阅读说明：本技术 一种乒乓菊形貌钒酸锂材料的制备方法 (Preparation method of ping-pong chrysanthemum-shaped lithium vanadate material ) 是由 冯莉莉 张威 于 2019-11-05 设计创作，主要内容包括：本发明公开了一种乒乓菊形貌钒酸锂材料的制备方法,本发明利用无毒性的乙酰丙酮氧钒作为钒源,采用乙醇作为溶剂制备前驱体溶液；将制备的前驱体溶液进行水热反应处理后再与含锂化合物进行高温焙烧,最终获得直径为250-500nm以及4-5μm的兵乓菊形貌的钒酸锂材料,该材料可作为传统锂离子电池正极使用,也是水系锂离子电池负极的优良材料。(The invention discloses a preparation method of a lithium vanadate material with a shape of a table tennis chrysanthemum, which is characterized in that nontoxic vanadyl acetylacetonate is used as a vanadium source, and ethanol is used as a solvent to prepare a precursor solution; the prepared precursor solution is subjected to hydrothermal reaction treatment and then is subjected to high-temperature roasting with a lithium-containing compound, and finally the lithium vanadate material with the diameter of 250-500nm and the morphology of 4-5 mu m, namely the shape of the Bing-pong chrysanthemum, can be used as the anode of the traditional lithium ion battery and is also an excellent material of the cathode of the water system lithium ion battery.)

1. A preparation method of a table tennis chrysanthemum morphology lithium vanadate material is characterized by comprising the following steps:

s1, adding vanadyl acetylacetonate into an ethanol solvent, and uniformly stirring to obtain a precursor solution, wherein the concentration of vanadyl acetylacetonate in the precursor solution is 1mmol L ^-1～67mmol L ^-1；

S2, carrying out hydrothermal reaction on the precursor solution prepared in the step S1 at the temperature of 150 ℃ and 220 ℃ for 12-48h, and naturally cooling to room temperature after the reaction is finished;

s3, performing centrifugal separation on the precursor solution after the hydrothermal reaction is cooled, washing the obtained solid substance by using deionized water, and drying to obtain a lithium vanadate material intermediate;

s4, grinding and mixing the lithium vanadate material intermediate and a lithium-containing compound, and sintering the mixture in an air atmosphere at the temperature of 300-500 ℃ for 3-15h to obtain the lithium vanadate material with the shape of a Ping-Pong chrysanthemum, wherein the mass ratio of the lithium vanadate material intermediate to a lithium element substance in the lithium-containing compound is 1: 1-1.3.

2. The preparation method of the lithium vanadate material with the shape of table tennis chrysanthemum according to claim 1, wherein the preparation method is characterized in thatAdding oxalic acid as a regulator into the ethanol solvent in the step S1, and then adding vanadyl acetylacetonate, wherein the concentration range of the oxalic acid in the precursor solution is 0.01-0.75mol L ^-1。

3. The method for preparing a lithium vanadate material with a shape like a table tennis chrysanthemum according to claim 1, wherein the lithium-containing compound in the step S4 is LiOH, LiCl or LiNO ₃、Li ₂CO ₃、Li ₂One or more of O, lithium acetate, lithium formate and lithium citrate.

4. The preparation method of a lithium vanadate material with a shape like a ping-pong chrysanthemum according to claim 1, wherein the mass ratio of the solid matter of the intermediate of the lithium vanadate material dried in the step S3 to the lithium-containing compound is 1: 1.15-1.2.

Technical Field

The invention relates to the technical field of lithium vanadate materials, in particular to a preparation method of a lithium vanadate material with a shape of solidago and pong chrysanthemum.

Background

Vanadium oxide (V) ₂O ₅，VO ₂，V ₂O ₃，LiV ₃O ₈Etc.) have received much attention in recent years as energy storage materials, among which lithium vanadate (LiV) ₃O ₈) The lithium ion battery anode material has high theoretical specific capacity, long cycle life and structural stability relative to other vanadium compounds, and is considered to be an ideal anode material of the lithium ion battery. LiV ₃O ₈Can contain three Li ⁺The ions are inserted and extracted, and more than 280mAh g is released ^-1The capacity of (c). LiV ₃O ₈Belonging to the monoclinic system, each unit cell is composed ofTwo LiV ₃O ₈Molecular composition containing both two octahedral sites and six tetrahedral sites for Li ⁺And (4) occupation. LiV ₃O ₈Is a Li-poor material, Li pre-existing in the structure ⁺The material exists in the octahedron position in the structure, plays a role in charge balance and cannot be separated in the circulation process; intercalated Li ⁺Then there are positions of tetrahedra between the layers. This results in a stable crystal structure of the material during charge and discharge cycles, and a large number of oxygen tetrahedral vacancies in the material can be used for reversible intercalation and deintercalation of lithium ions. Each lithium vanadate unit can reversibly intercalate more than 3 lithium ions, and in multiple cycles, LiV ₃O ₈And a stable crystal structure can be maintained, and excellent electrochemical performance is shown. At the same time due to LiV ₃O ₈The lithium ion battery cathode material has unique potential advantages and can be used as a cathode material of a water system lithium ion battery. Compared with the traditional lithium ion battery, the water-based battery has the advantages that the water-based battery can be assembled without using an expensive anhydrous oxygen-free glove box, the assembly process requirement of the lithium ion battery is reduced, and the production cost of the battery can be effectively reduced.

