Bulk Synthesis of Crystalline and Crystalline Core/Amorphous Shell Silicon Nanowires and Their Application for Energy Storage

• Published in: ACS nano Vol. 5; no. 10; pp. 8383 - 8390
• Main Authors: Chen, Haitian, Xu, Jing, Chen, Po-chiang, Fang, Xin, Qiu, Jing, Fu, Yue, Zhou, Chongwu
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.10.2011
• Subjects: Chemical vapor deposition; Crystal structure; Maximum power; Nanostructure; Nanowires; Silicon; Silicon substrates; Synthesis; Three dimensional; spheres; bulk synthesis; three-dimensional synthesis; silicon nanowires; Li-ion battery; crystalline core/amorphous shell
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/nn203166w

Silicon nanowires (NWs) have stimulated significant interest and found numerous applications; however, many applications will require a bulk quantity of nanowires to be synthesized in a reliable way. In this paper, we report the bulk synthesis of silicon nanowires on millimeter scale Al2O3 spheres with a thermal chemical vapor deposition system (CVD) via the vapor–liquid–solid (VLS) growth mechanism. The spherical substrates enable the realization of Si nanowire synthesis on three-dimensional surfaces in comparison with the synthesis on a planar, two-dimensional wafer substrate. By modifying temperature in the recipe of synthesis, both single-crystalline and crystalline core/amorphous shell Si nanowires were obtained with this nanowire-on-spherical-support method. Conspicuous distinction in crystallinity of the nanowires was revealed by transmission electron microscopy characterization. The crystalline core/amorphous shell Si nanowires were utilized to form the anode of Li-ion battery half-cells with the traditional slurry method. Galvanostatic measurement demonstrated that the maximum power capacity achievable by the electrodes was 3500 mAh/g and capacity sustained at 1100 mAh/g after 60 cycles of charging and discharging.