阅读说明：本技术 球状Cu-Ni-S复合纳米材料及其制备方法和应用 (Spherical Cu-Ni-S composite nano material and preparation method and application thereof ) 是由 徐锡金 王同凯 王晓 李晓娟 李传琳 张伟杰 于 2021-08-09 设计创作，主要内容包括：本发明涉及纳米电极材料领域,具体涉及一种球状Cu-Ni-S复合纳米材料及其制备方法和应用。实验首次发现,Cu-Ni-S三种成分复合,可以在没有碳布或其他基体的条件下形成均匀球状结构,同时球状Cu-Ni-S复合纳米材料作为电极材料在电流密度为10A/g～(-1)时循环10000圈,球状Cu-Ni-S复合纳米材料电极的循环保持率高于98％。当电流密度为1A g～(-1)时球状Cu-Ni-S复合材料的比电容为52.4mAh g～(-1),同时具有极好的导电性和循环稳定性。(The invention relates to the field of nano electrode materials, in particular to a spherical Cu-Ni-S composite nano material and a preparation method and application thereof. Experiments show that the Cu-Ni-S three components are compounded to form a uniform spherical structure without carbon cloth or other matrixes, and meanwhile, the spherical Cu-Ni-S composite nano material is used as an electrode material and has the current density of 10A/g ‑1 10000 cycles of time circulation, and the circulation retention rate of the spherical Cu-Ni-S composite nano material electrode is higher than 98 percent. When the current density is 1A g ‑1 The specific capacitance of the spherical Cu-Ni-S composite material is 52.4mAh g ‑1 And simultaneously has excellent conductivity and cycle stability.)

1. A preparation method of a spherical Cu-Ni-S composite nano material is characterized by comprising the following steps: mixing nickel salt and copper salt in a solvent, adding a sulfur source and a catalyst, carrying out hydrothermal reaction, washing and drying to obtain the catalyst.

2. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the nickel salt is selected from one or more of nickel nitrate, nickel sulfate, and nickel chloride;

preferably, the copper salt is selected from one or more of copper nitrate, copper sulfate and copper chloride;

preferably, the sulfur source is selected from carbon disulfide;

preferably, the molar ratio of the nickel salt to the copper salt is 0.2-1.0:0.2-1.0, preferably 0.5: 1.

3. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the solvent is selected from one or more of methanol, ethanol, dimethyl sulfoxide, dimethylformamide and dimethylacetamide;

preferably, the concentration of the nickel salt in the solvent is 0.04-0.2mmol/mL, preferably 0.1 mmol/mL;

preferably, the concentration of the copper salt in the solvent is 0.08-0.4mmol/mL, preferably 0.2 mmol/mL.

4. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the catalyst is pentamethyldiethylenetriamine;

preferably, the volume ratio of the carbon disulfide to the pentamethyldiethylenetriamine is 1.0-1.5:10, preferably 1.2: 10;

preferably, the volume ratio of carbon disulphide and solvent is in the range of from 0.1 to 0.15:5, preferably 0.12: 5.

5. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the hydrothermal reaction temperature is 150 ℃ to 200 ℃ and the reaction time is 8-12 hours, preferably 180 ℃ to 10 hours.

6. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the washing is performed by alternately washing with deionized water and ethanol;

preferably, the drying condition is vacuum drying at 60 ℃ for 10-12 hours.

7. The method for preparing the spherical Cu-Ni-S composite nanomaterial according to claim 1, wherein the method for preparing comprises: dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 10 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial.

8. The spherical Cu-Ni-S composite nanomaterial produced by the method for producing a spherical Cu-Ni-S composite nanomaterial according to any one of claims 1 to 7.

