CN115626611A - Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof - Google Patents
Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof Download PDFInfo
- Publication number
- CN115626611A CN115626611A CN202211313520.9A CN202211313520A CN115626611A CN 115626611 A CN115626611 A CN 115626611A CN 202211313520 A CN202211313520 A CN 202211313520A CN 115626611 A CN115626611 A CN 115626611A
- Authority
- CN
- China
- Prior art keywords
- temperature
- carbon nitride
- stage
- mesoporous carbon
- washing
- 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
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 56
- 238000002360 preparation method Methods 0.000 title claims abstract description 45
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 44
- 239000010406 cathode material Substances 0.000 title claims abstract description 20
- 238000005406 washing Methods 0.000 claims abstract description 62
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 50
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 claims abstract description 47
- 239000002243 precursor Substances 0.000 claims abstract description 39
- 238000010438 heat treatment Methods 0.000 claims abstract description 38
- 238000001035 drying Methods 0.000 claims abstract description 36
- 239000002253 acid Substances 0.000 claims abstract description 32
- 238000002156 mixing Methods 0.000 claims abstract description 28
- 239000012043 crude product Substances 0.000 claims abstract description 27
- 238000004108 freeze drying Methods 0.000 claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000000843 powder Substances 0.000 claims abstract description 22
- 239000011148 porous material Substances 0.000 claims abstract description 19
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims abstract description 14
- -1 carbon nitride compound Chemical class 0.000 claims abstract description 10
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 60
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 33
- 239000004202 carbamide Substances 0.000 claims description 33
- 239000001103 potassium chloride Substances 0.000 claims description 30
- 235000011164 potassium chloride Nutrition 0.000 claims description 30
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 26
- 238000004321 preservation Methods 0.000 claims description 20
- 239000007773 negative electrode material Substances 0.000 claims description 19
- 238000007710 freezing Methods 0.000 claims description 18
- 230000008014 freezing Effects 0.000 claims description 18
- 238000002061 vacuum sublimation Methods 0.000 claims description 18
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 12
- 239000008367 deionised water Substances 0.000 claims description 11
- 229910021641 deionized water Inorganic materials 0.000 claims description 11
- 230000007935 neutral effect Effects 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 9
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical compound NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 claims description 7
- 238000003756 stirring Methods 0.000 claims description 7
- 229920000877 Melamine resin Polymers 0.000 claims description 6
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 6
- 239000011780 sodium chloride Substances 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- CKUAXEQHGKSLHN-UHFFFAOYSA-N [C].[N] Chemical compound [C].[N] CKUAXEQHGKSLHN-UHFFFAOYSA-N 0.000 claims description 3
- 229910017464 nitrogen compound Inorganic materials 0.000 claims description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 2
- 229910017604 nitric acid Inorganic materials 0.000 claims description 2
- 150000001805 chlorine compounds Chemical class 0.000 claims 1
- 239000002131 composite material Substances 0.000 claims 1
- 239000000243 solution Substances 0.000 description 29
- 230000000052 comparative effect Effects 0.000 description 22
- 238000012360 testing method Methods 0.000 description 10
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 7
- 229910052744 lithium Inorganic materials 0.000 description 7
- 241000512259 Ascophyllum nodosum Species 0.000 description 6
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 6
- KAESVJOAVNADME-UHFFFAOYSA-N Pyrrole Chemical compound C=1C=CNC=1 KAESVJOAVNADME-UHFFFAOYSA-N 0.000 description 6
- 238000001179 sorption measurement Methods 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 210000004027 cell Anatomy 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 239000007770 graphite material Substances 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 238000011056 performance test Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000013081 microcrystal Substances 0.000 description 3
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 3
- 238000009827 uniform distribution Methods 0.000 description 3
- 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
- 239000010405 anode material Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 238000005424 photoluminescence Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000012984 biological imaging Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000007600 charging Methods 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 238000010280 constant potential charging Methods 0.000 description 1
- 238000010277 constant-current charging Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 210000001787 dendrite Anatomy 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000000840 electrochemical analysis Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000007850 fluorescent dye Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000007146 photocatalysis Methods 0.000 description 1
- 230000001699 photocatalysis Effects 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
- C01B21/0605—Binary compounds of nitrogen with carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- 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
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/14—Pore volume
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/16—Pore diameter
- C01P2006/17—Pore diameter distribution
-
- 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 provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps: (1) Mixing a carbon nitride compound, a chloride and water, and fully dissolving to obtain a precursor solution; (2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; (3) Performing high-temperature treatment on the precursor powder obtained in the step (2) for at least 2 heating stages to obtain a carbon nitride crude product; (4) And (4) sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain the mesoporous carbon nitride. The average pore diameter of the mesoporous carbon nitride is 3-6nm. The mesoporous carbon nitride provided by the invention can be used as a cathode material of a lithium ion battery, can obviously improve the electrochemical performance of the battery, simplifies the process flow and reduces the preparation cost.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, relates to a negative electrode material, and particularly relates to mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof.
