Preparation method of manganese cobalt nitride negative electrode material, product and application

Abstract

The application discloses a preparation method of a manganese cobaltate negative electrode material, and a product and application thereof. Manganese salt and oxalic acid are dissolved in distilled water, which is marked as A; cobalt salt and oxalic acid are dispersed in an organic solvent, which is marked as B; A is slowly added into B to form C; ammonium fluoride is added into C to be stirred into a transparent solution; the transparent solution is transferred into a Teflon-lined autoclave, and heating, washing, filtering and vacuum drying are carried out to obtain a manganese cobaltate precursor; the manganese cobaltate precursor is calcined to obtain manganese cobaltate; and the manganese cobaltate is heated in an Ar / NH3 mixed atmosphere to obtain nitrogenated manganese cobaltate. The nitrogenated manganese cobaltate is used as a lithium battery negative electrode material, and under the condition of a current density of 500 mA / g, the first discharge specific capacity is 1560 mAh / g, the discharge specific capacity from the third time is 889 mAh / g, the discharge specific capacity from the 50th time is 822 mAh / g, and compared with the discharge specific capacity from the third time, the capacity retention rate is 92.5%.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a lithium battery negative electrode material, in particular to a preparation method of a cobalt-manganese nitride oxide negative electrode material, a product and application thereof. BACKGROUND

[0002] With the development of society, lithium ion batteries are paid more and more attention. The lithium ion battery is the most ideal rechargeable battery in the world at present, which has the advantages of large energy density, long cycle life, no memory effect and small pollution. With the progress of technology, the lithium ion battery will be widely applied in electric vehicles, aerospace and biological medicine fields, therefore, it is of great significance to research and develop the power lithium ion battery and related materials. For the power lithium ion battery, the key is to improve the power density and energy density, and the root of the improvement of the power density and energy density is the electrode material, especially the improvement of the negative electrode material.

[0003] Since the early 1990s, Japanese technology workers have developed a carbon material with a layered structure. The carbon material is the earliest material researched and applied to the commercialization of the lithium ion battery, and is still one of the focuses of attention and research. However, the carbon negative electrode material has some defects: when the battery is formed, the carbon negative electrode material reacts with the electrolyte to form an SEI film, which leads to the consumption of the electrolyte and low initial coulombic efficiency; when the battery is overcharged, lithium metal may be deposited on the surface of the carbon electrode to form lithium dendrites, which causes short circuit and leads to temperature rise and battery explosion; in addition, the diffusion coefficient of lithium ions in the carbon material is small, which leads to the fact that the battery cannot realize large-current charging and discharging, thereby limiting the application range of the lithium ion battery.

[0004] Mn2CoO4 is a composite oxide with a spinel structure, is a widely used magnetic material, is commonly used as a fuel cell material, and can also be used as a lithium ion battery negative electrode material at present. The material has a high Li+ storage capacity through conversion and alloying reaction. The material is considered as a promising lithium ion negative electrode material.

[0005] The application provides a preparation method of a cobalt-manganese nitride oxide negative electrode material. The cobalt-manganese nitride oxide negative electrode material is prepared by using a chemical solution method and argon / ammonia mixed atmosphere nitriding, the conductivity of the manganese cobalt oxide is improved through the nitriding treatment, and the electrochemical performance of the material is further improved. The preparation process is relatively simple and easy to operate. SUMMARY

[0006] In order to overcome the problem that the electrochemical performance of the existing manganese cobalt oxide is not high enough, the application aims to provide a preparation method of a cobalt-manganese nitride oxide negative electrode material.

[0007] A further object of the application is to provide a cobalt-manganese nitride oxide negative electrode material product obtained by the above method.

[0008] Still another object of the present application is to provide the use of the above product.

[0009] The present application is achieved by the following scheme: a preparation method of a manganese cobaltate negative material, characterized in that the manganese cobaltate negative material is prepared by a chemical solution method and nitrogenization in an argon / ammonia mixed atmosphere, and the specific steps of the method are as follows:

[0010] (1) 4 mmol of soluble manganese salt and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, and marked as solution A.

[0011] (2) 2 mmol of soluble cobalt salt and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent, and marked as solution B, and the A solution is slowly added to the B solution to form a C solution.

[0012] (3) 12 mmol of ammonium fluoride is added to the C solution, stirred for 100-150 min to become a transparent solution. Then, the solution C is transferred to a 100 mL Teflon-lined autoclave, heated at 160-180°C for 12-18 h, washed with ethanol for 3-5 times, filtered, and dried in a vacuum oven at 60-80°C for 10-20 h to obtain a manganese cobaltate precursor.

[0013] (4) The manganese cobaltate precursor is calcined in a tube furnace at 600-750°C, with a temperature rising rate of 2-5°C / min -1 for 4-8 h to obtain a manganese cobaltate.

[0014] (5) The manganese cobaltate is heated at 700-750°C for 1-1.5 h in an Ar / NH3 mixed atmosphere to obtain a manganese cobaltate nitride.

[0015] Preferably, in the step (1), the manganese salt is one or a combination of manganese acetate, manganese nitrate or manganese chloride.

