▎ 摘　　要

Carbon dots have been recognized as one of the most promising candidates for the oxygen reduction reaction (ORR) in alkaline media. However, the desired ORR performance in metal-air batteries is often limited by the moderate electrocatalytic activity and the lack of a method to realize good dispersion. To address these issues, herein a biomass-deriving method is reported to achieve the in situ phosphorus doping (P-doping) of carbon dots and their simultaneous decoration onto graphene matrix. The resultant product, namely P-doped carbon dot/graphene (P-CD/G) nanocomposites, can reach an ultrahigh P-doping level for carbon nanomaterials. The P-CD/G nanocomposites are found to exhibit excellent ORR activity, which is highly comparable to the commercial Pt/C catalysts. When used as the cathode materials for a primary liquid Al-air battery, the device shows an impressive power density of 157.3 mW cm(-2) (comparing to 151.5 mW cm(-2) of a similar Pt/C battery). Finally, an all-solid-state flexible Al-air battery is designed and fabricated based on our new nanocomposites. The device exhibits a stable discharge voltage of approximate to 1.2 V upon different bending states. This study introduces a unique biomass-derived material system to replace the noble metal catalysts for future portable and wearable electronic devices.