Search

CN-121991714-A - Special negative electrode petroleum coke for energy storage type lithium battery as well as preparation method and application thereof

CN121991714ACN 121991714 ACN121991714 ACN 121991714ACN-121991714-A

Abstract

The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to energy storage type special cathode petroleum coke for lithium batteries, and a preparation method and application thereof. The petroleum coke preparation method comprises the following steps of (1) mixing vacuum residuum and deoiled asphalt according to a certain proportion to obtain a mixed coking raw material, (2) carrying out coking reaction on the mixed coking raw material obtained in the step (1) to obtain the petroleum coke, wherein the anisotropic content is more than or equal to 95%, the mosaic structure content is more than or equal to 30% and less than or equal to 90%, the fibrous structure content is more than or equal to 10% and less than or equal to 70%, the graphitization degree is more than or equal to 90%, and the first discharge specific capacity of the graphitized anode material is more than or equal to 330mAh/g. The petroleum coke suitable for the energy storage type lithium battery cathode material is prepared by regulating and controlling the composition of the delayed coking raw materials, and has the characteristics of low cost, simple process flow and equipment, mature technology, controllable process conditions, easy 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 negative electrode petroleum coke special for the energy storage type lithium battery is characterized by comprising the following steps of: (1) Mixing vacuum residuum and deoiled asphalt according to a certain proportion to obtain a mixed coking raw material; (2) And (3) carrying out coking reaction on the mixed coking raw material obtained in the step (1) to obtain the petroleum coke.
  2. 2. The method for preparing the negative electrode petroleum coke special for the energy storage type lithium battery as claimed in claim 1, wherein in the step (1), the sulfur content of the vacuum residue is less than or equal to 0.15wt%, the asphaltene content is less than or equal to 0.5wt% and the ash content is less than or equal to 0.01wt%.
  3. 3. The method for preparing the negative electrode petroleum coke special for the energy storage type lithium battery as claimed in claim 1, wherein in the step (1), the sulfur content of the deoiled asphalt is less than or equal to 0.15wt%, the asphaltene content is less than or equal to 0.5wt% and the ash content is less than or equal to 0.01wt%.
  4. 4. The method for preparing the negative electrode petroleum coke special for the energy storage type lithium battery as claimed in claim 1, wherein in the step (1), the mass ratio of the vacuum residue to the deoiled asphalt is 1:9-9:1.
  5. 5. The method for preparing the negative electrode petroleum coke special for the energy storage type lithium battery as claimed in claim 1, wherein in the step (2), the coking reaction temperature is 480-520 ℃, the pressure is 0.01-0.08Mpa, and the coking time is 4-6h.
  6. 6. The special negative electrode petroleum coke for the energy storage type lithium battery is characterized in that the anisotropic content is more than or equal to 95%, the mosaic structure content is more than or equal to 30% and less than or equal to 90% and the fiber structure content is more than or equal to 10% and less than 70% based on the volume fraction of an optical structure.
  7. 7. An energy storage type negative electrode petroleum coke special for lithium batteries, which is characterized by being prepared by the method according to 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 energy storage type lithium battery as well as preparation method and application thereof Technical Field The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to energy storage type special cathode petroleum coke for lithium batteries, and a preparation method and application thereof. Background With the rapid development of society, the energy crisis and the environmental problems caused by the burning of fossil raw materials are increasingly serious, the development of efficient and recyclable energy storage materials is urgent, and the utilization rate of the existing renewable energy sources is improved. The lithium ion battery is one of the most promising energy storage materials, and has the advantages of long cycle life, high energy density, low self-discharge rate, good heat stability, insignificant memory effect and the like, so the lithium ion battery becomes a research hot spot in the field of novel energy sources. The cathode materials which are researched and widely applied to the lithium ion battery mainly comprise a carbon system and a non-carbon system, wherein the carbon system material occupies more than 98% of the cathode market. The carbon system mainly comprises artificial graphite and natural graphite, although the natural graphite has the advantages of low cost and high specific capacity, the natural graphite has poor compatibility with electrolyte, in the charging process, along with the intercalation of solvated lithium ions, a graphite layer is easy to peel off, the cycle life is lower, the safety performance is poor, the performance of the artificial graphite in the cycle performance, the safety performance and the charge-discharge multiplying power is more excellent, the artificial graphite becomes the main stream of the cathode material market, the market share is promoted year by year, and the market share is 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 the residual oil raw material is not pretreated, so that the sulfur content, ash content and metal content of the petroleum coke depend on the properties of the raw material, and the application performance and range of the petroleum coke are different according to different sources of the petroleum coke raw material. Most of petroleum coke is mainly in a mosaic structure, the fiber structure content is low, and the graphitization performance and specific capacity of the petroleum coke are lower than those of needle coke. Although the internal structure of the material is more ordered and graphitized, the capacity of the cathode is high and the cycle performance is better, however, the highly graphitized carbon material has a stable charge-discharge platform although the capacity is high, the cycle performance and the low-temperature performance are poor, because lithium ions form an interlayer compound with graphite sheets when being intercalated between graphite layers, the graphite layers expand, and when lithium ions are separated, the graphite layers recover, and in the repeated expansion and contraction, the graphite layer structure is easy to be damaged, the co-intercalation of solvents is possibly caused, so that the cycle p