CN107311119A - Hollow nanoprisms material of the cobalt nickel of four selenizing two and its preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of nanomaterials and electrochemistry, and in particular relates to a nickel dicobalt selenide hollow nano-prism material and a preparation method thereof. The material can be used as a high-capacity and long-life lithium-ion or sodium-ion battery negative electrode active material. It includes the following steps: 1) Weighing 125 mg of nickel-cobalt precursor and 0.111 g of selenium dioxide powder, dissolving them in 35 ml of benzyl alcohol solution, and fully stirring at room temperature; 2) transferring the solution obtained in step 1) to a reaction kettle, Heating to carry out solvothermal reaction; 3) centrifuging the product obtained in step 3), washing the obtained precipitate repeatedly, and drying. When the invention is used as the active material of the negative electrode material of the lithium-ion battery, the hollow nano-prism material exhibits excellent cycle stability and high capacity, and is a potential application material of the high-power and long-life sodium-ion battery.

Description

Nickel dicobalt selenide hollow nano prism material and its preparation method and application

technical field

The invention belongs to the technical field of nanomaterials and electrochemistry, and in particular relates to a nickel dicobalt selenide hollow nano-prism material and a preparation method thereof. The material can be used as a high-capacity and long-life lithium-ion or sodium-ion battery negative electrode active material.

Background technique

With the rapid growth of the global economy and population, environmental pollution and excessive consumption of fossil energy make people's demand for green energy is increasing day by day. Lithium-ion batteries have been widely used in portable devices such as mobile phones, digital cameras, and notebook computers due to their high energy density and long cycle life. At present, as the negative electrode material of commercialized lithium-ion batteries, the theoretical capacity of graphite is low, and the lower capacity has become a limit to the application of lithium-ion batteries in hybrid electric vehicles and pure electric vehicles. Therefore, the development of high-capacity long-term Long-lasting lithium-ion battery anode materials are one of the frontiers and hotspots of lithium-ion battery research in the era of environment-friendly, resource-saving and low-carbon economy. Due to their small size, large specific surface area, and high activity, nanomaterials are fully in contact with the electrolyte when used as electrode materials for lithium-ion batteries, and the de-intercalation distance of lithium ions and electrons is short and fast. Advantage.

Contents of the invention

The technical problem to be solved by the present invention is to propose a hollow nano-prism material of nickel dicobalt selenide and a preparation method thereof for the above-mentioned prior art. electrochemical performance.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: a hollow nano-prism material of dicobalt-nickel tetraselenide, which has a hollow structure, and the nano-prism is 1-1.5 microns long and 150-250 nanometers wide.

The preparation method of the nickel dicobalt selenide hollow nano-prism material is characterized in that it comprises the following steps:

1) Weigh 125mg of nickel-cobalt precursor and 0.111g of selenium dioxide powder, dissolve in 35ml of benzyl alcohol solution, and stir fully at room temperature;

2) transfer the solution obtained in step 1) to a reaction kettle, and heat to carry out solvothermal reaction;

3) The product obtained in step 3) is centrifugally filtered, the obtained precipitate is repeatedly washed, and dried.

According to the above scheme, the preparation method of the described nickel-cobalt precursor is:

a) Measure 5g of polyvinylpyrrolidone PVP powder, mix 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder with a mass ratio of 1:2, dissolve in an organic solution, and stir fully at room temperature;

b) heating the solution obtained in step a) under the device of condensing and refluxing;

c) centrifuging the product obtained in step b), washing the obtained precipitate, and drying to obtain a nickel-cobalt precursor.

According to the above scheme, the polyvinylpyrrolidone PVP is PVP-K13, PVP-K17 or PVP-K30, wherein the MW of the PVP-K13 and PVP-K17 is ~10000.

According to the above scheme, the reaction temperature in step b) is 80-90° C., and the reaction time is 3-6 hours.

According to the above scheme, the reaction temperature in step 2) is 120-160° C., and the reaction time is 8-24 hours.

The application of the nickel dicobalt selenide hollow nano prism material as the negative electrode active material of lithium ion or sodium ion battery.

The hollow nanoprisms of the present invention exhibit many advantages in energy storage applications due to their novel and unique electrochemical and structural characteristics. In lithium-ion batteries, the hollow structure provides an effective barrier for the volume expansion of electrode materials during charge-discharge cycles. The buffer space slows down the collapse and cracking of the structure, thereby improving the cycle stability and cycle life of the electrode material. Therefore, the hollow nano-prism structure is very suitable for application in lithium-ion battery electrode materials.

