| abstract |
A secondary alkaline system, such as, for example, nickel-zinc, characterized by improved cycle life and superior volumetric energy density is provided in which the negative electrodes comprise a flat central portion with edges which have a greater amount of active material than does the central portion and positive electrodes having a flat central portion of substantially the same size as that of the negative electrode with edges having less active material than the central portion. In the preferred embodiment, the greater amount of active material at the edges is achieved in the negative electrodes by providing flared edges; and the lesser amount in the edges of the positive electrodes is obtained by forming the electrode with tapered edges. |