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CN-121991715-A - Special negative electrode petroleum coke for power lithium battery and preparation method and application thereof

CN121991715ACN 121991715 ACN121991715 ACN 121991715ACN-121991715-A

Abstract

The invention belongs to the technical field of lithium ion battery cathode materials, and particularly discloses a special cathode petroleum coke for a power lithium battery as well as a preparation method and application thereof. The preparation method of the petroleum coke comprises the steps of (1) carrying out solid removal treatment on catalytic cracking slurry oil to obtain solid removal catalytic slurry oil, (2) mixing the solid removal catalytic slurry oil with vacuum residuum according to a certain proportion to obtain a mixed raw material, (3) carrying out coking reaction on the mixed raw material to obtain the high-quality low-sulfur petroleum coke with anisotropic content of more than or equal to 98%, mosaic structure content of less than 30%, fibrous structure content of less than or equal to 70% and less than 80%, graphitization degree of more than or equal to 90%, and after graphitization, the first discharge specific capacity of the anode material is more than or equal to 350mAh/g, and the first charge-discharge efficiency is more than or equal to 90%. The low-sulfur petroleum coke with excellent microstructure is prepared by regulating and controlling the composition of the delayed coking raw materials, can be used for preparing high-capacity power lithium battery cathode materials, and has the characteristics of low cost, simple process flow and equipment, controllable process conditions, easiness in realization of industrialization and the like.

Inventors

  • TIAN LINGYAN
  • WANG HUA
  • WEI JUN
  • DONG YUEHUI
  • ZHU LUXIN

Assignees

  • 中石油克拉玛依石化有限责任公司
  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. The preparation method of the special negative electrode petroleum coke for the power lithium battery is characterized by comprising the following steps of: (1) The catalytic cracking slurry oil is subjected to solid removal treatment to obtain solid removal catalytic slurry oil; (2) Mixing the solid-removed catalytic slurry oil obtained in the step (1) with vacuum residuum according to a certain proportion to obtain a mixed raw material; (3) And (3) carrying out coking reaction on the mixed raw material obtained in the step (2) to obtain the petroleum coke.
  2. 2. The method for preparing the special negative electrode petroleum coke for the power lithium battery as claimed in claim 1, wherein in the step (1), the sulfur content of the catalytic cracking slurry oil is less than or equal to 0.3wt%, the asphaltene content is less than or equal to 1.0wt% and the ash content is more than or equal to 0.5wt%; and/or the solid removing treatment comprises any one or more of membrane filtration solid removing, centrifugal sedimentation solid removing and reduced pressure distillation solid removing, and preferably reduced pressure distillation solid removing is adopted; And/or the 95% distillation temperature of the de-solidified catalytic slurry oil is 480-500 ℃, and the solid content of the de-solidified slurry oil is not more than 0.01wt%.
  3. 3. The method for preparing the special negative electrode petroleum coke for the power lithium battery as claimed in claim 1, wherein in the step (2), the sulfur content of the vacuum residue is less than or equal to 0.3wt%, the asphaltene content is less than or equal to 1.0wt% and the ash content is less than or equal to 0.1wt%.
  4. 4. The preparation method of the special negative electrode petroleum coke for the power lithium battery as claimed in claim 1, wherein the mass ratio of the solid removal catalytic slurry oil to the vacuum residue is 2:8-8:2.
  5. 5. The method for preparing the special negative electrode petroleum coke for the power lithium battery as claimed in claim 1, wherein in the step (3), the coking reaction temperature is 480-520 ℃, the pressure is 0.01-0.08 mpa, and the coking time is 4-6 h.
  6. 6. The special negative electrode petroleum coke for the power lithium battery is characterized in that the anisotropic content is more than or equal to 98%, the mosaic structure content is more than or equal to 10% and less than or equal to 30%, and the fiber structure content is more than or equal to 70% and less than or equal to 80% based on the volume fraction of an optical structure.
  7. 7. A special negative electrode petroleum coke for a power lithium battery, which is characterized by being prepared by the method according to any one of claims 1-5.
  8. 8. The artificial graphite is prepared by calcining and graphitizing the petroleum coke according to claim 6 or 7, wherein the calcining temperature is 800-1200 ℃ and the time is 2-4 hours, and the graphitizing temperature is 2800-3000 ℃ and the time is 1-3 hours.
  9. 9. An electrode comprising a copper foil and a mixed slurry applied to the surface of the copper foil, the mixed slurry comprising the artificial graphite of claim 8.
  10. 10. The lithium ion battery is characterized by comprising a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, wherein the negative electrode plate is formed by punching the electrode according to claim 9 through a die.

