CN113948688B - Modified pre-lithiated silica composite material and preparation method and application thereof - Google Patents
Modified pre-lithiated silica composite material and preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a modified pre-lithiated silica composite material, a preparation method thereof and application thereof in a lithium ion battery, wherein the modified pre-lithiated silica composite material has a core-shell structure and comprises an inner core of the pre-lithiated silica composite material, a silicon cladding intermediate layer and a carbon layer from inside to outside; the pre-lithiated silica composite material comprises nano silicon and lithium silicate; the lithium silicate comprises Li 2 SiO 3 A main phase; the content of the silicon coating intermediate layer is 2-93% of the total mass of the inner core of the pre-lithiated silica composite material and the silicon coating intermediate layer; the pH value of the modified pre-lithiated silica composite material is 6-10. The modified pre-lithiated silica composite material solves the problem of poor battery cycle performance caused by inapplicability of the traditional high-alkaline pre-lithiated silica material and a binder, and simultaneously greatly improves the first coulombic efficiency and the battery capacity.
Description
Technical Field
The invention relates to the technical field of lithium ion battery cathode materials, in particular to a modified pre-lithiated silica composite material, a preparation method and application thereof.
Background
In recent years, with the continuous development of new energy technology, lithium ion batteries are widely applied, however, the theoretical capacity of the traditional graphite negative electrode material is lower, and the requirement of the market on high energy density of the lithium ion batteries cannot be met. The research shows that the simple substance silicon has higher theoretical capacity, however, when the silicon is used as a negative electrode material in practice, the volume expansion rate of the silicon reaches 300%, slurry particles are easy to break and fall off, and the battery has lower initial coulomb efficiency and poorer cycling stability. The silicon oxide material is widely focused as a high specific capacity anode material, but the problems of low initial efficiency, poor circularity and the like caused by the silicon oxide material limit the wide application of the material. Therefore, improving the first coulombic efficiency and cycle performance of the silicon-oxygen anode material is a problem to be solved.
Based on the problem, many material research and development personnel continuously try to put forward the thought of pre-supplementing lithium, namely doping part of metal lithium while synthesizing the anode material so as to compensate irreversible lithium element consumed in battery reaction and improve the first coulombic efficiency of the battery. The first coulomb efficiency of the silicon-oxygen material can be obviously improved by a pre-lithiation mode, but the pre-lithiated silicon-oxygen material often has problems in the process of preparing the battery pole piece, such as the rise of pH value during the preparation of aqueous slurry, easy gas generation, easy generation of particles, pores and the like during the coating of the slurry, and poor electronic conductivity, low first coulomb efficiency and low cycle performance of the lithium-containing silicon-oxygen material. The main reason of the problem is that the traditional pre-lithiated silica composite material has stronger alkalinity and the pH value reaches over 11 and even over 12 through analysis. The cathode material with strong alkalinity can react with the binder used in the preparation of the battery to destroy the structure of the binder, so that the cycle performance of the battery using the material is fast attenuated, the overall performance of the battery is poor, and the commercial application of the pre-lithiated silica material is seriously affected.
Disclosure of Invention
Aiming at the problems in the prior art, the invention discloses a modified pre-lithiated silica composite material, wherein the pH value of the modified pre-lithiated silica composite material is 6-10, so that the problem that the battery cycle performance is poor due to inapplicability of the traditional high-alkalinity pre-lithiated silica material and a binder is solved, and the battery capacity is greatly improved.
The specific technical scheme is as follows:
the modified pre-lithiated silica composite material has a core-shell structure, and comprises an inner core of the pre-lithiated silica composite material, a silicon-coated intermediate layer and a carbon layer from inside to outside;
the pre-lithiated silica composite material comprises nano silicon and lithium silicate;
the lithium silicate comprises Li 2 SiO 3 A main phase;
the content of the silicon coating intermediate layer is 2-93% of the total mass of the inner core of the pre-lithiated silicon oxide composite material and the silicon coating intermediate layer;
the pH value of the modified pre-lithiated silica composite material is 6-10.
