Improvements in Electric Accumulators or Secondary Batteries and in the Manufacture and Production of Plates or Elements therefor.
Year: 1890

page_text: Date of Application, 3rd June, 1890-Accepted, 5th July, 1890
CONTIERE SIMULTA
Improvements in Electric Accumulators or Secondary Batteries and
in the Manufacture and Production of Plates or Elements
therefor.
1 JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been
communicated to me from abroad by Carl Hering of 48 rue de Bondy Paris
in the Republic of France Engineer) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
--
This Invention has for its object the production of electric accumulators or secondary
batteries in which the positive and negative plates are composed entirely of active
material. These plates acquire by the operation of the process hereinafter
described a degree of consistency, strength and porosity which enables them to be self
sustaining without requiring lead supports; they are not subjected to the destructive
action of expansion and contraction and are readily oxidised and reduced throughout
their entire mass.
The invention relates chiefly to a method of preparation consisting essentially in
employing a soluble salt of lead as the binding or cementing agent of the pulverulent
oxides.
It is found that the salt of lead best suited for this purpose is the acetate by means
of which a more perfect adhesion of the particles of oxide is obtained than is possible
with any other salt.
The principal difficulty in the manufacture of these plates is to make them porous
so that they may form more equally throughout and may not be liable to crack,
swell, exfoliate or present other than a smooth surface whilst they are being
formed.
To overcome this difficulty the oxides of lead usually employed are mixed with
a reducible mixture, a salt or oxide of lead, of such a nature that when they are
converted into peroxide by the electrolytic action their volume is reduced and they
occupy a smaller space. A space or porosity is thus formed about or in contact with
the peroxide.
The area of exposed surface of the electrode is increased by pricking or perforating
the moulded plastic material.
To render the plates harder and stronger before placing them in position they may
be immersed in sulphuric acid. The duration of such immersion is regulated
according to the degree of hardness which it is desired to obtain.
If the mixture composing the said plates before the forming process does not
contain any good conducting material they will form slowly and with difficulty. On
this account it is preferable to mix peroxide of lead with the other elements composing
the material for the plates.
:-
It is preferable to make the plates of peroxide in the following manner, namely
a dry mixture of peroxide, minium or red lead and carbonate (or sulphate) of lead in
powder is mixed with a solution of acetate of lead to the consistency of a firm
paste. This mixture is afterwards compressed in a mould and pricked or perforated
at several points, after which it is dried in a furnace.
It may then be hardened by immersion in sulphuric acid after which it is placed in
position and subjected to the forming process.
The invention is not limited to the employment of carbonate or sulphate of lead in
the manufacture of the plate as aforesaid it being evident from the principle of the
invention that any other salt may be substituted which when converted into peroxide
by the electrolysis will occupy less space than it did before.

