h i g h l i g h t s g r a p h i c a l a b s t r a c t Reported is graphene nanoplatelets delivered by grinding graphite in BMIM-PF 6. Contrasted is structure, composition and ORR after varied grinding durations. Grinding decreases the nanoplatelet size, while increasing surface defects. Prolonging the graphite grinding before pyrolysis increases nitrogen incorporation. ORR catalysis is enhanced by prolonged grinding, with higher stability than Pt/C.