title: Two-Dimensional SnO Anodes with a Tunable Number of Atomic Layers for Sodium Ion Batteries.
abstract: We have systematically changed the number of atomic layers stacked in 2D SnO nanosheet anodes and studied their sodium ion battery (SIB) performance. The results indicate that as the number of atomic SnO layers in a sheet decreases, both the capacity and cycling stability of the Na ion battery improve. The thinnest SnO nanosheet anodes (two to six SnO monolayers) exhibited the best performance. Specifically, an initial discharge and charge capacity of 1072 and 848 mAh g-1were observed, respectively, at 0.1 A g-1. In addition, an impressive reversible capacity of 665 mAh g-1after 100 cycles at 0.1 A g-1and 452 mAh g-1after 1000 cycles at a high current density of 1.0 A g-1was observed, with excellent rate performance. As the average number of atomic layers in the anode sheets increased, the battery performance degraded significantly. For example, for the anode sheets with 10-20 atomic layers, only a reversible capacity of 389 mAh g-1could be obtained after 100 cycles at 0.1 A g-1. Density functional theory calculations coupled with experimental results were used to elucidate the sodiation mechanism of the SnO nanosheets. This systematic study of monolayer-dependent physical and electrochemical properties of 2D anodes shows a promising pathway to engineering and mitigating volume changes in 2D anode materials for sodium ion batteries. It also demonstrates that ultrathin SnO nanosheets are promising SIB anode materials with high specific capacity, stable cyclability, and excellent rate performance.
authors.affiliation: Materials Science and Engineering, Physical Sciences and Engineering Division and ‡Imaging and Characterization Core Laboratories, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Materials Science and Engineering, Physical Sciences and Engineering Division and ‡Imaging and Characterization Core Laboratories, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
authors.forename: Jiajie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Materials Science and Engineering, Physical Sciences and Engineering Division and ‡Imaging and Characterization Core Laboratories, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
authors.forename: Daliang
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Materials Science and Engineering, Physical Sciences and Engineering Division and ‡Imaging and Characterization Core Laboratories, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
authors.forename: Udo
authors.identifier: 0000-0003-4179-7231
authors.initials: U
authors.lastname: Schwingenschlögl
authors.affiliation: Materials Science and Engineering, Physical Sciences and Engineering Division and ‡Imaging and Characterization Core Laboratories, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
authors.forename: Husam N
authors.identifier: 0000-0001-5029-2142
authors.initials: HN
authors.lastname: Alshareef
keywords: SnO nanosheets; Two-dimensional SnO; high-rate batteries; sodium ion battery