9. Use of the spherical Cu-Ni-S composite nanomaterial of claim 8 in the preparation of an electrode.

10. A battery electrode comprising the spherical Cu-Ni-S composite nanomaterial of claim 8.

Technical Field

The invention relates to the field of nano electrode materials, in particular to a spherical Cu-Ni-S composite nano material and a preparation method and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

In recent years, micro-nano materials show certain activity in a plurality of fields due to excellent optical, electrical and other physicochemical properties, such as solar radiation absorbers, polymer material improvement, anode materials of lithium ion batteries, nano switches, catalysts and other fields. The different appearances of the micro-nano material provide an adjustable variable for the performance of the material, and the variable has great influence on the properties of the material, such as catalysis, optics, electronic application and the like. Therefore, scientists have carried out a great deal of research on the control of the morphology and the structure of the micro-nano material and developed the potential application value of the micro-nano material in the fields of environmental protection, biomedicine, aerospace technology and the like. Transition metal sulfides are one of the hot spots of today's nanomaterials. In recent years, there have been some methods available for practical production, including electrochemical reaction, vapor deposition, soft and hard template, and the like.

The inventors have found that, although significant research efforts have been put into commercial use, there is still a lack of simple and efficient mass production of commercial nanomaterials. For example: preparation of ternary NiCo₂S₄Low electrode capacity, poor circulation stability at 10mAcm^-2After 6000 times of cyclic charge-discharge tests at the current density of (A), the original NiCo₂S₄The electrode retention rate is 59.46%, even after Mn load modification is used, the cycle performance of the electrode material is still lower than 90%, and 0.5Mn-NiCo₂S₄The retention rate of the electrode capacity is 78.95 percent, and the content of 0.2Mn-NiCo₂S₄The electrode of (2) was 58.29%, 1Mn-NiCo₂S₄The electrode of (2) was 73.68%.

In addition, in the preparation process, hydrochloric acid and acetone are also needed for cleaning, which indicates that the electrode material has more impurities, carbon cloth is used for preparing the ternary electrode material, the preparation process is complex, and NiCo is a complex product₂S₄The carbon cloth can not form a uniform phase structure, which is not beneficial to practical industrial application.

Disclosure of Invention

In order to improve the initial battery capacity and the cycling stability of the conventional ternary electrode material and simplify the preparation method, the invention provides a spherical Cu-Ni-S composite nano material and a preparation method and application thereof, and experiments show that the Cu-Ni-S three components are compounded to form a uniform spherical structure without carbon cloth or other matrixes for the first time, and meanwhile, the spherical Cu-Ni-S composite nano material is used as an electrode material and has the current density of 10mA/g^-110000 cycles of time circulation, and the circulation retention rate of the spherical Cu-Ni-S composite nano material electrode is higher than 98 percent. When the current density is 1Ag^-1The specific capacitance of the spherical Cu-Ni-S (CNS) composite material is 52.4mAh g^-1And simultaneously has excellent conductivity and cycle stability.

Specifically, the invention is realized by the following technical scheme:

in a first aspect of the present invention, a method for preparing a spherical Cu-Ni-S composite nanomaterial is provided, comprising: mixing nickel salt and copper salt in a solvent, adding a sulfur source and a catalyst, carrying out hydrothermal reaction, washing and drying to obtain the catalyst.

In a second aspect of the invention, the spherical Cu-Ni-S composite nano-material is prepared by the preparation method of the spherical Cu-Ni-S composite nano-material.

In a third aspect of the invention, the invention provides an application of a spherical Cu-Ni-S composite nano material in preparing an electrode.

In a fourth aspect of the invention, a battery electrode is provided comprising a spherical Cu-Ni-S composite nanomaterial.

One or more embodiments of the present invention have the following advantageous effects:

1) experiments show that the Cu-Ni-S three components are compounded to form a uniform spherical structure without carbon cloth or other matrixes for the first time.

2) The high-performance spherical Cu-Ni-S composite nano material is prepared by a simple one-step hydrothermal method, so that the risk of vulcanization by a common vapor deposition method can be reduced, and the complexity of multi-step operation can be reduced. In the preparation process, when the time of the hydrothermal reaction is controlled to be 8-12 h, the temperature of the hydrothermal reaction is 170-190 ℃, and the spherical Cu-Ni-S composite nano material can be formed; wherein when the time of the hydrothermal reaction is controlled to be 10 hours and the temperature of the hydrothermal reaction is 180 ℃, the spherical Cu-Ni-S composite nano material with good appearance can be formed.

