IMPROVEMENTS IN SECONDARY BATTERIES
Year: 1881

page_text: LETTERS PATENT to Desmond Gerald FitzGerald, of Brixton, in the County
of Surrey, and Charles Henry Walker Biggs and William Worby Beaumont,
both of the Strand, in the County of Middlesex, for an Invention of
PROVISIONAL SPECIFICATION left by the said Desmond Gerald FitzGerald,
Charles Henry Walker Biggs, and William Worby Beaumont at the Office of
the Commissioners of Patents on the 6th December 1881.
DESMOND GERALD FITZGERALD, of Brixton, in the County of Surrey, and
CHARLES HENRY WALKER BIGGS and WILLIAM WORBY BEAUMONT, both of the
Strand, in the County of Middlesex. “IMPROVEMENTS IN SECONDARY BATTERIES."
This Invention relates to the production of the plates or electrodes employed in
secondary batteries. It is necessary that these plates should expose large surface
to contact with the electrolyte, as for instance by being made porous or by multiple
folding.
One part of our Invention consists in making these plates by drawing sheets of
lead between two flat surfaces of wood or metal, one of which would have a
reciprocating motion of small range, and be provided with a number of fixed points,
such as pin or needle points, disposed in such a manner as to finely perforate the
sheet of lead which would be drawn at the necessary speed between the two
surfaces, so that the perforations should be closely contiguous. The points or
punches may be disposed so as to occupy intersecting points made by lines drawn
parallel to each other, and traversed by other parallel lines at a certain angle
thereto.
After perforation these plates are oxidised or chemically treated, so as to prevent
metallic union when being mechanically manipulated, as herein further set forth.
With this in view we prefer to immerse the perforated plates in dilute sulphuric
acid contained in a vessel from which air may be withdrawn, the object of this
being to fill the perforations with a fluid capable of acting superficially upon the
metal, so as to produce for instance a coating of lead sulphate within the
Derforations._

page_text: The material so treated may be at once employed to form electrodes, or the
sheets may be folded by simple or return folds, or corrugated and then pressed; or
they may be cut into strips and doubled into narrow flat strips and pressed or
rolled together, and may be at either or all these stages reperforated and treated,
as before described.
Another method of perforating those sheets of lead is to place together a quantity
of points, such as needles, so that they will be held with all their sharp or
perforating ends in one direction, like type in a printer's form, and either passing
the sheet over this form, as in a printing machine or in a press, or by giving the
form a reciprocating motion, or by fixing the form and drawing the sheet lead over
it and between a reciprocating platten. Another way of obtaining plates having
large surface, which we propose, is to place a quantity of lead granules or fragments
into moulds subjected to a temperature equal to or near the melting point of lead,
so that the granules or fragments may adhere by metallic union, but leavo
interstitial spaces. The plates or blocks so produced may be treated as before
described, so as to prevent metallic union between the interstitial surfaces, and.theu
be rolled out into thin plates, and if necessary perforated and re-rolled, as beforo
described.
We propose also to make these plates by the electro-chemical action of zinc on a
solution of the acetate of lead, by which crystals of that metal are obtained in an
arborescent form, and commonly known as Saturn's Tree, one way of producing
the porous plates being to insert black leaded lace in an electrolytic bath to receive
the coating of lead crystals.
Another method by which we propose to make these plates is to employ lead
wires, fibres, or fine threads, so as to form a flat mat, and then melt the ends of the
threads, which would be at the edges of the plates, together so as to form a
connected whole.
The mat so formed may be treated as previously described, so as to extend the
surface and prevent metallic union.
Another method by which we propose to make these plates is to weave a kind
of close gauze fabric of fine lead wire, made for instance by drawing or squirting;
one sheet so mado and treated as before described to prevent metallic union in the
interstitial spaces when subsequently rolled and reperforated, if necessary, may be
used as an electrode; or a number of sheets of this fabric may be placed together
and heavily pressed, and then connected by melting the edges together by soldering
iron, or by dipping them into molten lead. Plates so formed may then be treated,
re-rolled, and perforated, as before described.
Other methods may be employed for producing porous plates from fused lead,
and one method by which we propose to make these sheets is to cast plates in
moulds, the bottoms of which are filled with needle points, and we may also while
the plate is still plastic force into it a number of needle points fixed in a platten of
wood or metal. The plates may then be treated chemically, and by rolling, and if
necessary by reperforating, as previously described.
In this Specification lead only has been mentioned, but we do not propose to
confine ourselves to this metal alone.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Desmond Gerald FitzGerald, Charles Henry Walker Biggs, and
William Worby Beaumont in the Great Seal Patent Office on the 6th June
1882.
DESMOND GERALD FITZGERALD, of Brixton, in the County of Surrey, and
CHARLES HENRY WALKER BIGGS and WILLIAM WORBY BEAUMONT, both of the
Strand, in the County of Middlesex. "IMPROVEMENTS IN SECONDARY BATTERIES."
This Invention relates to the production of the plates or electrodes employed in
secondary batteries. It is necessary that these plates should expose large surface
to contact with the electrolyte, as for instance by being made porous or by multiple
folding.
One part of our Invention consists in making these plates by drawing sheets of
lead between two flat surfaces of wood or metal, one of which has a reciprocating
notion of small range, and is provided with a number of fixed points, such as pin
or needle points, disposed in such a manner as to finely perforate or puncture the
sheet of lead, which is drawn at the necessary speed between the two surfaces, so
that the perforations or punctures may be closely contiguous. The points may be
disposed so as to occupy intersecting points made by lines drawn parallel to each
other, and traversed by other parallel lines at a certain angle thereto.
After perforation or puncturing the plates are oxidised or chemically treated, so
as to prevent metallic union when being mechanically manipulated, as herein
further set forth. With this in view we prefer to immerse the perforated plates in
dilute sulphuric acid contained in a vessel from which air may be withdrawn, the
object of this being to fill the minute holes or punctures with a fluid such as dilute
sulphuric acid capable of acting superficially upon the metal, so as to produce for
instance a coating of lead sulphate within the perforations.
The lead sheet or plate so treated may be at once employed to form electrodes,
or the sheets may be folded by simple or return folds and then pressed, and may
be at either or all stages reperforated or repunctured, and treated as before described.
By this system of perforating and reperforating or puncturing at each operation,
treating the perforations or punctures as before described, we obtain a plate having.
great porosity.
In carrying our Invention into effect we find that it is of importance that the
aforesaid flat surface, which has a reciprocating motion of small range, and is
provided with a number of needle points for finely perforating or puncturing the
sheet of lead, should be of small area as compared with the area of the sheet of
lead. We therefore puncture the sheets or platos of lead by means of a number of
needle points placed in a holder having a reciprocating motion somewhat like the
needle holder of a sewing machine, the sheets being gradually fed under the needle
points by adjustable well known mechanical means, such for instance as those
employed in sewing machines, so that the distance between the punctures may be
controlled to great minuteness, and so as to make them so close together that there
is no assignable distance between them. The punctures may thus be made so fine
and so close together as to give the lead plate the character of true porosity.
In this way we have made porous plates, the needle holder in some cases
containing 75 needles in a circular tubular holder of about inch in diameter, and
the rate of feed of the plate being in some cases only about one hundred of an inch
for each stroke of the needle holder.
A machine and the needle or needle point holders for puncturing the plates in
the manner herein described may be made as shewn in the Drawings hereunto
attached, and which we will now describe.

