Ultrahigh cycling stability and rate capability of ZnFe2O4@graphene hybrid anode prepared through a facile syn-graphenization strategy

Abstract

A ZnFe₂O₄–reduced graphene oxide (ZnFe₂O₄–RGO) hybrid has been successfully synthesized through a facile syn-graphenization strategy. In this preparation procedure, N₂H₄·H₂O works as both a base source and a reductant, and the reduction of graphene oxide (GO) into RGO is accompanied by the formation of ZnFe₂O₄. In comparison with bare ZnFe₂O₄, the ZnFe₂O₄–RGO hybrid shows ultrahigh cycling stability and rate capability as an anode material for lithium ion batteries. The cycling capacity of the ZnFe₂O₄–RGO hybrid at the 100th cycle is considerably enhanced to 1025 mA h g⁻¹, compared with only 166 mA h g⁻¹ for bare ZnFe₂O₄. The rate performance can also be significantly improved to 800 mA h g⁻¹ at the current density of 1000 mA g⁻¹. The much better cycling stability and rate capability can be largely attributed to the well dispersed conductive RGO and the tight binding between ZnFe₂O₄ and RGO, which is a benefit of the subtle syn-graphenization strategy. In addition, the effects of RGO content on the electrochemical performance are presented.