[0016] Preferably, in the step (2), the cobalt salt is one or a combination of cobalt acetate, cobalt nitrate or cobalt chloride.

[0017] Preferably, in the step (2), the organic solvent is one or a combination of ethanol, methanol or propanol.

[0018] The present application provides a manganese cobaltate nitride negative material, which is prepared according to any of the above methods.

[0019] The present application provides the use of a manganese cobaltate nitride negative material in a lithium battery negative material.

[0020] The application provides a preparation method of a manganese cobaltate nitride negative electrode material.

[0021] The first discharge specific capacity is 1560 mAh / g under the condition of a current density of 500 mA / g, the third discharge specific capacity is 889 mAh / g, the 50th discharge specific capacity is 822 mAh / g, and the capacity retention rate is 92.5% compared with the third discharge specific capacity. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The cycle life chart of the manganese cobaltate nitride of Example 1. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be clearly and completely described in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0024] Example 1

[0025] A manganese cobaltate nitride negative electrode material is prepared by a chemical solution method and argon / ammonia mixed atmosphere nitriding, and is prepared according to the following steps:

[0026] (1) 4 mmol of soluble manganese acetate and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, and are marked as solution A;

[0027] (2) 2 mmol of soluble cobalt acetate and 6 mmol of oxalic acid are dispersed in 20 mL of an organic solvent ethanol, and are marked as solution B, the A solution is slowly added to the B solution to form a C solution;

[0028] (3) 12 mmol of ammonium fluoride is added to the C solution, and is stirred for 100 min to become a transparent solution; then, the transparent solution is transferred to a 100 mL Teflon-lined autoclave, is heated at 160 DEG C for 18 h, is washed with ethanol for 3 times, is filtered, and is dried in a vacuum oven at 80 DEG C for 10 h to obtain a manganese cobaltate precursor;

[0029] (4) the manganese cobaltate precursor is calcined at 600 DEG C for 8 h in a tube furnace with a heating rate of 2-5 DEG C / min -1 to obtain the manganese cobaltate;

[0030] (5) The manganese cobaltate is heated at 700 °C for 1.5 h under Ar / NH3 mixed atmosphere to obtain the manganese cobaltate nitride.

[0031] Figure 1 is the cycle life chart of the manganese cobaltate nitride. The first discharge specific capacity is 1560 mAh / g at a current density of 500 mA / g, the third discharge specific capacity is 889 mAh / g, and the 50th discharge specific capacity is 822 mAh / g. Compared with the third discharge specific capacity, the capacity retention rate is 92.5%.

[0032] Example 2

[0033] A manganese cobaltate nitride negative electrode material is prepared in the following steps, similar to Example 1:

[0034] (1) 4 mmol of soluble manganese nitrate and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A;

[0035] (2) 2 mmol of soluble cobalt chloride and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent methanol, marked as solution B, and the A solution is slowly added to the B solution to form a C solution;

[0036] (3) 12 mmol of ammonium fluoride is added to the C solution, stirred for 120 min to become a transparent solution; then, the transparent solution is transferred to a 100 mL Teflon-lined autoclave, heated at 180 °C for 12 h, washed with ethanol for 3 times, filtered, and dried in a vacuum oven at 60 °C for 20 h to obtain a manganese cobaltate precursor;

[0037] (4) The manganese cobaltate precursor is calcined in a tube furnace at 750 °C for 4 h with a temperature rising rate of 2 °C / min -1 to obtain the manganese cobaltate;

[0038] (5) The manganese cobaltate is heated at 750 °C for 1 h under Ar / NH3 mixed atmosphere to obtain the manganese cobaltate nitride.

[0039] Example 3

[0040] A manganese cobaltate nitride negative electrode material is prepared in the following steps, similar to Example 1:

[0041] (1) 4 mmol of soluble manganese chloride and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A;

[0042] (2) 2 mmol of soluble cobalt chloride and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent ethanol, marked as solution B, and the A solution is slowly added to the B solution to form a C solution;

[0043] (3) 12 mmol of ammonium fluoride was added to the C solution, stirred for 150 min to become a transparent solution; then, the transparent solution was transferred to a 100 mL Teflon-lined autoclave, heated at 180°C for 12 h, washed with ethanol for 3 times, filtered, and dried in a vacuum oven at 60°C for 20 h to obtain a manganese cobaltate precursor;

[0044] (4) The manganese cobaltate precursor was calcined in a tube furnace at 750°C for 6 h with a heating rate of 2°C / min -1 to obtain a manganese cobaltate;

[0045] (5) The manganese cobaltate was heated at 750°C for 1 h under Ar / NH3mixed atmosphere to obtain a nitrided manganese cobaltate.

