Synthesis and electrochemical characterization of Si-Mn alloy anode materials for high energy lithium secondary batteries.

The Si-Mn alloys as anode active materials were prepared by mechanical milling and calcination at three different temperatures like 600, 700, and 800 degrees C. The alloys were characterized by X-ray diffraction, field emission-scanning electron microscopy, field emission-transmission electron microscopy, and electrochemical cycling within a range of 2.5 V to 0.01 V versus Li/Li+. We found that the Si-Mn alloy calcined at 800 degrees C exhibited (i) an enhanced reversible capacity during the intercalation and de-intercalation process and (ii) a reduction in fading capacity characteristic due to modified structural and interfacial properties. Increasing the calcination temperature could improve the electrochemical performance of these materials, especially at 800 degrees C. Hence this alloy possibly suited to apply for lithium rechargeable batteries. The reversible capability after fourth cycling increases in the range of 95% to nearly 99% coulombic efficiency during the following intercalation and de-intercalation process. The Si-Mn alloy has the potential to be suitable for use as an anode active material in lithium rechargeable batteries.