阅读说明：本技术 一种单原子锡基复合碳材料及其制备方法和用途 (Monoatomic tin-based composite carbon material and preparation method and application thereof ) 是由 苏发兵 李琼光 于 2021-09-08 设计创作，主要内容包括：本发明提供一种单原子锡基复合碳材料及其制备方法和应用,所述制备方法包括：将锡盐、酚类物质、醛类物质以及溶剂混合,并进行聚合反应；将所述聚合反应的产物进行固液分离,对所得固体进行炭化处理后得到所述单原子锡基复合碳材料。所述制备方法可以使锡成原子级分散于碳材料基体上,所述单原子锡基复合碳材料用于锂离子电池负极材料时,可以提高锂离子电池的可逆容量以及循环寿命。(The invention provides a monoatomic tin-based composite carbon material and a preparation method and application thereof, wherein the preparation method comprises the following steps: mixing tin salt, phenolic substances, aldehyde substances and a solvent, and carrying out polymerization reaction; and carrying out solid-liquid separation on the product of the polymerization reaction, and carrying out carbonization treatment on the obtained solid to obtain the monatomic tin-based composite carbon material. The preparation method can enable tin to be dispersed on a carbon material matrix in an atomic scale, and when the monoatomic tin-based composite carbon material is used for a lithium ion battery cathode material, the reversible capacity and the cycle life of the lithium ion battery can be improved.)

1. A preparation method of a monoatomic tin-based composite carbon material is characterized by comprising the following steps:

mixing tin salt, phenolic substances, aldehyde substances and a solvent, and carrying out polymerization reaction;

and carrying out solid-liquid separation on the product of the polymerization reaction, and carrying out carbonization treatment on the obtained solid to obtain the monatomic tin-based composite carbon material.

2. The method according to claim 1, wherein the tin salt comprises any one of stannous sulfate, stannous chloride or stannic chloride or a combination of at least two of them;

preferably, the phenolic substance comprises any one of phenol, aminophenol or nitrophenol or a combination of at least two thereof;

preferably, the aldehyde substance comprises any one or a combination of at least two of formaldehyde, propionaldehyde, butyraldehyde or valeraldehyde;

preferably, the solvent is water.

3. The method according to claim 1 or 2, wherein the mass ratio of the tin salt to the total mass of the phenolic substance and the aldehyde substance is 1:5 to 100, preferably 1:5 to 20;

preferably, the mass volume ratio of the tin salt to the solvent is 1: 0.2-4.0 mg/mL.

4. The method according to any one of claims 1 to 3, wherein the polymerization reaction temperature is 10 to 35 ℃;

preferably, the time of the polymerization reaction is 0.5-6 h, and preferably 3-6 h.

5. The production method according to any one of claims 1 to 4, wherein the solid-liquid separation comprises any one of atmospheric filtration, suction filtration, or centrifugation, or a combination of at least two thereof;

preferably, the solid obtained after the solid-liquid separation is dried.

6. The preparation method according to any one of claims 1 to 5, wherein the temperature of the carbonization treatment is 600 to 900 ℃;

preferably, the carbonization treatment time is 1-3 h.

7. The production method according to any one of claims 1 to 6, characterized by comprising:

mixing tin salt, a phenolic substance, an aldehyde substance and water, wherein the mass ratio of the tin salt to the total mass of the phenolic substance and the aldehyde substance is 1: 5-100, the mass-volume ratio of the tin salt to the water is 1: 0.2-4.0 mg/mL, and carrying out polymerization reaction at 10-35 ℃ for 0.5-6 h;

and carrying out solid-liquid separation on the product of the polymerization reaction, and carrying out carbonization treatment on the dried solid at 600-900 ℃ for 1-3 h to obtain the monatomic tin-based composite carbon material.

8. A monoatomic tin-based composite carbon material produced by the production method according to any one of claims 1 to 7.

9. The monatomic tin-based composite carbon material according to claim 8, wherein the monatomic tin content is 1.0 to 20.0 wt%;

preferably, the shape of the monoatomic tin-based composite carbon material is spherical;

preferably, the particle size of the monoatomic tin-based composite carbon material is 200 to 1000nm, and preferably 400 to 600 nm.

