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

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 (MnOx10-PCN) show superior rate performance over PCN. MnOx10-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 MnOx10-PCN. SEM results indicate that both MnOx10-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 MnOx10-PCN and PCN. BET analysis reveals that pore properties of MnOx10-PCN are very near to that of CMP. These unique features ensure MnOx10-PCN possesses high reversible capacity, excellent rate performance, and long cycling life. MnOx10-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.