Secondary Li cells. II. Characteristics of lithiated manganese oxides synthesized from LiNO3 and MnO2
Abstract The reaction between LiNO3 and MnO3 has been examined in details. It has been found that in selected experimental conditions the LiMnO phase thus formed is predominantly LixMnO2 (with x ∼0.2for a LiNO3: CMD ratio of 3: 7). Especially if CMD is pre-treated with HNO3, a material is obtained which, in button Li cells, delivers >; 0.15 Ah/g at 1 mA/cm2 for several cycles. The structure of this material is fairly resistant to lithiation and allows faster Li+ diffusion than pure MnO2. By impedance measurements, the evolution with cycle number of some cathode characteristics, such as DLi+, charge-transfer resistance and surface-layer resistance, have been followed. Preliminary tests have shown no capacity loss for a cycled cell during storage in the charged state.