IMPROVEMENTS IN THE MANUFACTURE OF ELEMENTS FOR VOLTAIC BATTERIES
Year: 1885

page_text: This Specification was, upon the 24th day of May, 1890, Amended under™
Sections 18 to 21 of the Patents; Designs, and Trade Marks Act, 1883. _.
-
°
Batteries.
I DESMOND GERALD FITZ GERALD 6 Akerman Road, Brixton in the County.
of Surrey, Electrician do hereby declare the nature of the said invention for,
IMPROVEMENTS IN THE MANUFACTURE OF ELEMENTS FOR VOLTAIC BATTERIES,
to be as follows:-
My Invention consists in improvements in the manufacture of plates or elements
for primary and for secondary voltaic batteries.
My invention has for its object, first, the production of dense and coherent
masses (moulded to any desired form) mainly composed of Oxide of lead and which
masses are either to be reduced to porous metallic lead or converted into conductive
peroxide of lead, for use as elements in voltaic batteries.
The invention has for its object, secondly, to produce by chemical action a
superficial coating of peroxide upon the whole or any portion of the masses to be
converted into negative elements-whereby the masses can in some cases be used
at once without further preparation by charging or whereby the operation of
conversion into peroxide of lead by electrolysis is greatly facilitated.
"
In carrying out this part of my Invention I take an oxide of lead preferably the
monoxide (litharge) for the production both of the positive and the negative
elements of the battery. With this material I form a plastic mass by mixing it.
with a solution that will effect a more or less gradual chemical change in the
litharge and so cause it to set and to assume a dense and coherent condition.
The solutions I prefer to use for this purpose are those of aminonic chloride,'
sulphate, carbonate, chromate, or phosphate; sodic or potassic chloride, sulphate or
chromate or of an alkaline silicate or hypochlorite. With a view to further
increase the hardness of the plates or elements, I prefer to add to the plastic mass
a certain proportion of very finely divided lead in a moist condition.
I then place
portion of the plastic mass in a mould of suitable form and apply pressure to
consolidate the mass. Plates, cylinders, &c, may thus be produced, which, when
dried by heat, or simply by exposure to the air, become very hard and coherent.
With a view to increase the porosity and strength of the elements, I usually incor-
porate with the plastic mass, before making up the element, a quantity of fibrous
asbestos, for which gun-cotton, slag-wool, or other substances possessing a sufficient

page_text: degree of chemical inalterability, may be substituted. The asbestos may take the
form of a loose open fabric embedded in the plastic material.
In the manufacture of positive elements (ie elements corresponding to the zine
in an ordinary voltaic couple) I simply maintain the plate or cylinder, produced as
above described, in contact with a cathode surface in an electrolytic cell, or in
contact with a plate of zine (preferably amalgamated) immersed in a suitable
electrolyte such as dilute sulphuric acid.
I thus obtain coherent masses of porous metallic lead of any form suitable for
the positive element of a primary or secondary voltaic battery. In the case of a
secondary battery a slab of the material mounted in a suitable conducting support
preferably of lead, or having embedded in it a tang or wire of this metal, or of
platinum, may be employed prior to the reduction of the compound to the metallic
form, as the cathode (in charging) of the battery.
In the manufacture of negative elements (i.c. elements corresponding to the
copper or carbon in an ordinary voltaic couple) the plate or cylinder produced, as
above described, may simply be maintained in contact with an anode surface (e.g a
plate or strips of lead supporting and partly enveloping the plate or cylinder of
coherent lead compound) within an electrolytic cell.
The lead compound is thus gradually converted into dense and conductive
peroxide of lead constituting an admirable negative element. But in the produc-
tion of negative elements (or anodes in charging in the case of secondary batteries)
I prefer, even when peroxide of lead is to be obtained by electrolysis, to subject the
plate or cylinder of lead compound (consisting mainly of lead oxide) to the action
of chlorine, or of an earthy or alkaline hypochlorite, so as, by this means, to coat
the whole of a portion of the surface with a conductive layer of peroxide of lead.
Plates so coated, or a number of them placed together so as to be in conductive
contact with each other at one or more points, but without having the greater
portion of their surfaces in absolute contact, may be used as negative elements
without any further preparation by "charging" in an electrolytic cell.
To obtain an efficient and permanent contact with the peroxide of lead negative
element, I sometimes embed a platinum wire or strip in the plastic material of
which the element is manufactured. But in the case more especially of elements
of large dimensions, I prefer to obtain contact by clamping a strip of thin lead or
lead antimony alloy to a portion of the peroxide element which has been rendered
impervious to fluid by immersion in melted paraffin-wax, the excess of which is
afterwards carefully removed so as to expose a conductive surface of peroxide.
The negative elements should be perforated in order to facilitate the peroxidation
of the material and also to facilitate the voltaic action when the element is in use.
The perforations should be made in a mould of convenient form and when the
material is in a plastic state, I effect this by means of a plate provided with conical
pins which is supported on indiarubber blocks just above but not touching the
mass to be perforated. Pressure is applied to, the plate so as to cause the conical
pins to perforate the mass, the indiarubber supports yielding under the pressure
and then instantly withdrawing the pins.
To avoid adherence of the material to the mould and to enable the mass to be
removed without difficulty, a layer of some suitable fabric should be placed in the
mould before the introduction of the material.
Dated thin 12th
t A 1 1000

