LG Energy Solution and Seoul National University have identified a promising way to improve the stability and durability of next-generation lithium manganese-rich (LMR) batteries, potentially bringing the technology closer to use in large-format electric vehicle battery cells.
The research, conducted with Professor Jongwoo Lim and his team in the Department of Chemistry at Seoul National University, focuses on one of the biggest challenges facing LMR batteries: gas generation and capacity degradation during repeated charging and discharging.
The findings were published in Nature Communications and demonstrate that carefully optimized charging, discharging and battery formation conditions can significantly improve the performance of large-format LMR cells.
LMR Batteries Could Reduce EV Battery Costs
Lithium manganese-rich cathode materials are attracting attention as a potential alternative for future EV batteries because they can rely heavily on manganese, a relatively low-cost material, while reducing or eliminating the need for cobalt.
LMR cathodes can also achieve high energy density by storing energy through reactions involving transition metals such as nickel and manganese, as well as oxygen within the cathode structure.
However, oxygen activity creates a major technical challenge.
During charging, some oxygen in the cathode becomes oxidized. If that oxygen does not fully return to its original state during discharge, it can contribute to structural damage inside the battery and generate gas.
That problem becomes particularly important in large-format EV cells. With less internal space available to accommodate gas, pressure can build inside the cell, potentially reducing performance, durability and safety.
Charging and Discharging Both Matter
The LG Energy Solution and Seoul National University research team studied how oxygen redox behavior changes under different charging and discharging conditions.
The researchers found that oxygen recovery is strongly influenced by both the upper charging voltage and the discharge cutoff voltage. This is important because battery degradation cannot be addressed by optimizing charging conditions alone.
In testing, reducing the upper charging voltage from 4.6 volts to 4.3 volts increased the recovery of oxidized oxygen from 86% to 97%.
The researchers also found that reducing the discharge cutoff voltage from the conventional 3.0 volts to 2.0 volts allowed the oxygen to recover to nearly its original state.
These findings enabled the team to redesign the operating voltage range and formation process for large-format LMR battery cells.
40 Ah LMR Cell Shows Strong Cycle Life
Using the optimized operating conditions, LG Energy Solution researchers developed 40 Ah-class large-format LMR cells.
The team also introduced a lower-temperature formation process designed to reduce gas generation associated with large-format cells.
The resulting cells retained 92.2% of their initial energy after 883 charge-discharge cycles.
That result is significant because cycle-life and gas-generation issues have been among the main barriers to expanding LMR technology from smaller battery formats to the larger cells required for electric vehicles.
Professor Jongwoo Lim said the study identified the causes of LMR battery degradation from the perspective of oxygen reversibility and showed that battery stability can be improved through electrochemical protocol design.
The research also highlights the importance of considering both charging and discharging conditions when developing long-lasting LMR batteries.
A Potential Step Toward Lower-Cost EV Batteries
The results could strengthen the case for LMR cathodes in future electric vehicle batteries. Lower reliance on expensive cobalt, combined with the potential for high energy density, makes manganese-rich battery chemistry an attractive area of development as automakers and battery manufacturers look for ways to reduce costs.
More importantly, the research suggests that some of the stability problems associated with LMR batteries can be addressed through battery operating strategies and cell formation processes rather than requiring a completely different material design.
For EV manufacturers, that could make large-format LMR cells more practical for future battery packs.
LG Energy Solution said the research addresses a key obstacle facing LMR batteries by demonstrating that stable battery life can be achieved in large-format cells while effectively suppressing gas generation.
If the technology continues to progress toward commercial production, LMR batteries could become an important option for the next generation of electric vehicles, particularly as the industry looks for lower-cost battery chemistries without giving up energy density and durability.
