Spinel lithium manganese oxide synthesized under a pressurized oxygen atmosphere

Abstract

Spinel lithium manganese oxide was synthesized via co-precipitation The prepared lithium manganese oxide powder was further heated at 700 degrees C for 15 h under pressurized (3 bar) oxygen atmosphere The resultant exhibited a highly crystalline cubic spinel phase with space group Fd3m as confirmed by X-ray diffraction The spinel compound exhibited a slightly smaller lattice constant than a conventional spinel compound even though the cationic ratio of Li/Mn is the same for both compounds Chemical titration of the Mn component showed that heat treatment under a 3 bar oxygen atmosphere resulted in slightly higher average Mn oxidation state indicating that the amount of Mn4(+) increased after the treatment The Li1 05Mn1 95O3 99 electrode exhibited improved cycling performance namely 96 3% of capacity retention during 100 cycles at elevated temperature (60 C) The details of the structure and electrochemistry of the electrode are discussed