Lithium battery pack parts and important types

Steel shell/aluminum shell/cylindrical/soft packaging series: (1) The positive active material is generally lithium manganese oxide or lithium cobalt oxide, and lithium nickel cobalt manganese oxide materials. Electric bicycles generally use lithium nickel cobalt manganese oxide (commonly known as ternary) or Ternary + a small amount of lithium manganate, pure lithium manganate and lithium iron phosphate are gradually faded out due to large volume, poor performance or high cost. The conductive current collector uses electrolytic aluminum foil with a thickness of 10-20 microns. (2) Diaphragm A specially formed polymer film with a microporous structure that allows lithium ions to pass freely, but electrons cannot pass. (3) The negative electrode active material is graphite, or carbon with a similar graphite structure, and the electrolytic copper foil with a thickness of 7-15 microns is used as the conductive current collector. (4) Carbonate-based solvents of lithium hexafluorophosphate are dissolved in organic electrolytes, and gel-like electrolytes are used for polymers. (5) The battery shell is divided into steel shell (square type is rarely used), aluminum shell, nickel-plated iron shell (for cylindrical batteries), aluminum plastic film (soft packaging), etc., as well as battery caps, which are also the positive and negative electrodes of the battery. Lead out. According to the different electrolyte materials used in lithium batteries, lithium batteries are divided into liquid lithium batteries (LiquifiedLithium-IonBattery, referred to as LIB) and polymer lithium batteries (PolymerLithium-IonBattery, referred to as PLB). Lithium battery (Li-ion) rechargeable lithium battery is currently the most widely used battery in modern digital products such as mobile phones and notebook computers, but it is more delicate and should not be overcharged or overdischarged during use (it will damage the battery or make it) scrapped). Therefore, there are protective components or protective circuits on the battery to guard against expensive battery damage. Lithium battery charging requirements are very high. To ensure that the termination voltage accuracy is within ±1%, major semiconductor device manufacturers have developed a variety of lithium battery charging ICs to ensure safe, reliable, and fast charging. Lithium batteries with lithium cobalt oxide type materials as the positive electrode are not suitable for high current discharge. Excessive current discharge will reduce the discharge time (higher temperature inside and loss of energy) and may be dangerous; but lithium iron phosphate positive electrode The material lithium battery can be charged and discharged with a large current of 20C or even greater (C is the capacity of the battery, such as Cu003d800mAh, 1C charging rate, that is, the charging current is 800mA), which is especially suitable for electric vehicles. Therefore, the battery processing plant gives the maximum discharge current, which should be less than the maximum discharge current during use. Lithium batteries have certain requirements for temperature. The factory provides the charging temperature range, discharging temperature range and storage temperature range. Overvoltage charging will cause permanent damage to the lithium battery. The charging current of the lithium battery should be based on the proposal of the battery manufacturer, and a current-limiting circuit should be required to avoid overcurrent (overheating). The commonly used charging rate is 0.25C～1C. It is often necessary to test the battery temperature during high-current charging to guard against damage to the battery or explosion due to overheating. Lithium battery charging is divided into two stages: first, constant current charging, and changing to constant voltage charging when it is close to the termination voltage. For example, a battery with a capacity of 800 mAh, whose final charging voltage is 4.2V. The battery is charged with a constant current of 800mA (charging rate of 1C). At the beginning, the battery voltage is boosted with a larger slope. When the battery voltage is close to 4.2V, it is changed to 4.2V constant voltage charging. The current gradually drops and the voltage changes little. When the charging current drops to 1/10-50C (various factory settings, it does not affect the use), it is considered to be close to overflowing, and the charging can be terminated (some chargers will start the timer after 1/10C, u200bu200band the time will pass. After the end of charging). Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: How to weld 18650 lithium battery?