The invention discloses a modified pre-lithiated silica composite material, which is characterized in that the surface of the pre-lithiated silica composite material is coated with a certain content of complete silicon layer, so that the pH value of the modified pre-lithiated silica composite material is controlled below 10, and the main phase of lithium silicate in the modified pre-lithiated silica composite material is ensured to be Li 2 SiO 3 The modified pre-lithiated silica composite material is used as a negative electrode material in the field of lithium ion batteries, and can remarkably improve the first coulombic efficiency, capacity and cycling stability of the batteries.
Preferably:
the diameter of the inner core is 0.1-300 mu m, the thickness of the silicon coating intermediate layer is 0.1-200 mu m, and the thickness of the carbon layer is 0.1-100 mu m.
Preferably:
the lithium silicate further comprises Li 2 Si 2 O 5 The presence of this phase may enhance the first coulombic efficiency of the battery.
The nano silicon is uniformly distributed in the lithium silicate.
Preferably:
in the modified pre-lithiated silica composite material, the content of the carbon layer is 2-20%.
Further preferred is:
the content of the silicon coating intermediate layer is 6-8% of the total mass of the inner core of the pre-lithiated silicon oxide composite material and the silicon coating intermediate layer; more preferably 6.2 to 7.3%.
The pH value of the modified pre-lithiated silica composite material is 6.5-7.5.
Experiments show that the modified pre-lithiated silica composite material has the preferable silicon content and the preferable pH value, and the finally assembled lithium ion battery has excellent first reversible capacity and high cycle stability, the first coulombic efficiency is not lower than 90%, the 50-cycle capacity retention rate is not lower than 85%, and the highest first reversible capacity can reach 1800mAh/g.
The invention also discloses a preparation method of the modified pre-lithiated silica composite material, which comprises the following steps:
s1, disproportionating SiO x Mixing with lithium compound in protective atmosphere, and roasting in protective gas atmosphere or vacuum condition to obtain pre-lithiated silica composite material;
said disproportionation of SiO x In (0)<x<1.5；
S2, placing the pre-lithiated silica composite material prepared in the step S1 in a mixed atmosphere containing a silicon source, and roasting at high temperature to obtain the pre-lithiated silica composite material with a surface coated with a silicon layer;
and S3, blending the pre-lithiated silica composite material with the surface coated with the silicon layer prepared in the step S2 with an organic carbon source, and carrying out carbon coating treatment by high-temperature calcination to obtain the modified pre-lithiated silica composite material.
The invention discloses a preparation process, which comprises the following steps of disproportionating SiO in step S1 x As a raw material, experiments show that compared with the common SiO adopted x As raw material by disproportionating SiO x Is more beneficial to the pre-lithiation of the raw materials.
Said disproportionation of SiO x The preparation of (3) is specifically as follows:
taking silicon powder and silicon dioxide powder as raw materials, mixing uniformly, putting into a vacuum furnace, vacuumizing, heating to 900-1500 ℃ and preserving heat for 2-25 h to generate SiO x Cooling and shaping the steam to obtain SiO x Putting the powder into a vacuum furnace, heating to 700-1100 ℃ under argon atmosphere, and preserving heat for 2-20 h to obtain disproportionated SiO x 。
The mass ratio of the silicon powder to the silicon dioxide powder is 1:1 to 3.
The disproportionation reaction temperature (700-1100 ℃) is too high or too long, which can lead to the rapid growth of silicon grains and the degradation of the cycle performance of the material; if the disproportionation temperature is too low, the disproportionation reaction cannot be performed, which is disadvantageous for the post-prelithiation reaction.
The shaping comprises one or more of crushing, ball milling and sieving.
Preferably, in step S1:
the lithium-containing compound is selected from one or more of lithium hydride, lithium borohydride, metal lithium, aluminum lithium hydride, lithium-containing alloy, lithium amide and alkyl lithium;
said disproportionation of SiO x The mass ratio of the lithium-containing compound to the lithium-containing compound is 1:0.02 to 0.7;
the mixing of the raw materials can be performed by mixing, fusing, ball milling or stirring by a mixer.
The protective atmosphere is selected from one or more of hydrogen, nitrogen, helium, neon and argon;
the roasting is carried out at the temperature of 300-1000 ℃ for 2-15 h.
