Analysis of important types of lithium batteries

Important types of lithium batteries Lithium batteries are divided into liquid lithium batteries (LIB) and polymer lithium batteries (PLB) according to the electrolyte materials used. Lithium battery (lithium 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 refined and cannot be overcharged or over-released during use (it will damage the battery or make it scrap ). Therefore, there are protective components or protective circuits for batteries to prevent damage to expensive batteries. Lithium battery charging requirements are very high. In order to ensure that the terminal 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. Most mobile phones use lithium batteries. Proper use of lithium batteries is very important to extend battery life. According to the requirements of different electronic products, it can be made into flat rectangle, cylinder, rectangle, buckle, etc. Due to changes in materials, the rated voltage of a lithium battery is generally 3.7v, while the positive electrode of lithium iron phosphate (hereinafter referred to as iron phosphate) is 3.2v. When fully charged, the terminal charging voltage is generally 4.2v and 3.65v. The terminal discharge voltage of the lithium battery is 2.75v~3.0v (the operating voltage range or terminal discharge voltage given by the battery manufacturer, each parameter is slightly different, generally 3.0v, 2.5v phosphorus iron). Continuous discharge below 2.5V (phosphor iron 2.0V) is called overdischarge, and overdischarge will cause damage to the battery. Lithium batteries using lithium cobalt oxide as the positive electrode are not suitable for high-current discharge. When the discharge current is too large, the discharge time will be shortened (internal temperature rises, energy loss), which may cause danger. However, the lithium iron phosphate cathode material lithium battery can be charged and discharged with a large current of 20C or more (C is the capacity of the battery, such as Cu003d800mAh, and the charging rate of 1C is 800mA), which is particularly suitable for electric vehicles. Therefore, the maximum discharge current given by the battery manufacturer should be less than the maximum discharge current in use. Lithium batteries have certain requirements for temperature. The factory gives the range of filling temperature, discharge temperature and storage temperature. Overvoltage charging can cause permanent damage to the lithium battery. The charging current of the lithium battery should be in accordance with the battery manufacturer's recommendation, and a limited current circuit should be used to prevent overcurrent (overheating). The commonly used charging rate is 0.25C~1C. When charging with high current, the temperature of the battery is usually tested to prevent the battery from overheating, which can damage the battery or cause an explosion. Lithium battery charging is divided into two stages: constant current charging, which changes to constant voltage charging in a manner close to the terminal voltage. Taking 800mAh battery as an example, the terminal charging voltage is 4.2v. In the constant current charging of the 800 mA battery (charging rate 1c), the battery voltage starts with a larger ramp boost. When the battery voltage is close to 4.2V to 4.2V, the constant voltage charging, the current gradually decreases, and the voltage changes little. The current is 1/10-50c (GeChang has different values u200bu200band does not affect the use), which is close to full and may terminate the charging (some chargers start the timer 1/10c after pressing the time, and the charging ends after pressing the time). 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: How to prevent lithium battery from bursting?