The invention utilizes the steric effect of cobalt-nickel tetraselenide hollow nano-prism material and its good mechanical properties and thermal stability, utilizes the hollow structure to buffer the volume expansion brought about in the process of charging and discharging, and improves the cycle stability and capacity of the material, etc. electrochemical performance.

The beneficial effect of the present invention is: based on the Kirkendall effect, the shape of the hollow nano-prism is skillfully designed, and the hollow nano-prism material of nickel dicobalt selenide is obtained through a simple solvothermal method. When the present invention is used as the active material of the negative electrode material of lithium ion battery, the hollow nano prism material shows excellent cycle stability and high capacity, and is a potential application material of high power and long life sodium ion battery, as the negative electrode of lithium ion battery As an active material, the initial capacity can reach 2011mAh g ^-1 at a current density of 100mA g ^-1 , the capacity can still reach 1200mAh g ^-1 after 30 cycles, and the initial capacity can still be achieved at a high current density of 2000mA g ^-1 It can reach 1110mAh g ^-1 , and the discharge capacity can still reach 600mAh g ^-1 after 400 cycles. The process of the invention is simple, and the simple solvothermal method adopted has low equipment requirements, which can be achieved by changing the concentration of reactants, reaction temperature and time The shape and size of the material are controlled, and the prepared material has high purity and good dispersibility, and is easy to expand industrial production, which is very conducive to market promotion.

Description of drawings

Fig. 1 is the XRD figure of the hollow nickel dicobalt selenide nano-prism material of embodiment 1 of the present invention;

Fig. 2 is the scanning electron microscope picture of the hollow nickel dicobalt selenide nano-prism material of embodiment 1 of the present invention;

Fig. 3 is the transmission electron micrograph of the hollow nickel dicobalt selenide nano-prism material of embodiment 1 of the present invention;

Fig. 4 is the battery cycle performance graph of the hollow nickel dicobalt selenide nano-prism material in Example 1 of the present invention at a current density of 100mA g ^-1 ;

Fig. 5 is the battery cycle performance graph of the hollow nickel dicobalt selenide nano-prism material in Example 1 of the present invention at a current density of 2000mA g ^-1 ;

Fig. 6 is a transmission electron microscope image of the hollow nickel dicobalt selenide nanosphere material of Example 6 of the present invention.

detailed description

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

Example 1:

A method for preparing a hollow cobalt-nickel tetraselenide nano-prism material, comprising the steps of:

1) Measure 5g of polyvinylpyrrolidone PVP-K17 powder (MW～10000), 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) and dissolve them in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 85° C. for 4 hours in an oil bath under the device of condensation and reflux;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 70°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4) and 0.111 g of selenium dioxide powder, dissolve it in 35 ml of benzyl alcohol solution, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 160° C. for 12 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 70°C;

Taking the cobalt-nickel tetraselenide hollow nano-prism material of this example as an example, its structure is determined by an X-ray diffractometer, as shown in Figure 1, and the X-ray diffraction pattern (XRD) shows that there is no other impurity phase. As shown in FIG. 2 , the field emission scanning electron microscope (FESEM) test shows that the material is a hollow nano-prism material, and the hollow nano-prism has a length of 1-1.5 micrometers and a width of 150-250 nanometers. As shown in FIG. 3 , transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) tests show that the nanostructure is a hollow structure and has a good crystal structure. The process of the invention is due to the synergistic effect of the surfactant and the reducing agent (PVP and benzyl alcohol) and the Kirkendall effect to form a hollow nickel dicobalt selenide nanometer prism material.

The nickel dicobalt selenide hollow nano-prism material prepared in this example is used as the negative electrode active material of the lithium ion battery, and the remaining steps of the preparation method of the lithium ion battery are the same as the usual preparation method. The preparation method of electrode sheet is as follows, adopt dicobalt selenide nickel hollow nano-prism material as active material, acetylene black as conductive agent, carboxymethyl cellulose as binding agent, active material, acetylene black, carboxymethyl cellulose The mass ratio is 60:30:10; after fully mixing them in proportion, ultrasonically mix them for 30 minutes, and then evenly coat them on the copper foil, and the loading capacity of the active substance is 1.2-1.5g cm ^-1 Fill it into a disc with a punching machine, and place the prepared negative electrode sheet in an oven at 60° C. to dry for 24 hours before use. 1M lithium hexafluorophosphate dissolved in ethylene carbonate (EC) and dimethyl carbonate (DMC) was used as the electrolyte, the lithium sheet was used as the positive electrode, Celgard 2325 was used as the diaphragm, and CR 2016 stainless steel was used as the battery case to assemble a button-type lithium-ion battery.

