Improvements relating to Secondary or Storage Batteries.
Year: 1890

page_text: Date of Application, 21st Jan., 1890-Accepted, 22nd Feb., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by THOMAS EWING, of the City and State of New York,
United States of America, Counsellor at Law.]
Improvements relating to Secondary or Storage Batteries.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent Agents
Southampton Buildings, in the County of Middlesex 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 :-
The invention relates to the electrodes of a secondary or storage cell and consists,
first, in an electrode in which the active material is massicot, and second, in a
method of treating a storage battery electrode so as to prevent the disintegration,
detachment, or blowing out of the active material therein while in the electrolyte.
It is a well-known fact, that the active material in a storage cell, is subject to
expansion and contraction during certain phases of the operation of the cell, and that
the effect of this constant change. of form of active material, is greatly to reduce the
effective life-time of the elements. When the active material is placed in the
openings or interstices of an otherwise solid plate, the effect of its expansion is either,
to deform the plate, or else to tear it. On the other hand, in contracting the active
material is apt to become loosened and fall out of the cavities in which it is packed,
and this is especially the case after previous expansion. The result is, that the plate.
either disintegrates, or at best, buckles or bends, so that when several plates are
disposed in close proximity in the cell, this bending or change of form may easily,
result in contact, and short circuiting between them. Various attempts have been
made to overcome these difficulties by special construction of the supporting bodies or
plates of electrodes, notably by the formation of apertures essentially of different
shapes, in arrangement, and by making the plates of alloys and materials compounded
with lead or other than lead, with the object of getting increased strength and
augmented surface.
Of the various active materials used in the cell, the oxides of lead are the most.
common. There are five known lead oxides, as follows: lead Sub oxide, Pb, O
lead, Monoxide, Pb O, lead Sesqui oxide, Pb, O2, Triplumbic Tetroxide, Pb. O,
and lead Dioxide, Pb O₂. Of these five oxides, Monoxide, Tetroxide, and Dioxide,
or as more commonly called, Litharge, Minium, or red lead, and lead peroxide, or
brown oxide of lead, have all been used as active material in the storage battery.
But as is well known, there are two forms of lead monoxide, one being known as
massicot, and produced by the oxidation of metallic lead in a current of air, and the
other a substance yielding on fusion a crystalline mass, and produced by the oxida-
tion of metallic lead at a higher temperature than that which is required for the
manufacture of massicot. This last is litharge. So far as is known, massicot has not
been employed as an active material in the storage battery; and in fact, it finds
but very few uses in the arts. It appears, however, that when massicot is used as
such active material, it possesses properties different from any other lead oxide or
form thereof, and in fact, from any other and different material employed for the
same purpose. It has been found, that if two plates of like construction are packed
the one with massicot and the other with litharge, for example, the plate packed with
massicot will not undergo deformation in the cell, while the plate packed with
The bodies of
litharge, under similar conditions, will be more or less distorted.
massicot still remain firmly coherent in the plate under conditions when like bodies
of litharge or lead peroxide, will loosen and fall out. It appears, moreover, from experi-
ment, that massicot has in the storage cell, a rate of expansion and contraction very
closely approximating to, if not the same, as that of lead itself. And hence, when

page_text: massicot is placed in a lead plate, both the lead and the active material apparently
expand and contract coincidently, and therefore, maintain their relative relations in
point of volume; and hence, do not tend to separate or disintegrate. The massicot
may be applied to the plate in any desired way, that is, it may be packed therein
dry under pressure, or it may be made into pasty mass, and then inserted. It
materially increases the storage capacity of the cell.
When the support or grid is packed with active material in a dry and pulverized
state, and then placed suddenly in the electrolyte, gas forms between the particles of
said active material and blows out or detaches the same from the support. This
difficulty is to some extent prevented by making said active material in the condition
of a paste or cement, and packing it into the plate while moist, and allowing it to
harden there; but if the mixture is imperfect throughout the mass, more or less gas
will be formed, or more or less confined air will be present, and the disadvantageous
results above noted, will be produced. By the mode of treating the electrode herein-
after described, a perfectly dry powder may be packed into the grid or support;
which powder may be massicot or other suitable active material, and the electrode
may be at once immersed in the fluid in the cell in which said electrode is to be
used. The active material is packed in the plate by hydraulic, hand, or other suit-
able pressure. The plate is then placed in the cell in which it is to be used, and the
electrolytic liquid is poured slowly into said cell, or conducted therein by a siphon
tube reaching nearly to the bottom of the cell. Or instead of first placing the
electrode in the cell, the electrolytic liquid may in the beginning be introduced, and
then the plate is slowly lowered into the liquid. This slow and gradual immersion of
the packed plate is essential and its result is the complete prevention of the detaching
or disintegration of the active material by the action of contained air or generated
gas. Instead of the air or gas being imprisoned in the active material as is the
case when the plate is, as it is commonly, rapidly immersed in the liquid, the gradual
and slow immersion of the plate allows time for the thorough infiltration of the fluid
and the gradual expulsion of air or escape of gas from the mass of active material
as the liquid level on the plate rises.
The rate at which the liquid should be allowed to cover the plate is easily
determined by experiment for plates of any given dimensions. If the immersion is
too rapid, the active material will be seen to disintegrate, but this effect will cease as
soon as the immersion is reduced to the proper speed. After that point is reached,
greater slowness is immaterial and usually advantageous. As soon as the plate is in
the proper place in the cell, the latter may be at once used, and the ordinary charging
operation proceeded with.
While, as already stated, the charging of the electrode may take place in the same
fluid in which it is slowly immersed, this is not essential to the invention, because, if
desired, the electrode may be immersed in a separate fluid, and then removed there-
from, and subsequently placed in the battery fluid in which it is to be used. It has
been found in practice that the liquid should be allowed to rise on the plate, or the
plate should be lowered into the liquid previously in the cell at the rate of about six
inches per minute. This is the fastest rate of speed: a slower rate is, however,
beneficial or in other words, the result will be better the more slowly the
immersion takes place, and therefore, the time may be increased to one or two hours
with advantage.
:
By the term "immersion" herein used is meant either the gradual and slow
insertion of the electrode into the liquid, or the gradual and slow rising of the liquid
introduced into the cell around the previously introduced electrode.
Having now fully described and ascertained the nature of the said invention and
in what manner the same is to be performed, as communicated to me by my
foreign correspondent 1 declare that what I claim is :-
1. A secondary or storage battery electrode containing active material consisting of
massicot.

page_text: 2. A secondary or storage battery electrode comprising a support of lead or lead
alloy, and an active material consisting of massicot applied to or packed in said
support.
3. The method of treating storage battery electrodes by first applying active
material to or packing said material in a support, and then slowly and gradually
immersing said support in an electrolyte.
4. The method of treating storage battery electrodes by first applying active material
in a dry, pulverulent state to or packing said material in, a support, then gradually and
slowly immersing said electrode in an electrolyte, and then charging said electrode in
said electrolyte.
Dated this 21st day of January 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.