What is the working principle of lithium battery?

Many customers do not understand the working principle of lithium batteries. This article combines the characteristics of electronics and lithium ions to talk about its related knowledge.

What is the working principle of lithium battery?

The working principle of lithium batteries is developed by Utilizing the characteristics of "lithium ions can carry electrons". Lithium batteries are generally made of "lithium compounds" and "carbon materials", and lithium ions can be intercalated or deintercalated in these two materials. During the process of this phenomenon, electrons will also migrate with lithium ions. This process can be understood as the process of battery charging and discharging. The internal structure, material, and applied technology are different, and this will determine the overall performance of the battery, especially the lithium battery.

Charge and Discharge Process

As we all know, batteries are divided into positive and negative electrodes. The positive electrode is generally made of "lithium compound" material, while the negative electrode is made of "carbon material". The areas where the positive electrode and the negative electrode are located are not connected. There will be a separator and electrolyte in the middle. Based on the difference in battery brand, structure, and application technology, the overall structure, volume, and internal distribution of the battery will change slightly. Lithium ions are generally generated in the positive electrode area, and then carry electrons through the electrolyte to the negative electrode area, and intercalation occurs. This phenomenon is reversible, which is the so-called charging and discharging process, which means that lithium ions in the negative electrode area can also return to the positive electrode area, which is called deintercalation.

Normally, people call lithium ions carrying electrons into the negative electrode area as charging, and vice versa from the negative electrode to the positive electrode, which is called discharging, but there is another point that cannot be ignored, that is, there must be a "load" in the entire cycle circuit, which is the so-called power consumption device.

Lithium battery structure

If you look closely at the structure of a lithium battery, it is more complicated, but if you look at the large structure, it can be divided into three parts, usually divided into the positive electrode area, which is also the area where lithium ions are generated and departed, and the negative electrode area is also the area where lithium ions are intercalated or deintercalated.
However, it should be noted that lithium ions can be intercalated or deintercalated at the positive electrode, but the positive electrode and the negative electrode do not communicate with each other (there are multiple channels through which lithium ions can pass), and there is a diaphragm, which is the electrolyte (not to be true, for the sake of understanding), only lithium ions carrying electrons can shuttle in the electrolyte and transport electrons back and forth.

The battery bulging phenomenon that occurs in daily life is also related to the shuttle of lithium ions. If lithium ions carry a large number of electrons to the negative electrode area, if these charged lithium ions cannot be stored, overcharging and bulging will occur. Otherwise, it will be overdischarging. Although the direction is positive and negative, the principle is the same. 

Conclusion: The principle of lithium batteries is the same as that of lead-acid and nickel batteries, but after years of research, it is found that lithium ions are more suitable as the medium for electron transfer than positive and negative electrode materials in other batteries.