Lithium battery pack for electric vehicles, introduction to lithium battery knowledge

The general trend for lithium battery electric vehicles to replace fuel vehicles in the future has been determined. The lithium batteries used in electric vehicles are generally lithium ion batteries and lithium iron phosphate batteries. Compared with lead-acid batteries, lithium batteries with higher energy density can not only get more Long cruising range, and can make the body lighter. Next, the author will briefly describe the relevant knowledge of lithium batteries in electric vehicles; the characteristics of lithium batteries used in electric vehicles; advantages 1. The energy is relatively high. It has a high storage energy density, which has reached 460-600Wh/kg, which is about 6-7 times that of lead-acid batteries; 2. 2. Long service life, service life can reach more than 6 years, 1C (100% DOD) charge and discharge of the battery with lithium iron phosphate as the positive electrode, there is a record that can be used 10,000 times; 3. The rated voltage is high (the single working voltage is 3.7V or 3.2V), which is approximately equal to the series voltage of 3 nickel-cadmium or nickel-metal hydride rechargeable batteries, which is convenient to form a battery power pack; lithium batteries can pass a new type of lithium battery voltage regulator The technology adjusts the voltage to 3.0V to suit the use of small appliances. 4. It has high power endurance, and the lithium iron phosphate lithium ion battery used in electric vehicles can reach 15-30C charge and discharge capacity, which is convenient for high-intensity start-up acceleration; 5. The self-discharge rate is very low, which is one of the most prominent advantages of the battery. Generally, it can be less than 1%/month, which is less than 1/20 of the nickel-hydrogen battery; 6. Light weight, the weight is about 1/6-1/5 of the lead-acid product under the same volume; 7. High and low temperature adaptability, it can be used in the environment of -20℃--60℃, after the process treatment, it can be used in the environment of -45℃; 8. Green and environmental protection, regardless of production, use or scrap, it does not contain or produce any toxic and harmful heavy metal elements and substances such as lead, mercury, and cadmium. 9. Production basically does not consume water, which is very beneficial to my country, which is short of water. Specific energy refers to the energy per unit weight or unit volume. Specific energy is expressed in Wh/kg or Wh/L. Wh is the unit of energy, W is watt, h is hour; kg is kilogram (weight unit), L is liter (volume unit). Disadvantages 1. Lithium primary batteries have poor safety, and there is a danger of explosion. 2. Lithium cobalt oxide lithium-ion batteries cannot be discharged at high currents, are expensive, and have poor safety. 3. Lithium-ion batteries need to protect the circuit to prevent the battery from being overcharged and over-discharged. 4. The production requirements are high and the cost is high. 5. The use conditions are limited, and the use of high and low temperature is dangerous. Lithium battery knowledge introduction-battery characteristics; the weight of a high-energy density lithium-ion battery is half of the nickel-cadmium or nickel-hydrogen battery of the same capacity, and the volume is 20-30% of the nickel-cadmium and 35-50% of the nickel-hydrogen battery. High voltage A single lithium-ion battery has a working voltage of 3.7V (average value), which is equivalent to three nickel-cadmium or nickel-hydrogen batteries connected in series. Pollution-free lithium-ion batteries do not contain harmful metal substances such as cadmium, lead, and mercury. Metal-free lithium lithium-ion batteries do not contain metal lithium, so they are not subject to restrictions on the prohibition of carrying lithium batteries on passenger planes in aircraft transportation. High cycle life Under normal conditions, the charge and discharge cycles of lithium-ion batteries can exceed 500 times, and lithium iron phosphate (hereinafter referred to as ferrophosphorus) can reach 2000 times. Memory-free memory effect refers to the phenomenon that the capacity of the nickel-cadmium battery decreases during the charging and discharging cycle. Lithium-ion batteries do not have this effect. Fast charging uses a constant current and constant voltage charger with a rated voltage of 4.2V, which can fully charge the lithium-ion battery in 1.5-2.5 hours; while the newly developed lithium iron phosphate battery can be fully charged in 35 minutes. Electric vehicles provide users with convenient travel, and electric vehicles using lithium batteries can run farther. At present, electric vehicles with a range of hundreds of kilometers have appeared. It is believed that this value will continue to grow with the continuous improvement of lithium battery technology in the future. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Lithium battery discharge method and charging method