α-MnO_2 hollow clews for rechargeable Li-air batteries with improved cyclability

Lithium-air(Li-air) batteries have attracted worldwide attention due to their high energy density(11140 Wh kg-1) comparable to gasoline.In this work,we have synthesized the α-MnO2 hollow clews via a simple method and characterized them by X-ray diffraction and scanning electron microscope.Interestingly,cycle performance of Li-air batteries is improved greatly when using the α-MnO2 hollow clews as the catalyst.The first discharge capacity is 596 mAh g-1,and the charge capacity is 590 mAh g-1 at the current density of 0.1 mA cm-2 between 2.0 and 4.2 V using the Vulcan XC-72 as the carbon material.Additionally,by re-assembling new batteries with the used lithium foil,separators and cathode separately,we find that the cathode is the key role to end the Li-air battery life.

Lithium-air （Li-air） batteries have attracted worldwide attention due to their high energy density （11140 Wh kg 1） comparable to gasoline. In this work, we have synthesized the α-MnO2 hollow clews via a simple method and characterized them by X-ray dif- fraction and scanning electron microscope. Interestingly, cycle performance of Li-air batteries is improved greatly when using the α-MnO2 hollow clews as the catalyst. The first discharge capacity is 596 mAh g -1, and the charge capacity is 590 mAh g t at the current density of 0.1 mA cm 2 between 2.0 and 4.2 V using the Vulcan XC-72 as the carbon material. Additionally, by re- assembling new batteries with the used lithium foil, separators and cathode separately, we find that the cathode is the key role to end the Li-air battery life.