| 摘要 |
PROBLEM TO BE SOLVED: To produce a negative electrode active material with an inexpensive and commonly available material and a simple process and to improve energy density and cycle performance by using glass made by exchanging alkaline ions in oxide glass or sulfide glass for ions of an element constituting a compound along with lithium by an ion exchange method as the negative electrode active material. SOLUTION: Inexpensive alkaline aluminosilicate glass, alkaline silicate glass or alkaline aluminoborosilicate glass, and univalent cations of silver or thallium having high ion exchange speed are suitably used for oxide glass and element ions for exchanging, respectively. Since lithium is removed from and inserted into an amorphous glass matrix, volume variation in conjunction with it is absorbed so that the collapse of a crystalline structure never occurs. The process of the ion exchange method is simple and its condition control is not strict. The intensity difference between the peak values before and after the ion exchange of respective diffraction angles in an X-ray diffraction peak characteristic of the glass for the negative electrode is set to three times or less as much as the standard deviation of background intensity. |
