A dry cell of excellent performances, particularly in discharge characteristics, in which an ion-permeable barrier membrane is interposed between a cathode mixture and a negative electrode-consistuting zinc casing and more specifically between the cathode mixture and a paste layer, said membrane being of such a character that it blocks the transfer of water and a paste from the paste layer side to the cathode mixture side without being dissolvedduring storage and in the earlier stages of discharge of the cell, whereas it is dissolved to prevent a sharp increase of the zinc ion concentration in the vicinity of the paste layer in the latter stage of dscharge of the cell when the zinc ion concentration in the electrolyte is increased.
CROSS-REFERENCES TO RELATED APPLICATION
This application is a continuation-in-part of Ser. No. 843,598 filed on July 22, 1969 now U.S. Pat. No. 3,647,552.
Cathode-depolarizer mix cakes, bobbins or the like comprising manganese dioxide, conductive carbon, an aqueous solution of an ionic conductive material and a minor amount of a polyacrylamide binder for improving the strength and cohesiveness of the mix body.
A battery separator is provided that has 30-70% polyolefin synthetic pulp, 15-65% siliceous filler and 1-35% by weight of long fibers having lengths of between 1/4 and 1 inch. The long fibers may be polyester fibers or glass fibers or a mixture. Cellulose may be included in an amount up to about 10%. A process for forming the battery separator is also revealed using standard paper making equipment but employing ionic copolymers containing acrylamide in cationic and anionic combination to give good affinity of the siliceous material and polyolefin. Alum and other processing aids are also included as are other procedural steps such as pressing the web.
A battery separator is provided that has 30-70% polyolefin synthetic pulp, 15-65% siliceous filler and 1-35% by weight of long fibers having lengths of between 1/4 and 1 inch. The long fibers may be polyester fibers or glass fibers or a mixture. Cellulose may be included in an amount up to about 10%. A process for forming the battery separator is also revealed using standard paper making equipment but employing ionic copolymers containing acrylamide in cationic and anionic combination to give good affinity of the siliceous material and polyolefin. Alum and other processing aids are also included as are other procedural steps such as pressing the web.
