Graphene　is　a　type　of　promising　electrode　material　for　high-energy　and　high-power　density　supercapacitors,　but　its　electrochemical　performance　is　greatly　limited　by　the　restacking　problem.　In　this　work,　we　reported　a　facile　approach　to　synthesis　graphene　with　chemically　bonded　vanadium　oxide　(VOx)　nanoparticles　and　demonstrated　that　chemically-bonded　VOx　nanoparticles　can　effectively　prevent　the　graphene　sheets　from　restacking　and　hence　improve　the　electrochemical　performance.　The　capacitance　of　VOx-bonded　graphene　increases　to　272　F/g　compared　to　183　F/g　of　pristine　graphene　in　1　M　H3PO4　aqueous　electrolyte　at　2　A/g.　The　VOx-bonded　graphene　also　showed　improved　rate　capability　in　both　H3PO4　and　ionic　liquid　electrolytes.　The　capacitance　retention　increases　to　54.5%　from　28.5%　at　100　A/g　(compare　to　2　A/g)　in　H3PO4　and　increases　to　65.1%　from　46.3%　at　2　A/g　(compare　to　0.2　A/g)　in　neat　ionic　liquid.　A　high　energy　density　of　84.4　Wh/kg　is　obtained　within　the　voltage　window　of　4　V　in　ionic　liquid.　Even　at　a　high-power　density　of　1000　W/kg,　the　VOx-bonded　graphene　shows　a　high　energy　density　of　47.3　Wh/kg.　©　2020