CN112993224A - Cross-linked chitosan derived silicon-carbon negative electrode material and preparation method thereof - Google Patents

Cross-linked chitosan derived silicon-carbon negative electrode material and preparation method thereof Download PDF

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CN112993224A
CN112993224A CN202110171259.2A CN202110171259A CN112993224A CN 112993224 A CN112993224 A CN 112993224A CN 202110171259 A CN202110171259 A CN 202110171259A CN 112993224 A CN112993224 A CN 112993224A
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silicon
chitosan
negative electrode
carbon
electrode material
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张贤
杨宇航
丁瑜
王�锋
付争兵
杜军
杨雄
余链
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Hubei Engineering University
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    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
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Abstract

The invention discloses a crosslinked chitosan derived silicon-carbon negative electrode material and a preparation method thereof, wherein the preparation method comprises the following steps: adding acetic acid into deionized water to form an acetic acid solution, adding chitosan, stirring, adding nano silicon powder after full dissolution, stirring under an ultrasonic state to uniformly disperse the nano silicon powder, adding or adding a proper amount of nano carbon material as a conductive agent, then dropwise adding a crosslinking agent to form silicon-containing chitosan gel, and removing the solvent to obtain a crosslinked chitosan-coated nano silicon precursor; the crosslinked chitosan-coated nano silicon precursor is subjected to pre-oxidation in air and high-temperature heat treatment in an inert atmosphere to obtain the crosslinked chitosan-derived silicon-carbon negative electrode material. The invention has the characteristics of simple and easily obtained raw materials, simple process, shorter preparation period, stable structure of the prepared silicon-carbon anode material, good electrochemical performance and the like.

Description

Cross-linked chitosan derived silicon-carbon negative electrode material and preparation method thereof
Technical Field
The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a crosslinked chitosan coated nano silicon-derived silicon-carbon cathode material and a preparation method thereof.
Background
At present, graphite negative electrode materials are widely adopted by lithium ion batteries, and the theoretical specific capacity of the lithium ion batteries is only 372mAh & g-1The graphite cathode material with better performance on the market can reach 360 mAh.g-1The specific capacity gradually approaches to the limit value, and higher requirements are difficult to meet. The theoretical specific capacity of silicon is up to 4200mAh g-1The embedded lithium potential is lower than 0.5V, the mass abundance in the crust is as high as 26.3 percent, and the material is environment-friendly and is a main candidate material for the next generation of lithium ion battery cathode material. However, the huge volume effect of silicon during charging and discharging can cause electrode pulverization and form unstable SEI film, which causes the rapid attenuation of battery capacity and hinders the commercialization process thereof. The nano-crystallization of the silicon material can slow down the volume effect to a certain extent, so that the ion transmission distance is shortened, and the polarization is reduced, but the improvement effect is not obvious due to the agglomeration of nano-silicon particles. The negative electrode material prepared by compounding silicon and carbon can prevent the nano silicon from agglomerating and maintain the dispersibility of the nano silicon. In addition, the good carbon coating can also reduce direct contact of silicon materials and electrolyte, inhibit excessive growth of SEI (solid electrolyte interphase), stabilize an interface and reduce the quantity and speed of lithium ions embedded into silicon particles, thereby greatly slowing down the volume efficiency of the materialsShould be used. Therefore, the silicon-carbon composite material can fully exert the high specific capacity of the silicon material and the high stability of the carbon material. (Shen X, Tian Z, Fan R, et al].Journal of Energy Chemistry,2018,27(4):1067-1090.)。
The silicon-carbon composite material consists of a silicon source and a carbon source, the two parts are combined according to a certain structure by process design, and the ideal silicon-carbon composite material can highly and uniformly disperse silicon nanoparticles in a structure taking carbon as a shell or a framework. The coal tar pitch silicon/carbon composite can be prepared by adopting nano silicon as a silicon source and coal tar pitch with low softening point and high carbon residue rate as a carbon source through a two-step coating method, wherein silicon nanoparticles are coated by carbon and mutually connected to form a C-Si-C network structure, and the silicon/carbon composite with 27 percent of silicon content shows good lithium storage performance as a lithium battery electrode material (Wangjinying, Qujiang English, Lijilan, and the like. the coal tar pitch silicon/carbon composite prepared by the secondary coating method and the lithium ion battery performance [ J ] of the coal tar pitch silicon/carbon composite are applied to chemistry 2020,37(5): 562-. The nano-structure silicon/porous carbon spherical composite material prepared by a hydrothermal method and a soft template method in the presence of silicon nanoparticles by using glucose as a carbon source and using a polybasic F127 as a pore-forming agent has a nano-scale porous carbon shell and good electrochemical dynamic performance (Shao D, Tang D, Mai Y, et al. nanostructured silicon/porous carbon composite as a high performance anode for Li-ion batteries [ J ]. Journal of Materials Chemistry A,2013,1(47): 15068-15075.). In addition, the polystyrene-polyvinylpyrrolidone mixed polymer solution containing silicon nanoparticles, Carbon nanotubes and Carbon black is prepared by an electrospray method and is subjected to heat treatment to obtain the silicon-embedded Carbon microspheres with ion and electron conductive frameworks, which can effectively relieve the volume expansion of silicon and can also accelerate the transmission speed of ions and electrons (Liang G, Qin X, Zou J, et al. electrophoretic silicon-embedded pores as ions-ion substrates and ions with exclusion rates of nanoparticles [ J ]. Carbon,2018,127:424 and 431.).
