IMPROVEMENTS IN ELECTRICAL ACCUMULATORS OR SECONDARY BATTERIES A
Year: 1883

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake,
"
and Co, Patent Agents, Southampton Buildings, London for an Invention
of "IMPROVEMENTS IN ELECTRICAL ACCUMULATORS OR SECONDARY BATTERIES
A communication to him from abroad by Nathaniel Shepard Keith of the
City and State of New York United States of Amerion.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 2nd March 1883.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN ELECTRICAL ACCUMULATORS
OR SECONDARY BATTERIES Communicated to me from abroad by Nathaniel
Shepard Keith, of the City and State of New York, United States of America.
"
This invention relates to that class of secondary batteries commonly known as
the "Planté" battery, inasmuch as it depends upon oxidation and reduction of
lead.
The said invention has for its object to reduce the cost, facilitate the manufacture,
and increase the electrical efficiency and capacity, and other desirable practical
requirements, of the said batteries.
The said invention consists essentially in the combination of a positive electrode,
the active part of which is finely divided metal deposited thereon by electro-
deposition, and a negative electrode the active part of which is a spongy metallic
compound deposited thereon by electro-deposition, either one or both electrodes
being contained in a porous envelope or receptacle.
In the accompanying drawing.
Fig. 1 is a vertical longitudinal section of a battery cell constructed according to
this invention.
Figure 2 is a plan showing the arrangement of four cells in a group.
A is the terminal of the wire which connects all the plates or electrodes of one
kind, and B the terminal of the wire which connects all the plates or electrodes of

page_text: '
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the other kind, in the manner well known as for "quantity" or "multiple arc in
ordinary galvanic batteries. d indicates the conducting core or lead plate; e a
porous envelope (in this case having the form of a bag) and f the spongy material
either metallic or oxidized.
G, D, E, and F in figure 2 represent four such cells the plates in each of which
are arranged for "quantity" while the cells are placed in series, after a well known
arrangement. A and B represent the terminals of the circuit, and the arrows the
direction of the current when receiving the charge, which direction is reversed
during the discharge.
The efficiency and capacity of a secondary battery of this kind depends upon the
amount of porous, or spongy metallic lead, as well as upon the amount of similarly
constituted lead oxide which can be placed and retained in contact with the surfaces
of the plates or other forms of materials which are used to support these spongy
materials or contain them.
In practice, any desirable amount of either spongy lead-oxide, or spongy metallic
lead, can be deposited upon electrodes by electrolysis, or rather semi-electrolytic
action in certain kinds of solutions of lead, and these deposits may be kept upon
the electrodes by enveloping them in bags, wrappers, cases, cells or equivalents,
either before or after the formation of the spongy deposits, and the electrodes so
prepared are very effective in secondary batteries.
In carrying the said invention into practice I take a solution of some salt of lead,
such as the acetate or the nitrate, which solution must be either neutral, or
preferably alkaline, in its reaction, and use that for a bath, in which I suspend two
or more sheets or other forms of lead as electrodes connected in alternate order with
the positive and negative poles of a source of electricity.
These solutions are imperfect electrolytes, that is to say, they do not allow of
perfect electrolysis; but instead of dissolving the anode and depositing metallic
lead upon the cathode as in true electrolysis, oxides of lead are formed upon both
the positive and negative electrodes.
It is necessary to use for the formation of these deposits, solutions of lead which
suffer decomposition under an electric current, such as the neutral or alkaline
solutions of nitrate, chloride, or acetate of lead, or those salts called the "plumbates,"
either in water alone or in solutions of other salts.
I enclose the electrodes in bags, or other containers, made of fibrous material;
which will allow the passage of the electrolyte through their meshes, but will also
retain the oxides in contact with the electrodes which they encase.
This I do before placing the electrodes in the electrolyte and before connection
is made with the source of electricity; and I retain the bags upon the electrodes
for the purpose of keeping the deposits upon the different electrodes from
mixing.
As the deposits are coherent, I sometimes dispense with the bags while making
the deposits, and place them on the electrodes after the deposits are formed.. In
this manner any desirable thickness of oxides of lead deposits may be formed.
After passing electric currents through such an arrangement of lead electrodes
and solution, if the source of electricity be removed and the lead electrodes be
electrically connected, a current of electricity. will flow through the electrodes
(composed of the plates or supports) solution, and conductor, but in the opposite
direction to that from the original source.
The duration of this return current is in proportion to the amount of oxides
which have been deposited on the electrodes, so it is desirable to continue the
original current of electricity as long as it may be found practically expedient, in order
to have as much of the oxides, as possible on the supports and in the containers.
Probably the deposit made by my invention on the negative electrode is a sub-oxide
of lead, while that upon the positive electrode is the per-oxide, or a super-oxide of
lead, but as lead suffers so many degrees of oxidation, the exact degree which takes
place in every case cannot be positively determined.
Under the conditions of action, as a battery, the electrodes having the sub-oxide

page_text: are electro-positive to those having the super-oxide, consequently an electric current
flows, when an electric circuit is made connecting the two kinds of electrodes.
It will be noticed, that: the electrodes which are electro-positive while under the
action of an external source of electricity, become, electro-negative when the source
is disconnected; and the same, conversely, with the opposite electrodes.
In order to increase the electro-motive force of such a battery, I take the
lectrodes prepared as herein before described and immerse them in a conducting
liquid in which lead is nearly, and preferably quite, insoluble; a mixture of one part
of sulphuric acid with ten or twelve parts of water answers the purpose very well.
If the electrodes have retained their positive and negative relation a current
will flow as before, until the deposits of both kinds have assumed the condition of
protoxide.
If a current of electricity is passed through this arrangement, the oxide on the
electrodes in connection with the positive pole of the source of electricity will be
super-oxidized, or per-oxidized, and those in connection with the negative pole will
be reduced to a metallic condition. These electrodes thus again assume a relative
positive and negative condition which causes a current of electricity to flow through
a galvanic circuit of which they form a part.
I sometimes form electrodes by the following process, that is to say by depositing
finely divided crystalline, metallic lead upon plates of lead, and subsequently
oxidizing the deposits on those to be used as the negative electrodes of a secondary
battery by electrical action, in the manner herein before described.
For the purpose of increasing the electro-motive force of the electrodes I arrange
a number of them in a series of vats, or cells, placed in immediate continuity, so
that the current flows from the electro-negative electrodes of one cell to the electro-
positive electrodes of the next cell, and so on through the series, in a manner analogous
to connecting galvanic batteries.
An efficient equivalent of this last arrangement is obtained by making one large
cell and dividing it into the desired number of small cells by water-tight non-
conducting partitions, and connecting the electrodes as before described.
I am aware that oxides have been formed upon lead electrodes by the action of
electricity notable in the case of the well known "Planté" secondary battery; but
such oxides were formed from the lead of the electrodes themselves, by decom-
position of water on their surfaces, and not, as according to this invention, deposited
from a solution of lead, in which the electrodes are immersed.
In the case of the "Planté " battery, the oxide is formed in sufficient quantity for
even small uses, only after very many charging and discharging operations,
necessitating time and expense.
By means of this invention, the electrodes are formed or prepared to any degree
of efficiency, during one operation.
Having thus fully described the said invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim.
In a secondary battery, the combination of a positive electrode, the active part of
which is finely divided metal deposited thereon by electro-deposition; and a negative
electrode, the active part of which is a spongy metallic compound deposited thereon
by electro-deposition, either one or both electrodes being contained in a porous
envelope or receptacle.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this second day of March in the year of our Lord One
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