Investigation Of Nanometer Oxide And Lithium Oxygen Batteries With Advanced Performances

With the rapid development of economy,the demand for usable energy is predicated to rise inexorably.Owing to the super-high calculated specific energy density of lithium-oxygen?Li-O2?battery,as high as 11,430 Wh kg-1,Li-O2 batteries currently enjoy great scientific attention.However,the development of Li-O2 battery remains at a very early stage,and numerous scientific challenges?such as poor rate capability,low round-trip efficiency,instability of electrolyte and especially short cycle life?still exist before the practical application of Li-O2 batteries.We put forward a kind of effective method for advanced nonaqueous Li-O2 batteries by using nanometer oxide.First of all,the highly mesoporous Cr₂O₃ nanotubes?Cr₂O₃-MNT?and composite oxide nanobelts,fabricated by an electrospinning technique combined with a heating method,are adopted the first time as catalyst for nonaqueous Li-O2 batteries.The surface area of Cr₂O₃-MNT and composite oxide nanobelts are 53.4 m2 g-1and 40.9 m2/g,respectively.Secondly,we then made a further investigation on specific capacity,rate capability and cycle stability of Li-O2 batteries with Cr₂O₃-MNT/SP,Cr₂O₃-NP/SP and SP cathode.An astonishing enhanced specific capacity of 8278.6 m Ah g-1 and excellent cyclic performance of 53 cycles can be achieved,demonstrating that the Cr₂O₃-MNT can both facilitate the formation and dissociation of Li2O2?The charging potential of Li-O2 battery by using the Cr₂O₃ nanotube as catalyst can be reduced to 3.78 V under a current density of 100 m Ag-1,which is among the lowest charging potentials reported for non-precious metal oxides.When Cr₂O₃-MNT/SP as oxygen electrode,the Li-O2 battery shows an astonishing enhanced rate capability,coulombic efficiency and capacity retention capability.In addition,we also investigated on specific capacity,overvoltage and cyclic voltammetry of Li-O2 batteries with mesoporous composite oxide nanobelts/SP,composite oxide nanobelts/SP and SP cathode.When mesoporous composite oxide nanobelts/SP as oxygen electrode,the Li-O2 battery shows an astonishing enhanced rate capability,as high as 7161.5 m Ah g-1,and reduced charging potential to 3.78 V under a current density of 50 m A g-1.