page_text: COMPLETE SPECIFICATION (AMENDED).
Improvements in the Manufacture of Elements for Voltaic
Batteries.
I DESMOND GERALD FITZ GERALD, of 6 Akerman Road Brixton in the County
of Surrey, Electrician, 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 Invention consists in improvements in the manufacture of plates or elements
to be used in voltaic batteries, and more especially in secondary batteries. It has
for its object, in the first place, the production of plates, layers, or masses, mainly
composed of oxide of lead in a dense and coherent form, such plates, layers, or
masses, being subsequently either reduced to the condition of porous metallic lead,
or converted into a highly conductive form of per-oxide of lead, (which from its
hardness, and the fact of its being produced at the positive pole in electrolysis
I term lithanode) with a view to their constituting the positive and negative
elements of a secondary, (or primary) voltaic battery.
In carrying out this part of my Invention, I take an oxide of lead, other than
the peroxide (preferably the monoxide in the form of litharge) and I bring it into
admixture with a solution which (after the plastic mass thus produced has been
moulded into the required form, or has been applied as a layer upon any given
surface) will effect a partial, and more or less gradual, chemical change in the oxidé,
and so cause it to "set," and to assume a dense and coherent condition, permitting
of the substance being handled, and being immersed in a fluid without falling to
pieces. The solution I prefer to use for this purpose is that of a salt constituted
by ammonia as a base, in combination with an acid which, (when set free by
decomposition of the ammonia salt,) will combine with the oxide of lead, and form
an insoluble, or nearly insoluble compound of lead. Such salts are the sulphate,
phosphate, chromate, tartrate, oxalate, borate, and sesqui-carbonate, of ammonia,
and the chloride of ammonium. But any salt (such as hydro-potassic, or hydro-
sodic, sulphate; potassic, or sodic, sulphate, chloride, or chromate) which becomes
wholly, or partly, decomposed by oxide of lead, producing an insoluble, or nearly
insoluble, compound of this metal, will more or less perfectly answer the purpose
in view; viz the production of a coherent plate, or mass, mainly composed of
oxide of lead. The use of a chloride, and also the treatment of the moulded plates
with chlorine, hereafter referred to, are sometimes to be avoided, (in view of the
possibility of evolving chlorine in the operation of "charging" the element as
anode) unless the chloride of lead which is formed be removed by washing the
plate in hot water.
I will now proceed to give examples of the modes in which I carry out this
portion of my Invention. Commencing with the manufacture of rectangular plates,
say 4 x 7 inches, and from 13 to about 2 inch in thickness, to be made the anodes

page_text: in the electrolytic process of " charging," or otherwise converted into negative
elements employ a frame or mould of dimensions corresponding to those above
given, such as that represented in Figures 1. and 1ª of the accompanying drawings
where A. B. C. and D. are separate strips which, when fixed by dowel-pins a a on
a base block E make up a frame or mould for the production of the plates. Such
frame is slightly undercut or bevelled on the inner edge in order to facilitate the
subsequent removal of the frame from the plastic mass. The base block is first.
covered with a piece of moistened cotton-cloth having holes corresponding to the
pins a a, and the sides of the frame are then placed in position. The mould being
tbus in readiness, I take from 10 to 17 ounces of litharge, according to the required
thickness of the plate, which is determined by that of the frame-pieces, and as
rapidly as possible mix it with a half saturated solution of sulphate of ammonia,
sufficient in quantity to convert the litharge into a pasty mass. This mass, by
means of a spatula, or small trowel, is spread evenly within the framic. It is then
covered with a piece of moistened fabric on which is placed a piece of felt, and
upon this another block of wood, extending at least as far as the outside of the
frame, and the whole then subjected to pressure in a hydraulic, or ordinary screw
.press.
With a view to increase the porosity of the elements I may incorporate with the
plastic mass a quantity of fibrous asbestos, slag-wool, roughly powdered earthen-
ware, or pumice, or other substances adapted for the purpose in view, and possessing
a sufficient degree of chemical inalterability. Such substances, however, if they be
employed, should be used sparingly, as they diminish the conductivity, and con-
sequently the efficiency, of the elements, and those portions of the elements at
which contact is made to effect the charge, or discharge of the element, should, in
all cases, be freed from the inert, and badly conducting substances in question.
After the compression of the plastic mass, the top-block, the felt, the fabric, and the
pieces A. B. C. and D. are removed, and the moulded plate is then covered with a
piece of dry fabric upon which I place a slab, preferably of porous and perforated
earthenware, and then invert the whole. The base block, and the piece of fabric
which was laid on it in the first instance, may then be successively removed from
the plate. I then place another slab of porous earthernware directly upon the plate
and again invert it. I then successively remove the first porous slab and piece of
dry fabric, leaving the plate, already partly set," upon the naked porous slab, in
which condition it may be put aside to dry. Plates so produced become, in a few
days, very hard and colierent; will stand handling; and have no tendency to
disintegrate when immersed in water, or in a neutral aqueous solution such as that
of magnesia-sulphate.
1 th
A modification of the above process for the manufacture of negative elements
consists in mixing the dry litharge with about 2 of its weight of the ammonia
salt, also in a dry state, which admixture may be effected by grinding the materials
together. The mixture is then spread uniformly within the frame A. B. C. D. before.
described upon a piece of cotton fabric. It is then subjected to compression in the
manner before described whilst still in the dry state, and, lastly, the pulverulent
mixture is thoroughly moistened by means of water-spray, or steam (which has the
effect of consolidating the surface) followed by the spray. When the mixture has
set sufficiently the plate may be removed from the mould and set aside to dry in
a warm atmosphere upon a slab of porous material, as in the previous case. By
inserting in the base block, within the frame, a number of slightly conical pins
corresponding in height with the intended thickness of the plate the latter may he
moulded with any required number of perforations; these being necessary in the
case of compound elements built up of a number of plates with a view to obtain a
high rate of discharge.
*6
have entered thus minutely into the description of the modus operandi, in
consequence of the difficulty in manipulating the freshly prepared material, but
I do not in any way limit myself to the details of procedure here given.
:

