TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: The polymer electrolyte is formed by dissolving a polymer (115) with a solvent that is capable of dissolving the polymer and then adding a solvent incapable of dissolving the polymer. The coating step is performed using a coating gun, coating roller, die, or screen-printing. It coats the polymer electrolyte on a single side or both sides of the positive electrode, negative electrode, and separator film. It results in a coverage ratio of 1-100%. The method includes enclosing the rechargeable polymer battery in a metal can or polymer aluminum foil.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The solvent incapable of dissolving the polymer is diethylene carbonate (DEC), dimethylene carbonate (DMC), and/or ethylene methylene carbonate (EMC). It includes first and second solvents. The first solvent is DEC, DMC, and/or EMC. The second solvent is propylene carbonate (PC), and/or ethylene carbonate (EC). The solvent capable of dissolving the polymer is PC and/or EC. The solvent capable of dissolving the polymer and the solvent incapable of dissolving the polymer are the electrolytic liquid of the battery. Preferred Concentration: The polymer electrolyte has a concentration of 0.1-15%.    TECHNOLOGY FOCUS - POLYMERS - Preferred Material: The polymer electrolyte is polyacrylonitrile or an acrylonitrile copolymer. EXAMPLE - A positive electrode, negative electrode, and polypropylene (PP) separator were coated with a polymer solution (1.2 g) and winded. The polymer solution was 3.75% polyacrylonitrile (PAN) dissolved in a mixed solvent of propylene carbonate and ethylene carbonate (1:1, w/w), and then a low boiling point lithium-containing solvent (2.4 g) was filled. The lithium-containing solvent was 2 M lithium phosphorus hexafluoride (LiPF6) dissolved in diethylene carbonate. The battery obtained had an electric capacity of 750 mAh. The battery was subjected to 50 cycles of charge/discharge and finally charged to saturation and then performed for the 12 V over-charge test. The charge current was set to 1 A. During the test, the voltage was measured between the positive and negative electrodes and the temperature was measured at three positions of the battery using three k-type thermocouples. As the time increased, the temperature and voltage also increased. At 55 minute, the voltage reached 12 V and temperature 95degreesC. After this time, the voltage stayed at 12 V and the temperature gradually decreased to room temperature. Result showed that the battery had passed the safety test, since it failed to explode or ignite before 12 V or experience dramatic temperature increase. After testing, the battery had no smoke or spark.