Improvements in Secondary or Storage Batteries or Accumulators and in the Manufacture of the same.
Year: 1897

page_text: Date of Application, 29th June, 1897-Accepted, 31st July, 1897
COMPLETE SPECIFICATION.
Improvements in Secondary or Storage Batteries or Accumulators
and in the Manufacture of the same.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Loudon'
Gentleman do hereby declare the nature of this Invention (which has been com-
municated to me from abroad by James Phillip Clare, Insurance Solicitor and
George Elwyn Hatch, Electrician, both of Quincy, County of Norfolk, Stute of
Massachusetts, one of the United States of America, and John Henry Taylor, of
Chelsea, County of Suffolk, State of Massachusetts aforesaid Attorney at Law) and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
One object of this invention is to so construct, or form, a secondary battery
element as to combine the excellent electrical and chemical results due to the
forination of active material by the "Plauté" method with the cheapness and
increased capacity which follows the formation of the active material in accordance
with the methods of Faure and Brush.
A further object of this invention is to provide for the use of porous terra-coita
plates of large size for supporting the active material in contact with the electrode
without unduly increasing the bulk, weight, or cost of said porous terra-cotta
supporting plates, the plates of the battery being at the same time self-accommo-
dating to irregularities of expansion, or contraction of the active material, and to
such buckling of the electrode as may take place while risk of forming electrical
connections between adjoining elements of the battery is effectually prevented.
These objects are attained in the manner hereinafter set forth, reference being
had to the accompanyiny drawings, in which,-
Figure 1 is a vertical section of a secondary battery of four elements, constructed
in accordance with this invention;
Figure 2 is a sectional plan of the same taken on the line - Figure 1;
Figures 3 and 4 are face views on a smaller scale of the sectional porous plates
constituting part of each element;
Figures 5 and 6 are back views of said' plates; and
Figure 7 is a perspective view of a special form of conducting plate or electrode.
The method of autogenous formation of active material upon the conducting
plate, or element, of a secondary battery by the electrolytic decomposition of the
metal of the plate itself, as adopted by Planté, gives the best electrical and
chemical results but is regarded as commercially impracticable because of the
expenditure of time and current necessary for this method of formation.
Modern secondary batteries, therefore, are made in accordance with the plan of
Faure and Brush, which consists in mechanically applying mettallic oxide to the
conductor, or electrode, either in the form of a paste, paint, or cement, or in the
forin of a powder pressed upon, or into, the electrode, so as to be self-sustaining
thereon, or therein, this plan very materially cheapening the battery as well as
increasing its capacity.
It is well known however that secondary battery elements formed in accordance

page_text: with the method of Faure, or Brush, are wanting in physical agglomeration of the
mechanically applied active material with the metallic electrode, so that in dis-
charging, a layer of sulphate of lead is formed, between the metallic lead and the
active, material, which sulphate injuriously affects the electrical result.
This invention is designed to overcome the objections while retaining the
advantages of both of the methods of formation hereinbefore referred to.
This object is attained according to this invention by first autogenously forming
the active material upon the metallic electrode by electrolytic decomposition of
the surface of said electrode, then confining active material, or material to become
active, in contact with the active material, thus autogenously produced, and con-
tinuing the electrolytic action so as to unite the two.
The accompanying drawing shews a battery composed of elements, or cells,
especially devised for facilitating this method of manufacture, each cell, or element,
being composed of opposite plates 1, of porous earthenware, or other porous
material, not susceptible to electrolytic action, each of these plates being preferably
composed of sections for the purpose hereinafter set forth, and said sections, being
so arranged that the horizontal joints between the sections of one plate are 'out of
line with the horizontal joints of the sections of the opposite plate of the element,
or of the adjoining plate of the next element, so as to prevent the risk of short
circuiting which, if the said joints were in line, might follow the failure to remove
active material from the horizontal faces of the sections of the plate before setting
up the sections.
Each section of each side plate of the cell has its inner face provided with
recesses, pits, grooves, cells, or a like formation, the cellular formation being shown
for example in Figures 3 and 4 of the drawing, and the plates are grooved near the
edges so as to provide for the insertion in the bottom and side grooves of each
plate of a stri 3 of comparatively thick rubber or other elastic or semi-clastic
material not suscentible to electrolytic action and capable of forming a water-tight
joint with the strip of the opposite plate of the cell.
Instead of providing the opposite plates of each element with rubber strips
meeting edge to edge, a single strip may be adapted to the grooves in both plates if
desired.
The two plates of the cell in connection with the packing strip or strips 3 thus
form an element of the vessel type, that is to say, they enclose a space for the
reception of the electrode 4 and the electrolyte, this space, however, in the battery,
made in accordance with this invention, also serving for the reception of active
material or material to become active as hereinafter explained.
In preparing the battery any desired number of cells, or elements, of the
character described are combined in the manner shewn in Figures 1 and 2, that
is to say, they are confined by rubber bands 5, or any other available form of
elastic confining medium, between flanking plates 6, of hard rubber, vulcanized
fibre, acid proof wood, or other available material, the elements being separated
from each other by means of ribs 7, formed on the backs of the plate sections, the
ribs of the sections of one plate being preferably at right angles to the ribs of the
sections of the adjoining plate, so that free access of the electrolyte to the back of
each plate is provided for.
The battery thus prepared and having a metallic electrode inserted into the
spaces
between the porous plates of each element is then immersed in a suitable
.electrolyte and the current applied to the electrodes so as to effect the autogenous
formation of active material by electrolytic action upon the metal of the electrodes
in accordance with the Planté method, employing the well known methods of
accelerated formation until a sufficiently thick layer of active material has been
produced upon the electrodes.
Then (preferably without interrupting the forming process) metallic oxides are
introduced, preferably in the form of dry powder, into the spaces between each
electrode and the porous walls of its enclosing vessel until these spaces are com-
pletely filled with the oxide, the forming process being then continued until there

