Improvements in Primary Batteries or Cells.
Year: 1897

page_text: Date of Application, 15th June, 1897-Accepted, 28th Aug., 1897
Improvements in Primary Batteries or Cells.
I, ISIDOR KITSÉE, of 306 Stock Exchange Place, Philadelphia, Pennsylvania,
United States of America, Analytical Chemist and Electrical Expert, 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:
My invention relates to primary batteries or cells and more especially to those
of the single-fluid type.
The invention refers more especially
1. To the mode of making or preparing the positive or zinc element.
2. To the mode of making or preparing the negative or depolarizing element.
In primary batteries or cells the selection of the electrolyte is of great import-
ance, for the reason that the resistance of the different liquids greatly vary,
sulphuric acid having the lowest resistance, would be preferred, but for the reason,
that zinc which is usually employed as the dissolving agent in such cells, has too
great an-affinity for the acid and dissolves even if the circuit is not closed.
Different methods have been employed to overcome this difficulty, but I have
found that the one, hereinafter described has the great advantage of simplicity,
compactness and durability over the others known or described..
As to the negative or depolarizing element, I have found that a salt of lead,
brought to a high state of oxidation, is well adapted for its purpose, but economy
bars the employment in primary cells of oxidized lead, not only for the reason
that the charging if done electrically of each element separate, requires an
unnecessary amount of labour and handling, but also for the reason that where
oxidized lead is exposed to the action of sulphuric acid, after being partially dis-
charged, a slow sulphating takes place, resulting in the destruction of the element.
In my experiments, I have placed at different points batteries of different
constructions, having more or less of the oxidized lead exposed to the electrolyte
and invariably a local action between the lead and the depolarizing element took
place after partial discharge, if the battery was idle for about one or two weeks.
I have carefully examined such batteries and always found the oxidation of the
lead more or less sulphated.
Taking apart the element I found a difference of over 1/2 of 1 volt between the
lead and the depolarizing element.
An element, therefore, which is so constructed as to expose part of its conductor
to the electrolyte, cannot be effectually used in primary cells employed for open
circuit work.
It is therefore necessary to surround the conductor proper entirely with a mass,
and a very compact one, of a high oxide.
But repeated experiments have proved that it is hardly possible to compress a
solid mass of low oxide around a conductor and electrically charge the so compacted
mass to the point of highest oxidation, without breaking or cracking the mass in
the process of formation.

page_text: In my experiments, I have repeatedly manufactured such elements with the
greatest possible care, using a very slight current at the beginning, and discharging
every third day of the charge, so that nearly one month was consumed in bringing one
set of such elements to the required standard, and yet, it was not possible to attain
perfect success, cracking and breaking up could not be entirely avoided.
For this and other potent reasons I have recourse to the method hereinafter
described.
Referring to the accompanying drawings in which similar letters indicate
similar parts:
Figure 1 is a vertical section of my apparatus, and
Figure 2 is a section on the line of Figure 1.
A is the containing vessel, preferable of cylindrical form, so that the cap can be
screwed to the top of the jar, thereby making an air-tight joint, which is of
advantage to prevent a great deal of evaporation and creeping of salt.
B is the cap or cover being screw-threaded as shown at a.
D is the positive or zinc element as an entirety, of which D₁ is the supporting
conductor in the shape of a rod, preferable of copper, F¹ the element proper con-
sisting of an amalgam of zinc and mercury, or lead and mercury as the case may
be, F the cup containing the compound Fi, a rivet-head F3 or other protuberance
preventing the rod D' from slipping through the orifice of the cup F, F³ cement
surrounding the lower part of said cup.
The modus operandi of preparing the element is the following:
A cun, preferable in the shape of a round vessel, one inch in diameter by two
inches high is provided at its bottom with an orifice large enough for the con-
ducting rod to pass through; the lower part of the rod is flattened or provided
with a washer, so that when placed in position as shown in Figure 1, it is prevented
from slipping through the cup. The cup is made of wood or other suitable inert
material.
The compound in a molten state is poured into the cup filling it entirely. After
cooling, the lower part of the filled cup is then dipped into a cement so as to seal
its perforated bottom effectually.
In my experiments I have found that such is a necessary precaution as otherwise
the mercury, which becomes free through the dissolving of the zinc or sulphating
of the lead, due to the action of the electrolyte if the battery is working, may ooze
out through the perforated bottom.
The cement, preferable consists of equal parts of rosin and pitch intermixed with
a small proportion of wax.
I am aware that, as for instance in the so-called Fuller, or like cells the positive
or zinc element is placed in connection with free mercury in a receptacle, but such
is not my intention.
Having found that elements of such description do not work well, and are not
easily transportable, I had recourse to the method as above described, in which the
whole mass is, as an entirety, poured in its molten state into the cup, filling the
same entirely with one solid mass, no free mercury being present.
In following out this method or process the sole and only object is to practically
make out of the three parts, the conductor, the metal and the cup, one mechanical
unit, which mechanical unit I am aware may also be established by first casting
the metal and then providing the metal with a tight fitting cup, but I have found
that in my experiments such requires great care and that even the slightest space
between metal and cup is a disadvantage.
D2 is the negative or depolarizing element as an entirety, D³ is the conductor
proper, E is the depolarizing compound and E2 the non-conducting envelope
surrounding the compound, the conductor D³ is at its lower end provided with the
enlargement d¹.
Rubber bands e, preferable surrounding the compound and its envelope.
The method of preparing this element is as follows:

