Synthesis and electrochemical properties of sulfur doped-Li_xMnO_(2-y)S_y materials for lithium secondary batteries

摘要

Sulfur doped lithium manganese oxides (Li_xMnO_(2-y)S_y) were prepared by ion exchange of sodium for lithium in Ma_xMnO_(2-y)S_y precursors obtained by a sol-gel method. These materials had the nano-crystallite size, which was composed of grain size of about 100-200 nm. Especially, Li_(0.56)MnO_(1.98)S_(0.02) delivered the initial discharge capacity of 170 mAh g~(-1) and gradually increased the discharge capacity of 220 mAh g~(-1) until 50 cycles. moreover, it showed an excellent cycling behavior, although its original structure transformed into the spinel phase during cycling.