ELECTRODE MATERIAL FOR LITHIUM SECONDARY BATTERY, ELECTRODE STRUCTURE HAVING THE ELECTRODE MATERIAL, AND SECONDARY BATTERY HAVING THE ELECTRODE STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide an electrode material and an electrode for a lithium secondary battery exhibiting high lithium insertion/elimination efficiency.

SOLUTION: The electrode material for a lithium secondary battery comprises a particle 100 of an alloy containing silicon as a main component. The composition of the alloy is determined by a type of an element and an atomic ratio allowing component to completely melt together into a melted liquid state of the alloy. The alloy in a solid state comprises a phase selected from the group composed of a pure metal and a solid solution. The alloy particle 100 has a micro-structure in which microcrystalline or amorphous elements 102, 103 other than silicon are dispersed in microcrystalline silicon or amorphized silicon. A silicon content in the silicon alloy is not less than 50 wt.% and not more than 95 wt.%, and the silicon alloy is in the form of a fine particle. Further, the electrode material for a lithium secondary battery comprises silicon particles or silicon alloy particles wherein the silicon is doped with at least one element selected from a group composed of boron, aluminum, and gallium as a dopant in an atomic ratio of 10-8to 10-1.

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