Patent ID: 8173289

Claim:
An electrical energy storage cell, comprising: a flat roll electrode that includes a strip of positive electrode having a positive current collector foil and a positive electrode layer formed thereon, a strip of negative electrode having an negative current collector foil and a negative electrode layer formed thereon, and a strip of electrically insulated separator, the strip of positive electrode and the strip of negative electrode 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 impregnated with an electrolyte; 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 edge portions is configured to include a cutaway portion where part of the edge portions is not existing so that the separator is exposed at the cutaway portion, and a non-cutaway portion constituting portions other than the cutaway portion; each of the positive current collector foil and the negative current collector foil is electrically coupled together in a lamination direction at the non-cutaway portions and electrically connected to the positive terminal and the negative terminal, respectively; and an electrolyte reservoir that makes a contact with the exposed separator is provided at each of the cutaway portions.