page_text: A salt of lead, preferable a low oxide is in bulk, brought to the highest state of
oxidation preferable through the action of an electric current. The high oxide is
then powdered and in suitable moulds, provided with conducting rods, packed
around said rod under high pressure.
It is preferred to make the conducting rod about 3/8 inch and the surrounding
mass about 5/8 inch in diameter.
As mentioned above, it is of great importance that no part of the conductor shall
be in direct contact with the electrolyte and therefore the depolarizing mass should
surround the conductor entirely so far as the conductor is designed to be immersed
in the electrolyte.
In my experiments I was a great deal annoyed by the fact that the compressed
depolarizing compound commenced to drop off as soon as the outside circuit was
closed, which very often resulted in the entire disintegration of the whole element.
A low oxide such as red lead, or a sulphate or chloride of other material may be
added to the depolarizing compound in the process of compression as a binding
material, but all such means only lessen the electrical properties of the compound
proper, establish local action and reduce the high oxide to a low oxide.
After experimenting with different materials I have found a simple solution
of the question in the dipping of the element in a plastic mixture of plaster of
paris and water, thereby providing the whole, with an outer and thin envelope of
plaster of paris or gypsum, and repeated experiments have convinced me that such
envelope is a necessity, if the negative element consists of a conductor having com-
pressed thereon a high oxide of lead, brought to its high state of oxidation by the
aid of an electric current independent of its conductor. It should be clearly under-
stood that the outer envelope only fulfils the office of a non-conducting cement
keeping mechanically together the different parts out of which the negative element
consists.
This outer envelope is also beneficial for the reason, that the depolarizing com-
pound, being of an unstable nature, if accidentally coming in contact with some
salts of other materials, such as chloride of ammonia or other chlorides or bromides
or nitrates, may lose a great part of its oxygen and therefore usefulness.
Both of the elements are preferably secured to the cover or cap in the following
manner: The upper parts of the rods are screw-threaded. A nut is placed on
the lower end of the thread and the upper part of the rod carried through the hole
with which the cover is provided, the rod is secured to the cover with the aid of a
second nut and washer so as to provide effectually against any leakage or creeping
of salt.
It is well understood that wires from the outside circuit can be secured with or
without the aid of additional nuts to the upper parts of the rods.
I have found it advantageous to cover the first mentioned nut and in fact the
whole inner part of the top of the cover with cement.
In the drawing the nuts of the positive element are designated by the letters d;
d³ is a washer which is interposed between the upper nut and cover B: 6 is the
screw-threaded portion of the rod D. The nuts of the negative element are desig-
nated by the letter d¹, and d³ is a washer likewise interposed between the upper
nut and the cover B; b is the screw-threaded portion of the rod d³. The negative
element may also be provided with the rubber rings e.
As an electrolyte I use dilute sulphuric acid, designated in the drawing by C.
I have described the method of producing the positive element as pouring the
metal into a containing cup, but a second and very efficient method may be
substituted. The metal may be cast into suitable moulds and when cold plunged
into a hot solution of cement, thereby providing the metal with an outer non-
conducting layer, which for all practical purposes may be called a cup. It is
understood that the upper surface should be cleaned from the cement. In my
experiments I have found that about six parts of burgundy pitch, two parts of
shellac, one part of gutta percha and a very small proportion of wax melted together

