阅读说明：本技术 无序岩盐结构的正极材料Li1.3Mo0.3V0.4O2的合成方法 (Cathode material Li with disordered rock salt structure1.3Mo0.3V0.4O2Method of synthesis of ) 是由 陈泽华 陈林 王秋芬 邢宝林 张传祥 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种无序岩盐结构的正极材料Li-(1.3)Mo-(0.3)V-(0.4)O-2的合成方法,具体有以下几个步骤：称取醋酸锂、乙酸钼和乙酰丙酮氧钒放入球磨机进行球磨；取出球磨后的粉末加入到乙二醇溶液中；混合溶液进行水浴加热的同时采用磁力搅拌,直至形成流变相；之后放入烘箱中干燥得到前驱体；将前驱体放入微波烧结炉进行烧结,并通入氧气,自然冷却,充分研磨,即得到目标产物。本发明先采用流变相法将原料制成糊状的流变状态,并加入乙二醇,利用其优越的配位能力与金属离子进行螯合,固体颗粒能够均匀分散,此方法操作简单且物料混合均匀,最后再结合微波烧结对前驱体进行处理,显著提高加热效率,改善被烧结材料的微观结构和性能。(The invention discloses a cathode material Li with a disordered rock salt structure 1.3 Mo 0.3 V 0.4 O 2 The synthesis method specifically comprises the following steps: weighing lithium acetate, molybdenum acetate and vanadyl acetylacetonate, and putting into a ball mill for ball milling; taking out the powder after ball milling and adding the powder into glycol solution; heating the mixed solution in water bath while magnetically stirring until a rheological phase is formed; then putting the precursor into an oven to be dried to obtain a precursor; and sintering the precursor in a microwave sintering furnace, introducing oxygen, naturally cooling, and fully grinding to obtain the target product. The invention firstly adopts the rheological phase method to prepare the raw materials into pasteThe method is simple to operate, materials are uniformly mixed, and finally the precursor is treated by combining with microwave sintering, so that the heating efficiency is remarkably improved, and the microstructure and the performance of the sintered material are improved.)

1. Cathode material Li with disordered rock salt structure_1.3Mo_0.3V_0.4O₂The synthesis method is characterized by comprising the following steps:

(1) weighing lithium acetate, molybdenum acetate and vanadyl acetylacetonate, and putting into a ball mill for ball milling;

(2) taking out the powder subjected to ball milling in the step (1), and adding the powder into an ethylene glycol solution to obtain a mixed solution;

(3) heating the mixed solution obtained in the step (2) in a water bath, simultaneously stirring by adopting magnetic force to form a rheological phase, and then drying in an oven to obtain a precursor;

(4) sintering the precursor obtained in the step (3) in a microwave sintering furnace, introducing oxygen, naturally cooling, and fully grinding to obtain the anode material Li with the metahalite structure_1.3Mo_0.3V_0.4O₂。

2. The disordered rock salt structure positive electrode material Li according to claim 1_1.3Mo_0.3V_0.4O₂The synthesis method is characterized in that: in the step (1), the molar ratio of the lithium acetate to the molybdenum acetate to the vanadyl acetylacetonate is 13:3: 4.

3. The disordered rock salt structure positive electrode material Li according to claim 1_1.3Mo_0.3V_0.4O₂The synthesis method is characterized in that: in the step (1), the rotating speed of the ball mill is 400-600 r/min, and the time is 1-2 h.

4. The disordered rock salt structure positive electrode material Li according to claim 1_1.3Mo_0.3V_0.4O₂The synthesis method is characterized in that: in the step (2), the concentration of the ethylene glycol solution is 1 mol/L.

5. The disordered rock salt structure positive electrode material Li according to claim 1_1.3Mo_0.3V_0.4O₂The synthesis method is characterized in that: in the step (3), the rotating speed of the magnetic stirring is 200-300rpm, 60-80 ℃ of water bath heating, 100-120 ℃ of drying temperature and 8-10 hours of drying time.

6. The disordered rock salt structure positive electrode material Li according to claim 1_1.3Mo_0.3V_0.4O₂The synthesis method is characterized in that: in the step (4), the temperature rise rate during sintering is 3-5 ℃/min, and sintering is carried out for 8-12 h at 700-900 ℃.

Technical Field

The invention belongs to the technical field of lithium ion battery anode materials, and particularly relates to an anode material Li with a disordered rock salt structure_1.3Mo_0.3V_0.4O₂The method of (1).