10. Use of the monatomic tin-based composite carbon material according to claim 8 or 9 for producing a negative electrode material for a lithium ion battery.

Technical Field

The invention belongs to the field of composite materials, relates to a composite carbon material, and particularly relates to a monoatomic tin-based composite carbon material, and a preparation method and application thereof.

Background

Lithium ion batteries have been widely used in many areas of daily life, such as 3C products, electric vehicles, and the like. Conventional anode materials represented by graphite anodes have failed to satisfy the demand for higher energy density, and therefore, it is necessary to develop new anode materials having higher capacity density. Tin base negativeThe electrode material has a g of up to 994mAh^-1And a suitable operating voltage (0.6V vs. Li/Li)⁺) Arouse people's extensive attention. However, in the lithium insertion process, tin particles generate huge volume expansion, and further a series of problems of particle crushing, electrode structure pulverization and shedding, loss of electric contact with a current collector and the like are caused, rapid capacity attenuation is shown, and even a battery safety problem is caused. Meanwhile, the elemental tin material has poor conductivity, which affects the rate capability. The above problems severely limit the development of tin-based anode materials.

The tin/carbon composite strategy is considered to be a method which can effectively relieve the problems of volume expansion, poor conductivity and the like of tin-based materials. CN112794305A discloses a preparation method of a hollow carbon nanosphere confinement tin nanocluster composite material, which utilizes a polymerization reaction to confine tin nanoclusters in hollow carbon nanospheres. The nano tin metal material is beneficial to relieving the volume expansion problem of the material, and the hollow carbon nanosphere framework is beneficial to improving the conductivity of the material. CN112928266A discloses a preparation method of a graphene-coated nano-porous tin composite material, which takes a tin-magnesium alloy and graphene oxide as raw materials, and obtains the graphene-coated nano-porous tin composite material through in-situ reduction and selective etching steps. Due to the existence of the graphene coating layer, the conductivity of the material is improved, and meanwhile, the volume expansion of the tin anode material is relieved. In addition, CN112436127A discloses a method for preparing a nano-structured tin/carbon composite material by using citrate and stannous salt as raw materials, and patent CN112599738A discloses a method for preparing a tin nanosphere/three-dimensional mesoporous carbon composite material. The nano-compounding strategy alleviates the above problems only to a certain extent and is not a very effective approach.

The tin-based composite material with atomic-level dispersion can effectively solve the problem of serious volume expansion of particles in the lithium intercalation process, and can improve the conductivity of the material by utilizing a carbon skeleton structure. Zhang et al (National Science view 2020,7:600-608) report a method for preparing CuO loaded Zn-Sn monoatomic pair composite material, copper salt and tin salt are firstly dissolved in ice bath to form uniform solution, alkali liquor is added, then the steps of refrigeration, hydrothermal treatment, washing, drying and the like are carried out to obtain Sn/CuO composite material, then Sn/CuO is dispersed in ethanol solution, aqueous solution of tin salt is slowly added, and then the steps of ageing, filtering, washing, drying, calcining and the like are carried out to finally obtain CuO loaded Zn-Sn monoatomic pair composite material. Chou et al (Angew. chem. int. Ed.2020,59, 22171-22178) reported a general synthesis strategy of a single-atom catalyst, slowly adding a hydrochloric acid solution containing CTAB, pyrrole and P-TSNa into an ammonium persulfate solution, reacting at 0-5 ℃ for 24h, filtering out precipitates, washing and vacuum drying to obtain an S-PPy material, ultrasonically dispersing the S-PPy material into an ethanol solution, adding a metal salt, stirring until the ethanol is completely volatilized, and finally carbonizing to obtain a single-atom composite carbon material, including V, Mn, Fe, Co, Ni, Cu, Ge, Mo, Ru, Rh, Pd, Ag, In, Sn, W, Ir, Pt, Pb, Bi and the like. The monatomic material reported in the above documents has a complex preparation process, harsh conditions and high process cost, and cannot meet the industrial application requirements of the monatomic material. In addition, there has been no report on a monoatomic composite carbon material as a negative electrode material for a lithium ion battery so far. Therefore, it is urgently needed to develop a method for preparing a monoatomic tin-based material which is simple in process, low in cost and capable of being produced in a large scale, and to use the monoatomic tin-based material as a negative electrode material of a high-energy-density lithium ion battery.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a monoatomic tin-based composite carbon material, and a preparation method and application thereof.

