A twisted carbonaceous nanotube as the air-electrode for flexible Zn-Air batteries.

Exploring electrocatalysts with high-efficiency oxygen reduction reaction (ORR) is significant for practical applications of fuel cells and metal-air batteries. In this work, a twisted core@shell material has been prepared with helical polypyrrole nanotubes (HPPys) as the core and coordination polymers (CPs) as the shell. After the pyrolysis process, a dense twisted carbon layer was formed by the reaction of CP and HPPy at its interface under Ar. The derived twisted carbonaceous nanotube exhibits good performance in both electrocatalytic ORR and OER. When used as the air-electrode in a flexible Zn-air battery, the battery shows good performance and stability.