The study, led by Professor Jin Ho Bang and PhD scholar JinHa Shim, reveals that manganese—an element typically added to stabilize nickel-rich cathodes—can become a liability if exposed to air before synthesis. This exposure causes manganese atoms on the particle surface to undergo Jahn-Teller distortion. These defective regions act as catalysts for electrolyte breakdown and transition-metal dissolution, leading to rapid performance decay during regular use.

To address this, the researchers propose a precise adjustment to manufacturing protocols rather than costly material redesigns. By increasing the ratio of lithium during the synthesis process, the team successfully suppressed the formation of these reactive surface phases. This method restores stable manganese-oxygen bonding and allows cathodes to retain over 90% of their capacity throughout extended cycling tests. The findings, published in Energy and Environmental Science, underscore that managing the storage history of precursors is as vital to battery durability as the quest to eliminate cobalt.