Lithium-ion battery VS lithium metal battery

Lithium element has a wide range of applications in our daily lives, among which the common ones are the lithium batteries used in our phones and computers that we cannot do without in our daily lives. Therefore, we often hear concepts such as "lithium battery", "lithium-ion battery", "lithium metal battery" in our ears. Are they the same thing? If not, what is the relationship between them?

Firstly, both lithium-ion batteries and lithium metal batteries are types of lithium batteries. As for lithium-ion batteries, they are accompanied by the insertion and extraction of equivalent electrons with lithium ions, and lithium-ion batteries have always been rechargeable batteries (secondary batteries).

But in fact, the charging and discharging process of lithium metal batteries is also accompanied by migration in the electrolyte, so strictly speaking, lithium metal batteries are a special type of lithium-ion battery.

In this definition, the difference between the two is very clear: in lithium-ion batteries, lithium element only exists in the form of+1 valence Li+, and there is no electron gain or loss during the charging and discharging process, and it will not change from Li+ to elemental lithium; In lithium metal batteries, the lithium element undergoes corresponding valence state changes during the charging and discharging process.

Lithium metal has strong reactivity, so it gradually disappeared and was replaced by lithium-ion batteries. But after a century of development, current technology can effectively achieve the dissolution and deposition of lithium metal during charging and discharging processes. Therefore, the vast majority of lithium metal batteries reported in scientific research papers are secondary batteries, rechargeable batteries, such as the popular lithium sulfur battery that uses lithium metal.

The memory effect of lithium-ion batteries refers to the ability of the battery to remember the user's daily charging and discharging amplitude and pattern, which is difficult to change over time and cannot be charged or discharged significantly. This is because the previous battery used nickel cadmium batteries, which have larger and coarser cadmium grains, if nickel cadmium batteries are recharged before they are fully discharged, cadmium grains are prone to agglomerate and form secondary discharge platforms during battery discharge. The battery will store this discharge platform and use it as the endpoint of discharge in the next cycle. But lithium-ion batteries do not have this effect, so you can use them with confidence.