Synthesis and Electrochemical Performance of Carbon Nanotubes/Cobalt Manganese Oxides Composite Materials for Lithium Air Batteries

Carbon nanotabes/cobalt manganese oxides composites with different Co/Mn ratios were prepared by precipitation method. The as-prepared products were characterized by XRD, SEM, TEM, BET, FT-IR, discharge performance, charge performance and cycle profiles. The results show that the products are CNTs/Co3O4 and CNTs/Mn3O4 when Co/Mn ratios are 4:0 and 0:4, respectively, while CNTs/(Co, Mn)(Co, Mn)(2)O-4 is obtained at Co/Mn ratios of 3:1, 2:2 and 1:3. The products show high dispersion with oxides attaching to CNTs closely, and CNTs/Mn3O4 has the best morphology performance. With increasing content of Mn, the discharge performance improves. CNTs/Mn3O4 has the highest discharge voltage of 2.92 V. For charge processes, the product with higher content of Co reveals better charge properties. The lowest voltage is about 3.8 V. Meanwhile, the product with Co/Mn ratio of 3:1 has a minor charge-discharge voltage difference(Delta V) of 1.05 V, which still keeps excellent electrochemical performance after 5 charge-discharge cycles.