The too high roasting temperature or too long roasting time can lead to the rapid growth of silicon grains, so that the electrochemical performance of the material is reduced; if the roasting temperature is too low, the pre-lithiation reaction is incomplete, the material composition is uneven, and the expected pre-lithiation effect cannot be achieved.
Preferably, in step S2:
the mixed atmosphere of the silicon-containing source comprises a silicon source and a protective atmosphere;
the silicon source is selected from one or more of silane, trichlorosilane, silicon tetrafluoride, silicon tetrachloride and dichlorosilane, and the protective atmosphere is selected from one or more of hydrogen, nitrogen, helium, neon and argon;
in the mixed atmosphere, the volume content of the silicon source is 2-99%.
The high-temperature roasting is carried out at 400-900 ℃ for 0.1-20 h;
the active substances in the inner core react when the temperature is too high, the structure is changed, and the material performance is affected; when the temperature is too low, the silicon-containing gas source cannot be decomposed, and a silicon cladding structure layer cannot be formed; too short a coating time leads to difficult formation or uneven coating of the silicon coating layer, too long a coating time leads to too thick silicon coating layer, easy agglomeration into large particles, and easy expansion and easy fragmentation of the particle volume. Further preferably, the high-temperature roasting is performed at a temperature of 450-650 ℃ for 1-5 hours.
The mass ratio of the pre-lithiated silica composite material to the silicon source is 1:0.03 to 1.
The mass ratio of the two is too large, which can lead to the non-compact silicon coating layer, the pH value of the material is higher, and the electrochemical performance of the material is reduced; too low mass ratio can result in too high silicon content, large volume expansion rate of the material, easy breakage of particles and reduced electrochemical performance. Further preferably, the mass ratio of the pre-lithiated silica composite material to the silicon source is 1:0.1 to 0.2; more preferably 1:0.1 to 0.17. Preferably, in step S3:
the organic carbon source is selected from an organic carbon source and/or a solid organic carbon source;
the organic carbon source is selected from one or more of methane, ethylene, acetylene, acetone or benzene, and the solid organic carbon source is selected from one or more of hydrocarbons, oil esters, saccharides, organic acids or asphalt;
the high-temperature calcination temperature is 600-1000 ℃ and the time is 0.5-10 h.
The invention also discloses application of the modified pre-lithiated silica composite material in preparation of lithium ion batteries. The lithium ion battery assembled by taking the lithium ion battery as the negative electrode material has excellent first coulomb efficiency, first reversible capacity and high cycle stability.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a modified pre-lithiated silica composite material, which has a multi-layer core-shell structure, and the pH value of the pre-lithiated silica composite material is effectively reduced by adopting a silicon coating mode, so that the problem of poor cycle performance caused by mismatching of an alkaline material and a binder in a traditional pre-lithiated product is solved; the lithium ion battery assembled by the modified pre-lithiated silica composite material with the specific structure has excellent first coulombic efficiency, first reversible capacity and high cycle stability.
The invention discloses a preparation method of a modified pre-lithiated silica composite material, which uses disproportionated SiO x As a raw material, the lithium element consumed by the generation of irreversible lithium silicate in the battery reaction is compensated by higher pre-lithiation reaction degreeThe first coulombic efficiency of the battery is improved, and simultaneously SEI film formed on the contact surface of the cathode material and the electrolyte is avoided. Simple preparation process, low cost, high operability, high safety and the like.
Drawings
FIG. 1 is a schematic structural diagram of a modified prelithiated silica composite prepared by the invention, wherein the silica composite comprises a 1-core, a 2-silicon cladding intermediate layer and a 3-carbon layer;
FIG. 2 is an XRD pattern of the modified pre-lithiated silicone composite material prepared in example 1;
FIG. 3 is an SEM image of a modified pre-lithiated silicone composite material prepared in example 2;
fig. 4 is an XRD pattern of the silica composite prepared in comparative example 3.
Detailed Description
The present invention will be described in further detail with reference to examples and comparative examples, but embodiments of the present invention are not limited thereto.
Example 1
1) 1kg of Si powder and 1.7kg of SiO were taken out respectively 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 5Pa, heating to 1300 ℃ and preserving heat for 20h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 900 ℃ under argon atmosphere, and preserving heat for 5 hours to obtain disproportionated SiO x Powder material.
