IMPROVE- MENTS IN GALVANIC BATTERIES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I GUSTAVUS BARON DE OVERBECK of 23 Ryder Street Saint James's in the.
County of Middlesex do hereby declare the nature of my invention for "IMPROVE-
MENTS IN GALVANIC BATTERIES a communication to me from abroad by
Dr Ferdinand Hornung of Berlin to be as follows:-
נו
The effectiveness of my battery depends on the great readiness with which
certain compounds of oxygen with chlorine part with their oxygen to oxidisable
substances.
Such compounds of chlorine are employed throughout in order to remove from
the element the hydrogen generated which would otherwise produce polarisation'
(so called) whereby as is well known a rapid diminution of the initial strength of
the current is brought about.
The soluble electrode in all the galvanic combinations hereinafter contained is
zinc which may be amalgamated or not. The opposite electrode may consist of
carbon, platinum, or platinized carbon. It is desirable to increase the surface of:
carbon by surrounding the solid carbon with fragments of the same material
especially if a current of great density be required but it is not absolutely
necessary.
As exciting fluid for the zinc I employ an aqueous solution of common salt
(sodium chloride) or potassium chloride or else soda or potash lye.
As exciting fluid for the carbon (depolarising liquid) I employ an aqueous solution
of a hypochlorite (salt of hypochlorous acid) or free chloric acid or free perchloric
acid.
It is not at all necessary to procure the above mentioned chemicals in an
absolutely pure state as the ordinary rough products answer perfectly well.
As the bypochlorite solution a solution of hypochlorite of lime (chloride of lime)
may be used but it is desirable in order to increase the electrical conductivity to
add so much sodium chloride (common salt) or potassium chloride as will make the
specific gravity of the fluid from 1-130 to 1-140. The solution of common salt at
the zinc pole should have the same degree of concentration in order to prevent'
endosmosis

page_text: There is of course nothing to forbid the employment of other degrees of
concentration but it should be borne in mind that weak solutions are not good
conductors while on the other hand strong solutions in open vessels may produce
efflorescence. The very easily soluble salt, potassium-chloride, however admits of
the employment of any desired degree of concentration without any disadvantage.
Instead of a solution of hypochlorite of lime a solution of hypochlorite of soda
or potash may be used. The product known in commerce and the arts as Eau de
Javelle for example is such a solution. It is desirable in this case also to add a
little sodium chloride or potassium chloride if the specific gravity of the preparation
as obtained be less than 1.130.
It is advantageous to maintain the above solutions in a somewhat alkaline
condition.
Instead of the solution of the hypochlorites I employ aqueous solutions of free
chloric acid or free perchloric acid. These acid solutions may be readily obtained
by decomposing their salts with dilute sulphuric acid. An excess of sulphuric
acid is here quite harmless but serves on the contrary to raise the conductivity of
the solution. The same may be said of the acid alkaline sulphate also existing in
the solution, if the corresponding alkaline salt has been decomposed.
Elements charged with the above described fluids are distinguished by their
great constancy and strength of current; the chemicals employed are neither
themselves poisonous nor do they give rise to any poisonous or noxious gases or
vapours; nor does any consumption either of the electrodes or the fluids go on
when the element is not in use from which it results, that the expense of generating
the unit of current strength is the smallest possible.
Among many points the element can be relied on as being wholly without smell;
in such cases free chlorine (of course in aqueous solution) or a solution of hypo-
chlorous acid may be used. In the same way the zinc may be placed in dilute
sulphuric acid or hydrochloric acid or sulphate of zinc.
My galvanic elements and batteries may be arranged as follows:
-

page_text: sea- or table-salt or the so called "Abraumsalz" either singly or mixed with one
another.
8. The use of sea water for the production of the solutions mentioned in clauses 1
to 6 inclusive for the purposes therein specified.
II. ELEMENTS WITH A SINGLE FLUID.
9. Zinc, either alone or amalgamated, and carbon or platinum or platinized
carbon, both immersed in a mixed solution of caustic potash and hypochlorites
with or without the addition of chlorates or sulphates of the alkalies or both of
those bodies.
10. Zinc, either alone or amalgamated, and carbon, or platinum or platinized
carbon, both in a solution of chlorine hypochlorous acid, chloric acid or perchloric
acid, either singly or mixed with one another, or mixed with salts of the alkalies or
stronger mineral acids (sulphuric, nitric and hydrochloric acid).
11. The same for 9 and 10 as in clauses 7 and 8.
12. The employment or addition of calcium chloride or magnesium chloride or
both of those bodies for the production or improvement of the fluids used in the
combinations mentioned in clauses 1. 2. 3. 4. 5, 9 and 10 as well those for the zinc
as those for the carbon and those for both electrodes.

