CN114180565A - Three-dimensional porous graphite material and preparation method and application thereof - Google Patents
Three-dimensional porous graphite material and preparation method and application thereof Download PDFInfo
- Publication number
- CN114180565A CN114180565A CN202111376551.4A CN202111376551A CN114180565A CN 114180565 A CN114180565 A CN 114180565A CN 202111376551 A CN202111376551 A CN 202111376551A CN 114180565 A CN114180565 A CN 114180565A
- Authority
- CN
- China
- Prior art keywords
- solvent
- gel
- carbon
- graphite material
- containing polymer
- 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
- 239000007770 graphite material Substances 0.000 title claims abstract description 51
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 239000002904 solvent Substances 0.000 claims abstract description 46
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000004108 freeze drying Methods 0.000 claims abstract description 22
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 21
- 229920000642 polymer Polymers 0.000 claims abstract description 21
- 238000007710 freezing Methods 0.000 claims abstract description 16
- 230000008014 freezing Effects 0.000 claims abstract description 16
- 238000010000 carbonizing Methods 0.000 claims abstract description 9
- 239000000126 substance Substances 0.000 claims abstract description 6
- 239000000243 solution Substances 0.000 claims description 29
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 claims description 27
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 15
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims description 14
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 13
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 12
- 238000002791 soaking Methods 0.000 claims description 11
- 239000011148 porous material Substances 0.000 claims description 10
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 239000007773 negative electrode material Substances 0.000 claims description 8
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 claims description 7
- 229910001414 potassium ion Inorganic materials 0.000 claims description 7
- 235000005074 zinc chloride Nutrition 0.000 claims description 7
- 239000011592 zinc chloride Substances 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 claims description 6
- 229960000583 acetic acid Drugs 0.000 claims description 5
- 150000007522 mineralic acids Chemical class 0.000 claims description 5
- 239000005011 phenolic resin Substances 0.000 claims description 5
- 229920002401 polyacrylamide Polymers 0.000 claims description 5
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 claims description 5
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 4
- 229910017053 inorganic salt Inorganic materials 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 229910017604 nitric acid Inorganic materials 0.000 claims description 4
- 229920001568 phenolic resin Polymers 0.000 claims description 4
- ZMZDMBWJUHKJPS-UHFFFAOYSA-M Thiocyanate anion Chemical compound [S-]C#N ZMZDMBWJUHKJPS-UHFFFAOYSA-M 0.000 claims description 3
- UQXKXGWGFRWILX-UHFFFAOYSA-N ethylene glycol dinitrate Chemical compound O=N(=O)OCCON(=O)=O UQXKXGWGFRWILX-UHFFFAOYSA-N 0.000 claims description 3
- ZMZDMBWJUHKJPS-UHFFFAOYSA-N hydrogen thiocyanate Natural products SC#N ZMZDMBWJUHKJPS-UHFFFAOYSA-N 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- VLTRZXGMWDSKGL-UHFFFAOYSA-M perchlorate Inorganic materials [O-]Cl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-M 0.000 claims description 3
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims description 3
- 238000003763 carbonization Methods 0.000 claims description 2
- 239000012362 glacial acetic acid Substances 0.000 claims description 2
- 238000005087 graphitization Methods 0.000 abstract description 7
- 239000000047 product Substances 0.000 description 23
- 239000007795 chemical reaction product Substances 0.000 description 13
- 238000003756 stirring Methods 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- 239000010439 graphite Substances 0.000 description 8
- 239000013067 intermediate product Substances 0.000 description 8
- 229910052744 lithium Inorganic materials 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 8
- 229920003987 resole Polymers 0.000 description 8
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- 229910002804 graphite Inorganic materials 0.000 description 7
- 238000001291 vacuum drying Methods 0.000 description 7
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 6
- 239000008367 deionised water Substances 0.000 description 6
- 229910021641 deionized water Inorganic materials 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229960001760 dimethyl sulfoxide Drugs 0.000 description 5
- 238000007599 discharging Methods 0.000 description 5
- 239000003792 electrolyte Substances 0.000 description 5
- NBZBKCUXIYYUSX-UHFFFAOYSA-N iminodiacetic acid Chemical compound OC(=O)CNCC(O)=O NBZBKCUXIYYUSX-UHFFFAOYSA-N 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 229910052700 potassium Inorganic materials 0.000 description 5
- 239000011591 potassium Substances 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 4
- 239000007806 chemical reaction intermediate Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910001416 lithium ion Inorganic materials 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
- VGTPCRGMBIAPIM-UHFFFAOYSA-M sodium thiocyanate Chemical compound [Na+].[S-]C#N VGTPCRGMBIAPIM-UHFFFAOYSA-M 0.000 description 4