Background
Lithium ion batteries, which are products of the 20 th century and the 80 s, have been successfully applied in a large scale in various fields due to their rapid development in decades due to their advantages in performance and technology. According to the difference of the usage scenario and the energy size, the lithium ion battery can be specifically divided into a lithium power battery, a lithium consumer battery and a lithium energy storage battery. For each of the above lithium ion batteries, the negative electrode material is a crucial component in terms of energy density, service life, manufacturing cost, safety performance, and the like.
Early lithium ion batteries mainly used metallic lithium as a negative electrode material, but lithium dendrites inevitably appeared during multiple charge-discharge cycles, and the metallic lithium was easily punctured into a battery diaphragm to cause short circuit, thereby causing safety accidents. At present, the anode materials of large-scale commercial lithium ion batteries mainly comprise graphite carbon materials and lithium titanate, and other anode materials in the research stage mainly comprise transition metal oxides, silicon-based materials, other carbon materials and the like.
In recent years, graphite phase carbon nitride has been receiving wide attention from research and application because of its unique structure and excellent performance, and has been developing its potential value in the fields of energy, catalysis and sensing, and achieving important results in the fields of chemistry, materials, physics, biology, environment, energy and the like. Therefore, it is a diligent attempt by those skilled in the art to use it as a negative electrode material of a lithium ion battery.
CN 105152147A discloses a method for preparing water-soluble luminescent graphite phase carbon nitride nano kelp, which comprises the step of carrying out high-temperature polycondensation on nitrogen-containing and carbon-containing precursors in a mixed chloride molten salt system to obtain the water-soluble luminescent graphite phase carbon nitride nano kelp. The preparation method can obtain target products by adopting different types of precursors, and the prepared nano kelp is uniform in shape and good in dispersity in water, can form a high-concentration stable transparent colloidal solution, and can stably exist in alkaline and weakly acidic environments. Under the excitation of ultraviolet light, the nanometer kelp solid and the colloidal solution thereof have strong blue photoluminescence and stable luminescence. However, the nano kelp is only suitable for the fields of fluorescent probes, biological imaging, biomedical engineering, analysis and monitoring and the like due to good photoluminescence performance and water solubility of the nano kelp, and is not suitable for a negative electrode material of a lithium ion battery.
CN 112142023A discloses a preparation method of ionized carbon nitride, which specifically comprises the following steps: dissolving urea in water, adding a mixture of sodium chloride and potassium chloride to fully dissolve the urea, and obtaining ionized carbon nitride under the condition of quickly heating the solution; and dialyzing, filtering or centrifuging to obtain an ionized carbon nitride aqueous solution; drying to obtain the ionized carbon nitride powder. The ionized carbon nitride can be applied to the fields of photoelectrocatalysis, chemical sensing, photoelectric devices and the like due to excellent photocatalysis performance, but is not suitable for the cathode material of the lithium ion battery.
Therefore, how to provide the carbon nitride used as the lithium ion battery cathode material and the preparation method thereof can improve the electrochemical performance of the battery, simplify the process flow and reduce the preparation cost, and becomes a problem which needs to be solved urgently by technical personnel in the field at present.
Disclosure of Invention
The invention aims to provide mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preparing mesoporous carbon nitride used as a negative electrode material of a lithium ion battery, the method comprising the following steps:
(1) Mixing a carbon nitride compound, a chloride and water, and fully dissolving to obtain a precursor solution;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) for at least 2 heating stages to obtain a carbon nitride crude product;
(4) And (4) sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain the mesoporous carbon nitride.
The preparation method provided by the invention finally prepares the mesoporous carbon nitride suitable for the lithium ion battery cathode material by sequentially carrying out the processes of dissolution, freeze drying treatment, high-temperature treatment and post-treatment, and the whole preparation process is simple, the reaction is green and pollution-free, the operating conditions are easy to control, the preparation cost is reduced, and the economic benefit is improved.
In the invention, the freeze drying treatment promotes the full mixing of chloride as a template agent in the carbon nitride compound, thereby realizing the uniform distribution of the internal pore structure of the obtained carbon nitride; the high-temperature treatment is divided into at least 2 temperature rise stages, so that the full development of the pore structure is ensured, the collapse of the pore caused by too fast temperature rise is avoided, and the uniformity of pore distribution is further improved; the acid washes off chloride microcrystals doped in the carbon nitride crude product, and the purity of the mesoporous carbon nitride is further improved through subsequent water washing.
Compared with the common graphite material, the mesoporous carbon nitride obtained by the invention has larger specific surface area due to the porous structure, thereby providing more adsorption sites; meanwhile, the mesoporous carbon nitride has abundant defect pyridine N and pyrrole N empty sites, can provide additional Li adsorption sites, has stronger electronegativity, and can adsorb Li more easily, so that the electrochemical performance of the lithium ion battery when the mesoporous carbon nitride is used as a cathode material is remarkably improved.
Preferably, the carbon nitrogen compound in step (1) includes any one of urea, dicyandiamide or melamine or a combination of at least two of them, and typical but non-limiting combinations include a combination of urea and dicyandiamide, a combination of dicyandiamide and melamine, a combination of urea and melamine, or a combination of urea, dicyandiamide and melamine, and further preferably urea.
Preferably, the chloride of step (1) comprises potassium chloride and/or sodium chloride, and is further preferably potassium chloride.
Preferably, in the step (1), the mixing mass ratio of the carbon-nitrogen compound to the chloride is (5-15): 1, and may be, for example, 5.
In the invention, the mixing mass ratio of the carbon nitride compound and the chloride is crucial to the formation and distribution of the pore structure of the carbon nitride. When the mixing mass ratio is less than 5; when the mixing mass ratio is higher than 15.
Preferably, the dissolving process in step (1) is accompanied by stirring, and the stirring rate is 100-1000rpm, such as 100rpm, 200rpm, 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm or 1000rpm, but not limited to the recited values, and other unrecited values in the range of values are also applicable.
Preferably, the freeze-drying process of step (2) comprises low-temperature freezing and vacuum sublimation which are sequentially performed.
Preferably, the low temperature freezing temperature is from-10 to-50 ℃, and may be, for example, -10 ℃, -15 ℃, -20 ℃, -25 ℃, -30 ℃, -35 ℃, -40 ℃, -45 ℃ or-50 ℃, but is not limited to the recited values, and other values not recited in the range of values are equally applicable.
Preferably, the absolute pressure of the vacuum sublimation is 1 to 10Pa, and may be, for example, 1Pa, 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa or 10Pa, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the high-temperature treatment in step (3) includes 2 temperature-raising stages, namely a first temperature-raising stage and a second temperature-raising stage.
Preferably, the temperature rise rate of the first temperature rise stage is 4-6 ℃/min, and may be, for example, 4 ℃/min, 4.2 ℃/min, 4.4 ℃/min, 4.6 ℃/min, 4.8 ℃/min, 5 ℃/min, 5.2 ℃/min, 5.4 ℃/min, 5.6 ℃/min, 5.8 ℃/min, or 6 ℃/min, but is not limited to the recited values, and other values not recited within the range of values are also applicable.
Preferably, the target temperature of the first warming stage is 300-400 ℃, for example 300 ℃, 310 ℃, 320 ℃, 330 ℃, 340 ℃, 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃ or 400 ℃, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.
Preferably, the first temperature raising stage is maintained for a period of 2 to 4 hours, for example, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4 hours, but not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the temperature rise rate of the second temperature rise stage is 1-3 deg.C/min, and may be, for example, 1 deg.C/min, 1.2 deg.C/min, 1.4 deg.C/min, 1.6 deg.C/min, 1.8 deg.C/min, 2 deg.C/min, 2.2 deg.C/min, 2.4 deg.C/min, 2.6 deg.C/min, 2.8 deg.C/min, or 3 deg.C/min, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.
Preferably, the target temperature of the second temperature raising stage is 600-650 ℃, for example 600 ℃, 605 ℃, 610 ℃, 615 ℃, 620 ℃, 625 ℃, 630 ℃, 635 ℃, 640 ℃, 645 ℃ or 650 ℃, but is not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the holding time of the second temperature raising stage is 3 to 5 hours, for example, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, 4 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours or 5 hours, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the acid solution used in the acid washing in step (4) includes any one of a hydrochloric acid solution, a nitric acid solution or a sulfuric acid solution, and further preferably a hydrochloric acid solution.
Preferably, the acid solution used in the acid washing in step (4) has a concentration of 0.08-0.12mol/L, such as 0.08mol/L, 0.09mol/L, 0.1mol/L, 0.11mol/L or 0.12mol/L, but not limited to the recited values, and other values not recited in the range of the recited values are also applicable.
Preferably, the water washing in the step (4) is performed by using deionized water.
Preferably, the washing solution in the step (4) is neutral.
Preferably, the drying temperature in step (4) is 80-120 ℃, for example 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, but is not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the drying time in step (4) is 4-6h, for example 4h, 4.2h, 4.4h, 4.6h, 4.8h, 5h, 5.2h, 5.4h, 5.6h, 5.8h or 6h, but is not limited to the recited values, and other values not recited in this range are equally applicable.
As a preferred technical solution of the first aspect of the present invention, the preparation method comprises the steps of:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is (8-12) to 1, and stirring at the speed of 100-1000rpm until the urea and the potassium chloride are fully dissolved to obtain a precursor solution;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-10 to-50 ℃, and the absolute air pressure of the vacuum sublimation is 1-10Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 4-6 ℃/min, the target temperature is 300-400 ℃, and the heat preservation time is 2-4h; the temperature rise rate of the second temperature rise stage is 1-3 ℃/min, the target temperature is 600-650 ℃, and the heat preservation time is 3-5h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.08-0.12 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 80-120 ℃, and the drying time is 4-6h.
In a second aspect, the present invention provides a mesoporous carbon nitride for use as a negative electrode material in a lithium ion battery, obtained by the method according to the first aspect, wherein the mesoporous carbon nitride has an average pore size of 3 to 6nm, such as 3nm, 3.5nm, 4nm, 4.5nm, 5nm, 5.5nm or 6nm, but not limited to the recited values, and other values not recited in the recited values are also applicable.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the preparation method provided by the invention, the mesoporous carbon nitride suitable for the lithium ion battery cathode material is finally prepared by sequentially carrying out the processes of dissolving, freeze drying, high-temperature treatment and post-treatment, the whole preparation process is simple, the reaction is green and pollution-free, the operation condition is easy to control, the preparation cost is reduced, and the economic benefit is improved;
(2) The invention promotes the full mixing of chloride as a template agent in the carbon nitride through freeze drying treatment, thereby realizing the uniform distribution of the internal pore structure of the obtained carbon nitride; the high-temperature treatment is divided into at least 2 temperature rise stages, so that the full development of the pore structure is ensured, the collapse of the pore caused by too fast temperature rise is avoided, and the uniformity of pore distribution is further improved; chloride microcrystals doped in the carbon nitride crude product are washed away by the acid, and the purity of the mesoporous carbon nitride is further improved through subsequent washing;
(3) Compared with the common graphite material, the mesoporous carbon nitride obtained by the invention has larger specific surface area due to the porous structure, thereby providing more adsorption sites; meanwhile, the mesoporous carbon nitride has abundant defect pyridine N and pyrrole N empty sites, can provide additional Li adsorption sites, has stronger electronegativity, and can adsorb Li more easily, so that the electrochemical performance of the lithium ion battery when the mesoporous carbon nitride is used as a cathode material is remarkably improved.
Drawings
FIG. 1 is a graph showing the performance test of lithium ion batteries corresponding to the carbon nitrides obtained in example 1 and comparative examples 1 to 3;
fig. 2 is a graph showing the cycle performance of lithium ion batteries corresponding to the carbon nitrides obtained in example 1 and comparative examples 1 to 3.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitation of the present invention.
Example 1
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is 10;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze-drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-30 ℃, and the absolute air pressure of the vacuum sublimation is 5Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 5 ℃/min, the target temperature is 350 ℃, and the heat preservation time is 3h; the heating rate of the second heating stage is 2 ℃/min, the target temperature is 620 ℃, and the heat preservation time is 4h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.1 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 100 ℃, and the drying time is 5h.
Example 2
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is 8;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze-drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-20 ℃, and the absolute air pressure of the vacuum sublimation is 8Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 5 ℃/min, the target temperature is 350 ℃, and the heat preservation time is 3h; the heating rate of the second heating stage is 2 ℃/min, the target temperature is 620 ℃, and the heat preservation time is 4h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.09 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 90 ℃, and the drying time is 5h.
Example 3
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is 12;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-40 ℃, and the absolute air pressure of the vacuum sublimation is 3Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 5 ℃/min, the target temperature is 350 ℃, and the heat preservation time is 3h; the heating rate of the second heating stage is 2 ℃/min, the target temperature is 620 ℃, and the heat preservation time is 4h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.11 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 110 ℃ and the drying time is 5h.
Example 4
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is 5;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-10 ℃, and the absolute air pressure of the vacuum sublimation is 10Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 4 ℃/min, the target temperature is 300 ℃, and the heat preservation time is 4h; the heating rate of the second heating stage is 1 ℃/min, the target temperature is 600 ℃, and the heat preservation time is 5h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.08 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 80 ℃ and the drying time is 6h.
Example 5
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, wherein the preparation method comprises the following steps:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is 15;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze-drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-50 ℃, and the absolute air pressure of the vacuum sublimation is 1Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 6 ℃/min, the target temperature is 400 ℃, and the heat preservation time is 2h; the heating rate of the second heating stage is 3 ℃/min, the target temperature is 650 ℃, and the heat preservation time is 3h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.12 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 120 ℃, and the drying time is 4h.
Example 6
This embodiment provides a mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, in which the preparation method is the same as that of embodiment 1 except that urea in step (1) is changed to dicyandiamide, and thus, details are not described herein.
Example 7
This embodiment provides a mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, in which the preparation method is the same as that of embodiment 1 except that urea in step (1) is replaced by melamine, and thus, details are not described herein.
Example 8
The embodiment provides mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, wherein the preparation method is the same as that of embodiment 1 except that urea in step (1) is changed into urea and dicyandiamide which are mixed by equal mass, and thus the details are not repeated herein.
Example 9
This embodiment provides a mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, in which the preparation method is the same as that of embodiment 1 except that the potassium chloride in step (1) is changed to sodium chloride, and thus, details are not repeated herein.
Example 10
This embodiment provides a mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, in which except that the potassium chloride in step (1) is changed to equal mass of mixed potassium chloride and sodium chloride, the other steps and conditions are the same as those in embodiment 1, and thus are not described herein again.
Example 11
The embodiment provides mesoporous carbon nitride used as a lithium ion battery cathode material and a preparation method thereof, except that the mixing mass ratio in the step (1) is changed to 2.
Example 12
This embodiment provides a mesoporous carbon nitride used as a negative electrode material of a lithium ion battery and a preparation method thereof, in which except that the mixing mass ratio in step (1) is changed to 18.
Comparative example 1
The preparation method is the same as that of the embodiment 1 except that the high-temperature treatment in the step (3) is changed into 1 temperature rise stage, the temperature rise rate is 3 ℃/min, the target temperature is 620 ℃, the heat preservation time is 5h, and other steps and conditions are not repeated herein.
Comparative example 2
The present comparative example provides a carbon nitride for use as a negative electrode material of a lithium ion battery and a method for preparing the same, the method comprising the steps of:
(1) Mixing urea and potassium chloride according to a mass ratio of 10;
(2) Performing high-temperature treatment on the precursor powder obtained in the step (1) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 5 ℃/min, the target temperature is 350 ℃, and the heat preservation time is 3h; the heating rate of the second heating stage is 2 ℃/min, the target temperature is 620 ℃, and the heat preservation time is 4h;
(3) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (2) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.1 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 100 ℃, and the drying time is 5h.
Comparative example 3
The present comparative example provides a carbon nitride for use as a negative electrode material of a lithium ion battery and a method for preparing the same, the method comprising the steps of:
(1) Carrying out high-temperature treatment on urea to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 5 ℃/min, the target temperature is 350 ℃, and the heat preservation time is 3h; the heating rate of the second heating stage is 2 ℃/min, the target temperature is 620 ℃, and the heat preservation time is 4h;
(2) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (1) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.1 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 100 ℃, and the drying time is 5h.
The pore structure parameters of the carbon nitrides obtained in examples 1-12 and comparative examples 1-3 were determined as shown in Table 1 below.
TABLE 1
| Carbon nitride | Average pore diameter (nm) | Specific surface area (m) 2 /g) | Pore volume (cm) 3 /g) |
| Example 1 | 4.52 | 255 | 0.51 |
| Example 2 | 4.61 | 286 | 0.53 |
| Example 3 | 4.42 | 202 | 0.51 |
| Example 4 | 4.85 | 301 | 0.55 |
| Example 5 | 4.26 | 185 | 0.47 |
| Example 6 | 4.54 | 258 | 0.50 |
| Example 7 | 4.52 | 262 | 052 |
| Example 8 | 4.58 | 259 | 0.52 |
| Example 9 | 4.55 | 245 | 051 |
| Example 10 | 4.50 | 254 | 0.55 |
| Example 11 | 6.58 | 310 | 0.56 |
| Example 12 | 2.39 | 170 | 0.42 |
| Comparative example 1 | 5.67 | 210 | 0.57 |
| Comparative example 2 | 6.82 | 115 | 0.41 |
| Comparative example 3 | 1.27 | 95 | 0.23 |
As can be seen from Table 1: the proportion of urea and potassium chloride needs to be accurately controlled in a reasonable range, when the amount of potassium chloride is less, a mesoporous structure is not formed enough, and when the amount of potassium chloride is more, the aperture is easy to increase; the freeze drying of urea and potassium chloride can help to form mesoporous carbon nitride; the arrangement of the temperature gradient is also beneficial to generating mesoporous carbon nitride; some nitrocarbons can also be used as precursors to form carbon nitride, and both sodium chloride and potassium chloride can be used as salt templates.
The carbon nitride obtained in example 1 and comparative examples 1 to 3 was used as a negative electrode material to prepare a lithium ion battery, and the specific preparation method was: the 2032 type button cell is used for carrying out a full cell electrochemical test, and the full cell is assembled by taking ternary nickel cobalt lithium manganate (NCM 613) as a positive electrode material and mesoporous carbon nitride as a negative electrode material for carrying out the test. Fully stirring and mixing nickel cobalt lithium manganate, a binder PVDF and a conductive agent acetylene black in a proper amount of NMP solvent according to a mass ratio of 80; cutting and pressing the positive pole piece, weighing and marking, and drying in a vacuum drying oven at 90 ℃ for about 2h to obtain the positive pole piece; grinding mesoporous carbon nitride, and pressing to obtain a negative pole piece; the battery is installed under the condition that the oxygen content and the water content are both lower than 2.0ppm, and the battery is stood for more than 6 hours for being prepared for charge and discharge tests.
The lithium ion battery performance test curve corresponding to the carbon nitride obtained in example 1 and comparative examples 1 to 3 is shown in fig. 1, and the cycle performance curve is shown in fig. 2.
Wherein, the test conditions of the performance test curve are as follows: the charge and discharge mechanism of the battery test is constant current-constant voltage charge and constant current discharge. The cut-off voltage of constant current charging is 4.25V, and constant voltage charging is carried out until the cut-off current is 0.03C; the cut-off voltage of constant current discharge is 2.5V; the cell was activated for three cycles at 0.2C and 0.5C rates before testing.
The test conditions of the cycle performance curve are: the charge-discharge cycle test of the electrode material is carried out under the current density of 1C, and the multiplying power performance test is that the electrode material is cycled for 50 times under the multiplying power of 1C; the test temperature at room temperature was 25. + -. 3 ℃ and the test temperature at elevated temperature was 60 ℃.
As can be seen from fig. 1: the charging curves of example 1 and comparative examples 1 to 3 almost coincide, and the discharging curves are greatly different; the discharge capacity of example 1 can reach 166.7mAh/g, the discharge capacity of comparative example 1 is 159.8mAh/g, the discharge capacity of comparative example 2 is 157.6mAh/g, and the discharge capacity of comparative example 3 is 153.3mAh/g, which shows that the battery performance of example 1 is far superior to that of comparative examples 1-3.
As can be seen from fig. 2: after a 1C multiplying power cycle test is carried out on the assembled full battery, after 50 cycles, the capacity retention rate of the embodiment 1 is 99.09%, the capacity retention rate of the comparative example 1 is 96.54%, the capacity retention rate of the comparative example 2 is 92.32%, the capacity retention rate of the comparative example 3 is 79.47%, and the difference is obvious, so that the multiplying power cycle performance of the embodiment 1 is far superior to that of the comparative examples 1-3.
Therefore, the preparation method provided by the invention finally prepares the mesoporous carbon nitride suitable for the lithium ion battery cathode material by sequentially carrying out the processes of dissolution, freeze drying treatment, high-temperature treatment and post-treatment, and the whole preparation process is simple, the reaction is green and pollution-free, the operation conditions are easy to control, the preparation cost is reduced, and the economic benefit is improved.
Wherein, the freeze drying treatment promotes the full mixing of chloride as a template agent in the carbon nitride compound, thereby realizing the uniform distribution of the internal pore structure of the obtained carbon nitride; the high-temperature treatment is divided into at least 2 temperature rise stages, so that the full development of the pore structure is ensured, the collapse of the pore caused by too fast temperature rise is avoided, and the uniformity of pore distribution is further improved; the acid washes off chloride microcrystals doped in the carbon nitride crude product, and the purity of the mesoporous carbon nitride is further improved through subsequent water washing.
In addition, compared with the common graphite material, the mesoporous carbon nitride obtained by the invention has larger specific surface area due to the porous structure, thereby providing more adsorption sites; meanwhile, the mesoporous carbon nitride has abundant defect pyridine N and pyrrole N empty sites, can provide additional Li adsorption sites, has stronger electronegativity, and can adsorb Li more easily, so that the electrochemical performance of the lithium ion battery when the mesoporous carbon nitride is used as a cathode material is remarkably improved.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.
