| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a means that prevents the occurrence of various problems caused by expansion and contraction of an active material during discharge and charge when a silicon material is used as a negative electrode active material in a lithium ion secondary battery. <P>SOLUTION: The lithium ion secondary battery includes a battery element having at least one unit cell layer including: a positive electrode having a positive electrode active material layer containing a positive electrode active material and formed on the surface of a collector; an electrolyte layer containing an electrolyte; and a negative electrode having a negative electrode active material layer containing a negative electrode active material and formed on the surface of the collector, wherein both electrodes are layered in this order so that the positive electrode active material layer and the negative electrode active material layer face each other. In addition, the electrolyte includes a liquid electrolyte in which cations of a metallic element that is alloyed with lithium are dissolved in an organic solvent. Further, the negative electrode active material contains silicon doped with at least one kind of doping element selected from the group consisting of the elements in group XIII or group XV. <P>COPYRIGHT: (C)2010,JPO&INPIT |
