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105612441A (en) * | 2013-10-07 | 2016-05-25 | 三菱化学株式会社 | Polyimide composition, and alignment film and optical element formed using polyimide composition |
| CN109167042A (en) * | 2018-09-03 | 2019-01-08 | 桑德集团有限公司 | Lithium-rich manganese-based anode material of complex carbon material cladding and preparation method thereof, lithium battery |
| CN113363476A (en) * | 2021-03-24 | 2021-09-07 | 万向一二三股份公司 | Ternary cathode material of lithium ion battery and preparation method thereof |
| CN113363477A (en) * | 2021-03-26 | 2021-09-07 | 万向一二三股份公司 | Preparation method of multilayer coated ternary cathode material |
| CN113363475A (en) * | 2021-03-23 | 2021-09-07 | 万向一二三股份公司 | Preparation method of cobalt-free high-nickel magnesium-doped layered positive electrode material |
-
2021
- 2021-11-08 CN CN202111313768.0A patent/CN114628675B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105612441A (en) * | 2013-10-07 | 2016-05-25 | 三菱化学株式会社 | Polyimide composition, and alignment film and optical element formed using polyimide composition |
| CN109167042A (en) * | 2018-09-03 | 2019-01-08 | 桑德集团有限公司 | Lithium-rich manganese-based anode material of complex carbon material cladding and preparation method thereof, lithium battery |
| CN113363475A (en) * | 2021-03-23 | 2021-09-07 | 万向一二三股份公司 | Preparation method of cobalt-free high-nickel magnesium-doped layered positive electrode material |
| CN113363476A (en) * | 2021-03-24 | 2021-09-07 | 万向一二三股份公司 | Ternary cathode material of lithium ion battery and preparation method thereof |
| CN113363477A (en) * | 2021-03-26 | 2021-09-07 | 万向一二三股份公司 | Preparation method of multilayer coated ternary cathode material |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115064676A (en) * | 2022-06-29 | 2022-09-16 | 蜂巢能源科技股份有限公司 | Sodium-ion battery positive electrode material and preparation method and application thereof |
| CN115064676B (en) * | 2022-06-29 | 2023-11-03 | 蜂巢能源科技股份有限公司 | Sodium ion battery anode material and preparation method and application thereof |
| CN115724420A (en) * | 2022-09-30 | 2023-03-03 | 重庆长安新能源汽车科技有限公司 | Bimetal doped porous carbon material, preparation method, application, coated positive electrode material and preparation method |
| CN115724420B (en) * | 2022-09-30 | 2024-04-16 | 深蓝汽车科技有限公司 | Bimetal doped porous carbon material, preparation method, application and coated anode material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114628675B (en) | 2023-08-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108183224B (en) | In-situ nitrogen-doped porous core-shell structure carbon/selenium composite material and preparation method and application thereof | |
| CN109244546B (en) | Solid composite electrolyte film, preparation method thereof and all-solid-state battery | |
| CN107681147B (en) | Preparation method and application of solid electrolyte coated modified lithium ion battery positive electrode material | |
| CN112885985B (en) | Positive pole piece and preparation method thereof, electrochemical energy storage device and pre-metallization method of electrochemical energy storage device | |
| CN109461906B (en) | Preparation method of lithium-sulfur battery positive electrode material | |
| CN113363476B (en) | Ternary cathode material of lithium ion battery and preparation method thereof | |
| CN112599743B (en) | Carbon-coated nickel cobaltate multi-dimensional assembled microsphere negative electrode material and preparation method thereof | |
| CN112047399B (en) | Precursor with reticular structure, composite oxide powder, preparation method and application thereof | |
| CN114628675B (en) | Ternary lithium battery anode material and preparation method thereof | |
| CN114497527B (en) | Lithium-rich manganese-based positive electrode material, preparation method thereof and lithium ion battery | |
| CN113540466B (en) | Metal boride and borate composite coated modified nickel-cobalt-manganese ternary material precursor and preparation method thereof | |
| CN112281258A (en) | Li3VO4Negative electrode material of/C fiber lithium ion battery and preparation method | |
| CN111900407B (en) | Lithium-sulfur battery positive electrode material and preparation method thereof | |
| CN111244390B (en) | Metal oxide composite self-supporting heat-conducting carbon film, metal lithium cathode, and preparation and application thereof | |
| CN114937764A (en) | Cobalt disulfide composite material protected by double carbon layers and preparation method and application thereof | |
| CN109546099B (en) | Graphite composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN116588992B (en) | Borophosphate and pyrophosphate coated modified precursor and preparation method and application thereof | |
| CN114420883B (en) | Sodium ion battery anode material PTA large Kong Cengzhuang carbon rod and preparation method thereof | |
| CN114678501A (en) | Sodium manganate composite modified layered transition metal oxide positive electrode material and preparation method thereof | |
| CN110112376B (en) | Preparation method and application of porous silicon oxide/carbon composite negative electrode material | |
| CN116022859A (en) | Method for preparing positive electrode material and positive electrode material | |
| CN109461897B (en) | Preparation method of spindle-shaped carbon-coated vanadium-based positive electrode material | |
| CN109065879B (en) | Sodium-ion battery negative electrode material and preparation method thereof | |
| CN113072056A (en) | Preparation method of metal organic framework derived carbon with high specific surface area | |
| CN111162259A (en) | Preparation method of copper-coated porous silicon composite material and composite electrode for 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |