Paramecium‐Like Iron Oxide Nanotubes as a Cost‐Efficient Catalyst for Nonaqueous Lithium‐Oxygen Batteries

Fe2O3‐based catalysts have been developed to achieve a low overpotential and a long cycle life for nonaqueous Li–O2batteries. However, previous studies focus mainly on nanoparticles or nanoflakes, which have shown limited improvements for battery performance. Here, paramecium‐like Fe2O3nanotubes (FNTs) are synthesized by a hard‐template method and applied as the catalyst in a nonaqueous Li–O2battery. The large specific surface area and unique tubular structure of the FNTs allow the nonaqueous Li–O2battery to deliver a high capacity of 6000 mAh g−1at a discharge current density of 500 mA g−1with a low discharge and charge overpotential of approximately 0.19 and 0.85 V, respectively. Moreover, the battery can be operated at a discharge current density as high as 1000 mA g−1with a capacity of 3940 mAh g−1and demonstrates an excellent rate capability. The prepared catalyst enables the battery to maintain the discharge capacity and Coulombic efficiency without any degradation for 150 cycles at 500 mA g−1with a fixed capacity of 500 mAh g−1, which is 110 more cycles than the battery without the catalyst. Cost‐efficient catalyst for Li–O2batteries: Paramecium‐like Fe2O3nanotubes are synthesized using a hard‐template method. As a catalyst in a nonaqueous Li–O2battery it can deliver a very high capacity. The discharge capacity and the Coulombic efficiency can be maintained at a lower fixed discharge capacity without any degradation for 150 cycles. SP=Super P.