Patent ID: 8329328

Claim:
An electrical energy storage cell, comprising: a flat roll electrode that includes a strip of a positive electrode current collector foil having a cutaway portion and a positive electrode layer formed thereon, a strip of negative electrode current collector foil having a cutaway portion and a negative electrode layer formed thereon, and a strip of electrically insulated separator, wherein an inter-current-collector-foil electrolyte reservoir is provided between surfaces of the positive electrode current collector foil and the negative electrode current collector foil where the positive electrode layer and the negative electrode layer are not present, the strip of positive electrode current collector foil and the strip of negative electrode current collector foil being wound into a flat roll configuration with the strip of electrically insulated separator sandwiched therebetween; a sealed casing that hermetically seals the flat roll electrode having the inter-current-collector-foil electrolyte reservoir; and a positive terminal and a negative terminal each electrically insulated from the sealed casing, connected to the positive current collector foil and the negative current collector foil, respectively; wherein the positive current collector foil and the negative current collector foil oppositely extend away from the separator along a roll core axis, and each of the foils include edge portions having no positive layer or negative layer formed therewith; each of the negative current collector foil and the positive current collector foil is electrically coupled together in a lamination direction at the non-cutaway portions and each of the negative current collector foil and the positive current collector foil is electrically connected to the negative terminal and the positive terminal, respectively; and a pore diameter in the electrolyte reservoir is larger than that of the separator, at least either one of the negative current collector foil or the positive current collector foil is provided with through-holes.