CN115911307A - Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery - Google Patents
Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery Download PDFInfo
- Publication number
- CN115911307A CN115911307A CN202211387276.0A CN202211387276A CN115911307A CN 115911307 A CN115911307 A CN 115911307A CN 202211387276 A CN202211387276 A CN 202211387276A CN 115911307 A CN115911307 A CN 115911307A
- Authority
- CN
- China
- Prior art keywords
- lithium titanate
- carbon quantum
- quantum dot
- dot composite
- composite material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title claims abstract description 123
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 122
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 122
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 94
- 239000002131 composite material Substances 0.000 title claims abstract description 81
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000002243 precursor Substances 0.000 claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 34
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims abstract description 30
- GHDSNRQFECQVII-UHFFFAOYSA-N [Ti].OOO Chemical compound [Ti].OOO GHDSNRQFECQVII-UHFFFAOYSA-N 0.000 claims abstract description 17
- PQVSTLUFSYVLTO-UHFFFAOYSA-N ethyl n-ethoxycarbonylcarbamate Chemical compound CCOC(=O)NC(=O)OCC PQVSTLUFSYVLTO-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 15
- GLXDVVHUTZTUQK-UHFFFAOYSA-M lithium hydroxide monohydrate Substances [Li+].O.[OH-] GLXDVVHUTZTUQK-UHFFFAOYSA-M 0.000 claims abstract description 15
- 229940040692 lithium hydroxide monohydrate Drugs 0.000 claims abstract description 15
- 238000001354 calcination Methods 0.000 claims abstract description 13
- 239000004094 surface-active agent Substances 0.000 claims abstract description 13
- 238000003756 stirring Methods 0.000 claims abstract description 12
- 239000010936 titanium Substances 0.000 claims abstract description 12
- HKDXPUPTIQCIPH-UHFFFAOYSA-L [O--].[O--].[O--].O[Ti+3].O[Ti+3] Chemical compound [O--].[O--].[O--].O[Ti+3].O[Ti+3] HKDXPUPTIQCIPH-UHFFFAOYSA-L 0.000 claims abstract description 6
- 239000012298 atmosphere Substances 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims abstract description 6
- 230000001681 protective effect Effects 0.000 claims abstract description 6
- 238000005530 etching Methods 0.000 claims abstract description 5
- 238000002156 mixing Methods 0.000 claims abstract description 3
- 239000000758 substrate Substances 0.000 claims abstract 4
- 239000002135 nanosheet Substances 0.000 claims description 23
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 13
- 229910001416 lithium ion Inorganic materials 0.000 claims description 13
- -1 polyoxyethylene Polymers 0.000 claims description 12
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 9
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 claims description 9
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 claims description 8
- 229910001425 magnesium ion Inorganic materials 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 239000003792 electrolyte Substances 0.000 claims description 7
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 6
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 6
- 239000004743 Polypropylene Substances 0.000 claims description 6
- 229920001155 polypropylene Polymers 0.000 claims description 6
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 4
- 239000002055 nanoplate Substances 0.000 claims description 4
- 239000004698 Polyethylene Substances 0.000 claims description 3
- 239000002202 Polyethylene glycol Substances 0.000 claims description 3
- 229920001400 block copolymer Polymers 0.000 claims description 3
- ZPIRTVJRHUMMOI-UHFFFAOYSA-N octoxybenzene Chemical compound CCCCCCCCOC1=CC=CC=C1 ZPIRTVJRHUMMOI-UHFFFAOYSA-N 0.000 claims description 3
- 229920000573 polyethylene Polymers 0.000 claims description 3
- 229920001223 polyethylene glycol Polymers 0.000 claims description 3
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 3
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 3
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 3
- 229920000428 triblock copolymer Polymers 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 239000008367 deionised water Substances 0.000 description 23
- 229910021641 deionized water Inorganic materials 0.000 description 23
- 239000000203 mixture Substances 0.000 description 19