Background

With the use of traditional energy, serious environmental pollution is generated, and with the consumption of non-renewable resources, research and development of novel energy sources and energy storage technologies are urgently needed to reduce the emission of carbon dioxide. Low carbon will depend on lithium ion batteries, an indispensable technology in the future. Lithium ion batteries have been widely used in notebook computers and smart phones and will become the core energy storage material in future electric vehicles and many other fields.

At present, lithium ion battery anode materials widely used in the market mainly comprise ternary materials such as lithium cobaltate, lithium manganate, lithium iron phosphate, nickel cobalt manganese and the like, and although the ternary materials have certain advantages, each material also has the problem which cannot be avoided. The lithium cobaltate and the nickel-cobalt-manganese ternary material both have noble metal cobalt, so that the cost is increased and the metal cobalt has toxicity. Lithium cobaltate still needs to be improved in safety performance, and the lithium iron phosphate battery has low energy density, poor low-temperature performance and low tap density, so that the lithium iron phosphate battery has no competitive advantage in small products. Although lithium manganate is the most promising environment-friendly electrode material in the current lithium ion batteries, the lithium manganate also has the problems of poor cycle performance, rapid high-temperature capacity attenuation and the like.

As a key factor limiting the capacity of lithium ion batteries, various methods have been used to synthesize a positive electrode material, among which a coprecipitation method and a solid phase method are currently the most commonly used methods, and in addition, a sol-gel method, a spray pyrolysis method, an emulsion method, and a molten salt method are widely used. The solid phase method has simple operation process, but the product has the problems of non-uniform phase, large grain boundary size and the like, thereby influencing the performance of the material. Compared with the solid phase method, the liquid phase synthesis methods adopting the sol-gel method have the advantages that the prepared product has uniform phase and uniform granularity, but the parameters need to be strictly controlled in the preparation process, the operation is complex, and the method is not beneficial to industrial popularization. Therefore, a simple and feasible synthesis method capable of preparing a small-particle-size anode material is sought to improve the performance of the anode material.

Disclosure of Invention

Aiming at the defects, the invention provides the anode material Li with the disordered rock salt structure_1.3Mo_0.3V_0.4O₂The method successfully prepares the anode material Li with the disordered rock salt structure_1.3Mo_0.3V_0.4O₂The cycle performance of the material is obviously improved.

In order to solve the technical problems, the invention adopts the following technical scheme:

cathode material Li with disordered rock salt structure_1.3Mo_0.3V_0.4O₂The synthesis method is characterized by comprising the following steps:

(1) weighing lithium acetate (CH)₃COOLi•2H₂O), molybdenum acetate (C)₈H₁₂Mo₂O₈) And vanadyl (C) acetylacetonate₁₀H₁₄O₅V) putting the mixture into a ball mill for ball milling;

(2) taking out the powder subjected to ball milling in the step (1), and adding the powder into an ethylene glycol solution to obtain a mixed solution;

(3) heating the mixed solution obtained in the step (2) in a water bath, simultaneously stirring by adopting magnetic force to form a rheological phase, and then drying in an oven to obtain a precursor;

(4) sintering the precursor obtained in the step (3) in a microwave sintering furnace, introducing oxygen, naturally cooling, and fully grinding to obtain the anode material Li with the metahalite structure_1.3Mo_0.3V_0.4O₂。

Further, in the step (1), the molar ratio of the lithium acetate to the molybdenum acetate to the vanadyl acetylacetonate is 13:3: 4.

Further, in the step (1), the rotating speed of the ball mill is 400-600 r/min, and the time is 1-2 h.

Further, in the step (2), the concentration of the ethylene glycol solution is 1mol/L, and the volume is 100 mL.

Further, in the step (3), the rotating speed of magnetic stirring is 200-300 rpm, the temperature of water bath heating is 60-80 ℃, the drying temperature is 100-120 ℃, and the time is 8-10 hours.

Further, in the step (4), the temperature rise rate during sintering is 3-5 ℃/min, and sintering is carried out for 8-12 h at 700-900 ℃.

The invention has the beneficial effects that: the invention firstly adopts the rheological phase method to prepare the raw materials into a pasty rheological state, and adds the organic alcohol-glycol, and chelates with metal ions by utilizing the excellent coordination capability of the organic alcohol-glycol, so that solid particles can be uniformly dispersed.

