Patent ID: 8382861

Claim:
A method of preparing a gel polymer Li-ion battery, characterized in that the Li-ion battery comprises a single Li-ion battery cell or a plurality of vertically-laminated Li-ion battery cells, and that said method includes the following steps: a) coating a surface of a polyester film with a polyurethane adhesive, roller- or flat-pressing a metal foil and the pre-coated polyester film, thereby obtaining a polyester composite film covered with the metal foil on the surface; b) coating the polyester composite film covered with the metal foil with two kinds of slurries of a positive electrode active material and a gel polymer electrolyte by using a two-layer one-step coating process, thereby obtaining a three-layer structural composite layer of the polyester/metal foil composite film, the positive electrode active material and the gel polymer electrolyte; c) coating a polyester composite film covered with a metal foil with a Li battery negative electrode material slurry, thereby obtaining a two-layer structural composite layer of the polyester/metal foil composite film and the negative electrode material; d) laminating, and flat- or roller-pressing the composite layers obtained in steps b) and c), heating and curing, thereby obtaining a gel polymer Li-ion battery cell; e) welding the metal foils of positive electrode and negative electrode with metal lugs; and f) vacuum-packing the battery cells, thereby obtaining the gel polymer Li-ion battery.