Structural and electrochemical characteristics of nano-structured Li_0.53Na_0.03MnO_2 manganese oxide prepared by the sol-gel method

摘要

Li_0.53Na_0.03MnO_2 compound was prepared by ion exchange from Na_0.7MnO_2 which was synthesized by the sol-gel method using glycolic acid as a chelating agent. Powder X-ray diffraction and transmission electron microscopy (TEM) confirmed the structure of the as-prepared material resembled that of spinel with a high degree of disorder in the (111) planes. The material delivered a discharge capacity of 200 mAh g~(-1) after 50 cycles and showed excellent cyclability without undergoing the typical capacity fading exhibited by normal spinel mateial. It is speculated that the stacking disorder and small particle size of the prepared Li_0.53Na_0.03MnO_2 powder have contributed to prevent the symmetry-breaking transformation which is believed to be responsible for capacity fading.