page_text: .
Passing now to the manufacture of plates to be made the cathodes in the
electrolytic process of "charging"; such plates may be similar to those above
described but less in thickness. In this case the plate should preferably be
mounted in a frame of lead which is itself fitted within a frame of teak wood, or
other, suitable material, the light lead frame being provided with tangs which are
soldered to a conductor dipping into a mercury trough, or otherwise disposed for
the charge or discharge of the element. But I prefer, generally, to construct the
positive elements by coating with a plastic mass of lead oxide (such as that
produced with litbarge and ammonic sulphate solution when freshly mixed as
above described) plates of thin sheet lead preferably perforated or roughened and
having a conducting wire or tang w soldered or otherwise attached which serves to
support the element as shown in Figure 2. Plates so coated may, before the plastic
material has "set," be subjected to pressure between two sheets of felt, a rough
cotton, or other fabric, being interposed between the coated plate and the felt, to
prevent adhesion to the latter of the plastic material. Or instead of coating a
plate, a strip, or strips, of lead may be embedded in the plastic mass whilst in the
mould for the purpose of obtaining contact with the element. Or plates or masses
of the lead-oxide, after the same has been caused to "set" as above described, may
be placed on, or otherwise held in contact with, a cathode surface (which may be of
lead) in an electrolytic tank. I prefer to effect the reduction of the reducible
material into porous metallic lead by making the plates last described the cathodes
in an electrolytic tank containing a solution of sulphate of magnesia as the
electrolyte, the plates first herein described being the anodes in the tank. But
many other electrolytes (eg: a solution of sulphate of ammonia, or of sulphate
of soda) will answer the required purpose. The plates thus converted into porous
lead positive elements should be afterwards immersed in water to protect them
from oxidation until they are required for use; they are then ordinarily arranged
in a battery trough containing an electrolyte of dilute sulphuric acid.
27
The weight of active material (oxide of lead) employed in the manufacture of
the positive (porous lead) element should be about half that employed in making
up the negative (peroxide) element. The minimum effective "charging" capacity
of the positive element has been roughly estimated in practice to be two ampère
hours per ounce avoirdupois of oxide of lead used in the construction of the element;
whereas the minimum effective "charging" capacity of the negative element is
estimated to be one ampère hour per ounce of litharge used. It will be understood
that the effective "charging" capacity here referred to is measured by the product
of the current generated under a high electromotive force into the time during
which such current passes; the capacity, as measured by the total discharge of the
element, being very much greater than that above stated.
Reverting now to the plates intended for conversion into negativo elements, these
may simply be applied to a supporting anode surface of lead inclined at an angle
of 50° to 60° from the horizontal, and furnished with a ledge of non-conducting
material upon which rest the lower edges of the plates. But I prefer to perforate
the plates with two holes as shown in Figure 3 and to clamp to them strips of
lead of which one side (the outer) has been protected by a varnish or coating of
insulating cement, and the other side (to be in contact with the plate) has been
superficially coated with peroxide of lead by electrolysis in dilute sulphuric acid.
The strips are attached to the plates by means of screws and nuts of vulcanite or
other suitable non-oxidizable material. Or, as in Figures 4 and 5 instead of the
strips of lead, strips of ebonite (vulcanite) to the under-surfaces of which two or
more strips p p of platinum are cemented, which strips are in electrical contact
with a conductor wo (protected by insulating material except at the bent down
extremity) serving to support the element within the tank or trough, may be
clamped to the plates by means of ebonite screws and nuts, the ebonite strip being
firmly attached to the conductor w w in order to prevent any strain upon the
platinum strips. When the plates are large they may be further supported near