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 3
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 238000007605 air drying Methods 0.000 description 3
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- 238000001069 Raman spectroscopy Methods 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 230000001351 cycling effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- ZIUHHBKFKCYYJD-UHFFFAOYSA-N n,n'-methylenebisacrylamide Chemical compound C=CC(=O)NCNC(=O)C=C ZIUHHBKFKCYYJD-UHFFFAOYSA-N 0.000 description 2
- 239000003495 polar organic solvent Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- KWYHDKDOAIKMQN-UHFFFAOYSA-N N,N,N',N'-tetramethylethylenediamine Chemical compound CN(C)CCN(C)C KWYHDKDOAIKMQN-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- HQCVEGNPQFRFPC-UHFFFAOYSA-N carboxy acetate Chemical compound CC(=O)OC(O)=O HQCVEGNPQFRFPC-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000004312 hexamethylene tetramine Substances 0.000 description 1
- 235000010299 hexamethylene tetramine Nutrition 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- DCYOBGZUOMKFPA-UHFFFAOYSA-N iron(2+);iron(3+);octadecacyanide Chemical compound [Fe+2].[Fe+2].[Fe+2].[Fe+3].[Fe+3].[Fe+3].[Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] DCYOBGZUOMKFPA-UHFFFAOYSA-N 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 229960003351 prussian blue Drugs 0.000 description 1
- 239000013225 prussian blue Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 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
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- 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
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
Abstract
The invention relates to a three-dimensional porous graphite material and a preparation method and application thereof, wherein the preparation method comprises the following steps: 1) freeze drying the gel of the carbon-containing polymer; 2) carbonizing the dried substance in the step 1) at 2000-3000 ℃. Wherein, the gel of the carbon-containing polymer in the step 1) contains a solvent A, and the freezing point of the solvent A is higher than the freeze drying temperature. The three-dimensional porous graphite material prepared by the invention has the characteristics of multiple active sites, high graphitization degree and hierarchical porosity, and can effectively improve the rate capability and cycle performance of a battery.
Description
Technical Field
The invention belongs to the technical field of graphite materials, and particularly relates to a three-dimensional porous graphite material and a preparation method and application thereof.
Background
The lithium ion battery has the advantages of high voltage, large energy density, stable circulation and the like, so that the lithium ion battery becomes an energy storage device of most electronic products and energy power equipment. However, the content of lithium metal in the earth crust is about 0.0065%, 70% of lithium in the world is in south America, China has some lithium resources, but the rapid development of the society makes the annual lithium demand in China huge, and a large amount of lithium is imported from foreign countries every year. The scarce lithium resource is extremely unfavorable for future traffic development and social construction, and researchers aim at the potassium element in the same main group with lithium in order to solve the problem of insufficient lithium resource.
The graphite used as the negative electrode material of the potassium ion battery has low price and mature production process, but the graphite still faces some problems when being used as the negative electrode material of the potassium ion battery: e.g. K+Size ratio of (A) to (B) Li+Has a much larger size, the graphite has larger volume change during the charge-discharge cycle, especially the graphite forms KC8The volume expansion of the back material is about 61%, which is much larger than LiC formed by graphite6In the case of 10%, the structure is likely to change during long-term cycling, so that a high demand is placed on the cycling stability of the graphite material, and further, in consideration of the problems of the coulomb efficiency, rate capability, production cost, and the like of graphite, improvement of the structural design and production method of graphite is urgently required.
Disclosure of Invention
In order to improve the technical problems, the invention aims to provide a three-dimensional porous graphite material.
The invention also aims to provide a preparation method of the three-dimensional porous graphite material.
The invention further aims to provide application of the three-dimensional porous graphite material.
The purpose of the invention is realized by the following technical scheme:
a preparation method of a three-dimensional porous graphite material comprises the following steps:
1) freeze drying the gel of the carbon-containing polymer;
2) carbonizing the dried substance in the step 1) at 2000-3000 ℃.
Wherein, the gel of the carbon-containing polymer in the step 1) contains a solvent A, and the freezing point of the solvent A is higher than the freeze drying temperature.
According to an embodiment of the invention, the freezing point of the solvent a is above 5 ℃, or above 10 ℃, or above 15 ℃ above the freeze-drying temperature.
According to an embodiment of the present invention, the freezing point of the solvent a is, for example, 0 ℃ or higher, or 5 ℃ or higher.
