CN113725434B - Nickel-based metal organic frame derived composite electrode and preparation method thereof - Google Patents

Abstract

The invention provides a composite electrode material derived from a nickel-based metal-organic framework and a preparation method thereof. The preparation method comprises the following steps: (1) dissolving nickel chloride hexahydrate and malonic acid in N, N di (2) Mix the two solutions and put them in an oven for reaction; (3) Wash the product obtained from the above reaction, and dry the product after centrifugation to obtain the precursor material ; (4) Raise the temperature of the precursor material in a tube furnace first, and then anneal to obtain the flower-shaped electrode material; (5) Mix the flower-shaped electrode material with conductive carbon black and PVDF adhesive to form a mixture, and then add In N, N-dimethylpyrrolidone, use a high-speed internal rotary beater to disperse the slurry to obtain a black colloidal slurry; (6) evenly coat the black colloidal slurry on the pre-treated copper foil, and Place in a vacuum drying oven and dry to prepare a composite electrode material.

Description

A composite electrode derived from a nickel-based metal-organic framework and its preparation method

technical field

The invention relates to the technical field of preparation of energy storage devices and new materials, in particular to a composite electrode material derived from a nickel-based metal organic framework and a preparation method thereof.

Background technique

At present, the energy density of commercial lead-acid batteries, alkaline zinc-manganese and other secondary batteries can no longer meet the growing needs of the people. At the same time, lead-acid batteries and alkaline zinc-manganese batteries still have many problems, such as poor portability, difficult recycling, and unfriendly environment. In order to solve the above problems, researchers have developed many new energy storage devices, such as fuel cells, aluminum-ion batteries, lithium-air batteries, magnesium-ion batteries, lithium-sulfur batteries, sodium-ion batteries, and potassium-ion batteries. However, they also have problems such as cycle performance and safety performance that need to be further resolved, so they are still far from commercialization. Lithium-ion batteries with excellent performance have been widely used and gradually become the mainstream of secondary batteries. However, with the improvement of people's living standards, there is an urgent need for lithium-ion batteries with better performance.

Nickel-based MOFs have been widely used in various fields, such as gas separation/storage, sewage treatment, optical devices, and energy storage. At present, Ni-based metal-organic framework-derived materials with regular morphology, especially by adjusting the reaction conditions, have been extensively studied. Many literatures have reported uniform and regular nickel-based metal-organic framework-derived materials, which can have excellent electrochemical performance.

The current research on lithium-ion anode materials is mainly focused on the development of transition metal oxides and transition metal sulfides with different morphologies, and relatively good results have been achieved. However, the research on new nickel-based metal-organic framework materials is still less, especially the flower-like materials derived from nickel-based metal-organic framework materials.

Contents of the invention

In order to solve the above technical problems, the first aspect of the present invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Dissolve nickel chloride hexahydrate and malonic acid in N,N-dimethylformamide respectively, and stir to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir evenly, transfer to a polytetrafluoroethylene-lined reactor and place in an oven for reaction;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) Put the precursor material obtained in step (3) into a porcelain boat and transfer it to a tube furnace, heat it up in an air atmosphere, and then perform annealing treatment to obtain a flower-shaped electrode material;

(5) Mix the flower-shaped electrode material obtained in step (4) with conductive carbon black and PVDF adhesive to form a mixture, then add the mixture to N,N-dimethylpyrrolidone, and use high-speed internal rotation to beat Machine dispersed slurry to obtain black colloidal slurry;

(6) The black colloidal slurry obtained in step (5) is evenly coated on the pre-treated copper foil, and dried in a vacuum oven to prepare a composite electrode material.

Wherein, the mass ratio of the nickel chloride hexahydrate to the malonic acid is 2-3:1.

Preferably, the mass ratio of the nickel chloride hexahydrate to the malonic acid is 2.2:1, 2.4:1, 2.5:1, 2.6:1, 2.8:1.

Wherein, the mass volume ratio of the nickel chloride hexahydrate and the N,N-dimethylformamide is 3~8:100 g/mL, the malonic acid and the N,N-dimethylformamide The mass volume ratio of formamide is 1~5:100 g/mL.

Preferably,

The mass volume ratio of described nickel chloride hexahydrate and described N, N-dimethylformamide is 4:100 g/mL, 5:100 g/mL, 6:100 g/mL, 7:100 g/mL ;

The mass volume ratio of the malonic acid to the N,N-dimethylformamide is 2:100 g/mL, 3:100 g/mL, and 4:100 g/mL.

Wherein, the mass ratio of the flower-shaped electrode material, the conductive carbon black and the PVDF adhesive is 7-10:1:1.

