A hybrid-type Li-air battery based on a polypyrrole/carbon nanocomposite catalyst as the cathode

Eco-friendly and cost-effective materials with high catalytic activities are of immense interest for metal-air batteries because of their relatively high round-trip efficiencies. Herein, we have successfully demonstrated the use of a polypyrrole/carbon nanocomposite (PPyC) coated on heat-treated carbon felt by a simple dipping method as an electrocatalyst electrode. The PPyC nanocomposite exhibited higher electrocatalytic activity than vulcan carbon black, which was ascribed to its high surface area (807.37 m(2) g(-1)) and good electrical conductivity (10-50 S cm (1))Furthermore, we also described a PPyC-based, hybrid-type Li-air battery with a Li-metal anode that exhibits excellent round-trip efficiency (92.9%) and cycling performance over 20 cycles. To the best of our knowledge, this is the first report on the electrocatalytic activity of a PPyC nanocomposite catalyst and a PPyC-based, rechargeable, hybrid-type Li-air battery.