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CN-122010089-A - Bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material and preparation method and application thereof

CN122010089ACN 122010089 ACN122010089 ACN 122010089ACN-122010089-A

Abstract

The invention discloses a bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material, a preparation method and application thereof, comprising a homogeneous graphite-like sub-crystalline carbon material, wherein the material is prepared from 3.71 percent 4.0 The large interlayer spacing of the a, the nearly parallel oriented carbon sheets, constitute homogeneous sub-crystalline features. When the homogeneous graphite-like sub-crystalline carbon material is used for the negative electrode of a sodium ion battery, the first coulomb efficiency reaches 94.4%, the first charge specific capacity reaches 353.5 mAh/g, and the performance is comparable to that of a lithium-calcium graphite negative electrode. The preparation method of the invention uses bamboo as a precursor, uses a graphite container and graphite powder as double crystal seeds at low temperature to fully induce macroscopic bamboo continuum to generate an oxygen-containing six-membered ring network intermediate product, and uses the graphite container as single crystal seeds at high temperature to induce intermediate products with proper grain sizes to prepare the graphite-like sub-crystalline carbon material with uniform structure. The method takes the bamboo source as the raw material, has simple process and low energy consumption, and has remarkable industrialization potential.

Inventors

  • LIU YONG
  • LIU MING

Assignees

  • 中山大学

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. A bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material is characterized in that the phase of the bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material is graphite-like sub-crystalline carbon, the structure of the bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material is a homogeneous structure formed by nearly parallel carbon sheets with consistent long-range orientation, and the (002) plane surface spacing d 002 is 3.71-4.0A.
  2. 2. The method for preparing the bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material as claimed in claim 1, which is characterized by comprising the following steps: Placing a bamboo material into a sealed graphite container, filling graphite powder into the sealed graphite container, and performing a first induced growth reaction to obtain a bamboo-based sub-crystalline carbon intermediate product; Crushing the bamboo-based sub-crystalline carbon intermediate product to obtain a powdery bamboo-based sub-crystalline carbon intermediate product, and removing impurities in the bamboo-based sub-crystalline carbon intermediate product to obtain a purified powdery bamboo-based sub-crystalline carbon intermediate product; And (3) putting the purified powdery bamboo-based sub-crystalline carbon intermediate product into a closed graphite container again, and carrying out a second induced growth reaction to obtain the bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material.
  3. 3. The method for preparing a bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material according to claim 2, wherein the reaction conditions of the first induced growth reaction include at least one of the following: a) The reaction temperature is 400-600 ℃; b) The heat preservation time is 1-3 h; c) Heating to a reaction temperature at a heating rate of 0.5-5 ℃ per minute; d) The reaction is carried out under a protective atmosphere.
  4. 4. The method for preparing a bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material according to claim 2, wherein the reaction conditions of the second induced growth reaction include at least one of the following: a) The reaction temperature is 1400-1600 ℃; B) The heat preservation time is 2-4 h; c) Heating to a reaction temperature at a heating rate of 0.5-5 ℃ per minute; d) The reaction is carried out under a protective atmosphere.
  5. 5. The method for preparing the bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material according to claim 2, wherein the particle size of the powdery bamboo-based sub-crystalline carbon intermediate product is 10-60 μm.
  6. 6. The method for preparing the bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material, as claimed in claim 2, is characterized by comprising the specific steps of immersing the powdery bamboo-based sub-crystalline carbon intermediate product in acid and/or alkali, and removing impurities in the powdery bamboo-based sub-crystalline carbon intermediate product.
  7. 7. The method for preparing a bamboo-based large-layer-spacing homogeneous graphite-like sub-crystalline carbon material according to claim 2, wherein the closed graphite container comprises one of a graphite crucible and a graphite boat; And/or the particle size of the graphite powder is 0.3-0.8 mu m.
  8. 8. The use of the bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material of claim 1 in a battery active material.
  9. 9. A battery negative electrode sheet, characterized in that the negative electrode sheet comprises a negative electrode current collector and a negative electrode active layer positioned on at least one side surface of the negative electrode current collector, and the negative electrode active layer comprises the bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material as claimed in claim 1.
  10. 10. A sodium ion battery comprising the battery negative electrode sheet of claim 9.