2) Taking SiO after disproportionation x 3kg of powder material is put into a mixing tank, 500g of metallic lithium is added, mixed for 30min under nitrogen atmosphere, taken out, put into a vacuum furnace, roasted for 5h under argon atmosphere, roasting temperature is 750 ℃, natural cooling is carried out to room temperature, and the material is taken out, thus obtaining the pre-lithiated composite material.
3) 2kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) Mixed atmosphere (volume ratio of silane to argon is 1:5) composed of argon as shielding gas, and mass ratio of pre-lithiated composite material to silaneIs 1: and 0.15, depositing for 1h at the roasting temperature of 550 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coated pre-lithiated composite material, wherein the content of the coated silicon is 6.5%.
4) Taking 1.5kg of the silicon-containing coated pre-lithiated composite material obtained in the above steps, placing in a CVD rotary furnace, introducing ethylene as a carbon source, introducing nitrogen as a protective gas, depositing at 900 ℃ for 1.5h, cooling, and taking out to obtain the modified pre-lithiated silicon-oxygen composite material.
The shape and the composition characterization show that the diameter of the inner core of the modified pre-lithiated silica composite material prepared by the implementation is 7.4 mu m, the thickness of the silicon coating intermediate layer is 5.3 mu m, and the thickness of the carbon layer is 4 mu m; the carbon layer content in the composite material was 4.1%.
Performance test:
the cathode material comprises the following components: conductive agent sp: dispersant cmc: binder aone=70: 15:5:10, mixing materials, stirring uniformly, coating, putting into a baking oven for baking, taking a pole piece for rolling, punching the pole piece, weighing the pole piece, putting into a vacuum baking oven for baking, and taking the pole piece into a glove box for making buckling. And sequentially placing a negative electrode material, a diaphragm, electrolyte and a lithium positive electrode sheet to assemble the battery. The battery was discharged from 0.01V to 0.005V at 0.05C rate and charged at 0.1C rate.
Example 2
1) 1.5kg of Si powder and 3kg of SiO were taken respectively 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 5Pa, heating to 1350 ℃ and preserving heat for 25h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 950 ℃ under argon atmosphere, and preserving heat for 5 hours to obtain disproportionated SiO x Powder material.
2) Taking SiO after disproportionation x 2kg of powder material is put into a mixing tank, 200g of lithium hydride is added, mixed for 30min under the argon atmosphere, taken out, put into a vacuum furnace, roasted for 5h under the argon atmosphere, the roasting temperature is 850 ℃, and the material is naturally cooled to room temperature, and taken out, thus obtaining the pre-lithiated composite material.
3) 2kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And a mixed atmosphere (the volume ratio of silane is 80%) composed of argon as a protective gas, wherein the mass ratio of the pre-lithiated composite material to the silane is 1: and 0.1, depositing for 1.5 hours at the roasting temperature of 600 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coated pre-lithiated composite material. Wherein the silicon content of the coating is 6.2%.
4) Taking 1.5kg of the silicon-containing coated pre-lithiated composite material obtained in the above steps, placing in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a protective gas, depositing for 1.5h at 950 ℃, cooling, and taking out to obtain the modified pre-lithiated silicon-oxygen composite material.
Fig. 3 is an SEM image of the modified prelithiated silica composite material prepared in the embodiment, and the observation of the image shows that the material has smoother surface, uniform particle size distribution, no obvious difference in particle morphology and better uniformity.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Example 3
1) Respectively taking 3kg of Si powder and 5kg of SiO 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 5Pa, heating to 1350 ℃ and preserving heat for 24h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 850 ℃ under the argon atmosphere, and preserving heat for 8 hours to obtain SiO after disproportionation x Powder material.
2) Taking SiO after disproportionation x 3kg of powder material is put into a mixing tank, 250g of lithium borohydride is added, mixed for 30min under argon atmosphere, taken out, put into a vacuum furnace, roasted for 7h under argon atmosphere, roasting temperature is 650 ℃, natural cooling is carried out to room temperature, and the material is taken out, thus obtaining the pre-lithiated composite material.
