Improvements in Secondary or Storage Batteries.
Year: 1891

page_text: Date of Application, 9th June, 1891-Accepted, 25th July, 1891
COMPLETE SPECIFICATION,
Improvements in Secondary or Storage Batteries.
I, STANLEY CHARLES CUTHBERT CURRIE, a subject of the Queen of Great
Britain, but now residing at No. 820 Drencl Building 5th & Chestnut Streets in
the City of Philadelphia, in the County of Philadelphia and State of Pennsylvania,
Electrical Engineer, do hereby declare the nature of my invention for IMPROVE-
MENTS IN SECONDARY OR STORAGE BATTERIES, and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statements:-
My invention relates to the plates or elements of a so-called secondary or storage
battery.
Hitherto the methods generally employed for the manufacture of plates or
elements of a secondary or storage battery have either been the purely electrolytic
or Plantè method or the mechanical method of applying under pressure lead oxides
to a conducting frame or support.
My invention has relation to the former method but embracing novel and
important features and steps in connection with the same for the production of
battery plates or elements.
The principal object of my present invention is to provide a cheap, durable and
efficient battery plate or element of any suitable shape or form adapted for use as a
secondary or storage battery and a plate or element which will not disintegrate ro
possess the deleterious effects hitherto existing in the plates or clements of electric
batteries.
My invention consists of a battery plate or element produced substantially in the
manner hereinafter described and pointed out in the claims.
In order that my invention may be fully understood a brief description will now
be given of a general method of producing the same and in that connection will be
pointed out the particular characteristic features of the battery plate or element so
produced.
In the present invention the principal object is to convert or transform ordinary
lead cast or rolled partially into a porous or soft spongy metallic state or condition
by electrolysis for use as a battery element.
Heretofore the principal objections presented to the method of reducing a plate
of lead or similar material by electrolytic action to a spongy metallic state or
condition in a solution of dilute sulphuric acid has been the extreme length of time
required to render the lead spongy or porous and of sufficient thickness or bulk for
practical purposes. This method as is well known requires a number of reversals
of the electric current so that it is impossible to attain the required result without
a constant repetition of the treatment. The principal reason being that only the
surface of the lead is oxidized at first, but just as soon as this small amount is fully
oxidized the oxygen being unable to be further taken up by the lead escaped in
the form of gas. This of course is the case when simple lead constitutes the
elements and they are immersed in a bath composed of dilute sulphuric acid. I
have discovered by a series of experiments, that it is possible to penetrate into a
plate or block of ordinary lead by electrolytic action in such a manner as that but
one or two reversals of current are required and that the lead can be quickly and
effectually penetrated to the required depth; and moreover, that the salt of lead
into which such plate or block is converted in the first instance is brought to such
a state or condition as to be readily reducible again to lead in a soft spongy or
porous metallic condition and afterwards formed by the ordinary process or
treatment with but one or two reversals. The principle above defined forms the
basis upon which my present invention is founded and I adopt the line of action
ro 017

page_text: hereinafter prescribed for practically and efficiently carrying the same into effect
for the production of a battery plate or element.