page_text: In these Drawings Figure 1 is a side elevation of the machine, and Figure 2 an
end elevation; Figures 3, 4, and 5 are side view, sectional end view, and plan
section of one form of needle holder; and Figures 6 and 7 are vertical section and
side elevation of another form of holder.
In Figure 1, a is the needle point holder fixed by the set screw b into the boss c
in the end of the spring arm d. This arm has a reciprocating movement imparted
to it by the crank e and rod f, attached by a slightly flexible piece at g, and driven
by ordinary means, such as a strap running on the pulley h. The lead plate i to
be perforated or punctured rests upon the plate k, to which it is fixed by the
clamping screw L. The plate k has a radius arm k¹ attached to it, by which it is
connected to the sliding feed piece m in the boss n, and the end of the sliding
piece m being a screw m', which may move the piece k, k¹, by means of the hand
nut o, thus effecting the feed of the plate i under the needle points in one direction.
The plate & rests upon a sliding piece p, on the underside of which a rack is formed
at p, into which rack p¹ a pinion q gears. This pinion receives motion through
the medium of the ratchet wheel 7, ratchet 8, lever t, and rod u, a reciprocating
motion being given to the rod u, and thereby to the ratchet & by the crank v. Tho
levert may have a slot or holes, as shown, so as to adjust the amount of movement
given to the ratchet wheel r, and thereby to the pinion q and rack at p'.
The feed of the lead plate or sheet to be punctured is thus effected in the
opposite direction to that effected by the screw m² and the slide piece k, k'. The
feed movement effected by the ratchets and pinion q, and other details connected
therewith, by which the slide is moved in a direction transverse to that of the
machine, causes the plate with the lead plate or sheet to be carried also across
the machine, but the connection of the plate to the radius k¹ causes the plate
and the lead plate i to move in the arc of a circle, so that the lines of punctures
are curved. We do not necessarily require curved lines of punctures, but this
arrangement of transverse feed is convenient, though a straight line feed may, if
preferred, be given to the plate k by the well known mechanical means, which
however would not be so simple for the feed in the direction of the length of the
machine. The arm w is a spring finger arm, similar to a presser foot in a sewing
machine, to keep the lead plate i from rising when the upward stroke of the
needle holder is made, and it may nearly touch the lead plate, or may press upon
it with a pressure adjustable by the hand screw w'.
The end of this arin has a hole w³ to permit the needle points to reach the lead
plate, this hole being of the necessary form to suit the arrangement of the needle
points, whether held in a holder, as shown at Figures 6 and 7, which is the form
also shown at a, Figure 1, or whether of the form shown at Figures 3, 4, and 5.
The latter form of holder would usually be set, so that the line of the needle
points would be at an angle with the direction of length of the machine, so as to
make the punctures at points of intersection of parallel and angularly transverse
lines, as above described. This machine and these holders are only shown as some
of the forms which may be used to effect the puncturing or perforating. The
puncturing may be done on both sides of the lead plate.
Figure 8 is a side view, and Figure 9 an end view of an electrode punctured in
certain parts of the surface, leaving ribs for the sake of strength, but they may be
punctured all over.
Another method by which we obtain plates having large surface consists in
placing a quantity of lead granules or fragments into moulds or dies subjected to a
temperature equal to or near the meeting point of lead, so that the granules or
fragments may adhere by metallic union, but leave interstitial spaces, pressure
being applied to the mass while in the heated condition. In order more effectually
to preserve these interstitial spaces, especially when a considerable pressure, such
as 100 to 200 pounds on the square inch, is used, we may mingle with the lead
granules or fragments such other materials as will not only form permanent
components of the electrodes, but such as will obviate the necessity for pro-
ducing these materials on or in the electrodes by electrolysis by the process known

