Deconvolution of the electrolytic manganese dioxide (EMD) discharge curve has indicated the presence of a number of energetically different reduction processes. This has been used to determine the contribution of each reduction process to the total discharge. Using step potential electrochemical spectroscopy ( SPECS), the i-t data were modelled as the sum of the discharge of the individual reduction processes. From this, A root D for each reduction process as a function of degree of discharge was determined. The maximum A root D values for each process ranged from 2.3 x 10(-2) to 4.0 x 10(-4) cm(3) s(-1/2) g(-1) values are consistent with previously reported values for A root D, although in this case we have determined values for the entire compositional range.