China’s tech giant files solid-state EV battery patent with layered electrode design

Battery design features a volume efficiency of 77.8%

According to the company, the design is compatible with existing lithium battery manufacturing lines, which could simplify future mass production and support a smoother transition to solid-state technology, CarNewsChina reports.

Xiaomi notes that its prototype features a cell-to-body (CTB) design with a volume efficiency of 77.8%. The battery pack measures only 120 mm (about 4.7 inches) in height, including the vehicle floor, enabling better space utilization and improved weight distribution. It delivers a CLTC-rated range of over 745 miles and supports fast charging that adds 500 miles of range in just 10 minutes.

Although solid-state batteries are unlikely to be widely adopted before 2030, Xiaomi’s involvement reflects increasing momentum in the industry. With growing investment from automakers and battery manufacturers, solid-state technology is gradually approaching commercial viability, especially with Chinese companies playing a leading role.

The company’s move also reflects a growing industry-wide focus on solid-state battery technology, widely regarded as essential for safer, more efficient, and longer-lasting energy storage, with major global companies like CATL, BYD, Toyota, SAIC, and BMW also investing heavily in similar next-generation battery innovations.

Automakers push solid-state batteries toward commercial rollout

Progress is accelerating in the development of solid-state batteries as BMW begins road testing a prototype i7 model equipped with this technology. At the same time, battery maker CATL and automaker SAIC are targeting small-scale production by 2027. 

Toyota also plans to launch its first solid-state battery vehicles between 2027 and 2028, highlighting growing momentum across the automotive industry for next-generation energy storage solutions. Replacing the liquid electrolyte in traditional lithium-ion cells with solid materials, solid-state batteries offer improvements in energy density, safety, and thermal stability.

Despite the potential benefits, major challenges remain, including low ionic conductivity, problems with interfacial contact, and the formation of lithium dendrites. Researchers are exploring three main types of solid electrolytes—sulfide, oxide, and polymer—each offering different balances of conductivity, stability, and ease of manufacturing.

Furthermore, experts suggest the latest patent could allow Xiaomi to integrate its own solid-state batteries into upcoming electric vehicles, like a successor to the SU7, cutting reliance on third-party suppliers such as CATL and BYD.