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 nonaqueous couple. These techniques indicate three different stages of reduction by insertion of lithium ions into the lattice of the cathode. The initial stage of the reduction of the occurs within approximately the first 10% of discharge. It involves the insertion of lithium ions into the lattice of the forming . It is typical of a homogeneous reaction. The next step in the discharge involves a heterogeneous or two‐phase reaction. It is distinguished by the flat portion of the discharge curve . The final discharge regime is again a homogeneous reaction. This reaction involves insertion of lithium ions into the new structural form of and accounts for the final sloping section of the discharge curve.