page_text: will answer the purpose best. Wherever therefore in this specification or claims
following the same the word cup or containing cup is mentioned, I include under
it the cup first spoken of as well as the cement cup.
I have described the jars as screw-threaded but the same need not necessarily
be the case, as a different arrangement be substituted for the screws as shewn in 5
the drawing, so also may the shape of the positive or negative or both elements
be altered without departing from the scope of my invention.
As to the density of the electrolyte,, the same may vary, but one ounce of
commercial sulphuric acid to eight ounces of water worked in practice best.
Extensive experiments have also proved that pyritic acid is not well adapted 1
for the electrolyte, where the positive element consists of zinc or a zinc amalgam.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
say is: -
1st. A positive element consisting of a containing cup of a material designed 1
to remain inert, a conducting rod passing into said cup and a solid body of an
alloy of mercury and a metal, as zinc, substantially integral with said cup and rod,
the surface of said solid body being designed to be acted upon by the electrolyte
when the cell is working.
2nd. A positive element for primary cells consisting of the compound F¹, the 2
containing vessel F, the conductor D¹.
3rd. The method of producing a positive element for primary batteries which
consists in first providing a containing vessel with a metallic rod, then filling said
containing vessel with a compound in its molten state, said compound being
designed to generate by chemical interchange with the electrolyte, currents of
electricity, and lastly providing the bottom or lower part of said containing vessel
with a cement.
4th. A negative electrode for primary cells consisting of a metallic rod sur-
rounded as to all its parts designed to be immersed in the electrolyte, with a high
oxide of lead, said high oxide of lead being surrounded or enveloped by a cement
such as plaster of paris.
5th. The method of preparing a negative element for primary cells which consists
in; firstly, bringing a low oxide of lead to a higher state of oxidation through the
action of an electric current; secondly in compressing the powdered high oxide
of lead around a metallic rod and thirdly, providing the whole with an outer layer
of a cement such as plaster of Paris.
6th. I. primary cells a negative element consisting of a metallic rod having
compressed thereon and being embeded in a high oxide of lead, said high oxide of
lead having been brought to its high state of oxidation by the aid of an electric
current.
7th. A positive element consisting of a containing cup of a material designed to
remain inert, a conducting rod passing through the cup and a solid body of an alloy
of mercury and a metal, as zinc, filling the space between said cup and rod, the
surface of said solid body only being exposed.
8th. An improved primary cell consisting of a vessel containing dilute sulphuric
acid as an electrolyte, a positive element consisting of a containing cup, a con-
ducting rod and a solid body of an alloy of zinc and mercury cast between said cup
and rod, a negative element having compressed thereon a high oxide of lead, both
the positive as well as the negative element being suspended from the cap or cover
of the containing vessel.
9th. An improved primary cell consisting of a vessel containing dilute sulphuric
acid as an electrolyte, a positive element and a negative element, said negative
element consisting of a conducting rod having compressed thereon a high oxide of
lead held together by an outside layer of cement.
10th. A negative element for primary cells consisting of a metallic rod sur-

page_text: rounded as to all its parts designed to be immersed in the electrolyte, with a high
oxide of lead, said high oxide of lead being surrounded or enveloped by plaster of
paris.
Dated this 15th dox of Tune 1807
HASELTINE. LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.