Oxygen Nonstoichiometry in Li₂MnO₃: An Alternative Explanation for Its Anomalous Electrochemical Activity

Li 2 MnO 3 loses oxygen, reversibly, on heating above ∼600 °C. By 1100 °C, 1% of the oxygen has been lost, giving a stoichiometry of Li 2 MnO 2.97 . Depending on the synthesis conditions, materials with a range of oxygen contents may be produced. Associated with the variable oxygen content, partial reduction of Mn 4+ to Mn 3+ occurs, as demonstrated by a direct correlation between electrochemical capacity, when used as a cathode in a rechargeable Li test cell, and oxygen content.