Year: 1898

page_text: I, WALTER AMBROSE CROWDUS, of 1303, Marquette Buildings, Chicago, Illinois,
United States of America, Inventor, do hereby declare the nature of this invention
to be as follows:-
My invention relates to secondary batteries in which the elements are formed
by applying lead salts to mechanically conducting supports. The said invention
is designed both to increase the efficiency of conversion between charge and dis-
charge and to increase the weight of the cell without impairing its commercial
value.
An important feature of the invention consists in forming negative or spongy
lead elements by immersing plates coated with lead oxide in a solution containing
sulphuric acid and a sulphate of an easily oxidizable metal such as zinc, and pass-
ing a current to the plates therein.
A further important feature consists in constructing a supporting plate of thin
sheet metal preferably of aluminum perforated or slotted in such a manner that
the bars or portions left between the perforations are bent towards opposite sides of
the plate so as to form open channels extending longitudinally and transversely
through the plate.
In a secondary battery constructed according to my invention, the plates are so
arranged that their active and inactive portions are arranged in alternating lines,
and the said plates are kept apart and prevented from buckling by corrugated and
perforated non-conducting separators, formed of india-rubber for example. The
angles, corrugations or folds of these separators touch the plates only in line with
the inactive portions of the plates.
In order to ensure uniform electrolytic action over the whole of the plates, I
connect together the similar elements of the cell at two or more points below the
level of the electrolyte.
The positive plates may be made of thin, rolled sheet lead, and provided with a
series of rectangular or elongated perforations. The plate is provided with legs
or terminals at the top and bottom portions thereof so that plates of the same
polarity may be electrically connected together at the top and bottom, and thus
ensure uniform electrolytic action. The ribs or strips left between the elongated
perforations are bent alternately to opposite sides of the plate, so as to form longi-
tudinal recesses substantially the entire length of the plate, with openings on each
side thereof, to hold the active material. The latter consists preferably of specially
prepared hard but porous paste of red lead. This arrangement permits of a very
light plate, the presenting of a large active surface and a greater amount of active
material than any other form of construction.
For the negative elements, I use plates similar to those used for the positive
elements, with the exception that I use the metal aluminium instead of lead.
By placing the porous red lead paste in the plate, it is locked therein from side
o side and throughout its entire length, as in a cage, and prevented from falling

page_text: out, while at the same time the surface of the active material represents a larger
percentage of the surface of the plate than ever accomplished before, thereby greatly
increasing the surface of the active material and the output of the plate; the weight
of the cell being also largely decreased per unit of work. In practice, the weight
of my positive lead support, when compared to the active material on it, is as 1: 2,
a result never practically obtained before.
The elements are connected together by bending the terminals or lugs substan-
tially at right angles to the plate, and connecting the plates of similar polarity to
each other by means of rivets, for the negative plate, and also by autogenous solder-
ing in the positive plate. The sets of plates are then immersed in the special
forming bath, consisting of an aqueous solution of about one-third saturation of
sulphate of zine with fifteen per cent., by volume of sulphuric acid. In this
solution I place the plates to be formed, suitably arranged between sheet lead
anodes as dummies, and pass a current of about one ampere for every three square
inches of the plates to be formed. On passing the current, to the plates, the
sulphate of zinc is decomposed, depositing pure zinc upon the negative plates,
which is re-dissolved from the plate as fast as it is deposited, by the sulphuric acid
of the solution, thus producing a quantity of hydrogen. By the reducing action
of the hydrogen the oxide of lead is rapidly converted into spongy lead. By this
process the time of formation is reduced to about two hours-about one-fifteenth
of the time required in the processes in actual use at present. By this method of
forming the element, the dissolved zinc is returned to the solution, so that the same
solution can be used over and over again for an indefinite period. I have found
in experimental tests that the positive plates, when first formed into negatives or
spongy lead by my process, and then into positives, will give almost their full
output on the first discharge, while the old methods require several charges and
discharges before the positive plates are fully formed. I, therefore, also quicken
and cheapen the formation of my positive plates by the use of my quick negative
formation.