- 239000000243 solution Substances 0.000 description 18
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 15
- 239000000463 material Substances 0.000 description 12
- 239000000843 powder Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 11
- 230000014759 maintenance of location Effects 0.000 description 10
- 239000010410 layer Substances 0.000 description 8
- 238000001878 scanning electron micrograph Methods 0.000 description 8
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 7
- 238000001914 filtration Methods 0.000 description 7
- 239000012046 mixed solvent Substances 0.000 description 7
- 238000005406 washing Methods 0.000 description 7
- UQZIWOQVLUASCR-UHFFFAOYSA-N alumane;titanium Chemical compound [AlH3].[Ti] UQZIWOQVLUASCR-UHFFFAOYSA-N 0.000 description 6
- 239000012300 argon atmosphere Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000010406 cathode material Substances 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 241000209094 Oryza Species 0.000 description 3
- 235000007164 Oryza sativa Nutrition 0.000 description 3
- 239000007772 electrode material Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 235000009566 rice Nutrition 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- YZSKZXUDGLALTQ-UHFFFAOYSA-N [Li][C] Chemical compound [Li][C] YZSKZXUDGLALTQ-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a lithium titanate/carbon quantum dot composite material, a preparation method thereof and a battery, wherein the preparation method comprises the steps of: step 1, preparing layered titanium carbide: mixing Ti 3 AlC 2 Placing the titanium carbide substrate in a hydrofluoric acid solution, stirring the titanium carbide substrate and the hydrofluoric acid solution for etching reaction to obtain layered titanium carbide; step 2, preparing a lithium titanate/carbon quantum dot composite precursor: dispersing layered titanium carbide, lithium hydroxide monohydrate, a surfactant and titanium oxyhydroxide in water, and carrying out hydrothermal reaction to obtain a lithium titanate/carbon quantum dot composite precursor; wherein, the mol ratio of the layered titanium carbide, the surfactant, the lithium hydroxide monohydrate and the hydroxyl titanium oxide is 1 (0.1-1): (25-150): 90-500); step 3, preparing the lithium titanate/carbon quantum dot composite material: and (3) calcining the lithium titanate/carbon quantum dot composite precursor in a protective atmosphere to obtain the lithium titanate/carbon quantum dot composite material.
Description
Technical Field
The invention relates to the field of batteries, in particular to a lithium titanate/carbon quantum dot composite material, a preparation method thereof, a lithium ion battery and a magnesium ion battery.
Background
Lithium titanate is an ideal electrode material for lithium ion batteries and magnesium ion batteries, has a high and stable discharge voltage platform, does not react with electrolyte to form an SEI film, is not easy to cause the precipitation of metal lithium or magnesium, has good safety performance, has a zero-strain structure, has good cycling stability, and has great research value and commercial application prospect when being used as the electrode material for the lithium ion batteries and the magnesium ion batteries. However, the electronic conductivity and ionic conductivity of lithium titanate are relatively low, so that the lithium titanate has poor charge-discharge rate performance when used as an electrode material, and further development of lithium titanate is limited.
In view of the above drawbacks of lithium titanate, researchers often improve the rate capability of lithium titanate by adding carbon materials with high electron transport properties, such as CN201210029181.1 and cn201610797550.X. However, the materials are all composed of lithium titanate particles coated by a carbon layer, and the specific gravity of carbon is large, so that the content of lithium carbonate with electrochemical activity in the carbon-lithium titanate composite material is not high enough. In addition, although the carbon coating layer increases the migration rate of electrons, the carbon layer may form a solid electrolyte film (SEI) during charge and discharge, resulting in irreversible capacity loss.
Disclosure of Invention
The invention aims to provide a lithium titanate/carbon quantum dot composite material which is not easy to form an SEI film, a preparation method thereof and a battery.