According to an embodiment of the invention, the gel of the carbon-containing polymer in step 1) contains only solvent a.
According to an embodiment of the present invention, the solvent a is, for example, one or more of water, tert-butanol, glacial acetic acid, dimethyl sulfoxide, sulfolane.
According to an embodiment of the invention, in step 1), the temperature of the freeze-drying is-80 to 0 ℃, preferably-50 to 0 ℃, for example the temperature of the freeze-drying is-40 to-10 ℃.
According to an embodiment of the present invention, in the step 1), the freeze-drying cooling rate is, for example, 0 to 200 ℃/s, or 1 to 100 ℃/s, or 2 to 50 ℃/s.
According to an embodiment of the present invention, in the step 1), the freeze-drying time is 0.5 to 2 days, preferably 1 to 2 days.
According to an embodiment of the invention, in step 1), the freezing and drying temperatures are the same or different. For example, freeze-drying at-40 deg.C for 1 day; or, for example, after freezing at-18 ℃ and drying at-40 ℃ for 1 day.
According to an embodiment of the present invention, in the step 2), the temperature of the carbonization treatment is, for example, 2400 to 2900 ℃; or 2600 to 2800 ℃; the time is, for example, 1 to 10 hours, preferably 2 to 6 hours. For example, at 2800 ℃ for 2h, at 2600 ℃ for 2h, or at 2700 ℃ for 2 h.
According to an embodiment of the present invention, the gel of the carbon-containing polymer may be prepared by methods known in the art. The gel of the carbon-containing polymer contains a solvent B, and the solvent B can be the same as or different from the solvent A. Optionally, the prepared gel of the carbon-containing polymer containing the solvent B is placed in the solvent A for soaking, and solvent replacement is carried out, so as to obtain the carbon-containing polymer containing the solvent A. The soaking time may be, for example, 0.25 to 3 days, preferably 0.5 to 2 days, for example, 1 day. In one embodiment, when solvent B is the same as solvent A (e.g., solvent B is solvent A)1) Alternatively, the gel of the carbon-containing polymer containing solvent B may be placed in another solvent A (e.g., solvent A)2) Soaking in water, and performing solvent replacement.
The solvent B can in principle be any solvent as long as a gel of the carbon-containing polymer can be prepared. For example, polar organic solvents, water, aqueous solutions of inorganic salts or solutions of inorganic acids.
According to an embodiment of the invention, the polar organic solution is for example at least one of ethanol, dimethyl sulfoxide, sulfolane, ethylene nitrate, the aqueous inorganic salt solution is for example at least one of thiocyanate, perchlorate, zinc chloride, aqueous lithium bromide, or the inorganic acid solution is for example concentrated nitric acid.
According to an embodiment of the invention, the gel of the carbon-containing polymer is a polyacrylonitrile gel, a phenol resin gel or a polyacrylamide gel.
In one embodiment, the polyacrylonitrile gel is prepared, for example, by dissolving polyacrylonitrile in a solvent under heating, and then cooling to solidify.
According to the embodiment of the invention, the heating condition is, for example, 50-100 ℃, preferably 60-70 ℃, and the dissolving time is, for example, 2-8 hours, preferably 4-6 hours.
Preferably, the cooling is, for example, to solidify the solution after the solution is left at room temperature for a certain period of time, for example, 8 to 100 hours, preferably 12 to 72 hours.
Preferably, the air bubbles in the solution are removed under vacuum before cooling and solidification.
The solvent is, for example, an organic solvent (such as a polar organic solvent), an aqueous inorganic salt solution, or an inorganic acid solution; for example dimethylformamide, dimethyl sulphoxide, sulfolane, ethylene nitrate, thiocyanate, perchlorate, zinc chloride, aqueous lithium bromide, or concentrated nitric acid.
In one embodiment, the phenolic resin gel is prepared, for example, by polymerizing a resole solution under heating conditions to obtain the phenolic resin gel.
According to an embodiment of the present invention, the polymerization reaction is carried out under a catalyst comprising at least one of acetic acid, iminodiacetic acid, sulfuric acid, nitric acid, hexamethylenetetramine.
Preferably, the temperature of the polymerization reaction is 100-150 ℃, and the time of the polymerization reaction is 4-48 h. For example, the reaction is carried out at 110-120 ℃ for 0.2-1 day.
Preferably, the solvent of the resol solution is, for example, one or more of water, ethanol, and tert-butanol.