page_text: COMPLETE SPECIFICATION.
"
I, GUSTAVUS BARON DE OVERBECK of 23 Ryder Street Saint James's in the
County of Middlesex do hereby declare the nature of my invention for "IMPROVE-
MENTS IN GALVANIC BATTERIES (a communication to me from abroad by
Dr Ferdinand Hornung of Berlin) and in what manner the same is to bé
performed to be particularly described and ascertained in and by the following
statement:-
The effectiveness of my battery depends on the great readiness with which
certain compounds of oxygen with chlorine part with their oxygen to oxidisable
substances.
Such compounds of chlorine are employed throughout in order to remove from
the element the hydrogen generated which would otherwise produce polarization
(so called) whereby as is well known a rapid diminution of the initial strength of
the current is brought about.
The soluble electrode in the galvanic combinations hereinafter contained is zinc
which may be amalgamated or not, or iron or other electro positive metal may be
employed. The negative electrode may consist of carbon platinum or platinized
carbon. It is desirable to increase the surface of carbon by surrounding the solid
carbon with fragments of the same material especially if a current of great density
be required, but it is not absolutely necessary.
As exciting fluid for the electro-positive metal I employ an aqueous solution of
common salt (sodium chloride) or potassium chloride or soda or potash lye or else
dilute acid.
As exciting fluid for the carbon (depolarizing liquid) I employ an aqueous solution
of a hypochlorite (salt of hypochlorous acid) or free chloric acid or free perchloric
acid.
It is not at all necessary to procure the above mentioned chemicals in an
absolutely pure state as the ordinary rough products answer perfectly well.
As the hypochlorite solution, a solution of hypochlorite of lime (chloride of
lime) may be used but it is desirable to add sodium chloride or potassium
chloride.
Instead of a solution of bypochlorite of lime, a solution of hypochlorite of soda
or potash may be used. The product known in commerce and the arts as Eau de
Javelle for example is such a solution. It is desirable in this case also to add a
little sodium chloride or potassium chloride if the specific gravity of the preparation
as obtained be less than 1.130.
It is advantageous to maintain the above solutions in a somewhat alkaline
condition.
Instead of the solution of the hypochlorites I employ aqueous solutions of free
chloric acid or free perchloric acid. These acid solutions may be readily obtained
by decomposing their salts with dilute sulphuric acid. An excess of sulphuric acid

page_text: is here quite harmless, but serves on the other hand to raise the conductivity of the
fluid. The same may be said of the acid alkaline sulphate also existing in the
solution, if the corresponding alkaline salt has been decomposed.
Elements charged with the above described fluids are distinguished by their
great constancy and strength of current the chemicals employed are neither them-
selves poisonous nor do they give rise to any poisonous or noxious gases or
vapours, nor does any consumption either of the electrodes or the fluids go on
when the element is not in use, from which it results that the expense of generating
the unit of current strength is the smallest possible.
My galvanic elements and batteries may be arranged as follows :—
I. ELEMENTS WITH TWO FLUIDS.
1. Zinc either alone or amalgamated or other electro positive metal in an aqueous
solution of an alkaline chlorate-carbon or platinum or platinized carbon in a mixed
solution of chloride of lime (hypochlorite of lime) with sodium chloride (common
salt) or potassium chloride or both of those bodies.
2. The same as in 1, but the carbon in a solution of the hypochlorite of an alkali
or in a solution of a mixture of the hypochlorite of an alkali with the sulphate or
chlorate of an alkali or both of those bodies.
3. The same as in 2, but the zinc or other electropositive metal in a solution of
the sulphate of an alkali or in a solution of the mixture of the sulphate and
chlorate of an alkali.
4. The same as in 1 and 2 but the zinc either alone or amalgamated in a solution
of caustic soda or caustic potash or both of those bodies or in a solution of a
mixture of caustic alkalies or sulphates of alkalies or of both caustic alkalies and
alkaline sulphates.
5. The same as in 1, 3 and 4, but the carbon (or platinum or platinized carbon)
in a solution of chlorine, hypochlorous acid, chloric acid or perchloric acid either
singly or mixed with one another or mixed with the salts of the alkalies or the
stronger mineral acids (sulphuric, nitric, or hydrochloric acids) or mixed with both
alkaline salts and mineral acids.
6. The same as in 1, 2 and 5 but the zinc &c in dilute sulphuric or hydrochloric
acid or a solution of zinc sulphate or zinc chloride or a mixture of those bodies.
7. As a special form of the chlorates and sulphates of the alkalies mentioned in
clauses 1 to 5 concentrated sea-water or the soluble residue of the preparation of
sea or table salt either singly or mixed with one another.
8. The same as mentioned in clauses 1 to 6 inclusive but with sea water used for

page_text: Having now particularly described and ascertained the nature of my sala
invention and in what manner the same is to be performed I declare that what
I claim is
The use of a hypochlorite (salt of hypochlorous acid) or free chloric acid or free
perchloric acid to remove the element hydrogen from the carbon or other insoluble
electrode.
I also claim the several combinations of battery electrodes and fluids herein set
forth.