Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6473264 | Electrochimica Acta | 2016 | 7 Pages |
â¢Pomegranate-like Silicon/Nitrogen-doped graphene microspheres have been prepared.â¢The N-doped graphene provides enormous Li+ diffusion channels and active sites.â¢The wrapping graphene significantly enhances the conductivity of Si-based anode.â¢The PSNGM anode exhibits excellent electrochemical performance with high capacity.
Herein, pomegranate-like Silicon/Nitrogen-doped graphene microspheres (PSNGM) constructed by individual Si nanoparticle core wrapped by flexible nitrogen-doped reduced graphene oxide nanosheets (NG) have been synthesized through a facile and industrially large-scale spray drying approach. The PSNGM anode delivers excellent electrochemical performance: the reversible specific capacity at 100 mA gâ1 remains as large as 1141.6 mAh gâ1 after 150 cycles, with a high capacity retention of 96.1% from 2nd to 150th cycle; the capacity at 100 mA gâ1 can recover back to â¼1340 mAh gâ1 even after suffering a high current density of 5000 mA gâ1. The excellent performance is attributed to the unique pomegranate-like structure, nanoparticlization of Si and nitrogen doping of graphene: the pomegranate-like skeleton forms a highly conductive network, in which each Si nanoparticle is homogenously wrapped by flexible and conductive N-doped graphene nanosheets; flexible porous pomegranate-like structure can effectively accommodate the large volume variation during cycling; the N-doped graphene matrix guarantees its high conductivity for better electron and ion kinetics. The presented spray drying strategy is facile, low-cost and effective for large-scale industrial production of Si/graphene composite anode, and it can also be extended to fabricating other high-capacity electrode materials with low conductivities and large volume expansion.
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