Abstract: A rechargeable battery having a zinc negative electrode, and a positive electrode preferably of nickel hydroxide, is provided with a novel dendrite barrier to prevent zinc spurs growing out of the zinc electrode during charge and shorting the battery. A novel separator pocket, which includes the barrier and is adapted to confine the zinc negative electrode against shape change, comprises an inner wrap of an absorbent film, an intermediate wrap of a microporous film, a next adjacent wrap of the flexible dendrite barrier, and an outer wrap pf a cellulosic film. This improved barrier is a porous, flexible sheet material comprising a substrate of a flexible, porous cloth woven from random fiber polypropylene in and through which is deposited a porous metal having a low hydrogen over-voltage to oxidize the zinc dendrites on contact in an alkaline electrolyte.