BYD patents new solid‑state battery cathode to curb degradation

BYD has filed a patent for a composite cathode material for solid‑state batteries that combines halide and sulfide electrolyte particles. The design aims to keep stable contact between solid components during charge‑discharge cycles, addressing a key degradation issue that raises internal resistance and reduces capacity over time.

The filing expands BYD’s solid‑state battery portfolio following earlier patents on membrane structures. BYD’s battery‑cell CTO Sun Huajun noted that the active cathode material accounts for over 85 % of the cell architecture, though no performance data has been released. Industry analysts, including CATL CEO Robin Zeng, say large‑scale production remains years away, while research from the Chinese Academy of Sciences supports the benefit of smaller sulfide particles for long‑term performance.