The cause of pressure rise, gas generation, and performance degradation in batteries based on the low-cost “lithium-manganese-rich layered oxide (LMR)” material, compared with cobalt-based battery materials, has been identified. Provided by Getty Image Bank.
Research results have been presented that increase the likelihood of actually applying next-generation battery materials that use inexpensive manganese instead of costly cobalt to large battery cells for electric vehicles.
Seoul National University announced on the 7th that a team led by Professor Jongwoo Lim in the Department of Chemistry and a joint research team from LG Energy Solution have identified the causes of gas generation and capacity fade that occur during the charge–discharge processes of lithium-manganese-rich layered oxide (LMR), and developed optimal operating conditions for large cells to control performance degradation. The research results were published in the international journal Nature Communications on the 2nd.
LMR is a next-generation cathode material that can reduce material costs by using low-cost manganese as the main raw material. It can increase storage capacity by utilizing not only transition metals such as nickel and manganese, but also oxygen within the material for energy storage.
The downside of LMR is that if the oxidized oxygen during charging does not sufficiently recover during discharging, it can cause oxygen release, structural damage, and gas generation. In large cells for electric vehicles, internal free space is limited, so these effects can lead to increased internal pressure and performance degradation.
The joint research team conducted a detailed analysis of the oxidation–reduction behavior of oxygen under different charge–discharge conditions. They found that how much the battery is charged and how deeply it is discharged is crucial for returning oxygen to its original state. Specifically, they discovered that the key variables governing oxygen recovery lie not only in the upper cutoff voltage during charging but also in the lower cutoff voltage during discharging.
When the upper cutoff voltage was lowered from 4.6 volts (V) to 4.3 V, the reduction rate of oxidized oxygen improved from 86% to 97%. When the lower cutoff voltage during discharge was reduced to 2.0 V, the oxygen was restored almost to its original state.
Based on this analysis, the LG Energy Solution research team redesigned the operating voltage window and the initial charge–discharge “activation process” conditions for 40 ampere-hour (Ah)-class large LMR cells. By applying a process that lowers the temperature during the activation stage, they suppressed gas generation in large cells.
Cells operated under the optimized conditions retained 92.2% of their initial energy even after 883 charge–discharge cycles. The results are considered to demonstrate the commercial viability of LMR materials at the large-cell level suitable for actual electric vehicle installation.
Professor Jongwoo Lim explained, “We confirmed that to ensure the long-term stability of LMR batteries, it is necessary to comprehensively consider discharge conditions as well as charge conditions.”
A representative from LG Energy Solution said, “This achievement shows that we can effectively suppress gas generation, which has been a major challenge for LMR batteries, and secure stable battery lifetime even in large cells,” adding, “It provides an important foundation for accelerating growth in the next-generation LMR battery market.”
doi.org/10.1038/s41467-026-76366-x
From left: Researcher Munsu Song of Seoul National University, Researcher Danwon Lee, and Professor Jongwoo Lim. Provided by Seoul National University.
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