Year: 1899

page_text: Date of Application, 15th Dec., 1899
6353
I, CARL LUCKOw, Junior, of Palmstrasse 36, Cologne, in the Empire of Germany,
Electro-Chemist, do hereby declare the nature of this invention to be as follows:
My purpose is, in the most simple manner and with slight expenditure of power
to loosen the surfaces of suitable metal bodies, by the single and direct action of
electrolysis, thus rendering them suitable for the storage of electricity, in such
a manner that these bodies, used as electrodes in accumulators, will combine
with great durability a capacity of easily storing and discharging electricity
hitherto unattained for practical purposes.
By the electrolysis of the electrolyte hereinafter described, the metal bodies,
placed as electrodes in specially constructed suitable vessels, are covered to the
desired even thickness, primarily at the expense of the smooth substance repre-
senting the positive pole and of the solvent of the electrolyte, with adhering
layers of encrustations of great density, but with extremely fine pores, consisting
of their own oxydes and of finely distributed or spongey metal.
This part of the process therefore, is a so called Planté formation.
necessary conditions are as follows:-
The
As material for the electrodes I use such metals as are suitable, in the first line,
of course, most of the heavy metals, namely those whose specific weight is above 5,
preferably in the form of sheets or similar bodies. With due consideration for the
thickness of solid metal absolutely necessary to give the desired durability or
lasting capacity, it should as a rule be sought to obtain as great an extent as
possible of suitable surface to be covered by the electrolytic deposit. Conse-
quently the 'active' surface will as a rule not be even, but covered with holes,
grooves, and hollows of various shapes, but not great extent, which also serve to hold
thick active layers. Weak or thin plates are therefore subjected to treatment
either with a sand blast, using coarse, sharp-edged sand, or with stiff metal-
brushes, or steel-combs, or toothed rollers, or with acids and caustic agents, while
stronger or thicker plates it is best to manufacture in the shapes which have
proved themselves suitable for the storage of electricity, such as ribbed plates,
wire netting and such like.
•
The electrolytes used are the hydroxyle (OH) combinations of alkaline metals
and alkaline earth metals, also called alkaline hydroxydes and alkaline earth
hydroxydes, or caustic alkalis and alkaline earths, in largely diluted aqueous solu-
tions. The desired results however, are only obtained, and therein lies the principle
of the invention, if in the mixture of the electrolyte substance and the solvent
(water, H₂O) the latter is added in such preponderating quantities that the electro-
lytic dissociation of the dissolved particles reaches a very high degree, that is,
when the coefficient of dissociation, representing the proportion of the number of
decomposed molecules to the whole, approaches 1 very closely. The molecules of
the bases mentioned, all of them electrically neutral when whole, have, by the
overwhelming dissociating force of the water, almost all been split into their

page_text: - ions, the metal ions (cathions), charged with positive electricity (+) and the
hydroxyle ions (anions), charged with negative electricity (-), for instance,
hydroxyde of sodium, NaOH into positive Na + negative Oli, calcium hydroxyde,
Ca (OH) into positive Ca + negative OH + OH and so forth, there remain
therefore in the solution only few un-decomposed neutral (normal) molecules,
without independent power of motion. The molecules of the substances dissolved
exist therefore in a condition of extreme decomposition. The behaviour of a
substance under such conditions is characterized by uniformity and comparable to
that of gas. The ideal electrolyte is thus almost attained.
1000 parts by weight of the solution therefore do not generally contain more
than 1 part by weight of the hydroxydes mentioned, in no case more than 3 parts
by weight. The reaction of the solutions is alkaline. As is well-known they
have the characteristic of gradually absorbing from the atmosphere carbonic acid
gas, CO, for instance a solution of NaOH in H₂O-the so-called soda lye
contains after a time the easily soluble carbonate of soda Na,CO, when exposed to
the air, while a solution of Ca(OH), in H2O--the so-called lime-water-becomes
cloudy through the carbonate of calcium, CaCo₂, being eliminated in consequence
of its total or partial lack of solubility.
The electrolytes, should therefore be kept from contact with CO₂ as much as
possible, which is easily accomplished in practice, for instance, by neutralizing the
acidity of the air in the chamber in which the process is carried on by means
of lime-white or lime-paste,—that is, solutions of Ca (OH)2 in lime-water. How-
ever, this acidifying of the caustic lye, and formation of alkaline carbonates may
be left to take its course as long as it does not effect the action by increased
consumption of power and slower formation of electrode surface.
The tension of the current varies on the average between 2 and 3 volts.
