Abstract: Some Todorokites containing Ca²⁺,Ba²⁺,Ni²⁺ were synthesized by having well defined crystals of nano phase W-MnO₂ reacted with various salts in which the positive ion radius or the electron structure was similar to the Mg ion. XRD patterns showed that their crystal structure were Todorokite but contained some unreacting W-MnO₂. The electrochemical behavior of those nano phase compounds were investigated by using cycling voltammetry and galvonostatic discharge tests in various electrolytes. The results indicated that the discharge capacities of Ca-T and Ba-T are far better than those of W-MnO₂.

Key words: doped Ca-Todorokite, doped Ba-Todorokite,doped Ni-Todorokite, constant current discharge, cycling voltammetry