Oxidation State of Manganese in LiMn2O4 Powders and Its Effect on Electrochemical Properties
Lithium manganese oxide (LiMn2O4) powders for lithium ion batteries were synthesized from two separate raw material pairs, LiOH/MnO and LiOH/MnO2. The prepared powders and their electrochemical properties were investigated. Powders calcined at 780°C were composed of a single-phase spinel structure but those treated at 850°C showed a higher intensity ratio of I400 to I311, a slightly larger lattice parameter, and an increased discharge capacity by 10% under 3.0~4.3V voltage range. The XPS study on the oxidation states of manganese repealed that powders made from LiOH/MnO had less Mn3+ ion and gave better battery performances than those from LiOH/MnO2.
Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim
S. H. Kim et al., "Oxidation State of Manganese in LiMn2O4 Powders and Its Effect on Electrochemical Properties", Materials Science Forum, Vols. 534-536, pp. 1473-1476, 2007