To optimize the ORR performance of Co based cathode, the structure of carbon nanotube from DCI-Co precursor could be controlled through modulate synthetic parameters. 
DCI-Co
The optimized ORR catalyst Co@NCNT-700 exhibit larger BET area, higher content of Co-N x and graphitic N, which performance could be improved in further through Cu doping.  Furthermore, the high-performance zinc-air batteries was fabricated with the bimetal catalyst CuCo@NCNT-700 as an air electrode. 
Co@NCNT-700
Furthermore, the high-performance zinc-air batteries was fabricated with the bimetal catalyst CuCo@NCNT-700 as an air electrode. 
CuCo@NCNT-700