page_text: The plates may moreover be strengthened and hardened by a treatment, consisting
in plunging them into a solution of a salt or compound of lead, such for example
as acetate of lead, then drying them and afterwards forming them again with the aid
of a positive current in the usual manner.
This may be repeated as frequently as may be desired and imparts to the plates the
required degree of hardness and density.
With this treatment the soluble salt of lead forms on drying a thin covering of
crystals at the surface of the porous spaces. During the conversion into peroxide
the dimension of the porous spaces diminishes without reduction of their number.
-
If it be desired to further strengthen the plates and render their surfaces very hard
they are electrically covered, after they are formed, with peroxide of lead being
supported in a bath of a soluble salt of lead such as the nitrate.
At the same time a suitable cathode is caused to act in the bath by causing an
electric current to pass in this cathode and using the plates as the anode. The plates
then become covered with a layer of deposited peroxide of lead which is almost as
bard as highly tempered steel.
The cathode of the secondary battery is made in the same manner as the anode or
in the following manner, namely, a quantity current is caused to pass in an acid bath
composed of a soluble salt of lead such as the nitrate for example.
The anode in this bath is formed by a plate of lead and the cathode is of any suitable
material preferably of pointed pieces of lead or lead wire. Arborescent cystals of
lead then form in large quantities at the cathode. These crystals are extremely fine
and when recently formed possess the property of adhering to one another or of
uniting together when powerfully compressed forming a very porous and very
tenacious mass which is malleable, flexible and fibrous and resembles a textile material.
These crystals are collected together and kept under water until a sufficient quantity
is obtained to form a plate. They are then placed in a mould and subjected to
sufficient pressure to cause them to adhere together.
After washing the plate is ready for being employed in an accumulator without
requiring further charging. A porous and strongly coherent plate of finely
divided lead is thus obtained which works admirably well as a plate in a secondary
battery.
Figure 5 of the accompanying drawings indicates the principle of the accumulator
constructed with unperforated plates prepared as herein before described.
The positive plates are separated from the negative plates by sheets i of insulating
material. All the plates are represented as being united by one insulating bolt A
passing through the mass. The nuts on this bolt bear on compressing plates B. The
current is taken off by the conductors C. C, D D. This illustration of the battery
in its simplest form enables the construction of the accumulator to be understood,
other forms of construction such as are actually employed in practice are illustrated
in the other figures hereinafter described.
E are
Figure 1 represents in elevation, one mode of constructing the accumulator:
Figure 2 illustrates the same arrangement in plan. The plates of active material are
marked A, the conducting plates are marked B and the non conducting plates or
sheets are marked C. Dare conductors to which the plates B are connected.
pressing bolts of non-conducting material. F are the pressing plates also of non
conducting material. A portion of the plates is represented as being broken away
at M N figure 1 so as to show the arrangement of the holes or perforations for the
circulation of the liquid through the super posed plates. In figure 2 also the plates F A. B
are partly broken away so as to show the orifices for the circulation of the liquid
in the body of the combination. Figures 4 and 4ª illustrate in section and in
half plan respectively a peculiar form that may be given to the non conducting
plates.
Figure 3 illustrates a peculiar arrangement of the active elements which enables
the number of lead conducting plates to be reduced by arranging two positive plates
alternately with two negative plates as indicated in this figure it being sufficient to
place the lead plates between the negative elements.

page_text: Figure 6 illustrates in sections taken in four different horizontal plans an accumu-
lator constructed according to this Invention. A compressing plate F is indicated
in the section at 1; the section 2 shows the active material A, the section
at 3 shows the conducting plate B and the section at 4 shows the insulating
plate C.
The homogeneous plates composed entirely of active material are obtained by
means of the process hereinbefore described. On one side or on the two sides of
each plate is placed a sheet of lead or other conducting material for the passage of
the current.
This combination forms one complete plate.
These plates are then separated from those of opposite polarity by their sheets of
any porous elastic or other non conducting material, such as celluloid, paper parch-
ment, porous porcelain, gutta percha, flexible or hardened india rabber or caoutchouc
or the like.
A series of plates thus prepared is placed between two rigid plates of porcelain,
ebonite glass wood treated with paraffin or other analogous inaterial which are
connected and pressed or drawn together by bolts or otherwise.
This series of plates is thus firmly secured and forms a solid block.
The discharge from the plates takes place principally at their edges. To increase
the discharging surface the plates are perforated with holes extending from one flat
side to the other. The non conducting material separating two adjacent plates of
opposite denomination is perforated with holes corresponding to those in the
plates and this enables the discharge to take place equally at the interior of the
latter.
This mode of construction enables the plates to expand and contract in the direction
of their length or of their width without injuring or destroying their metallic
conductor or losing contact therewith.
The positive plates can likewise expand in the direction of their thickness owing
to the softness and elasticity of the negative plates. The plates are not liable to twist
or buckie and lose their shape and even if there were a tendency to get out of
shape it would not prejudice the action of the accumulator or bring the plates in
contact with one another.
The active material also cannot lose contact with the conducting plate being always
firmly sustained by the pressure of the bolts. This pressure can moreover be
moderated and regulated by placing a ring or washer of elastic material such as
india rubber under the nuts of the bolts.
In order to prevent the active material from establishing a contact between the
plates over the edges of the sheet of celluloid or other separating material
employed this sheet is made somewhat wider than the plates and the holes with which
it is perforated are made somewhat smaller than those in the plates as represented in
the drawing.
The same result can be obtained by taking thicker sheets of celluloid or the like and
turning up the edges as indicated in figures 4 and 4ª. In order to retain and stop the
small pieces of active material that might become detached at the corners or angles
the edges of the celluloid may be further bent or doubled back so as to form a species
of box enclosing the plate.
It is evident that many modifications may be introduced into this general
arrangement for example the plates in place of being arranged horizontally as repre-
sented in the drawing may be placed vertically or inclined. The holes may be of any
shape or dimensions. The thickness of the active plates and the number of contact
plates may be regulated according to requirements. The plates may be alternately
positive or negative but several positive plates may be put together alternately with
several negative plates as represented in Figure 3.
The material separating the plates may be a non porous substance such as celluloid
or it may be composed of a porous substance thus enabling all the surfaces in contact
therewith to become active surfaces.