3) 3kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And argon group as shielding gasThe mass ratio of the pre-lithiated composite material to the silane is 1: and 0.17, depositing for 2 hours at the roasting temperature of 450 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coated pre-lithiated composite material. Wherein the silicon content of the coating is 7.3%.
4) Taking 1kg of the silicon-containing coated pre-lithiated composite material obtained in the above steps, placing in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a shielding gas, depositing for 2 hours at 850 ℃, cooling, and taking out to obtain the modified pre-lithiated silica composite material.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Example 4
1) 4kg of Si powder and 4.5kg of SiO are respectively taken 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 8Pa, heating to 1350 ℃ and preserving heat for 24h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 900 ℃ under argon atmosphere, and preserving heat for 10 hours to obtain disproportionated SiO x Powder material.
2) Taking SiO after disproportionation x 3kg of powder material is put into a mixing tank, 250g of lithium borohydride is added, mixed for 30min under argon atmosphere, taken out, put into a vacuum furnace, roasted for 7h under argon atmosphere, roasting temperature is 650 ℃, natural cooling is carried out to room temperature, and the material is taken out, thus obtaining the pre-lithiated composite material.
3) 2.4kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And a mixed atmosphere (the volume ratio of silane is 70%) composed of argon as a protective gas, wherein the mass ratio of the pre-lithiated composite material to the silane is 1: and (3) depositing for 1.5 hours at the roasting temperature of 550 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coating layer prelithiation composite material. Wherein the silicon content of the coating is 6.8%.
4) Taking 1kg of the silicon-containing coating layer prelithiation composite material obtained in the above steps, placing in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a shielding gas, depositing for 2 hours at 850 ℃, cooling, and taking out to obtain the modified prelithiation silicon-oxygen composite material.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Example 5
1) 2.3kg of Si powder and 2.6kg of SiO are taken respectively 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 8Pa, heating to 1350 ℃ and preserving heat for 24h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 950 ℃ under the argon atmosphere, and preserving the heat for 10 hours to obtain the disproportionated SiO x Powder material.
2) Taking SiO after disproportionation x 2kg of powder material is put into a mixing tank, 180g of lithium hydride is added, mixed for 30min under the argon atmosphere, taken out, put into a vacuum furnace, roasted for 7h under the argon atmosphere, roasting temperature is 750 ℃, natural cooling is carried out to room temperature, and the material is taken out, thus obtaining the pre-lithiated composite material.
3) 1.8kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And a mixed atmosphere (the volume ratio of silane is 75%) composed of argon as a protective gas, wherein the mass ratio of the pre-lithiated composite material to the silane is 1: and (3) depositing for 1.5 hours at the roasting temperature of 500 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coating layer prelithiation composite material. Wherein the silicon content of the coating is 2.1%.
4) Taking 1.6kg of the silicon-containing coating layer prelithiation composite material obtained in the steps, placing the composite material in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a shielding gas, depositing for 2 hours at 800 ℃, cooling, and taking out the composite material to obtain the modified prelithiation silicon-oxygen composite material.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Example 6
1) 2.4kg of Si powder and 2.6kg of SiO are taken respectively 2 The purity of the powder is 99Adding more than 9% of the materials into a mixer, mixing for 1h, putting the mixed materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 8Pa, heating to 1350 ℃ and preserving heat for 24h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Putting the powder material into a vacuum furnace, heating to 980 ℃ under the argon atmosphere, and preserving the heat for 10 hours to obtain the disproportionated SiO x Powder material.
2) Taking SiO after disproportionation x 2kg of powder material is put into a mixing tank, 210g of lithium borohydride is added, mixed for 30min under argon atmosphere, taken out, put into a vacuum furnace, roasted for 7h under argon atmosphere, roasting temperature is 800 ℃, natural cooling is carried out to room temperature, and the material is taken out, thus obtaining the pre-lithiated composite material.
3) 1.6kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And a mixed atmosphere (the volume ratio of silane is 65%) composed of argon as a protective gas, wherein the mass ratio of the pre-lithiated composite material to the silane is 1:1, depositing for 2 hours at the roasting temperature of 650 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coating layer prelithiation composite material. Wherein the silicon content of the coating is 93%.
