What are the components of the lithium battery electrolyte, and whether it is harmful to the human body? Let’s learn about lithium battery electrolyte with Dongguan Yunsheng Electronics:
　　Main components of lithium battery electrolyte
　　1. Ethylene carbonate: Molecular formula: C3H4O3
　　transparent colorless liquid (> 35 ℃), crystalline solid at room temperature. Boiling point: 248°C/760mmHg, 243-244°C/740mmHg; Flash point: 160°C; Density: 1.3218; Refractive index: 1.4158 (50°C); Melting point: 35-38°C; This product is polyacrylonitrile, polyvinyl chloride good solvent. It can be used as spinning liquid in textiles; it can also be directly used as a solvent for removing acid gas and as an additive for concrete; it can be used as a pharmaceutical component and raw material in medicine; it can also be used as a plastic foaming agent and synthetic lubricating oil In the battery industry, it can be used as an excellent solvent for lithium battery electrolyte
　　2. Propylene carbonate molecular formula: C4H6O3
　　colorless and odorless, or light yellow transparent liquid, soluble in water and carbon tetrachloride, and ether, acetone , Benzene, etc. are miscible. It is an excellent polar solvent. This product is mainly used in polymer operation, gas separation process and electrochemistry. In particular, it is used to absorb carbon dioxide in natural gas and synthetic ammonia in petrochemical plants, and can also be used as plasticizer, spinning solvent, olefin and aromatic extractant, etc.
　　Toxicological data: No poisoning was found in animal experiments through oral or skin contact. Rat oral LD50=2,9000 mg/kg.
　　This product should be stored in a cool, ventilated and dry place, away from fire sources, and stored and transported according to the regulations of general low-toxic chemicals.
　　What harm does the lithium battery electrolyte do to the human body
　　? 3. Molecular formula of diethyl carbonate: C5H10O3
　　Colorless liquid with slight odor; vapor pressure 1.33kPa/23.8°C; flash point 25°C (combustible liquid can volatilize into vapor and run into the air. The temperature rises and the volatilization speeds up. When the mixture of volatilized vapor and air is mixed with When the fire source can flash sparks, this short burning process is called flash burning, and the lowest temperature at which flash burning occurs is called flash point. The lower the flash point, the greater the risk of fire.); Melting point -43°C ; Boiling point 125.8°C; Solubility: Insoluble in water, miscible in most organic solvents such as alcohol, ketone, ester; Density: Relative density (water=1) 1.0; Relative density (air=1) 4.07; Stability: Stable ; Hazard mark 7 (flammable liquid); main use: used as a solvent and in organic synthesis
　　①Health hazards
　　Routes of entry: inhalation, ingestion, and percutaneous absorption.
　　Health Hazard: This product is a mild irritant and anesthetic. Inhalation can cause headache, dizziness, weakness, nausea, difficulty breathing, etc. Liquid or high concentration vapor is irritating. Oral irritation of the gastrointestinal tract. Prolonged and repeated skin contact is irritating.
　　②Toxicological information and environmental behavior
　　Toxicity: It is estimated that it can enter the body through the gastrointestinal tract, skin and respiratory tract, showing moderate toxicity. It is more irritating than dimethyl carbonate.
　　Acute toxicity: LD501570mg/kg (rat oral); human inhalation 20mg/L (steam) × 10 minutes, tears and nasal mucosa irritation.
　　Reproductive toxicity: hamster abdominal cavity 11.4mg/kg (pregnant rats), has obvious teratogenic effect.
　　Hazardous characteristics: flammable, there is a danger of burning in case of open flame or high heat. Its vapor is heavier than air, and can spread to a considerable distance at a lower place, and it will ignite back when it encounters an open flame.
　　Combustion (decomposition) products: carbon monoxide, carbon dioxide.
　　③Leakage emergency treatment
　　Quickly evacuate the personnel in the leaked contaminated area to a safe area, and isolate them, strictly restricting access. Cut off the fire source. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and fire protection clothing. Cut off the source of the leak as much as possible. Prevent entry into restricted spaces such as sewers and flood drains. Small spill: Absorb with or other inert material. It can also be brushed with an emulsion made of a non-flammable dispersant, and the lotion is diluted and put into the wastewater system. Large amount of leakage: Construct dikes or dig pits for containment. Cover with foam to reduce vapor hazards. Use an explosion-proof pump to transfer to a tank truck or a special collector, recycle or transport to a waste disposal site for disposal.
　　④ Protective measures
　　Respiratory system protection: When the concentration in the air is high, it is recommended to wear a self-priming filter gas mask (half mask).
　　Eye Protection: Wear safety goggles.
　　Body protection: wear anti-static overalls.
　　Hand Protection: Wear rubber gloves.
　　Others: Smoking is strictly prohibited in the workplace. After work, take a shower and change clothes. Pay attention to personal hygiene.
　　⑤ First aid measures
　　Skin contact: Take off contaminated clothing, wash skin thoroughly with soapy water and water.
　　Eye contact: Lift the eyelids and rinse with running water or saline. Seek medical attention.
