Hierarchical CuO hollow microspheres: Controlled synthesis for enhanced lithium storage performance

• Published in: Journal of alloys and compounds 2011-02, Vol.509 (7), p.3367-3374
• Main Authors: Guan, Xiangfeng, Li, Liping, Li, Guangshe, Fu, Zhengwei, Zheng, Jing, Yan, Tingjiang
• Format: Article
• Language: English
• Subjects: Alloys; ANODES; BATTERIES; Chemical synthesis; COPPER OXIDE; Cross-disciplinary physics: materials science; rheology; Electrochemical behavior; Exact sciences and technology; Lithium; Lithium batteries; Materials science; Methods of nanofabrication; Microspheres; Microstructure; Nanorods; Nanoscale materials and structures: fabrication and characterization; Ostwald ripening; Other topics in nanoscale materials and structures; Oxide materials; PARTICLES; Performance enhancement; Physics; Quantum wires; Self assembly; Transmission electron microscopy; VOIDS; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2010.12.067

Hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and these microspheres showed excellent cycle performance and enhanced lithium storage capacity. [Display omitted] ▶ Hierarchical CuO hollow microspheres were prepared by a hydrothermal method. ▶ The CuO hollow microspheres were assembled from radically oriented nanorods. ▶ The growth mechanism was proposed to proceed via self-assembly and Ostwald's ripening. ▶ The microspheres showed good cycle performance and enhanced lithium storage capacity. ▶ Hierarchical microstructures with hollow interiors promote electrochemical property. In this work, hierarchical CuO hollow microspheres were hydrothermally prepared without use of any surfactants or templates. By controlling the formation reaction conditions and monitoring the relevant reaction processes using time-dependent experiments, it is demonstrated that hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and that hierarchical spheres could be tuned to show different morphologies and microstructures. As a consequence, the formation mechanism was proposed to proceed via a combined process of self-assembly and Ostwald's ripening. Further, these hollow microspheres were initiated as the anode material in lithium ion batteries, which showed excellent cycle performance and enhanced lithium storage capacity, most likely because of the synergetic effect of small diffusion lengths in building blocks of nanorods and proper void space that buffers the volume expansion. The strategy reported in this work is reproducible, which may help to significantly improve the electrochemical performance of transition metal oxide-based anode materials via designing the hollow structures necessary for developing lithium ion batteries and the relevant technologies.