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KR-20260062988-A - Porous composite elastomer, silicon-carbon, and its manufacturing method and applications

KR20260062988AKR 20260062988 AKR20260062988 AKR 20260062988AKR-20260062988-A

Abstract

The present application relates to the field of battery anode material technology, and in particular to porous composite elastomers, silicon-carbon, and methods for manufacturing and applications thereof. The present application provides a porous composite elastomer having a porous structure, wherein the porous composite elastomer comprises a flexible body and a rigid body that interpenetrate each other, wherein the raw material of the flexible body comprises carbon nanotubes, and the rigid body comprises hard carbon. The present application manufactures a silicon-carbon composite material by composited silicon with carbon nanotubes and hard carbon as carbon sources, and compared to a general silicon-carbon composite material, the carbon nanotubes act as a bridge between silicon and hard carbon to effectively improve electrical conductivity and ion conduction energy, thereby improving the rate capability of the anode material.

Inventors

  • 두 닝
  • 추 샤오위
  • 웨 민

Assignees

  • 카본 원 뉴 에너지 그룹 컴퍼니 리미티드
  • 저지앙 리천 뉴 머터리얼 테크놀로지 컴퍼니 리미티드

Dates

Publication Date
20260507
Application Date
20250117
Priority Date
20240208

Claims (20)