In order to achieve the purpose, the invention provides a preparation method of a lithium titanate/carbon quantum dot composite material, which comprises the following steps:
step 2, preparing a lithium titanate/carbon quantum dot composite precursor: dispersing the layered titanium carbide, lithium hydroxide monohydrate, a surfactant and titanium oxyhydroxide in water, and carrying out hydrothermal reaction to obtain a lithium titanate/carbon quantum dot composite precursor; wherein, the mol ratio of the layered titanium carbide, the surfactant, the lithium hydroxide monohydrate and the hydroxyl titanium oxide is 1 (0.1-1): (25-150): 90-500);
step 3, preparing the lithium titanate/carbon quantum dot composite material: and calcining the lithium titanate/carbon quantum dot composite precursor in a protective atmosphere to obtain the lithium titanate/carbon quantum dot composite material.
Optionally, the hydrofluoric acid solution is 30-50% by mass.
Optionally, the surfactant comprises: any one of polyvinylpyrrolidone, cetyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate, polyoxyethylene polypropylene ether block copolymer, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and polyethylene glycol octyl phenyl ether.
Optionally, in step 2, the temperature of the hydrothermal reaction is 140-200 ℃ and the time is 10-24h.
Optionally, in step 3, the calcining temperature is 500-700 ℃, and the heating rate is 2-10 ℃/min.
Optionally, in step 3, the protective atmosphere is Ar and N 2 At least one of (1).
The invention also provides a lithium titanate/carbon quantum dot composite material prepared by the preparation method, which comprises the following components in parts by weight: the lithium titanate nano-plate comprises a lithium titanate nano-plate and carbon quantum dots, wherein the carbon quantum dots are uniformly embedded in the lithium titanate nano-plate.
Optionally, the thickness of the lithium titanate nanosheet is 10-30nm.
The present invention also provides a lithium ion battery, comprising: the lithium titanate/carbon quantum dot composite material comprises a positive electrode, a negative electrode and electrolyte, wherein the negative electrode is made of the lithium titanate/carbon quantum dot composite material.
The present invention also provides a magnesium ion battery including: the lithium titanate/carbon quantum dot composite material comprises a positive electrode, a negative electrode and electrolyte, wherein the positive electrode is made of the lithium titanate/carbon quantum dot composite material.
The preparation principle of the lithium titanate/carbon quantum dot composite material is as follows:
the layered titanium carbide is prepared by an acid etching method of carbon-aluminum-titanium, and then the layered titanium carbide is used as a structure directing agent to prepare the micron-sized flower-shaped lithium titanate/carbon quantum dot composite material. The layered titanium carbide is used as a structure directing agent to enable lithium titanate to form a flower shape along the surface of the lithium titanate in situ, and simultaneously, the titanium carbide is also used as a reactant to provide a titanium source to form lithium titanate nano-sheets and a carbon source to form carbon quantum dots, and the carbon quantum dots are uniformly embedded into the lithium titanate nano-sheets.
Compared with the prior art, the invention has the following beneficial effects:
(1) The lithium titanate/carbon quantum dot composite material is composed of carbon quantum dots and lithium titanate nanosheets, the lithium titanate nanosheets are used as main frameworks, the carbon quantum dots are uniformly embedded into the lithium titanate nanosheets, and the lithium titanate is not easy to react with an electrolyte solution to form an SEI film due to the fact that the lithium titanate is used as the main frameworks, so that the SEI film is not easy to generate in the using process of the material.
(2) The embedding of the carbon quantum dots of the lithium titanate/carbon quantum dot composite material promotes the rapid transmission of electrons and ions, and improves the electrochemical performance of the lithium titanate composite material.
(3) The lithium titanate/carbon quantum dot composite material disclosed by the invention is of a micron-sized flower-like structure, is large in specific surface area, is fully contacted with an electrolyte, and provides more active sites.
Drawings
Fig. 1 is a scanning electron micrograph of the lithium titanate/carbon quantum dot composite material of the present invention. Fig. 1 (a) is a scanning electron micrograph of a lithium titanate/carbon quantum dot composite material at low magnification; fig. 1 (b) is a scanning electron micrograph of the lithium titanate/carbon quantum dot composite material at high magnification.
