Structural Change of Li_<1-x>Ni_<0.5>Mn_<0.5>O_2 Cathode Materials for Lithium-ion Batteries by Synchrotron Radiation
Synchrotron X-ray diffraction and XAFS measurement have been employed to investigate structural change and the charging process of a layered LiNi<SUB>0.5</SUB>Mn<SUB>0.5</SUB>O<SUB>2</SUB> cathode material. The structure of charged Li<SUB>1−<I>x</I></SUB>Ni<SUB>0.5</SUB>Mn<SUB>0.5</SUB>O<SUB>2</SUB> (<I>x</I>=0.5), which corresponds to the composition for showing rechargeable capacity, was determined. The results showed that divalent nickel metal was oxidized to trivalent after charging, in association with the phase transition from hexagonal (<I>R</I>3-<I>m</I>) to monoclinic (<I>C</I>2/<I>m</I>) resulting from the ordering of cations in the layered structure.
- Chemistry letters
Chemistry letters 32(1), 60-61, 2003-01-05
The Chemical Society of Japan