For example, two plates or blocks of lead are immersed in a suitable liquid or
bath and in a solution in which the lead is insoluble. The blocks or plates of lead
being arranged therein as anodes, and, cathodes. An electric current is then passed
which causes in a short period of time the anode to be gradually but uniformly
transformed to the required depth forming thereby a layer or thick film of lead
salt as a part thereof and of such general character as experience has demonstrated
may be quickly transformed by a simple reversal of current into porous metallic
lead or to a spongy metallic state or condition, for use as an element of a battery,
when mounted in a suitable electrolyte, such as dilute sulphuric acid. The element
being formed therein in the ordinary manner. As the plate or element is thus
produced in a porous or spongy condition no constant reversals of current are
required. The solution to mount the plate or block of lead in for its conversion in
the first instance, is preferably composed of chloride of zinc (Zn. Cl₂). It has been
ascertained by practical experiment, that if a current is passed from a lead anode
to a lead cathode in a solution of zinc chloride, lead chloride is formed upon the
surface and which extends into the body thereof (without any escape of gas,) yet if
the plate so treated was not otherwise protected, this lead chloride would fall to the
bottom of the tank, thereby rendering the plate or block practically useless. To
obviate such difficulty presented or disadvantageous feature arising means have
been devised forming a part of the present invention in which the lead chloride so
formed is retained to the internal body of the plate or block without interfering in
any manner with the converting or transforming steps of the process for the pro-
duction of the battery clement. This step being permitted according to my
invention to continue.under due regulation until the required depth of lead chloride
is formed. As soon as the required depth of chloride surface has been obtained,
which can be readily ascertained from the quantity of current permitted to pass, it
is transferred and becomes the cathode element of the tank. As the solution of
the tank is chloride of zinc, when a current is caused to pass, there is deposited.
metallic zine on the cathode. This metallic zinc it has been found hastens the
reduction of the lead chloride of the cathode to a metallic state or condition and
remains, that is to say, the zinc in the solution and thus it may be used over
and over again. The retaining medium for the plate or block of lead during
its aforesaid treatment as well as during its use as a battery element preferably
consists of a casing or covering of woven or braided asbestos or analogous
material.
In the practice of the present invention it is preferred that the lead plates or
elements in the first instance should be simply a series of rods or wires. When the
plates are in the form of blocks or plates of lead as in the first instance mentioned,
the asbestos will be cut in lengths and suitably applied thereto and the lead in a
molten state poured into suitable molds and the lengths of asbestos subsequently
caused to surround or envelop the same; while in the latter case the asbestos will
be braided or otherwise caused to surround the lead wires or rods, and the rods or
wires then preferably formed into a series of loops with a single conductor therefor.
Each series of the rods or wires with the woven or braided asbestos around them
constituting a plate. The method or manner hereinbefore described of constructing
the plates applies more particularly to the peroxide plates, but the asbestos
covering is retained and effectually prevents disintegration of the peroxide plates
after continuous action in use as a storage battery.
Having fully described the nature of the invention and pointed out the particular
features thereof, I will now refer to the accompanying drawings illustrating, the
mode of treating such materials for the production of a battery plate or element
such as hereinbefore described and showing a complete battery for, use; and in
which
Figure 1, is a perspective view of a tank showing two plates embodying the
features of my invention arranged as anodes and cathodes therein,, immersed in a

page_text: suitable solution and this view illustrating a preferred mode of carrying my
invention into effect.
Fig. 2, is a vertical section through a tank showing a plate composed of a series
of depending blocks of lead or analogous material partly in elevation and partly in
section to more fully illustrate the mode and extent to which each block or rod of
the series constituting the plate is penetrated; and showing also the central core or
body of ordinary lead undisturbed by such action to become a part of the
conducting means of the plate in conjunction with the horizontal bar or rod burnt
or otherwise applied to the upper parts of the series of blocks constituting the
battery plate.
Fig. 3, is a similar view of a modified form of plate embodying the particular
features of my invention; and
Fig. 4, is a sectional view of a complete cell on different lines but at right angles
to the plates, the said view showing two systems of battery plates or elements
embodying the features of my invention mounted in said cell and in forms adapted
as such for use as a complete secondary or storage battery; and
Fig. 5, is a similar view showing modifications of the plates or elements.
Referring to the drawings a, is a tank constructed of any suitable material and
of any preferred form. b, is a suitable solution contained in said tank and
preferably composed of dilute chloride of zinc. c, are the series of blocks, rods or
wires of lead or analogous material enveloped or incased in a covering or case d,
preferably composed of woven or braided asbestos or analogous material. is a
conductor burnt or otherwise applied to the tops of the series of blocks, rods or
wires c, constituting the respective plates. f, Figs. 2 and 3, represents in section
the blocks or rods penetrated or transformed by the electrolytic action permitted to
take place in the tank a, and converted by such action into a chloride or salt state
or condition and then by a simple reversal reduced to a soft spongy or porous
metallic condition. g, represents the internal body or solid core maintained free
from such action and in its normal state or condition as metallic lead and in such
state or condition becomes a good conductor in the subsequent use of the plate as
an element of a secondary or storage battery.