page_text: each end by means of two strips of vulcanite or other suitable material attached
to w w and bent up or hooked at their lower extremity so as to embrace the lower
edge of the plate. But in supporting the plate care must in all cases be taken
to allow free expansion and contraction; a rigid attachment being, strictly speaking,
allowable only at one point of the plate. Neglect of this precaution (as for instance
confining the plate within a closely-fitting frame) may result in warping, exfoliation,
and disintegration of the element by the effect of expansion and contraction in
charge and discharge; whereas if expansion can take place freely the element will
last in perfect condition for an indefinite period. The plates so mounted are
suspended between two cathodes (usually the cathode plates previously described)
in an electrolytic tank or in a battery-trough, containing in the first place a neutral
:solution such as a solution of sulphate of magnesia about half saturated, or
solution of sulphate of soda, or sulphate of ammonia. The plates ordinarily
require to be charged and discharged several times before they are sufficiently
"formed" or converted into peroxide of lead. After the first or second charge the
electrolyte employed may be a dilute solution of sulphuric acid. According to
the degree of porosity of the plate the number of charges in acid (subsequent to
the preliminary charge in the sulphate of magnesia solution) which are necessary
to "form" the plate varies from 2 to 6, the less porous plates taking the longer
time to effect the conversion. The plates should be somewhat slowly discharged
after each charge, excepting the last.
a
Before proceeding to effect the electrolytic conversion into peroxide of lead of
the plates of lead oxide, I prefer in most cases to superficially peroxidize them by
chemical means, viz-by the oxidizing action of chlorine in the presence of water
.as hereinafter described. The elements thus produced may even, in some cases, be
used in a battery without the employment of the electrolytic means of conversion.
al
My Invention has therefore for its object, secondly, the production of this more
or less superficial coating of peroxide of lead upon plates or concreted masses
-mainly composed of oxide of lead which are to be converted into negative elements
for use in a secondary or primary battery. The most convenient form in which
chlorine can be utilized for the purpose in view, is in its combination as
hypochlorite, but the use of calcic hypochlorite (chloride of lime) is objectionable
by reason of the difficulty of obviating the production, within the pores, and on
the surface of the plates when the same are made up into a battery with a sulphuric
acid electrolyte, of sulphate of lime, a salt which is practically insoluble, and which
is formed by the decomposition of any calcic chloride remaining in the plate, and
also from lime deposited on the plate as carbonate. I therefore prefer to uso
chloride of soda (sodic hypochlorite) or chloride of magnesia (magnesic hypo-
chlorite) which may be obtained by decomposing a solution of chloride of lime by
means of sodic carbonate, or magnesic sulphate. But in operating on a large scale,
I economically generate and utilize the magnesic bypo-chlorite as follows; I pass
chlorine gas into the lower part of a tank containing hot water in which the plates
to be converted are supported, preferably edgeways, and at a small distance apart.
"The plates preferably rest on a perforated false bottom beneath which is placed a
quantity of calcined magnesite, or other form of magnesia in powder, into the midst
of which the chlorine is introduced by perforated stoneware tubes, or other suitable
means. The tank and false bottom are preferably made of stoneware or slate.
The magnesia gradually becomes dissolved by reason of its conversion into hypo-
-chlorite, and chloride of magnesium. It is necessary that the operation should not
be continued after the magnesia is wholly dissolved without adding a fresh supply.
Heat may be applied by blowing in steam, and the hot solution of magnesic
hypochlorite effects a rapid and more or less superficial conversion of the surface
of the plates into peroxide of lead, the depth of the conversion increasing with the
porosity of the plates. Plates made up with certain solutions, (e.g. ammonic
phosphate) are so fragile prior to undergoing this process of superficial peroxidiza-
tion that it is desirable not to remove them from the plates of perforate earthenware

page_text: upon which they were placed to dry, but to arrange them horizontally on these
same plates within the chlorine tank; the perforated plates being superposed and-
separated by pieces of earthenware placed between them near their edges.
It is.
sometimes desirable to peroxidize one side only of the plates, which in this case
may be. laid upon panes of glass similarly superposed and separated, whereby
the lower sides of the plates are protected from the action of the solution.
Plates thus superficially peroxidized, or "browned," may be electrolytically
"formed
or converted in the same way as previously described for plates which.
are not "browned."
"
In regard to the means for establishing effective contact with the plates when
they are made up into a battery, it may be stated that small positive elements for
experimental purposes may have a small piece of thin sheet lead folded over their
upper edge to which a binding screw is clamped; and small "lithanode or negative
plates may have a piece of platinum foil over one of their edges. Or, in either
case, the upper edge of the plate may be immersed in melted paraffin-wax, which.
is subsequently scraped from the surface so as to expose the conducting material
and thus to allow of an effective contact being made by a binding-screw which
will, by this means, be protected from the acid electrolyte rising in the plate by
capilliary action. Í, however, prefer the system (shown in Figure 2) of using a
lead support in the case of the positive element, this system being equally applicable
for large positive elements. I sometimes embed in small negative elements a piece
of platinum wire the embedded portion of which has been beaten to a flattened and
irregular form. Or, I construct such small elements with a groove in the edges of
a plate, or around the upper part of a cylinder, in which groove is placed a lead
wire which encircles wholly or partially the element, and may be soldered at its.
ends to a supporting wire. This lead wire in the preparation of the plate becomes.
superficially converted into peroxide of lead, and the portion of the plate around
which the wire is applied being subsequently immersed in melted paraffin-wax the
wire is protected from contact with the electrolyte, and therefor from
"local
action." The contact by means of a strip of lead, as shown in Figure 3, is not well
adapted for the discharge of the negative (lithanode), plate when the latter forms
a portion of a battery, and on the other hand, a thin strip, frame, or other contact.
of dense carbon, although suitable for discharge, speedily disintegrates if employed
for charging the plate. The contact piece shown in Figure 4. is well adapted both
for discharging the negative plate and also for charging it, provided care be taken
to avoid overcharging the cleinent, or to remove chloride of lead from the element
by washing with hot water as the evolution of chlorine gas- would, in course of
time, have the effect of destroying the platinum strips.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed; I would observe
that I do not claim the specific method of applying steam to the dry mixture of
oxide of lead and a salt, as such method forms the subject of another application
for Letters Patent, and I declare that what I claim is ;-
1. The herein described process of producing dense and coherent plates, masses,
or layers, mainly composed of oxide of lead, which process consists in the admixture
with the oxide of lead of a soluble salt, which when brought by solution into
chemical contact with the oxide of lead will become decomposed and form with the
oxide of lead an insoluble salt of this metal and thus cause the material to
and acquire the required dense and coherent condition.
set."
2. In the process of producing dense and coherent plates, or concreted masses or
layers of oxide of lead, the combination with a portion of the lead entering into
the composition of such plates, masses, or layers, of the acid radical of an animonia
salt, the salt being such that its radical will form with lead an insoluble, or nearly
insoluble, salt of that metal, the object of such combination being to cause the
material of which the plate, mass, or layer is formed to "set" so that it will not
disintegrate when subsequently immersed in water."

