Cobalt, iron, and nickel can be doped into the layered alkali manganese dioxides, A(x)Mn(1-y)M(y)O(2) for A = K, Na, or Li and M = Co, Fe, or Ni, during the hydrothermal synthesis from the alkali permanganates. A single phase is obtained. The transition metal doping enhanced the electrochemical behavior in lithium cells. The manganese phases formed during cycling appear to depend on the rate of reaction; a spinel-like phase was formed at 1 mA/cm(2) whereas the layered phase is maintained at 0.1 mA/cm(2) independent of whether potassium or lithium ions reside between the MnO2 layers of the structure. Polarization is significantly less in the spinel-like regime.