Improvements in the Manufacture and Product on of Elements for Secondary Batteries, or Electric Accumulators.
Year: 1899

page_text: Date of Application, 3rd May, 1899
Complete Specification Left, 26th Jan., 1900-Accepted, 17th Mar., 1900
Improvements in the Manufacture and Product on of Elements for
Secondary Batteries, or Electric Accumulators.
I, HANS HERRMANN STRECKER, Ph.D., of 9, Friesenplatz, Cologne, in the German
Empire, do hereby declare the nature of this invention to be as follows:-
This invention relates especially to elements for secondary batteries, or electric
accumulators, wherein the active material, or material to be rendered active, is in a
mass within a frame as distinguished from elements wherein the said material is
held in grids; and the principal objects of this invention are to reduce the weight
and prevent warping of the plates during action.
According to this invention I omit the mid, or inner, portion of the plate (which
portion is less efficient than the outward parts, which are those active in the pro-
duction of the current) by forming an orifice through the material of the plate from
side to side, this orifice being surrounded by a frame of lead, or the like, and having
a groove in its outer periphery to hold the inaterial and the frame in position.
The said frame is divided or made in parts, so arranged as to enable them to yield,
sufficiently as the material expands. By this formation of the plate not only is that
portion of the material removed, which is practically but dead weight and which
especially causes warping, or bending, but, by the orifice, extra space for electrolyte
is gained and circulation is facilitated.
To enable the said frame to be arranged in place, the material should be introduced
in as dry a condition as possible, and the plate be formed without a drying process as
otherwise the mass of material would shrink and the frame would drop out of the
plate, and the plate would crumble to pieces.
The use of litharge alone has been objected to for positive plates, because of the
plates thus formed becoming too dense and hard, and of insufficient capacity and
becoming distorted during formation and therefore for positive plates minium alone
was used, a mixture of minium and litharge being used for negative plates. In the
reaction between minium, or litharge, and sulphuric acid, expansion in volume and
hardening take place, but minium, as usually sold, presents various chemical formulae
(mostly Pb, and Pb O₂) and this difference of formula, due to a more or less large
formation of sulphate, produces unevenness in the hardening and in the capacity of
the plates.
The difference in the reaction of various miniums with sulphuric acid is exemplified
in the formulae.
Before immersing the minium raw plates in sulphuric acid, it is necessary to care-
fully dry them, in order to prevent them from becoming disintegrated when put into
the acid. The drying process, however, causes an outer crust to be forined upon the
surface of the plates (especially when organic matter is also introduced) the early.
crumbling of which, in the course of working, leads to inconveniences and initiates
the decay of the plates.

page_text: Instead of using minium I use a mixture of litharge with so much carbonate of
lead, that the expansion of this mixture during the reaction with sulphuric acid,
becomes equal to the expansion, which minium of the formula Pb,, would undergo
during hardening. As the carbonate of lead, during its conversion to sulphate of
lead, is not subject to increase in volume, an addition of such carbonate to the
litharge has a diminishing effect upon the whole volume of the mass. A suitable
mixture is from 85 to 92 parts litharge to from 15 to 8 parts of carbonate of lead.
The mixture is.then very slightly inoistened with a weak alkaline solution and
kneaded into the frane, in the centre of which the aforesaid inner frame is situated
and in order to prevent the formation of a crust, the raw plates thus produced, are,
with the least possible delay, formed in an acidulated salt solution such as a solution
of sulphate of sodium or sulphate of potassium, ammonium, or magnesium, acidulated
with sulphuric acid..
Improvements in the Manufacture and Production of Elements for
Secondary Batteries, or Electric Accumulators.
I HANS HERRMANN STRECKER, Ph.D., of 9, Friesenplatz, Cologne, in the German
Empire, 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 :-
This invention relates especially to elements for secondary batteries, or electric
accumulators, wherein the active material, or material to be rendered active, is in a
mass within a frame, as distinguished from elements wherein the said material is
held in grids; and the principal objects of this invention are to reduce the weight
and prevent warping of the plates during action.
According to this invention I omit the anid, or inner, portion of the plate (which
portion is less efficient than the outward parts, which are those active in the
production of the current) by forming an orifice through the material of the plate
from side to side, this orifice being surrounded by a ring, or frame, of lead, or the
like, having a groove in its outer periphery so that the material and the frame are
held in position.
The said frame is divided, or made in parts, so arranged as to enable them to
yield sufficiently as the material expands. The accompanying drawing illustrates in
face view in Figure 1 and in cross section in Figure 2 a construction in accordance
with my invention, A being the active material of the plate, or material to be
rendered active, and the orifice in the mid portion. bis the surrounding frame
and c c¹ the parts of the ring, or frame, surrounding the orifice u, as aforesaid, with
sufficient space between the said parts to enable them to yield sufficiently. By this
formation of the plate, not only is that portion of the material removed which is
practically but dead weight and which especially causes warping, or bending, but,
by the orifice, extra space for electrolyte is gained and circulation is facilitated.
To enable the said frame to be arranged in place the material should be introduced,.
in as dry a condition as possible, and the plate be formed without a drying process,
as, otherwise, the mass of material would shrink and the frame would drop out of
the plate and the plate would crumble to pieces. The use of litharge alone has
been objected to for positive plates, because of the plates thus formed becoming too
dense and hard, and of insufficient capacity and becoming distorted during formation

