LG Energy Solution and Seoul National University have developed a method to suppress gas evolution in lithium manganese-rich (LMR) cells, a key barrier to their use in large-format electric vehicle (EV) batteries. The findings, from joint research with Professor Jongwoo Lim’s chemistry team, have been published in Nature Communications.

LMR cathodes achieve high energy density using both transition-metal and oxygen activity, substituting low-cost manganese for cobalt. Incomplete oxygen recovery during discharge generates gas that increases internal pressure in large-format cells, restricting their use in EVs.

Lowering the upper charge voltage from 4.6 V to 4.3 V raised oxygen recovery from 86% to 97%, while reducing the discharge cutoff from 3.0 V to 2.0 V enabled near-complete oxygen restoration. Applied to 40 Ah-class large-format cells with a lower-temperature formation process, this approach produced 92.2% energy retention after 883 cycles.

In a statement, Professor Jongwoo Lim of Seoul National University said: “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. We confirmed that achieving long-term stability in LMR batteries requires comprehensive consideration of not only charging conditions but also discharge conditions.”

Source: LG Energy Solution