NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, AND LITHIUM ION SECONDARY BATTERY ARRANGED BY USE THEREOF

摘要

PROBLEM TO BE SOLVED: To manufacture a lithium ion secondary battery having a high capacity, superior cycle and output characteristics and a long life.SOLUTION: A negative electrode active material for lithium ion secondary batteries comprises: metal nanoparticles including tin (Sn) and a second element. The second element is one kind of cobalt (Co), copper (Cu), silver (Ag), nickel (Ni), or lead (Pb). The metal nanoparticles have an average particle diameter of 5-150 nm. The atomic percentage of the second element is 1-45 atom% to the total quantity of the tin (Sn) and the second element.