Principle and charger of the hottest lithium ion b

Principle and charger of lithium ion battery

lithium ion battery is a substitute product of metal lithium battery that appeared a few years ago. Its anode adopts a carbon pole that can absorb lithium ions. When discharging, lithium turns into lithium ions, separates from the battery anode and reaches the cathode of lithium ion battery. Lithium ions move between the anode and cathode, and the electrode itself does not change. This is the essential difference between lithium ion battery and metal lithium battery. The anode of lithium-ion battery is graphite crystal, and the cathode is usually dioxygen. China is still in the stage of industrialization, informatization, urbanization, marketization and internationalization. When charging, lithium atoms in the cathode ionize into lithium ions and electrons, and lithium will become the fastest-growing plastic printing equipment in the future. It will move to the anode and synthesize lithium atoms electronically. During discharge, lithium atoms are ionized from the anode surface of graphite crystal into lithium ions and electrons, and lithium atoms are synthesized at the cathode. Therefore, in this battery, lithium always appears in the form of lithium ion, not in the form of metal lithium, so this kind of battery is called lithium ion battery

I. charge and discharge characteristics of lithium ion battery

500mah AA type lithium ion battery charge and discharge characteristic curve. The charging voltage of a single lithium-ion battery should be kept at 4.1V + 50mV, and the charging current supplied by the battery manufacturer to apple is usually limited to below 1C (500mA), otherwise it will cause permanent damage to the lithium-ion battery. Lithium ion batteries usually adopt constant current/constant voltage charging mode, that is, 1c constant current is used for charging first, and the battery voltage keeps rising. When it rises to 4.1V, the charger should immediately switch to constant voltage mode (4.1V + 50mV), and the charging current gradually decreases. When the battery is fully charged, the current drops to trickle charging current. With this method, the battery can be sufficient (500mah) in about two hours. The discharge current of lithium-ion battery should not exceed 3C (1.5A), and the voltage of single battery should not be less than 2. It is around the needs and expectations of enterprises and the public 2V, otherwise it will cause damage. With a discharge current of 0.2C, the rated battery capacity (500mah) can be discharged when the battery voltage drops to 2.7V. With a discharge current of 1C, the battery can discharge 90% of the battery capacity. In addition, the ambient temperature will also affect the battery discharge capacity. Therefore, the temperature of lithium-ion battery discharge is specified as -20 ℃ ~ ＋ 60 ℃. One feature of lithium-ion battery is that it is easy to display the remaining power, because the working voltage of lithium-ion battery gradually decreases with time. The starting voltage of lithium-ion battery discharge is 4.1V (4.2V), and the ending voltage of discharge is 2.5V

II. Advantages and disadvantages of lithium ion battery

advantages: 1 High working voltage; 2. Small size, light weight and high energy; 3. Long service life; 4. Safe and fast charging; 5. Wide allowable temperature range; 6. Small discharge current, no memory effect and no environmental pollution

disadvantages: 1 No interchangeability with dry battery; 2. Unable to charge quickly; 3. High internal impedance; 4. The working voltage changes greatly; 5. The discharge rate is large and the capacity decreases rapidly, so it is impossible to discharge with high current

III. lithium ion battery charger

next, a new type of lithium ion battery charger module ps1719 is introduced, which uses constant current/constant voltage mode to control lithium ion battery charging. It is convenient to adjust constant current and constant voltage. The charging current is reduced to 15% of the maximum current (constant current) as the full charge criterion, and the charging is terminated. In addition, there are charging display and full charge display functions. The working voltage of ps1719 module is 9V, with internal structure. (end)