Fig. 2 is a scanning electron micrograph of a lithium titanate material of comparative example 1. Fig. 2 (a) is a scanning electron micrograph of a lithium titanate material of comparative example 1 at a low magnification; fig. 2 (b) is a scanning electron micrograph of the lithium titanate material of comparative example 1 at high magnification.
Fig. 3 is a transmission electron micrograph of the lithium titanate/carbon quantum dot composite material of example 1. Fig. 3 (a) is a scanning electron micrograph of a lithium titanate material of comparative example 1 at a low magnification; fig. 3 (b) is a scanning electron micrograph of the lithium titanate material of comparative example 1 at a high magnification.
Fig. 4 is a comparison graph of cycle performance of the lithium titanate/carbon quantum dot composite of example 1 and the lithium titanate of comparative example 1 (lithium ion battery).
Fig. 5 is a cycle curve of the lithium titanate/carbon quantum dot composite of example 1 in a lithium ion battery.
Fig. 6 is a comparison graph of cycle performance (magnesium ion battery) for the lithium titanate/carbon quantum dot composite of example 1 and the lithium titanate of comparative example 1.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
As shown in fig. 1, the present invention provides a lithium titanate/carbon quantum dot composite material, comprising: lithium titanate nanosheets and carbon quantum dots, wherein the lithium titanate nanosheets are assembled into a micron-sized flower shape, and the carbon quantum dots are uniformly embedded into the micron-sized flower shapeFlower-shaped lithium titanate nanosheets. The lithium titanate/carbon quantum dot composite material has the particle size of about 1-10 mu m, the thickness of lithium titanate nanosheet of about 10-30nm, the size of carbon quantum dot of about 1-5nm and the specific surface area of about 70-80m 2 (ii) in terms of/g. The lithium titanate/carbon quantum dot composite material is composed of carbon quantum dots and lithium titanate nanosheets, the lithium titanate nanosheets are used as main frameworks, the carbon quantum dots are uniformly embedded into the lithium titanate nanosheets, and the lithium titanate is not easy to react with an electrolyte solution to form an SEI film due to the fact that the lithium titanate is used as the main frameworks, so that the SEI film is not easy to generate in the using process of the material.
The invention also provides a preparation method of the lithium titanate/carbon quantum dot composite material, which comprises the following steps:
specifically, first, ti 3 AlC 2 Adding into HF with a certain concentration, stirring to react to make HF fully etch Ti 3 AlC 2 To obtain the lamellar TiC. Repeatedly cleaning laminated TiC with deionized water, removing HF, and oven drying at 70 deg.C for 10 hr to obtain laminated Ti 3 C 2 。
Step 2, preparing a lithium titanate/carbon quantum dot composite precursor: dispersing layered titanium carbide, lithium hydroxide monohydrate, a surfactant and titanium oxyhydroxide in water, and carrying out hydrothermal reaction to obtain a lithium titanate/carbon quantum dot composite precursor;
specifically, firstly, the layered titanium carbide is dispersed in deionized water, then lithium hydroxide monohydrate and a surfactant are added, stirring is carried out for a proper time, and then titanium oxyhydroxide is added, and stirring is carried out uniformly to carry out hydrothermal reaction. After the hydrothermal reaction is finished, the obtained lithium titanate/carbon quantum dot composite precursor is washed by absolute ethyl alcohol and deionized water so as to wash away the surfactant and the alkaline solution on the surface of the precursor.
In the invention, the function of the surfactant is as follows: in the reaction process, the surface of the titanium carbide is treated, the reaction area of the titanium carbide and the hydroxyl titanium oxide is promoted, and the reaction degree is improved. The surfactant of the present invention includes: any one of polyvinylpyrrolidone, cetyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate, polyoxyethylene polypropylene ether block copolymer, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and polyethylene glycol octyl phenyl ether.
Step 3, preparing the lithium titanate/carbon quantum dot composite material: and calcining the lithium titanate/carbon quantum dot composite precursor in a protective atmosphere to obtain the lithium titanate/carbon quantum dot composite material.
