Lithium manganese-rich battery cuts gas buildup, lasts 883 cycles

Researchers have found a way to suppress gas buildup in lithium manganese-rich (LMR) batteries, a major hurdle to using the technology in large electric vehicle cells. Tests showed that optimized 40 Ah-class cells retained 92.2 percent of their initial energy after 883 charge-discharge cycles. The approach works by controlling how oxygen reacts inside the battery during charging and discharging. Researchers from LG Energy Solution and Seoul National University found that adjusting the cell's voltage range can improve oxygen recovery and reduce reactions that generate gas. Gas formation is a major concern in large-format batteries because there is limited space inside the cell to accommodate rising internal pressure. It can also damage the battery's internal structure and contribute to performance degradation. The researchers tested different charging and discharging conditions to determine how they affected oxygen reversibility in LMR cathodes. They found that both the upper charging voltage and the discharge cutoff voltage play a role in restoring oxidized oxygen to its original state. Lowering the upper charging voltage from 4.6 V to 4.3 V increased the reduction of oxidized oxygen from 86 percent to 97 percent. Lowering the discharge cutoff voltage from 3.0 V to 2.0 V also allowed oxygen to recover to nearly its original state. LMR cathodes use manganese as a major material and can avoid cobalt, potentially lowering material costs. The cathodes also store energy through reactions involving oxygen as well as transition metals such as nickel and manganese. Based on the oxygen-reaction findings, the researchers redesigned the operating voltage range and formation conditions for 40 Ah-class cells. They also used a lower-temperature formation process to further suppress gas generation. The resulting cells retained 92.2 percent of their initial energy after 883 cycles, showing that the strategy can maintain stability in a large-format cell rather than only in smaller laboratory-scale batteries. The researchers said the findings point to electrochemical protocol design as a way to improve LMR battery stability without relying solely on changes to the battery materials themselves. 'This study identified the causes of degradation in LMR batteries from the perspective of oxygen reversibility and demonstrated that cell stability can be improved through electrochemical protocol design alone,' said Professor Jongwoo Lim of Seoul National University. 'We confirmed that achieving long-term stability in LMR batteries requires comprehensive consideration of not only charging conditions but also discharge conditions.' The results could help advance LMR technology toward larger cells needed for EV applications, where gas generation and long-term durability have been significant challenges. 'This research addresses one of the key challenges facing LMR batteries,' said an LG Energy Solution spokesperson. 'It demonstrates that stable battery life can be secured even in large-format cells by effectively suppressing gas generation, providing an important foundation for growth in the next-generation LMR battery market.' The study was published in Nature Communications. Get the latest in engineering, tech, space & science - delivered daily to your inbox. With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn't chasing stories, she's likely lost in a book or enjoying the company of her dogs.