The capacity of the current is generally, in round figures, from 10 to 20 amperes
to the square metre of active positive surface; I ani however, at liberty to use
currents of considerably greater capacity.
It is best to keep the temperature moderate.
A simple example of the process for small requirements is given below.
Fig. 1 represents a vertical front section; Fig. 2 a vertical side section of the
vessel containing the electrolyte, while Fig. 3 gives a plan view of the vessel, the
lines X-X and Y-Y indicating the respective positions of the above-mentioned
sections.
The material chosen for the electrodes is lead Pb. The five electrodes a b c d
and e, are cut out of rolled lead, and as shown in the drawing vertical grooves
have been made in them with a strong steel-comb. They are suspended in the
glass-vessel f. The two copper wires 9 connect on the one hand a c and e, on the
other band d, with the respective poles. f is filled with the electrolite, consisting
of strongly diluted aqueous alkaline lye, made by adding to every 5 litres of
distilled water H₂O only 20 cubic cmtrs. of aqueous alkaline lye, of the specific
gravity of 1,130 and containing therefore nearly 15 per cent. of hydroxyde of
pottassium, KOH.
a canle are then connected with the positive, 6 and d with the negative pole
and the electrolyte subjected to the electrolytic action of a current of 1.5 amperes
capacity in the course of which the E.M.F. of current will reach an average of
about 3 volts. As soon as.free electricity begins to accumulate on the electrodes,
the ions in the solution move towards the submerged surfaces of the electrodes
charged with the opposite kind of electricity to themselves, thus setting up the
electrolytic or galvanic current. In consequence of the electrical power now in
operation the ionazation of the metal representing the positive pole now begins
to take place, the active submerged surfaces of a cand e beginning to dissolve into
positive ions, which however, discharge their electricity on the surface of the
metal itself or at least in more or less close proximity to it, and combine with
the OH ions thereabouts into neutral molecules of hydroxyd of lead Pb(OH),
which are insoluble, or rather, not easily soluble in electrolytes.

page_text: During the first few moments of the electrolysing process, however, the
Pb(OH), molecules do not adhere to the surfaces of the metal on which they form,
but in consequence of their greater specific weight slide in the form of powder or
flakes down the metal surface to the bottom of the bath, where the precipitate
gradually accumulates. In the further process of the electrolysis, however, the
Pb (OH), adheres more to the metal surfaces, so that in a short time the submerged
surfaces of solid metal are closely covered with strongly adhering, highly porous
and soft layers of Pb(OH), causing a considerable increase in bulk, while the solid
metal core gradually dissolves away. Gradually on the oxygen 0 becoming
nascent and on the formation of H₂O in the more advanced degrees of the oxydation
of Pb, the Pb(OH), becomes converted into the oxyd of lead, PbO, and peroxide of
lead, PbO, and intermediate stages so that in the end there is upon the active
surface of the metal a layer of PbO, more or less infected by most of the other
oxydes of lead, which latter, but especially Pb(OH), form the binding material.
As the oxydization progresses, of course the at first soft and delicate particles
forming the layer gradually form a crust of increasing firmness and density.
Upon the submerged surfaces of the negative plates 6 and d the same current
produces a quantity of ions of pottassium K, equivalent to that of OH ions. As,
however, the former immediately react vigorously upon the solution they do not
adhere to the metal, so that the solution of KOH in the negative zone is constantly
restored and in consequence hydrogen becomes nascent on the negative surfaces,
from whence it escapes in the form of little bubbles.
Generally speaking, therefore, two processes take place on the positive surfaces
during the electrolysis.
Primarily the ionazation of the anode metal and,
Secondarily, the reformation of the ions in the form of insoluble, or not easily
soluble oxydes upon the surface of the metal.
On the negative surfaces also two processes take place.
Primarily, the separation of alkalis and earth alkalis on the surfaces of the
metal, and
Secondarily, the decomposition of H₂O and reformation of the caustic lyes, H
becoming nascent.
After about 8 days the poles are interchanged that is to say the current is
reversed, so that a c and e then represent the negative and 6 and d the positive
pole. The latter then, of course, go through the corresponding part of the
process described above, while on the negative surfaces the H which becomes
nascent reduces before escaping the layers of oxyde to freely divided Pb.
After further 6 days the electrolysis is discontinued, so that then b and d on the
one hand are encrusted in layers of oxyde and a cand e on the other with layers
of divided lead.
