A joint team led by Researcher HUANG Xuejie of the Institute of Physics, Chinese Academy of Sciences (IOP, CAS), together with Huazhong University of Science and Technology and Ningbo Institute of Materials Technology & Engineering, has developed an anion-regulation technology that solves the long-standing interphase-contact problem between the solid-state electrolyte and the lithium-metal electrode, offering a key technical step toward commercialization. The findings were published on 7 October in Nature Sustainability.

All-solid-state lithium-metal batteries are regarded as a next-generation energy-storage technology, but poor interphase contact has remained a major barrier. Traditional methods rely on bulky external-pressure devices, yet tiny voids and cracks still form between the lithium anode and the electrolyte, shortening battery life and creating safety risks.

To overcome this challenge, the researchers introduced iodide ions into the electrolyte. During cell operation, the iodide ions migrate to the electrode interface under the electric field, forming an iodine-rich interphase that actively attracts lithium ions and automatically fills every gap and pore, keeping the electrode and electrolyte in intimate contact at all times.

Prototype cells fabricated with the new technology retained stable performance after hundreds of charge–discharge cycles, far exceeding current benchmarks. The design is simpler to manufacture, uses fewer materials and promises longer service life. It is expected to provide a safer and more efficient energy solution for humanoid robots, electric aviation and electric vehicles.

Professor WANG Chunsheng, a solid-state-battery expert at the University of Maryland, commented: “This study removes the critical bottleneck hindering the commercialization of all-solid-state batteries and represents a decisive step toward their practical use.”