| 摘要 |
PROBLEM TO BE SOLVED: To improve the cyclic characteristics of discharging/charging of a battery by covering at least one side surface of plane part of a planar winding core by means of a resin-made thin film, in a thin battery. SOLUTION: In a process of composing an oval spiral polar plate group, a positive electrode 3, a negative electrode 4 and two sheets of separator 5 are set in a predetermined position and these 4 sheets are pinched by means of two rollers. A heater is placed in pushing contact with 2 sheets of separator 5 from above them so as to place a planar winding core and two sheets of separator 5 in thermal deposition via a resin having thermal deposition property. By turning a planar winding core so as to wind the separator 5 around it, and also the positive electrode 3 and the negative electrode 4 are wound around it. In the planar winding core, at least on one side surface of a flat plate, a resin-made sheet in polyolefin system, etc., having thermal deposition property is formed by lamination. There is no need to make spot welding the negative electrode 4 on the planar winding core, thus causing neither undesirable possibility to damage any electrode nor internal short-circuit owing to welding spatter. |
