Air-assisted electrochemical cell construction

Abstract

An electrochemical cell is disclosed including a cell housing, an ion-permeable, oxygen transmission restricting membrane that divides the interior of the cell housing into a first portion exposed to ambient air and a substantially air-tight second portion, an air electrode provided in contact with the membrane within the first portion of the cell housing interior that reoxidizes when exposed to ambient air, and a working cell provided in the substantially air-tight second portion of the cell housing interior. The working cell includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode is in contact with the membrane and is made of an electrochemically active material that is the same material that is used in the air electrode, such that the air electrode supplies ions to the positive electrode to thereby reoxidize the positive electrode as it discharges without exposing the negative electrode or the positive electrode of the working cell to oxygen from the surrounding air. Also disclosed is a spiral-wound electrode assembly that may be used with or apart from the above electrochemical cell. The spiral-wound electrode assembly includes wound strips of a positive electrode, a negative electrode, and a separator. The spiral-wound electrode assembly further includes a spacer for maintaining a space between the wound strips of negative and positive electrodes for collection and retention of reaction product produced during cell discharge. Preferably, the spacer is formed by alternatingly folded tabs provided along edges of one of the electrode strips.