Take you a quick understanding of lithium-ion batteries in one minute

First of all, we must understand the charging and discharging principle of lithium-ion batteries. The battery has two poles: the positive electrode is a lithium compound, and the negative electrode is graphite.

Both charging and discharging are the mutual conversion of electrical energy and chemical energy. During the movement of positive and negative electrodes, lithium ions are also changing into different compounds.

We can think of lithium ions as a small car with electric charge: when charging, the electric field makes the car drive to the negative electrode to store a certain amount of energy (lithium ions are inserted into the micropores of the graphite carbon layer of the negative electrode); when discharging, These charged lithium-ion carts ran to the positive electrode due to a chemical reaction (the deintercalation of lithium ions makes the positive electrode in a lithium-rich state). In this process, a current supply is formed.

Take you a quick understanding of lithium-ion batteries in one minute

In an ideal state, as long as the chemical structure of the positive and negative materials basically does not change, the reversibility of the battery charge and discharge is very good, and the lithium ion battery can guarantee a long time cycle.

Fast charging is mainly to ensure that lithium ions are quickly inserted from the positive electrode and quickly inserted into the negative electrode, without causing the deposition of lithium ions.

However, when the current increases, the semi-permeable membrane (SEI membrane) on the surface of the negative electrode (graphite) of the electrode will rupture to a certain extent, causing the electrode material and the electrolyte to react with each other. In addition, the increase in temperature will also cause secondary effects inside the battery. The reaction destroys the chemical substances on the battery, resulting in a decrease in reversibility (the lithium-ion car cannot be driven back and forth) and the battery capacity will continue to decrease.

Lithium battery charging is divided into three parts: constant current pre-charge (CCPre-charge), high current constant current charge (CC Fast Charge) and constant voltage charge (CV).

The voltage drops after the mobile phone’s power is exhausted. When it is below a certain value, the charger will use a relatively low current to precharge the lithium battery. After a period of time, when the voltage of the lithium battery is higher than the predetermined value, it enters the second stage of high-current constant-current charging. At this time, appropriately increasing the current can speed up the charging.

If you are using a non-fast-charge mobile phone, the fast-charge charging head will not output high voltage and burn your mobile phone. For example, when you use the iPad charging head to charge the iPhone, the iPad will automatically recognize it and input 1A current instead of the original 2A.

Will fast charging affect battery life?

The answer is yes.

Even though the batteries equipped on some fast-charging mobile phones have improved cell materials and design, which can realize the rapid insertion and insertion of lithium ions in the battery, the large voltage and current still cause the battery to lose.

But if you are used to changing a mobile phone in one or two years, or are willing to change a new battery, the impact will be minimal for you.

At present, most companies that provide fast charging solutions have not given the impact on battery life from the perspective of batteries. However, after 500 times of battery charging and discharging under my country’s standards, the battery capacity is more than 80% qualified, and within one year It has little effect on use.

If you want to use your phone for 2-4 years without replacing the battery, the following suggestions may help you:

Reduce the number of fast charging and use it only when you need it urgently; fast charging when the battery is only about 30% remaining instead of 3%; when using fast charging, it is better not to run large memory games.

Post time: Jun-08-2021