page_text: as "forming." These materials may be had in the form of oxide or sulphate.
And having made this mixture, we place it in moulds or dies subjected to a
temperature equal to or near the melting point of lead, and we, by preference,
simultaneously subject the heated mass to compression, so that the granules may
adhere by metallic union, the interstitial spaces being partly or wholly filled with
the oxide of lead or sulphate of lead. The plate or blocks so far produced may be
treated as before described to prevent further metallic union, or without this
treatment may, with the mould, be placed in a roller press or hydraulic press, so as
to complete the union of the metallic lead sufficiently to make the mass firmly
coherent, and may thus be made into thin plates, and if necessary perforated and
rerolled, as before described.
•
Another way by which we produce porous plates consists in inserting blackleaded
lace (net) in an electrolytic bath to receive a coating or deposit of lead. Or the
net instead of being coated with black lead, may be coated with a thin conducting
layer of a metallic sulphide or of a metal, by immersing for instance the net fabric
in a salt of copper or silver, and subsequently exposing the fabric to the action of
sulphide of hydrogen or of ammonic sulphide; or again by immersing the fabric in
a solution of salt of silver, platinum, or gold, and subsequently exposing the fabric
to the action of hydrogen gas or other suitable reducing agent at a sufficiently
elevated temperature, but one considerably below that which would effect tho
charring of the fabric. The fabric so treated is subsequently placed in an electro-
lytic bath to receive by electro deposition a coating of lead. A number of the
sheets of lead coated fabric thus obtained are preferably superposed and subjected
to the operation of rolling or pressing, after which they may be folded and rerolled
or repressed. At each of these stages the surfaces may be oxidised as before
described, but in this process of manufacture the chemical separation of the
surfaces is not essential.
Another method by which we propose to make these plates is to weave a kind of
close fabric of lead wire, made for instance by drawing or squirting. One sheet so
made and treated as before described to prevent metallic union in the interstitial
spaces may, when subsequently folded and rolled or pressed, and if necessary
reperforated and be placed together or folded together and heavily pressed, and
then connected by melting the edges together by soldering or by dipping them
into molten lead. Plates so formed may then be treated, rerolled, and perforated,
as herein before described, and at a number of spots, say, two or three inches apart,
the material of these sheets so made may be rivetted with lead rivets, or melted
together by a heated tool or bolt, like a flat ended copper soldering tool, or by
other equivalent suitable means, so as to give strength to the fabric.
And having thus described and ascertained the nature of this Invention, and the
manner in which the same is or may be carried into effect, we declare that we
claim,―
Firstly. The construction or manufacture of porous electrodes for secondary
batteries by minutely puncturing one or both surfaces of sheets or plates of lead,
substantially as hereinbefore described.
Secondly. The construction or manufacture of porous electrodes for secondary
batteries by the combined processes of minutely puncturing both surfaces of lead
sheets or plates, then treating the plates by immersion in dilute sulphuric acid in a
vessel from which air may be withdrawn so as to produce a deposit of lead
sulphate thereon, then rolling the plates so as to extend their surface by reduction
of thickness, and finally repuncturing or reperforating the plates, substantially as
herein before described.
Thirdly. The construction of porous electrodes for secondary batteries by the
electro deposition of lead on a fine net fabric, so as to obtain a lead fabric, which is
preferably folded in as many folds as may be desirable to make up any required
thickness and then pressed, substantially as herein before described.
Fourthly. The construction of porous electrodes by the application of heat and.

page_text: pressure to lead granules with or without oxide, or sulphate of lead in suitable
moulds, substantially as described.
Fifthly. The construction of porous electrodes for secondary batteries from
fabrics of woven lead wire, chemically treated, folded, and pressed, substantially as
herein described.
In witness whereof, we, the said William Worby Beaumont and Charles
Henry Walker Biggs, for ourselves and on behalf of the said Desmond
Gerald FitzGerald, have hereunto set our hands and seals, this Fifth day of
June, in the year of our Lord One thousand eight hundred and eighty two.