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CN-121974343-A - Biomass-based porous carbon material, and preparation method and application thereof

CN121974343ACN 121974343 ACN121974343 ACN 121974343ACN-121974343-A

Abstract

The invention relates to a biomass-based porous carbon material, a preparation method and application thereof, wherein the preparation method comprises the following steps of mixing lignocellulose-based biomass, a modifier, an alkaline catalyst and water, and performing a first crosslinking reaction at 150-250 ℃ in a closed reactor to obtain an intermediate product, wherein the modifier is selected from at least one of phenolic hydroxyl-containing organic matters, aldehyde-containing organic matters or sugar alcohols; mixing lignocellulose-based biomass with the intermediate product, performing a second crosslinking reaction at 300-400 ℃ in a closed reactor, then drying to obtain a carbon precursor, mixing the carbon precursor with an alkali metal activator, and then calcining and washing to obtain the biomass-based porous carbon material. The preparation method can prepare the biomass-based porous carbon material with high mechanical strength, and further can be used for preparing the silicon carbon material with high mechanical property.

Inventors

  • LIN NING
  • QIAN YONG

Assignees

  • 甬江实验室

Dates

Publication Date
20260505
Application Date
20251229

Claims (10)

  1. 1. The preparation method of the biomass-based porous carbon material is characterized by comprising the following steps of: mixing lignocellulose-based biomass, a modifier, an alkaline catalyst and water, and performing a first crosslinking reaction at 150-250 ℃ in a closed reactor to obtain an intermediate product, wherein the modifier is selected from at least one of phenolic hydroxyl-containing organic matters, aldehyde-containing organic matters or sugar alcohols; Mixing lignocellulose-based biomass with the intermediate product, performing a second crosslinking reaction at 300-400 ℃ in a closed reactor, and then drying to obtain a carbon precursor; and mixing the carbon precursor with an alkali metal activator, and then calcining and washing to obtain the biomass-based porous carbon material.
  2. 2. The method for preparing a biomass-based porous carbon material according to claim 1, wherein in the first crosslinking reaction, the mass ratio of the lignocellulose-based biomass to the modifier is 1:2-1:5; And/or the mass ratio of the lignocellulose-based biomass to the alkaline catalyst is 1:1-1:3; and/or the mass ratio of the lignocellulose-based biomass to the water is 1:3-1:7.
  3. 3. The method for preparing a biomass-based porous carbon material according to claim 1, wherein in the second crosslinking reaction, the mass ratio of the lignocellulose-based biomass to the intermediate product is 1:1-1:3; and/or in the calcining step, the mass ratio of the carbon precursor to the alkali metal activator is 1:1-1:3.
  4. 4. The preparation method of the biomass-based porous carbon material according to claim 1, wherein the temperature rise rate of the first crosslinking reaction is 2-7 ℃ per minute, and the heat preservation time is 8-15 hours; And/or the temperature rising rate of the second crosslinking reaction is 2-7 ℃ per minute, and the heat preservation time is 8-15 h.
  5. 5. The method for preparing a biomass-based porous carbon material according to claim 1, wherein the step of calcining is performed in a protective atmosphere, the calcining temperature is 700 ℃ to 1000 ℃ and the calcining time is 3h to 6h.
  6. 6. The method of producing a biomass-based porous carbon material according to claim 1, wherein the lignocellulose-based biomass is selected from at least one of bamboo, straw, pine, poplar or oak; And/or the modifier is at least one of alkali lignin, lignin phenol, gallic acid, phenol, hydroquinone, formaldehyde, furfural, glutaraldehyde, D-glucitol or maltitol; and/or the alkaline catalyst is at least one of ammonia water, potassium hydroxide, triethylamine, diethanolamine or sodium carbonate; And/or the alkali metal activator is at least one selected from potassium hydroxide, sodium hydroxide or lithium hydroxide.
  7. 7. A biomass-based porous carbon material produced using the production method of a biomass-based porous carbon material according to any one of claims 1 to 6.
  8. 8. A silicon-carbon material, characterized in that the silicon-carbon material adopts the biomass-based porous carbon material as described in claim 7 as a carbon substrate.
  9. 9. A negative electrode sheet, characterized in that the negative electrode sheet uses the silicon carbon material as claimed in claim 8.
  10. 10. A battery, characterized in that the battery uses the negative electrode sheet according to claim 9.