Comparative example 1
2.382g of tetrabutyl titanate is dissolved in 50mL of absolute ethyl alcohol/water mixed solvent, is continuously stirred for 1 hour and then is filtered, and then is baked for 3 hours at 80 ℃ to obtain the hydroxyl titanium oxide.
0.018g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were dispersed in 70mL of deionized water and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (3) washing the precursor with absolute ethyl alcohol and deionized water for three times respectively to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining the precursor for 6 hours at 550 ℃ at the heating rate of 2 ℃/min to obtain the lithium titanate material. As shown in FIG. 2, the lithium titanate prepared in comparative example 1 is a particle with a random morphology, and the specific surface area of the material is 56.5m 2 /g。
Example 1
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate was dissolved in 50mL of an anhydrous ethanol/water mixed solvent, and continuously stirred for 1 hour, followed by filtration and baking at 80 ℃ for 3 hours to obtain titanium oxyhydroxide.
0.018g of titanium carbide powder was dispersed in 70mL of deionized water, and then 0.018g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (2) washing with absolute ethyl alcohol and deionized water for three times respectively to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining at the temperature rise rate of 2 ℃/min and the temperature of 550 ℃ for 6 hours to obtain the lithium titanate/carbon quantum dot composite material, wherein the content of the carbon quantum dots in the composite material is about 0.8wt%.
As shown in fig. 3, it is clear from fig. 3 that carbon quantum dots having a size of about 4nm are uniformly embedded in the lithium titanate nanosheet.
As shown in FIG. 4, electrochemical performance tests show that the lithium titanate/carbon quantum dot composite material has a first discharge specific capacity of 175.4mAh/g and a 500-cycle capacity retention rate of 95.5% at a current density of 875mA/g, and is superior to the lithium titanate in comparative example 1 in performance (the first discharge specific capacity of 153.9mAh/g and the 500-cycle retention rate of 91.1%).
As shown in fig. 5, when the lithium titanate/carbon quantum dot composite material of the embodiment is used as a negative electrode of a lithium ion battery, the discharge specific capacity is still as high as 160.7mAh/g after 5000 cycles, and the capacity retention rate is 91.3%.
As shown in fig. 6, when the lithium titanate/carbon quantum dot composite material of the embodiment is used as a magnesium ion battery anode, under a current density of 100mA/g, the amount of Chu Meirong of the composite material is 185.2mAh/g, and the capacity retention rate after 250 cycles is 93.2%.
Example 2
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate was dissolved in 50mL of an anhydrous ethanol/water mixed solvent, and stirred continuously for 1 hour, then filtered and baked at 80 ℃ for 3 hours to obtain titanium oxyhydroxide.
0.032g of titanium carbide powder was dispersed in 70mL of deionized water, then 0.018g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (2) washing with absolute ethyl alcohol and deionized water for three times respectively to obtain a precursor, and then placing the precursor in a tubular furnace in a nitrogen atmosphere, and calcining at the temperature rise rate of 5 ℃/min and the temperature of 550 ℃ for 6 hours to obtain the lithium titanate/carbon quantum dot composite material. Experiments prove that the content of the carbon quantum dots in the composite material is about 1.1wt%. The lithium titanate/carbon quantum dot composite material of the embodiment is used as a lithium ion battery cathode material, and has a first discharge specific capacity of 175.1mAh/g and a circulation capacity retention rate of 96.2% after 500 times under a current density of 875 mA/g.
Example 3
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate was dissolved in 50mL of an anhydrous ethanol/water mixed solvent, and stirred continuously for 1 hour, then filtered and baked at 80 ℃ for 3 hours to obtain titanium oxyhydroxide.
