Full Protection for Graphene‐Incorporated Micro‐/Nanocomposites Containing Ultra‐small Active Nanoparticles: the Best Li‐Storage Properties

Publisher： John Wiley & Sons Inc

E-ISSN： 1521-4117|32|11|1020-1027

ISSN： 0934-0866

Source： PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION (ELECTRONIC), Vol.32, Iss.11, 2015-11, pp. : 1020-1027

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

In recent years, graphene‐incorporated micro‐/nanocomposites represent one of the hottest developing directions for the composite materials. However, a large number of active nanoparticles (NPs) are still in the unprotected state in most constructed graphene‐containing designs, which will seriously impair the effects of the graphene additives. Here, a fully protected Fe3O4‐based micro‐/nanocomposite (G/Fe3O4@C) is rationally developed by carbon‐boxing the common graphene/Fe3O4 microparticulates (G/Fe3O4). The processes and results of full protection are tracked in detail and characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, and nitrogen absorption–desorption isotherms, as well as scanning and transition electron microscopy. When used as the anode for lithium‐ion batteries, the fully protected G/Fe3O4@C exhibits the best lithium‐storage properties in terms of the highest rate capabilities and the longest cycle life compared to the common G/Fe3O4 composites and commercial Fe3O4 products. These much improved properties are mainly attributed to its novel structural features including complete protection of active Fe3O4 nanoparticles by the surface carbon box, a robust conductive network composed of nitrogen‐doped graphene nanosheets, ultra‐small Fe3O4 NPs of 4–5 nm, abundant mesopores to accommodate the volume variation during cycling, and micrometer‐sized secondary particles.