Effect of Polypyrrole Coating on Li Powder Anode for Lithium-Sulfur Secondary Batteries

Polyppyrole (PPy)-coated Li powders were prepared via planetary milling techniques and used as an anode material for rechargeable Lithium-Sulfur (Li-S) batteries. The PPy-coated Li powder anode was analyzed by scanning electron microscopy (SEM, transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). The PPy coating on the Li powder provided the protection layer to inhibit the electrochemical reaction between the Li powder anode and dissolved lithium polysulfide anions in the electrolyte, which minimized the overcharge and reduced the capacity fading. The charge-discharge process of the PPy-coated Li powder anode cell showed a capacity of 878 will g(-1) at 1st cycle and 500 mAh g(-1) after 50th cycles.