Electroactive material for secondary batteries and methods of preparation

An electroactive composite material, comprising:

• a first electroactive material, said electroactive material comprising MeI capable of alloying with a species selected from the group consisting of alkali metals and hydrogen;
• and
• a second material having the first active material intimately mixed therein, said second material comprising MecIIXd, where 0.5<c/d<3 and X is one of oxygen, boron, carbon, nitrogen, phosphorus, fluorine, chlorine, bromine, or iodine,
• wherein the first material is in a state of tensile stress or the composite has void space in its interior.

An electrode for a lithium battery, comprising:

• a first electroactive material comprising a phase enriched in a metal or metal alloy, MeI, capable of alloying with lithium;
• and
• a second material having the first electroactive material intimately mixed therein, said second material comprising a metal oxide, MeyIIOz, where 0.5<y/z<3,
• wherein MeI has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise MeIIO.

A lithium battery, comprising;

• a cathode;
• an anode comprised of a first electroactive material comprising a phase enriched in a metal or metal alloy, MeI, capable of alloying with a species selected from the group consisting of alkali metals and hydrogen;
• and a second material having the first electroactive material intimately mixed therein, said second material comprising a metal oxide, MeyIIOz, where 0.5<y/z<3, wherein MeI has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise MeIIO;
• and
• an electrolyte in ionic and electrical contact with the anode and cathode.