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Author Ragavendran, K. ♦ Sherwood, D. ♦ Vasudevan, D. ♦ Emmanuel, B.
Source CSIR-Central Electrochemical Research Institute
Content type Text
Publisher Elsevier
File Format PDF
Copyright Year ©2009
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword Electrodics and Electrocatalysis
Abstract Two batches of poly-crystalline lithium manganate were prepared by a fuel assisted solution combustion method. LiMn2O4(S) was prepared using starch as the fuel and LiMn2O4(P) was prepared using poly vinyl alcohol (PVA) as the fuel. XRD studies indicated a significant and consistent shift in the 2y values of all the hkl peaks to higher values in LiMn2O4(P) compared to LiMn2O4(S) indicating a lattice contraction in the former. TG DTA studies indicated a higher formation temperature (25 1C higher) for LiMn2O4(P). The higher formation temperature most likely promotes the oxidation of some Mn3+ to Mn4+ with a lower ionic radius causing a lattice contraction. This hypothesis is confirmed through XPS studies which indicated the presence of a higher fraction of Mn4+ in LiMn2O4(P) than that present in LiMn2O4(S). A crystal shape algorithm was used to generate the crystal habits of lithium manganate from their XRD data leading to an understanding on the exposed hkl planes in these materials. From the atomic arrangement on the exposed hkl planes it is predicted that LiMn2O4(P) would be less prone to manganese dissolution and hence would possess a higher cycle life when compared to LiMn2O4(S).
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2009-01-01
Journal PeerReviewed