NEGATIVE-ELECTRODE MATERIAL AND LITHIUM SECONDARY BATTERY USING SAME

摘要

The present invention aims at providing a material which repeatedly undergoes a conversion reaction and an alloying reaction to have an improved coulombic efficiency in a first cycle of the repeating, and thereby allowing the material to serve as a high-electrical capacity negative electrode of a lithium secondary battery. In order to attain the object, a negative-electrode material is made by mixed dispersion of (i) nanoparticles of an electrical conducting material having electronic conduction and (ii) nanoparticles of an electrode active material which is reducible to a simple substance which undergoes an alloying reaction with lithium. The electrical conducting material is a sulfide having electronic conduction, and the electrode active material is a sulfide of an element which undergoes the alloying reaction with lithium. Further, the element which undergoes the alloying reaction with lithium is silicon.