The aim of the present paper was to study the influence of foam type as well as nickel and cobalt additives on cell performance and cycle life of cylindrical nickel-zinc cells. Experiments have shown that discharge capacity depends on the foam type of nickel electrodes and is significantly improved by using thicker foam substrates (2.2 mm). AA-size nickel-zinc cells constructed of two thinner nickel electrode layers (1.6 mm) displayed stronger decline in capacity during cycle life due to a very low zinc/nickel hydroxide ratio (1.1-1.2). The addition of nickel and cobalt powder was investigated by means of resistivity measurements of PVA-bonded nickel hydroxide films. This study elucidated that small amounts of cobalt (2-8 wt.%) caused an extreme decline in resistivity. Admixture of nickel also lowered resistivity but not as great as cobalt. The cell performance turned out to be contrary to resistivity measurements; nickel-zinc cells prepared with a less conductive slurry delivered higher capacities. However, discharge capacity decreased rapidly after prolonged cell cycling, as the zinc/nickel hydroxide ratio of these cells was also considerably reduced. (C) 2004 Elsevier B.V. All rights reserved.