Revisiting the origin of cycling enhanced capacity of Fe3O4 based nanostructured electrode for lithium ion batteries

• Published in: Nano energy 2017-11, Vol.41, p.426-433
• Main Authors: Huang, Yuan, Xu, Zihan, Mai, Jiangquan, Lau, Tsz-Ki, Lu, Xinhui, Hsu, Yao-Jane, Chen, Yongsheng, Lee, Alex Chinghuan, Hou, Yanglong, Meng, Ying Shirley, Li, Quan
• Format: Article
• Language: English
• Subjects: Cycling performance; Fe3O4 nanoparticles; Graphene foam; Lithium ion batteries
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2017.10.001

We identify that reversible formation/decomposition of lithium oxide, pulverization of Fe3O4 nanoparticles, and electrolyte reactions, are contributors to the enhanced capacity observed in the Fe3O4 electrode upon long cycling. Introducing three-dimensional graphene foam to form a composite with Fe3O4 nanoparticles largely increases the capacity (~ 1220mAhg−1 vs. ~ 690mAhg−1) and promotes the cycling induced capacity enhancement (an earlier capacity rise and a faster rising rate) of the Fe3O4 electrode. Together with Fe3O4 nanoparticles, the presence of graphene effectively promotes the electrolyte reactions and reversible formation/decomposition of lithium oxide. At the same time, activation of GF also occurs in the presence of Fe3O4 nanoparticles, further increases the capacity of the nanocomposite. [Display omitted] •Pulverization of Fe3O4 contributes to enhanced capacity upon long cycling.•The electrolyte reactions also contribute to enhanced capacity upon long cycling.•Reversible formation/decomposition of lithium oxide serves as another contributor.•Introducing graphene to Fe3O4 results in enhanced capacity and cycling performance.•Electrochemical activation of graphene occurs in the presence of Fe3O4.