In various studies, to improve LiV ₃O ₈The electrical property of the material has cyclic stability, the specific capacity of the battery is inhibited from being attenuated, and the LiV is improved ₃O ₈One of the most effective methods is to construct nanostructures such as nanowires, nanosheets, nanobelts, nanorods, etc. In patent CN201910002293, liubo et al prepared LiV by solution combustion method ₃O ₈A material. Heating and igniting a mixed system of lithium nitrate solution, fuel and ammonium metavanadate, burning to obtain fluffy foam powder after the burning is finished, and then carrying out heat treatment on the fluffy foam powder at 400-600 ℃ to obtain LiV ₃O ₈And (4) powder particles. In patent CN201410418586, vanadium pentoxide and a lithium source are uniformly mixed by a gel sol method by means of a chenqiang and the like, and then a proper amount of water is added to prepare a turbid liquid; then, dropwise adding a chelating agent into the turbid liquid to obtain a clear solution; and finally, drying, presintering and calcining the clarified solution to obtain the lithium vanadate serving as the lithium ion battery material. In thatApplication V of patent CN201210395293 Pananqiang and the like ₂O ₅、NH ₄VO ₃And HVO ₃Stirring a vanadium source and a reducing organic acid in a solution according to a certain stoichiometric ratio to obtain a solution which is blue, sequentially adding a lithium source (the molar ratio of lithium to vanadium is Li: V ═ 1:3), a surfactant, an Ag-containing compound and N, N-dimethylformamide, fully stirring, drying to obtain a blue solid sol, and heating at the temperature of 450-600 ℃ in an oxidizing atmosphere to obtain LiV ₃O ₈Ag nano belt. Therefore, lithium vanadate nano materials with different morphological characteristics have obviously different chemical properties.

Disclosure of Invention

Based on the above, the invention aims to provide a preparation method of a lithium vanadate material with a shape of solidago virescens. The lithium vanadate material is prepared by preparing a material intermediate through a hydrothermal method, mixing the material intermediate with a lithium-containing compound and calcining the mixture. The invention prepares the lithium vanadate material with the shape of the table tennis chrysanthemum by regulating and controlling parameters in the reaction process.

The preparation method of the lithium vanadate material with the morphology of the penny chrysanthemum comprises the following steps:

s1, adding vanadyl acetylacetonate into an ethanol solvent, and uniformly stirring to obtain a precursor solution, wherein the concentration of vanadyl acetylacetonate in the precursor solution is 1mmol L ^-1～67mmol L ^-1；

S2, carrying out hydrothermal reaction on the precursor solution prepared in the step S1 at the temperature of 150 ℃ and 220 ℃ for 12-48h, and naturally cooling to room temperature after the reaction is finished;

s3, performing centrifugal separation on the precursor solution after the hydrothermal reaction is cooled, washing the obtained solid substance by using deionized water, and performing drying treatment, wherein the drying mode can be vacuum drying, freeze drying or drying by using a blast drying oven, so as to obtain a lithium vanadate material intermediate;

s4, grinding and mixing the lithium vanadate material intermediate and a lithium-containing compound, and sintering the mixture in an air atmosphere at the temperature of 300-500 ℃ for 3-15h to obtain the lithium vanadate material with the shape of a Ping-Pong chrysanthemum, wherein the mass ratio of the lithium vanadate material intermediate to a lithium element substance in the lithium-containing compound is 1: 1-1.3.

Preferably, oxalic acid is further added into the ethanol solvent of step S1 as a regulator, and then vanadyl acetylacetonate is further added, wherein the concentration range of oxalic acid in the precursor solution is 0.01-0.75mol L ^-1。

Preferably, the lithium-containing compound in step S4 is LiOH, LiCl, LiNO ₃、Li ₂CO ₃、Li ₂One or more of O, lithium acetate, lithium formate and lithium citrate.

Preferably, the mass ratio of the solid material dried in step S3 to the lithium-containing compound is 1: 1.15-1.2.

Compared with the prior art, the invention has the following beneficial effects: the invention uses non-toxic vanadyl acetylacetonate as a vanadium source and ethanol as a solvent to prepare a precursor solution; the prepared precursor solution is subjected to hydrothermal reaction treatment and then is subjected to high-temperature roasting with a lithium-containing compound, and finally the lithium vanadate material with the diameter range of 250-500nm is obtained.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is an SEM image of a ping-pong chrysanthemum morphology lithium vanadate material prepared in example 1 of the invention;

FIG. 2 is an XRD diagram of a lithium vanadate material with a shape of a table tennis chrysanthemum prepared in example 1 of the invention;

FIG. 3 is an SEM image of a ping-pong chrysanthemum morphology lithium vanadate material prepared in example 2 of the invention;

fig. 4 is a charge-discharge curve diagram of a lithium ion battery manufactured by using the lithium vanadate material prepared in example 1 of the present invention as a positive electrode.

Detailed Description

The invention is further described with reference to the following specific embodiments and the accompanying drawings.