IMPROVE- MENTS IN PRIMARY VOLTAIC BATTERIES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Peter Jensen at the Office of the
Commissioners of Patents on the 21st April 1883. Communicated to him
from abroad by Dr August Prinz, Wilhelm Wenzel and Josef Kahn all of
Vienna Austria
PETER JENSEN of 33, Chancery Lane, in the County of Middlesex "IMPROVE-
MENTS IN PRIMARY VOLTAIC BATTERIES." (A communication to me from abroad
by Dr August Prinz, Wilhelm Wenzel, and Josef Kahn, all of Vienna, Austria)
The object of this invention is to construct primary batteries in which a very
powerful-and constant current is produced in an economical manner.
I shall describe the invention as applied to a copper and zinc element whereby
diluted sulphuric acid is used as the conductor of the second order and where a
copper vitriol solution is used as a depolarizing fluid.
A piece of metallic zinc is covered with an envelope of parchment paper collodion
or other known membrane suitable for osmose this electrode is placed in an outer
bag made of like pervious material and containing diluted sulphuric acid. This
again is placed in a receptacle made of copper and perforated all round; this copper
vessel is coated inside and outside with membrane suitable for osmose and stands
in a container or vessel which is charged with saturated solution of copper vitriol to
which is also added free sulphuric acid. This copper vitriol solution must always
be kept saturated which is effected by placing therein pieces of copper vitriol.
When the two poles are connected the zinc will be attacked and oxydised by the
sulphuric acid through its coating membrane and will dialyse through the said
membrane into the pervious bag containing the sulphuric acid while only diluted
sulphuric acid comes to the zinc. Similarly the membranes with which the copper
is coated prevent metallic copper or hydrogen from being deposited thereon. The
pervious bag will consequently after some time contain a zinc vitriol solution, and
the copper reduced from the vitriol will consequently at once in its nascent state
again be transformed into sulphate of copper oxide, because the copper vitriol
solution contains free sulphuric acid as above stated. This continues, or in other
words, this element remains active until the concentration of the zinc vitriol
solution in the pervious bag has reached such a degree that it is indifferent to
the zinc.

page_text: Instead of zinc and copper, other metals or substances may be used which are
sufficiently far apart as regards electrical tension; thus, cadmium, nickel, iron,
manganese, zirconium, aluminium or magnesium may be used instead of zinc; and
silver, platinum, antimony or carbon may be used instead of copper.
The conductor of the first order (the exciting liquid used), will of course depend
upon the nature of the materials substituted for zinc, and similarly, the depolarizing
liquid used will depend upon the material used instead of the copper.
When the fluid in the pervious bag has become so saturated with metallic oxide
or metallic salt that it is indifferent to the zinc it has to be replenished with fresh
fluid, in the case here described diluted sulphuric acid.
The membrane material must of course be such as to withstand the acid employed
as long as possible.