In order to achieve the technical effect, the invention adopts the following technical scheme:

one of the purposes of the invention is to provide a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing tin salt, phenolic substances, aldehyde substances and a solvent, and carrying out polymerization reaction;

and carrying out solid-liquid separation on the product of the polymerization reaction, and carrying out carbonization treatment on the obtained solid to obtain the monatomic tin-based composite carbon material.

In the invention, the preparation method can lead Sn to be in an atomic-scale dispersion form and to be dispersed on carbon spheres derived from phenolic resin, and can be used for high-energy-density lithium ion battery cathode materials. During carbonization, the monoatomic Sn, O and C or N can form a coordination structure, so that the Sn atoms are prevented from being aggregated into nanoparticles.

As a preferred embodiment of the present invention, the tin salt includes any one of stannous sulfate, stannous chloride or stannic chloride or a combination of at least two of them, and typical but non-limiting examples are: combinations of stannous sulfate and stannous chloride, stannous chloride and stannous tetrachloride, stannous tetrachloride and stannous sulfate, or stannous sulfate, stannous chloride and stannous tetrachloride, and the like.

Preferably, the phenolic material comprises any one of phenol, aminophenol or nitrophenol, or a combination of at least two of the following typical but non-limiting examples: combinations of phenol and aminophenol, aminophenol and nitrophenol, nitrophenol and phenol, or phenol, aminophenol and nitrophenol, and the like.

Preferably, the aldehyde substance comprises any one of formaldehyde, propionaldehyde, butyraldehyde or valeraldehyde or a combination of at least two of these, typical but non-limiting examples being: combinations of formaldehyde and propionaldehyde, propionaldehyde and butyraldehyde, butyraldehyde and valeraldehyde, valeraldehyde and formaldehyde, or formaldehyde, propionaldehyde and butyraldehyde, and the like.

Preferably, the solvent is water.

In a preferred embodiment of the present invention, the mass ratio of the tin salt to the total mass of the phenolic substance and the aldehyde substance is 1:5 to 100, for example, 1:10, 1:15, 1:20, 1:25, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, or 1:90, but the tin salt is not limited to the above-mentioned values, and other values not listed in the above-mentioned value range are also applicable, and preferably 1:5 to 20.

Preferably, the mass-to-volume ratio of the tin salt to the solvent is 1:0.2 to 4.0mg/mL, such as 1:0.2mg/mL, 1:0.4mg/mL, 1:0.8mg/mL, 1:1.6mg/mL, 1:4.0mg/mL, and the like, but is not limited to the recited values, and other values not recited within this range are equally applicable.

In a preferred embodiment of the present invention, the polymerization temperature is 10 to 35 ℃, for example, 12 ℃, 15 ℃, 18 ℃, 20 ℃,22 ℃, 25 ℃, 28 ℃, 30 ℃, 32 ℃ or 34 ℃, but the polymerization temperature is not limited to the recited values, and other values not recited in the above range are also applicable.

Preferably, the polymerization time is 0.5 to 6 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or 5.5 hours, but not limited to the recited values, and other values not recited within the range of values are also applicable, preferably 3 to 6 hours.

As a preferable technical scheme of the invention, the solid-liquid separation comprises any one or the combination of at least two of normal pressure filtration, suction filtration and centrifugation.

Preferably, the solid obtained after the solid-liquid separation is dried.

In a preferred embodiment of the present invention, the temperature of the carbonization treatment is 600 to 900 ℃, for example, 650 ℃, 700 ℃, 750 ℃, 800 ℃ or 850 ℃, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.

Preferably, the carbonization time is 1 to 3 hours, such as 1.2 hours, 1.5 hours, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours or 2.8 hours, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In the present invention, the carbonization treatment may be carried out in a tube furnace, a fixed bed or a fluidized bed.

