| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique for suppressing deformation of an electrode plate group. <P>SOLUTION: A lithium ion secondary battery 100 includes a positive electrode plate 5, a negative electrode plate 6, and a pair of separators 7. These are combined to form a wound electrode plate group 4. The electrode plate group 4 has a winding-starting part 41 and a power generation part 43. The winding-starting part 41 is formed by only the negative electrode plate 6, or only the negative electrode plate 6 and the separator 7. At the center of the electrode plate group 4, the number of windings of the winding-starting part 41 is one or more. The negative electrode plate 6 includes a preliminary part 6s forming the winding-starting part 41 and a main body part 6t forming the power generation part 43. Both the preliminary part 6s and the main body part 6t have a negative electrode active material layer 26 formed by a plurality of columnar bodies 11. <P>COPYRIGHT: (C)2013,JPO&INPIT |
