Although　studies　have　been　done　on　nitrogen　doped　carbon　materials　as　lithium-oxygen　(Li-O-2)　battery　cathodes,　few　of　them　focus　on　the　binder-free　electrode　structure,　although　they　have　been　proved　to　bring　improved　performance.　To　fill　this　gap　this　work　not　only　studies　the　nitrogen　doped　binder-free　carbon　cathode　but　also　determines　the　performance　of　these　cathodes　with　different　levels　of　nitrogen　doping.　To　make　binder-free　electrodes,　these　CNTs　and　N-CNTs　were　synthesized　on　nickel　foam　by　a　floating　catalyst　chemical　vapor　deposition　method.　The　study　found　that　the　electrochemical　performance　of　binder-free　N-CNT　cathodes　in　Li-O-2　batteries　improves　as　the　level　of　nitrogen　doping　increases.　To　further　study　the　reason　why　the　electrodes　with　higher　nitrogen　amounts　deliver　better　electrochemical　properties,　the　morphology　of　discharge　products　on　the　different　nanotubes　are　detected　by　scanning　electron　microscopy　(SEM).　The　scan　shows　that　the　distribution　of　discharge　products　on　the　surface　of　CNTs　become　more　and　more　uniform　as　the　level　of　nitrogen　doping　increases　and　the　discharge　capacity　and　cycle　performance　are　subsequently　improved.　Therefore,　these　binder-free　N-CNT　electrodes　could　be　further　explored　as　high　capacity　cathode　materials　for　Li-O-2　battery　applications.