Synthetic strategies to improve the performance of manganese oxide based layered and spinel materials for electrochemical energy storage

Abstract

This work studied the manganese oxide based nanostructures for enhanced performance (power and energy densities) as electrode materials in lithium ion batteries (LIBs) and electrochemical capacitors (ECs). The high energy LiMn1.5Ni0.5O4 (LMN), the solid solution layered Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC) and Al doped Li1.2Mn0.52Ni0.13Co0.13Al0.02O2 counterpart (LMNCA) cathode materials for LIB were synthesized by a modified Pechini one-step powder forming, microwave-assisted method. This novel synthesis route also included an intermediate step where samples were treated with microwave irradiation for a short period (~ 20 min) prior to the extended period (~ 8 hr) of annealing (~ 700 – 800 °C). It is proved, for the first time, that microwave irradiation is capable of tuning the Mn3+ content of the LMN spinel for enhanced electrochemical performance (i.e., high capacity, high capacity retention, excellent rate capability, and fast Li+ insertion/extraction kinetics).