Holistic Optimization of Li- and Mn-Rich Cathodes from Precursor Coprecipitation to Mechanochemical Calcination

Abstract

Li- and Mn-rich layered oxide (LMR) cathodes offer high capacity through both transition metal and oxygen redox but remain limited by voltage/energy fade and sluggish high-rate kinetics. Here, we develop a holistic process–structure–performance optimization strategy for enhanced LMR cathodes by controlling conditions for coprecipitation, calcination, and mechanochemical treatment. First, ammonia concentration and pH were tuned to regulate complexation and precipitation kinetics, yielding precursors with improved particle-size uniformity and structural crystallinity. Second, calcination temperature was optimized to balance layered crystallinity against grain coarsening and strain accumulation, identifying 900 °C as the structural optimum. Third, ball milling the precursor with a lithium source further reduced the primary particle size, significantly enhancing the rate capability. These results evidence the effectiveness of the integrated optimization of precursor chemistry, calcination control, and mechanochemical treatment for improved Li+ insertion kinetics toward high-power LMR cathodes.