Nonaqueous electrolyte secondary cell and method of producing the same

The present invention provides a nonaqueous electrolyte secondary cell having a construction wherein a flat spiral-shaped electrode assembly, in which positive and negative electrodes capable of intercalating and deintercalating lithium ions are wound with a separator disposed therebetween, is enclosed in a casing which changes shape with a slight increase in the internal pressure of the cell, a gel polymer containing a nonaqueous liquid electrolyte exists between the positive electrode and the separator, bonding the positive electrode and the separator, and the adhesive strength between the separator and the positive electrode is 0.02 N/10 mm or higher. In the above construction of a nonaqueous electrolyte secondary cell, even when the cell is overcharged and gas is generated in the cell, explosion caused by detachment of the bonded portion of the positive electrode and the separator is prevented.