| 摘要 |
PROBLEM TO BE SOLVED: To prevent a lithium ion from being trapped by a surplus negative electrode by a charging/discharging cycle to improve safety, by removing the electrode material in the innermost peripheral side surface portion of a positive electrode sheet, and in the outermost peripheral port portion of a negative electrode sheet. SOLUTION: Electrode material for a possitive electrode; obtained by kneading positive electrode active material containing a transition metallic compound, a binding agent, and conductive material; is coated on both surfaces of a sheet-like current collector except a side surface portion, and then is heat- treated to obtain a positive electrode sheet. Electrode material for a negative electrode; obtained by kneading negative electrode active material containing carbonaceous material, a binding agent, and conductive material; is coated on both surfaces of a sheet-like current collector except a side surface portion, to be heat-treated and pressed to obtain a negative electrode sheet. The positive and negative sheets are laminated via a separator, to be wound so that the positive and negative electrode sheets can be placed on the innermost and outermost peripheral sides respectively, to remove the electrode material from the innermost and outermost peripheral surface portions respectively. |