0.018g of titanium carbide powder was dispersed in 70mL of deionized water, and then 0.036g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (2) washing with absolute ethyl alcohol and deionized water for three times respectively to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining at the temperature rise rate of 2 ℃/min and the temperature of 550 ℃ for 6 hours to obtain the lithium titanate/carbon quantum dot composite material. Experiments prove that the content of the carbon quantum dots in the composite material is about 0.85wt%. The lithium titanate/carbon quantum dot composite material of the embodiment is used as a lithium ion battery cathode material, and has a first discharge specific capacity of 174.6mAh/g and a 500-time circulation capacity retention rate of 95.5% under a current density of 875 mA/g.
Example 4
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate are dissolved in 50mL of an anhydrous ethanol/water mixed solvent and stirred continuously for 1 hour, then filteredFiltering and baking at 80 ℃ for 3 hours to obtain the hydroxyl titanium oxide.
0.018g of titanium carbide powder was dispersed in 70mL of deionized water, and then 0.018g of cetyltrimethylammonium bromide and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (3) respectively washing the precursor with absolute ethyl alcohol and deionized water for three times to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining the precursor for 6 hours at 550 ℃ at the heating rate of 10 ℃/min to obtain the lithium titanate/carbon quantum dot composite material. Experiments prove that the content of the carbon quantum dots in the composite material is about 0.83wt%, the size of the carbon quantum dots is about 1nm, the thickness of the lithium titanate nano-sheets is about 10 mu m, and the micron meter rice size formed by the nano-sheets is about 1 mu m. The lithium titanate/carbon quantum dot composite material of the embodiment is used as a lithium ion battery cathode material, and has a first discharge specific capacity of 177.3mAh/g and a 500-time circulation capacity retention rate of 96.3% under a current density of 875 mA/g.
Example 5
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate was dissolved in 50mL of an anhydrous ethanol/water mixed solvent, and stirred continuously for 1 hour, then filtered and baked at 80 ℃ for 3 hours to obtain titanium oxyhydroxide.
0.09g of titanium carbide powder was dispersed in 70mL of deionized water, and then 0.024g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 150 ℃ for 14 hours. And (3) respectively washing the precursor with absolute ethyl alcohol and deionized water for three times to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining the precursor for 6 hours at 550 ℃ at the heating rate of 2 ℃/min to obtain the lithium titanate/carbon quantum dot composite material. Experiments prove that the content of the carbon quantum dots in the composite material is about 3wt%, the size of the carbon quantum dots is about 4nm, the thickness of the lithium titanate nanosheets is about 15nm, and the micrometer rice size formed by the nanosheets is about 5 micrometers. The lithium titanate/carbon quantum dot composite material of the embodiment is used as a lithium ion battery cathode material, and has a first discharge specific capacity of 175.8mAh/g and a circulation capacity retention rate of 96% after 500 times under a current density of 875 mA/g. When the lithium titanate/carbon quantum dot composite material is used as a magnesium ion battery anode material, the amount of the composite material Chu Meirong is as high as 192.2mAh/g under the current density of 100mA/g, and the capacity retention rate is 92.5% after 250 cycles.
Example 6
200mg of titanium aluminum carbide (Ti) 3 AlC 2 ) Adding the mixture into 20mL of hydrofluoric acid HF with the concentration of 48wt%, continuously stirring for 48 hours at 25 ℃, then filtering the mixture with deionized water for three times, and baking the mixture for 10 hours in a vacuum oven at 70 ℃ to obtain the titanium carbide powder with few layers. 2.382g of tetrabutyl titanate was dissolved in 50mL of an anhydrous ethanol/water mixed solvent, and stirred continuously for 1 hour, then filtered and baked at 80 ℃ for 3 hours to obtain titanium oxyhydroxide.
