Improvements in Secondary Batteries.
Year: 1895

page_text: Date of Application, 29th Oct., 1895-Accepted, 7th Dec., 1895
Improvements in Secondary Batteries.
I, JOHN JOSEPH ROONEY of. No. 59 St. John's Place, Brooklyn, County of
Kings, State of New York, United States of America, Electrical Engineer, 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 battery as herein described and claimed consists preferably of a series of
plates. But, as I construct is, each plate instead of being either positive or
negative may be composite, in that it may contain both positive and negative
parts separated by insulating material. The best insulating material known to
me for this use is compressed paper like press-board, also called binders board.
This has the advantage that it is hard, light and porous as well as insulating. The
paper sheet is perforated with holes, preferably in vertical rows, which, after the
sheet is cut to the required dimensions, are filled with absoprtive material. This
perforated paper sheet forms the grid. The absorptive material filling the holes or
perforations forms pellets. The pellets in alternate rows may be connected
respectively to the positive and negative terminals so that adjacent rows of pellets
when charged will be of contrary polarity. This is the preferable arrangement.
But all pellets in one grid may be connected together to form a single positive or
negative element. A single plate immersed in a suitable liquid will form either
a complete battery or a positive or negative element, according to 'the arrange-
ment adopted for connecting up the pellets.
In the accompanying sheet of drawings,
Figure 1 is a side view of one form of my composite plate.
Fig. 2 is an edge view partly in vertical section.
Fig. 3 is a top view thereof.
Fig. 4 shows edge views of the insulating compressed paper illustrating the
original thickness and the thickness to which the paper swells when treated with
the sodium caustic solution, as hereafter described.
Fig. 5 is a side view of a modified 'form of plate, the celluloid covering 'being
partly broken away at the left.
Fig. 6 is an edge view, partly in vertical section of the plate shown in Fig. 5.
The hardness and density of the paper is of course due to the compression to
which it has been subjected in the preparation, and the sizing which consists of
resinous or other gummy matter generally speaking is necessary to hold the paper
together. Without this sizing it would be difficult to perforate the paper with
dies or punches or in any other convenient manner. After being perforated the
paper is freed from resinous and other gummy matter to leave as far as possible
only the vegetable fibre, which is the basis of the paper. One way of doing this
is by immersing it in a solution of sodium caustic for from 12 to 20 hours. This
treatment does not destroy the firmness of the paper. Either immediately or after
the paper has dried, it is immersed in dilute hydrochloric acid. The acid and the
sodium caustic left in the tissues by the preceding operation react upon each other,
and when this reaction has ceased the paper is immersed in water to wash it and
dissolve out any sodium chloride present therein. If desired, these three operations
of treating with sodium caustic, with hydrochloric acid, and with water, can be
conducted in one tank by withdrawing one liquid aud filling with the next as
required.

page_text: The paper after treatment is soft and pliable but firm, and is in its original
shape, but very much thicker, the deepening of the perforations being three or four
times (see Fig. 4) without any distortion of them. A grid p capable of receiving
a large amount of absorptive material of very light weight is thus obtained. It
has the additional advantage of being porous and exposing the absorptive material
on all sides to the electrolyte.
Either before or after thus distending the paper by removing its sizing, and
before or after perforating it, but preferably after both operations, the faces of
the paper may be coated with vulcanized rubber, or gutta-percha which covers
both faces and the outer edges, the faces of the interior walls of the perforations
being left uncoated. This can be accomplished by coating those parts of the grid
to be protected with a solution of rubber in spirits of turpentine or petroleum and
dusting powdered sulphur over them, or the powdered sulphur can be incorporated
with the rubber solution in proportion, by weight, of about one part sulphur to
twelve parts of rubber and this mixture be applied to the grid. The grids are
then placed in an oven and subjected for several hours to a temperature of about
one hundred and fifty degrees Centigrade until the vulcanizing process is completed.
The coating or envelope may be made of any depth desired by repeating the
operation one or more times after drying the coating last laid on. This vulcanizing
may be omitted. If oxides of lead are employed as the absorptive material, they
may be applied either in a powdered state or in a liquid state. If they are to be
applied as powder, the grid is first saturated with dilute, sulphuric acid or a solution
of sulphate of magnesia, and then laid upon a flat board. Each row of perforations
is then filled with the proper powdered oxides, and the whole compressed by
suitable means, thereby squeezing the liquid from the paper. The liquid is
immediately taken up by the absorptive material, enabling it to set and become
hard. If the oxides are applied in a liquid form it is best to have the paper damp.
The oxides are then brought to a paint-like consistency by mixing with a suitable
solution and poured into the perforations. The superfluous solution is quickly
absorbed by the paper leaving the absorptive material in a condition to dry and
set rapidly. In both cases, on drying, the paper shrinks and leaves the pellets of
absorptive material sticking above its surface, or in other words in relief, but the
paper swells again on being placed in the battery fluid. This absorptive material
is also called active material or material to become active.
In Figures 12 and 3, conducting strips s lie across the perforations and make
contact with the pellets of absorptive material, and also keep them from falling
out. The strips are folded over the upper edge of the grid and are provided with
clamping or fold-over lips at their ends, as is shown at the bottom of Fig. 1.
Thus each is wrapped around the grid along a vertical, row of perforatious. The
strips are perforated to allow the escape of gas, and the exposure of part of the
faces of the pellets to the electrolyte. Some or all of the strips may be provided
with separating shoulders m or other prominences, which project in front of the
faces of the strips to keep adjacent plates apart in the cell. The negative strips
are connected to the negative terminal bars c of the cell and the intermediate
positive strips to the positive bars . This I describe in the claims by the phrase
"alternated positive and negative conductor.." Thus all the positive conducting
strips are connected together, and all the negative conducting strips are connected
together, but the positive strips and negative strips are insulated from each
other by the grid of paper. It may, therefore, be stated that there are positive
and negative sets of conductors insulated from each other, the conductors being in
contact with the absorptive material.
In Fig. 1 extensions which form foot-rests are provided by suitably prolonging
preferably the negative rows of perforations. When the conductors, are attached
as shown, alternate conductors only rest upon the bottom, and as these are of the
same polarity, accumulations at the bottom of the vessel cannot cause short-
circuiting.
In Figs. 5 and 6 are shown conducting strips s', which are pushed down through

