Lithium battery charging, safety, security, or security

Today, more and more of our electronic products around, mobile phones, hand rings, Bluetooth headsets, smart watches, etc., for these electronic products have become a compulsory daily recharge for everyone. Now the electronic products are used as a power supply of lithium batteries, lithium batteries over the years on the news of the explosion is the fire, the safety of lithium battery use is becoming increasingly important.

Regardless of the size or shape of lithium batteries have any difference, its internal structure is basically by the cathode, anode, electrolyte and positive and negative membrane between the membrane composition. So what are the causes of lithium battery explosion caused it?

First of all, the quality of the battery itself is very important reason. Electrolyte impurities, the process failed, the safety design of the battery itself is not in place, the diaphragm itself defects, structural design is unreasonable, etc., may cause lithium battery in the course of the explosion caused by overheating.

Second, the battery has long been washed off. Lithium-ion battery charging voltage is longer than 4.3V, long-term high-current charge, or long-term over-discharge to very low voltage, may cause damage to the battery internal, explosion hazard. These hazards may be in some special circumstances, instantaneous discharge caused by high current, causing an explosion.

Finally, is caused by short-circuit the battery. Phone long-term at high temperature, or friction impact and other causes of positive and negative through the diaphragm caused by short circuit. Short-circuit the battery will cause a sharp increase in instantaneous current, temperature, causing an explosion.

From the above reasons can be seen, to avoid the use of lithium batteries in the process of problems, in addition to the quality of the battery itself, high current, high voltage, and high temperature is the point we need special attention. Therefore, in the design of lithium battery applications need to consider the following points:

1) Note the lithium battery charge and discharge current. Lithium battery charge and discharge current is generally expressed by the discharge C rate. C rate = charge and discharge current / rated capacity. General lithium battery in use, the charge and discharge current in the 1C or so, the maximum try not to exceed 2C (here refers to the general lithium batteries, power batteries, high voltage batteries, etc.).

2) Avoid overshoot. In addition to charging voltage not more than 4.3V, but also pay attention to high-current charging time not too long. This part of the control depends on the charge management circuit to complete.

3) attention to circuit thermal design. In the lithium battery around to retain the cooling channel, the charging circuit part of the circuit wiring should be as wide as possible, to maintain good heat dissipation.

4) battery external structure design. Structural design should consider the fixation of lithium batteries, as well as the reinforcement around the battery to prevent the impact, drop and other causes of battery deformation.

5) Battery external components selection. Particular attention to the choice of filter capacitor, select the appropriate filter capacitor can reduce the power supply ripple effect on the battery.