Lithium storage performance of coralline-like FeMnO3 anode materials prepared by a facile chemical co-precipitation method

Abstract

Mixed transition metal oxides have attracted much attention as anode materials for lithium-ion batteries because of their high theoretical capacity, low cost, and rich redox reaction. In this work, coralline-like FeMnO3 anode materials are synthesized by a facile co-precipitation method and subsequent sintering in air. The influences of sintering temperature on the microstructure and electrochemical performance of the samples are investigated. The results demonstrated that with the increase of sintering temperature, the phase structure of the products changes from FeMnO3/Fe2O3/Mn3O4 composites at 600 °C to pure phase FeMnO3 at 1000 °C, accompanied with the size of the primary particle increasing from tens of nanometers to hundreds of nanometers. Discharge/charge performance tests indicated that the sample sintered at 600 °C presents the biggest fluctuation of capacity during cycling, while the sample sintered at 1000 °C gives a rather flat capacity during cycling; moreover, the pure phase FeMnO3 at 1000 °C possesses the best rate capability among the three samples. For example, the pure phase FeMnO3 sintered at 1000 °C delivers a specific capacity of 585 mA h g−1 after 290 cycles at the current of 1000 mA g−1; even at the high current density of 5 A g−1, the capacity still retained at 397 mA h g−1. Charge storage mechanism analysis revealed that the pure phase FeMnO3 sintered at 1000 °C shows obvious pseudocapacitive behavior during the discharge/charge process, which partly account for its superior cycling performance and high-rate capability.