Preparation and properties of manganese oxide/carbon composites by reduction of potassium permanganate with acetylene black

Amorphous manganese oxide/carbon composites were synthesized by directly reducing potassium permanganate with acetylene black (AB) as a cheap reducing agent. A reaction is postulated and confirmed by checking the evolved CO2 gas and other species such as CO32- and HCO3- left in the mother liquor. All the composites were characterized by scanning electron micrograph, X-ray diffraction, and thermogravimetric/diffenential thermal analysis techniques. The electrochemical performances of the composites were also investigated and one composition delivered a discharge capacity as high as 231 mAh g(-1) (1.14 Li/Mn) at a current density of 40 mA g(-1) and its electrochemical performance at high rate was excellent. All results suggested that the reaction is suitable for preparing a composite cathode material and these composite materials could be developed as a potential cathode material for rechargeable Li batteries with high power. The intercrystalline water, affecting the behavior of our composites, was also discussed. (c) 2006 The Electrochemical Society.