Confined oriented growth of FeSe 2 on a porous graphene film as a binder-free anode for high-rate lithium-ion batteries

• Published in: Materials advances Vol. 4; no. 18; pp. 4190 - 4196
• Main Authors: Zhang, Xiaoting, Diao, Jiaxiu, Qiao, Jinghao, Wen, Yuhui, Zhang, Hongkun, Wang, Rui
• Format: Journal Article
• Language: English
• Published: 18-09-2023
• ISSN: 2633-5409; 2633-5409
• DOI: 10.1039/D3MA00269A

FeSe
2
nanorod@porous graphene films (FeSe
2
@PG) were prepared by simple vacuum filtration, annealing, and subsequent selenylation. These FeSe
2
nanorods were formed
via
confined oriented growth of FeSe
2
nanoparticles. The morphology of FeSe
2
@PG was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The interfacial interaction between FeSe
2
and graphene was investigated using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. When used as an anode in lithium-ion batteries, the FeSe
2
@PG electrode exhibited an initial reversible capacity of 858 mA h g
−1
, which was increased to 1053 mA h g
−1
after 50 cycles at 100 mA g
−1
. At high rates of 1, 2, 5, and 10 A g
−1
, the electrode maintained specific capacities of 483, 313, 265, and 178 mA h g
−1
, respectively, even after 1000 cycles. The excellent electrochemical performance of the FeSe
2
@PG electrode is attributed to the special structure of FeSe
2
@PG and the strong covalent bonds between graphene and FeSe
2
. Moreover, graphene can not only act as a substrate for the growth of FeSe
2
nanorods, but also improve the conductivity of FeSe
2
. Furthermore, the porous structure of graphene can reduce the diffusion path of lithium ions and improve the penetration of the electrolyte into the graphene layer. In addition, a new covalent bond of C–Se–Fe was formed between graphene and FeSe
2
, which was beneficial for maintaining its structural stability.