Metal oxide-embedded porous carbon nanoparticles as high-performance anode materials for lithium ion batteries

摘要

Conjugated microporous polymer (CMP) was used as a precursor to fabricate porous carbon nanoparticles (PCNs) embedded with different metal oxides (NiOx, CoOx, and MnOx). Rate performance tests indicate that 10% MnOx embedded PCNs (MnO(x)10-PCN) show superior rate performance over PCN. MnO(x)10-PCN and PCN were further investigated by XRD, XPS, TG, SEM, TEM, FT-IR, BET, cyclic voltammetry, and galvanostatic discharge-charge test. XRD and XPS results reveal that MnO and MnO2 phase co-exist in the MnO(x)10-PCN. SEM results indicate that both MnO(x)10-PCN and PCN are spherical particles with a size ranging from 20 to 50 nm. TEM results imply that MnOx nanoparticles are incorporated inside some porous carbon nanoparticles. FT-IR results indicate some residuary benzene rings remain in the MnO(x)10-PCN and PCN. BET analysis reveals that pore properties of MnO(x)10-PCN are very near to that of CMP. These unique features ensure MnO(x)10-PCN possesses high reversible capacity, excellent rate performance, and long cycling life. MnO(x)10-PCN delivers an initial reversible capacity of 986 mAh g(-1) at 0.2 C. In addition, the capacity cycled at 2 C for 700 cycles is even higher than its original capacity.