| 摘要 |
<p>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 composite particles including tin (Sn) and cobalt (Co). The composite particles each have a structure in which the tin (Sn) is centered, and the cobalt (Co) is unevenly present, namely located on the external surface of the tin (Sn). The composite particles have an average particle diameter of 0.5-5.0μm. The composite particles include, as a constituent element, a third element consisting of any one of copper (Cu), silver (Ag), nickel (Ni) and lead (Pb). The atomic percentage of the third element is 1-40 atom% to the total quantity of the tin (Sn), the cobalt (Co) and the third element.</p> |
