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CN-122000313-A - Flexible self-supporting material and preparation method and application thereof

CN122000313ACN 122000313 ACN122000313 ACN 122000313ACN-122000313-A

Abstract

The invention belongs to the field of flexible battery energy storage, and relates to a flexible self-supporting material, a preparation method and application thereof. The flexible self-supporting material comprises a carbon nano tube film, a Si/Ge film and a liquid metal film which are sequentially arranged. The invention uses the carbon nano tube film as a flexible carrier, has good flexibility, mechanical property, electrical conductivity and ultra-light weight, can greatly reduce the proportion of inactive substances in the electrode, and improves the energy density of the electrode material. Meanwhile, si easily falls off from the traditional current collector Cu to cause the damage of an electrode structure, and the carbon nano tube film well improves the defect and improves the stability of an electrode material.

Inventors

  • WEI YANBIN
  • ZHU ZHENXING
  • ZHANG QI
  • Zhu Yukang
  • WEI FEI
  • ZHANG SHIJUN

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司
  • 清华大学

Dates

Publication Date
20260508
Application Date
20241108

Claims (12)

  1. 1. The flexible self-supporting material is characterized by comprising a carbon nano tube film, a Si/Ge film and a liquid metal film which are sequentially arranged.
  2. 2. The flexible self-supporting material of claim 1, wherein the liquid metal In the thin film of liquid metal is selected from at least one of gallium (Ga), indium (In), tin (Sn), in-Sn alloys, ga-In-Sn alloys, and metallic or non-metallic doped In-Sn alloys, ga-In-Sn alloys.
  3. 3. The flexible self-supporting material according to claim 2, wherein the ratio of the mass of In to the total mass of other metals In the alloy is 6-12:1, more preferably 8-10:1; Preferably, the liquid metal is an in—sn alloy.
  4. 4. The flexible self-supporting material according to claim 1, wherein the carbon nanotube film is used as a flexible substrate, the thickness of the carbon nanotube film is 5-20 μm, the thickness of the Si/Ge film is 0.2-3 μm, and the thickness of the liquid metal film is 0.1-0.3 μm.
  5. 5. The flexible self-supporting material of any one of claims 1-4, wherein the flexible self-supporting material is free of conductive agents and binders.
  6. 6. A method of preparing a flexible self-supporting material as claimed in any one of claims 1 to 5, comprising the steps of: (1) Preparing a carbon nano tube film by a floating catalytic chemical vapor deposition method; (2) And sequentially preparing a Si/Ge film and a liquid metal film on the surface of the carbon nanotube film by a magnetron sputtering method to obtain the flexible self-supporting material.
  7. 7. The method of producing a flexible self-supporting material according to claim 6, wherein the step (1) comprises contacting a carbon source with a catalyst at a high temperature in the presence of hydrogen and an inert gas, continuously growing carbon nanotubes, collecting carbon nanotube aggregates, and press-molding to produce a carbon nanotube film.
  8. 8. The method for preparing a flexible self-supporting material according to claim 7, wherein the carbon source is acetylene, the catalyst is ferrocene, and the inert gas is argon; The content of the carbon source is 4-8wt% based on the total weight of the carbon source, hydrogen and inert gas; The weight ratio of the carbon source to the catalyst is 30-50:1; the volume ratio of the hydrogen to the inert gas is 1-3:1; the airspeed in the reaction process is 1500-2500 h -1 ; the high temperature is 1300-1550 ℃.
  9. 9. The method for preparing the flexible self-supporting material according to claim 6, wherein the sputtering condition comprises that a magnetron sputtering machine system is vacuumized for 0.5 multiplied by 10 -4 ～1.5×10 -4 Pa, sputtering gas is high-purity argon, and working pressure is 0.5-1.5 Pa.
  10. 10. The method of preparing a flexible self-supporting material as claimed in claim 6, wherein the sputtering step comprises pre-sputtering a target including a Si/Ge target and a liquid metal target, then sputtering the Si/Ge target, depositing a Si/Ge film on the carbon nanotube film, then sputtering the liquid metal target, and depositing a layer of liquid metal on the deposited Si/Ge film.
  11. 11. The method for preparing the flexible self-supporting material according to claim 10, wherein the sputtering condition of the Si/Ge target material comprises 100-200W of power and 50-100 min of time, The sputtering condition of the liquid metal target material comprises that the power is 10-30W and the time is 10-30 min.
  12. 12. Use of a flexible self-supporting material according to any of claims 1-5 as electrode material, preferably in a flexible battery.