0.018g of titanium carbide powder was dispersed in 70mL of deionized water, and then 0.018g of sodium dodecylbenzenesulfonate and 0.587g of lithium hydroxide monohydrate were added and stirred for 30 minutes. 1.69g of titanium oxyhydroxide was weighed into the solution and stirred for 3 hours. Then, the solution was placed in a hydrothermal reaction kettle and reacted at 200 ℃ for 14 hours. And (3) respectively washing the precursor with absolute ethyl alcohol and deionized water for three times to obtain a precursor, then placing the precursor in a tubular furnace in an argon atmosphere, and calcining the precursor for 6 hours at 550 ℃ at the heating rate of 2 ℃/min to obtain the lithium titanate/carbon quantum dot composite material. Experiments prove that the content of the carbon quantum dots in the composite material is about 0.9wt%, the size of the carbon quantum dots is about 5nm, the thickness of the lithium titanate nano-sheets is about 20 microns, and the micron meter rice size formed by the nano-sheets is about 10 microns. The lithium titanate/carbon quantum dot composite material is used as a lithium ion battery cathode material, under the current density of 875mA/g, the first discharge specific capacity is up to 168.8mAh/g, and the circulation capacity retention rate is 94.2% after 500 times.
As can be seen from the above examples 1 to 6, the lithium titanate/carbon quantum dot composite materials described in examples 1 to 6 have superior capacity and cycle performance compared to the lithium titanate described in comparative example 1.
In summary, the invention provides a lithium titanate/carbon quantum dot composite material not easy to form an SEI film and a preparation method thereof. As the lithium titanate nanosheet is used as a main framework of the material, lithium titanate is not easy to react with electrolyte to form an SEI film, and the SEI film is not easy to generate in the use process of the material. In addition, the carbon quantum dots are embedded into the lithium titanate nano-sheets, so that the rapid transmission of electrons and ions is promoted, and the electrochemical performance of the lithium titanate composite material is improved.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims (10)
1. A preparation method of a lithium titanate/carbon quantum dot composite material is characterized by comprising the following steps:
step 1, preparing layered titanium carbide: mixing Ti 3 AlC 2 Placing the titanium carbide substrate in a hydrofluoric acid solution, stirring the titanium carbide substrate and the hydrofluoric acid solution for etching reaction to obtain layered titanium carbide;
step 2, preparing a lithium titanate/carbon quantum dot composite precursor: dispersing the layered titanium carbide, lithium hydroxide monohydrate, a surfactant and titanium oxyhydroxide in water, and carrying out hydrothermal reaction to obtain a lithium titanate/carbon quantum dot composite precursor; wherein, the mol ratio of the layered titanium carbide, the surfactant, the lithium hydroxide monohydrate and the hydroxyl titanium oxide is 1 (0.1-1): (25-150): 90-500);
step 3, preparing the lithium titanate/carbon quantum dot composite material: and calcining the lithium titanate/carbon quantum dot composite precursor in a protective atmosphere to obtain the lithium titanate/carbon quantum dot composite material.
2. The method according to claim 1, wherein the hydrofluoric acid solution is used in an amount of 30 to 50% by mass.
3. The method of claim 1, wherein the surfactant comprises: any one of polyvinylpyrrolidone, hexadecyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate, polyoxyethylene polypropylene ether block copolymer, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and polyethylene glycol octyl phenyl ether.
4. The preparation method according to claim 1, wherein the hydrothermal reaction in step 2 is carried out at a temperature of 140-200 ℃ for 10-24 hours.
5. The method of claim 1, wherein in the step 3, the calcination temperature is 500 to 700 ℃ and the temperature increase rate is 2 to 10 ℃/min.
6. The method according to claim 1, wherein in step 3, the protective atmosphere is Ar and N 2 At least one of (a).
7. The lithium titanate/carbon quantum dot composite material prepared by the preparation method according to any one of claims 1 to 6, which is characterized by comprising the following components in percentage by weight: the carbon quantum dots are uniformly embedded into the lithium titanate nanosheets.
8. The lithium titanate/carbon quantum dot composite material of claim 7, wherein the lithium titanate nanoplates have a thickness of 10-30nm.
9. A lithium ion battery comprising a positive electrode, a negative electrode and an electrolyte, wherein the negative electrode comprises the lithium titanate/carbon quantum dot composite material according to claim 7.