In one embodiment, the polyacrylamide gel is prepared, for example, by cross-linking polymerization of acrylamide in a solvent to obtain the polyacrylamide gel.
According to an embodiment of the present invention, the crosslinking agent in the crosslinking polymerization reaction is, for example, N' -methylenebisacrylamide, and the initiator is, for example, tetramethylethylenediamine or ammonium persulfate.
Preferably, the temperature of the polymerization reaction is, for example, 50 to 70 ℃.
Preferably, the solvent comprises one or both of water and ethanol.
The invention also provides the three-dimensional porous graphite material prepared by the method.
According to the invention, the three-dimensional porous graphite material has a structure with coexisting micropores, mesopores and macropores, the aperture of the three-dimensional porous graphite material is between 1 and 150nm, and the specific surface area of the three-dimensional porous graphite material is 100 to 1000m2/g。
Preferably, the pore diameter range of the three-dimensional graphitized porous carbon material is 1-100 nm, and more preferably 1-80 nm.
Preferably, the specific surface area of the graphite material is 200-800 m2More preferably, the specific surface area of the graphite material is 300-600 m2The specific surface area of the graphite material is 400-500 m2/g。
Preferably, the thickness of the pore wall of the three-dimensional graphitized porous carbon material is 300-600nm, for example 500 nm.
The application of the three-dimensional porous graphite material in a potassium ion battery, such as the negative electrode material of the potassium ion battery.
Advantageous effects
1. The invention provides a method for preparing a three-dimensional porous graphite material, wherein a gel of a carbon-containing polymer is directly sublimated from a crystal into gas during freeze drying, so that the dried material forms a porous structure. And different solvents can form crystals with different sizes, so that porous graphite materials with different pore diameters can be obtained by selecting different solvents.
2. The three-dimensional porous graphite material prepared by the invention has the characteristics of multiple active sites, high graphitization degree and hierarchical porosity. The hierarchical porous structure in the carbon material is beneficial to the transportation and ion diffusion of electrolyte, reduces the local volume expansion in the process of lithium ion insertion and extraction in the charging and discharging processes, and can effectively improve the rate capability and the cycle performance of the battery. The high graphitization degree brings high conductivity, and is beneficial to electron transmission.
3. The three-dimensional porous graphite material prepared by the invention has higher specific surface area, and can be used for different purposes by forming different groups on the surface through a physical or chemical mode.
Drawings
Fig. 1 is a scanning electron microscope image of the three-dimensional porous graphite material prepared in example 1 at a scale of 50 μm.
Fig. 2 is a scanning electron microscope image of the three-dimensional porous graphite material prepared in example 1 at a scale of 5 μm.
Fig. 3 is a specific surface area test graph of the three-dimensional porous graphite material prepared in example 1.
Fig. 4 is a scanning electron microscope image of the three-dimensional porous graphite material prepared in example 3.
Fig. 5 is an XRD test pattern of the three-dimensional porous graphite material prepared in example 3.
Fig. 6 is a Raman test chart of the three-dimensional porous graphite material prepared in example 3.
FIG. 7 is a scanning electron micrograph of the three-dimensional porous graphite material prepared in example 6.
Detailed Description
The materials of the present invention, methods of making the same, and uses thereof, are described in further detail below with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.
Example 1
1. Adding iminodiacetic acid serving as a catalyst into resol with the water content of 95%, wherein the mass ratio of the resol to the iminodiacetic acid is 14:1, uniformly stirring, placing in an autoclave at 115 ℃, and standing for 0.5 day to obtain a reaction intermediate product A;
2. placing the reaction intermediate product A into tert-butyl alcohol, and soaking for 6 hours at 25 ℃ to obtain a reaction product B;
3. and (3) freezing the reaction product B by using liquid nitrogen, carrying out freeze drying at-40 ℃, and carbonizing the obtained product at 2600 ℃ for 2 hours to obtain the three-dimensional porous graphite material.
Fig. 1 and fig. 2 are scanning electron micrographs of the three-dimensional porous graphite material prepared in this example under different scales, and it can be seen from the drawings that the interior of the material prepared in this example is of a porous structure and has different pore sizes, which indicates that the prepared graphite material has more pores, and is beneficial to the entry of electrolyte and ion diffusion; referring to fig. 3, it can be known that the three-dimensional porous graphite material has a high specific surface area and a multi-level pore distribution, which is helpful for the diffusion of ions in the electrolyte.
