title: Self-assembled Co3O4hexagonal plates by solvent engineering and their dramatically enhanced electrochemical performance.
abstract: In this study, a facile two-phase solvothermal method was used to synthesize Co3O4nanocubes with high crystallinity and narrow size distribution (∼49 nm) for use in lithium-ion batteries. Here, oleylamine (OAm) was chosen as the solvent, surfactant, and reducing agent. After washing with the appropriate organic solvent, the Co3O4nanocubes self-assembled into hexagonal plates with a diameter and thickness of approximately 2.5 μm and 550 nm, respectively. Moreover, with the assistance of dipole-dipole and van der Waals interactions, the Co3O4nanocubes stacked along the [111] direction with their exposed facets attached, leading to their final exposed cross-sectional facet being (111). A possible assembling mechanism is proposed and explained in detail. Furthermore, the self-assembled (111) faceted Co3O4plates exhibited superior electrochemical capacity and stability to those original (001) faceted Co3O4nanocubes for Li+ion storage. Therefore, the solvent engineered self-assembly into secondary structures has proven to be a potential strategy for energy applications.
authors.affiliation: School of Materials Science and Engineering, Yeungnam University, Gyeongsan city, Gyeongbuk 712-749, Republic of Korea. sykim@yu.ac.kr.
authors.forename: W
authors.initials: W
authors.lastname: Zhao
authors.affiliation: School of Materials Science and Engineering, Yeungnam University, Gyeongsan city, Gyeongbuk 712-749, Republic of Korea. sykim@yu.ac.kr and Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Materials Science and Engineering, Hanseo University, Seosan, Chungnam 31962, Republic of Korea.
authors.forename: I Jin
authors.initials: IJ
authors.lastname: Kim
authors.affiliation: School of Materials Science and Engineering, Yeungnam University, Gyeongsan city, Gyeongbuk 712-749, Republic of Korea. sykim@yu.ac.kr.
authors.forename: S
authors.initials: S
authors.lastname: Kim