Direct conversion of multilayer molybdenum trioxide to nanorods as multifunctional electrodes in lithium-ion batteries

• Published in: Nanoscale Vol. 6; no. 1; pp. 5484 - 549
• Main Authors: Ibrahem, Mohammed Aziz, Wu, Feng-Yu, Mengistie, Desalegn Alemu, Chang, Chia-Seng, Li, Lain-Jong, Chu, Chih Wei
• Format: Journal Article
• Language: English
• Published: England 21.05.2014
• Subjects: Charge; Electrodes; Insertion; Lithium-ion batteries; Molybdenum trioxide; Nanorods; Nanostructure; Reaction time; Specific surface
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c4nr00692e

In this study we prepared molybdenum trioxide (MoO 3 ) nanorods having average lengths of 0.5-1.5 μm and widths of approximately 100-200 nm through a one-step mechanical break-down process involving favorable fracturing along the crystal direction. We controlled the dimensions of the as-prepared nanorods by applying various imposing times (15-90 min). The nanorods prepared over a reaction time of 90 min were, on average, much shorter and narrower relative to those obtained over 30 min. Evaluations of lithium-ion storage properties revealed that the electrochemical performance of these nanorods was much better than that of bulk materials. As cathodes, the nanorods could deliver a high specific capacity (>315 mA h g −1 ) with losses of less than 2% in the first cycle at a rate of 30 mA g −1 ; as anodes, the specific capacity was 800 mA h g −1 at a rate of 50 mA g −1 . Relative to α-MoO 3 microparticles, these nanorods displayed significantly enhanced lithium-ion storage properties with higher reversible capacities and better rate performance, presumably because their much shorter diffusion lengths and higher specific surface areas allowed more-efficient insertion/deinsertion of lithium ions during the charge/discharge process. Accordingly, enhanced physical and/or chemical properties can be obtained through appropriate nanostructuring of materials. One-step direct conversion of bulk MoO 3 to nanorods displayed significantly enhanced lithium-ion storage properties with higher reversible capacities.