Effect of PEDOT:PSS Coating on Manganese Oxide Nanowires for Lithium Ion Battery Anodes

Transition metal oxides have been considered as promising lithium storage materials that undergo a conversion reaction, exhibiting high specific capacity. However, capacity fading during cycling is the most serious obstacle for their commercialization. In order to overcome this, we have added PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) to Mn₂O₃ nanowires. PEDOT:PSS was successfully coated onto Mn₂O₃ nanowires while maintaining the structure of Mn₂O₃. The coating of PEDOT:PSS reduced the resistance of the surface and protected the surface electron channels from the pulverization effect of the charge-discharge operation. α-Mn₂O₃/PEDOT:PSS showed excellent cyclability with a reversible capacity of 1450 mAh g^-1 after 200 cycles at a current density of 100 mA g^-1. An increase in capacity was observed with continuous cycling, which may be attributed to further oxidation of the manganese species and a reversible reaction of the gel-like polymer on the manganese surface. The results demonstrate that PEDOT:PSS enhances the electrochemical activity by providing electron channels and prevents pulverization caused by the charge and discharge process.