page_text: 3. The herein described-process of peroxidizing plates, or masses, of oxide of lead
which has been-enused to set "as herein described, by submitting them to the
oxidizing nation of chlorine in the presence of water, substantially as-specified.
43. The herein described process of peroxidizing plates or masses of oxide of load
by submitting them to the oxidizing action of a hot aqueous solution of sodic or 5
magnesic hypochlorite; substantially as specified.
Dal
LL. 1005
DESMOND G. FITZ GERALD.
By A. M. & W Clark, Agents.

page_text: I DESMOND GERALD FITZ GERALD 6 Akerman Road, Brixton in the County
of Surrey, Electrician do hereby declare the nature of the said invention for
IMPROVEMENTS IN THE MANUFACTURE OF ELEMENTS FOR VOLTAIC BATTERIES,
to be as follows:-
My Invention consists in improvements in the manufacture of plates or elements
for primary and for secondary voltaic batteries.
My invention has for its object, first, the production of dense and coherent
masses (moulded to any desired form) mainly composed of Oxide of lead and which
masses are either to be reduced to porous metallic lead or converted into conductive
peroxide of lead, for use as elements in voltaic batteries.
The invention has for its object, secondly, to produce by chemical action a
superficial coating of peroxide upon the whole or any portion of the masses to be.
converted into negative elements-whereby the masses can in some cases be used
at once without further preparation by charging or whereby the operation of
conversion into peroxide of lead by electrolysis is greatly facilitated.
In carrying out this part of my Invention I take an oxide of lead preferably the
monoxide (litharge) for the production both of the positive and the negative
elements of the battery. With this material I form a plastic mass by mixing it
with a solution that will effect a more or less gradual chemical change in the
litharge and so cause it to "set" and to assume a dense and coherent condition.
The solutions I prefer to use for this purpose are those of ammonic chloride,
sulphate, carbonate, chromate, or phosphate; sodic or potassic chloride, sulphate or
chromate or of an alkaline silicate or hypochlorite. With a view to further
increase the hardness of the plates or elements, I prefer to add to the plastic mass
a certain proportion of very finely divided lead in a moist condition. I then place
a portion of the plastic mass in a mould of suitable form and apply pressure to
consolidate the mass. Plates, cylinders, &, may thus be produced, which, when
dried by heat, or simply by exposure to the air, become very hard and coherent.
With a view to increase the porosity and strength of the elements, I usually incor-
porate with the plastic mass, before making up the element, a quantity of fibrous
asbestos, for which gun-cotton, slag-wool, or other substances possessing a sufficient ⚫

page_text: degree of chemical inalterability, may be substituted. The asbestos may take the
form of a loose open fabric embedded in the plastic material.
In the manufacture of positive elements (i e elements corresponding to the zinc
in an ordinary voltaic couple) I simply maintain the plate or cylinder, produced as
above described, in contact with a cathode surface in an electrolytic cell, or in
contact with a plate of zinc (preferably amalgamated) immersed in a suitable
electrolyte such as dilute sulphuric acid.
I thus obtain coherent masses of porous metallic lead of any form suitable for
the positive element of a primary or secondary voltaic battery. In the case of a
secondary battery a slab of the material mounted in a suitable conducting support
preferably of lead, or having embedded' in 'it a tang or wire of this metal, or of
platinum, may be employed prior to the reduction of the compound to the metallic
form, as the cathode (in charging) of the battery.
In the manufacture of negative elements (i.e. elements corresponding to the
copper or carbon in an ordinary voltaic couple) the plate or cylinder produced, as
above described, may simply be maintained in contact with an anode surface (e.g a
plate or strips of lead supporting and partly enveloping the plate or cylinder of
coherent lead compound) within an electrolytic cell.
The lead compound is thus gradually converted into dense and conductive
peroxide of lead constituting an admirable negative element. But in the produc-
tion of negative elements (or anodes in charging in the case of secondary batteries)
I prefer, even when peroxide of lead is to be obtained by electrolysis, to subject the
plate or cylinder of lead compound (consisting mainly of lead oxide) to the action
of chlorine, or of an earthy or alkaline hypochlorite, so as, by this means, to coat.
the whole of a portion of the surface with a conductive layer of peroxide of lead.
Plates so coated, or a number of them placed together so as to be in conductive
contact with each other at one or more points, but without having the greater
portion of their surfaces in absolute contact, may be used as negative clements
without any further preparation by "charging" in an electrolytic cell.
To obtain an efficient and permanent contact with the peroxide of lead negative
element, I sometimes embed a platinum wire or strip in the plastic material of
which the element is manufactured. But in the case more especially of elements
of large dimensions, I prefer to obtain contact by clamping a strip of thin lead or
lead antimony alloy to a portion of the peroxide element which has been rendered
impervious to fluid by immersion in melted paraffin-wax, the excess of which is
afterwards carefully removed so as to expose a conductive surface of peroxide.
The negative elements should be perforated in order to facilitate the peroxidation
of the material and also to facilitate the voltaic action when the element is in use.
The perforations should be made in a mould of convenient form and when the
material is in a plastic state, I effect this by means of a plate provided with conical
pins which is supported on indiarubber blocks just above but not touching the
mass to be perforated. Pressure is applied to the plate so as to cause the conical
pins to perforate the mass, the indiarubber supports yielding under the pressure
and then instantly withdrawing the pins.
To avoid adherence of the material to the mould and to enable the mass to be
removed without difficulty, a layer of some suitable fabric should be placed in the
mould before the introduction of the material.