The method for preparing the silicon-carbon composite material respectively uses asphalt, glucose and polystyrene-polyvinylpyrrolidone as carbon sources, and has the following defects: the reaction process route is complex, pore-forming agent and other auxiliary agents are required to be added, and the preparation cost is high. In addition, the prepared silicon material still has a relatively serious volume effect, so that the early-stage specific capacity is relatively high, the initial coulombic efficiency is relatively low, the attenuation speed is relatively high, and the commercial application value is not high. Therefore, in order to overcome the defects of the existing preparation process, the silicon-carbon composite material with low preparation cost, simple process and excellent performance is developed, and the silicon-carbon composite material has important significance for promoting the application of the silicon-carbon negative electrode material in the lithium ion battery.
The high-dispersity nano silicon powder is uniformly wrapped by adopting a three-dimensional network structure, so that the performance of the silicon-carbon composite material can be greatly improved. Chitosan is an abundant natural polysaccharide compound, can be derived into a nitrogen-rich carbon material through heat treatment, and is a promising carbon source. In addition, the chitosan also has strong adhesive capacity, can effectively disperse the nano silicon powder, has relatively high nitrogen content (more than 7 percent), and is favorable for improving the conductivity of the carbon material by adding the nitrogen element. However, when the chitosan is directly mixed with the nano silicon powder, in the process of removing the solvent, the chitosan molecules shrink, so that the local dispersion of the silicon-carbon material is easily caused, the high dispersibility of the silicon-carbon material is lost, and the electrochemical performance of the prepared composite material needs to be further improved. If the high dispersion state of the chitosan and the nano silicon particles in the solution can be maintained, the electrochemical performance of the silicon-carbon composite material can be greatly improved.
Disclosure of Invention
The invention aims to provide a preparation method of a cross-linked chitosan derived silicon-carbon negative electrode material, which has the advantages of simple and easily obtained raw materials, simple process, low cost and environmental protection.
The invention also provides the crosslinked chitosan derived silicon-carbon negative electrode material prepared by the preparation method, and silicon is uniformly dispersed in the carbon material, and has a stable structure and good electrochemical performance.
The invention also provides the application of the cross-linked chitosan derived silicon-carbon negative electrode material in a lithium ion battery negative electrode material, the first coulombic efficiency is higher than 60%, the discharge specific capacity in the early stage of charge-discharge cycle is slowly increased, the later decay is slow, and the cross-linked chitosan derived silicon-carbon negative electrode material has a good application prospect.
In order to further achieve the purpose, the invention adopts the following technical scheme: a preparation method of a cross-linked chitosan derived silicon-carbon negative electrode material comprises the following steps:
adding acetic acid into deionized water to form an acetic acid solution, adding chitosan, stirring, adding nano silicon powder after full dissolution, stirring for 1-4 h under the ultrasonic condition of 40-100 kHz to obtain a silicon-containing chitosan solution with high uniform dispersion, then adding or adding a proper amount of nano carbon material as a conductive agent, adding a certain amount of cross-linking agent after uniform dispersion, continuing stirring for a period of time until stirring is stopped, and standing for a period of time to form stable cross-linked chitosan-coated nano silicon powder gel. And then, freeze-drying, namely, putting the sample (the crosslinked chitosan coated nano silicon powder gel) into a low-temperature freezer for freezing for 24 hours, putting the sample into a vacuum freeze-drying machine, and freeze-drying for 24-48 hours under the conditions of cold hydrazine at the temperature of-50 ℃ and the pressure of 1-10 Pa to prepare the crosslinked chitosan coated nano silicon precursor.
And pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor in the air at a certain temperature for a period of time, heating to a certain temperature at a heating rate of 5 ℃/min in an inert atmosphere, keeping at the temperature for a period of time, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon negative electrode material.
The key steps in the specific steps comprise the following aspects: (1) and (3) performing crosslinking treatment on the chitosan. The high dispersibility of silicon in chitosan molecules can be maintained, and a foundation is laid for preparing a negative electrode material with good performance; (2) and (5) freeze drying. The three-dimensional network structure of the silicon-containing chitosan can be fully maintained, and a compact agglomeration structure cannot be formed due to shrinkage in the thermal drying process; (3) and pre-oxidizing the cross-linked chitosan coated nano-silicon precursor. If the pre-oxidation treatment is not carried out, the high-temperature treatment is directly carried out in the inert atmosphere, the nano silicon powder in the pyrolysis product can be oxidized into silicon dioxide, and the good electrochemical performance is lost.
In the invention, the molecular weight of the chitosan is 1-60 ten thousand, and the deacetylation degree is more than or equal to 70%; the particle size of the nano silicon powder is 10-100 nm.
In the invention, the conductive agent is one or more of water-soluble asphalt, graphene, a carbon nanotube and conductive carbon black.
In the invention, the cross-linking agent is one of glutaraldehyde and glyoxal.
In the invention, the mass ratio of the water, the acetic acid, the chitosan, the nano silicon powder, the conductive agent and the cross-linking agent is 500: 5-10: 1-10: 0-2: 1-5.
In the invention, the pre-oxidation treatment temperature range is 200-300 ℃, and the heat preservation time is 1-8 h.
In the invention, the temperature range of the inert atmosphere heat treatment is 600-1200 ℃, and the heat preservation time is 1-4 h.
Correspondingly, the invention also provides a crosslinked chitosan derived silicon-carbon negative electrode material which is prepared by using the preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material.
According to the cross-linked chitosan derived silicon-carbon cathode material obtained by the preparation method, the nano silicon powder is highly and uniformly dispersed in the cross-linked chitosan derived carbon material, the high capacity of silicon and the high stability of carbon can be fully exerted, the capacity is slowly increased in the early stage, the later attenuation rate is obviously lower than that of a silicon-carbon composite material prepared by the prior art, and the first coulombic efficiency is higher.
Correspondingly, the invention also provides application of the crosslinked chitosan derived silicon-carbon negative electrode material in a lithium ion battery negative electrode material, wherein a lithium sheet is taken as a counter electrode to assemble a CR2016 type lithium ion button battery, and then the electrochemical performance of the CR2016 type lithium ion button battery is tested.
Due to the adoption of the technical scheme, compared with the prior art, the invention has the following positive effects:
the invention highly disperses chitosan and nano silicon powder, then adds cross linker, carries out cross linking reaction under room temperature, aldehyde groups at two ends of glutaraldehyde react with amino groups on chitosan molecules respectively, thereby connecting chitosan, converting linear long chain structure into three-dimensional network structure, nano silicon particles dispersed on the surface of chitosan molecules are encapsulated by the network structure, thereby firmly locking the nano silicon particles in the chitosan molecules, then adopts freeze drying to remove solvent, obtains silicon-carbon composite precursor with high dispersibility and high stability, and finally carries out pre-oxidation treatment and high temperature heat treatment under inert atmosphere, thus obtaining the silicon-carbon composite material with good electrochemical performance.
The preparation process route of the crosslinked chitosan coated nano silicon precursor is simple and convenient, a dispersing agent and a pore-forming agent are not required to be added, the crosslinking agent is added, the reaction is rapidly completed at room temperature, and the silicon-carbon precursor can be prepared after freeze drying; and then, the sample is subjected to pre-oxidation treatment in the air, so that the structure of the polymer is stabilized, and the problems of structure collapse and silicon oxidation cannot occur in the subsequent high-temperature heat treatment under the inert atmosphere.