After formation the elements are placed in the battery, and, in order to strengthen
and insulate the plates and prevent warping or buckling of the same, the corrugated
insulating perforated separators are inserted between the opposing pairs of plates
and touch such plates at their inactive portions. By this arrangement no active
material is covered by contact with the insulating rubber separator, and the internal
resistance of the cell is thereby greatly reduced.
I then secure to the terminals of the positive lead-platos a terminal lug of lead,
and a similarly shaped lug of aluminum to the terminals of the negative plates,
to which the circuit wires are intended to be attached.
It is well known that each time a cell is recharged, the negative element decreases
in capacity, and that after a time a reversal of the polarity of the positive and
negative elements is necessary to bring the cell back to its original capacity. I
avoid this and increase the efficiency of the conversion between charge and dis-
charge by adding to the usual sulphuric acid electrolyte, a very small proportion
of sulphate of zinc, just sufficient to hasten, as described in my forming-bath, the
restoring of the negative element, so that its full capacity is restored as quickly as
that of the positive element.
In the construction of storage batteries, all builders connect the elements
together by a terminal at the top ends, and at one point only. I have discovered
that in elements connected in this manner, the passage of the current to and from
the positive and negative plates is greatest nearer to the terminal lugs, and that
it gradually decreases to the more remote points. This action brings about uneven
electrolysis upon the plates, to the extent that the portion of the plate nearest the
terminal is exhausted or is restored quicker than the more remote portions, in
consequence of which the capacity of the battery is decreased below the capacity
of the active material. It also produces partial polarization and unequal expansion
and consequent distortion or warping of the plates. By my invention I remove
tbese objections and obtain a much more uniform electrolysis on every portion of

page_text: the plate by connecting the plates of similar polarity at two or more points below
the level of the electrolyte. It will be understood, however, that instead of using
two terminals, I may use but one, and have that one extending nearly the entire
length of the plate, or three terminals, or even more may be used.
The plates of opposite polarity are placed in juxta-position with each other, so
that the connected edges are on opposite sides of the pile. In the use of secondary
batteries, the terminals above or outside of the electrolyte are destroyed by the
sulphating of the lead, due to the combined corrosive action of the air and acid,
and to overcome this, large heavy lugs are resorted to. I avoid this objection by
completely immersing the terminals of the elements at the point where they con-
nect, so that I can successfully use thin plates in my elements, where hitherto
destructive sulphating has made it impossible.
While I have described my invention with more or less minuteness as regards
details, and as being embodied in certain precise forms, I do not desire to be strictly
limited thereto, as the same are only intended as examples.
Dated this 20th day of January 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, WALTER AMBROSE CROWDUS, of 1303, Marquette Building, Chicago, Illinois.
United States of America, Inventor, 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 relates to secondary batteries in which the elements are formed
by mechanically applying lead salts in the form of paste to metal plates or sup-
ports therefor.
Heretofore, in order to prevent the warping or buckling of the said plates or
supports, they have been hardened with alloys, or an increased quantity of lead
has been used in their construction, so that they presented a large exposed surface,
as compared with that of the active material. Attempts have also been made to
use aluminium as a support for the lead paste or active material, but such attempt;
have failed, for the reason that the paste does not adhere readily to the aluminium.
Now my invention is intended to obviate these objections, and to provide a
simple, economical and efficient secondary battery, which shall be very light in
weight and possess a large electrical capacity.
A further object of my invention is to expedite and render more efficient the
process of formation" of the battery elements.
66
According to my invention I construct the plate or support of thin or mechanically
weak metal such as rolled sheet lead or aluminium, perforated or slotted and bent
in such a manner that the bars or portions of metal between the perforations pro-
ject beyond the plane surfaces of the plate and thereby leave open channels that
extend longitudinally and transversely through the plate as hereinafter more fully
explained.
In order to separate and maintain the said plates in position I employ corrugated
and perforated non-conducting separators composed for example, of india-rubber.
The angles or corners of the corrugations of these separators are abrupt and only

page_text: touch the plates at their inactive portions. The said separators also assist in pre-
venting buckling of the said plates.