Within the period of formation of about 8 6 days described I am at liberty
to interchange the poles 3 times instead of once, and thus divide the period of
formation into 4 + 3 and 4 + 3 days. Doing so results in considerable
economy of force, but also in greatly reducing the quantity of PbO, in the layers
of oxyde, and thereby correspondingly increasing that of Pb(OH)2.
The period of formation can be shortened at will, for instance to 4 + 3 days,
as in electrodes with specially large surfaces the formation is generally not 80
deep. It is also always possible to somewhat decrease and even increase the
intensity of the process, by using in the mixture of the electrolyte instead of
the 20 cbc. cmtrs., mentioned, 25 cbc. cmtrs. or only 15 cbc. cmtrs. respectively.
The loosening of the leaden plates for the purpose of storing current has thus
been accomplished; they are, therefore taken from the bath and prepared for use
as electrodes in an accumulator-cell containing for instance, as electrolyte, diluted
aqueous sulphuric acid H₂SO, of the best possible conducting capacity.
The spongy lead plates a cand e are immediately lixiviated in water, after which
it is best to press them between india-rubber rollers to remove superfluous water,
and then they are placed as negative pole-plates in the accumulator-cell.

page_text: The oxyde-plates b and d however, it is advisable to subject as positive pole-
plates at least 24 or 48 hours, to electrolysis in diluted aqueous solution of car-
bonate of pottassium, K,CO,, of best possible conducting capacity with a current
of 3 amperes. In order to convert the lower stages of oxidation especially Pb(OH),,
more thoroughly into PbO. The peroxide plates are then also lixiviated in water,
and introduced into the accumulator cell, after the superfluous water has run off,
as positive pole plates.
If desired the accumulator-cell can be completely fitted with spongy lead plates.
For this purpose the spongy lead plates a c and e are replaced, after the formation
process has been completed by fresh, polished electrodes of the same material. The
latter are then subjected to electrolysis, whereby at the same time the oxyde
layers on b and d are reduced. After the process of converting into spongy lead,
band d are treated in the same manner as a cand e and then used as positive
pole-plates in the accumulator-cell. The first time the latter is charged the spongy
lead of 6 and d is converted into PbO₂.
Dated this 15th day of December 1899
HERBERT HADDAN & Co.,
Agents to Applicant.
A Method of Producing Electrodes for Electrical Accumulators.
I, CARL LUCKOW, Junior, of Palmstrasse 36, Cologne, in the Empire of Germany,
Electro-Chemist, do hereby 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:-
My purpose is, in the most simple manner and with slight expenditure of power
to loosen the surfaces of suitable metal bodies, by the single and direct action of
electrolysis, thus rendering them suitable for the storage of electricity, in such
a manner that these bodies, used as electrodes in accumulators, will combine
with great durability a capacity of easily storing and discharging electricity
hitherto unattained for practical purposes.
By the electrolysis of the electrolyte hereinafter described, the metal bodies,
placed as electrodes in specially constructed suitable vessels, are covered to the
desired even thickness, primarily at the expense of the smooth substance repre-
senting the positive pole and of the solvent of the electrolyte, with adhering
layers of incrustations of great density, but with extremely fine pores, consisting
of their own oxides and of finely distributed or spongey metal.
This part of the process therefore, is a so called " Plante" formation.
necessary conditions are as follows:-
The
As material for the electrodes I use such metals as are suitable, in the first line,
of course, most of the heavy metals, namely those whose specific weight is above 5,
preferably in the form of sheets or similar bodies. With due consideration for the
thickness of solid metal absolutely necessary to give the desired durability or
lasting capacity, it should as a rule be sought to obtain as great an extent as
possible of suitable surface to be covered by the electrolytic deposit. Conse-
quently the 'active' surface will, as a rule not be even, but covered with holes,
grooves, and hollows of various shapes, but not great extent, which also serve to hold
thick 'active' layers. Weak or thin plates are therefore subjected to treatment
either with a sand blast, using coarse, sharp-edged sand, or with stiff-metal-
brushes, or steel-combs, or toothed rollers, or with acids and caustic agents, while
stronger or thicker plates it is best to manufacture in the shapes which have

page_text: proved themselves suitable for the storage of electricity, such as ribbed plates,
wire netting and such like.