3) Spherical Cu-Ni-S composite nano material as electrode material with current density of 10A g^-110000 cycles of time circulation, and the circulation retention rate of the spherical Cu-Ni-S composite nano material electrode is higher than 98 percent. When the current density is 10A g^-1The specific capacitance of the spherical Cu-Ni-S composite material is 8.5mAh g^-1And simultaneously has excellent conductivity and cycle stability.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 is SEM images of spherical Cu-Ni-S composite nano-materials prepared in example 1 of the present invention at different magnifications;

FIG. 2 is an X-ray diffraction pattern (XRD) of the spherical Cu-Ni-S composite nanomaterial prepared in example 1 of the present invention;

FIG. 3 is a CV (cyclic voltammetry) curve of the spherical Cu-Ni-S composite nanomaterial prepared in example 1 of the present invention at different sweep rates;

FIG. 4 is a constant current charge and discharge (GCD) diagram of the spherical Cu-Ni-S composite nanomaterial prepared in example 1 of the present invention at different current densities;

FIG. 5 is an impedance spectroscopy (EIS) of a spherical Cu-Ni-S composite nanomaterial electrode prepared in example 1 of the present invention;

FIG. 6 shows the spherical Cu-Ni-S composite nano-tube prepared in example 1 of the present inventionThe rice material has a current density of 10Ag^-1Cycle life plots of time-in-time electrodes;

FIG. 7 is an SEM image of CNS-160 nanomaterials prepared according to example 2 of the invention at different magnifications;

FIG. 8 is an SEM image of CNS-200 nanomaterial prepared according to the invention 3 at different magnifications;

FIG. 9 is an SEM image of the CNS-8h nanomaterial prepared in example 4 of the present invention at different magnifications;

FIG. 10 is an SEM image of CNS-12h nanomaterials prepared according to example 5 of the present invention at different magnifications;

FIG. 11 is an SEM image of CNS-1:1 nanomaterials prepared according to example 6 of the invention at different magnifications;

FIG. 12 is an SEM image of CNS-2:1 nanomaterials prepared according to example 7 of the invention at different magnifications;

FIG. 13(a) is a CV (cyclic voltammogram) curve at different sweep rates for the CNS-160 composite nanomaterials prepared in example 2 of the present invention; FIG. 13(b) is a graph of constant current charging and discharging (GCD) at different current densities for the CNS-160 composite nanomaterial prepared in example 2 of the present invention; FIG. 13(c) is a CV (cyclic voltammogram) curve of the CNS-200 composite nanomaterial prepared in example 3 of the present invention at different sweep rates; FIG. 13(d) is a constant current charge and discharge (GCD) plot of the CNS-200 composite nanomaterial prepared in example 3 of the present invention at different current densities;

FIG. 14(a) is a CV (cyclic voltammogram) curve of CNS-8h composite nanomaterials prepared in example 4 of the present invention at different sweep rates; FIG. 14(b) is a constant current charge and discharge (GCD) plot of the CNS-8h composite nanomaterial prepared in example 4 of the present invention at different current densities; FIG. 14(c) is a CV (cyclic voltammogram) curve of CNS-12h composite nanomaterials prepared in example 5 of the present invention at different sweep rates. FIG. 14(d) is a constant current charge and discharge (GCD) plot of the CNS-12h composite nanomaterial prepared in example 5 of the present invention at different current densities;

FIG. 15(a) is a CV (cyclic voltammogram) curve at different sweep rates for the CNS-1:1 composite nanomaterials prepared in example 6 of the present invention; FIG. 15(b) is a constant current charge and discharge (GCD) plot of the CNS-1:1 composite nanomaterial prepared in example 6 of the present invention at different current densities; FIG. 15(c) is a CV (cyclic voltammogram) curve at different sweep rates for the CNS-2:1 composite nanomaterials prepared in example 7 of the present invention; FIG. 15(d) is a constant current charge and discharge (GCD) plot of the CNS-2:1 composite nanomaterial prepared in example 7 of the present invention at different current densities;