As a preferable technical solution of the present invention, the preparation method of the monatomic tin-based composite carbon material includes:

mixing tin salt, a phenolic substance, an aldehyde substance and water, wherein the mass ratio of the tin salt to the total mass of the phenolic substance and the aldehyde substance is 1: 5-100, the mass-volume ratio of the tin salt to the water is 1: 0.2-4.0 mg/mL, and carrying out polymerization reaction at 10-35 ℃ for 0.5-6 h;

and carrying out solid-liquid separation on the product of the polymerization reaction, and carrying out carbonization treatment on the dried solid at 600-900 ℃ for 1-3 h to obtain the monatomic tin-based composite carbon material.

The second object of the present invention is to provide a monoatomic tin-based composite carbon material prepared by the preparation method provided in the first aspect.

In a preferred embodiment of the present invention, the content of the monoatomic tin is 1.0 to 20.0 wt%, for example, 2.0 wt%, 5.0 wt%, 8.0 wt%, 10.0 wt%, 12.0 wt%, 15.0 wt%, or 18.0 wt%, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.

In the present invention, the monoatomic tin-based composite carbon material contains a nitrogen element, an oxygen element, and the like in addition to a tin element and a carbon element.

Preferably, the shape of the monoatomic tin-based composite carbon material is spherical.

Preferably, the monoatomic tin-based composite carbon material has a particle size of 200 to 1000nm, such as 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, and the like, but is not limited to the enumerated values, and other values within the range are also applicable, and preferably 400 to 600 nm.

In the monatomic tin-based composite carbon material provided by the invention, the content of the Sn component and the particle size can be regulated and controlled within a certain range, and when the monatomic tin-based composite carbon material is used as a negative electrode material of a lithium ion battery, the monatomic tin-based composite carbon material has high reversible capacity and good cycle performance.

The invention also aims to provide application of the monatomic tin-based composite carbon material provided by the second aspect in preparation of a lithium ion battery negative electrode material.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) the invention provides a preparation method of a monoatomic tin-based composite carbon material, which can ensure that tin is atomically dispersed on a carbon material matrix, and the preparation method has the advantages of simple process, low cost, easy implementation and large-scale production;

(2) the invention provides a monoatomic tin-based composite carbon material which can be used as a high-energy-density lithium ion battery cathode material, and can improve the reversible capacity and cycle life of a lithium ion battery.

Drawings

FIG. 1 is a HAADF-STEM diagram of a monoatomic tin-based composite carbon material prepared in example 1 of the present invention;

FIG. 2 is an SEM image of a monatomic tin-based composite carbon material prepared in example 1 of the present invention;

FIG. 3 shows the single-atom tin-based composite carbon material obtained in example 1 of the present invention and the nano-particle tin-based composite carbon materials obtained in comparative examples 1 and 2 at 1000mA g^-1Cycling performance plot at current density.

The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.

Detailed Description

To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows:

example 1

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.2g of stannous chloride, 1.0g of aminophenol and 80mL of deionized water, adding 1.0g of formaldehyde solution, and carrying out polymerization reaction for 3 hours at 25 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the monoatomic tin-based composite carbon material, wherein the load Sn content is 10.0 wt%, and the particle size distribution is 350-450 nm.

The prepared monoatomic tin-based composite carbon material is analyzed and tested, and the method specifically comprises the following steps:

(1) single atom test analysis: the monoatomic tin-based composite carbon material prepared as described above was characterized by a transmission electron microscope model JEOL JEM-ARM200F, manufactured by JEOL Ltd., as shown in FIG. 1. As can be seen from fig. 1, no Sn nanoparticles or Sn clusters are shown on the carbon nanoball, and the bright spots of the individual Sn atoms marked by white circles are uniformly dispersed, confirming that Sn exists as isolated individual atoms.

(2) And (3) morphology analysis: the monoatomic tin-based composite carbon material prepared above was characterized by using a JSM6700 type field emission scanning electron microscope produced by japan electronics, as shown in fig. 2. As can be seen from FIG. 2, the monoatomic tin-based composite carbon material prepared by the method is spherical particles, and the particle size distribution is 350-450 nm.

