Dry Cell

 

In 1888 the first 'dry' cells were developed by Carl Gassner.
These are where an outer zinc can serves both as container and as the negative electrode. The positive electrode, a carbon rod, is immersed in a manganese dioxide/carbon black mixture. This is separated from the zinc container by a folded paper sack, soaked in a solution of ammonium chloride which acts as the electrolyte. During use the zinc casing of the battery is gradually consumed by the chemical reaction. A bitumen seal prevents evaporation of water from the electrolyte and the ingression of oxygen.
This development of the Leclanché cell still is the basis of the common zinc/carbon battery and its higher powered brother the zinc chloride battery, which remain the largest selling battery type world wide.