FIG. 16 is an X-ray diffraction pattern (XRD) of spherical Cu-Ni-S composite nanomaterials prepared in examples 2-7 of the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In order to improve the initial battery capacity and the cycling stability of the conventional ternary electrode material and simplify the preparation method, the invention provides a spherical Cu-Ni-S composite nano material and a preparation method and application thereof, and experiments show that the Cu-Ni-S three components are compounded to form a uniform spherical structure without carbon cloth or other matrixes for the first time, and meanwhile, the spherical Cu-Ni-S composite nano material is used as an electrode material and has the current density of 10A g^-110000 cycles of time circulation, and the circulation retention rate of the spherical Cu-Ni-S composite nano material electrode is higher than 98 percent. When the current density is 1A g^-1The specific capacitance of the spherical Cu-Ni-S composite material is 52.4mAh g^-1And simultaneously has excellent conductivity and cycle stability.

Specifically, the invention is realized by the following technical scheme:

in a first aspect of the present invention, a method for preparing a spherical Cu-Ni-S composite nanomaterial is provided, comprising: mixing nickel salt and copper salt in a solvent, adding a sulfur source and a catalyst, carrying out hydrothermal reaction, washing and drying to obtain the catalyst.

In the chemical synthesis field, the type, proportion and concentration of raw materials can influence the final appearance and performance of the material, and in one or more embodiments of the invention, the nickel salt is selected from one or more of nickel nitrate, nickel sulfate and nickel chloride; the copper salt is selected from one or more of copper nitrate, copper sulfate and copper chloride; the sulfur source is selected from carbon disulfide.

Experiments show that under the coordination action of the nickel salt, the copper salt and the sulfur source, the spherical electrode material with specific morphology can be synthesized without the existence of carbon cloth or other carriers or matrixes.

When the molar ratio of the nickel salt to the copper salt is 0.2-1.0:0.2-1.0, preferably 0.5:1, the nickel salt and the copper salt can be better mixed, so that the problem that the nickel salt or the copper salt is not well dissolved to influence the reaction process with the sulfur source and the catalyst and further influence the morphology and the performance of the spherical material is avoided.

The solvent can not only dissolve and disperse the raw materials, but also provide a certain reaction environment for the reaction of the raw materials. The solvent is selected from one or more of methanol, ethanol, dimethyl sulfoxide, dimethylformamide and dimethylacetamide.

In one or more embodiments of the invention, the concentration of the nickel salt in the solvent is 0.04-0.2mmol/mL, the concentration of the copper salt in the solvent is 0.08-0.4mmol/mL, and the concentration of the copper salt is 2 times the concentration of the nickel salt.

By comparing the CNS-1:2(Cu-Ni-S) with the CNS-1:1 and CNS-2:1, the cyclic voltammetry curve and the constant current charge-discharge performance, when the concentration of copper salt is 2 times of that of nickel salt, the composition of the final product of the material is not changed, but the composition proportion is obviously changed, the spherical shape is most uniform, and the whole material is less agglomerated. After the proportion is changed, the appearance is not uniform and agglomeration occurs, the cyclic voltammetry curve has extremely poor symmetry, and the capacity is far lower than that of CNS.

Experimental research shows that when the concentration of nickel salt in a solvent is 0.1mmol/mL and the concentration of copper salt in the solvent is 0.2mmol/mL, the Cu-Ni-S composite nano material can present a complete spherical structure, and under other concentration conditions, pits are formed on the surface of the spherical structure or the spherical structure is not uniform.

When the volume ratio of the carbon disulfide to the pentamethyl diethylenetriamine is 1.0-1.5:10, preferably 1.2:10, the carbon disulfide and the pentamethyl diethylenetriamine can not only be fully dissolved in the solvent, but also be mixed with the nickel salt and the copper salt to prepare the spherical Cu-Ni-S composite nano material.

