酸素雰囲気下におけるLiNiO_2のペチーニ法合成メカニズム

概要

論文の詳細を見る
Pechini process was known as an excellent method for the synthesis of LiNiO_2 powder. Compared with the result of solid state reaction using NiO and Li_2CO_3 as reactants, Ni_2O_3 was the new compound found in Pechini-processed powder. In the present work, the role of Ni_2O_3 and the reaction mechanism for the synthesis of Pechini-processed LiNiO_2 were studied. XRD and DTA/TG analysis were used to investigate the phases present and the thermal reaction in the Pechini process studied. It was found that Ni_2O_3 was obtained from nickel citrate and nickel acetate which released a large amount of heat during calcination. Based on the thermodynamic calculation, Ni_2O_3 is not a stable compound in the oxidizing environment. As a result, Ni_2O_3 decomposes into NiO, and the decomposed NiO reacts with Li_2CO_3 and forms LiNiO_2 at 700℃. An isothermal kinetics study was performed on the mixture of NiO, Ni_2O_3 and Li_2CO_3 at 700℃. The result indicates that the decomposition of Ni_2O_3 into NiO takes place at the beginning hour of the isothermal reaction. Consequently, NiO and Li_2CO_3 are consumed due to the formation of LiNiO_2. Based on the results obtained, the reactions for Pechini-processed LiNiO_2 may be described by the following reactions: Citrate complex → Li_2CO_3 + NiO + Ni_2O_3 Ni_2O_3 → 2NiO + 1/2O_2 x/2Li_2CO_3 + (2-x)NiO + x/4O_2 → Li_xNi_2-xO_2 + x/2CO_2 (0<x≦1) This reaction is rationalized on the basis of the instability of Ni_2O_3 and the structural similarity between NiO and LiNiO_2.
社団法人日本セラミックス協会の論文
2002-12-01

酸素雰囲気下におけるLiNiO_2のペチーニ法合成メカニズム

スポンサーリンク

概要

著者

関連論文

スポンサーリンク