Example 2
1. Adding acetic acid serving as a catalyst into resol with the water content of 95%, wherein the mass ratio of the resol to the acetic acid is 20:1, uniformly stirring, putting into an autoclave, and standing at 115 ℃ for 0.5 day to obtain a reaction intermediate product A;
2. directly freezing the reaction product A by using liquid nitrogen without soaking tert-butyl alcohol, and carrying out freeze drying at-40 ℃ for 24h to obtain a product, and carbonizing the obtained product at 2600 ℃ for 2h to obtain a three-dimensional porous graphite material;
referring to fig. 4, which is a scanning electron microscope image of the three-dimensional porous graphite material prepared in this example, it can be seen from the figure that the pore structure of the material prepared in this example is greatly different from that of the material prepared in example 1, and the thickness of the pore wall is about 500nm, which indicates that the ice crystal of water is greatly different from that of tert-butyl alcohol, which results in the change of the pore structure in the carbon material, and thus the distribution of macropores in the material can be controlled.
Example 3
1. Polyacrylonitrile having an average molecular weight of 8 ten thousand was used, as indicated by polyacrylonitrile: the mass ratio of dimethyl sulfoxide is 15: 85, stirring in a water bath at 70 ℃ for 5 hours to uniformly dissolve polyacrylonitrile, and placing in a vacuum drying oven at 50 ℃ for 1 hour to remove bubbles to obtain a polyacrylonitrile solution;
2. uniformly pouring the polyacrylonitrile solution into a mold, and standing at room temperature for 12 hours to solidify the polyacrylonitrile solution to obtain an intermediate product A;
3. and (3) putting the intermediate product A into tert-butyl alcohol, soaking for 6 hours at 25 ℃ to obtain a reaction product B, freezing the reaction product B by using liquid nitrogen, freeze-drying for 1 day at-40 ℃, and carbonizing the obtained product for 2 hours at 2700 ℃ to obtain the three-dimensional porous graphite material.
Fig. 5 is an XRD test chart of the three-dimensional porous graphite material prepared in this example, and it can be known from the sharp 002 peak in the chart that the interlayer spacing of the graphite material prepared in this example is relatively concentrated, and the graphitized material has a relatively high graphitization degree.
Fig. 6 is a raman test chart of the three-dimensional porous graphite material prepared in this example, and it can be seen from the chart that the difference between the D peak and the G peak of the graphite material prepared in this example is large, which indicates that the material has many graphite structures.
Example 4
1. Mixing sodium thiocyanate and deionized water according to the mass ratio of 40:60, and stirring until the sodium thiocyanate and the deionized water are completely dissolved to obtain a sodium thiocyanate solution;
2. polyacrylonitrile having an average molecular weight of 10 ten thousand was used, as indicated by polyacrylonitrile: the mass ratio of the sodium thiocyanate solution is 20: 80, stirring for 6 hours in water bath at 60 ℃, and placing in a vacuum drying oven at 40 ℃ for 1 hour to remove bubbles to prepare a polyacrylonitrile solution;
3. uniformly pouring the polyacrylonitrile solution into a mold, and standing at room temperature for 72 hours to solidify the polyacrylonitrile solution to obtain an intermediate product A;
4. and (3) putting the intermediate product A into tert-butyl alcohol, soaking for 6 hours at 25 ℃ to obtain a reaction product B, freezing with liquid nitrogen, freeze-drying for 1 day at-40 ℃, and carbonizing the obtained product for 2 hours at 2600 ℃ to obtain the three-dimensional porous graphite material.
Example 5
1. Mixing zinc chloride and deionized water according to the mass ratio of 60:40, and stirring until the zinc chloride and the deionized water are completely dissolved to obtain a zinc chloride aqueous solution;
2. polyacrylonitrile having an average molecular weight of 8 ten thousand was used, as indicated by polyacrylonitrile: the mass ratio of the zinc chloride aqueous solution is 13: 87, stirring for 4 hours in water bath at 60 ℃, and placing in a vacuum drying oven at 40 ℃ for 1 hour to remove bubbles to prepare a polyacrylonitrile solution;
3. uniformly pouring the polyacrylonitrile solution into a mold, and standing at room temperature for 48 hours to solidify the polyacrylonitrile solution to obtain an intermediate product A;
4. placing the intermediate product A into tert-butyl alcohol, and soaking for 1 day at 25 ℃ to obtain a reaction product B;
5. freezing the reaction product B in a refrigerator at the temperature of 18 ℃ below zero, freeze-drying the reaction product B for 1 day at the temperature of 40 ℃ below zero, and carbonizing the obtained product at the temperature of 2800 ℃ for 2 hours to obtain the three-dimensional porous graphite material.
