| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery which is safe and has long lifetime. <P>SOLUTION: In the lithium ion secondary battery having an negative electrode in which negative electrode mixture layers containing an negative electrode active material are formed on both surfaces of an negative electrode collector made of aluminum or an aluminum alloy, a positive electrode in which a positive electrode mixture layer containing a positive electrode active material is formed on at least one surface of a positive electrode collector, a separator, and a nonaqueous electrolyte, the negative electrode contains lithium titanate as an negative electrode active material, and the positive electrode mixture layers of the positive electrode are respectively arranged on surfaces of the negative electrode via the separator. The mixture layers of the negative electrode and the positive electrode are formed so that: a capacity per unit area of the negative electrode mixture layer is larger than a capacity per unit area of the opposite positive electrode mixture layer on one surface of the negative electrode; and a capacity per unit area of the negative electrode mixture layer is smaller than a capacity per unit area of the opposite positive electrode mixture layer on the other surface of the negative electrode. <P>COPYRIGHT: (C)2011,JPO&INPIT |
