An embodiment of the invention is a new method of making a polymer lithium ion battery with low cost, high efficiency and excellent quality. The new polymer lithium ion battery comprises four major components, each of which is a composite: an anode, a cathode, a polymer-gel-electrolyte-separator system and a soft packaging laminate. Adherent particles are introduced into the electrolyte and deposited on the surfaces of both separators and electrodes by Chemical Liquid Deposition (CLD) in-situ the battery cell during the battery assembly process. Those adherent particles not only serve as glue to strongly hold both the anode and cathode together with polyolefin separators, but also form a polymer-gelling electrolyte through the Polymer Gel Formation (PGF) process. The fabrication method creates a self-supporting and self-strengthening battery cell and allows a soft coffee bag laminate to be used as packing shell.