page_text: I DESMOND GERALD FITZ GERALD, of 6 Akerman Road Brixton in the County
of Surrey, Electrician, 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 Invention consists in improvements in the manufacture of plates or elements
to be used in voltaic batteries, and more especially in secondary batteries. It has
for its object, in the first place, the production of plates, layers, or masses, mainly
composed of oxide of lead in a dense and coherent form, such plates, layers, or
masses, being subsequently either reduced to the condition of porous metallic lead,
or converted into a highly conductive form of per-oxide of lead, (which from its
liardness, and the fact of its being produced at the positive pole in electrolysis
I term lithanode) with a view to their constituting the positive and negative
elements of a secondary, (or primary) voltaic battery.
In carrying out this part of my Invention, I take an oxide of lead, other than
the peroxide (preferably the monoxide in the form of litharge) and I bring it into
admixture with a solution which (after the plastic mass thus produced has been
moulded into the required form, or has been applied as a layer upon any given
surface) will effect a partial, and more or less gradual, chemical change in the oxide,
and so cause it to "set," and to assume a dense and coherent condition, permitting
of the substance being handled, and being immersed in a fluid without falling to
pieces. The solution I prefer to use for this purpose is that of a salt constituted
by ammonia as a base, in combination with an acid which, (when set free by
decomposition of the ammonia salt,) will combine with the oxide of lead, and form
an insoluble, or nearly insoluble compound of lead. Such salts are the sulphate,
phosphate, chromate, tartrate, oxalate, borate, and sesqui-carbonate, of ainmonia,
and the chloride of ammonium. But any salt (such as hydro-potassic, or hydro-
sodic, sulphate; potassic, or sodic, sulphate, chloride, or chromate) which becomes
wholly, or partly, decomposed by oxide of lead, producing an insoluble, or nearly
insoluble, compound of this metal, will more or less perfectly answer the purpose
in view; viz the production of a coherent plate, or mass, mainly composed of
oxide of lead. The use of a chloride, and also the treatment of the moulded plates
with chlorine, hereafter referred to, are sometimes to be avoided, (in view of the
possibility of evolving chlorine in the operation of "charging" the element as
anode) unless the chloride of lead which is formed be removed by washing the
plate in hot water.
I will now proceed to give examples of the modes in which I carry out this
portion of my Invention. Commencing with the manufacture of rectangular plates,
say 4 x 7 inches, and from 13 to about 2 inch in thickness, to be made the anodes

page_text: in the electrolytic process of "charging," or otherwise converted into negative
elements-I employ a frame or mould of dimensions corresponding to those above
given, such as that represented in Figures 1. and 1° of the accompanying drawings
where A. B. C. and D. are separate strips which, when fixed by dowel-pins a a on
a base block E make up a frame or mould for the production of the plates. Súch
frame is slightly undercut or bevelled on the inner edge in order to facilitate the
subsequent removal of the frame from the plastic mass. The base block is first
covered with a piece of moistened cotton-cloth baving holes corresponding to the
pins a a, and the sides of the frame are then placed in position. The mould being
thus in readiness, I take from 10 to 17 ounces of litharge, according to the required
thickness of the plate, which is determined by that of the frame-pieces, and as
rapidly as possible mix it with a half saturated solution of sulphate of ammonia,
sufficient in quantity to convert the litharge into a pasty mass.
This mass, by
means of a spatula, or small trowel, is spread evenly within the frame. It is then
covered with a piece of moistened fabric on which is placed a piece of felt, and
upon this another block of wood, extending at least as far as the outside of the
frame, and the whole then subjected to pressure in a hydraulic, or ordinary screw
press.
With a view to increase the porosity of the elements I may incorporate with the
plastic mass a quantity of fibrous asbestos, slag-wool, roughly powdered earthen-
ware, or pumice, or other substances adapted for the purpose in view, and possessing
a sufficient degree of chemical inalterability. Such substances, however, if they be
employed, should be used sparingly, as they diminish the conductivity, and con-
sequently the efficiency, of the elements, and those portions of the elements at
which contact is made to effect the charge, or discharge of the element, should, in
all cases, be freed from the inert, and badly conducting substances in question.
After the compression of the plastic mass, the top-block, the felt, the fabric, and the
pieces A. B. C. and D. are removed, and the moulded plate is then covered with a
piece of dry fabric upon which I place a slab, preferably of porous and perforated
earthenware, and then invert the whole. The base block, and the piece of fabric
which was laid on it in the first instance, may then be successively removed from
the plate. I then place another slab of porous earthenware directly upon the plate
and again invert it. I then successively remove the first porous slab and piece of
dry fabric, leaving the plate, already partly "set," upon the naked porous slab, in
which condition it may be put aside to dry. Plates so produced become, in a few
days, very hard and coherent; will stand handling; and have no tendency to
disintegrate when immersed in water, or in a neutral aqueous solution such as that
of magnesia-sulphate.
A modification of the above process for the manufacture of negative elements
consists in mixing the dry litharge with about th of its weight of the ammonia
salt, also in a dry state, which admixture may be effected by grinding the materials
together. The mixture is then spread uniformly within the frame A. B. C. D. before
described upon a piece of cotton fabric. It is then subjected to compression in the
manner before described whilst still in the dry state, and, lastly, the pulverulent
mixture is thoroughly moistened by means of water-spray, or steam (which has the
effect of consolidating the surface) followed by the spray. When the mixture has
"set sufficiently the plate may be removed from the mould and set aside to dry in
a warm atmosphere upon a slab of porous material, as in the previous case. By
inserting in the base block, within the frame, a number of slightly conical pins
corresponding in height with the intended thickness of the plate the latter may be
moulded with any required number of perforations; these being necessary in the
case of compound elements built up of a number of plates with a view to obtain a
high rate of discharge.
I have entered thus minutely into the description of the modus operandi, in
consequence of the difficulty in manipulating the freshly prepared material, but
I do not in any way limit myself to the details of procedure here given.