The electrolytes used are the hydroxyle (OH) combinations of alkaline metals"
and alkaline earth metals, also called alkaline hydroxydes and alkaline earth
hydroxydes, or caustic alkalis and alkaline earths, in largely diluted aqueous solu-
tions. The desired results however, are only obtained, and therein lies the principle
of the invention, if in the mixture of the electrolyte substance and the solvent
(water, H₂O) the latter is added in such preponderating quantities that the electro-
lytic dissociation of the dissolved particles reaches a very high degree, that is,
when the coefficient of dissociation, representing the proportion of the number of
decomposed molecules to the whole approaches 1 very closely. The molecules of
the bases mentioned, all of them electrically neutral when whole, have, by the
overwhelming dissociating force of the water, almost all been split into their
- ions, the metal ions (cathions), charged with positive electricity (+) and the
hydroxyle ions (anions), charged with negative electricity (-), for instance,
hydroxyde of sodium, NaOH into positive Na + negative OH, calcium hydroxyde.
Ca (OH) into positive Ca + negative OH + Oй and so forth, there remain
therefore in the solution only few un-decomposed neutral (normal) molecules,
without independent power of motion. The molecules of the substances dissolved
exist therefore in a condition of extreme decomposition. The behaviour of a
substance under such conditions is characterized by uniformity and comparable to
that of gas. The ideal electrolyte is thus almost attained.
1000 parts by weight of the solution therefore do not generally contain more
than 1 part by weight of the hydroxydes mentioned, in no case more than 3 parts
by weight. The reaction of the solutions is alkaline. As is well-known they
have the characteristic of gradually absorbing from the atmosphere carbonic acid
gas, CO, for instance a solution of NaOH in H2O-the so-called 'soda-lye'-
contains after a time the easily soluble carbonate of soda Na,CO, when exposed to
the air, while a solution of Ca(OH), in H₂O-the so called lime-water-becomes
cloudy through the carbonate of calcium, CaCo, being eliminated in consequence
of its total or partial lack of solubility.
The electrolytes should therefore be kept from contact with CO, as much as
possible, which is easily accomplished in practice, for instance, by neutralizing the
acidity of the air in the chamber in which the process is carried on by means
of lime white or lime-paste,—that is, solutions of Ca (OH), in water.
How-
ever, this acidifying of the caustic lye, and formation of alkaline carbonates may
be left to take its course as long as it does not effect the action by increased
consumption of power and slower formation of electrode surface.
The tension of the current varies on the average between 2 and 3 volts.
The capacity of the current is generally, in round figures, from 10 to 20 amperes
to the square metre of active positive surface; I am however at liberty to use
currents of considerably greater capacity.
It is best to keep the temperature moderate.
A simple example of the process for small requirements is given below.
Referring to the drawings filed with my Provisional Application :-
Fig. 1 represents a vertical front section."
Fig. 2 a vertical side section of the vessel containing the electrolyte, while
Fig. 3 gives a plan view of the vessel, the lines X-X and Y-Y indicating the
respective positions of the above-mentioned sections.
The material chosen for the electrodes is lead Pb. The five electrodes a b c d
and e, are cut out of rolled lead, and as shown in the drawing vertical grooves
have been made in them with a strong steel-comb. They are suspended in the
glass-vessel f. The two copper wires 9 connect on the one hand a c and e, on the
other b and d, with the respective poles. f is filled with the electrolyte consisting
of strongly diluted aqueous alkaline lye, made by adding to every 5 litres of
distilled water H₂O only 20 cubic centrs. of aqueous alkaline lye, of the specific

page_text: gravity of 1.130 and containing therefore nearly 15 per cent. of hydroxyde of
potassium KOH.
a cand e are then connected with the positive b and d with the negative pole
and the electrolyte subjected to the electrolytic action of a current of 1.5 amperes
capacity in the course of which the E.M.F. of current will reach an average of
about 3 volts. As soon as free electricity begins to accumulate on the electrodes,
the ions in the solution move towards the submerged surfaces of the electrodes
charged with the opposite kind of electricity to themselves, thus setting up the
electrolytic or galvanic current. In consequence of the electrical power now in
operation the ionazation of the metal representing the positive pole now begins
to take place, the active submerged surfaces of a c and e beginning to dissolve into
positive ions, which however, discharge their electricity on the surface of the
metal itself or at least in more or less close proximity to it, and combine with
the OH ions thereabouts into neutral molecules of hydroxyd of lead Pb(OH)₂,
which are insoluble, or rather, not easily soluble in electrolytes.
