MANUFACTURE OF PASTE TYPE CADMIUM NEGATIVE ELECTRODE

摘要

PURPOSE:To improve negative electrode's capability of absorbing an oxygen gas and to prevent a charge-and-discharge characteristic from being deteriorated by dipping an electrode plate into a solution of metallic salt which keeps a potential higher in an alkaline solution than a metallic cadmium and has water-repellent fluorine resin powder suspended so that metal and fluorine resin powder are precipitated at the same time. CONSTITUTION:After a conductive core material is coated with paste of an active material, the core material is negatively electrolyzed in an alkaline solution to perform formation. A surface of the formation-finished electrode plate is coated with alkali- proof powder such as carbon powder, and this electrode plate is dipped into a solution of metallic salt which has a higher potential than metallic cadmium in an alkaline solution of nickel or the like and has fluorine resin powder of water-repellency such as PTFE suspended. A metallic layer is formed uniformly on the surface of the electrode plate, with the conductive powder as a core provided in advance on the surface of the electrode plate, by substitutional reaction performed between the metallic ions in the metallic salt and metallic cadmium produced by formation. The fluorine resin powder in the solution is precipitated at the same time so that a metallic matrix is made to grow also inside the electrode plate by the substitutional reaction.