| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery excelling in short circuit resistance while having a thin separator. <P>SOLUTION: The above problem is solved by this lithium ion secondary battery including: a positive electrode composed by forming a positive electrode mix layer containing an active material on one surface or each of both surfaces of a collector; a negative electrode composed by forming a negative electrode mix layer containing an active material on one surface or each of both surfaces of a collector; a separator; and a nonaqueous electrolyte; and characterized in that, in at least either of the positive electrode mix layer surface of the positive electrode and the negative electrode mix layer surface of the negative electrode, insulating particles having an allowable temperature limit above 150°C and an organic polymer resin binder are included, and a porous layer having surface roughness Ra below 1.0 μm is also included; and the thickness of the separator is not larger than 5% with respect to the total of the total thickness of the positive electrode and that of the negative electrode including the porous layer. <P>COPYRIGHT: (C)2009,JPO&INPIT |
