MnO_2 Nanorods Prepared by Redox Reaction as Cathodes in Lithium Batteries

摘要

We report the structural and electrochemical of the a- and β-MnO_2 phases synthesized by redox reaction of ammonium persulphate with manganese sulphate and manganese nitrate. A single phase of a-MnO_2 was observed or the sample prepared from manganese sulphate, while β-MnO_2 phase was obtained from manganese nitrate. Characteristic bands of hollandite and rutile phase were observed by FTIR. Nanorods structures were observed by images of transmission electron microscopy for both samples. Good electrochemical performance was observed for β-MnO_2, which yields a specific discharge capacity of 180 and 130 mAh g~(-1) in the first and 45~(th) cycle respectively. The specific discharge capacity of α-MnO_2 is ca. 210 mAh g~(-1) at first cycle that decreases to 115 mAh g~(-1) in the 45~(th) cycle.