High performance lithium ionic cell cathode material and method for producing the same

A technology for lithium-ion batteries and negative electrode materials, applied in electrode manufacturing, battery electrodes, circuits, etc., can solve uneven coating, low tap density, affecting cycle efficiency of resin-coated graphite materials, and cycle stability Graphite electrode compression To improve the overall electrical performance and improve the uniformity

Inactive Publication Date: 2008-04-16
CHINA ELECTRONIC TECH GRP CORP NO 18 RES INST
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AI-Extracted Technical Summary

Problems solved by technology

If these materials are not processed, they have low tap density and large specific surface area. When they are made into negative electrode slurry with adhesives, conductive agents and solvents, their fluidity is poor, and their adhesion to copper foil current collectors is also poor.
In addition, when the battery is formed, there is a large difference in reactivity between the edge and bottom of the graphite crystallite and the electrolyte, and the surface cannot form a uniform, dense and thin passivation film. Therefore, these materials cannot be used directly, and need to be pulverized, purified, manufactured It has good comprehensive electrical properties only after particle, stabilization and surface modification
Pulverization, grading and processing graphite particles into spherical shapes have indeed significantly improved the tap density and rate characteristics of graphite, but the charge-discharge efficiency and cycle stability are poor
[0004] Known people carry out the method for surface treatment of graphite at present: as U.S. Patent US Patent, No.6,096,454 and US Patent, No.3,011,920 adopt lithium salt or alkali passivation graphite surface, make graphite surface generate one deck passivation film, this The method is simple to operate and easy to realize large-scale industrial production. The key to realize this method is to increase the wettability or hydrophilicity of the graphite surface. Difficult to achieve the desired effect; US Patent No.5344726 and US Patent No.6432583B 1 Chemical vapor deposition is used to thermally decompose toluene, propylene, etc. in a fluidized bed formed by carrier gas such as nitrogen or argon, and deposit a layer of carbon material with high crystallinity on the surface of graphite. This method has relatively high requirements for equipment. High, and the technology is difficult to master; U.S. Patent No.5,401,598 discloses that a layer of organic polymer is coated on the graphite surface, and then pyrolyzed at a high temperature under an inert atmosphere, so that the generated hard carbon is coated on the graphite surface, thereby improving the graphite surface. cycle stability, this method h...
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Abstract

The present invention belongs to a high-performance lithium-ion battery cathode material and a method for preparing the same; solvent, resin and asphalt are added to a container and graphite grains are then added by stirring; the solvent is steamed out through heating up and decompression to form the graphite coated with resin and asphalt which is then put to an inert atmosphere charring furnace for heat treatment; the graphite is cooled to the cycle process less than 100 DEG C after 1 hour to 10 hours; material is taken out, smashed and sieved to grains with grain diameter less than 5 um; after the accumulated volume fraction of grains is less than 10 percent, the high-performance lithium-ion battery cathode material is achieved. As the graphite grains are covered with mixed high molecular polymer made of resin and asphalt, not only the advantages of the resin and asphalt are used, but also the resin has the characteristics of solving asphalt and having condensation polymerization with asphalt, thereby the uniformity, operability and electrical property of covering the graphite grains are improved. By adjusting the proportion of asphalt to resin and controlling the specific surface area of covering graphite grains, the invention has different cycle stability and multiplying power property.

Application Domain

Technology Topic

Examples

  • Experimental program(4)
  • Comparison scheme(4)

Example Embodiment

[0020] Example 1 In a 2L container, add 0.2L xylene, slowly add 6.8g F01-1 novolac resin and 3.4g modified asphalt containing 50% of solvent and solid content respectively under stirring, after the asphalt is basically completely dissolved , slowly add 0.13kg of spherical natural graphite under stirring, heat up to 120°C for 1 hour after adding graphite, keep stirring for 2 hours, evaporate the solvent under reduced pressure, and condense and recover the solvent with tap water. Under the protection of nitrogen, the spherical natural graphite coated with pitch and novolac resin was put into the carbonization furnace and raised to 700°C at a rate of 0.5°C/min, maintained for 2 hours, cooled to below 100°C and taken out. After crushing, sieving and grading, heat up to 1100°C at 0.8°C/min under the protection of nitrogen, keep warm for 2 hours, turn off the power, and take out the material after the temperature drops below 100°C, after crushing, sieving and grading It is the anode material of lithium ion battery.

Example Embodiment

[0021]Example 2 In a 2L container, add 0.2L xylene, slowly add 4.8g F01-1 novolak resin and 0.55g 213# resin without solvent and 3.4g modified asphalt under stirring, after the asphalt is basically completely dissolved , slowly add 0.13kg of spherical natural graphite under stirring, heat up to 120°C for 1 hour after adding graphite, keep stirring for 2 hours, evaporate the solvent under reduced pressure, and condense and recover the solvent with tap water. Under the protection of nitrogen, the spherical natural graphite coated with pitch and novolac resin was put into the carbonization furnace and raised to 700°C at a rate of 0.5°C/min, maintained for 2 hours, cooled to below 100°C and taken out. After crushing, sieving and grading, heat up to 1100°C at 0.8°C/min under the protection of nitrogen, keep warm for 2 hours, turn off the power, and take out the material after the temperature drops below 100°C, after crushing, sieving and grading It is the anode material of lithium ion battery.

Example Embodiment

[0022] Example 3 In a 2L container, add 0.2L xylene, slowly add 8.2g furfural and 3.4g modified asphalt under stirring, after the asphalt is basically completely dissolved, add 0.82g p-toluenesulfonic acid, keep stirring, slowly Add 0.13 kg of spherical natural graphite. After adding graphite for 1 hour, heat up to 120° C. and keep stirring for 2 hours. The solvent is distilled off under reduced pressure, and the solvent is recovered by condensation with tap water. Under the protection of nitrogen, put the spherical natural graphite coated with pitch and furfural resin into the carbonization furnace to raise the temperature to 700°C at a rate of 0.5°C/min, and maintain it for 2 hours, then cool it down to below 100°C and take it out. After crushing, sieving and grading, heat up to 1100°C at 0.8°C/min under the protection of nitrogen, keep warm for 2 hours, turn off the power, and take out the material after the temperature drops below 100°C, after crushing, sieving and grading It is the anode material of lithium ion battery.
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Description & Claims & Application Information

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the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
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