[DigitalToday reporter Jae-won Choi] China's CATL, the world's largest electric vehicle battery maker, is accelerating development of next-generation solid-state batteries. It has entered the stage of trial production of 20 ampere-hour (Ah) battery cells. It aims to start limited production in 2027.

Electrek reported on Oct. 28, local time, that CATL said in a recent response to investor questions, "We are continuously investing in solid-state battery research and development and plan to begin limited production next year."

CATL is developing solid-state batteries using sulphide-based solid electrolytes. It is currently conducting trial production of 20Ah cells. It has set a target of achieving an energy density of 500 watt-hours per kilogram (Wh/kg).

Solid-state batteries replace the liquid electrolyte in existing lithium-ion batteries with a solid. They are drawing attention as next-generation batteries because they can improve energy density and safety, but technical challenges remain for mass production.

The sulphide-based electrolyte adopted by CATL has the advantage of high ionic conductivity and good processability. On the other hand, it is difficult to maintain stable contact between the electrode and electrolyte during charging and discharging.

As a result, even if it has entered the trial production stage, additional verification is needed on durability and safety, production yield and price competitiveness before applying it to actual electric vehicles.

CATL expects initial production volume to be limited. It sees the timing of full-scale mass production as around 2030.

CATL Chairman and CEO Robin Zeng (로빈 젱) said at the Summer Davos Forum in June that he assessed the maturity of solid-state battery technology at stage 4 out of 9. That means technical completeness for mass production is not yet sufficient.

Competition in the global battery industry is also intensifying. Toyota aims to launch electric vehicles equipped with solid-state batteries in 2027 to 2028. Samsung SDI is pushing to mass-produce solid-state batteries in the second half of 2027 and is considering humanoid robots as an initial commercialisation target.

BYD also plans to start limited production of sulphide-based solid-state batteries in 2027 and expand production scale by 2030.

CATL, meanwhile, maintained its No. 1 position in the global EV battery market with a 39.4 percent share from January to August this year. Attention is focused on whether CATL, which leads the conventional battery market, can also secure competitiveness in solid-state batteries.