Synthesis of nanomaterials

• Main Author: Tay, Kai Yang.
• Other Authors: Srinivasan Madhavi
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Energy materials; DRNTU::Engineering::Materials::Nanostructured materials; DRNTU::Engineering::Materials::Material testing and characterization
• Online Access: http://hdl.handle.net/10356/44770
• Institution: Nanyang Technological University

LiMnPO4 is seen as a promising cathode material due to its high intercalation voltage of 4.1V and relatively high capacity of 170.9mA hg-1. Many synthesis methods have been employed to fabricate LiMnPO4. In this project, hydrothermal synthesis was used to fabricate LiMnPO4 powders. The amount of ascorbic and hydrazine reductants used during hydrothermal synthesis was explored. The morphology and purity obtained was characterized using SEM and XRD techniques. An increase in the amount of ascorbic acid reductants used will result in the formation of rod-like structures. However, the impurity phase also increases simultaneously. It was found that LiMnPO4 and ascorbic acid reductants with molar ratio of 26:1 can produce pristine and single phase LiMnPO4. Electrospinning is a novel method, which uses simple and straightforward techniques to fabricate LiMnPO4 nanofibers. The high aspect ratio obtained using such methods is hypothesized to have a better electrochemical performance. Two sets of electrospinning methods have been studied and established. It was found that the methods used for electrospinning LiFePO4 do not have the same ease of fabrication in the case of LiMnPO4. Another method, a modification of the hydrothermal LiMnPO4 synthesis method, has successfully produced nano-fibers with single phase.