During the first few moments of the electrolysing process, however, the
Pb(OH), molecules do not adhere to the surfaces of the metal on which they form,
but in consequence of their greater specific weight slide in the form of powder or
flakes down the metal surface to the bottom of the bath, where the precipitate
gradually accumulates. In the further process of the electrolysis, however, the
Pb(OH), adheres more to the metal surfaces, so that in a short time the submerged
surfaces of solid metal are closely covered with strongly adhering, highly porous
and soft layers of Pb(OH), causing a considerable increase in bulk, while the solid
metal core gradually dissolves away, gradually on the oxygen becoming
nascent and on the formation of H₂O in the more advanced degrees of the oxydation
of Pb, the Pb(OH), becomes converted into the oxyd of lead, Pb0, and peroxide of
lead, PbO, and intermediate stages so that in the end there is upon the active
surface of the metal a layer of PbO, more or less infected by most of the other
oxydes of lead, which latter, but especially Pb(OH), form the binding material.
As the oxydization progresses, of course the at first soft and delicate particles
forming the layer gradually form a crust of increasing firmness and density.
Upon the submerged surfaces of the negative plates b and d the same current
produces a quantity of ions of potassium K, equivalent to that of OH ions. As,
however, the former immediately react vigorously upon the solution they do not
adhere to the metal, so that the solution of KOH in the negative zone is constantly
restored and in consequence hydrogen becomes nascent on the negative surfaces,
from whence it escapes in the form of little bubbles.
Generally speaking, therefore, two processes take place on the positive surfaces
during the electrolysis.
Primarily the ionazation of the anode metal and,
Secondarily, the reformation of the ions in the form of insoluble, or not easily
soluble oxydes upon the surface of the metal.
On the negative surfaces also two processes take place.
Primarily, the separation of alkalis and earth alkalis on the surfaces of the
metal, and
Secondarily, the decomposition of H₂O and reformation of the caustic lyes, H
becoming nascent.
After about 8 days the poles are interchanged that is to say, the current is
reversed, so that a c and e then represent the negative and b and d the positive
pole. The latter then, of course, go through the corresponding part of the
process described above, while on the negative surfaces the H which becomes
nascent reduces before escaping the layers of oxyde to freely divided Pb.
After further 6 days the electrolysis is discontinued, so that then b and d on the
one hand are encrusted in layers of oxyde and a c and e on the other with layers
of divided lead.
Within the period of formation of about 8 + 6 days described I am at liberty
to interchange the poles 3 times instead of once, and thus divide the period of

page_text: formation into 4 + 3 and 4 + 3 days. Doing so results in considerable
economy of force, but also in greatly reducing the quantity of PbO, in the layers
of oxyde, and thereby correspondingly increasing that of Pb(OH)2.
The period of formation can be shortened at will, for instance, to +3 days
as in electrodes with specially large surfaces the formation is generally not so
deep. It is also always possible to somewhat decrease and even increase the
intensity of the process, by using in the mixture of the electrolyte instead of
the 20 chc. cmtrs. mentioned, 25 cbc. cmtrs. or only 15 cbc. omtrs. respectively.
The loosening of the leaden plates for the purpose of storing current has thus
been accomplished; they are, therefore taken from the bath and prepared for use
as electrodes in an accumulator-cell containing for instance, as electrolyte, diluted
aqueous sulphuric acid H₂SO, of the best possible conducting capacity.
The spongy lead plates a c and e are immediately lixiviated in water, after which
it is best to press them between india-rubber rollers to remove superfluous water,
and then they are placed as negative pole-plates in the accumulator-cell.
The oxyde-plates b and d however, it is advisable to subject as positive pole-
plates at least 24 or 48 hours, to electrolysis in diluted aqueous solution of car-
bonate of potassium, K,CO, of best possible conducting capacity with a current
of 3 amperes, in order to convert the lower stages of oxidation especially Pb(OH),
more thoroughly into PbOg. The peroxide plates are then also lixiviated in water,
and introduced into the accumulator cell, after the superfluous water has run off,
as positive pole plates.
If desired the accumulator-cell can be completely fitted with spongy lead plates.
For this purpose the spongy lead plates a cand e are replaced, after the formation
process has been completed by fresh, polished electrodes of the same material. The
latter are then subjected to electrolysis, whereby at the same time the oxyde
layers on b and d are reduced. After the process of converting into spongy lead
b and d are treated in the same manner as a cand e and then used as positive
pole-plates in the accumulator cell. The first time the latter is charged the spongy
lead of b and d is converted into PbO.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:-
The method for rendering metals capable of storing electricity by subjecting them
in shapes suitable for electrodes to the electrolysis of aqueous solutions of the
alkaline hydroxydes and the alkaline earthy hydroxydes, such solutions being
strongly diluted so that a very high degree of electrolytic dissociation of the
dissolved constituents takes place, all substantially as described and illustrated for
the purposes set forth.