page_text: By means of this arrangement of the plates it is evident that if the metallic conductor
becomes corroded it can he readily changed and renewed.
It is likewise evident that in order to obviate the necessity for making very large or
wide plates several small blocks of plates can be placed in the same trough or receptacle
the connections being established in the same manner as in the case of a single
accumulator.
Having now particularly described and ascertained the nature of the said Invention
and in what manner the same is to be performed. I declare that what I claim, is :-
1. A material for use as the active element in a secondary battery consisting of
oxide of lead, a soluble salt of lead and a reducible oxide or composite salt of lead of
such a character that its volume diminishes when it is converted into peroxide by
electrolysis substantially as herein before described.
2. A meterial for use as the active element in a secondary battery consisting of
insoluble compounds of lead and acetate of lead substantially as hereinbefore
described.
3. As a new product of manufacture a plate for a secondary battery consisting
of a mixture of oxide of lead and a soluble salt of lead with a reducible oxide or
composite salt of lead of such a character that it occupies less space or volume when
converted into peroxide by electrolysis the whole being arranged to constitute an
electrode ready for the forming process substantially as herein before described.
4. As a new product of manufacture an electrode for a secondary battery consisting
of a mixture of an oxide and a soluble salt of lead compressed in a mould perforated
and dried or dried and perforated the whole being arranged to constitute an electrode
ready for the forming process substantially as hereinbefore described.
5. As a new product of manufacture an electrode for a secondary battery consisting
of a moulded porous plate of peroxide of lead containing in its pores crystals of a
soluble salt of lead.
6 An accumulator or secondary battery consisting of positive and negative plates of
active material each active plate being provided on one or more sides with a conducting
plate maintained in contact with the active plates by pressure the plates of opposite
polarities being separated by a sheet of non conducting material and the entire series
of plates in the battery being firmly secured by pressure so as to constitute a solid
block substantially as hereinbefore described:
7: An accumulator. consisting of positive and negative plates of active material
presenting numerous holes each plate being provided on one or more sides with a
conducting plate 'maintained by pressure in contact with the active plate the plates of
opposite polarities being separated by sheets of non conducting material perforated
with holes which coincide or correspond with the holes in the plates the entire series
of plates being firmly maintained by pressure in such a manner as to form a solid
block substantially as hereinbefore described.
8. An accumulator consisting of positive and negative plates of active material
presenting numerous holes each plate being provided on one or more sides with a
conducting plate maintained in contact with the active plate by pressure the plates of
opposite polarities being separated by a sheet of non conducting material perforated
with holes which coincide or correspond with but are of smaller dimensions than the
holes in the plates, the entire series of plates being firmly secured by pressure in such
a manner as to form a solid block substantially as hereinbefore described.
9. In an electric accumulator a separator for the active plates the said separator
not being a conductor and being perforated with holes substantially as hereinbefore
described.
10. In an accumulator a separator of porous or other non conducting material
between positive and negative plates having its edges turned up so as to form a species
of shallow box or tray for the reception of the active material substantially as
herein before described.
11. In an accumulator consisting of perforated plates of active material a separator

page_text: of porous or other non conducting material arranged between the positive and negative
plates and provided with corresponding holes the outer edges of the said separator as
well as the edges of the holes being turned up so as to form a species of shallow box
or tray for the reception of the active material material substantially as herein before
described.
This 2nd dow of Tune 1900