KINETIC TRANSFORMATION OF SPINEL TYPE LiMn2O4 INTO TUNNEL TYPE MnO2
ABSTRACT: Lithiated phase
LiMn2O4 is a potential cathode material for high-energy batteries because it
can be used in conjunction with suitable carbon anode materials to produce
so-called lithium ion cells. The kinetic transformation of LiMn2O4 into
manganese dioxide (MnO2) in sulphuric acid has been studied. It is assumed that
the conversion of LiMn2O4 into R-MnO2 is a first order autocatalytic reaction.
The transformation actually proceeds through the spinel λ-MnO2 as an
intermediate species which is then converted into gamma phase of manganese
dioxide. In this reaction LiMn2O4 whose structure spinel type, which is packing
between tetrahedral coordination and octahedral coordination, is converted to
form octahedral tunnel structure of manganese dioxide, which is probably
regarded as a reconstructive octahedral-coordination transformation. Therefore,
it is a desire to investigate the transformation of manganese oxides in solid
state chemistry by analysing XRD powder patterns. Due to the reactions
involving solids, concentrations of reactant and product are approached with
the expression of peak areas.
Author: Daud K. Walanda
Journal Code: jpkimiagg070009
