File photo/NBD

On the afternoon of April 12, CATL officially announced that it will release a new generation of solid-state battery technology on April 19th during the Shanghai International Automobile Industry Exhibition.

Last June, CATL Chairman Zeng Yuqun revealed that CATL's solid-state batteries were already under development. In August, CATL's Chief Scientist Wu Kai revealed that CATL plans to launch a new generation of battery cell solid-state batteries in 2023. Solid-state batteries have the characteristics of high safety, high reliability, and good cycle life.

What are solid-state batteries? Some industry insiders say that CATL's solid-state batteries can be understood as a kind of solid-liquid mixture battery (semi-solid battery), which is closer to polymer batteries. Compared with fully solid-state batteries that do not contain liquid electrolytes, there is still some electrolyte in the battery, and its safety will be better than that of ordinary lithium-ion batteries.

In the view of some industry insiders, CATL's solid-state batteries should be a kind of solid-state battery with a special design of battery material structure. A doctoral student in materials science and engineering at Beijing University of Science and Technology further speculated that CATL's solid-state batteries may be a new type of gel battery.

There are two routes for gel batteries. One is a gel polymer membrane battery, in which the membrane is a gel electrolyte, and the internal contains non-flowing liquid electrolyte, but can conduct lithium ions; while the electrode is still a traditional electrode, a solid porous electrode, and the pores are filled with electrolyte.

The other is a gel electrode battery, in which the membrane is a gel electrolyte, and the positive and negative electrodes are also in a gel state, connected to each other to form a network space structure, and the non-flowing electrolyte is filled in the gaps. The polymer and metal ions are complexed, and the gel electrolyte can conduct lithium ions.

Among the two routes, what CATL mentioned is more likely to be the second type of battery.