On May 22, the Chinese Society of Automotive Engineers released a group standard for evaluating solid-state batteries, defining their characteristics for the first time. This standard addresses industry ambiguity and the lack of testing methods, supporting technological advancements and industrial applications.
The standard specifies that solid-state batteries must rely entirely on solid electrolytes for ion transfer, distinguishing them from hybrid solid-liquid electrolyte batteries. It introduces a weight loss-based test for liquid content, using vacuum heating to measure weight loss. A battery is classified as solid-state if no liquid is visible and the weight loss rate is below 1%. Validated through multiple experiments, this method offers low error rates and stable results across various technical approaches.
Solid-state batteries are considered the future of power batteries due to their high safety and energy density. However, the absence of unified standards has led to inconsistent definitions and market confusion. The new standard provides a consistent benchmark for research, certification, and market adoption.
BMW and Mercedes Advance Solid-State Battery Testing
Solid-state batteries offer two key advantages: higher safety and energy density compared to conventional power batteries, and better resistance to extreme low temperatures, reducing combustion risks and enhancing vehicle safety.
On May 20, BMW began road testing electric vehicles equipped with solid-state batteries, marking a significant step in its battery technology development. The company has integrated sulfide electrolyte prismatic batteries, developed by Solid Power, into its i7 sedan. These battery modules have been redesigned to fit BMW¡¯s fifth-generation electric drive platform.
BMW¡¯s collaboration with Solid Power began in 2022. In December 2022, BMW announced plans to establish a solid-state battery prototype production line at its Cell Manufacturing Competence Center in Parsdorf, incorporating Solid Power¡¯s technology. Over the coming months, BMW will continue optimizing sulfide-based solid-state battery electrolytes to enhance performance.
Mercedes is also actively pursuing solid-state battery technology. The company recently tested Factorial Energy¡¯s solid-state battery design in its EQS sedan, targeting a range exceeding 621 miles. Factorial¡¯s solid-state batteries are expected to be 40% lighter than conventional lithium-ion batteries.