page_text: and therefore, for positive plates, minium alone was .used; a mixture of minium
and litharge being used for negative plates. In the reaction between minium, or
litharge, and sulphuric acid, expansion in volume and hardening take place, but
minium, as usually sold, presents various chemical formulæ, (mostly Pb,O, and Pb,O),
and this difference of formula, due to a more, or less, large formation of sulphate,
produces unevenness in the hardening and in the capacity of the plates.
The difference in the reaction of various miniums with sulphuric acid is exem-
plified by the formulæ :
ԿԱՆ
places in surpuric acid it is necessary to
carefully dry them, in order to prevent them from becoming disintegrated when put
into the acid. The drying process, however, causes an outer crust to be formed upon
the surface of the plates, (especially when organic matter is also introduced) the early
crumbling of which, in the course of working, leads to inconveniences and initiates
the decay of the plates. Instead of using minium, I use a mixture of litharge with
so much carbonate of lead that the expansion of this mixture, during the reaction
with sulphuric acid, becomes equal to the expansion, which minium of the formula
PbO, would undergo during hardening. As the carbonate of lead, during its
conversion to sulphate of lead, is not subject to increase in volume, an addition of
such carbonate to the litharge has a diminishing effect upon the whole volume of the
mass. A suitable mixture is from 85 to 92 parts of litharge to from 15 to 8 parts of
carbonate of lead. The mixture is then very slightly moistened with a weak alkaline
solution and kneaded into the frame, in the centre of which the aforesaid inner frame
is situated and, in order to prevent the forination of a crust, the raw plates, thus
produced; are, with the least possible delay, formed in an acidulated salt solution,
such as a solution of sulphate of sodium, or sulphate of potassium, ammonium, or
magnesium, acidulated with sulphuric acid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what
I claim is
'
1. Elements for secondary batteries, or electric accumulators, having the central
portion removed, and having inserted into the opening thus formed a divided ring, or
frame so as to reduce the weight, and prevent warping of the element, and ensure an
effectual circulation of the electrolyte; substantially as hereinbefore described.
2. The manufacture of positive plates for secondary batteries, or electric accumula-
tors, from a mixture of litharge, and carbonate of lead, forming a mass, the expansion
of which, in the electrolyte, corresponds to the expansion of minium of the
formula Pb,O, under the, saine action this mass being slightly moistened with a dilute
alkali solution and applied to a frame and, while still in a moist condition, and without
drying, formed in an acidulated salt solution (preferably in an acidulated solution of
a sulphate of an alkali) so as to obtain a positive plate of practically uniform capacity,
and without a crust upon the surface, an opening with a ring, or frame, being arranged
in the mid part of the element for preventing the mass from becoming disintegrated.
Dated this 26th day of January 1900.
JOHNSONS & WILLCOX;
47, Lincoln's Inn Fields, London, W.C., Agents.