CHARACTERIZATION OF THE LI/MNO2 MULTISTEP DISCHARGE

The electrochemical discharge, differential capacity, open-circuit voltage-temperature dependence, and open-circuit relaxation techniques were combined to investigate the cathodic reduction mechanism of the Li/MnO//2 nonaqueous couple. These techniques indicate three different stages of MnO//2 reduction by insertion of lithium ions into the lattice of the cathode. The initial stage of the reduction of the MnO//2 occurs within approximately the first 10% of discharge. It involves the insertion of lithium ions into the lattice of the MnO//2 forming Li//xMnO//2 (0 less than equivalent to x less than equivalent to 0. 1). It is typical of a homogeneous reaction. The next step in the discharge involves a heterogeneous or two-phase reaction.