Abstract: A bipolar electrode element has an electrically conductive, chemically inert, generally flat wall having first and second opposing faces, each of the first and second faces having a plurality of spaced, parallel grooves therein with the spaced grooves in the first face being laterally staggered from the spaced grooves in the second face, first and second spaced and substantially parallel electrodes having first edges disposed within first and second respective grooves of said spaced parallel grooves in said first face and extending generally perpendicular from the plane of the inert wall; and a third electrode having a first edge disposed within a groove in said second face and extending generally perpendicular from the plane of the inert wall. A battery stack is obtained by positioning a plurality of the bipolar battery elements such that their electrodes are interdigitated.

Abstract: Particulate zinc oxide shaped of high surface area and improved crushing strength are prepared without extraneous binder by a process including forming normal surface area zinc oxide into shapes without binder, converting at least a portion of the zinc oxide to basic zinc carbonate by exposing the shapes in the presence of moisture, to a carbon dioxide-containing atmosphere and effecting substantially complete decomposition of the basic zinc carbonate. Conditions of bulk density, moisture content and temperature are controlled.