鋰錳氧及鎳鐵氧超微粉體之製備

• Main Author: 何欣戎
• Other Authors: 陳東煌
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/22764116774524760274

碩士 === 國立成功大學 === 化學工程學系 === 88 === Ultrafine particles have great potential applications in the development of various materials. LiMn2O4 and NiFe2O4 can be used as the cathodic materials of lithium-ion secondary batteries and the magnetic materials, respectively. The reduction in their particle sizes is an important tendency. In this thesis, the ultrafine LiMn2O4 and NiFe2O4 powders are prepared and the effects of preparation conditions on particle sizes are investigated. For the preparation and characterization of ultrafine LiMn2O4 powders, the powders have been prepared by Pechini process, citrate gel method, and PAA sol-gel method. The results indicated that, for three processes for the production of ultrafine powders, the particle size increased and the specific surface area decreased as the calcination temperature was raised. For the preparation of LiMn2O4 powders by the Pechini process, the powders obtained at a calcination temperature of 600℃ had a diameter ranging from 50 to 100 nm and a specific surface area of 28.5 m2/g. For the preparation of LiMn2O4 powders by the citrate gel method, the powders obtained at a calcination temperature of 600℃ had a average diameter of 50 nm and a specific surface area of 15.4 m2/g. For the preparation of LiMn2O4 powders by the PAA sol-gel method, the powders obtained at a calcination temperature of 500℃ had a diameter ranging from 50 to 100 nm and a specific surface area of 12.3~37.9 m2/g. The increase in the PAA content was helpful for the dispersion of powders and led to the production of the powders with smaller size and larger specific surface area. For the preparation and characterization of NiFe2O4 ultrafine powders, the powders have been prepared by sol-gel method. The powders obtained at a calcination temperature of 300℃ had a diameter ranging from 5 to 30 nm, a specific surface area of 30~55 m2/g, the saturation magnetization of 44.2~52.3 emu/g, and coercivity of 31.7~102.4 Oe. The increase in the PAA content was helpful for the dispersion of powders and led to the production of the powders with smaller size and larger specific surface area.