Three-Dimensional Nanofibrous Air Electrode Assembled With Carbon Nanotubes-Bridged Hollow Fe₂O₃ Nanoparticles for High-Performance Lithium–Oxygen Batteries

Lithium–oxygen batteries have been considered as one of the most viable energy source options for electric vehicles due to their high energy density. However, they are still faced with technical challenges, such as low round-trip efficiency and short cycle life, which mainly originate from the cathode part of the battery. In this work, we designed a three-dimensional nanofibrous air electrode consisted of hierarchically structured carbon nanotube-bridged hollow Fe 2 O 3 nanoparticles (H-Fe 2 O 3 /CNT NFs). Composite nanofibers consisted of hollow Fe 2 O 3 NPs anchored by multiple CNTs offered enhanced catalytic sites (interconnected hollow Fe 2 O 3 NPs) and fast charge-transport highway (bridged CNTs) for facile formation and decomposition of Li 2 O 2, leading to outstanding cell performance: (1) Swagelok cell exhibited highly reversible cycling characteristics for 250 cycles with a fixed capacity of 1000 mAh g –1 at a current density of 500 mA g –1 . (2) A module composed of two pouch-type cells stably powered an light-emitting diode lamp operated at 5.0 V.