Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqeuous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH OR DEVELOPMENT
This invention was made with government support under award number DE-AR0000062, awarded by Advanced Research Projects Agency--Energy (ARPA-E), U.S. Department of Energy. The government has certain rights in the invention.