4) Taking 1.3kg of the silicon-containing coating layer prelithiation composite material obtained in the steps, placing the composite material in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a shielding gas, depositing for 2 hours at 850 ℃, cooling, and taking out the composite material to obtain the modified prelithiation silicon-oxygen composite material.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Example 7
1) Respectively taking 3.2kg of Si powder and 3.5kg of SiO 2 Adding the powder with the purity of over 99.9 percent into a mixer, mixing for 1h, putting the mixed raw materials into a vacuum furnace, vacuumizing until the air pressure in the furnace is 5Pa, heating to 1300 ℃ and preserving the heat for 24h; siO to be generated x The steam is quickly condensed to generate SiO x Taking out the solid blocks, crushing, ball milling and sieving to obtain SiO x A powder material; siO is made of x Powder material is put into a vacuum furnace and added under argon atmosphereHeating to 940 ℃ and preserving heat for 10 hours to obtain SiO after disproportionation x Powder material.
2) Taking SiO after disproportionation x 3kg of powder material is put into a mixing tank, 320g of lithium borohydride is added, mixed for 30min under argon atmosphere, taken out, put into a vacuum furnace, roasted for 7h under argon atmosphere, the roasting temperature is 850 ℃, and the material is naturally cooled to room temperature, and taken out, thus obtaining the pre-lithiated composite material.
3) 1.6kg of the pre-lithiated composite material was placed in a rotary kiln and charged with Silane (SiH) 4 ) And a mixed atmosphere (the volume ratio of silane is 68%) composed of argon as a protective gas, wherein the mass ratio of the pre-lithiated composite material to the silane is 1: and 0.52, depositing for 2 hours at the roasting temperature of 650 ℃, naturally cooling to room temperature, and taking out the material to obtain the silicon-containing coating layer prelithiation composite material. Wherein the silicon content of the coating is 46%.
4) Taking 1.4kg of the silicon-containing coating layer prelithiation composite material obtained in the steps, placing the composite material in a CVD rotary furnace, introducing methane as a carbon source, introducing nitrogen as a protective gas, depositing at 800 ℃ for 1.5h, cooling, and taking out the composite material to obtain the modified prelithiation silicon-oxygen composite material.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Comparative example 1
The preparation process is essentially the same as in example 1, except that the step of coating the silicon layer of step 3) is not performed, but the pre-lithiated composite material is directly subjected to carbon coating.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Comparative example 2
The preparation process is essentially the same as in example 2, except that in step 3), the calcination temperature and time are replaced by 350℃and 2 hours, respectively.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Comparative example 3
The preparation process is essentially the same as in example 2, except that in step 3), the calcination temperature is replaced by 1000 ℃.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
Comparative example 4
The preparation process was essentially the same as in example 3, except that in step 3), the calcination time was replaced by 5min.
Comparative example 5
The preparation process is essentially the same as in example 3, except that in step 3), the mass ratio of prelithiated composite material to silane is replaced by 1:0.005, wherein the content of the coated silicon in the prepared silicon-containing coated pre-lithiated composite material is 0.0034%.
The assembly and electrochemical performance test of the cell were exactly the same as in example 1.
The performance test results of the lithium ion batteries respectively assembled with the above examples and comparative examples are shown in table 1 below.
TABLE 1
The applicant states that the present invention is illustrated by the above examples as a detailed method of the present invention, but the present invention is not limited to the above detailed method.
Claims (8)
1. The preparation method of the modified pre-lithiated silica composite material is characterized by comprising the following steps:
s1, disproportionating SiO x Mixing with lithium compound in protective atmosphere, and roasting in protective gas atmosphere or vacuum condition to obtain pre-lithiated silica composite material;
said disproportionation of SiO x In (0)<x<1.5；
S2, placing the pre-lithiated silica composite material prepared in the step S1 in a mixed atmosphere containing a silicon source, and roasting at high temperature to obtain the pre-lithiated silica composite material with a surface coated with a silicon layer;
the mass ratio of the pre-lithiated silica composite material to the silicon source is 1:0.1 to 0.17;
the high-temperature roasting is carried out at the temperature of 400-900 ℃ for 0.1-20 hours;
s3, blending the pre-lithiated silica composite material with the surface coated with the silicon layer prepared in the step S2 with an organic carbon source, and performing carbon coating treatment through high-temperature calcination to obtain the modified pre-lithiated silica composite material;
the modified pre-lithiated silica composite material has a core-shell structure, and comprises an inner core of the pre-lithiated silica composite material, a silicon cladding intermediate layer and a carbon layer from inside to outside;
the pre-lithiated silica composite material comprises nano silicon and lithium silicate;
the lithium silicate comprises Li 2 SiO 3 A main phase;
the content of the silicon coating intermediate layer is 6-8% of the total mass of the inner core of the pre-lithiated silicon oxide composite material and the silicon coating intermediate layer;
the pH value of the modified pre-lithiated silica composite material is 6.5-7.5.