Drawings

FIG. 1 shows Li prepared in example 1 of the present invention_1.3Mo_0.3V_0.4O₂SEM image of (d).

FIG. 2 shows Li prepared in example 1 of the present invention_1.3Mo_0.3V_0.4O₂Cycle performance map of (c).

FIG. 3 shows Li prepared in example 1 of the present invention_1.3Mo_0.3V_0.4O₂Graph of charge and discharge at a current density of 10 mA/g.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited to the following.

Example 1

Cathode material Li with disordered rock salt structure_1.3Mo_0.3V_0.4O₂The synthesis method comprises the following specific steps:

(1) weighing 6.6313g (0.065 mol) of lithium acetate, 3.2104g (0.0075 mol) of molybdenum acetate and 5.3030g (0.02 mol) of acetylacetonato vanadyl, putting into a ball mill, and carrying out ball milling for 2h at the speed of 500 r/min;

(2) taking out the powder subjected to ball milling and adding the powder into 1 mol/L100 mL of glycol solution;

(3) heating the mixed solution in water bath at 80 ℃, and forming a rheological phase at the rotating speed of 300rpm by magnetic stirring;

(4) then putting the precursor into an oven, and drying the precursor for 8 hours at the temperature of 120 ℃ to obtain a precursor;

(5) and (3) putting the precursor into a microwave sintering furnace, heating to 850 ℃ at the speed of 3 ℃/min, sintering for 10h, introducing oxygen, naturally cooling, and fully grinding to obtain the target product.

FIG. 1 shows a positive electrode material Li prepared by the present invention_1.3Mo_0.3V_0.4O₂The prepared material has a nano scale and good porosity, more channels are provided for the insertion and extraction of lithium ions, the particles do not have an agglomeration phenomenon, and the crystal form is good.

FIG. 2 shows the Li anode material prepared by the invention_1.3Mo_0.3V_0.4O₂The initial charging capacity can reach 348mAh/g, the initial discharging capacity is 249mAh/g, and the capacity is 138mAh/g after 40 times of circulation.

FIG. 3 shows the Li anode material prepared by the invention_1.3Mo_0.3V_0.4O₂According to a charge-discharge curve diagram under the current density of 10mA/g, the maximum specific discharge capacity is close to 400mAh/g, the battery is charged and discharged for many times in a voltage range of 1.5V-4.5V, and the capacity of the battery is still higher than 350 mAh/g.

Example 2

Cathode material Li with disordered rock salt structure_1.3Mo_0.3V_0.4O₂The synthesis method comprises the following specific steps:

(1) weighing 2.6525g (0.026 mol) of lithium acetate, 1.2842g (0.003 mol) of molybdenum acetate and 2.1212g (0.008 mol) of acetylacetonato vanadyl, putting into a ball mill, and ball-milling at the speed of 400r/min for 2 h;

(2) taking out the powder subjected to ball milling and adding the powder into 1 mol/L100 mL of glycol solution;

(3) heating the mixed solution in water bath at 60 ℃, and forming a rheological phase at the rotating speed of 200rpm by magnetic stirring;

(4) then putting the precursor into an oven, and drying the precursor for 8 hours at the temperature of 120 ℃ to obtain a precursor;

(5) and (3) putting the precursor into a microwave sintering furnace, heating to 750 ℃ at the speed of 5 ℃/min, sintering for 12h, introducing oxygen, naturally cooling, and fully grinding to obtain the target product.

Example 3

Cathode material Li with disordered rock salt structure_1.3Mo_0.3V_0.4O₂The synthesis method comprises the following specific steps:

(1) weighing 2.6525g (0.026 mol) of lithium acetate, 1.2842g (0.003 mol) of molybdenum acetate and 2.1212g (0.008 mol) of acetylacetonato vanadyl, putting into a ball mill, and ball-milling at the speed of 600r/min for 2 h;

(2) taking out the powder subjected to ball milling and adding the powder into 1 mol/L100 mL of glycol solution;

(3) heating the mixed solution in water bath at 60 ℃, and forming a rheological phase at the rotating speed of 200rpm by magnetic stirring;

(4) then putting the mixture into an oven, and drying the mixture for 10 hours at 120 ℃ to obtain a precursor;

(5) and (3) putting the precursor into a microwave sintering furnace, heating to 800 ℃ at the speed of 3 ℃/min, sintering for 10h, introducing oxygen, naturally cooling, and fully grinding to obtain the target product.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.