page_text: '
the grid along the middle of each row of perforations, while the grid is soft. Each
alternate strip is connected to terminal bar cor b. As here shown the conducting
strips do not enclose and hold in place the pellets of absorptive material. For this
purpose, perforated celluloid covers e are fastened to the grid..
It will be seen that in any one of the forms shown herein, the current will pass
longitudinally through the walls, separating the rows of absorptive material and
also outside of the grid in the mass of the liquid which fills the vessel. Instead of
immersing only plate in the vessel two or more may be so used, and all their
negative and positive poles respectively connected. If the plates are made all
alike they may be packed quite closely without danger of short-circuiting the cell,
since pellets of absorptive material or conducting strips of like polarity, will lie
opposite each other. The current will then pass not only between different pellets
of the same plate but through the liquid between positive and negative pellets of
different plates. But to permit circulation of the liquid, the plates should be held
somewhat apart, as -by the shoulders m on the strips, or corrugations on the
celluloid covers e, or in any suitable manner.
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. A secondary-battery plate consisting of a grid of perforated press-board
paper with the sizing removed, absorptive material filling the perforations, and
one or more conductors making contact with the absorptive material, substantially
as described.
2. A secondary-battery plate consisting of a grid of perforated press-board
paper with the sizing removed, absorptive material filling the perforations, and one
or more lead conductors making contact with the absorptive material, substantially
as described.
3. A composite secondary-battery plate made up of a grid of insulating
material, parallel rows of perforations therein, absorptive material occupying the
perforations, and alternated positive and negative conductors, each conductor
being in contact with the material in one row of perforations, substantially as
described.
4. A composite secondary-battery plate made up of a grid of porous paper,
parallel rows of perforations therein, absorptive material occupying the perfora-
tions, and alternated positive and negative conductors, each conductor being in
contact with the material in one row of perforations, substantially as described.
5. A secondary battery consisting of a suitable liquid in which is immersed one
or more composite secondary-battery plates each made up of a grid of insulating
material, parallel rows of perforations therein, absorptive material occupying the
perforations, and alternated positive and negative conductors, each conductor
being in contact with the material in one row of perforations, substantially as
described.
6. A secondary battery consisting of a suitable liquid in which is immersed
one or more composite secondary-battery plates each made up of a porous paper
grid, parallel rows of perforations therein, absorptive material occupying the
perforations, and alternated positive and negative conductors, each conductor
being in contact with the material in one row of perforations, substantially as
described.
7. A composite secondary-battery plate consisting of a grid of non-conducting
material vertical rows of perforations therein, the grid having extensions in the
line of alternate rows to form foot-rests, absorptive material filling the said
perforations, and alternated positive and negative conductors each in contact with
the absorptive material in one row of perforations, substantially as described.
8. A secondary battery which contains composite plates each made up of a grid
of non-conducting material, rows of perforations therein, absorptive material filling
the perforations, alternated positive and negative conductors each in contact with

page_text: the absorptive material in one row of perforations, the plates being packed
with conductors of like polarity on adjacent plates in contact, substantially as
described.
9. The method of preparing secondary-battery plates which consists in per-
forating a sheet of compressed paper and then reducing it to vegetable fibre by
removing its sizing and filling the perforations with absorptive material and
attaching conductors, substantially as described.
Dated the 15th Aar of October'1895
Signed in the presence of :-
THOMAS EWING, Jr.
SAMUEL WEREL BALCH.
JOHN JOSEPH ROONEY.