title: Bottom-up Approach Design, Band Structure, and Lithium Storage Properties of Atomically Thin γ-FeOOH Nanosheets.
abstract: As a novel class of soft matter, two-dimensional (2D) atomic nanosheet-like crystals have attracted much attention for energy storage devices due to the fact that nearly all of the atoms can be exposed to the electrolyte and involved in redox reactions. Herein, atomically thin γ-FeOOH nanosheets with a thickness of ∼1.5 nm are synthesized in a high yield, and the band and electronic structures of the γ-FeOOH nanosheet are revealed using density-functional theory calculations for the first time. The rationally designed γ-FeOOH@rGO composites with a heterostacking structure are used as an anode material for lithium-ion batteries (LIBs). A high reversible capacity over 850 mAh g(-1) after 100 cycles at 200 mA g(-1) is obtained with excellent rate capability. The remarkable performance is attributed to the ultrathin nature of γ-FeOOH nanosheets and 2D heterostacking structure, which provide the minimized Li(+) diffusion length and buffer zone for volume change. Further investigation on the Li storage electrochemical mechanism of γ-FeOOH@rGO indicates that the charge-discharge processes include both conversion reaction and capacitive behavior. This synergistic effect of conversion reaction and capacitive behavior originating from 2D heterostacking structure casts new light on the development of high-energy anode materials.
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Yong-Ning
authors.initials: YN
authors.lastname: Zhou
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Yuesheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Shang-Peng
authors.initials: SP
authors.lastname: Gao
authors.affiliation: Australia Synchrotron , 800 Blackburn Road, Clayton, 3168, Australia.
authors.forename: Qin-Fen
authors.initials: QF
authors.lastname: Gu
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Linfeng
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Materials Science, Fudan University , Shanghai 200433, P. R. China.
authors.forename: Dalin
authors.initials: D
authors.lastname: Sun
keywords: 2D heterostacking; band structure; electrochemical mechanism; lithium storage; unilamellar γ-FeOOH nanosheet