Cobalt　hydroxide　is　expecting　electrode　material　for　high-performance　supercapacitors,　however,　it　is　still　a　challenge　to　improve　its　lack　of　transmission　track　and　active　sites.　An　effective　method　to　improve　the　electrochemistry　performance　of　cobalt　hydroxide　is　to　couple　it　with　graphene　quantum　dots.　Herein,　we　report　the　preparation　of　Cobalt　hydroxide/N　doped　graphene　quantum　dots　(Co(OH)2/NQDs)　composites　and　study　the　electrochemistry　performance　of　Co(OH)2/NQDs　composites　as　supercapacitors　electrode　materials.　Benefit　from　the　strong　coupling　between　NQDs　and　Co(OH)2　creates　new　electron　transfer　channels　(Co-N).　The　hybrid　supercapacitor　device　based　on　Co(OH)2/NQDs　composite　and　GA　shows　a　high　energy　density　of　about　33.6　Wh　kg−1　at　a　power　density　of　800　Wk　g−1,　and　it　retains　about　137%　specific　capacitances　after　8000　cycle　test.　Due　to　the　negative　potential　of　NQDS,　it　can　generate　an　electrostatic　reaction　with　Co2+,　which　can　stabilize　cobalt　hydroxide　after　long　cycles.　©　2022