Preferably, the mass ratio of the flower-like electrode material, the conductive carbon black and the PVDF adhesive is 8:1:1, 9:1:1.

Wherein, the mass volume ratio of the mixture formed by the flower-like electrode material, the conductive carbon black and the PVDF adhesive to the N,N-dimethylpyrrolidone is 0.20-0.24:100 g/mL.

Preferably, the mass volume ratio of the mixture to the N,N-dimethylpyrrolidone is 0.21:100 g/mL, 0.22:100 g/mL, and 0.23:100 g/mL.

Wherein, in the step (2), the reaction temperature is 150-200° C., and the reaction time is 10-15 hours.

Preferably,

The reaction temperature is 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C;

The reaction time is 11h, 12h, 13h, 14h.

Wherein, in the step (4), the temperature is raised to 450-550° C. at a heating rate of 2-5° C./min in an air atmosphere, and then annealed for 1-4 hours to obtain a flower-shaped electrode material.

Wherein, in the step (6), the drying temperature is 50-80° C., and the drying time is 10-15 hours.

Preferably,

The drying temperature is 55°C, 60°C, 65°C, 70°C, 75°C;

The drying time is 11h, 12h, 13h, 14h.

The second aspect of the present invention provides a composite electrode material derived from a nickel-based metal organic framework, which is prepared according to the method provided in the first aspect of the present invention.

Beneficial effects of the present invention:

The nickel-based metal-organic framework-derived composite electrode material prepared by the simple hydrothermal method of the present invention has a high capacity, which is mainly due to its stable porous structure and special morphology, which is conducive to electrolyte infiltration and effective mitigation. The volume expansion and structural pulverization of the electrode material during the charge and discharge process enhances the electrochemical performance.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings that need to be used in the implementation will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention, corresponding to common As far as the skilled person is concerned, other drawings can also be obtained based on these drawings on the premise of not paying creative work.

Fig. 1 is the XRD spectrum of the nickel-based metal-organic framework material prepared by the method provided in Example 1 of the present invention;

Figure 2 and Figure 3 are SEM images of the nickel-based metal-organic framework-derived composite electrode material prepared by the method provided in Example 1 of the present invention;

Fig. 4 is a charge-discharge curve diagram of a composite electrode material derived from a nickel-based metal-organic framework prepared by the method provided in Example 1 of the present invention;

Fig. 5 is a cycle graph of the nickel-based metal-organic framework-derived composite electrode material prepared by the method provided in Example 1 of the present invention at a current density of 0.1 A g ^-1 ;

FIG. 6 is an impedance curve of the nickel-based metal-organic framework-derived composite electrode material prepared by the method provided in Example 1. FIG.

Implementation

The following are preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered as the present invention. protection scope of the invention.

Example 1

The invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Weigh 0.5 g of nickel chloride hexahydrate and 0.2 g of malonic acid and dissolve them in 10 mL of N,N-dimethylformamide respectively, and stir for 10 min to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir for 20 min to mix evenly, then transfer to a 50 mL polytetrafluoroethylene-lined reaction kettle, place in an oven, and react at 180°C for 12 h;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) The precursor material obtained in step (3) was placed in a porcelain boat and transferred to a tube furnace, and the temperature was raised to 500 °C at a rate of 2 °C/min in an air atmosphere, and then annealed for 2 h to obtain a flower shaped electrode material;

(5) Weigh 17.6 mg of the flower-shaped electrode material obtained in step (4), 2.2 mg of conductive carbon black and 2.2 mg of PVDF adhesive to form a mixture, and then add the mixture to 10 mL of N,N-dimethyl In pyrrolidone, disperse the slurry with a high-speed internal rotary beater, 1 minute each time, repeat 5 times, and obtain a black colloidal slurry;

(6) Coat the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, place it in a vacuum drying oven, and dry it at 60°C for 12 hours to prepare a composite electrode material .

Composite electrode material prepared in embodiment 1 is assembled into a button cell to evaluate, with lithium foil as reference electrode, polypropylene porous membrane (Celgard 2300) is separator, electrolyte is 1mol/L LiPF ₆ and ethylene carbonate and A mixed solution of diethyl carbonate (w/w, 1/1) was used to assemble the battery in a glove box filled with high-purity argon. On the LAND-CT2001C system, the lithium intercalation and delithiation cycles were performed on the battery at a current of 0.1 A g ^-1 , and on the Chenhua 760E electrochemical station, at 0.1 mVs ^-1 , the test voltage range was 1 mV-3.0 V , for a CV test.

