Preparation of orthorhombic LiMnO2 material by quenching

Orthorhombic, LiMnO2 was synthesized using LiOH and gamma -MnOOH starting materials at 1000 degreesC in an argon atmosphere by quenching method. X-ray diffraction revealed that the LiMnO2 compound showed a well-defined orthorhombic phase of a space group with Pmnm. The lattice constants of the resulting compound were a = 2.806 Angstrom, b = 5.750 Angstrom, and c = 4.593 Angstrom, The LiMnO2 delivered 193 mAh/g in the first cycle and still delivered 183 mAh/g after 50 cycles at room temperature, We confirmed that the initial discharge capacity of LiMnO2 agreed well with its specific surface area and grinding treatment was effective in improving initial cycling performance. The well-defined orthorhombic LiMnO2 compound made by the quenching method exhibited an excellent cycle performance because it could maintain its original structure on cycling by suppressing transformation to the spinel structure. (C) 2001 The Electrochemical Society.