NOVELTY - A pregel composition with a moisture content of 1,000 ppm or less as determined by Karl Fischer titration. The pregel composition when added to an organic electrolyte solution of an electrolyte salt in a non-aqueous solvent, causes the solution to gel and form a polymer gel electrolyte.    USE - For forming a polymer gel electrolyte used in secondary cells and electrical double-layer capacitors (all claimed). The secondary cell,e.g. lithium secondary cells and lithium ion secondary cells, are used in the main power supplies and in the memory back-up power supplies for portable electronic equipment such as camcorders, notebook computers, mobile telephones, personal handy phone systems, uninterruptible power supplies for personal computers, in transport devices such as electric cars and hybrid cars, and together with solar cells as energy storage systems for solar power generation. The electrical double layer capacitor is used in memory backup power supplies for electronic equipment such as personal computers and wireless terminals, uninterruptible power supplies for personal computers, in transport devices such as electric cars and hybrid cars, together with solar cells as energy storage systems for solar power generation, and in combination with batteries as load-leveling power supplies.    ADVANTAGE - The pregel composition has a low moisture content and can be prepared in less time and at lower temperatures than the with conventional method. The polymer compound in the composition has high adhesive properties and increases the physical strength of polymer gel electrolytes. The polymer compound in combination with a reactive double bond containing organic compound forms an interpenetrating network or semi-interpenetrating network structure, thus providing a high affinity between electrolyte solvent molecules and ionic molecules. The compound also allows for high ion mobility, dissolve the electrolyte salt to high concentration and has high ionic conductivity. Polymer gel electrolytes prepared with pregel composition have good electrochemical stability. The secondary batteries and electrical double layer capacitors can be operated at high capacity and high current, have high output voltage, large output current and a broad service temperature range without compromising their outstanding characteristics such as excellent charge/discharge efficiency, high energy density, high output density and long life.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of dehydrating a pregel composition comprising azeotropic distillation of a pregel composition in the presence of an entrainer which is the non-aqueous solvent in the organic electrolyte solution, for lowering the moisture content of the composition to 1000 ppm or less as determined by Karl Fischer titration;    (2) a polymer gel electrolyte formed using the pregel composition;    (3) a secondary cell comprising a positive electrode, negative electrode and an electrolyte comprising the polymer gel electrolyte prepared by adding the pregel composition to an organic electrolyte solution of an electrolyte salt in a non-aqueous solvent, this induces gelation; and    (4) an electrical double layer capacitor comprising a polymer gel electrolyte between a pair of polarizable electrodes.