Ketack Kim, Y. Cho, D. Kam
Aug 13, 2010
Citations
0
Influential Citations
24
Citations
Journal
Journal of Alloys and Compounds
Abstract
Abstract In this work, several organic acids are evaluated as reductants in the synthesis of LiFePO 4 , where FePO 4 is one of the starting materials. The investigated acids include formic, glycolic, oxalic, maleic, and malonic acids, which have minimal carbon content. Mono-carboxylic acids have favorable decomposition mechanisms as reductants compared to bi-carboxylic acids. On the other hand, bi-carboxylic acids follow a more complicated path to produce H 2 and H 2 O. Only one of the two carbonyl groups in bi-carboxylic acids is involved in producing CO, although there are slight variations among bi-carboxylic acids. When a reductant is not sufficiently strong to reduce all of the Fe(III)PO 4 , Fe 2 O 3 and Li 3 PO 4 are formed through ion exchange reactions between un-reacted Fe(III)PO 4 and LiOH. It is believed that the volatility of organic acids and the ion exchange reactivity of LiOH produce impurities. The replacement of organic acids and LiOH with less volatile mono-carboxylic acids and LiR (R = alkyl) may improve the purity of the LiFePO 4 obtained.