Claims

1. A method for preparing a manganese cobalt nitride oxide negative electrode material, characterized by, A manganese cobaltate negative electrode material is prepared by a chemical solution method and nitriding in an argon / ammonia mixed atmosphere, including the following steps: (1) 4 mmol of soluble manganese salt and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A; (2) 2 mmol of soluble cobalt salt and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent, marked as solution B, the A solution is slowly added to the B solution to form C solution; (3) 12 mmol of ammonium fluoride is added to the C solution, stirred for 100-150 min to become a transparent solution; then, the solution C is transferred to a 100 mL Teflon-lined autoclave, heated at 160-180℃ for 12-18 h, washed with ethanol for 3-5 times, filtered, and dried in a vacuum oven at 60-80℃ for 10-20 h to obtain a manganese cobaltate precursor; (4) calcining the manganese cobaltate precursor in a tube furnace at 600-750 °C, at a temperature increase rate of 2-5 °C / min for 4-8 h to obtain manganese cobaltate; -1 (4) calcining the manganese cobaltate precursor in a tube furnace at 600-750 °C, at a temperature increase rate of 2-5 °C / min for 4-8 h to obtain manganese cobaltate; (5) the manganese cobaltate is heated at 700-750℃ for 1-1.5 h in an Ar / NH3 mixed atmosphere to obtain a manganese cobaltate nitride.

2. The method for preparing a manganese cobalt nitride anode material according to claim 1, characterized in that... The manganese salt is one or a combination of manganese acetate, manganese nitrate or manganese chloride.

3. The method for preparing a manganese cobalt nitride anode material according to claim 1, characterized in that... The cobalt salt is one or a combination of cobalt acetate, cobalt nitrate or cobalt chloride.

4. The method for preparing a manganese cobalt nitride anode material according to claim 1, characterized in that... The organic solvent is one or a combination of ethanol, methanol or propanol.

5. The method according to any one of claims 1 to 4, wherein the method is characterized in that The following steps are used for preparation: (1) 4 mmol of soluble manganese acetate and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A; (2) 2 mmol of soluble cobalt acetate and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent ethanol, marked as solution B, the A solution is slowly added to the B solution to form C solution; (3) 12 mmol of ammonium fluoride is added to the C solution, stirred for 100 min to become a transparent solution; then, the transparent solution is transferred to a 100 mL Teflon-lined autoclave, heated at 160℃ for 18 h, washed with ethanol for 3 times, filtered, and dried in a vacuum oven at 80℃ for 10 h to obtain a manganese cobaltate precursor; (4) The manganese cobaltate precursor is calcined in a tube furnace at a heating rate of 2-5 ℃ / min -1 , 600 ℃ for 8 h to obtain manganese cobaltate. (5) the manganese cobaltate is heated at 700℃ for 1.5 h in an Ar / NH3 mixed atmosphere to obtain a manganese cobaltate nitride.

6. The method according to any one of claims 1 to 4, wherein the method is characterized in that The following steps are used for preparation: (1) 4 mmol of soluble manganese nitrate and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A; (2) 2 mmol of soluble cobalt nitrate and 6 mmol of oxalic acid are dispersed in 20 mL of organic solvent methanol, marked as solution B, the A solution is slowly added to the B solution to form C solution; (3) 12 mmol of ammonium fluoride is added to the C solution, stirred for 120 min to become a transparent solution; then, the transparent solution is transferred to a 100 mL Teflon-lined autoclave, heated at 180℃ for 12 h, washed with ethanol for 3 times, filtered, and dried in a vacuum oven at 60℃ for 20 h to obtain a manganese cobaltate precursor; (4) The manganese cobaltate precursor is calcined in a tube furnace at 750 °C, a heating rate of 2 °C / min, and for 4 h to obtain manganese cobaltate; -1 (4) The manganese cobaltate precursor is calcined in a tube furnace at 750 °C, a heating rate of 2 °C / min, and for 4 h to obtain manganese cobaltate; (5) the manganese cobaltate is heated at 750℃ for 1 h in an Ar / NH3 mixed atmosphere to obtain a manganese cobaltate nitride.

7. The method according to any one of claims 1 to 4, wherein the method is characterized by The following steps are used for preparation: (1) 4 mmol of soluble manganese chloride and 16 mmol of oxalic acid are dissolved in 50 mL of distilled water, marked as solution A; (2) 2 mmol soluble cobalt chloride and 6 mmol oxalic acid were dispersed in 20 mL of organic solvent ethanol, marked as solution B, the A solution was slowly added to the B solution to form a C solution; (3) 12 mmol of ammonium fluoride was added to the C solution, stirred for 150 min to become a transparent solution; then, the transparent solution was transferred to a 100 mL Teflon-lined autoclave, heated at 180°C for 12 h, washed with ethanol for 3 times, filtered, and dried in a vacuum oven at 60°C for 20 h to obtain a manganese cobaltate precursor; (4) The manganese cobaltate precursor is calcined in a tube furnace at 750 °C, a heating rate of 2 °C / min, and for 6 h to obtain manganese cobaltate; -1 (4) The manganese cobaltate precursor is calcined in a tube furnace at 750 °C, a heating rate of 2 °C / min, and for 6 h to obtain manganese cobaltate; (5) the manganese cobaltate was heated at 750°C for 1 h under Ar / NH3 mixed atmosphere to obtain a nitrogenated manganese cobaltate.

8. A manganese cobalt nitride oxide negative electrode material characterized by Prepared according to any one of the methods of claims 1-7.

9. Use of the nitrogenated manganese cobaltate anode material of claim 8 in a lithium battery anode material.

Images