The method of carrying my invention into effect, is as follows:-
The plate or anode designated in Fig. 1 by the letter ", mounted in the tank a,
after the passing of a current for a required time becomes coated on the surface of
the lead beneath the asbestos or analogous outer woven or braided covering or
casing with a layer of chloride of lead (PbCl₂) and to the required depth thereof.
It is then removed and replaces the plate or cathode designated by the letter f³, in
the tank a, which by this time has been reduced as far as the internal core or body
thereof to a porous or soft spongy metallic state or condition for use; and so on in
regular succession and in a similar manner plates to be treated are placed in the
tanka, immersed in the solution composed preferably of dilute chloride of zinc for
the aforesaid treatment. The solution being constantly recovered in the manner
hereinbefore fully described.
In Fig. 4, is illustrated a complete cell showing a system of positive plates f',
embodying the particular features of my present invention mounted in the cell in a
suitable solution with a system of negative plates f³ of any suitable form or shape
and condition.
In Fig. 5, is illustrated a complete cell showing two systems of plates and f³,
mounted therein, in dilute sulphuric acid. It will be observed that the woven or
braided asbestos or analogous fibrous material casing or covering d, of each of the
plates serves not only to support the spongy or porous metallic portion thereof, but
also constitutes a most efficient insulating means between the respective plates
constituting said two systems mounted in the cell.
In the practice of the present invention it has been demonstrated that not only
very cheap and exceedingly durable battery plates are produced by the method
hereinbefore described, but a most efficient, economical and lasting battery is
obtained and one in which disintegration of the elements does not take place in the

page_text: use thereof and many other deleterious effects are obviated that were incident to
batteries as hitherto employed for storing up electric energy.
Instead of employing chloride of zinc for the solution during the converting stage
of the method of producing the plates, chloride of iron may also be used with good
results.
Having now particularly described and ascertained the nature and objects of my
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. A. battery plate or element having a metal core or internal conducting body
with an integral spongy or porous metallic surface and inclosed in a casing or
covering of woven or braided fibrous material or materials, substantially as
described.
2. A. battery plate or element composed of rolled or cast lead spongy or porous
to the internal core or body thereof and inclosed within woven or braided fibrous
material, substantially as described.
3. A battery plate or element composed of lead porous or spongy to the internal
metallic core or body thereof and incased in woven or braided asbestos, substantially
as described.
4. A battery plate or element composed of a series of rods, bars or wires of cast
or rolled lead covered with woven or braided asbestos and the wires, bars or rods
constituting the plate porous or spongy to the internal core or body thereof,
substantially as described.
5. A battery plate or element composed of a series of blocks, bars or wires of
cast or rolled lead incased in woven or braided insulating material and the said
incased wires, bars or blocks to the integral metal core in a soft, spongy or porous
metallic state, substantially as described.
6. A battery plate or element composed of blocks rods or wires of cast or rolled
lead incased in woven or braided asbestos and the said blocks, rods or wires porous
or spongy to the integral core or conducting metallic body thereof, substantially as
described.
7. The combination, in a secondary or storage battery, of a cell, a suitable
electrolyte and two systems of plates or elements composed of blocks, bars or wires
incased in woven or braided asbestos or analogous fibrous material mounted in said
cell and the said wires, blocks or bars having a spongy or porous surface to the
internal and integral metallic core thereof and bars burnt or otherwise applied to
the upper parts of said plates, substantially as and for the purposes described.
Dated this 8th day of May A.D. 1891.
STANLEY CHARLES CUTHBERT CURRIE.
W. P. Thompson & Boult,
Agents for the Applicant.