Example 6
1. Mixing acrylamide, ammonium persulfate and N, N' -methylene bisacrylamide in a mass ratio of 1600:8:1, adding 40ml of deionized water, stirring at room temperature until the mixture is completely dissolved, and placing in a vacuum drying oven at 40 ℃ for 1 hour to remove bubbles;
2. transferring the obtained degassed solution into a glass mold, and placing the glass mold in an oven at 60 ℃ overnight to perform polymerization to form a gel product A;
3. placing the gel product A into tert-butyl alcohol, and soaking for 1 day at 25 ℃ to obtain a reaction product B;
4. freezing the reaction product B in a refrigerator at the temperature of 18 ℃ below zero, freezing and drying the reaction product B for 1 day at the temperature of 40 ℃ below zero, and carbonizing the obtained product at the temperature of 2800 ℃ for 2 hours to obtain the three-dimensional porous graphite material.
Comparative example 1
1. Adding iminodiacetic acid serving as a catalyst into resol with the water content of 95%, wherein the mass ratio of the resol to the iminodiacetic acid is 14:1, uniformly stirring, placing in an autoclave at 115 ℃, and standing for 0.5 day to obtain a reaction intermediate product A;
2. putting the reaction product A into a forced air drying oven, and drying for 24h at 80 ℃ to obtain a dried product B;
3. and (3) carrying out graphitization treatment on the obtained dried product, wherein the heating rate is 5 ℃/min, and keeping the temperature at 2600 ℃ for 2 hours to obtain the phenolic resin graphite material.
Comparative example 2
1. Polyacrylonitrile with the average molecular weight of 8 ten thousand is prepared according to the following formula: the mass ratio of dimethyl sulfoxide is 15: 85, stirring in a water bath at 70 ℃ for 5 hours to uniformly dissolve polyacrylonitrile, and placing in a vacuum drying oven at 50 ℃ for 1 hour to remove bubbles to prepare a polyacrylonitrile solution;
2. uniformly pouring the polyacrylonitrile solution into a mold, and standing at room temperature for 12 hours to solidify the polyacrylonitrile solution to obtain an intermediate product A;
3. putting the intermediate product A into a forced air drying oven, and drying for 24h at 80 ℃ to obtain a dried product B;
4. and (3) carrying out graphitization treatment on the obtained dried product, wherein the heating rate is 5 ℃/min, and keeping the temperature at 2600 ℃ for 2 hours to obtain the polyacrylonitrile graphite material.
Comparative example 3
1. Mixing acrylamide, ammonium persulfate and N, N' -methylene bisacrylamide in a mass ratio of 1600:8:1, adding 40ml of deionized water, stirring at room temperature until the mixture is completely dissolved, and placing in a vacuum drying oven at 40 ℃ for 1 hour in vacuum to remove bubbles;
2. transferring the obtained degassed solution into a glass mold, and placing the glass mold in an oven at 60 ℃ overnight to perform polymerization to form a gel product A;
3. putting the gel product A into a forced air drying oven, and drying for 24h at 80 ℃ to obtain a dried product B;
4. and (3) carrying out graphitization treatment on the obtained dried product, wherein the heating rate is 5 ℃/min, and carrying out heat preservation at 2600 ℃ for 2 hours to obtain the polyacrylamide graphite material.
Test example
The physical and chemical indexes of the materials prepared in the above examples 1, 3, 7 and comparative examples 1 to 3 were tested, and the specific test results are as follows:
electrochemical performance test, the materials prepared in examples 1, 3 and 7 and comparative examples 1 to 3 are used as negative electrode materials (to-be-tested negative electrode materials for short)
The semi-electric test method comprises the following steps: uniformly mixing the negative electrode material to be measured, namely conductive carbon black (SP), carboxymethyl cellulose (CMC) and Styrene Butadiene Rubber (SBR) in a mass ratio of 95:1:1.5:2.5, coating the mixture on a copper foil, and drying the coated pole piece in a vacuum drying oven at 120 ℃ for 12 hours. The simulated battery assembly is carried out in a Braun glove box protected by nitrogen, the electrolyte is 1M-KFSI + EC: DEC (1M acetyl carbonate solution of potassium bifluorosulfonimide: dimethyl ether) (the volume ratio is 1:1), the simulated battery test is carried out in a 5V and 10mA Xinwei battery test cabinet by taking a metal potassium sheet as a counter electrode, the charging and discharging voltage is 0.01-3V, the charging and discharging rate is 0.2C, and the obtained first discharge capacity and the first charging and discharging efficiency are shown in Table 1.