Description

Bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material and preparation method and application thereof Technical Field The invention belongs to the technical field of carbon materials, and particularly relates to a bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystalline carbon material, and a preparation method and application thereof. Background Compared with a lithium ion battery, the sodium ion battery relies on the core advantage of abundant sodium resource reserves, and has wide application prospect in the field of large-scale energy storage power stations. However, the development and development progress of the negative electrode material of the sodium ion battery are obviously lagged, and the negative electrode material has become a key bottleneck for limiting the performance breakthrough and industrialization landing of the sodium ion battery. The energy density of the full cell is mainly determined by the average working voltage difference between the positive electrode and the negative electrode and the matched reversible capacity at the active material level. When the full battery is in discharge operation, the negative electrode is in the sodium removing process. Therefore, when evaluating a carbon negative electrode material based on a half-cell test, efforts should be made to increase its reversible sodium removal capacity (first charge specific capacity= 'first discharge specific capacity x first coulombic efficiency'), increase the first charge capacity ratio of the low-voltage plateau region, and increase the first coulombic efficiency to maximize the full-cell energy density. For negative electrodes, a lower first charge capacity will reduce the energy density of the cell, while a lower first coulombic efficiency will result in irreversible loss of active sodium, which in practice must be compensated for by positive electrode overdose or pre-sodification designs, but this will significantly increase material costs and reduce the actual energy density of the cell. The hard carbon material prepared by taking biomass as a precursor has become a research hot spot of the negative electrode material of the sodium ion battery because of wide raw material sources, low cost and higher specific capacity (more than or equal to 300 mAh/g). However, the microstructure of the traditional biomass-based hard carbon is a disordered layer structure formed by staggered stacking of carbon sheets with random orientations and distorted shapes, and a large number of defects and holes exist at the same time. These disordered structures, defects and pores lead to irreversible intercalation/adsorption of sodium ions, which on the one hand results in a high-duty-cycle high potential ramp region capacity and on the other hand results in significant irreversible capacity loss, ultimately leading to a first coulomb efficiency far lower than that of the graphite negative electrode of a commercial lithium ion battery. In biomass raw materials, bamboo is widely regarded as sustainable biomass precursors for preparing sodium ion battery carbon anode materials because of short growth cycle, abundant resource reserves, easy collection and transportation, and compact arrangement of natural fibers. However, conventional pyrolysis processes typically result in hard carbon of disordered structure, which has limited performance. In the prior art, patent CN117658107A discloses a preparation method of bamboo-based hard carbon, in an electrochemical performance test of a sodium ion battery, the first coulomb efficiency of an embodiment is 81.1-89.8%, the first discharge specific capacity is 293.5-339.7 mAh/g, wherein, the embodiment 2 (89.8%) with the optimal first coulomb efficiency corresponds to 323.2 mAh/g of the first discharge specific capacity, and the embodiment 6 (339.7 mAh/g) with the optimal first discharge specific capacity corresponds to 81.1% of the first coulomb efficiency. In the industrial application of the sodium ion battery, the carbon anode material at least reaches the same level of lithium storage of the graphite anode of the lithium ion battery (according to the requirements of the national standard GB/T24533-2019 of the graphite anode material of the lithium ion battery, the initial coulomb efficiency of the graphite anode is more than or equal to 90 percent, and the specific graphite capacity is more than or equal to 340 mAh/g in the standard condition of the lithium ion battery industry (2024). Therefore, the development of the novel high-performance bamboo-based carbon negative electrode material with high first coulombic efficiency and high first charge specific capacity has important significance for the development and application of sodium ion batteries. Disclosure of Invention In order to overcome the problems of the prior art, one of the purposes of the present invention is to provide a bamboo-based large-layer-spacing homogeneous grap