Description

Biomass-based porous carbon material, and preparation method and application thereof Technical Field The invention relates to the technical field of batteries, in particular to a biomass-based porous carbon material, and a preparation method and application thereof. Background Silicon materials are considered ideal choices for next-generation anode materials because of their extremely high theoretical specific capacities. However, silicon undergoes severe volume expansion during charge and discharge, resulting in collapse of the negative electrode structure, severely damaging the cycle stability and the service life of the battery. In order to effectively inhibit the volume expansion of silicon and improve the comprehensive performance of the battery, a silicon-carbon material formed by compounding silicon and a carbon material becomes an important technical route. Among the numerous carbon materials, biomass-based porous carbon is an ideal carrier because of its advantages of wide sources, low cost, environmental friendliness, and natural abundance of pore structures. These pore structures not only provide a large number of sites for the loading of silicon, but also buffer the volumetric expansion of silicon to some extent and promote electrolyte infiltration and lithium ion transport. However, since biomass itself has the characteristics of loose structure, many defects, etc., the fiber network inside the biomass is easy to shrink and collapse in the carbonization process, and a carbon skeleton with high mechanical strength is difficult to form. When the porous carbon with insufficient mechanical strength is used for depositing silicon by CVD (chemical vapor deposition), under the action of great stress of repeated expansion and contraction of silicon, the carbon skeleton is extremely easy to generate structural deformation, fracture and even collapse, which directly leads to the falling of the loaded silicon particles, damages the integrity of the silicon-carbon material, leads the electrochemical performance of the silicon-carbon material to be rapidly deteriorated, and restricts the large-scale application of the bio-based porous carbon in the silicon-carbon anode material. Disclosure of Invention Based on this, it is necessary to provide a biomass-based porous carbon material, a preparation method and application thereof, wherein the preparation method can prepare the biomass-based porous carbon material with high mechanical strength, and further can be used for preparing the silicon carbon material with high mechanical property. A method for preparing a biomass-based porous carbon material, comprising the following steps: mixing lignocellulose-based biomass, a modifier, an alkaline catalyst and water, and performing a first crosslinking reaction at 150-250 ℃ in a closed reactor to obtain an intermediate product, wherein the modifier is selected from at least one of phenolic hydroxyl-containing organic matters, aldehyde-containing organic matters or sugar alcohols; Mixing lignocellulose-based biomass with the intermediate product, performing a second crosslinking reaction at 300-400 ℃ in a closed reactor, and then drying to obtain a carbon precursor; and mixing the carbon precursor with an alkali metal activator, and then calcining and washing to obtain the biomass-based porous carbon material. In one embodiment, in the first crosslinking reaction, the mass ratio of the lignocellulose-based biomass to the modifier is 1:2-1:5; And/or the mass ratio of the lignocellulose-based biomass to the alkaline catalyst is 1:1-1:3; and/or the mass ratio of the lignocellulose-based biomass to the water is 1:3-1:7. In one embodiment, in the second crosslinking reaction, the mass ratio of the lignocellulose-based biomass to the intermediate product is 1:1-1:3; and/or in the calcining step, the mass ratio of the carbon precursor to the alkali metal activator is 1:1-1:3. In one embodiment, the temperature rising rate of the first crosslinking reaction is 2-7 ℃ per minute, and the heat preservation time is 8-15 hours; And/or the temperature rising rate of the second crosslinking reaction is 2-7 ℃ per minute, and the heat preservation time is 8-15 h. In one embodiment, the calcining step is performed in a protective atmosphere, wherein the calcining temperature is 700 ℃ to 1000 ℃ and the calcining time is 3 hours to 6 hours. In one embodiment, the lignocellulosic biomass is selected from at least one of bamboo, straw, pine, poplar, or oak; And/or the modifier is at least one of alkali lignin, lignin phenol, gallic acid, phenol, hydroquinone, formaldehyde, furfural, glutaraldehyde, D-glucitol or maltitol; and/or the alkaline catalyst is at least one of ammonia water, potassium hydroxide, triethylamine, diethanolamine or sodium carbonate; And/or the alkali metal activator is at least one selected from potassium hydroxide, sodium hydroxide or lithium hydroxide. A biomass-based porous carbon material produced using the metho