The research team investigated gas formation and capacity loss in the cells before adjusting their operating conditions and formation process. The findings have been published in the scientific journal Nature Communications.
LMR cathodes primarily rely on manganese and do not require cobalt. Alongside transition metals such as nickel and manganese, oxygen also participates in the energy-storage process. LG Energy Solution expects this combination to enable high energy density at potentially lower material costs. However, if oxygen oxidised during charging does not fully return to its original state during discharge, it can damage the cell structure and generate gases. In large-format cells, this can increase internal pressure and impair performance.
The research team therefore examined different charging and discharging voltages. According to LG Energy Solution, the recovery of oxidised oxygen increased from 86 to 97 per cent when the upper charge cut-off voltage was reduced from 4.6 to 4.3 volts. Lowering the discharge cut-off voltage from 3.0 to 2.0 volts also returned the oxygen almost completely to its original state.
LMR technology for large-format cells
Based on these findings, LG Energy Solution adjusted the voltage range and formation process for 40-Ah-class LMR cells. Among other measures, a lower temperature was used during formation to reduce gas formation. According to the battery manufacturer, the optimised cells retained 92.2 per cent of their original energy after 883 charge and discharge cycles.
