Integration strategy for facile fabrication of porous carbon coated Fe3O4 nanospindles with enhanced lithium storage

Abstract

Despite high capacities, the practical use of the Fe3O4-based anodes is still impeded because of poor cyclic performance caused by their large volumetric variation and pulverization during cycle. Aimed at the aforementioned problems, a composite of conformal porous carbon coated Fe3O4 nanospindles (Fe3O4 @PC) has been prepared by a well-designed integration strategy which not only simplifies the experimental steps but also restrains the severe aggregation of nano-sized Fe3O4 during carbon coating process. In particular, the superficially conformal porous carbon is demonstrated to not only accommodate the volumetric variation of the Fe3O4 nanospindles better with its flexible spongy structure but also provide fast and stable diffusion pathways for ions through its defect-enriched pores. With a combination of superficially conformal porous carbon coating, nano-sized one-dimensional structure and Fe–O–C chemical bonding, therefore, the as-prepared Fe3O4 @PC shows outstanding electrochemical behaviors in terms of high capacity, long lifespan and good rate performance, demonstrating 896.3 and 592.9 mA h g−1 after 400 cycles at 200 and 1000 mA g−1, respectively. Moreover, this work is expected to open up new avenues for designing and preparing other conformal porous carbon coated metal oxides for advanced LIB anodes or other applications.