화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.159, No.6, A904-A908, 2012
Thermal Lithiation of Manganese Dioxide: Effect of Low Lithium Concentration (x <= 0.3 in LixMnO2) on Structure and Electrochemical Performance
The effect of lithium concentration on LixMnO2 (x <= 0.3) materials prepared by co-precipitation/heating is investigated. Lithium concentration determines the phase formed, with three different phases identified in the concentration range. Low levels of lithiation (x = 0.08) leads to the formation of a gamma/beta type MnO2 material. As the lithium concentration is increased to x = 0.15, a lithiated gamma-MnO2 like phase is formed. Finally, at x = 0.28 tunnel structured monoclinic MnO2 is obtained. Increasing the concentration of lithium inhibits the formation of the undesired inactive Mn2O3 phase, which is formed upon heat-treatment of MnO2. At a 5 mA/g charge/discharge rate the monoclinic Li0.28MnO2 material gave the best performance, while at 30 mA/g the Li0.08MnO2 material proved superior. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.115206jes] All rights reserved.