Electrochemical cell having wound electrode structures

DETAILED DESCRIPTION As an aspect of the invention, an electrical cell which has two electrode structures wound into a coil.
The electrode structures are separated by a multiplicity of porous insulating sheets.
One of the electrode structures has a metal substrate with bare borders and a bare end, free of electrode material.
The bare borders of the substrate and porous insulating sheets extended beyond the other electrode structure of the coil, and the bare end of the substrate is arranged on the outside of the coil.
The coil is fitted into a cylindrical metal case with a metal cover in contact with the case.
The substrate and porous insulating sheet are in contact with the metal case and the metal cover.
The substrate is also in contact with the cylindrical wall of the case.
The aforecited copending application divulges an electrochemical cell wherein the cathode current collector electrode has a metal substrate carrying a plurality of holes.
The metal substrate supports layers of an electrode material such as porous carbon.
Both edges and one end of the substrate is kept free of the material.
The bare end of the substrate is on the outside of the coil.
The substrate is wider than other elements of the coil, so that when the coil is inserted in the can, the substrate makes contact with all the internal surfaces of the can.
The coil is substantially immersed in an electrolytic solution.
The foregoing arrangement is a significant advance over the prior art as it provides for uniform heat sinking along the entire length of each cathode electrode structure by virtue of the fact that edges of the substrate bear against the case bottom and cover and that a winding of the substrate presses against the cylindrical wall of the case.
This is believed to reduce the possibility of internal hot spots.
This arrangement also provides short, uniform conductive paths for current flow, and thus losses due to internal resistance are the same throughout the battery stack.
The distance from the cathode current collector to the active anode material is the same throughout the battery stack