page_text: Passing now to the manufacture of plates to be made the cathodes in the
electrolytic process of "charging"; such plates may be similar to those above
described but less in thickness. In this case the plate should preferably be
mounted in a frame of lead which is itself fitted within a frame of teak wood, or
other suitable material, the light lead frame being provided with tangs which are
soldered to a conductor dipping into a mercury trough, or otherwise disposed for
the charge or discharge of the element. But I prefer, generally, to construct the
positive elements by coating with a plastic mass of lead oxide (such as that
produced with litharge and ammonic sulphate solution when freshly mixed as
above described) plates of thin sheet lead preferably perforated or roughened and
having a conducting wire or tang w soldered or otherwise attached which serves to
support the element as shown in Figure 2. Plates so coated may, before the plastic
material has "set," be subjected to pressure between two sheets of felt, a rough
cotton, or other fabric, being interposed between the coated plate and the felt, to
prevent adhesion to the latter of the plastic material. Or instead of coating a
plate, a strip, or strips, of lead may be embedded in the plastic mass whilst in the
mould for the purpose of obtaining contact with the element. Or plates or masses
of the lead-oxide, after the same has been caused to "set" as above described, may
be placed on, or otherwise held in contact with, a cathode surface (which may be of
lead) in an electrolytic tank. I prefer to effect the reduction of the reducible
material into porous metallic lead by making the plates last described the cathodes
in an electrolytic tank containing a solution of sulphate of magnesia as the
electrolyte, the plates first herein described being the anodes in the tank. But
many other electrolytes (e: g: a solution of sulphate of ammonia, or of sulphate
of soda) will answer the required purpose. The plates thus converted into porous
lead positive elements should be afterwards immersed in water to protect them
from oxidation until they are required for use; they are then ordinarily arranged
in a battery trough containing an electrolyte of dilute sulphuric acid.
The weight of active material (oxide of lead) employed in the manufacture of
the positive (porous lead) element should be about half that employed in making
up the negative (peroxide) element. The minimum effective "charging" capacity
of the positive element has been roughly estimated in practice to be two ampère
hours per ounce avoirdupois of oxide of lead used in the construction of the element;
whereas the minimum effective " charging" capacity of the negative element is
estimated to be one ampère hour per ounce of litharge used. It will be understood
that the effective "charging" capacity here referred to is measured by the product
of the current generated under a high electromotive force into the time during
which such current passes; the capacity, as measured by the total discharge of the
element, being very much greater than that above stated.
Reverting now to the plates intended for conversion into negative elements, these
may simply be applied to a supporting anode surface of lead inclined at an angle
of 50° to 60° from the horizontal, and furnished with a ledge of non-conducting
material upon which rest the lower edges of the plates. But I prefer to perforate
the plates with two holes as shown in Figure 3 and to clamp to them strips of
leads of which one side (the outer) has been protected by a varnish or coating of
insulating cement, and the other side (to be in contact with the plate) has been
superficially coated with peroxide of lead by electrolysis in dilute sulphuric acid.
The strips are attached to the plates by means of screws and nuts of vulcanite or
other suitable non-oxidizable material. Or, as in Figures 4 and 5 instead of the
strips of lead, strips of ebonite (vulcanite) to the under-surfaces of which two or
more strips p p of platinum are cemented, which strips are in electrical contact
with a conductor ww (protected by insulating material except at the bent down
extremity) serving to support the element within the tank or trough, inay be
clamped to the plates by means of ebonite screws and nuts; the ebonite strip being
firmly attached to the conductor w w in order to prevent any strain upon the
platinum strips. When the plates are large they may be further supported near

page_text: cach end by means of two strips of vulcanite or other suitable material attached
to ww and bent up or hooked at their lower extremity so as to embrace the lower
edge of the plate. But in supporting the plate care must in all cases be taken
to allow free expansion and contraction; a rigid attachment being, strictly speaking,
allowable only at one point of the plate. Neglect of this precaution (as for instance
confining the plate within a closely-fitting fraue) may result in warping, exfoliation,.
and disintegration of the element by the effect of expansion and contraction in
charge and discharge; whereas if expansion can take place freely the element will
last in perfect condition for an indefinite period. The plates so mounted are
suspended between two cathodes (usually the cathode plates previously described).
in an electrolytic tank or in a battery-trough, containing in the first place a neutral
solution such as a solution of sulphate of magnesia about half saturated, or a
solution of sulphate of soda, or sulphate of ammonia. The plates ordinarily
require to be charged and discharged several times before they are sufficiently
formed" or converted into peroxide of lead. After the first or second charge the
electrolyte employed may be a dilute solution of sulphuric acid. According to
the degree of porosity of the plate the number of charges in acid (subsequent to
the preliminary charge in the sulphate of, magnesia solution) which are necessary
to "form" the plate varies from 2 to 6, the less porous plates taking the longer
time to effect the conversion. The plates should be somewhat slowly discharged
after each charge, excepting the last.
si
Before proceeding to effect the electrolytic conversion into peroxide of lead of
the plates of lead oxide, I prefer in most cases to superficially peroxidize them by
chemical means, viz-by the oxidizing action of chlorine in the presence of water
as hereafter described The elements thus produced may even, in some cases, be
used in a battery without the employment of the electrolytic means of conversion.
My Invention has therefore for its object, secondly, the production of this more
or less superficial coating of peroxide of lead upon plates or concreted masses
mainly composed of oxide of lead which are to be converted into negative elements
for use in a secondary or primary battery. The most convenient form in which
chlorine can be utilized for the purpose in view, is in its combination as a
hypochlorite, but the use of calcic hypochlorite (chloride of lime) is objectionable
by reason of the difficulty of obviating the production, within the pores, and on
the surface of the plates when the same are made up into a battery with a sulphuric
acid electrolyte, of sulphate of lime, a salt which is practically insoluble, and which
is formed by the decomposition of any calcic chloride remaining in the plate, and
also from lime deposited on the plate as carbonate. I therefore prefer to use
chloride of soda (sodic hypochlorite) or chloride of magnesia (magnesic hypo-
chlorite) which may be obtained by decomposing a solution of chloride of lime by
means of sodic carbonate, or magnesic sulphate. But in operating on a large scale,
I economically generate and utilize the magnesic hypo-chlorite as follows;-I pass
chlorine, gas into the lower part of a tank containing hot water in which the plates
to be converted are supported, preferably edgeways, and at a small distance apart.
The plates preferably rest on a perforated false bottom beneath which is placed a
quantity of calcined magnesite, or other form of magnesia in powder, into the midst
of which the chlorine is introduced by perforated stoneware tubes, or other suitable
means. The tank and false bottom are preferably made of stoneware or slate.
The magnesia gradually becomes dissolved by reason of its conversion into hypo-
chlorite, and chloride of magnesium. It is necessary that the operation should not
be continued after the magnesia is wholly dissolved without adding a fresh supply.
Heat may be applied by blowing in steam, and the hot solution of magnesic
hypochlorite effects a rapid and more or less superficial conversion of the surface.
of the plates into peroxide of lead, the depth of the conversion increasing with the
porosity of the, plates. Plates made up with certain solutions, (e.g. ammonic
phosphate) are so fragile prior to undergoing this process of superficial peroxidiza-
tion that it is desirable not to remove them from the plates of perforated earthenware

