Prismatic cell construction

An electrochemical cell comprising

• a sealed prismatic housing with two opposing broad sides having width and length and defining therebetween an internal cavity, the housing comprising
• a can defining a first of the broad sides of the housing, and
• a cover defining a second of the broad sides of the housing, one and the other of the first and second broad sides of the housing defining, respectively, concave and convex arcs each spanning substantially the length of the sides, the concave and convex arcs arranged in opposition such that the longitudinal centerline of the internal cavity defines a corresponding arc;
• the cell further comprising
• an electrode stack contained within the internal cavity of the housing, the electrode stack comprising positive and negative electrode sheets arranged in face-to-face relation and separated by a porous separator sheet, the electrode stack arranged between the broad sides of the housing such that the stack is deflected to follow the concave and convex arcs to maintain contact pressure between the positive and negative electrode sheets.

An electrochemical cell comprising a prismatic housing with two opposing, internal side surfaces defining therebetween an internal cavity having width and length,

• one of said side surfaces defining a convex arc,
• the other of said side surfaces having a center portion opposing the convex arc of the one side surface, and features extending toward the one side surface and straddling the convex arc;
• and
• an electrode stack contained within the internal cavity of the housing, the electrode stack comprising positive and negative electrode sheets arranged in face-to-face relation, the electrode stack arranged between said side surfaces of the housing such that the stack is retained between the one side surface and the extending features of the other side surface, and tensioned across the convex arc to maintain contact pressure between the positive and negative electrode sheets.

An electrochemical cell comprising

• a housing defining an internal cavity bounded on one
• side by a curved surface;
• and
• an electrode stack contained within the internal cavity of the housing, the electrode stack comprising positive and negative electrode sheets arranged in face-to-face relation, the electrode sheets arranged in tension substantially across the extent of the sheets and disposed to follow the curvature of said curved surface.

A method of constructing an electrochemical cell, the cell comprising

• a prismatic housing with two opposing broad sides having width and length and defining therebetween an internal cavity, the housing comprising
• a can defining a first of the broad sides of the housing, and
• a cover defining a second of the broad sides of the housing,
• one of the first and second broad sides of the housing defining a convex arc;
• and
• an electrode stack contained within the internal cavity of the housing, the electrode stack comprising positive and negative electrode sheets arranged in face-to-face relation and separated by a porous separator sheet;
• the method comprising the steps of
• arranging the electrode stack between the can and cover such that the electrode stack is disposed within the internal cavity of the housing with a face of the stack in contact with the convex arc;
• pressing the can and cover together, such that the electrode stack is deformed about the convex arc to produce contact pressure between the positive and negative electrode sheets;
• and
• attaching the can to the cover with the electrode stack in its deformed state.