　　Inhalation: Quickly leave the scene to fresh air. Keep airway open. If breathing is difficult, give oxygen. If not breathing, give artificial respiration immediately. Seek medical attention.
　　Ingestion: Drink plenty of warm water, induce vomiting, seek medical attention.
　　Fire fighting method: spray water to cool the container, if possible, move the container from the fire site to an open place. Extinguishing media: foam, dry powder, carbon dioxide, sand.
　　4. Dimethyl carbonate: C3H6O3
　　(dimethyl carbonate, DMC), is a non-toxic, environmentally friendly, and widely used chemical raw material. It is an important organic synthesis intermediate, and its molecular structure contains carbonyl, methyl And functional groups such as methoxyl group, have a variety of reactive properties, and have the characteristics of safe use, convenience, less pollution, and easy transportation in production. Because dimethyl carbonate is less toxic, it is a "green" chemical product with development prospects.
　　DMC has excellent solubility, narrow range of melting and boiling points, high surface tension, low viscosity, small electric constant of the medium boundary, high evaporation temperature and fast evaporation speed, so it can be used as a low-toxic solvent for coatings Industrial and pharmaceutical sectors. It can be seen from Table 1 that DMC not only has low toxicity, but also has the characteristics of high flash point, low vapor pressure and high lower explosion limit in air, so it is a green solvent integrating cleanliness and safety.
　　5. Ethyl methyl carbonate
　　molecular weight: 104.1, density 1.00 g/cm3, colorless transparent liquid, boiling point 109°C, melting point -55°C, is a high-tech, high value-added chemical product emerging in recent years, an excellent lithium The solvent for the electrolyte of ion batteries is the latest product extended with the increase in the output of dimethyl carbonate and lithium-ion batteries. Because it has both methyl and ethyl groups, it has the characteristics of dimethyl carbonate and diethyl carbonate. , is also a solvent for special spices and intermediates. Due to the imbalance of the methyl ethyl group, the product is unstable and not suitable for long-term storage.
　　This product should be stored in a cool, ventilated and dry place, and stored and transported according to the regulations of flammable chemicals.
　　6. Lithium hexafluorophosphate
　　White crystal or powder, relative density 1.50. Strong deliquescence; easily soluble in water, also soluble in low-concentration methanol, ethanol, acetone, carbonates and other organic solvents. Decomposes on exposure to air or heating. When exposed to air or heated, lithium hexafluorophosphate decomposes rapidly in the air due to the action of water vapor, releasing PF5 and producing white smoke.
　　7. Phosphorus pentafluoride Phosphorus
　　pentafluoride (chemical formula: PF5) is a phosphorus halide compound, the oxidation number of phosphorus atom is +5, and contains a three-center four-electron bond. Phosphorus pentafluoride is a colorless and malodorous gas at normal temperature and pressure, which is highly irritating to the skin, eyes and mucous membranes. It is a highly active compound that can violently produce toxic and corrosive white fumes of hydrogen fluoride in humid air. Phosphorus pentafluoride is used as a catalyst for the polymerization reaction.
　　National standard number 23022
　　CAS number 7647-19-0
　　Chinese name phosphorus pentafluoride
　　English name phosphorus pentafluoride
　　Alias ​​Phosphorus Fluoride
　　Molecular Formula PF5 Appearance and Properties Colorless, pungent and foul-smelling gas that fumes violently in humid air Molecular
　　weight 126.0 Boiling point-84.6°C
　　Melting point-93.8°C Solubility
　　Density Relative density (water=1) 5.81 ( Gas); relative density (air = 1) 4.3 stability and stability
　　Hazard mark 6 (toxic gas, inorganic poison) is mainly used to generate gas and used as a polymerization catalyst
　　. ① Impact on the environment
　　What harm does the lithium battery electrolyte do to the human body
　　? 1. Health hazards
　　Intrusion route: inhalation.
　　Health Hazard: Produces toxic and corrosive hydrogen fluoride in humid air. This product has a strong stimulating effect on the skin, eyes, and mucous membranes, and can cause respiratory inflammation and pulmonary edema after inhalation.
　　2. Toxicological information and environmental behavior
　　Toxicity: Irritant.
　　Hazardous characteristics: produce white corrosive and irritating fumes of hydrogen fluoride in humid air. It decomposes in water and releases highly toxic and corrosive gases. Decomposes in case of alkali.
　　Combustion (decomposition) products: phosphorus oxide, phosphine, hydrogen fluoride.
　　②. Emergency treatment and disposal methods
　　1. Leakage emergency treatment
　　Quickly evacuate the personnel in the leaking contaminated area to the upwind place, and immediately isolate them. Isolate 300 meters for small leaks and 450 meters for large leaks. Strictly restrict access. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and wear protective clothing. Cut off the source of the leak as much as possible. Reasonable ventilation, accelerate the diffusion. Leakage containers should be properly disposed of, repaired and inspected before reuse.
　　2. Protective measures
　　Respiratory system protection: When you may be exposed to its vapor, you must wear a self-priming filter gas mask (full face mask). Wear an air respirator if necessary.
