Bipolar lead-lead di:oxide electrode prodn. - by coating substrate foil in galvanic bath contg. carrier electrode(s) clamped between two metallic terminal electrodes

摘要

In the prodn. of bipolar lead/lead dioxide electrodes for galvanic primary elements, the substrate foil acting as the carrier electrode is coated on both sides simultaneously in a galvanic bath, in which are arranged one or more carrier electrodes, each clamped between two terminal electrodes made of lead and/or an acid-proof metallic conducting material. The electrodes to be galvanically coated are clamped in a frame comprising two parts made of electrically non-conducting and acid-proof material with the aid of a revolving O-ring. The frames are arranged plane-parallel to the two terminal electrodes in a bath container fitted with revolving slots on three sides. The bath container has a manifold for the electrolyte and two overflows between the slots. An electrolyte comprising 70-150 g/l of an aq. soln. of tetrafluoroboric acid and 150-800 g/l of tetrafluoroborate is used to deposit the metallic lead and Pb dioxide. USE/ADVANTAGE - No undesired galvanic deposition occurs. The electrolyte prevents the formation of dendrites of e.g., beta-Naphthol, urea and thiourea (claimed).