When the volume ratio of the carbon disulfide to the solvent is 0.1-0.15:5, preferably 0.12:5, the carbon disulfide is used as a sulfur source to provide sulfur element for the system, and reacts with nickel salt and copper salt to prepare the spherical Cu-Ni-S composite nano material.

The hydrothermal reaction is to grow the spherical Cu-Ni-S composite nano material in situ in a solution system, and the shape, the structure and the performance of the spherical Cu-Ni-S composite nano material are influenced by the hydrothermal reaction conditions. In one or more embodiments of the present invention, the hydrothermal reaction temperature is 150 ℃ to 200 ℃, and the reaction time is 8 to 12 hours, preferably 180 ℃ to 10 hours.

The shape and the agglomeration state of the CNS material are influenced by changing the temperature and the time, the nucleation rate is high when the temperature is high, but the subsequent reaction causes the agglomeration of the material, so that the subsequent material has uneven generated shape. At low temperatures the material is not uniformly formed and the spherical surface does not grow uniformly. Time affects the material growth size, but too long a time also results in agglomeration of the material, resulting in non-uniformity of the material as a whole.

In order to remove the composite material and avoid redundant magazine cases, as the invention does not need to use substrates such as carbon cloth, in one or more embodiments of the invention, the washing is performed by alternately washing with deionized water and ethanol, and the drying condition is vacuum drying at 60 ℃ for 10-12 hours.

Specifically, the preparation method comprises the following steps: dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 10 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial.

The high-performance spherical Cu-Ni-S composite nano material is prepared by a simple one-step hydrothermal method, so that the risk of vulcanization by a common vapor deposition method can be reduced, and the complexity of multi-step operation can be reduced. In the preparation process, when the time of the hydrothermal reaction is controlled to be 8-12 h, the temperature of the hydrothermal reaction is 170-190 ℃, and the spherical Cu-Ni-S composite nano material can be formed; wherein when the time of the hydrothermal reaction is controlled to be 10 hours and the temperature of the hydrothermal reaction is 180 ℃, the spherical Cu-Ni-S composite nano material with good appearance can be formed. The prepared spherical Cu-Ni-S composite nano material is coated on flexible carbon cloth to prepare an electrode, and the electrode passes through a three-electrode test in 3mol/L KOH electrolyte, and when the current density is 1A g^-1The specific capacitance of the spherical Cu-Ni-S composite nano material is 52.4mAh g^-1The capacitance retention rate of ten thousand cycles at the current density of 10C is 98%, and the conductive material has excellent conductivity and cycling stability. And the preparation method is simple, the raw materials are easy to obtain, the cost is low, the process is simple, and the production is convenient.

In a second aspect of the invention, the spherical Cu-Ni-S composite nano-material is prepared by the preparation method of the spherical Cu-Ni-S composite nano-material.

In a third aspect of the invention, the invention provides an application of a spherical Cu-Ni-S composite nano material in preparing an electrode.

In a fourth aspect of the invention, a battery electrode is provided comprising a spherical Cu-Ni-S composite nanomaterial.

The present invention is described in further detail below with reference to specific examples, which are intended to be illustrative of the invention and not limiting.

Example 1

Dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 10 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Named CNS-2: 1.

The material obtained in example 1 was investigated:

FIGS. 1(a), (b), (c) and (d) are low-magnification and high-magnification SEM images of spherical Cu-Ni-S composite nanomaterials. In SEM, the prepared spherical Cu-Ni-S composite nano material is shown to be in a spherical structure and has uniform size. The surface concave-convex of the spherical structure is beneficial to increasing the specific surface area and exposing more active sites, and reduces the loss of ions and charges, thereby improving the performance of the material.

FIG. 2 is an XRD pattern of the spherical Cu-Ni-S composite nano-material, and the diffraction peak of the XRD pattern can clearly show that the spherical Cu-Ni-S composite nano-material is successfully synthesized.