I form the negative elements of the battery by immersing conducting plates or
supports coated with lead oxide, in a solution containing sulphuric acid and a
sulphate of an easily oxidizable metal such as zinc, and passing an electric current
through the solution and to the plates in the usual way. I prefer to obtain the
positive elements by first forming them into negative elements in a similar manner
to that above described and then forming them into positive elements by reversing
the direction of the flow of current to the plates.
In order that my invention may be clearly understood and readily carried into
effect, I will describe the same more fully with reference to the accompanying
drawings, in which :-
Figure 1 is a vertical sectional elevation of a secondary battery, constructed in
accordance with my improvements and taken on line 1 of Figure 4.
Figure 2 is a side elevation of a plate or support before the active material has
been applied thereto and before the plate terminals have been bent to be secured to
the adjacent plates.
Figure 3 is an enlarged, transverse, sectional elevation of a portion of the
plate with the active material applied to a portion thereof, taken on line 3 of
Figure 1.
Figure 4 is a sectional view, taken through the battery on line 4 of Figure 1.
Figure 5 is a side elevation of a portion of the upper part of the plates with the
multiple and terminal connections.
Figure 6 is a sectional view, taken on line 6 of Figure 5, showing the terminal
bar.
Figure 7 is a side elevation of one of the insulating separators before it has been
corrugated; and
Figure 8 is an end view of one of the insulating separators after it has been
formed in the desired shape.
In constructing a secondary battery in accordance with my invention, I make
a positive plate or support A, of thin, rolled sheet lead, and provide the same with
a series of rectangular or elongated perforations a The plate is provided with
terminals A and A2, at the top and bottom portion thereof, so that elements of the
same polarity may be electrically connected together, at the top and bottom, and
thus ensure uniform electrolytic action. The bars a, formed by and between the
elongated perforations are bent alternately to opposite sides of the plate, so as to
form longitudinal recesses or channels substantially the entire length of the plate,
and openings on each side thereof, to hold the active material B, which consists
preferably of a specially prepared, hard, but porous paste made from pure desilver-
ized powdered red lead mixed with dilute sulphuric acid. The plate is free to
expand under pressure from the salts, but has its expansion directed principally
in straight lines parallel with the face of the plate, that is, the plate may stretch
equally in all directions so that there is no tendency to buckle or be otherwise
damaged by the expansion of the lead salts of positive plates. A very light element
is thus produced, which at the same time presents a large active surface and a
greater amount of exposed active material than any other form of construction,
whereby the output of the element is greatly increased; the weight of the cell being
also largely decreased per unit of work. In practice, the weight of my positive
lead support, when compared to the active material on it, is as 1: 2 a result never
practically obtained before.
In order to make my improved negative element, I use a plate similar to the plate
above described in connection with the positive element and shown in Figures 1,
2 and 3 of the drawings, with the exception that I use the metal aluminium for
the supporting plate, instead of lead. I use the same paste for active material.
By placing the material in the plate, as shown in Figure 3 of the drawings, it is
held or locked therein as in a cage, and prevented from falling out.
The elements are connected together by bending the terminals, A¹ A², sub-

page_text: tantially at right angles to the plate, and connecting the plates of similar polarity
to each other by means of rivets, a³, for the negative plate, and also by autogenous
soldering in the positive plate.
The sets of plates are then filled with the aforesaid paste of oxide of lead and
mmersed in the special forming bath, consisting of an aqueous solution, of about one-
hird saturation, of sulphate of zinc or of other easily oxidisable metal, with fifteen per
cent., by volume, of sulphuric acid. The plates are arranged between sheet lead
anodes as dummies, and I pass an electric current of about one ampere for every
three square inches of the plates to be formed. On passing the current to the
plates, the sulphate of zinc is decomposed, depositing pure zinc upon the negative
pole plates. This deposited zine immediately reacts, chemically, with the sulphuric
acid present in the solution, thus liberating hydrogen on the surface of said plate.
