Shenzhen Sendi Biotechnology Co., Ltd.

Chinese name: Graphite fluoride

Chinese Synonyms: fluorocarbon compounds; fluorinated graphite; 30% fluorinated graphite; fluorinated graphite 1KG

English name: FLUOROGRAPHITE (TM)

GRAPHITE, FLUORINATED, POLYMER, LOW FLUO RINE; GRAPHITE, FLUORINATED, POLYMER, HIGH FLUORINE; FLUOROGRAPHITE POLYMER: X = 0.9 , 58% F; FLUOROGRAPHITE POLYMER: X = 1, 61% F; X = 1, 61% F

CAS #: 11113-63-6; 51311-17-2

Molecular formula: C.xF2

Chinese name: carbon fluoride

Chinese Synonyms: carbon fluoride; Graphite fluorinated polymer; Graphite fluoride polymer

Molecular weight: 0

EINECS number: 234-345-5

Overview Graphite fluoride is one of the hot research topics in the world of high-tech, high-performance and high-efficiency novel carbon / graphite materials. Its excellent performance and unique quality make it a wonderful workable material family.

Color of graphite fluoride is a gray to white inorganic polymer powder, many scholars believe that fluoride fluoride and carbon fluoride ratio varies with the reaction conditions vary between 0.5 to 1.2, the product color from the corresponding gray To white.

Synthetic process 1, Direct synthesis process. Graphite and gaseous fluorine in 350 ~ 600 in the reactor heating synthesis, the earliest use of synthetic methods. Equipment for vertical vibration reactor or fluoridizer, can automatically control the heating temperature, fluorine and inert gas into the.

2, the catalyst synthesis process. In the graphite and fluorine reaction system by adding trace metal fluoride (LiF,

MgF2, AlF3 and CuF2) as a catalyst, the synthesis can be carried out below 300 . Due to the addition of trace metal fluoride, the properties of fluorinated graphite are changed, and the conductivity is increased by one order of magnitude. Requires graphite and fluorine purity of 99.4% are above, the catalyst purity is greater than 98%. The equipment used is the same as the direct synthesis method.

3, solid fluoride synthesis process. The above-mentioned two methods are extremely toxic and corrosive to fluorine, and the reaction requires high temperature. The solid synthesis process is a process of mixing graphite with a fluorine-containing solid polymer such as a polymer made of tetrafluoroethylene, hexafluoropropylene, polyvinylacetate fluorite, and vinyl fluorite in the presence of helium, neon, argon, nitrogen, etc. Under inert atmosphere, heated to 320 ~ 600 , in the tube furnace tube made of graphite fluoride. The principle of the process shown in Figure 10-20. Graphite and water suspension and polytetrafluoroethylene according to the ratio of 1:10 after mixing, filtered and dried into a tube furnace heating, after 30min to 1h removed and cooled. 4, electrolytic synthesis process. Electrolysis method, the graphite in anhydrous hydrofluoric acid electrolysis, generate new graphite fluoride. That is, in the electric field, between the anode and the cathode, graphite and hydrofluoric acid are electrolytically recycled to form graphite fluoride.

Electrolytic device made of nickel plate anode and cathode, circulation and circulation pump, made of polytetrafluoroethylene porous separator, exhaust pipe, DC power supply and other components. Graphite and hydrofluoric acid suspension are contained in the electrolysis zone of the two electrodes and circulate in a closed circuit under the action of a circulating pump. In the suspension, the graphite solid content was 10%, the hydrofluoric acid contained 1% water, the temperature in the argon atmosphere electrolytic tank was -20 C, the applied voltage was 8V and the average current density was 5A / cm2. The distance between the two plates is about 5 mm. After placing the separator, the anode and the cathode are separated from the separator by 2 mm and 3 mm, respectively, forming a closed-circuit circulation between the separator and the separator. After the reaction is completed, the graphite-containing hydrofluoric acid suspension is discharged and the graphite fluoride is separated by filtration, the liquid is returned to reuse, and the new suspension to be reacted is added while discharging.

Crystal structure Japan, Watanabe Shin-chan proposed that graphite fluoride only (CF) n and (C2F) n two kinds of chemical analysis that the fluorocarbon ratio of 0.58 ~ 1.2 result is due to different reaction conditions in the product (CF) n And (C2F) n ratio, and the edge of the carbon layer adsorbed a certain amount of = C and -CF3 due to graphite fluoride hexagonal layered structure. Graphite fluoride is an intermetallic compound of fluorine element and graphite. Compared with graphite, its electronic structure and lattice constant have changed. The crystal structure of fluorinated graphite is shown in the following figure. CC bond in fluorinated graphite is expanded from 0.142nm of graphite CC bond length to 0.152nm, and at the same time, the interlayer distance of fluorinated graphite is changed from that of graphite 0.336 nm to 0.708 nm, which makes it a typical molecular crystal linked by van der Waals forces. Due to the uncertainty of the van der Waals radius and the degree of fluorination, the fine pitch of fluorinated graphite is reported in the literature as 0.6-0.9 nm.

Nature 1, good chemical resistance. Chemical resistance at room temperature is better than polytetrafluoroethylene. Of concentrated sulfuric acid and concentrated nitric acid is also very stable, insoluble in all kinds of organic solvents. However, hot concentrated sulfuric acid, hot alkali has some invasion of it, and at high temperatures and alkali metal, alkali halogen compounds react to form a fluoride base and amorphous carbon.

2, good thermal stability (above 500 only a small amount of weight loss).

3, good lubricating performance, is the grease and solid lubricant (molybdenum disulfide, graphite, etc.) in the friction coefficient

The lowest, in 27 ~ 344 , the friction coefficient is only 0.10 ~ 0.13.

4, good electrical insulation, (CF) n resistivity of 3 103 / cm or more.

5, Mohs hardness of 1.0 to 2.0

6, the particle size distribution is very wide, from 1m to more than a few millimeters.

Application 1, as a solid lubricant. The graphite fluoride layer has extremely low binding energy of 8.4 kJ / mol, excellent lubricity, and is not affected by the atmosphere such as oxidation, reduction and vacuum, and can be used in a wide range of temperatures from low temperature to high temperature. The friction coefficient is less than the friction coefficient of butter, is an excellent lubricating material.

2, as the battery active material. Fluorinated graphite battery as a battery active material made of high voltage battery (nominal voltage of 3V), high energy density, excellent storage and a wide temperature range.

3, for low surface energy material applications. In the plywood manufacturing process, coated with graphite fluoride to prevent adhesive adhesion, extend the clean processing cycle.

4, a small amount of fluorinated graphite to prevent liquid penetration in the porous material. Electroplating metal, graphite fluoride co-precipitation electrode surface does not produce material adhesion, and this electrode in the electrolysis of water and non-aqueous solvent mixture, only non-aqueous electrolysis.

Use as a high-energy battery cathode material and solid lubricating materials