Solid state battery safety is no longer absolute, according to announcements on the internet on December 20, 2025. Car News China lead with the story, and Interesting Engineering followed through. Apparently this news originates from battery scientists, who warn we cannot rate the technology as inherently, or absolutely safe.
Why Are We Challenging Solid Safety Now?
The 2025 World Power Battery Conference in China attracted top battery scientists from November 12 to November 15, 2025. The general consensus appears to be that solid-state batteries contain energy-dense chemicals, with potential to trigger thermal runaway.
If this is the case, then we can no longer speak of absolute solid state battery safety. Especially since Interesting Engineering points out that some of these products contain flammable lithium metal.
Lithium’s high reactivity, they continue, presents ongoing safety challenges that battery manufacturers must address. New solutions must be found in materials engineering, cell design, and manufacturing solutions, Car News China insists.
The Fundamental Problems Still With Us
Changing battery electrolyte does not do away with this reality: lithium metal can still react with cathode materials without requiring oxygen. This can trigger high heat at extreme levels leading to fires, and sometimes even explosions.
The threat of dendrites forming between electrodes has not gone away either. There may no longer be a liquid or gel electrolyte that is easy to penetrate. But there could still be microscopic defects, or grain boundaries in solid electrolytes that dendrites can worm through.
Where Does That Leave Solid State Battery Safety?
Adrian Leung, writing in Car News China, suggests new-energy auto makers should not drop their guard on solid state battery safety, while they continue to explore the technology. Instead, they need to continually and rigorously validate safety performance, he says.
This should not be a call to abandon solid state battery technology incorporating lithium metal, Adrian Leung believes. Perhaps the answer lies in taking the best of both worlds, and moving forward with a mix of conventional and solid state lithium batteries.
More Information
Fast-Charging Solid-State Battery From China
The Toyota Solid-State Battery Project
Preview Image: NASA’s Solid-State Batteries