According to the invention, through electrochemical tests, the first coulombic efficiency of the prepared silicon-carbon negative electrode material exceeds 60%, the discharge specific capacity tends to increase in a small range in the early charging and discharging cycle process, and the later discharge specific capacity is slowly attenuated, so that the effects of high specific capacity and high stability are fully realized.
The invention has the characteristics of simple and easily obtained raw materials, simple process, shorter preparation period, stable structure of the prepared silicon-carbon anode material, good electrochemical performance and the like.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:
FIG. 1 is an XRD spectrum of a cross-linked chitosan coated nano-silicon precursor (Si @ CTS) and a silicon-carbon negative electrode material (Si @ C) prepared in example 1 of the present invention;
fig. 2 is SEM images of the cross-linked chitosan-coated nano-silicon precursor (a) and the silicon-carbon negative electrode material (b) prepared in example 1 of the present invention;
FIG. 3 is a coulombic efficiency curve of the silicon-carbon negative electrode material prepared in the embodiments 1-6 of the present invention under a current of 0.1A;
fig. 4 is a discharge specific capacity curve of the silicon-carbon negative electrode material prepared in embodiments 1 to 6 of the present invention at a current of 0.1A.
Detailed Description
In order to make the aforementioned features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below, without limiting the present invention in any way.
Example 1.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 10 parts of acetic acid to form an acetic acid solution, adding 10 parts of chitosan with the molecular weight of 10 ten thousand and the deacetylation degree of 95%, stirring for dissolving, adding 4 parts of silicon powder with the particle size of 20-60 nm after fully dissolving, stirring for 1h under the ultrasonic state of 100kHz to uniformly disperse the silicon powder, adding no conductive agent as a contrast group, adding 3 parts of glutaraldehyde as a crosslinking agent, continuously stirring for a period of time until the mixture cannot be stirred, and standing for a period of time to form stable crosslinked chitosan-coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 48 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent to obtain the crosslinked chitosan coated nano-silicon precursor.
Pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor in air at 280 ℃ for 2h, then heating to 1000 ℃ at the heating rate of 5 ℃/min in inert atmosphere, preserving heat for 2h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon cathode material.
Fig. 1 is an XRD spectrogram of example 1, which shows that silicon in the prepared precursor and the final product maintains stable structure, and the diffraction peak intensity of silicon is significantly reduced compared to pure nano-silicon powder, indicating that silicon is uniformly coated with cross-linked chitosan and a derived carbon material. FIG. 2 is an SEM photograph of example 1, in which highly reflective nanoparticles are silicon particles, and it can be seen from the microstructure of the precursor (FIG. 2a) that the silicon nanoparticles are uniformly coated with crosslinked chitosan; the prepared silicon-carbon anode material (figure 2b) has a similar structure except that a large number of fine pores are formed.
Example 2.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 5 parts of acetic acid to form an acetic acid solution, adding 5 parts of chitosan with the molecular weight of 20 ten thousand and the deacetylation degree of 90%, stirring for dissolving, adding 6 parts of silicon powder with the particle size of 10-20 nm after fully dissolving, stirring for 2 hours under the ultrasonic state of 90kHz to uniformly disperse the silicon powder, adding 0.2 part of conductive carbon black as a conductive agent, adding 1 part of glyoxal as a crosslinking agent, continuously stirring for a period of time until the stirring is stopped after being failed, and standing for a period of time to form stable crosslinked chitosan-coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 36 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent to obtain the crosslinked chitosan coated nano-silicon precursor.
And pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor for 3h at 260 ℃ in the air, heating to 900 ℃ at the heating rate of 5 ℃/min in the inert atmosphere, preserving the temperature for 2.5h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon negative electrode material.
Example 3.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 10 parts of acetic acid to form an acetic acid solution, adding 10 parts of chitosan with the molecular weight of 30 ten thousand and the deacetylation degree of 85%, stirring for dissolving, adding 8 parts of silicon powder with the particle size of 20-40 nm after fully dissolving, stirring for 3 hours under the ultrasonic state of 80kHz to uniformly disperse the silicon powder, adding 1 part of graphene as a conductive agent, adding 2 parts of glutaraldehyde as a crosslinking agent, continuing stirring for a period of time until the mixture cannot be stirred, and standing for a period of time to form stable crosslinked chitosan-coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 24 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent to obtain the crosslinked chitosan coated nano-silicon precursor.
And pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor for 4h at 240 ℃ in air, heating to 800 ℃ at a heating rate of 5 ℃/min in an inert atmosphere, preserving heat for 3h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon negative electrode material.
