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CN-121975540-A - Ethylene tar-based liquid phase coated asphalt for lithium battery fast charging negative electrode and preparation method thereof

CN121975540ACN 121975540 ACN121975540 ACN 121975540ACN-121975540-A

Abstract

The invention discloses ethylene tar-based liquid phase coated asphalt for a lithium battery quick-charge anode and a preparation method thereof, relates to the technical field of new energy materials, and solves the technical problems of high quinoline insoluble content, poor fluidity, poor battery quick-charge performance and low added value of ethylene tar in the traditional coated asphalt. The preparation method takes ethylene tar as a raw material, aromatic components with specific distillation ranges are obtained through three-stage rectification and fine segmentation, the aromatic components and the reactive heavy components are homogenized and prepared, and then catalytic crosslinking reaction is carried out under the atmosphere of a catalyst and oxygen to obtain the ethylene tar-based liquid phase coated asphalt. The coated asphalt prepared by the invention is in a liquid state at normal temperature, the content of quinoline insoluble substances is less than or equal to 0.1%, when the coated asphalt is applied to the coating of a lithium battery fast-charging negative electrode, the 2C/0.5C capacity retention rate is more than or equal to 93%, the primary efficiency is more than or equal to 92%, the comprehensive utilization rate of ethylene tar is more than or equal to 98%, the product yield is more than or equal to 56%, the process is continuous, the industrialization is easy, and the environment-friendly sustainable development concept is met.

Inventors

  • LIU XINYU
  • XU XIAOQIANG
  • ZHOU LINQIANG
  • WU YANYU

Assignees

  • 成都昱泰新材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. The preparation method of the ethylene tar-based liquid phase coated asphalt for the quick charge cathode of the lithium battery is characterized by comprising the following steps of: raw material rectification and separation, namely finely separating ethylene tar through a three-stage rectification system, cutting and collecting aromatic components with two distillation ranges of 180-220 ℃ and 240-260 ℃ to obtain a reaction heavy component; Homogenizing the fraction, namely mixing the aromatic components with the two distillation ranges in the step 1) with the heavy reaction component according to the mass ratio of 1 (0.5-2), and carrying out homogenizing reaction under the protection of inert gas to obtain a liquid phase coated asphalt precursor; And (3) carrying out catalytic crosslinking reaction on the liquid-phase coated asphalt precursor in the presence of a catalyst and an oxygen-containing atmosphere to obtain the ethylene tar-based liquid-phase coated asphalt.
  2. 2. The preparation method according to claim 1, wherein the rectification process of the three-stage rectification system in the step 1) is that ethylene tar is preheated and then enters a rectification first tower, fuel oil fractions are separated from the tower top, a tower bottom material enters a rectification second tower, light components are separated from the tower top, the second tower bottom material part is sent to a reaction system and enters a rectification third tower partially, high-boiling-range fuel oil fractions are separated from the tower top of the rectification third tower, the reaction heavy components are obtained from the tower bottom, and aromatic components at 180-220 ℃ and 240-260 ℃ are collected from the tower top of the rectification second tower and/or the rectification third tower.
  3. 3. The preparation method according to claim 1, wherein the condition of the homogenizing reaction in the step 2) is that the reaction temperature is 120-160 ℃, the stirring speed is 300-800r/min, the reaction time is 1-4h, and the addition amount of the reaction heavy component is 5-15% of the total mass of the aromatic component.
  4. 4. The preparation method according to claim 1, wherein the catalyst in the step 3) is a metal oxide catalyst and/or a molecular sieve catalyst, and the addition amount of the catalyst is 0.1-1% of the total mass of the liquid phase coated asphalt precursor.
  5. 5. The preparation method according to claim 1, wherein the process conditions of the catalytic crosslinking reaction in the step 3) are that the reaction temperature is 300-360 ℃, the reaction pressure is 0.5-1.5MPa, the reaction time is 2-8h, the oxygen-containing atmosphere is air with the oxygen volume fraction of 0-2%, and the air flow rate is 1-3L/(min.kg) of the liquid-phase coated asphalt precursor.
  6. 6. The process according to any one of claims 1 to 5, wherein the ethylene tar in step 1) has an aromatic compound content of 80% or more and a total content of sulfur, nitrogen and ash of 0.5% or less.
  7. 7. The method according to any one of claims 1 to 5, wherein the inert gas in step 2) is one or a mixture of two of nitrogen and argon.
  8. 8. An ethylene tar-based liquid phase coated asphalt for a lithium battery fast charge cathode, which is characterized in that the preparation method of any one of claims 1-7 is adopted, the coated asphalt is liquid at normal temperature, the quinoline insoluble content is less than or equal to 0.1%, and the coking value is 18-28%.
  9. 9. The application of the ethylene tar-based liquid phase coated asphalt in the lithium battery negative electrode material is characterized in that the coated asphalt is coated on the surface of a graphite negative electrode material, and the lithium battery quick-charge negative electrode material is obtained after carbonization, wherein the carbonization condition is that the carbonization temperature is 900-1100 ℃, the carbonization time is 1-3h, the carbonization atmosphere is inert gas atmosphere, and the coating amount of the coated asphalt is 8-12% of the mass of the graphite negative electrode material.
  10. 10. A lithium battery fast-charging anode material is characterized by comprising a graphite base material and a carbon coating layer coated on the surface of the base material, wherein the carbon coating layer is formed by carbonizing the ethylene tar-based liquid phase coated asphalt according to claim 8, the capacity retention rate of 2C/0.5C of the anode material is more than or equal to 93%, the initial coulomb efficiency is more than or equal to 92%, and the capacity retention rate of 100 times of circulation is more than or equal to 95%.