　　Eye Protection: Protected in respiratory protection.
　　Body protection: wear tape anti-virus clothing.
　　Hand Protection: Wear rubber gloves.
　　Others: Smoking is strictly prohibited in the workplace. Pay attention to personal hygiene.
　　3. First aid measures
　　Skin contact: Take off contaminated clothing and rinse with plenty of running water. Seek medical attention.
　　Eye contact: Lift the eyelids and rinse with running water or saline. Seek medical attention.
　　Inhalation: Quickly leave the scene to fresh air. Keep airway open. If breathing is difficult, give oxygen. If not breathing, give artificial respiration immediately. Seek medical attention.
　　Fire fighting method: Firefighters must wear full-body fireproof and anti-virus clothing. Cut off the air supply. Cool container with water spray, move container from fire to open area if possible. Extinguishing media: dry powder, carbon dioxide.
　　8. Hydrofluoric acid
　　This product is controlled by the public security department according to the "Regulations on the Safety Management of Hazardous Chemicals".
　　Colorless transparent fuming liquid. It is an aqueous solution of hydrogen fluoride gas. Weakly acidic. Has a pungent odor. It reacts with silicon and silicon compounds to form gaseous silicon tetrafluoride, but it does not corrode plastics, paraffin, lead, gold, and platinum. Miscible with water and ethanol. The relative density is 1.298. 38.2% hydrofluoric acid is an azeotropic mixture with an azeotropic point of 112.2°C. Toxic, the minimum lethal dose (rat, intraperitoneal) 25mG/kG. Corrosive, can strongly corrode metal, glass and silicon-containing objects. Vapor inhalation or skin contact can form ulcers which are difficult to heal.
　　①Safety measures
　　Leakage: Quickly evacuate personnel from the leakage-contaminated area to a safe area, isolate them, and strictly restrict access. It is recommended that emergency personnel wear self-contained positive pressure respirators and anti-acid and alkali overalls. Do not come into direct contact with spilled material. Cut off the source of leakage as much as possible to prevent entering restricted spaces such as sewers and flood drains.
　　Small spills: mix with sand, dry lime or soda ash. It can also be washed with a large amount of water, diluted with water and put into the waste water system.
　　Large amount of leakage: Construct dikes or dig pits for containment; use pumps to transfer to tank trucks or special collectors, recycle or transport to waste disposal sites for disposal.
　　②Fire extinguishing method
　　Combustibility: non-combustible
　　Extinguishing media: mist water, foam.
　　Precautions for fire fighting: firefighters must wear oxygen respirators and full-body protective clothing.
　　③Emergency treatment
　　Inhalation: quickly leave the scene to fresh air. Keep airway open. If breathing is difficult, give oxygen. If not breathing, give artificial respiration immediately. Seek medical attention.
　　Ingestion: If swallowed by mistake, rinse mouth with water and drink milk or egg white. Seek medical attention.
　　Skin contact: Take off contaminated clothing immediately, rinse with plenty of running water for at least 15 minutes. Seek medical attention. Or, take off the contaminated clothes immediately, and rinse with diphoterine, and if it is an acid containing fluorine, rinse with hexafluorine. Seek medical attention.
　　Eye contact: Immediately lift the eyelids and rinse thoroughly with plenty of running water or normal saline for at least 15 minutes. Or use a diphenhydramine eyewash (if it is an acid containing fluorine, flush it with hexafluorine) and seek medical attention.
　　④Physical and chemical properties
　　Hydrofluoric acid is an aqueous solution of hydrogen fluoride gas, which is a colorless, transparent to pale yellow smoking liquid. Has a pungent odor.
　　It has weak acidity, but the degree of ionization when it is concentrated is greater than that when it is dilute, which is different from ordinary weak electrolytes. It is highly corrosive and can seriously damage teeth and bones. It is highly corrosive to silicon compounds. It should be stored in airtight plastic bottles.
　　It is obtained by dissolving HF in water. Used for engraving glass, cleaning residual sand on castings, controlling fermentation, electropolishing and cleaning and corroding semiconductor silicon wafers (mixed acid with HNO3). Because the binding ability between hydrogen atoms and fluorine atoms is relatively strong, hydrofluoric acid cannot be completely ionized in water.
　　What are the hazards of lithium-ion electrolytes to the human body?
　　1. Lithium-ion batteries are harmful to the human body. The most dangerous is the electrolyte solution. The electrolyte is an organic volatile liquid, and it is obviously corrosive. Long-term inhalation of volatile gas will damage the respiratory tract.
　　2. Solute: Lithium salts are often used, such as lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF?). Solvent: Since the working voltage of the battery is much higher than the decomposition voltage of water, organic solvents are often used in lithium-ion batteries, such as ether, ethylene carbonate, propylene carbonate, diethyl carbonate, etc.
　　3. Organic solvents often destroy the structure of graphite during charging, causing it to peel off, and form a solid electrolyte interphase (SEI) on its surface, resulting in electrode passivation. Organic solvents also bring safety issues such as flammability and explosion.