page_text: is a firm union of the active material thus introduced with the autogenously
formed active material upon the faces of the electrodes.
By this means a battery can be formed' almost, if not quite as cheaply as one
in which the active material is mechanically applied to the electrode preparatory
to the electrolytic action, and at the same fine the tendency of the battery to form
sulphate of lead between the electrode and the active material in discharging,
is prevented or very materially reduced, so that electrical results are obtained
approaching. very closely those of a battery formed wholly in accordance with the
Planté method:"
i th
Of course it will be evident that in carrying out this 'invention the form of cell,
vessel, or enclosure for the electrode may be largely varied, without departing
from the nature of this invention, the construction shewn being adopted because of
its simplicity, cheapness and convenience.
In Figures 1 and 2 I have shewn the electrode in the form of a flat metal plate,
but it may be preferable in many cases to use a waved,, or corrugated; plate; such
for instance, as that shown in Figure 7, in order to increase the surface of the pluto
exposed to electrolytic action.
H
The grooves formed in the sections of the supporting plates for the active
material are such as to laterally confine the strips inserted into them so that said
strips will be held in place when the plates are detached from each other and the
grooves formed in the sections of the plate extend from side to side of the same
and cross each other at the corners of the plate so that however, the sections of the
plate may be combined a groove will always be presented adjacent to each edge of
the completed plate.
By making the porous terra-cotta supporting plates for the active material in
sections very thin plates can be moulded and burned without risk of breaking,
warping, or other distortion, due to the burning of the plates, or to the handling of
the same before they are burned.
"
The small plates can be extremely thin and yet will, when moulded and burned,
be perfectly Hat, and they can, moreover, be moulded upon ordinary machinery
used in terra-cotta manufacture so that the bulk, cost, and weight of the supports
for the active material can be reduced to a minimum and plates of large area can
be used.
The different sections of the plate are free to move independently of each other,
and hence accommodate themselves to any irregularity of expansion, or contrac-
tion, of the active material, or to such buckling, or warping, as may take place,
in the conducting electrodes.
The sections of the plates may he so disposed that the vertical joints of one plate
will be out of line with the vertical joints of the adjoining plates if desired, but
this is not so important, as bringing the horizontal joints out of line, since active
material is not likely to accumulate upon the vertical edges of the plate sections.
The edges of the sections are preferably as wide as possible so as to provide good
bearing surfaces and prevent the sections from tilting on each other, and if
desired rabbeted edges may be used instead of plain edges.
aving now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. The process hereinbefore described of preparing a secondary battery clement,
the said process consisting in autogenously forming active material from the metal
of an electrode by electrolytic action, then loosely confining against the coated face
of the plate thus produced, granular, or pulverulent, active material, or material
to become active, and continuing the electrolytic action so as to effect the union
of this mass with the autogenously produced material on the plate, substantially
as specified.
°
2. A secondary battery consisting of a conducting electrode and a receptacle
therefor providing spaces between the electrode and the walls of the receptacle,

page_text: said receptacle consisting of opposite plates having their inner faces grooved in
proximity to the edges, and packing strips inserted in said grooves into which they
fit snugly so as to be laterally confined and thereby held in place when the side
plates are detached from each other, substantially as specified.
3. The hereinbefore described plate for supporting active material in contact
with the electrodes of an electric battery, the said plate having a surface recessed
for the reception and retention of the said active material, and having in proximity
to its edges grooves for the reception of packing strip or strips, which grooves
extend from side to side of the plate and cross each other at the corners of said
plate, substantially as specified.
4. A secondary battery consisting of a pair or of pairs of plates, the inner faces
of which are provided with pockets to which the active material is applied and by
which it is sustained in contact with the interposed conducting electrode, each of
the said plates being composed of a number of sections of stiff porous earthenware
disposed edge to edge, substantially as specified.
5. A secondary battery consisting of a pair or of pairs of plates, the rear faces
of which are provided with projecting ribs and their inner faces with pockets to
which the active material is applied and by which it is sustained in contact with
the interposed conducting electrode, each of the said plates being composed of a
number of sections of stiff porous earthenware disposed edge to edge, substantially
as specified.
6. A secondary battery in which are combined a series of pairs of supports each
having active material applied to its inner face and sustained thereby in contact
with the interposed conducting electrode, each of the said supports being composed
of a number of stiff porous earthenware plates disposed edge to edge, the horizontal
joints between the plates of one support being out of line with the horizontal
joints between the plates of the adjacent support,, substantially as specified:
Dated this 29th dov of 100
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.