Example 4.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 5 parts of acetic acid to form an acetic acid solution, adding 5 parts of chitosan with the molecular weight of 40 ten thousand and the deacetylation degree of 80%, stirring for dissolving, adding 10 parts of silicon powder with the particle size of 40-60 nm after fully dissolving, stirring for 4 hours under the ultrasonic state of 70kHz to uniformly disperse the silicon powder, adding 1 part of graphene and 1 part of carbon nanotubes as conductive agents, then adding 2 parts of glyoxal as a crosslinking agent, continuing stirring for a period of time until the stirring is stopped after the stirring is stopped, and standing for a period of time to form stable crosslinked chitosan coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 48 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent through freeze drying to obtain the crosslinked chitosan coated nano-silicon precursor.
And pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor for 6h at 220 ℃ in the air, heating to 700 ℃ at the heating rate of 5 ℃/min in the inert atmosphere, preserving the temperature for 3.5h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon negative electrode material.
Example 5.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 10 parts of acetic acid to form an acetic acid solution, adding 10 parts of chitosan with the molecular weight of 50 ten thousand and the deacetylation degree of 75%, stirring for dissolving, adding 2 parts of 60-80 nm silicon powder after fully dissolving, stirring for 3 hours under the ultrasonic state of 60kHz to uniformly disperse the silicon powder, adding 0.5 part of water-soluble asphalt as a conductive agent, adding 5 parts of glutaraldehyde as a crosslinking agent, continuing stirring for a period of time until the stirring is stopped after the stirring is stopped, and standing for a period of time to form stable crosslinked chitosan-coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 36 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent to obtain the crosslinked chitosan coated nano-silicon precursor.
Pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor for 8h at 200 ℃ in the air, then heating to 600 ℃ at the heating rate of 5 ℃/min in the inert atmosphere, preserving the heat for 4h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon cathode material.
Example 6.
The preparation method of the crosslinked chitosan derived silicon-carbon negative electrode material provided by the embodiment is as follows:
taking a certain amount of deionized water, recording the mass of the deionized water as 500 parts, adding 5 parts of acetic acid to form an acetic acid solution, adding 5 parts of chitosan with the molecular weight of 60 ten thousand and the deacetylation degree of 70%, stirring for dissolving, adding 1 part of silicon powder with the particle size of 80-100 nm after fully dissolving, stirring for 4 hours under the ultrasonic condition of 40kHz to uniformly disperse the silicon powder, adding 0.2 part of carbon nanotubes as a conductive agent, adding 4 parts of glyoxal as a crosslinking agent, continuing stirring for a period of time until the stirring is stopped after the stirring is stopped, and standing for a period of time to form stable crosslinked chitosan-coated nano silicon powder gel; and (3) freezing the sample in a low-temperature freezer for 24 hours, then putting the sample in a vacuum freeze dryer, freeze-drying the sample for 24 hours at the temperature of 50 ℃ below zero and under the pressure of 1-10 Pa, and removing the solvent to obtain the crosslinked chitosan coated nano-silicon precursor.
Pre-oxidizing the prepared cross-linked chitosan coated nano-silicon precursor for 1h at 300 ℃ in the air, then heating to 1200 ℃ at the heating rate of 5 ℃/min in the inert atmosphere, preserving the temperature for 0.5h, and naturally cooling to room temperature to obtain the cross-linked chitosan derived silicon-carbon composite material.
Example 7.
The crosslinked chitosan-derived silicon-carbon composite material prepared in the embodiments 1-6 of the invention is subjected to electrochemical performance test. The prepared silicon-carbon composite material is made into an electrode plate, a lithium plate is used as a counter electrode to assemble a CR2016 type lithium ion button cell, and the CR2016 type lithium ion button cell is subjected to a 0.1A charge-discharge cycle test, wherein the test results are shown in attached figures 3 and 4, the first coulombic efficiency of the material prepared in the example 1 is 69.1%, and the first specific discharge capacity is 1606mAh g-1Second discharge specific capacity 1323mAh g-1Gradually increases to 1395mAh g-1Then slowly decreases, and the capacity still has 1234mAh g after 100 cycles-1. Under the condition of not adding a conductive agent, the prepared silicon-carbon composite material has better electrochemical performance.