Description

Ethylene tar-based liquid phase coated asphalt for lithium battery fast charging negative electrode and preparation method thereof Technical Field The invention relates to the technical field of new energy materials, in particular to ethylene tar-based liquid phase coated asphalt for a lithium battery fast-charging negative electrode and a preparation method thereof. Background The lithium ion battery is widely applied to the fields of new energy automobiles, energy storage equipment and the like due to the advantages of high energy density, long cycle life and the like, and along with the expansion of application scenes, the market has higher requirements on the quick charge performance and the cycle stability of the lithium battery. The graphite material is a main stream negative electrode material of a lithium battery, the surface coating modification is a key means for improving the electrochemical performance of the battery, the coated asphalt is used as a core coating agent, an amorphous carbon protective layer can be formed on the surface of graphite, the side reaction of electrolyte and graphite is reduced, and the stripping of a graphite sheet layer in the charge-discharge process is inhibited, so that the first coulomb efficiency, the reversible capacity and the cycle life of the battery are improved. The existing production process of the traditional lithium battery cathode coated asphalt has the technical defects that firstly, the quinoline insoluble content of the product is generally higher than 5%, so that the coated asphalt is poor in fluidity, poor in wettability to graphite, uneven, cracking and the like are easy to occur in a coating layer, the quick charging performance of the battery is seriously affected, secondly, the production process is mainly intermittent operation, the product quality fluctuation is large, the product yield is lower than 40%, the production cost is high, thirdly, the raw material is mainly polycyclic aromatic hydrocarbon with compact structure, almost no branched chain free radical is contained, the raw material adaptability is poor, and the optimization of the performance of the coated asphalt is difficult to realize through structural regulation. Ethylene tar is a byproduct of ethylene industrial production, the aromatic compound content of the ethylene tar is up to more than 80%, the sulfur, nitrogen and ash content of the ethylene tar are extremely low, and the ethylene tar is an ideal raw material for preparing coated asphalt, but the ethylene tar is mainly used as a fuel oil or carbon black production raw material at present, the resource added value is low, and high-value utilization is not realized. In the prior art, an attempt is also made to prepare the coated asphalt by using ethylene tar, but most of the schemes are simple mixing and crosslinking, the ethylene tar is not subjected to fine fraction segmentation, the accurate regulation and control of the molecular structure of the coated asphalt cannot be realized, the prepared product still has the problems of poor fluidity and poor quick charge performance, and the application requirements of the lithium battery quick charge anode are difficult to meet. Therefore, the development of the liquid phase coated asphalt which is based on the fine utilization of ethylene tar, low quinoline insoluble matter and high fluidity and can remarkably improve the quick charge performance of the lithium battery and the preparation method thereof becomes a research focus in the field of current new energy materials. Disclosure of Invention In order to overcome the defects of the performance and the process of the lithium battery coated asphalt in the prior art, the invention discloses the ethylene tar-based liquid phase coated asphalt for the quick charge negative electrode of the lithium battery and the preparation method thereof, which can effectively solve the technical problems that the ethylene tar-based coated asphalt is not finely fractionated, the resource utilization is low-efficiency, the product performance is poor and the like. In order to solve the technical problems, the technical scheme of the invention is as follows: A preparation method of ethylene tar-based liquid phase coated asphalt for a lithium battery fast-charging negative electrode comprises the following steps: raw material rectification and separation, namely finely separating ethylene tar through a three-stage rectification system, cutting and collecting aromatic components with two distillation ranges of 180-220 ℃ and 240-260 ℃ to obtain a reaction heavy component; Homogenizing the fraction, namely mixing the aromatic components with the two distillation ranges in the step 1) with the heavy reaction component according to the mass ratio of 1 (0.5-2), and carrying out homogenizing reaction under the protection of inert gas to obtain a liquid phase coated asphalt precursor; And (3) carrying out catalytic crosslinking reaction on the liquid-p