Patent ID: 8263247

Claim:
An electrochemical cell comprising: an electrode comprising a current collector, and positive and negative active material layers disposed at both sides of the current collector and spaced apart from each other with a current collector extension part being located therebetween, wherein a polarity of the electrode is used as an opposite polarity in a neighboring cell; a hollow core; an electrolyte isolation barrier wall disposed at the current collector extension part of the electrode; a case accommodating an electrode assembly formed by winding at least one electrode including the electrode around the core; and an electrolyte injection port disposed in a side surface of the case and connected to an inside area of the core, wherein a plurality of first electrolyte injection holes are formed in the current collector extension part of the electrode at predetermined intervals, and one or more second electrolyte injection holes corresponding to the first electrolyte injection holes are formed in a sidewall of the core.