Description

Flexible self-supporting material and preparation method and application thereof Technical Field The invention belongs to the field of flexible battery energy storage, and particularly relates to a flexible self-supporting material, a preparation method and application thereof. Background With the continuous development of society, the demand for energy will be increasing. Lithium ion batteries have received extensive research and attention as an energy storage device. Due to their numerous advantages, they are widely used in various electronic devices. Currently, commercial graphite has failed to meet the practical demands of high energy density lithium ion batteries. Silicon (Si) has the advantages of ultrahigh theoretical capacity (3579 mA h g -1,Si15Li4), low price and the like, and is one of the most promising lithium ion battery cathode materials. However, si has a large volume change, unstable solid electrolyte membranes, and poor electrical conductivity, and these have been major problems that limit its use as a negative electrode material for lithium ion batteries. Strategies to improve the electrochemical properties of Si mainly include preparing Si of different nanostructures, compounding with other materials, selecting new binders and electrolytes. Unlike conventional batteries, flexible batteries require flexibility for each component, and the key to constructing a flexible battery is the combination of a flexible current collector and a high specific capacity active material. Due to the large volume change, si is easily detached from the conventional copper current collector and damages the electrode structure. Some studies have improved the stability of the electrode by modifying the copper current collector, but the improvement of this method is limited. Carbon nanotube films have good flexibility, mechanical properties, and electrical conductivity and are often used as flexible electrode carriers. It has ultra-light weight and can greatly reduce the proportion of inactive substances in the electrode. Research into carbon nanotubes has made tremendous progress in yield, precise structural control, and performance optimization over the past several decades. The carbon nanotube film is gradually moving from laboratory to industrialization, and is more similar to practical application. The liquid metal (Ga, in, sn, etc.) is liquid at normal temperature, has excellent conductivity, flexibility, fluidity, etc., and can adapt to volume expansion and repair the surface of the electrode. Disclosure of Invention The invention aims to provide a flexible self-supporting material and a preparation method thereof, wherein the flexible self-supporting material has good flexibility and excellent electrochemical performance, has great application potential in the field of battery energy storage, and is simple and convenient in preparation method and suitable for other high-capacity electrode materials. A first aspect of the present invention provides a flexible self-supporting material comprising a carbon nanotube film, a Si/Ge film, and a liquid metal film, disposed in that order. Optionally, the liquid metal In the liquid metal film is selected from at least one of gallium (Ga), indium (In), tin (Sn), in-Sn alloy, ga-In-Sn alloy, and metal or non-metal doped In-Sn alloy, ga-In-Sn alloy. Optionally, the ratio of the mass of In the alloy to the total mass of other metals is 6-12:1, more preferably 8-10:1. Optionally, the liquid metal is an in—sn alloy. Optionally, the thickness of the carbon nanotube film is 5-20 μm, the thickness of the Si or Ge film is 1-3 μm, and the thickness of the liquid metal film is 0.1-0.3 μm. Optionally, the flexible self-supporting material is free of conductive agents and binders. A second aspect of the present invention provides a method for preparing the flexible self-supporting material described above, comprising the steps of: (1) Preparing a carbon nano tube film by a floating catalytic chemical vapor deposition method; (2) And sequentially preparing a Si/Ge film and a liquid metal film on the surface of the carbon nanotube film by a magnetron sputtering method to obtain the flexible self-supporting material. Optionally, the step (1) comprises the steps of contacting a carbon source with a catalyst at a high temperature in the presence of hydrogen and inert gas, continuously growing carbon nanotubes, collecting carbon nanotube aggregates, and performing compression molding to prepare the carbon nanotube film. Optionally, the carbon source is acetylene, the catalyst is ferrocene, and the inert gas is argon. Optionally, the content of the carbon source is 4-8wt% based on the total weight of the carbon source, hydrogen and inert gas. Optionally, the weight ratio of the carbon source to the catalyst is 30-50:1. Optionally, the volume ratio of the hydrogen to the inert gas is 1-3:1. Optionally, the space velocity of the reaction process is 1500-2500 h -1. Optionally, the high te