Oxide/sulfide/polymer, three major technical routes for all-solid-state batteries

Recently, the news of the breakthrough of solid-state batteries has stirred up a lot of waves in the market. After all, this is the next generation of battery technology recognized by the market. Any change in solid-state battery technology will directly affect the development of lithium batteries , and related companies cannot ignore it.

From the perspective of technical route, just like various technical routes such as ternary batteries, lithium iron phosphate batteries , and lithium manganese oxide batteries , solid-state batteries are also divided into three major technical routes.

The three major technical routes of solid-state batteries are: one is polymer, one is sulfide, and the other is oxide all-solid-state battery.

Each technology route has its advantages and disadvantages. Toyota chose the sulfide route, Ilika chose the oxide route, and the French company Bollore chose the polymer route.

Toyota is the first company to enter the research of all-solid-state batteries. Comparing sulfur-based and oxide-based batteries: In terms of chemical properties, oxide-based solid-state batteries are more stable, while sulfur-based batteries are relatively poor. In terms of other indicators such as conductivity and interface impedance, there is not much difference.

In terms of processing cost, sulfur-based processing costs are relatively high, while oxide-based processing costs are relatively low. However, from the perspective of integration, sulfur-based processing is easier, while oxide-based processing is relatively weak.

From the perspective of polymers, compared with sulfur and oxides, they do not have an advantage. However, they still have some advantages, such as easy integration. The manufacturing cost of polymer solid-state batteries is also a disadvantage. France's Bolloré solid-state batteries have actually been equipped with more than 2,000 cars, but they have no advantages in thermal management. Polymer solid-state batteries must ensure the temperature difference of the battery, and have high requirements for thermal management of the battery, which creates a heavy burden and requires high energy and cost, which increases the difficulty of mass production of polymer solid-state batteries.

The market believes that the sulfur system is very good, and the various indicators and demonstration effects of sulfide solid-state batteries after installation are good. However, Toyota announced in 2017 and 2018 that it would mass-produce all-solid-state batteries in three years, but in fact, it has not yet been mass-produced. The main reason for not mass-producing, or the biggest problem, is that the chemical stability of the sulfur system is relatively poor, which leads to the need for additional protection measures on the production line, and more protection methods need to be considered in the design, including packaging.

On the other hand, after the battery is made, it is very fragile during operation. In general, sulfur technology is very good, even better than oxide technology to some extent, but the biggest obstacle to the commercialization of sulfur-based all-solid-state batteries is cost.

Oxides also have technical difficulties, but once the technical difficulties of oxide all-solid-state batteries are overcome, their cost competitiveness will be very strong in commercial use and large-scale mass production.

Of course, it is still impossible to judge which technical route will ultimately win.