Fig. 1 is the XRD spectrum of the nickel-based metal-organic framework material prepared by the method provided in Example 1, as can be seen from the figure, there are five different characteristic peaks, thus it can be seen that the stable crystal of the nickel-based metal-organic framework material structure.

Figure 2 and Figure 3 are SEM images of the nickel-based metal-organic framework-derived composite electrode material prepared by the method provided in Example 1. It can be seen from the figure that the electrode material is a flower-like structure with a diameter of about 200-300 nm .

Fig. 4 is the charge-discharge curve diagram of the composite electrode material derived from the nickel-based metal-organic framework prepared by the method provided in Example 1. From the curve in the first circle of the figure, the platform of the reaction can be clearly seen, while the nickel-based metal-organic framework The Coulombic efficiency of the derived composite electrode is 68.2%, and the main reason for the capacity loss is the formation of solid electrolyte interfacial film.

Figure 5 is the cycle curve of the nickel-based metal-organic framework-derived composite electrode material prepared by the method provided in Example 1 at a current density of 0.1 A g ^-1 . It can be seen from the figure that after the first 10 cycles, it reaches 1205 mAh g ^-1 , it can be seen that the composite electrode material derived from nickel-based metal-organic framework is a potential high-performance electrode material.

Figure 6 is the impedance curve of the composite electrode material derived from the nickel-based metal-organic framework prepared by the method provided in Example 1. It can be seen from the figure that the impedance of the flower-shaped electrode material is only 130 Ω after one cycle. It can be seen that, Nickel-based metal-organic framework-derived composite electrode materials exhibit high electrical conductivity.

Example 2

The invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Weigh 0.4 g of nickel chloride hexahydrate and 0.2 g of malonic acid and dissolve them in 10 mL of N,N-dimethylformamide respectively, and stir for 10 min to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir for 20 minutes to mix evenly, then transfer to a 50 mL polytetrafluoroethylene-lined reaction kettle, place in an oven, and react at 160°C for 14 hours;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) The precursor material obtained in step (3) was placed in a porcelain boat and transferred to a tube furnace, heated to 480 °C at a rate of 4 °C/min in an air atmosphere, and then annealed for 3 h to obtain a flower shaped electrode material;

(5) Weigh 16.0 mg of the flower-shaped electrode material obtained in step (4), 2.0 mg of conductive carbon black and 2.0 mg of PVDF adhesive and mix evenly to form a mixture, and then add the mixture to 10 mL of N,N-dimethyl In pyrrolidone, disperse the slurry with a high-speed internal rotary beater, 1 min each time, repeat 6 times, and obtain a black colloidal slurry;

(6) Coat the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, place it in a vacuum drying oven, and dry it at 55°C for 14 hours to prepare a composite electrode material .

Example 3

The invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Weigh 0.6 g of nickel chloride hexahydrate and 0.2 g of malonic acid and dissolve them in 10 mL of N,N-dimethylformamide respectively, and stir for 10 min to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir for 20 minutes to mix evenly, then transfer to a 50 mL polytetrafluoroethylene-lined reactor, place in an oven, and react at 200°C for 10 hours;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) The precursor material obtained in step (3) was placed in a porcelain boat and transferred to a tube furnace, and the temperature was raised to 520 °C at a rate of 3 °C/min in an air atmosphere, and then annealed for 1.5 h to obtain a flower shaped electrode material;

(5) Weigh 17.5 mg of the flower-shaped electrode material obtained in step (4), 2.5 mg of conductive carbon black and 2.5 mg of PVDF adhesive and mix evenly to form a mixture, and then add the mixture to 10 mL of N,N-dimethyl In pyrrolidone, disperse the slurry with a high-speed internal rotary beater, 1 min each time, repeat 5 times, and obtain a black colloidal slurry;

(6) Coat the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, place it in a vacuum drying oven, and dry it at 50°C for 15 hours to prepare a composite electrode material .

Example 4

The invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Weigh 0.5 g of nickel chloride hexahydrate and 0.2 g of malonic acid and dissolve them in 10 mL of N,N-dimethylformamide respectively, and stir for 10 min to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir for 20 minutes to mix evenly, then transfer to a 50 mL polytetrafluoroethylene-lined reaction kettle, place in an oven, and react at 170°C for 13 hours;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) Put the precursor material obtained in step (3) in a porcelain boat and transfer it to a tube furnace, raise the temperature to 450°C at a heating rate of 5°C/min in an air atmosphere, and then perform annealing treatment for 4 hours to obtain a flower-shaped electrode material;

(5) Weigh 20.0 mg of the flower-shaped electrode material obtained in step (4), 2.0 mg of conductive carbon black and 2.0 mg of PVDF adhesive and mix evenly to form a mixture, and then add the mixture to 10 mL of N,N-dimethyl In pyrrolidone, disperse the slurry with a high-speed internal rotary beater, 1 min each time, repeat 6 times, and obtain a black colloidal slurry;

(6) Coat the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, place it in a vacuum drying oven, and dry it at 75°C for 11 h to prepare a composite electrode material .