2. The method for preparing a modified pre-lithiated silicone composite material of claim 1, wherein in step S1:
the lithium-containing compound is selected from one or more of lithium hydride, lithium borohydride, lithium aluminum hydride, lithium amide and lithium alkyl;
said disproportionation of SiO x The mass ratio of the lithium-containing compound to the lithium-containing compound is 1: 0.02-0.7;
the protective atmosphere is selected from one or more of hydrogen, nitrogen, helium, neon and argon;
and the roasting is carried out at the temperature of 300-1000 ℃ for 2-15 h.
3. The method for preparing a modified pre-lithiated silicone composite material of claim 1, wherein in step S2:
the mixed atmosphere of the silicon-containing source comprises a silicon source and a protective atmosphere;
the silicon source is selected from one or more of silane, trichlorosilane, silicon tetrafluoride, silicon tetrachloride and dichlorosilane, and the protective atmosphere is selected from one or more of hydrogen, nitrogen, helium, neon and argon.
4. The method for preparing a modified pre-lithiated silicone composite material of claim 1, wherein in step S3:
the organic carbon source is selected from an organic carbon source and/or a solid organic carbon source;
the organic carbon source is selected from one or more of methane, ethylene or acetylene, and the solid organic carbon source is selected from one or more of hydrocarbons, oil esters, saccharides, organic acids or asphalt;
the high-temperature calcination temperature is 600-1000 ℃ and the time is 0.5-10 h.
5. The method for preparing a modified pre-lithiated silicone composite material according to any one of claims 1 to 4, wherein in step S2:
and the high-temperature roasting is carried out at the temperature of 450-650 ℃ for 1-5 h.
6. The method for preparing a modified pre-lithiated silicone composite material of claim 1, wherein the diameter of the inner core is 0.1-300 μm;
the lithium silicate further comprises Li 2 Si 2 O 5 ；
The nano silicon is uniformly distributed in the lithium silicate;
the thickness of the silicon coating intermediate layer is 0.1-200 mu m.
7. The method for preparing a modified pre-lithiated silica composite material of claim 1, wherein the carbon layer has a thickness of 0.1 to 100 μm;
in the modified pre-lithiated silica composite material, the content of the carbon layer is 2-20%.
8. Use of a modified pre-lithiated silica composite material prepared according to the method of any one of claims 1-7 in the preparation of a lithium ion battery.
