Due to its low cost and high power density, the Zn/air energy system is considered to be a promising power energy source. Furthermore, Zn/air technology could be used as either an electrically or a mechanically rechargeable system. Electrical recharging is problematic, however, due to the formation of zinc dendrites. Similarly, hydrogen overpotential plays a major role. The present study attempts to reduce dendrite formation and raise hydrogen overpotential through the addition of cellulose and lead oxide, respectively. It is concluded that cellulose reduces dendrite formation to some extent. It also works well to raise the hydrogen overpotential even in the absence of lead oxide. (c) 2006 Elsevier B.V. All rights reserved.