Description

Special negative electrode petroleum coke for power lithium battery and preparation method and application thereof Technical Field The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a special cathode petroleum coke for a power lithium battery as well as a preparation method and application thereof. Background Along with the development of technology, lithium batteries are increasingly used in people's life by virtue of the outstanding advantages of high voltage, high energy density, good cycle performance, low self-discharge and the like. Lithium ion batteries of various industries such as electric automobiles, mobile phones, unmanned aerial vehicles, electronic watches, notebook computers, game machines, aerospace and the like are widely visible. Research on lithium ion batteries has been started in the seventh and eighties of the 20 th century, and when the batteries are charged, the applied potential forces lithium ions to be free from the positive electrode compound and to be intercalated into the negative electrode carbon with a lamellar structure, and when the batteries are discharged, the lithium ions are separated from the negative electrode carbon and are combined with the positive electrode compound again. The movement of lithium ions between the positive electrode and the negative electrode generates current, and provides energy for related equipment. The end with lower potential in the lithium ion battery is called a cathode, and plays an oxidation role in the primary battery. The material required for the negative electrode in the lithium battery is a negative electrode material. The negative electrode material is one of four key materials of the lithium battery, accounts for 8% -10% of the manufacturing cost of the whole lithium battery, is used as a carrier of lithium ions and electrons in the charging process of the lithium battery, plays a role in energy storage and release, and is one of key factors for judging the performance of the lithium battery. The cathode materials which are researched and widely applied to the lithium ion battery mainly comprise a carbon system and a non-carbon system, and the carbon system materials occupy more than 98% of the cathode market. The carbon system mainly comprises artificial graphite and natural graphite, and the natural graphite has the advantages of low cost and high specific capacity, but has poor compatibility with electrolyte, and the graphite layer is easy to peel off along with intercalation of solvated lithium ions in the charging process, so that the cycle life is lower, and the safety performance is poor. The artificial graphite has more excellent cycle performance, safety performance and charge-discharge multiplying power, becomes the main stream of the negative electrode material market, improves the market share year by year, and has the market share stabilized above 80%. The main sources of the artificial graphite cathode material are needle coke and low-sulfur petroleum coke. Needle coke and petroleum coke are main byproducts of thermal reaction post-condensation of heavy petroleum fractions, and the artificial graphite anode material is prepared through a series of processes of pretreatment, granulation, high-temperature graphitization, screening and the like. The needle Jiao Ji cathode material is a high-end product in the current market, has high capacity, high compaction density and good multiplying power performance, is suitable for quick charge and quick discharge, but has high product cost, and is mainly used in the fields of power batteries with high performance requirements and 3C digital codes with relatively insensitive price. The capacitance, the first coulombic efficiency and the compaction density of the petroleum coke-based negative electrode material are lower than those of the needle-shaped Jiao Ji negative electrode material, and the petroleum coke-based negative electrode material is mainly applied to the requirements of the middle-low end field. The needle coke is produced by using high-quality aromatic hydrocarbon rich raw materials with low sulfur, low ash, low metal and low asphaltene through a temperature and pressure varying delayed coking process and the like, has the advantages of low sulfur, low ash, low resistivity, high true density, low thermal expansion coefficient, easy graphitization and the like, but has higher requirements on raw materials and processes, limited raw material sources and higher cost price. The petroleum coke is a byproduct obtained by directly carrying out delayed coking by taking inferior petroleum residual oil as a raw material, and because the residual oil raw material is not pretreated, the sulfur content, ash content and metal content of the petroleum coke depend on the properties of the raw material, and the graphitization performance and specific capacity of the petroleum coke are lower than those of needle coke. Ch