Highlights A new and facile method to synthesize N, F-codoped microporous carbon nanofiber (N, F-MCF) electrocatalysts via electrospinning, hydrothermal process, and thermal treatment. Polyvinylidene fluoride is applied as a fluorine source in oxygen reduction reaction (ORR) catalysis for the first time in literature. N, F-MCFs exhibit distinguished electrocatalytic activity, stability, and methanol tolerance for ORR in alkaline media. Electronic supplementary material The online version of this article (10.1007/s40820-019-0240-x) contains supplementary material, which is available to authorized users.