1839-1882. French engineer. In 1866 he
invented a primary electrical cell, the
Leclanche cell, which is still the basis of
most dry batteries. A Leclanche cell consists
of a carbon rod (the anode) inserted into a
mixture of powdered carbon and manganese
dioxide contained in a porous pot, which sits
in a glass jar containing an electrolyte
(conducting medium) of ammonium chloride
solution, into which a zinc cathode is
inserted. The cell produces a continuous
current, the carbon mixture acting as a
depolarizer; that is, it prevents hydrogen
bubbles from forming on the anode and
increasing resistance. In a dry battery, the
electrolyte is made in the form of a paste
with starch.