Year: 1897

page_text: We, ALEXIS WERNER and PAUL DE KILDUCHEVSKY, of 49, Bernard Street, W.C.,
in the County of London, Enginers, this adress is applicable to both applicants,
do hereby declare the nature of this invention to be as follows:-
All systems of electric accumulators now in use are based on the electrolysis of
water. On the products resulting from the decomposition of water, the oxygen
only enters into chemical combination whereas the other product hydrogen develops
into gas; the negative plate of the accumulator is intended to fix the latter by
purely mechanical means.
This hydrogen merely accumulates between the pores of the negative matter,
which consequently should present a large surface, and as lead or salts of lead are
used for this purpose considerable weight is entailed.
In consequence of the occlusion of bydrogen gas in the negative plate during
charge and discharge variations of volume are produced which eventually disintegrate
completely the negative matter in forming short circuits.
Besides this the recombination of hydrogen and oxygen which is the source of
energy in the accumulator, only produces electro-motive force of 2 volts.
The object of the present invention is to provide a new system of accumulator
which has the following advantages:
:-
1. To substitute extremely light and negative plates for the usual heavy ones.
2. To completely avoid the disintegration of negative matter.
3. To increase the electro-motive force from 20 to 40 % (or on an average about
25%).
The positive electrodes of our accumulator are the same as those in ordinary use;
for instance, grids of lead or an antimonious lead filled with oxyde of lead.
Our negative electrodes are formed out of thin galvanised sheet of copper zinc or
any metal, covered by an alloy formed by zinc and magnesium, or by cadmium or
magnesium. This alloy is deposited during the charging of the accumulator,
and is redissolved during the discharge. It is clear that the proportions of
the materials forming this alloy must depend on the electrolyte and on the
intensity of the current.
The electrolyte is formed by a solution of the following bodies.
Sulphate of zinc or cadmium.
Sulphate of magnesia.
Sulphate of soda or of potash or of ammonia.
The proportions of the bodies used for forming the electrolyte vary according to
the electro-motive force desired.
For an electro-motive force of 2.3 volts to 2.4 volts, we use the following
proportions :-

page_text: For all electro-MTOTO
Sulphate of zinc
Sulphate of magnesia
Alkaline sulphate
from 70 to 60 %
25 30 %
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5 10 %
The before-mentioned alloy zinc magnesium or cadmium-magnesium is very
hard and attacked by acids with great difficulty and very hardly by diluted sulphuric
acid. The hydrogen formed in a slight quantity during charging is confined
between the molecules of the very hard matter and well combined chemically with
the metals of the alloy so as to constitute one of its integral constituents. When
using little sulphate of magnesia the electro-motive force is about 2.4. By
increasing the proportion of sulphate of magnesia and the intensity of the
current 2.5 and 2.6 and even 3 volts are obtainable but the alloys formed become
more corrodible by the acids and it becomes necessary to solidify the bath and
render it gelatinous by the means well-known. When using the cadmium bath we
prefer a combination of sulphate of cadmium sulphate of zinc and sulphate of
magnesium; with this combination the deposit obtained is extremely hard and the
electro-motive force is about 2 volts: when used in open circuit there is hardly any
waste.
Improvements in Electric Accumulators.
We, ALEXIS WERNER and PAUL DE KILDUCHEVSKY, both formerly of 49, Bernard
Street, London, and now of 44, Queen's Road, Peckham, London, S.E., do hereby 2
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:—
Electrical accumlators or secondary batteries are based on the electrolysis of
water, the oxygen resulting from the decomposition of the water alone entering into a
chemical combination, the function of the negative plate of the accumulator being to
fix by purely mechanical means the hydrogen evolved in the gaseous state. This
hydrogen merely accumulates in the pores of the negative material which must
therefore present a very large surface and as it is of lead or salts of lead it follows
that its weight is very considerable.
3
In consequence of the occlusion of hydrogen gas in the negative plate there is
produced during the charge and discharge, variations of volume which ultimately
have for effect to cause the complete disaggregation of the negative material and
short circuiting. Moreover the re-combination of the hydrogen with the oxygen,
which is the source of energy of the accumulator, will produce an electrical energy 4
of but two volts.

page_text: The positive electrodes of the accumulator are the same as usual, for instance
grids of lead or antimony-lead filled with lead oxide.
The negative electrodes are formed of thin sheets of galvanized iron, of copper,
zinc, or any other metal covered with an alloy formed of zinc, magnesium, and
cadmium, this alloy being deposited thereon during the charging of the accumulator
and becoming redissolved during the discharge. The proportions of the constituent
elements of the alloy will obviously depend on the electrolyte and the intensity of
the current. We may also employ very thin grids of antimony-lead or other
metal unattackable by sulphuric acid, filled with a paste formed of lead, zinc, and
cadmium in the spongy metallic form, these grids having the advantage of
permitting the use of solutions of less density and having consequently less electrical
resistance.
In the pores of this pasty mass the alloy above specified and hydrogen are
deposited from the electrolyte.
The electrolyte is formed of a solution of the following salts :—
Instead however of using sulphate of zinc the sulphate of any metal of the iron
group may be used, viz. :-iron, chromium, nickel, and cobalt, in which case the
corresponding metal will take the place of zinc in the alloy deposited on the
negative plates.
The hydrogen formed in small quantity during the charging is imprisoned
between the molecules of the very hard alloy and in all probability it combines
chemically with the metals of the alloy in order to constitute one of its integral
parts.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what we
claim is:-
:-
1. In an electric accumulator the employment as an electrolyte of a solution
containing the combination of cadmium and magnesium sulphates with another
sulphate as specified.
2. In an electric accumulator the employment as negative electrodes in
combination with the electrolyte above specified, of thin plates covered with an alloy
of cadmium, magnesium and zinc or other metal specified, which is deposited
thereon in charging as specified.
3. In an electric accumulator the employment as negative electrodes in
combination with the said electrolyte, of grids of antimony-lead (or other metal

page_text: unattacked by sulphuric acid) pasted with a compound of spongy metallic lead,
zinc, and cadmium, in the pores of which the alloy above specified and hydrogen
are deposited from the electrolyte.