How do we use lithium batteries?

With the rapid development of portable products, the consumption of different batteries has increased significantly, and many new types of batteries have been developed. In addition to the well-known high-performance alkaline batteries, rechargeable nickel-cadmium batteries, and nickel-metal hydride batteries, lithium batteries have also been developed in recent years. Lithium batteries have a spiral wound structure and use a very fine and highly permeable polyethylene foil separator to separate the positive and negative electrodes.

What factors affect the life of lithium batteries?

If a lithium battery is fully charged for a long time, what will happen to the battery?

How to ensure the safety of lithium batteries?

What factors affect the life of lithium batteries?

1. Overload, deep load, large loading and unloading current

Avoid overloading lithium batteries. Any form of lithium battery overload can seriously damage the battery power and even explode.

Avoid deep charging below 2V or 2.5V, as this can quickly and permanently damage the lithium battery. There may be internal metallization, which can cause a short circuit, rendering the battery unusable or uncertain.

Most lithium batteries have an electronic circuit in the battery pack. The electronic circuits disconnect the battery if the battery voltage is below 2.5V, exceeds 4.3V during charging or discharging, or if the battery current exceeds a predetermined threshold.

Avoid large load and discharge currents, as large currents can overload the battery.

2. The environment is too hot or too cold

Temperature also has a great impact on the life of lithium batteries. Environments below freezing point can cause lithium batteries to burn when electronics are turned on, and overheated environments can reduce battery capacity. So, if the laptop is used for a longer period of time without removing the battery from the external power source, the battery will be paused for longer due to the laptop's high heat output and will be damaged very quickly.

If a lithium battery is fully charged for a long time, what will happen to the battery?

Both too high and too low performance conditions can adversely affect the life of lithium batteries. The number of rechargeable cycles shown on most sold devices or batteries is based on 80% discharge as a comparative test. Experiments have shown that for some laptop lithium batteries, the battery voltage often exceeds the standard voltage by 0.1 volts, that is, from 4.1 volts to 4.2 volts, the battery life is halved, if 0.1 volts are increased, the life is shortened to 1/3 of the original; Being in a state of little or no charge for a long time means that the battery's internal resistance to the movement of electrons increases, which reduces the battery capacity. Lithium batteries are best in moderate performance, in which case the battery life is the longest.

How to ensure the safety of lithium batteries?

In order to avoid low battery or overload due to improper use, a triple protection mechanism is provided in a single lithium battery cell. One is the use of switching elements. If the temperature in the battery increases, the resistance also increases. If the temperature is too high, the power supply will stop automatically; The second is to choose the right separator material. When the temperature rises to a certain value, the microprocessor on the separator will automatically dissolve, making it impossible for lithium ions to pass through, and the internal reaction of the lithium battery stops; The third is to adjust the safety valve. When the internal pressure of the lithium battery increases to a certain value, the safety valve will automatically open to ensure the safety of the battery.

Sometimes, although the lithium battery itself has safety control, due to some reason the control fails, the safety valve is missing or the safety valve releases gas too late, the internal pressure of the lithium battery will increase dramatically, and then it will cause an explosion.

Under normal conditions, the total energy stored by lithium batteries is inversely proportional to their safety. As the capacity of the battery increases, the volume of the battery increases, its heat output deteriorates, and the likelihood of accidents increases dramatically. As far as mobile phone lithium batteries are concerned, the basic requirement is that the probability of safety accidents should be less than 1 million to 1 million, which is also the lowest probability acceptable to the public.

For large-capacity lithium batteries used in automobiles, especially high-capacity lithium batteries, the use of forced heat dissipation is particularly important.