The electrochemical characterization and kinetic investigation of sub-micron Bi2Fe4O9 as possible anode of advanced lithium-ion batteries

Abstract

Research in anode materials of Li-ion batteries has demonstrated an effective strategy to improve its capacity by the combination of abundant Fe as a redox center and Bi as an alloying center, which integrates the merits of Bi2O3 and Fe2O3 anodes. In this work, a novel lithium storage material Bi2Fe4O9 has been synthesized via a facile hydrothermal method. A time-dependent experiment at 160 ℃ displays that the proper reaction time is 12 h for obtaining the pure Bi2Fe4O9 sub-micron particles (SM-BFO). When applied as anode of Li-half battery, the as-prepared SM-BFO delivers a high first discharge capacity (1038.4 mAh g−1) at 0.2 A g−1, excellent cyclability (459.6 mAh g−1 after 500 cycles), good rates capability (138.9 mAh g−1 even at 5.0 A g−1), low active energy (50 kJ mol−1) and fast ion diffusion coefficient (6.9◊10−12 cm2 s−1) compared to that of the bulk counter, owing to the shorter diffusion distance. The results illustrate a great potential in advanced Li-ion batteries.