| 摘要 |
PROBLEM TO BE SOLVED: To provide a large lithium secondary battery having high safety by housing plural electrode groups, which are respectively formed of an elliptic spiral body of a layered structure of a sheet-like positive electrode, a sheet-like negative electrode and a separator, in a housing container, and connecting plural electrode groups to each other. SOLUTION: A lithium secondary battery is formed of a positive electrode and a negative electrode for flexibly storing lithium ion and a separator for partitioning the positive electrode and the negative electrode, and they are laminated in order of positive electrode, separator, negative electrode, separator so as to form a cylindrical spiral body, and thereafter it is pushed from both sides so as to form an elliptic spiral body of electrode group 10. Plural electrode groups 10 are used, and laminated (or arranged in parallel with each other) so as to obtain a desirable unit battery capacity. These electrode groups 10 are housed in a square battery can 14, and a positive electrode tab 15 and a negative electrode tab of each electrode group 10 are connected in parallel with each other, and they are respectively welded to a positive electrode terminal 17 and a negative electrode terminal 18 of a battery lid 16, and the battery lid 16 is fitted to the battery can 14. |