Taking the nickel dicobalt selenide hollow nano-prism material prepared in this example as the active material as the negative electrode active material of lithium ion battery as an example, as shown in Figure 4, under the current density of 100mA g ^-1 , the initial capacity can reach 2011mAh g ^-1 , the capacity is still 1062mAh g ^-1 after 30 cycles. As shown in Figure 5, at a high current density of 2000mA g ^-1 , the initial capacity can reach 1110mAh g ^-1 , and the reversible capacity can reach 595mAh g ^-1 after 400 cycles. This result indicates that the nickel dicobalt selenide hollow nanoprism material has excellent high-capacity characteristics and is a potential application material for high-power, high-capacity, and long-life lithium-ion batteries.

Example 2:

A method for preparing a hollow cobalt-nickel tetraselenide nano-prism material, comprising the steps of:

1) Dissolve 5g of polyvinylpyrrolidone PVP-K17 powder, 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 83° C. in an oil bath under the device of condensation and reflux for 4 hours;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 70°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4) and 0.111 g of selenium dioxide powder, dissolve it in 35 ml of benzyl alcohol solution, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 160° C. for 15 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 70° C. to obtain a hollow nano-prism material of nickel dicobalt selenide;

Taking the product of this example as an example, the material is a hollow nano-prism material, and the hollow nano-prism has a length of 1-1.5 micrometers and a width of 150-250 nanometers.

Taking the hollow nickel dicobalt selenide nano-prism nanomaterial prepared in this example as the negative electrode active material of lithium ion battery, at a current density of 2000mA g ^-1 , the first discharge specific capacity can reach 1140mAh g ^-1 , and the cycle time is 400 times. Afterwards, the reversible specific capacity can still reach 585mAh g ^-1 .

Example 3:

A method for preparing a hollow cobalt-nickel tetraselenide nano-prism material, comprising the steps of:

1) Dissolve 5g of polyvinylpyrrolidone PVP K-30 powder, 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 83° C. in an oil bath under the device of condensation and reflux for 4 hours;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 60°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4), and dissolve it in 35 ml of benzyl alcohol solution with 0.111 g of selenium dioxide powder, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 140° C. for 12 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 60°C

Dry, obtain dicobalt-nickel tetraselenide hollow nano-prism material;

Taking the product of this example as an example, the material is a hollow nano-prism material, and the hollow nano-prism has a length of 1-1.5 micrometers and a width of 150-250 nanometers.

Taking the hollow nickel dicobalt selenide nano-prism nanomaterial prepared in this example as an example for the negative electrode active material of lithium ion battery, at a current density of 2000mA g ^-1 , the first discharge specific capacity can reach 1151mAh g ^-1 , and after 400 cycles The reversible specific capacity can still reach 593mAh g ^-1 .

Example 4:

A method for preparing a hollow cobalt-nickel tetraselenide nano-prism material, comprising the steps of:

1) Dissolve 5g of polyvinylpyrrolidone PVP-K13 powder, 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 84° C. in an oil bath under the device of condensation and reflux for 5 hours;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 70°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4), and 0.111 g of selenium dioxide powder, dissolve it in 35 ml of benzyl alcohol solution, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 140°C for 20 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 70° C. to obtain a hollow nano-prism material of nickel dicobalt selenide;

Taking the product of this example as an example, the material is a hollow nano-prism material, and the hollow nano-prism has a length of 1-1.5 micrometers and a width of 150-250 nanometers.

Taking the hollow nickel dicobalt selenide nano-prism nanomaterial prepared in this example as an example for the negative electrode active material of lithium-ion batteries, at a current density of 2000mA g ^-1 , the first discharge specific capacity can reach 1150mAh g ^-1 , and after 400 cycles The reversible specific capacity can still reach 588mAh g ^-1 .

