LAUSR

Despite remarkable development in high capacity iron oxide-based electrodes for lithium-ion batteries (LIBs), the low mass loading and poor areal capacity still impede their practical applications. In this report, novel FeOx nanoarrays were directly constructed on three-dimensional (3D) copper foam current collector (denoted as CF@FeOx NAs) via facile hydrothermal growth followed by a postannealing process. The nanoarrays were stacked by numerous FeOx porous nanoblocks, exhibiting a unique hierarchical structure. The loading density of FeOx in the CF@FeOx NAs reached 2.5 mg cm–2 owing to the hierarchical structure of the novel 3D nanoarray electrode. When tested as an anode for LIBs, the 3D integrated electrode delivered high areal capacities of 3.33 and 2.61 mAh cm–2 at 0.25 and 1.25 mA cm–2, respectively. A high areal capacity of 2.12 mAh cm–2 was retained at 2.5 mA cm–2 after 500 cycles, which is the best electrochemical performance in terms of areal capacity for the iron oxide-based electrodes reporte...