Claims (10)
1. A preparation method of mesoporous carbon nitride used as a lithium ion battery cathode material is characterized by comprising the following steps:
(1) Mixing a carbon nitride compound, a chloride and water, and fully dissolving to obtain a precursor solution;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) for at least 2 heating stages to obtain a carbon nitride crude product;
(4) And (4) sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain the mesoporous carbon nitride.
2. The method according to claim 1, wherein the carbon-nitrogen compound in step (1) comprises any one or a combination of at least two of urea, dicyandiamide, and melamine, and further preferably comprises urea;
preferably, the chloride in step (1) comprises potassium chloride and/or sodium chloride, and further preferably potassium chloride.
3. The production method according to claim 1 or 2, characterized in that the mixed mass ratio of the carbon nitride compound and the chloride compound in step (1) is (5-15): 1, and more preferably (8-12): 1;
preferably, the dissolving process in the step (1) is accompanied by stirring, and the stirring speed is 100-1000rpm.
4. The method according to any one of claims 1 to 3, wherein the freeze-drying treatment of step (2) comprises low-temperature freezing and vacuum sublimation which are carried out sequentially;
preferably, the temperature of the low-temperature freezing is-10 to-50 ℃;
preferably, the absolute pressure of the vacuum sublimation is 1-10Pa.
5. The production method according to any one of claims 1 to 4, wherein the high-temperature treatment of step (3) comprises 2 temperature-raising stages, a first temperature-raising stage and a second temperature-raising stage, respectively;
preferably, the heating rate of the first heating stage is 4-6 ℃/min;
preferably, the target temperature of the first temperature rise stage is 300-400 ℃;
preferably, the heat preservation time of the first temperature rise stage is 2-4h;
preferably, the temperature rise rate of the second temperature rise stage is 1-3 ℃/min;
preferably, the target temperature of the second temperature-raising stage is 600-650 ℃;
preferably, the holding time of the second temperature rise stage is 3-5h.
6. The method according to any one of claims 1 to 5, wherein the acid solution used in the acid washing in step (4) comprises any one of a hydrochloric acid solution, a nitric acid solution or a sulfuric acid solution, and is preferably a hydrochloric acid solution;
preferably, the acid solution concentration used in the acid washing in the step (4) is 0.08-0.12mol/L.
7. The production method according to any one of claims 1 to 6, wherein the water washing in step (4) is performed with deionized water;
preferably, the washing solution in the step (4) is neutral.
8. The method according to any one of claims 1 to 7, wherein the temperature for drying in step (4) is 80 to 120 ℃;
preferably, the drying time in step (4) is 4-6h.
9. The method for preparing a composite material according to any one of claims 1 to 8, comprising the steps of:
(1) Mixing urea, potassium chloride and water, wherein the mixing mass ratio of the urea to the potassium chloride is (8-12) to 1, and stirring at the speed of 100-1000rpm until the urea and the potassium chloride are fully dissolved to obtain a precursor solution;
(2) Performing freeze drying treatment on the precursor solution obtained in the step (1) to obtain precursor powder; the freeze drying treatment comprises low-temperature freezing and vacuum sublimation which are sequentially carried out, wherein the low-temperature freezing temperature is-10 to-50 ℃, and the absolute air pressure of the vacuum sublimation is 1-10Pa;
(3) Performing high-temperature treatment on the precursor powder obtained in the step (2) to obtain a carbon nitride crude product; the high-temperature treatment comprises 2 temperature-rising stages, namely a first temperature-rising stage and a second temperature-rising stage; the heating rate of the first heating stage is 4-6 ℃/min, the target temperature is 300-400 ℃, and the heat preservation time is 2-4h; the temperature rise rate of the second temperature rise stage is 1-3 ℃/min, the target temperature is 600-650 ℃, and the heat preservation time is 3-5h;
(4) Sequentially carrying out acid washing, water washing and drying on the carbon nitride crude product obtained in the step (3) to obtain mesoporous carbon nitride; the acid washing adopts hydrochloric acid solution with the concentration of 0.08-0.12 mol/L; the water washing is carried out by using deionized water until the washing liquid is neutral; the drying temperature is 80-120 ℃, and the drying time is 4-6h.