Example 5:

A method for preparing a hollow cobalt-nickel tetraselenide nano-prism material, comprising the steps of:

1) Dissolve 5g of polyvinylpyrrolidone PVP-K17 powder, 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 86°C in an oil bath under the device of condensation and reflux for 4 hours;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 70°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4) and 0.111 g of selenium dioxide powder, dissolve it in 35 ml of benzyl alcohol solution, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 160°C for 20 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 70° C. to obtain a hollow nano-prism material of nickel dicobalt selenide;

Taking the product of this example as an example, the material is a hollow nano-prism material, and the hollow nano-prism has a length of 1-1.5 micrometers and a width of 150-250 nanometers.

Taking the hollow nickel dicobalt selenide nano-prism nanomaterial prepared in this example as an example for the negative electrode active material of lithium ion battery, at a current density of 2000mA g ^-1 , the first discharge specific capacity can reach 1136mAh g ^-1 , and after 400 cycles The reversible specific capacity can still reach 593mAh g ^-1 .

Comparative example 6:

A method for preparing a hollow nickel dicobalt selenide nanosphere material, comprising the steps of:

1) Dissolve 5g of polyvinylpyrrolidone PVP-K17 powder, 1.28g of nickel acetate tetrahydrate and cobalt acetate tetrahydrate powder (ratio: 1:2) in 200mL ethanol solution;

2) Fully stir in the solution obtained in step 1) at room temperature to obtain a solution;

3) Heat the solution obtained in step 2) to 80°C in an oil bath under the device of condensation and reflux for 4 hours;

4) Centrifugally filter the product obtained in step 3), wash the obtained precipitate with absolute ethanol at least 10 times, and dry it in an oven at 70°C to obtain a nickel-cobalt precursor;

5) Measure 125 mg of the precursor obtained in step 4) and 0.111 g of selenium dioxide powder, dissolve it in 35 ml of benzyl alcohol solution, and stir fully at room temperature;

6) Transfer the solution obtained in step 5) to a reaction kettle, and fully react at 180° C. for 12 hours;

7) Centrifugally filter the product obtained in step 6), repeatedly wash the obtained precipitate with absolute ethanol, and dry it in an oven at 70° C. to obtain a hollow nanosphere material of nickel dicobalt selenide;

Taking the product of this example as an example, the material is a hollow nanosphere material, and the diameter of the hollow nanosphere is 250-300 nanometers. Its transmission electron microscope picture is shown in Fig. 6.

Claims (7)

1. a kind of hollow nanoprisms material of cobalt nickel of four selenizing two, it is hollow structure, 1~1.5 micron of the nanoprisms length, It is wide 150~250 nanometers.

2. the preparation method of the hollow nanoprisms material of the cobalt nickel of four selenizing two described in claim 1, it is characterised in that include Following steps：

1) nickel cobalt presoma is weighed into 125mg and 0.111g selenium dioxide powder, is dissolved in 35ml benzyl alcohol solutions, fills at room temperature Divide stirring；

2) by step 1) resulting solution is transferred in reactor, and heating is to carry out solvent thermal reaction；

3) by step 3) products therefrom centrifugal filtration, cyclic washing gained sediment, drying.

3. the preparation method of the hollow nanoprisms material of the cobalt nickel of four selenizing two according to claim 2, it is characterised in that institute The preparation method for the nickel cobalt presoma stated is：

A) it is 1 to measure 5g polyvinylpyrrolidone PVP powder, mass ratio:The 2 hydration nickel acetates of 1.28g tetra- and four hydration vinegar The mixing of sour cobalt dust, is dissolved in organic solution, is sufficiently stirred at room temperature；

B) by step a) resulting solutions under the device of condensing reflux heating response；

C) by step b) products therefrom centrifugal filtrations, gained sediment is washed, drying obtains nickel cobalt presoma.

4. the preparation method of the hollow nanoprisms material of the cobalt nickel of four selenizing two according to claim 3, it is characterised in that institute The polyvinylpyrrolidone PVP stated is PVP-K13, PVP-K17 or PVP-K30, wherein described PVP-K13, PVP-K17 MW ~10000.

5. the preparation method of the hollow nanoprisms material of the cobalt nickel of four selenizing two according to claim 3, it is characterised in that step Suddenly b) described in reaction temperature be 80~90 DEG C, the reaction time be 3~6 hours.

6. the preparation method of the hollow nanoprisms material of the cobalt nickel of four selenizing two according to claim 2, it is characterised in that step It is rapid 2) described in reaction temperature be 120~160 DEG C, the reaction time be 8~24 hours.

7. the hollow nanoprisms material of the cobalt nickel of four selenizing two described in claim 1 is lived as lithium ion or sodium-ion battery negative pole The application of property material.