This hydrogen, together with that produced by the electrolysis of the acidulated
water, rapidly reduces the oxide of lead to spongy lead. By this process there is
therefore an extra amount of hydrogen evolved at the surface of the negative pole
plate beyond that evolved directly by electrolysis, and the time of formation is
thereby reduced to about two hours-about one-fifteenth of the time required by
the processes heretofore in use. By this method of forming the negative element,
the dissolved zinc is returned to the solution, so that the same solution can be used
over and over again for an indefinite period; and I have found in experimental
tests that the positive elements, when first formed into negative or spongy elements
by my process, and then into positive elements, will give almost their full output
on the first discharge, while positive elements produced according to the old
methods require several charges and discharges before they are fully formed. I,
therefore, also expedite and cheapen the formation of the positive elements by the
use of my quick negative formation.
"
After formation the elements are placed in the battery, as shown in the
sectional view in Figure 4, and, in order to support and insulate them and prevent
warping or buckling of the same, I insert between the pairs of opposite elements
a corrugated insulating perforated separator, C, which touches such elements at
their inactive portions. By this arrangement, no active material is covered by
contact with the insulating rubber separator, and the internal resistance of the
cell is thereby greatly reduced. I then secure to the terminals of the positive lead
plates a T-shaped terminal lug, D, of lead, and a similar shaped lug, D', of
aluminium to the alumium terminals of the negative plates, to which the circuit
wires are intended to be attached.
It is well known in this art that each time a cell is recharged the negative
element decreases in capacity, and that after a time a reversal of the polarity of
the positive and negative elements is necessary to bring the cell back to its original
capacity, I avoid this and increase the efficiency of the conversion between charge
and discharge by adding to the usual sulphuric acid electrolyte--with which all
batteries are supplied a very small proportion of sulphate of zinc, just sufficient
to hasten, as described in my forming-bath, the restoring of the negative element,
so that its full capacity is restored as quickly as that of the positive element.
In the construction of storage batteries, it has heretofore been usual to connect,
the elements together by a terminal at the top end and at one point only. In such
cases however the escape of the current to and from the positive and negative
elements in the charge or discharge of the battery is greater nearer to the terminal
lugs, and gradually decreases toward the more remote points. This action causes
O uneven electrolysis upon the elements, to the extent that one portion thereof-that
nearest the terminal--is exhausted or restored quicker than the more remote
portions, in consequence of which the capacity of the battery is decreased below
the capacity of the active material. The said action also produces partial polariza-
tion and unequal expansion, and consequent distortion or warping of the plates.
5 In order to remove these objections and obtain a much more uniform electrolysis
on every portion of the element I connect the elements of similar polarity at two
or more points below the level of the electrolyte, which level is shown by the

page_text: dotted line X in Figure 1 of the drawings. Instead of using two terminals, I may
use one which extends nearly the entire length of the plate, or I may use three or
more terminals. I also prefer to arrange the plates of opposite polarity with
their terminals on opposite sides of the pile, as shown.
Further, in the use of batteries, the terminals of the elements above or outside
of the electrolyte are destroyed by the sulphating of the lead, due to the combined
corrosive action of the air and acid, and to overcome this recourse has been had
to the use of heavy lugs. I avoid this objection by completely immersing the
terminals of the elements at the point where they connect, so that I can success-
fully use thin plates in my elements, where hitherto destructive sulphating has
made it impossible.
While I have described my invention with more or less minuteness as regards
details, and as being embodied in certain precise forms, I do not desire to be
strictly limited thereto, as the same are only intended as examples.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is;-
-
1. The method of forming a secondary battery element by immersing a metal
plate or support coated with lead oxide in a solution containing a sulphate of an
easily oxidizable metal, such as zinc, and sulphuric acid, and passing an electric
current through such plate.
2. A secondary battery plate, composed of a thin sheet of metal which is so per-
forated and bent that open channels are formed longitudinally and transversely
through the plate, substantially as and for the purpose described.
3. The combination with the positive and negative elements arranged substan-
tially as set forth, of a non-conducting perforated and corrugated separator having
the apex of its angles in contact with the inactive portions of the battery elements
for the purpose specified.
4. A secondary battery having its parts constructed arranged and combined
substantially as described with reference to the accompanying drawings.
Dated this 17th day of October 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.