Chinese scientists develop materials allowing all-solid-state lithium batteries to maintain 80% of initial capacity after 5,000 cycles of usage

Chinese scientists from the Qingdao Energy Institute of the Chinese Academy of Sciences have developed homogenized cathode materials, allowing all-solid-state lithium batteries to maintain 80 percent of their initial capacity after 5,000 cycles of usage.

The breakthrough was published recently in Nature Energy titled "a cathode homogenization strategy for enabling long-cycle-life all-solid-state lithium batteries."

The researcher team led by Cui Guanglei and assisted by Ju Jiangwei, Cui Longfei and Zhang Shu, designed homogeneous cathode materials that have revolutionized the paradigm of composite cathodes in solid-state lithium batteries. A solid-state lithium battery constructed with 100 percent active materials maintains 80 percent of its initial capacity after 5,000 cycles.

This innovation has addressed the challenges arising from the traditional solid-state lithium batteries, resulting in the production of solid-state lithium batteries with high energy density and long cycle life. 

Typically, solid-state lithium batteries involve using composite electrodes containing active electrode materials, conductive electrons, and ion-conducting additives. But there are difficulties in achieving a perfect match between the different components in terms of chemical, electrochemical, and mechanical properties, leading to various interface issues that significantly degrade the battery's energy density and lifespan.

According to the published paper, the material's ion and electron conductivity surpass traditional layered oxide cathode materials  over 1,000 times of existing technology, with a specific capacity exceeding current high-nickel cathode materials.

The material experiences only a 1.2 percent volume change during the charge-discharge process, significantly lower than the 50 percent volume change seen in traditional layered oxide cathode materials. 

The high conductivity ensures normal charge-discharge without the need for additional conductive additives, while the low volume change guarantees structural stability during the battery's operation.