page_text: upon which they were placed to dry, but to arrange them horizontally on these
same plates within the chlorine tank; the perforated plates being superposed and
separated by pieces of earthenware placed between them near their edges. It is
sometimes desirable.to peroxidize one side only of the plates, which in this case
may be laid upon panes of glass similarly superposed and separated, whereby
the lower sides of the plates are protected from the action of the solution.
"
:
Plates thus superficially peroxidized, or "browned," may be electrolytically.
" formed or converted in the same way as previously described for plates which
are not "browned."
"
In regard to the means for establishing effective contact with the plates when
they are made up into a battery, it may be stated that small positive elements for
experimental purposes may have a small piece of thin sheet lead folded over their
upper edge to which a binding screw is clamped; and small "lithanode or negative
plates may have a piece of platinum foil over one of their edges. Or, in either
case, the upper edge of the plate may be immersed in melted paraffin-wax, which
is subsequently scraped from the surface so as to expose the conducting material
and thus to allow of an effective contact being made by a binding-screw which
will, by this means, be protected from the acid electrolyte rising in the plate by
capillary action. I, however, prefer the system (shown in Figure 2) of using a
lead support in the case of the positive element, this system being equally applicable
for large positive elements. I sometimes embed in small negative elements a piece
of platinum wire the embedded portion of which has been beaten to a flattened and
irregular form. Or, I construct such small elements with a groove in the edges of
a plate, or around the upper part of a cylinder, in which groove is placed a lead
wire which encircles wholly or partially the element, and may be soldered at its
ends to a supporting wire. This lead wire in the preparation of the plate becomes
superficially converted into peroxide of lead, and the portion of the plate around
which the wire is applied being subsequently immersed in melted paraffin-wax the
wire is protected from contact with the electrolyte, and therefor from "local
action "
The contact by means of a strip of lead, as shown in Figure 3, is not well
adapted for the discharge of the negative, (lithanode) plate when the latter forms
a portion of a battery, and on the other hand, a thin strip, frame, or other contact
of dense carbon, although suitable for discharge, speedily disintegrates if employed
for charging the plate. The contact piece shown in Figure 4. is well adapted both
for discharging the negative plate and also for charging it, provided care be taken
to avoid overcharging the element, or to remove chloride of lead from the element
by washing with hot water as the evolution of chlorine gas would, in course of
time, have the effect of destroying the platinum strips.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed; I would observe
that I do not claim the specific method of applying steam to the dry mixture of
oxide of lead and a salt, as such method forms the subject of another application
for Letters Patent, and I declare that what I claim is;-
1. The herein described process of producing dense and colierent plates, masses,
or layers, mainly composed of oxide of lead, which process consists in the admixture
with the oxide of lead of a soluble salt, which when brought by solution into
chemical contact with the oxide of lead will become decomposed and form with the
oxide of lead an insoluble salt of this metal and thus cause the material to "set"
and acquiro the required dense and coherent condition.
2. In the process of producing dense and coherent plates, or concreted masses or
layers of oxide of lead, the combination with a portion of the lead entering into
the composition of such plates, masses, or layers, of the acid radical of an ammonia
salt, the salt being such that its radical will form with lead an insoluble, or nearly
insoluble, salt of that metal, the object of such combination being to cause the
material of which the plate, mass, or layer is formed to "set" so that it will not
disintegrate when subsequently immersed in water.

page_text: "
3. The herein described process of peroxidizing plates, or masses, of oxide of lead
which has been caused to "set as herein described, by submitting them to the
oxidizing action of chlorine in the presence of water, substantially as specified.
4. The herein described process of peroxidizing plates or masses of oxide of 'lead
by submitting them to the oxidizing action of a hot aqueous solution of sodic or
magnesic hypochlorite, substantially as specified.