BEIJING, April 17 (Xinhua) -- Scientists have identified materials that contract upon heating, which enables the rejuvenation of aging lithium-ion batteries with nearly 100 percent voltage recovery.

The achievement, made by a research team at the Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), in collaboration with researchers from the University of Chicago and other institutions, has not only advanced battery technology with high energy density and durability, but also promises to revolutionize future material design and application.

The related findings have been published in the journal Nature.

To push the operational boundaries of electric vehicles and aircraft, next-generation high-energy-density lithium-ion battery technology needs to be upgraded, said team leader Liu Zhaoping, a researcher at the NIMTE.

As a core component of batteries, cathode materials play a vital role in energy storage and release through chemical reactions during charging and discharging. They critically influence battery energy density, cycle life, safety and production cost.

Lithium-rich layered oxide cathode materials deliver record capacities of over 300 mAh/g, exceeding commercially available cathode materials. This material can boost battery energy density by over 30 percent while maintaining significant cost advantages.

However, balancing high energy density and long-term stability in batteries based on lithium-rich layered oxide cathode materials remains challenging: after repeated charging cycles, the voltage gradually decays, leading to battery aging.

The team discovered negative thermal expansion behaviour of lithium-rich layered oxide cathode materials, which contract when heated within the temperature range of 150 to 250 degrees centigrade.

A novel electrochemical method was developed to reset aged lithium-rich layered oxide cathode materials from structurally disordered and unstable states to their original ordered state.

"By intelligently adjusting charging strategies, structural defects in the cathode can be periodically repaired, thereby significantly extending battery lifespan," said Qiu Bao, a lead author of the study.

Based on a robust predictive framework, the team designed the world's first zero thermal expansion cathode, which exhibits minimal volume change under temperature fluctuations.

This advancement could address issues such as shortened battery life caused by thermal variations, unlocking new possibilities for next-generation high-energy-density lithium battery technology.

With the integration of advanced experimental techniques and artificial intelligence, material design is evolving toward on-demand customization. In the future, lithium-ion batteries promise to break the conventional range-lifespan trade-off, enabling electric vehicles and aircraft to enjoy both extended ranges and ultra-long lifespans, experts said.

"The implications of these findings extend beyond the field of battery research, which is original, interesting and important for offering new principles for designing functional materials," reviewers from Nature commented.