In fact, you do nâ€™t know the correct charging method

How long does it take to charge the laptop for the first time? The merchant's explanation is that it must be more than 10 hours to ensure that the laptop battery is fully activated. Although we use our laptop batteries very carefully, the standby time of books is still getting less and less. So how to charge the laptop battery is the most appropriate?

Wonderful introduction: DIY turns waste into treasure laptop battery turns into mobile power tutorial

In-depth analysis of laptop battery materials

The positive electrode material of a lithium ion battery is usually composed of an active compound of lithium, and the negative electrode is carbon with a special molecular structure. The main component of the common positive electrode material is LiCoO2. When charging, the potential applied to the two electrodes of the battery forces the positive electrode compound to release lithium ions and insert it into carbon in which the negative electrode molecules are arranged in a layered structure. During discharge, lithium ions are precipitated from the carbon in the lamellar structure and recombine with the positive electrode compound. The movement of lithium ions generates electric current.

Although the principle of chemical reaction is very simple, in actual industrial production, there are many more practical issues to be considered: the material of the positive electrode needs additives to maintain the activity of multiple charging and discharging, and the material of the negative electrode needs to be designed at the molecular structure level. Accommodate more lithium ions; the electrolyte filled between the positive and negative electrodes, in addition to maintaining stability, also needs to have good conductivity to reduce the internal resistance of the battery.

Although lithium-ion batteries rarely have the memory effect of nickel-cadmium batteries, the principle of the memory effect is crystallization, and almost no such reaction occurs in lithium batteries. However, the capacity of lithium-ion batteries will still decline after multiple charge and discharge, the reasons are complex and diverse. It is mainly the change of the positive and negative electrode materials. From the molecular level, the hole structure containing lithium ions on the positive and negative electrodes will gradually collapse and block; from a chemical point of view, the positive and negative electrode materials are active and passivated, and side reactions occur to generate stable Other compounds. Physically, the positive electrode material will gradually peel off. In short, the number of lithium ions in the battery that can move freely during charging and discharging will eventually be reduced.

Overcharge and overdischarge will cause permanent damage to the positive and negative electrodes of the lithium ion battery. From a molecular level, it can be intuitively understood that excessive discharge will cause the negative electrode carbon to excessively release lithium ions and cause its sheet structure to collapse. Overcharging will force too many lithium ions into the carbon structure of the negative electrode, so that some of the lithium ions can no longer be released. This is why lithium-ion batteries are usually equipped with control circuits for charging and discharging.