All-solid-state batteries are inevitable in China, as carmakers and battery makers are making breakthroughs in the technology that promises to rid electric vehicle owners of mileage anxiety, said a senior EV and battery expert.

Such batteries use solid electrolytes instead of liquid or gel electrolytes. They have the potential to be safer, more energy dense and faster charging than traditional batteries.

Ouyang Minggao, an academician of the Chinese Academy of Sciences, estimates that China will see such batteries first installed in EVs from 2027, with mass production estimated to start by around 2030.

Ouyang, also vice-president of the China EV 100 and a professor at Tsinghua University, made the prediction last week at an industry meeting held by the China EV 100.

"The year 2024 was a milestone in the development of China's all-solid-state batteries sector; we filed three times more patents in the field than Japan," said Ouyang.

He said major battery makers are working on sulfide-based all-solid-state batteries, which, paired with high-nickel ternary positive and silicon-carbon negative materials, aim to achieve performance targets of 400 watt-hours per kilogram in energy density and more than 1,000 charging life cycles.

Sun Huajun, chief technology officer of BYD Lithium Battery, the battery firm for China's largest NEV maker, said it plans to begin small-scale production of sulfide-based all-solid-state batteries by 2027.

"These batteries are expected to be incorporated into mainstream EV models by 2030," said Sun at an industry meeting earlier this month.

State-owned Changan said it will launch a demo car with solid-state batteries, with all-solid-state ones to be gradually mass-produced from 2027. They are designed to have an energy density of 400 Wh/kg, with a range reaching 1,500 kilometers.

Voyah, a premium arm of Dongfeng Motor, said it is working on its third-generation all-solid-state batteries.

Voyah is one of the first carmakers in China to develop the technology. Back in 2021, its semisolid-state batteries were installed in vehicles, with their energy density reaching 230 Wh/kg.

Last week, Mercedes-Benz announced that it had started road tests of an EQS sedan with prototype all-solid-state batteries codeveloped by Factorial Energy, a US-headquartered battery maker.

The German carmaker said the prototype solid-state battery was integrated into the vehicle in late 2024 after intensive testing.

The first laboratory vehicle tests were conducted in Stuttgart, Germany, at the end of 2024 to prepare for the road tests that started in February.

The German carmaker said the model's range can reach 1,000 km on one charge, up 25 percent compared with those equipped with conventional batteries.

Analysts at Soochow Securities said established carmakers overseas may become the first to launch vehicles with all-solid-state batteries.

But Ouyang said it is "no big deal" if such batteries are first installed elsewhere one year ahead of the estimated time in China.

"We are the leading player in the power battery sector. They are not overtaking or overthrowing us in the sector by installing such batteries one year earlier than us," he said.

He explained that it is a long-term issue, adding that it will take five to 10 years for all-solid-state batteries to grow its market share to just 1 percent.