10. Mesoporous carbon nitride for use as a negative electrode material in a lithium ion battery, obtainable by a method according to any of claims 1 to 9, wherein the mesoporous carbon nitride has an average pore diameter of 3 to 6nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211313520.9A CN115626611A (en) | 2022-10-25 | 2022-10-25 | Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211313520.9A CN115626611A (en) | 2022-10-25 | 2022-10-25 | Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115626611A true CN115626611A (en) | 2023-01-20 |
Family
ID=84906526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211313520.9A Pending CN115626611A (en) | 2022-10-25 | 2022-10-25 | Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115626611A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104140084A (en) * | 2014-08-01 | 2014-11-12 | 中国人民解放军国防科学技术大学 | Method for preparing carbon nitride quantum dots |
| CN106276893A (en) * | 2016-07-18 | 2017-01-04 | 湘潭大学 | A kind of preparation method and applications of N doping Radix Puerariae base mesoporous activated carbon |
| CN110694660A (en) * | 2019-10-11 | 2020-01-17 | 力行氢能科技股份有限公司 | Heterogeneous element doped carbon nitride photocatalytic material and preparation method and application thereof |
| CN113540361A (en) * | 2021-06-23 | 2021-10-22 | 湖北大学 | Preparation method of doped material modified perovskite solar cell and product |
-
2022
- 2022-10-25 CN CN202211313520.9A patent/CN115626611A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104140084A (en) * | 2014-08-01 | 2014-11-12 | 中国人民解放军国防科学技术大学 | Method for preparing carbon nitride quantum dots |
| CN106276893A (en) * | 2016-07-18 | 2017-01-04 | 湘潭大学 | A kind of preparation method and applications of N doping Radix Puerariae base mesoporous activated carbon |
| CN110694660A (en) * | 2019-10-11 | 2020-01-17 | 力行氢能科技股份有限公司 | Heterogeneous element doped carbon nitride photocatalytic material and preparation method and application thereof |
| CN113540361A (en) * | 2021-06-23 | 2021-10-22 | 湖北大学 | Preparation method of doped material modified perovskite solar cell and product |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112151804B (en) | Prussian blue analogue-based carbon-coated transition metal oxide and preparation method and application thereof | |
| CN111244448B (en) | In-situ carbon-coated high-rate large-size Prussian blue type sodium ion positive electrode material and preparation method thereof | |
| CN107634220B (en) | Preparation method of prussian blue energy storage material | |
| CN108059144B (en) | Hard carbon prepared from biomass waste bagasse, and preparation method and application thereof | |
| CN104466168A (en) | Preparation method of cobaltosic oxide-carbon porous nanofiber and application of cobaltosic oxide-carbon porous nanofiber to preparation of lithium ion battery | |
| CN111943228A (en) | Prussian blue type sodium ion battery positive electrode material and preparation method thereof | |
| CN113054183A (en) | Preparation method of CoNi bimetal organic framework derived carbon-sulfur composite material | |
| CN111146424B (en) | Metal sulfide/carbon composite material, and preparation method and application thereof | |
| CN108565131B (en) | Method for preparing nitrogen-doped graphitized carbon | |
| CN111943225A (en) | Prussian blue type sodium ion battery positive electrode material and preparation method thereof | |
| CN108767203B (en) | Titanium dioxide nanotube-graphene-sulfur composite material and preparation method and application thereof | |
| CN111312999A (en) | Preparation method of graphene-coated nickel-iron bimetallic sulfide sodium-ion battery negative electrode material | |
| CN113793928A (en) | Modified ternary cathode material and preparation method and application thereof | |
| CN113036112A (en) | Preparation method of lithium-sulfur battery electrode material with nitrogen-rich porous carbon framework | |
| CN114300658A (en) | Doped coated sodium-ion battery positive electrode material and preparation method thereof | |
| CN113161533A (en) | MOF-derived ZnO @ C composite material and application thereof | |
| CN107978741B (en) | Preparation method of positive electrode composite material for lithium-sulfur battery | |
| CN107742710B (en) | Preparation method of chromium-based lithium ion battery composite negative electrode material | |
| CN114944480B (en) | Preparation method of honeycomb porous tin-carbon composite material | |
| CN107732206B (en) | Preparation method of bimetallic oxide composite negative electrode material with multilevel structure | |
| CN115172704A (en) | Preparation method for preparing porous carbon lithium iron phosphate cathode material by using metal organic framework | |
| CN113087014B (en) | Preparation method of carbon/selenium-doped titanium dioxide lithium-sulfur battery positive electrode material | |
| CN115626611A (en) | Mesoporous carbon nitride used as lithium ion battery cathode material and preparation method thereof | |
| CN115498183A (en) | Modified vanadium manganese sodium phosphate cathode material, preparation and application thereof | |
| CN112250119B (en) | Preparation method of nickel-manganese binary precursor with high electrochemical performance |
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 |