(3) And (3) electrochemical performance testing: the obtained material is applied to the preparation of a lithium ion battery, and the preparation method comprises the following steps of: conductive carbon black: binder 70: 20: 10, coating the mixture on a copper foil current collector after mixing the mixture with deionized water as a solvent, and assembling the button type half cell after vacuum drying and slicing at 120 ℃. The charge and discharge test is carried out on a NEWARE BTS-5V/10mA type charge and discharge tester produced by New Wille electronics Limited in Shenzhen, the test method of other embodiments is the same as that of the embodiment, and the test result is shown in FIG. 3. As can be seen from FIG. 3, at 1000mA g^-1After 10000 times of circulation under the current density, the discharge capacity is 261mAh g^-1The monoatomic tin-based composite carbon material obtained in example 1 shows higher reversible capacity and good cycle stability.

Example 2

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.2g of stannous chloride, 1.0g of nitrophenol and 80mL of deionized water, adding 1.0g of formaldehyde solution, and carrying out polymerization reaction for 2 hours at 20 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 700 ℃ for 1h to obtain the monatomic tin-based composite carbon material, wherein the supported Sn content is 15.0 wt%, and the particle size distribution is 300-400 nm.

Example 3

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.1g of stannous chloride, 1.0g of phenol and 80mL of deionized water, adding 1.0g of formaldehyde solution, and carrying out polymerization reaction at 30 ℃ for 0.5 h;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 800 ℃ for 3 hours to obtain the monoatomic tin-based composite carbon material, wherein the load Sn content is 8.0 wt%, and the particle size distribution is 200-300 nm.

Example 4

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.05g of stannous chloride, 1.0g of aminophenol and 80mL of deionized water, adding 1.0g of propionaldehyde solution, and carrying out polymerization reaction for 6 hours at 15 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 900 ℃ for 1h to obtain the monatomic tin-based composite carbon material, wherein the load Sn content is 5.0 wt%, and the particle size distribution is 800-1000 nm.

Example 5

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.02g of stannous sulfate, 1.0g of nitrophenol and 80mL of deionized water, adding 1.0g of butyraldehyde solution, and carrying out polymerization reaction for 1h at 25 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 900 ℃ for 3 hours to obtain the monoatomic tin-based composite carbon material, wherein the load Sn content is 1.0 wt%, and the particle size distribution is 250-350 nm.

Example 6

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.02g of stannous sulfate, 1.0g of aminophenol and 80mL of deionized water, adding 1.0g of propionaldehyde solution, and carrying out polymerization reaction for 6 hours at 15 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 600 ℃ for 1h to obtain the monoatomic tin-based composite carbon material, wherein the supported Sn content is 2.0 wt%, and the particle size distribution is 800-1000 nm.

Example 7

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.4g of stannic chloride, 1.0g of phenol and 80mL of deionized water, adding 1.0g of valeraldehyde solution, and carrying out polymerization reaction for 3h at 25 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the monoatomic tin-based composite carbon material, wherein the supported Sn content is 20.0 wt%, and the particle size distribution is 350-450 nm.

Example 8

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.1g of stannous chloride, 1.0g of aminophenol and 80mL of deionized water, adding 1.0g of valeraldehyde solution, and carrying out polymerization reaction for 5 hours at 20 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 800 ℃ for 2 hours to obtain the monoatomic tin-based composite carbon material, wherein the load Sn content is 6.0 wt%, and the particle size distribution is 700-900 nm.

Example 9

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.2g of stannous sulfate, 1.0g of nitrophenol and 80mL of deionized water, adding 1.0g of butyraldehyde solution, and carrying out polymerization reaction for 4 hours at 25 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 700 ℃ for 1h to obtain the monoatomic tin-based composite carbon material, wherein the load Sn content is 11.0 wt%, and the particle size distribution is 550-650 nm.

Example 10

The embodiment provides a preparation method of a monoatomic tin-based composite carbon material, which comprises the following steps:

mixing 0.3g of stannic chloride, 1.0g of nitrophenol and 80mL of deionized water, adding 1.0g of propionaldehyde solution, and carrying out polymerization reaction for 2 hours at 30 ℃;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 700 ℃ for 2 hours to obtain the monoatomic tin-based composite carbon material, wherein the supported Sn content is 13.0 wt%, and the particle size distribution is 250-350 nm.