The electrochemical properties of the obtained spherical Cu-Ni-S composite nano-material electrode are tested by a three-electrode system in 3mol/L KOH solution.

FIG. 3 is CV (cyclic voltammetry curve) of the spherical Cu-Ni-S composite nanomaterial prepared in example 1 at different scanning speeds, and it can be seen from the graph that as the scanning speed increases, the profile of the redox peak is well maintained, and rapid ion and electron transport is shown, giving Cu-Ni-S superior rate capability.

Fig. 4 is a constant current charge and discharge (GCD) diagram of the spherical Cu-Ni-S composite nanomaterial prepared in example 1 at different current densities, showing the time-potential relationship of the Cu-Ni-S electrode, and the definite potential platform and its symmetrical shape show the highly reversible oxidation epoxy reaction of the electrode material during charge and discharge, highlighting coulombic efficiency and pseudocapacitance behavior.

FIG. 5 is an impedance spectroscopy (EIS) of a spherical Cu-Ni-S composite nanomaterial electrode, from which it can be seen that the impedance spectroscopy in the low frequency region illustrates that the Cu-Ni-S electrode has a large linear slope, revealing a low diffusion limitation during redox, which is associated with a rough spherical structure of the material surface.

FIG. 6 shows the current density at 10A g^-1The circulation life chart of 10000 times of circulation spherical Cu-Ni-S composite nano material electrode shows the good reversibility of the material. As can be seen from the cycle chart of the electrode material, when the current density is 10A g^-1The specific capacitance of the spherical Cu-Ni-S composite material is 8.5mAh g^-1And simultaneously has excellent conductivity and cycle stability.

Example 2

Dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction for 10 hours at 160 ℃, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Is named CNS-160.

Example 3

Dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction for 10 hours at 200 ℃, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a vacuum oven at 60 ℃ for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Is named CNS-200.

Example 4

Dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 8 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Is named CNS-8 h.

Example 5

Dissolving 0.5mmol of nickel nitrate and 1mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 12 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Named CNS-12 h.

Example 6

Dissolving 0.75mmol of nickel nitrate and 0.75mmol of copper nitrate in 5mL of ethanol, stirring until the nickel nitrate and the copper nitrate are dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene lining kettle, carrying out hydrothermal reaction at 180 ℃ for 10 hours, cooling the product to room temperature, alternately washing the product with deionized water and ethanol, and drying the product in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Named CNS-1: 1.

Example 7 dissolving 1mmol of nickel nitrate and 0.5mmol of copper nitrate in 5mL of ethanol, stirring until dissolved, then adding 0.12mL of carbon disulfide and 1mL of pentamethyldiethylenetriamine, stirring uniformly, transferring the mixture into a 20mL polytetrafluoroethylene-lined kettle, carrying out hydrothermal reaction at 180 ℃ for 10 hours, cooling the product to room temperature, alternately washing with deionized water and ethanol, and drying in a 60 ℃ vacuum oven for 12 hours to obtain the spherical Cu-Ni-S composite nanomaterial. Named CNS-2: 1.

Comparing the SEM characterization maps of fig. 7-12, it can be seen that the experimental parameters affect the morphology of the spherical material, which is specifically shown as: the shape and the agglomeration state of the CNS material are influenced by changing the temperature and the time, the nucleation rate is high when the temperature is high, but the subsequent reaction causes the agglomeration of the material, so that the subsequent material has uneven generated shape. At low temperatures, the material is not uniformly formed as a whole and the spherical surface cannot be uniformly grown. Time affects the material growth size, but too long a time also results in agglomeration of the material, resulting in non-uniformity of the material as a whole. The appearance of the whole material is changed after the proportion of the raw materials is changed, and the growth and nucleation tendency of the material is changed because the composition proportion of the constituent materials is changed.

Compared with fig. 3 and 4, the redox symmetry of the cyclic voltammogram of example 1 is significantly better than that of the remaining examples, and the constant current charge and discharge curve of example 1 shows much higher capacity than that of the remaining examples.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.