  1. As a porous composite elastomer having a porous structure, The above porous composite elastomer comprises a flexible body and a rigid body that penetrate each other, wherein the material of the flexible body comprises carbon nanotubes, and the rigid body is hard carbon.
  2. In paragraph 1, The above porous composite elastomer contains uniformly distributed micropores and/or mesopores; and/or A porous composite elastomer characterized by a mass ratio of (0.01 to 2):1 between the flexible body and the rigid body.
  3. In paragraph 2, It includes one or more of the following features a1) to a7), a1) The average pore size of the above porous composite elastomer is <15 nm; a2) The total pore volume of the porous composite elastomer is 0.2 to 1.5 cm³ /g; a3) The specific surface area of the above porous composite elastomer is >200 m² /g; a4) The D 50 of the porous composite elastomer is <30μm; a5) The tap density of the porous composite elastomer is 0.1 to 1.0 g/ cm³ ; a6) The resistivity of the porous composite elastomer is <5Ω·cm, preferably <0.5Ω·cm; a7) A porous composite elastomer characterized in that the pore size concentration of the above porous composite elastomer is <7.
  4. In paragraph 3, It includes one or more of the following features a1) to a7), a1) The average pore size of the porous composite elastomer is 1.8 to 10 nm; a2) The total pore volume of the porous composite elastomer is 0.4 to 1.1 cm³ /g; a3) The specific surface area of the above porous composite elastomer is >700 m² /g; a4) The D 50 of the porous composite elastomer is <20μm; a5) The tap density of the porous composite elastomer is 0.2 to 0.7 g/ cm³ ; a6) The resistivity of the above porous composite elastomer is <0.05Ω·cm; a7) A porous composite elastomer characterized in that the pore size concentration of the above porous composite elastomer is 0.5 to 5.
  5. A method for manufacturing a porous composite elastomer according to any one of claims 1 to 4, The above manufacturing method is, Preparation of carbon tube aggregates: Step S1 of preparing carbon tube aggregates by molding carbon nanotubes; Manufacturing of a carbon tube composite elastomer: Step S2, in which carbon tube aggregates are added to a solution containing a soft template and a polymer so that the solution penetrates into the carbon tube aggregates, and then heat-cured to obtain a carbon tube composite elastomer; and Manufacturing of a porous composite elastomer: A manufacturing method comprising step S3 of obtaining a porous composite elastomer by high-temperature carbonization and activation treatment of a carbon tube composite elastomer.
  6. In paragraph 5, In step S1, the molding is performed using a molding machine; and/or, in step S1, the length of the carbon nanotube is 0.1 to 50 μm and the tube diameter is 2 to 20 nm; and/or, in step S1, the carbon tube aggregate is spherical or spherical; and/or, in step S1, the sphericity Sh10% of the carbon tube aggregate is ≥0.70; and/or, in step S1, the sphericity Sh50% of the carbon tube aggregate is ≥0.80; and/or, in step S1, the sphericity Sh90% of the carbon tube aggregate is ≥0.85; and/or, in step S1, the D 50 of the carbon tube aggregate is 1 to 100 μm; and/or, a manufacturing method characterized in that, in step S1, the carbon tube aggregate has a structure in the form of a ball of yarn.
  7. In paragraph 6, A manufacturing method characterized in that the frequency of the main device of the molding machine is 5 to 60 Hz, the frequency of the auxiliary device is 20 to 90 Hz, the frequency of the fan is 8 to 30 Hz, and the operating time is 2 to 100 min.
  8. In paragraph 5, A manufacturing method characterized by further including an intermediate modification treatment between step S1 and step S2: a step of adding carbon tube aggregates to an acidic solution, stirring, filtering to obtain a solid, washing until neutral, and drying to obtain modified carbon tube aggregates.
  9. In paragraph 8, The mass ratio of the carbon tube aggregate to the acidic solution is (0.1 to 100):1; and/or, the acidic solution is selected from one or more of nitric acid, sulfuric acid, and hydrochloric acid; and/or, the reaction temperature of stirring is 30 to 100℃, and the reaction time of stirring is 2 to 12h; and/or, washing is performed using pure water; drying is performed in an oven; and/or, a manufacturing method characterized by the drying temperature being 60 to 100℃ and the drying time being 2 to 48h.
  10. In paragraph 5, In step S2, the monomer of the polymer is selected from Formula I: Formula I A method for manufacturing, characterized in that, in the above formula I, A1 is selected from a benzene ring substituted with X, OH, NH2 or X, OH, NH2 ; X is selected from a halogen ion of F, Cl, Br and I; R1 , R2 , and R3 are each independently selected from at least one of H, unsubstituted or substituted phenyl, unsubstituted or substituted C1 - C20 alkyl, and unsubstituted or substituted C1 - C20 alkoxy; and the substituents of the substituted phenyl, the substituted C1 - C20 alkyl, and the substituted C1 - C20 alkoxy are each independently selected from at least one of halogen, OH, or NH2 .
  11. In paragraph 5 or 10, A method for manufacturing, characterized in that, in step S2, the polymer is selected from one or more of polyethylene glycol, aqueous polyurethane, polyvinyl alcohol, poly(1,1-difluoroethylene), fluorinated copolymer, polyimide, polyacrylic acid, polyacrylate, polymethyl methacrylate, phenol-formaldehyde resin, epoxy resin, or ionic resin.
  12. In paragraph 5, In step S2, the soft template is selected from a nonionic surfactant or an ionic surfactant; and/or, in step S2, the mass ratio of the carbon tube aggregate to the polymer is (0.1 to 10):1; and/or, in step S2, the solid content of the polymer in the solution is 20 to 100%; and/or, in step S2, the solution penetrates into the carbon tube aggregate under negative pressure conditions; and/or, in step S2, the curing temperature is 80 to 200℃ and the curing time is 0.5 to 50h; A manufacturing method characterized by obtaining a carbon tube composite carbon material by evaporating the solvent after curing in step S2, and/or, in step S2.
  13. In Paragraph 12, In step S2, the nonionic surfactant is selected from polyoxyethylene-polyoxypropylene copolymers; and/or, the ionic surfactant is selected from hexadecyl trimethylammonium bromide and/or sodium dodecylsulfonate; and/or, the above sound pressure condition is -0.9 to -0.01 MPa, and the sound pressure duration is 0.5 to 10 h; and/or, further comprising positive pressure treatment after negative pressure; the positive pressure condition is 0.15–2 MPa, and the pressure holding time is 0.5–48 h; and/or, a manufacturing method characterized in that the mass ratio of the carbon tube aggregate to the polymer is 1:3.
  14. In paragraph 5, A manufacturing method characterized in that, in step S3, the carbonization treatment comprises reacting the carbon tube composite carbon material at a high temperature under a protective gas.
  15. In Paragraph 14, The protective gas for the above carbonization treatment is selected from one or more of nitrogen, neon, argon, krypton, xenon, and radon; and/or, the flow rate of the above-mentioned protective gas is 1 to 20 L/min; and/or, the temperature of the high-temperature reaction is 500 to 1000℃; and/or, the time of the high-temperature reaction is 1 to 30 h; and/or, the heating rate of the above high-temperature reaction is 1 to 10℃/min; and/or, a post-treatment step after the high-temperature reaction: a method of manufacturing characterized by further including a step of lowering the temperature to room temperature.
  16. As silicon-carbon, The silicon-carbon raw material comprises a porous composite elastomer according to any one of claims 1 to 4, further comprises silicon nanoparticles, and is characterized in that the silicon nanoparticles are inserted into the porous composite elastomer.
  17. In Paragraph 16, It includes one or more of the following features b1) to b6), b1) The specific surface area of the silicon-carbon is <20 m² /g; b2) The D 50 of the silicon-carbon is <20μm; b3) The tap density of the silicon-carbon above is 0.5~2 g/ cm³ and; b4) The content of the silicon nanoparticles is 30–70% of the total mass of silicon-carbon; b5) The resistivity of the silicon-carbon above is <20Ω·cm; b6) Silicon-carbon characterized by having a specific capacity of >1200 mAh/g, an initial Coulomb efficiency of >89%, a capacity retention rate of >85% after 500 cycles, and a 4C/1C rate capability of >90%.
  18. A method for manufacturing silicon-carbon according to any one of claims 16 to 17, A manufacturing method comprising the step of obtaining silicon-carbon by vapor deposition of a porous composite elastomer and a silicon source-containing gas in a high-temperature environment.
  19. In Paragraph 18, The above high-temperature environment is a deposition furnace, the high-temperature is 300–600℃, and the temperature holding time is 1–50h; and/or, the silicon source gas is selected from one or more of silane, disilane, dichlorosilane, and trichlorosilane; and/or, the silicon source-containing gas further comprises a carbon source gas; and/or, a manufacturing method characterized by the vapor deposition time being 1 to 50 h.
  20. In Paragraph 19, The internal pressure of the above deposition furnace is 5 to 10 MPa, and the heating rate is 1 to 5 ℃/min; and/or, the carbon source gas is selected from alkane gases having a decomposition temperature of 600°C or lower; and/or, where the silicon source-containing gas contains only the silicon source gas, the gas flow rate is 1 to 20 L/min; and/or, where the silicon source-containing gas includes silicon source gas and carbon source gas, based on the total volume of the gas, the volume ratio of the silicon source gas is 70–99% and the volume ratio of the carbon source gas is 1–30%; and/or, where the silicon source-containing gas includes silicon source gas and carbon source gas, the gas flow rate is 5 to 20 L/min; and/or, a manufacturing method characterized by the vapor deposition time being 10 to 30 h.