The embodiment 2-6 is a silicon-carbon composite material prepared by adding different conductive agents, and the electrochemical properties of the silicon-carbon composite material can show that the addition of the conductive agent further improves the conductivity of the material, reduces the internal resistance, and improves the first coulombic efficiency and the cycling stability. The initial coulombic efficiencies of the embodiments 2 to 6 are 73.1%, 74.1%, 75.4%, 72.2% and 76.2% respectively, the number of cycles when the specific discharge capacity reaches the peak value is obviously higher than that of the material prepared in the embodiment 1, the material capacity utilization rate is higher, the attenuation rate is reduced when the cycle is 100 cycles, and the prepared silicon-carbon composite material has more excellent electrochemical performance.
In summary, the silicon-carbon composite materials prepared in examples 1 to 6 all have good electrochemical properties.
The raw materials listed in the invention, the values of the upper limit and the lower limit and the interval of the raw materials, and the values of the upper limit and the lower limit and the interval of the process parameters can all realize the invention, and the examples are not listed.
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (10)

1. A preparation method of a cross-linked chitosan derived silicon-carbon negative electrode material is characterized by comprising the following steps:
adding acetic acid into deionized water to form an acetic acid solution, adding chitosan, stirring, adding nano silicon powder after full dissolution, stirring under an ultrasonic state to uniformly disperse the nano silicon powder, adding or adding a proper amount of nano carbon material as a conductive agent, then dropwise adding a crosslinking agent to form silicon-containing chitosan gel, and removing the solvent to obtain a crosslinked chitosan-coated nano silicon precursor;
the crosslinked chitosan-coated nano silicon precursor is subjected to pre-oxidation in air and high-temperature heat treatment in an inert atmosphere to obtain the crosslinked chitosan-derived silicon-carbon negative electrode material.
2. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the molecular weight of the chitosan is 1-60 ten thousand, and the deacetylation degree is more than or equal to 70%; the particle size of the nano silicon powder is 10-100 nm.
3. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the conductive agent is one or more of water-soluble asphalt, graphene, carbon nanotubes and conductive carbon black.
4. The method for preparing the cross-linked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the cross-linking agent is one of glutaraldehyde and glyoxal.
5. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the solvent removal is freeze-dried, and the sample is frozen in a low-temperature freezer for 24 hours, and then put in a vacuum freeze-drying machine, and freeze-dried for 24-48 hours at a temperature of-50 ℃ and a pressure of 1-10 Pa.
6. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the mass ratio of the water, the acetic acid, the chitosan, the nano silicon powder, the conductive agent and the crosslinking agent is 500: 5-10: 1-10: 0-2: 1-5.
7. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the pre-oxidation treatment is carried out at a temperature ranging from 200 ℃ to 300 ℃ for a heat preservation time ranging from 1h to 8 h.
8. The preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in claim 1, wherein the inert atmosphere high-temperature heat treatment temperature is 600-1200 ℃, and the heat preservation time is 1-4 h.
9. A crosslinked chitosan-derived silicon-carbon negative electrode material prepared by using the preparation method of the crosslinked chitosan-derived silicon-carbon negative electrode material as claimed in any one of claims 1 to 8.
10. The use of the crosslinked chitosan-derived silicon carbon anode material of claim 9 in a lithium ion battery anode material.
CN202110171259.2A 2021-02-08 2021-02-08 Cross-linked chitosan derived silicon-carbon negative electrode material and preparation method thereof Pending CN112993224A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114361426A (en) * 2022-01-25 2022-04-15 山西大学 Preparation method and application of biomass-based silicon-carbon composite material

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112125304A (en) * 2020-09-25 2020-12-25 福建师范大学 Metal oxide modified micro-nano silicon-graphite composite negative electrode material and preparation method thereof

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112125304A (en) * 2020-09-25 2020-12-25 福建师范大学 Metal oxide modified micro-nano silicon-graphite composite negative electrode material and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
LUBING YU等: ""N-doped rGO/C@Si composites using sustainable chitosan as the carbon source for lithium-ion batteries"", 《APPLIED SURFACE SCIENCE》 *
WEIGUO CHEN: ""Silicon Anode Materials for Lithium Ion Batteries By High Energy Ball Milling"", 《UCLA ELECTRONIC THESES AND DISSERTATIONS》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114361426A (en) * 2022-01-25 2022-04-15 山西大学 Preparation method and application of biomass-based silicon-carbon composite material

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