China set to draft rules on solid-state batteries

A proposal submitted by China to develop the first international standard for solid-state batteries used in electric vehicles has been approved by the International Electrotechnical Commission, amid growing efforts by Chinese automakers and battery producers to advance vehicle validation and pilot production.

The State Administration for Market Regulation said earlier this month that the project would cover guidance on applications, test items and test conditions for solid-state lithium-ion cells used to power electric road vehicles.

China will lead the drafting, with experts from France, South Korea and Japan participating, according to the SAMR.

The SAMR said the proposed standard would give automakers around the world a common reference for developing and producing solid-state batteries.

Ji Xuehong, director of the Automotive Industry Innovation Research Center at North China University of Technology, said the industry was pursuing multiple technical routes and lacked consistent terminology, testing standards and methods. A common framework could help avoid unnecessary duplication and the inefficient use of resources.

Yang Weibin, an expert on new energy vehicles and power batteries, said the standard, once finalized, will also lower the costs associated with technical coordination and product validation for Chinese companies entering overseas markets.

The approval marks the start of standard development, rather than the publication of a final standard. Yang said the process will take two to three years and involve international negotiations and voting before the standard can be finalized and published. Yang added that China's battery industry has strong manufacturing capabilities but still needs to strengthen fundamental research.

Conventional lithium-ion batteries typically use flammable liquid electrolytes, which can pose safety risks if cells are damaged or overheat. Solid-state battery technology uses solid electrolytes and is being developed for its potential to improve safety and offer higher energy density.

Ji said solid-state battery technology worldwide remains at the research and testing stage and has yet to enter large-scale commercial use.

China's latest automotive technology road map, compiled by the China Society of Automotive Engineers under the guidance of the Ministry of Industry and Information Technology, projects small-scale use of all-solid-state batteries by 2030 and large-scale adoption worldwide by 2035.

Sun Huajun, chief technology officer of BYD Lithium Battery, said at an industry forum in February 2025 that BYD plans to begin small-scale production of sulfide-based all-solid-state batteries by 2027, with the batteries expected to be used in mainstream electric vehicle models by 2030.

Changan Automobile has said it expects to complete vehicle validation of solid-state batteries in 2026 and take initial steps toward mass production of all-solid-state batteries in 2027.

Gu Chunshan, vice-president of Chery Automobile, said in March that the company aims to begin vehicle validation of all-solid-state batteries in 2027. Chery said its pilot line has produced cells with different energy densities and that the cells are undergoing testing.

Yang Weibin said commercializing all-solid-state batteries will require further technological breakthroughs, including solutions to problems at the interfaces between solid components inside battery cells.

Yang Hongxin, chairman and CEO of Chinese battery maker Svolt Energy, said the industry will need more time to develop lower-cost manufacturing processes and achieve economies of scale.

He said the material and manufacturing costs of all-solid-state batteries in 2027 are expected to be several times those of conventional ternary lithium-ion cells using liquid electrolytes. He also expected large-scale commercialization of all-solid-state batteries to begin after 2030.

wangyuchen@chinadaily.com.cn