Description

Porous composite elastomer, silicon-carbon, and its manufacturing method and applications The present application relates to the field of battery negative electrode technology, and in particular to porous composite elastomers, silicon-carbon, and methods for manufacturing the same and applications. Since silicon possesses a very high theoretical lithium insertion capacity and appropriate lithium extraction/insertion potential, it is evident that silicon-based anode materials are the ideal next-generation lithium-ion battery anode materials following graphite. However, silicon has very low electrical conductivity and ion diffusion coefficients. During the lithium extraction/insertion process, silicon undergoes severe volume expansion (>300%), leading to material cracking and pulverization, as well as delamination from the current collector, which causes a rapid decrease in capacity and a decline in cycle performance. While prior art composites using carbon materials with silicon can mitigate silicon volume expansion to some extent and improve cycle performance, such simple physical composites of silicon and carbon cannot guarantee the ion transport performance of the composite material. Patent (CN114420928A) discloses the formation of a core-shell silicon-carbon composite material using carbon nanotubes, graphene, and nanosilicon as core materials and coating the outer layer with soft carbon. While carbon nanotubes and graphene can enhance the ion transport capability of the composite material, the composite of carbon nanotubes, graphene, and silicon formed by polishing cannot guarantee composite uniformity, and thus cannot guarantee good bulk ion transport performance. Furthermore, silicon exists in a micrometer form, and severe volume expansion occurs during the lithium extraction/insertion process, causing a rapid deterioration in the battery's cycle performance. The patent (CN115663131A) describes a method for depositing nanosilicon on pelleted carbon nanotubes using CVD vapor deposition. While the reduction in silicon size mitigates volume expansion, the pores of the spherical carbon nanotubes after molding are very large, causing silicon to easily aggregate during the deposition process. Furthermore, the difference in hardness between the carbon nanotubes and silicon is significant, which can lead to cracking in the material during the rolling process for manufacturing electrode sheets. Additionally, volume expansion causes the material to pulverize during the lithium extraction/insertion process, resulting in a rapid decline in cycle performance. Considering the disadvantages of the aforementioned prior art, the object of the present application is to provide a porous composite elastomer, silicon-carbon, and a method for manufacturing the same and applications. To realize the aforementioned objectives and other related objectives, the present invention comprises the following technical solutions. A first aspect of the present application provides a porous composite elastomer having a porous structure, wherein the porous composite elastomer comprises a flexible body and a rigid body that interpenetrate each other, wherein the material of the flexible body comprises carbon nanotubes, and the rigid body is hard carbon. In any embodiment of the present application, the porous composite elastomer contains uniformly distributed micropores and/or mesopores. In any embodiment of the present application, the mass ratio of the flexible body to the rigid body is (0.01 to 2):1. Preferably, the mass ratio of the flexible body to the rigid body is (0.8 to 1.2):1. In any embodiment of the present application, the average pore size of the porous composite elastomer is <15 nm, and preferably 1.8 to 10 nm. In any embodiment of the present application, the total pore volume of the porous composite elastomer is 0.2 to 1.5 cm³ /g, and preferably 0.4 to 1.1 cm³ /g. In any embodiment of the present application, the specific surface area of the porous composite elastomer is >200 m² /g, and preferably >700 m² /g. In any embodiment of the present application, the D 50 of the porous composite elastomer is <30 μm, and preferably <20 μm. In any embodiment of the present application, the tap density of the porous composite elastomer is 0.1 to 1.0 g/ cm³ , and preferably 0.2 to 0.7 g/ cm³ . In any embodiment of the present application, the resistivity of the porous composite elastomer is <5 Ω·cm, preferably <0.5 Ω·cm, and more preferably <0.05 Ω·cm. In any embodiment of the present application, the pore size concentration of the porous composite elastomer is <7, and preferably 0.5 to 5. A second aspect of the present application provides a method for manufacturing the aforementioned porous composite elastomer, said manufacturing method, Preparation of carbon tube aggregates: Step S1 of preparing carbon tube aggregates by molding carbon nanotubes; Manufacturing of carbon tube composite carbon material: Step S2, in which carbon tube