Improved cathode performance and relaxation properties of LiMn2O4 prepared by optimized ball-milling with single-step sintering

LiMn2O4 has been prepared by means of high-energy ball-milling of Li2CO3 and MnCO3 followed by one-pot sintering. Milling at 800 rpm for 4 h with sintering at 700 degrees C for 12 h leads the enhanced cathode performance as 123.5 mAh g(-1) of initial discharge capacity under 1C charge-discharge rate, retaining 95.1 and 91.6% of capacity after 100 and 200 cycles, respectively. Mechanochemical reaction facilitates the sintering reaction to form the favorable microstructure homogeneously without second phase. Relaxation analysis showed that, at the charging around x = 0.2 for LixMn2O4, the sample prepared by optimal milling time varies mainly lithium concentration in Li-rich phase, while excessively milled sample alter the molar ratio of Li-rich and Li-lean phases. This indicates that optimal milling time allows the sample to undergo the less structural change at the charging, which enables the improved cycle performance. (C) 2021 The Ceramic Society of Japan. All rights reserved.