The full battery test method comprises the following steps: the anode material to be tested is used as an anode, Prussian blue potassium is used as a cathode, a solution of 1M-KFSI + EC: DEC (volume ratio 1:1) is used as an electrolyte to assemble a full cell, normal-temperature charging and discharging are carried out at the multiplying power of 0.2C and 2.5C, the voltage range is 2.0-4V, and the tested cycle performance is shown in Table 1.
The maximum charging multiplying power test method comprises the following steps: and respectively charging the battery cell to 100% SOC with different multiplying powers, disassembling the battery cell, and observing the potassium precipitation condition of the negative plate.
TABLE 1 test results of physical and chemical properties and electrochemical properties of graphite anode materials
As can be seen from Table 1, the graphite negative electrode material prepared by the method has better rate capability and cycle performance. The preparation method has the advantages of simple preparation process, low cost and higher practicability, and can greatly improve the service performance of the potassium ion battery.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A preparation method of a three-dimensional porous graphite material is characterized by comprising the following steps:
1) freeze drying the gel of the carbon-containing polymer;
2) carbonizing the dried substance in the step 1) at 2000-3000 ℃.
Wherein, the gel of the carbon-containing polymer in the step 1) contains a solvent A, and the freezing point of the solvent A is higher than the freeze drying temperature.
2. The method of claim 1, wherein: the freezing point of the solvent A is higher than the freeze-drying temperature by more than 5 ℃, or more than 10 ℃, or more than 15 ℃.
Preferably, the freezing point of the solvent a is, for example, 0 ℃ or more, or 5 ℃ or more.
Preferably, the gel of the carbon-containing polymer in step 1) contains only solvent a.
Preferably, the solvent a is, for example, one or more of water, tert-butanol, glacial acetic acid, dimethyl sulfoxide, and sulfolane.
3. The method of claim 1, wherein: in the step 1), the temperature of the freeze drying is-80-0 ℃, preferably-50-0 ℃, for example, the temperature of the freeze drying is-40-10 ℃.
Preferably, in the step 1), the freeze-drying time is 0.5-2 days, and preferably 1-2 days.
4. The method of claim 1, wherein: the temperature of the carbonization treatment is 2400-2900 ℃ for example; or 2600 to 2800 ℃; the time is, for example, 1 to 10 hours, preferably 2 to 6 hours.
5. The production method according to any one of claims 1 to 4, characterized in that: the gel containing the carbon-containing polymer can be prepared by a method known in the prior art, and the prepared gel containing the carbon-containing polymer contains a solvent B, and the solvent B can be the same as or different from the solvent A.
Optionally, the prepared gel of the carbon-containing polymer containing the solvent B is placed in the solvent A for soaking, and solvent replacement is carried out, so as to obtain the carbon-containing polymer containing the solvent A.
The soaking time is preferably 0.25 to 3 days, for example.
6. The method of claim 5, wherein: the solvent B is, for example, an organic solvent, water, an aqueous solution of an inorganic salt, or an inorganic acid solution.
Preferably, the organic solvent is at least one of ethanol, dimethyl sulfoxide, sulfolane and ethylene nitrate, the inorganic salt aqueous solution is at least one of thiocyanate, perchlorate, zinc chloride and lithium bromide aqueous solution, and the inorganic acid solution is concentrated nitric acid.
7. The method of claim 5, wherein: the gel of the carbon-containing polymer is polyacrylonitrile gel, phenolic resin gel or polyacrylamide gel.