Comparative example 1

In this comparative example, 1.0g aminophenol and 80mL deionized water were mixed and 1.0g propionaldehyde solution was added and polymerization was carried out at 25 ℃ for 3 hours;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the carbon material which does not contain Sn and has the particle size distribution of 350-450 nm.

Comparative example 2

In this comparative example, 0.2g of tin dioxide, 1.0g of aminophenol and 80mL of deionized water were mixed, 1.0g of formaldehyde solution was added, and polymerization was carried out at 25 ℃ for 3 hours;

and filtering the product of the polymerization reaction, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the nano-particle tin dioxide-based composite carbon material, wherein the supported Sn content is 10.0 wt% (same as that in example 1), and the particle size distribution is 350-450 nm.

Comparative example 3

1.0g of aminophenol is dissolved in 80mL of deionized water, then 1.0g of formaldehyde solution is added, and polymerization reaction is carried out for 3 hours at 25 ℃;

and filtering the product of the polymerization reaction, uniformly mixing the dried solid with 0.2g of stannous chloride, and carbonizing at 600 ℃ for 2 hours to obtain the tin-based composite carbon material, wherein the load Sn amount is 10.0 wt%.

Comparative example 4

Adding 0.25g of stannous chloride and 2.0g of activated carbon into 80mL of deionized water, and stirring for 3h at 25 ℃;

and filtering the stirred product, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the tin-based composite carbon material with the load Sn of 10.0 wt%.

Comparative example 5

Adding 0.2g of stannous chloride and 2.0g of commercial graphite into 80mL of deionized water, and stirring for 3h at 25 ℃;

and filtering the stirred product, and carbonizing the dried solid at 600 ℃ for 2 hours to obtain the monatomic tin-based composite carbon material with the load Sn of 2.0 wt%.

In order to examine the electrochemical performance of the monatomic tin-based composite carbon material provided by the invention as a negative electrode material of a lithium ion battery, the monatomic tin-based composite carbon material obtained in examples 1 to 10, the carbon material obtained in comparative example 1, the composite material prepared in comparative examples 2 to 5 and a commercial graphite negative electrode material are assembled and tested in a button half cell under the same conditions, and the assembling and testing method specifically comprises the following steps: according to the active substance: conductive carbon black: binder 70: 20: 10, coating the mixture on a copper foil current collector after mixing the mixture with deionized water as a solvent, and assembling the button type half cell after vacuum drying and slicing at 120 ℃. The charge and discharge test is carried out on a NEWARE BTS-5V/10mA type charge and discharge tester produced by New Wille electronics Limited in Shenzhen, and the test results are shown in Table 1.

TABLE 1

The data presented in table 1 are experimental data obtained under the same test environment and for button cell assembly under the same conditions, and the differences in reversible capacity of the materials prepared in the examples are mainly due to the differences in tin content in the materials. The first week discharge capacity and the discharge capacity after 100 weeks for examples 1-10 were significantly higher than comparative example 1 (without tin) and the commercial graphite anode material; the monatomic tin-based composite carbon material obtained in example 1 had the same Sn content as the nanoparticle tin dioxide-based composite carbon material obtained in comparative example 2, but the first-week discharge capacity and the discharge capacity after 100 weeks of the former were significantly higher than the latter, and the monatomic tin-based composite carbon material obtained in example 1 had the same Sn content as the tin-based composite carbon materials obtained in comparative examples 3 and 4, but the first-week discharge capacity and the discharge capacity after 100 weeks of the former were significantly higher than the latter; the data of example 1, in which a monoatomic tin-based composite material supporting 10.0 wt% of Sn was obtained and a tin-based composite material supporting 2.0 wt% of Sn was obtained through the latter, were significantly higher than those of the latter, when the preparation of the tin-based composite carbon material was performed under the same conditions as in comparative example 5, indicating that the monoatomic tin-based composite carbon material had significant advantages.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.