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| CN114744166A (en) * | 2022-02-25 | 2022-07-12 | 深圳市翔丰华科技股份有限公司 | Preparation method of pre-lithiated silica composite material |
| CN114613961B (en) * | 2022-03-15 | 2024-07-30 | 宁波杉杉新材料科技有限公司 | Modified pre-lithiated silica material, preparation method and application thereof, negative electrode plate and lithium ion battery |
| CN114709389B (en) * | 2022-03-30 | 2023-04-18 | 浙江锂宸新材料科技有限公司 | Pre-lithiation negative electrode material and preparation method and application thereof |
| CN115148994A (en) * | 2022-06-29 | 2022-10-04 | 宁波杉杉新材料科技有限公司 | Pre-lithiated silica composite material, preparation method thereof, negative pole piece, battery and application |
| CN115986094B (en) * | 2023-03-01 | 2024-06-25 | 江苏正力新能电池技术有限公司 | Pre-lithiated silicon oxide anode material with core-shell structure, and preparation method and application thereof |
| CN116936775A (en) * | 2023-09-15 | 2023-10-24 | 宁德时代新能源科技股份有限公司 | Negative electrode material, preparation method thereof, negative electrode plate, battery and power utilization device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108493438A (en) * | 2018-04-27 | 2018-09-04 | 天津巴莫科技股份有限公司 | A kind of lithium ion battery SiOxBase composite negative pole material and preparation method thereof |
| CN112751029A (en) * | 2019-10-30 | 2021-05-04 | 贝特瑞新材料集团股份有限公司 | Silica composite negative electrode material, preparation method thereof and lithium ion battery |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6507106B2 (en) * | 2016-01-07 | 2019-04-24 | 信越化学工業株式会社 | Negative electrode active material, mixed negative electrode active material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, method of producing negative electrode active material, and method of producing lithium ion secondary battery |
| CN108172791B (en) * | 2017-12-25 | 2020-10-16 | 贝特瑞新材料集团股份有限公司 | Composite negative electrode material, preparation method thereof and lithium ion battery |
| US11152613B2 (en) * | 2018-01-19 | 2021-10-19 | Amprius, Inc. | Stabilized, prelithiated silicon oxide particles for lithium ion battery anodes |
| CN109449416B (en) * | 2018-11-01 | 2022-03-08 | 中化国际(控股)股份有限公司 | Silica material and preparation method thereof |
| CN112803015A (en) * | 2019-11-14 | 2021-05-14 | 贝特瑞新材料集团股份有限公司 | Negative electrode material, preparation method thereof and lithium ion battery |
| CN110993949B (en) * | 2019-12-17 | 2022-07-22 | 江苏正力新能电池技术有限公司 | Cathode material with multiple coating structures, preparation method and application thereof |
| CN111106351B (en) * | 2019-12-30 | 2022-05-13 | 无锡零一未来新材料技术研究院有限公司 | Negative electrode lithium supplement additive and preparation method thereof |
| CN111362269A (en) * | 2020-03-09 | 2020-07-03 | 上海电气集团股份有限公司 | Preparation method of SEI (solid electrolyte interphase) film of lithium ion battery cathode, lithium ion battery cathode material and application of lithium ion battery cathode material |
| CN111554910B (en) * | 2020-05-19 | 2022-04-12 | 溧阳天目先导电池材料科技有限公司 | Lithium battery negative electrode material containing pre-lithiated silylene material, preparation method thereof and lithium battery |
| CN111900369A (en) * | 2020-07-24 | 2020-11-06 | 陕西煤业化工技术研究院有限责任公司 | Pre-lithiated silicon oxide/carbon composite material and preparation method and application thereof |
| CN112467108B (en) * | 2020-11-26 | 2022-04-12 | 东莞理工学院 | Porous silica composite material and preparation method and application thereof |
| CN112687852B (en) * | 2020-12-10 | 2022-08-26 | 安普瑞斯（南京）有限公司 | Silica lithium particle, preparation method thereof, negative electrode material, pole piece and battery |
| CN113066972B (en) * | 2021-03-19 | 2022-06-17 | 厦门高容新能源科技有限公司 | Lithium-supplementing silicon material, preparation method thereof, electrode containing lithium-supplementing silicon material and battery |
| CN113130868A (en) * | 2021-04-09 | 2021-07-16 | 昆山宝创新能源科技有限公司 | Composite material containing silicon monoxide, negative plate, lithium battery and preparation method thereof |
| CN113193181B (en) * | 2021-04-23 | 2022-10-11 | 湖州杉杉新能源科技有限公司 | Pre-lithiated silica-oxygen composite material, precursor, preparation method and application thereof |
| CN113437280B (en) * | 2021-08-30 | 2021-11-30 | 北京壹金新能源科技有限公司 | Slurry-stabilized lithiated silicon-based composite material and preparation method and application thereof |
-
2021
- 2021-09-30 CN CN202111163940.9A patent/CN113948688B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108493438A (en) * | 2018-04-27 | 2018-09-04 | 天津巴莫科技股份有限公司 | A kind of lithium ion battery SiOxBase composite negative pole material and preparation method thereof |
| CN112751029A (en) * | 2019-10-30 | 2021-05-04 | 贝特瑞新材料集团股份有限公司 | Silica composite negative electrode material, preparation method thereof and lithium ion battery |
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