8. A three-dimensional porous graphite material produced by the method of any one of claims 1 to 7.
9. The three-dimensional porous graphite material according to claim 8, wherein the material has a structure in which micropores, mesopores and macropores coexist, and has a pore diameter of 1 to 150nm and a specific surface area of 100 to 1000m2/g。
10. Use of the three-dimensional porous graphite material according to claim 8 or 9 in a potassium ion battery, for example as a negative electrode material for a potassium ion battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111376551.4A CN114180565A (en) | 2021-11-19 | 2021-11-19 | Three-dimensional porous graphite material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111376551.4A CN114180565A (en) | 2021-11-19 | 2021-11-19 | Three-dimensional porous graphite material and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114180565A true CN114180565A (en) | 2022-03-15 |
Family
ID=80602215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111376551.4A Pending CN114180565A (en) | 2021-11-19 | 2021-11-19 | Three-dimensional porous graphite material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114180565A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201615542A (en) * | 2014-09-09 | 2016-05-01 | 東北泰克諾亞奇股份有限公司 | Method for producing porous graphite, and porous graphite |
| CN107032323A (en) * | 2016-02-02 | 2017-08-11 | 上海交通大学 | A kind of preparation method of flake porous nano material |
| US20170240424A1 (en) * | 2014-07-29 | 2017-08-24 | Agency For Science, Technology And Research | Method of preparing a porous carbon material |
| US20190127227A1 (en) * | 2016-07-22 | 2019-05-02 | China Petroleum And Chemical Corporation | Carbon-based porous material and preparation method and use thereof |
| CN113023705A (en) * | 2021-02-05 | 2021-06-25 | 江苏大学 | Preparation method of hydrogen-rich carbon material and application of hydrogen-rich carbon material in lithium-sodium-potassium energy storage |
-
2021
- 2021-11-19 CN CN202111376551.4A patent/CN114180565A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170240424A1 (en) * | 2014-07-29 | 2017-08-24 | Agency For Science, Technology And Research | Method of preparing a porous carbon material |
| TW201615542A (en) * | 2014-09-09 | 2016-05-01 | 東北泰克諾亞奇股份有限公司 | Method for producing porous graphite, and porous graphite |
| CN107032323A (en) * | 2016-02-02 | 2017-08-11 | 上海交通大学 | A kind of preparation method of flake porous nano material |
| US20190127227A1 (en) * | 2016-07-22 | 2019-05-02 | China Petroleum And Chemical Corporation | Carbon-based porous material and preparation method and use thereof |
| CN113023705A (en) * | 2021-02-05 | 2021-06-25 | 江苏大学 | Preparation method of hydrogen-rich carbon material and application of hydrogen-rich carbon material in lithium-sodium-potassium energy storage |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106941167B (en) | Porous composite negative electrode material of lithium ion battery and preparation method thereof | |
| CN105845936B (en) | Preparation method of modified hard carbon negative electrode material for lithium ion battery | |
| CN109243853B (en) | Method for preparing high-specific-capacity nano composite material by adopting double templates | |
| CN108394884A (en) | A kind of preparation method of chitosan-based high-specific surface area nitrogen/phosphor codoping carbon nanosheet | |
| CN105390672A (en) | Preparation method for three-dimensional nitrogen-doped mesoporous carbon ultra-thin nanosheet material | |
| CN109004220B (en) | Boric acid compound modified lithium ion battery silicon cathode and preparation method thereof | |
| JP2015095455A (en) | Negative electrode material of on-vehicle energy storage lithium ion battery, and manufacturing method thereof | |
| CN104282896A (en) | Nitrogen-doped carbon-coated graphite negative electrode material and preparation method thereof | |
| CN108110315B (en) | Preparation method of self-repairing polymer electrolyte of lithium ion battery | |
| CN110707288B (en) | Silicon-based negative electrode active material and preparation method and application thereof | |
| CN107565103B (en) | Porous silicon/graphene composite material and preparation method and application thereof | |
| CN111009648B (en) | Silicon-carbon composite material and preparation method thereof | |
| CN107394265B (en) | Method for preparing polymethyl methacrylate gel electrolyte microporous membrane by double-solvent stepwise phase inversion | |
| CN102227019A (en) | Method for preparing tin-carbon composite material for cathode of lithium ion battery | |
| CN111063891B (en) | Preparation method of aqueous conductive adhesive | |
| Xu et al. | Polymeric one-side conductive Janus separator with preferably oriented pores for enhancing lithium metal battery safety | |
| CN110305321B (en) | Preparation method of polypyrrole quantum dot and sodium-sulfur battery diaphragm | |
| CN102005559B (en) | Method for preparing artificial graphite cathode material for lithium ion batteries | |
| CN116741992B (en) | Porous hard carbon material and preparation method thereof, negative electrode plate and sodium ion battery | |
| CN111785892B (en) | Preparation method of lithium-sulfur battery composite diaphragm | |
| CN114180565A (en) | Three-dimensional porous graphite material and preparation method and application thereof | |
| CN104241606A (en) | Preparation method of lithium iron phosphate positive plate with high rate and superior low-temperature performance | |
| CN116598488A (en) | Pre-sodium hard carbon anode material and preparation method and application thereof | |
| CN113036087B (en) | Ultrahigh-sulfur-content two-dimensional molecular brush and preparation method and application thereof | |
| CN105720269B (en) | A kind of big interlamellar spacing graphite cathode material preparation method of sodium-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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220315 |