What Is An All-solid-state Lithium Battery?

All-solid-state lithium battery is a lithium battery that uses solid electrode materials and solid electrolyte materials and does not contain any liquid. It mainly includes all-solid-state lithium-ion batteries and all-solid-state metal lithium batteries. The difference is that the former does not contain metal lithium in the negative electrode, and the latter The negative electrode is lithium metal.

Traditional liquid lithium-ion batteries and all-solid-state lithium-ion batteries From the time point of their emergence, all-solid-state metal lithium batteries are earlier than liquid lithium-ion batteries, but in the early days, the electrochemical performance, safety, Engineering manufacturing has been unable to meet application requirements. Through continuous improvement, the comprehensive technical indicators of liquid lithium-ion batteries have gradually met the application needs of the consumer electronics market, and have since been accepted by more markets. From the perspective of technological development trends, compared to liquid lithium-ion batteries, all-solid-state metal lithium batteries may have the advantages of good safety performance, high energy density and long cycle life. In recent years, solid electrolyte materials, especially sulfide electrolyte materials, have made major breakthroughs in ionic conductivity. Therefore, all-solid-state lithium battery technology has gradually begun to attract the attention of research and development institutions and large enterprises worldwide.

Classification of all solid-state lithium batteries:

With the rise of the all-solid-state lithium battery craze, various "all-solid-state" or "solid-state" lithium batteries have appeared one after another, and there is a status quo of confusion. The seven types of concepts related to solid-state lithium batteries that have emerged are sorted out and a preliminary summary is made.

Liquid lithium batteries: Lithium batteries that do not contain solid electrolytes during the manufacturing process but only contain liquid electrolytes, including liquid lithium ion batteries and liquid metal lithium batteries.

Gel electrolyte lithium battery: The liquid electrolyte in the battery core is in the form of gel electrolyte, and the battery core does not contain solid electrolyte, which actually belongs to the category of liquid lithium ion batteries.

Semi-solid lithium battery: In the electrolyte phase of the cell, half of the mass or volume is solid electrolyte, and the other half is liquid electrolyte; or the electrode at one end of the cell is all solid and the other electrode contains liquid.

Quasi-solid lithium battery: The electrolyte of the cell contains a certain amount of solid electrolyte and liquid electrolyte, and the mass or volume of the liquid electrolyte is less than the proportion of the solid electrolyte.

Solid-state lithium battery: A battery that contains a higher mass or volume ratio of solid electrolyte and a small amount of liquid electrolyte in the battery is called "solid-state lithium battery" by some researchers, but this is actually not an all-solid-state lithium battery. Hybrid solid-liquid lithium battery: Both solid electrolyte and liquid electrolyte exist in the battery cell. Including the aforementioned semi-solid, quasi-solid, and solid-state lithium batteries, all of which are hybrid solid-liquid lithium batteries. Since there is no need to artificially classify according to the solid-liquid ratio, and there will be no ambiguity, it is recommended to use this term, which can also be called "mixed solid-liquid electrolyte lithium battery".

All-solid-state lithium battery: The battery core is composed of solid-state electrodes and solid-state electrolyte materials. The battery core does not contain any mass and volume fraction of liquid electrolyte within the operating temperature range. It can also be called "all-solid-state electrolyte lithium battery". Those capable of charging and discharging cycles can be further referred to as "all solid state lithium secondary batteries" or "all solid electrolyte lithium secondary batteries".

In summary, according to different electrolytes, lithium batteries can be divided into three categories: liquid lithium batteries, mixed solid-liquid lithium batteries and all-solid lithium batteries. According to the difference of the negative electrode, it can be divided into a lithium metal battery whose negative electrode is lithium metal, and a lithium ion battery whose negative electrode does not contain lithium metal.