Example 5

The invention provides a method for preparing a composite electrode material derived from a nickel-based metal organic framework, comprising the following steps:

(1) Weigh 0.6 g of nickel chloride hexahydrate and 0.2 g of malonic acid and dissolve them in 10 mL of N,N-dimethylformamide respectively, and stir for 10 min to completely dissolve nickel chloride hexahydrate and malonic acid;

(2) Mix the two solutions obtained in step (1), stir for 20 minutes to mix evenly, then transfer to a 50mL polytetrafluoroethylene-lined reactor, place in an oven, and react at 150°C for 15 hours;

(3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material;

(4) The precursor material obtained in step (3) was placed in a porcelain boat and transferred to a tube furnace, and the temperature was raised to 550 °C at a rate of 3 °C/min in an air atmosphere, and then annealed for 1 h to obtain a flower shaped electrode material;

(5) Weigh 20.0 mg of the flower-shaped electrode material obtained in step (4), 2.0 mg of conductive carbon black and 2.0 mg of PVDF adhesive and mix uniformly to form a mixture, and then add 10 mL of N,N-dimethylpyrrolidone to the mixture In the process, disperse the slurry with a high-speed internal rotary beater, 1 minute each time, repeat 5 times, and obtain a black colloidal slurry;

(6) Coat the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, place it in a vacuum drying oven, and dry it at 65°C for 12 hours to prepare a composite electrode material .

The above examples only express the specific implementation manner of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (5)

1. A method for preparing a composite electrode derived from a nickel-based metal-organic framework, comprising the following steps: (1) Dissolve nickel chloride hexahydrate and malonic acid in N,N-dimethylformamide respectively, and stir to completely dissolve nickel chloride hexahydrate and malonic acid; (2) Mix the two solutions obtained in step (1), stir evenly, transfer to a polytetrafluoroethylene-lined reactor and place in an oven for reaction; (3) Wash the reaction product obtained in step (2) with water, N,N-dimethylformamide and ethanol in sequence to remove unreacted ions, and dry the product obtained by centrifugation in a vacuum drying oven to obtain the former body material; (4) Put the precursor material obtained in step (3) into a porcelain boat and transfer it to a tube furnace, heat it up in an air atmosphere, and then perform annealing treatment to obtain a flower-shaped electrode material; (5) Mix the flower-shaped electrode material obtained in step (4) with conductive carbon black and PVDF adhesive to form a mixture, then add the mixture to N,N-dimethylpyrrolidone, and use high-speed internal rotation to beat Machine dispersed slurry to obtain black colloidal slurry; (6) Coating the black colloidal slurry obtained in step (5) evenly on the pre-treated copper foil, and drying in a vacuum oven to prepare a composite electrode; The mass ratio of described nickel chloride hexahydrate and described malonic acid is 2～3:1; The mass volume ratio of described nickel chloride hexahydrate and described N, N-dimethylformamide is 3～8:100 g/mL, described malonic acid and described N, N-dimethylformamide The mass volume ratio is 1~5:100 g/mL; In step (2), the reaction temperature is 150~200°C, and the time is 10~15h; In step (4), the temperature is raised to 450-550° C. at a heating rate of 2-5° C./min in an air atmosphere, and then annealed for 1-4 hours to obtain a flower-shaped electrode material. 2. The method for preparing a composite electrode derived from a nickel-based metal-organic framework according to claim 1, wherein the mass ratio of the flower-shaped electrode material, the conductive carbon black and the PVDF adhesive is 7~10:1:1. 3. The method for preparing a composite electrode derived from a nickel-based metal organic framework according to claim 1, characterized in that: the mixture of the flower-shaped electrode material, the conductive carbon black and the PVDF adhesive is formed with The mass-to-volume ratio of the N, N-dimethylpyrrolidone is 0.20-0.24:100 g/mL. 4. The method for preparing a nickel-based metal-organic framework-derived composite electrode according to any one of claims 1-3, characterized in that: in step (6), the drying temperature is 50-80°C, and the drying time is 10~15h. 5. A composite electrode derived from a nickel-based metal-organic framework, characterized in that: the composite electrode is prepared according to the preparation method described in any one of claims 1-4.

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