10. A magnesium ion battery, comprising a positive electrode, a negative electrode and an electrolyte, wherein the positive electrode comprises the lithium titanate/carbon quantum dot composite material according to claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211387276.0A CN115911307A (en) | 2022-11-07 | 2022-11-07 | Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211387276.0A CN115911307A (en) | 2022-11-07 | 2022-11-07 | Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115911307A true CN115911307A (en) | 2023-04-04 |
Family
ID=86491802
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211387276.0A Pending CN115911307A (en) | 2022-11-07 | 2022-11-07 | Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115911307A (en) |
-
2022
- 2022-11-07 CN CN202211387276.0A patent/CN115911307A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| YONG LI 等: "Ti3C2 MXene-derived Li4Ti5O12nanoplates with in-situ formed carbon quantum dots for metal-ion battery anodes", 《JOURNAL OF COLLOID AND INTERFACE SCIENCE》, vol. 629, 9 September 2022 (2022-09-09), pages 263 - 269 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108807926B (en) | Co/B Co-coated nickel-cobalt-manganese-lithium ion positive electrode material and preparation method thereof | |
| CN109659542B (en) | High-voltage lithium cobalt oxide cathode material with core-shell structure and preparation method thereof | |
| CN110668509B (en) | Selenium-coated high-nickel ternary layered positive electrode material and preparation method thereof | |
| CN108232147A (en) | Lithium ion battery high-nickel ternary positive electrode material with surface coated with lithium yttrium oxide and preparation method thereof | |
| WO2017000219A1 (en) | Doped conductive oxide and improved electrochemical energy storage device polar plate based on same | |
| KR100687672B1 (en) | Nonaqueous electrolyte secondary battery | |
| CN113363476B (en) | Ternary cathode material of lithium ion battery and preparation method thereof | |
| EP3836260A1 (en) | Negative electrode material, and preparation method therefor and use thereof | |
| CN106410153A (en) | Titanium nitride-cladded nickel titanate composite material as well as preparation method and application thereof | |
| CN111211305A (en) | PDA (personal digital Assistant) metal oxide coated high-nickel ternary layered positive electrode material and preparation method thereof | |
| CN112467138B (en) | Preparation method of aluminum-doped porous silicon-carbon composite material and lithium ion battery | |
| CN109546101A (en) | The preparation method and lithium ion battery of nickel cobalt lithium aluminate cathode material | |
| CN108400320B (en) | Method for vulcanizing surface of spinel lithium nickel manganese oxide positive electrode material | |
| CN113745504A (en) | Niobium-tungsten-titanium oxide negative electrode material and preparation method and application thereof | |
| CN106207113B (en) | A kind of carbon-coated LiFePO 4 for lithium ion batteries of Fluorin doped and its preparation method and application | |
| CN109742346B (en) | Si/Al co-coated nickel-cobalt-manganese lithium ion battery positive electrode material and preparation method thereof | |
| CN117334857B (en) | Sodium ion battery positive electrode material and preparation method thereof | |
| CN112234186B (en) | MXene nanodot coated modified lithium ion battery cathode material and preparation method thereof | |
| CN116706056A (en) | Based on ultra-small particles Na x Fe y M z (SO 4 ) 3 Non-destructive quick-charging positive electrode material, and preparation method and application thereof | |
| CN116845191A (en) | Self-supplementing lithium ternary material, preparation method and application | |
| CN115911307A (en) | Lithium titanate/carbon quantum dot composite material, preparation method thereof and battery | |
| CN111816873A (en) | Carbon-coated lithium manganese titanium phosphate composite material, preparation method thereof and application thereof in lithium ion battery | |
| CN110676450A (en) | Secondary battery anode material and battery thereof | |
| CN116247184B (en) | Nano lithium nickelate coated modified lithium manganate positive electrode material and preparation method and application thereof | |
| EP3930048A1 (en) | Positive electrode active material for lithium-ion secondary cell, and lithium-ion secondary cell |
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 |