Do you know how Li-ion batteries classified?
According to the difference of electrolyte materials, Li-ion battery is divided into Liquified Lithium-Ion Battery (LIB) and Polymer lithium-ion battery (PLB).
Rechargeable Li-ion battery is the most widely used batteries in modern digital products, such as mobile phone, notebook computer and so on. But it's relatively fragile, in using, do not overcharge or discharge (will damage the battery or the scrap). Therefore, there are protective components or protective circuits on the battery to prevent expensive battery damage.Lithium ion battery charging is very easy demanding. To ensure that the termination voltage accuracy is within 1%, the major semiconductor device factories have developed various IC for lithium ion battery charging to ensure safe, reliable and fast charging.
A cell phone is basically using a lithium ion battery.It is very important to use lithium ion batteries correctly to prolong its life.It can be made into flat rectangular, cylindrical, rectangular and button based on the requirements of different electronic products, and there are battery pack consisting of several batteries connected in series. The rated voltage of the lithium ion battery is generally 3.7V, and the cathode of the lithium iron phosphate is 3.2V because of the change of the material.When full charged, the termination of the charging voltage is 4.2V while ironic phosphate 3.65V. The termination of the discharge voltage of lithium ion battery for 2.75V ~ 3.0V (battery factories' working voltage range or a termination of the discharge voltage of each parameter is slightly different, generally 3.0V and ironic phosphate 2.5V).Less than 2.5V (iron 2.0V) continue to discharge called over discharge and it will damage the battery.
Li-ion batteries with lithium cobalt type materials as positive poles are not suitable for large current discharge,excessive current discharge will reduce the discharge time (the internal will produce higher temperature and loss energy), and may be dangerous. But lithium iron phosphate cathode material li-ion battery can be charged at 20C or even larger (C is the battery capacity, such as C=800mAh, 1C charging rate, charging current 800mA), especially for electric vehicle.Therefore, the battery production plant gives the maximum discharge current, which should be less than the maximum discharge current in use. Li ion battery has certain requirements for temperature. The factory has given the temperature range of charging, the discharge and the storage. The overvoltage charging will cause permanent damage to the li-ion battery.The charge current of a li-ion battery should be based on the proposal of the battery manufacturer and requires a limited current circuit to avoid overheating. The commonly used charging ratio is 0.25C to 1C. The temperature of the battery is often detected in large current charging to prevent overheating from damage to the battery or to produce an explosion.
The li-ion battery charge is divided into two stages: The first constant current charging is changed to constant voltage charging when the end voltage is close to the end voltage. For example, a battery with 800mAh capacity, whose termination charge voltage is 4.2V. Battery with 800mA (charging rate 1C) constant current charging, the battery voltage to boost at the start of slope is larger, when the battery voltage is close to 4.2V, then change to 4.2V constant voltage charging, voltage current gradually drop, little change to the charging current is reduced to 1/10-50C (the factory set value, does not affect the use). That is close to full, can stop charging (some charger to 1/10C after the start timer, after a certain time after the end of charging).