Defect-Enriched Iron Oxide from Industrial Waste for Lithium Oxygen Batteries with High Economic Efficiency and Industrial Feasibility

Abstract

Different phase iron oxide cathode materials for the lithium–oxygen battery were synthesized by taking acid-pickled iron oxide red industrial waste as a raw resource. Based on the high economic efficiency and high industrial feasibility of the process, it can realize a circular economy that not only develops a potential high-performance cathode material from industrial waste, thereby increasing economic efficiency, but also makes a significant contribution to environmental protection and increases the value of pickled iron oxide red. The obtained Fe3O4 material shows good electrochemical properties when employed as the cathode material for the lithium–oxygen battery. It delivered the discharge capacity up to 11 751 mA h g–1 at the current density of 100 mA g–1, 97 cycles with the capacity fixed at 500 mA h g–1, and 58 cycles with a reversible capacity of 1000 mA h g–1. This enhanced electrochemical performance is attributed to a combination of an abundant oxygen vacancy effect on the surface and Fe mix-valence state effects.