Improvements in Secondary Batteries.
Year: 1897

page_text: Date of Application, 27th Apr., 1897-Accepted, 23rd Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Secondary Batteries.
I, CHARLES EUGENE LEE, 76-82 West Jackson Street, in the City of Chicago,
County of Cook and State of Illinois, United States of America, Manufacturer,
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 storage batteries and has for its object to provide certain
new and useful improvements in storage batteries, more particularly set out
hereinafter.
I will first describe somewhat fully the construction of a battery which contains
my invention, and will then more fully indicate some of the advantages and dis
tinguishing peculiarities of the same. This particular form of my invention is
illustrated in the accompanying drawings, wherein Figure 1 is a vertical section;
Figure is a horizontal section on the line 2-2 of Figure 1; and Figure 3 is a
view of the negative electrode. Like parts are indicated by the same letter in all
the figures.
The
A is the exterior cup or case of the cell. B is the negative element thereof,
consisting primarily of a gauze-like cylinder, from which leads the conductor C
to the terminal D. E is an interior porous cup, case, or the like, preferably
sealed by caps F G. This porous cup and the outer gauze cylinder are kept in
proper relation by the cushion rings H. Within the porous cup there is first.
a mass of active material J, and then an inner metallic part K, preferably circular
in cross section and also preferably tubular. This terminates in the upper end L
which leads to the terminal M. The active material J is composed of an oxida
of the metal of which K is made & which may, for example, be lead.
electrolyte, of course, is introduced between the porous cup and the outer cup or
case. For this electrolyte I have used a solution of sulphate of cadmium having
a sp. grav. of 27° to 30° B. This, as described, constitutes a complete battery,
one in which my invention is made use of. As previously suggested, however.
I do not wish to be limited to this particular form or precise relation of parts
or to this particular electrolyte. All that I have described up to the present
time is but an example, so to speak, of my invention; and, of course, some of
these features and elements can be retained in my invention while others are
dispensed with
I will now proceed to a more detailed examination of the several features of
my battery, illustrating and explaining the several objects to be attained and
referring to the difficulties obriated by my invention.
Referring to the positive electrode, the inner metallic part L is as stated pre-
ferably circular in cross-section, the principal point being that it should present
a continuous exterior surface, as distinguished from a surface broken up by sharp
edges or points. This metallic part, if having such broken surface, is found by
experience to be speedily oxidised, and thus the operation of the battery is greatly
limited and interfered with. If this metallic part be made approximately cir-

page_text: cular, it is best to make it tubular, as a less amount of metal and hence a less
weight is used. Another advantage flowing from this form of construction of
the metal is that the active material of whatever kind or description may be
arranged for a uniform layer about this centre lead or metal. Thus if the porous
cup E be also circular in cross section the active material will be enclosed between
circular walls and will assume the form of an annulus, as indicated in Figure 2,
hence the current in every direction passes through an equal amount of the active
material and passes wholly through the active material, so as to produce a high
efficiency and uniform action. This cup so shaped is preferably sealed at each
end by caps F and G, preferably of insulating material, so that the current has
no tendency to pass therethrough, but only passes through the porous cup and
the active material to the lead. Of course the porous cup may have substituted
for it any sort of suitable support or containing device, but I prefer the porous
cup.
The negative element comprises preferably a wire cloth. Of course instead of
a wire cloth a similar arrangement, as for example, a series of interwoven rods
could be used, but in practice I employ copper wire cloth and to it attach the
conductor which leads to the terminal. This wire cloth is dipped in mercury or
subjected to a mercury treatment so as to have formed on its wires a mercury
coating. Now in the attempt to apply mercury to flat surfaces, it is found that
the mercury gets out and escapes; that is to say, if mercury be applied to the flat
surface of a plate, as the surface of the negative element in a storage battery,
the mercury will gradually escape from the metal of the plate and drip down.
With a wire cloth or gauze this tendency is obviated. The mercury has an
extended surface on which to adhere and is also held in position at the numerous
points at which the wires overlap each other. The electrolyte which I employ
is a neutral state, and, of course, there are many which could be employed. 1
use sulphate of cadmium as an example.
When these parts are all suitably assembled in the complete storage battery,
the current is applied and the metallic cadmium is produced and deposited on the
negative element evenly. It would commonly be deposited as a mere surface
deposition. In this operation sulphuric acid is produced, but not in sufficient
quantities to continue local action when the circuit is open. In the action of
discharging the battery, the above process is reversed, the metallic cadmium
produced and deposited on the mercury-covered gauze and re-combined with the
electrolyte, and the free sulphuric acid disappears. When the circuit is left
open, the quantity of free sulphuric acid is insufficient to effect a re-combination
with the metallic cadmium and therefore little, if any, so-called local action
takes place. As previously stated my electrolyte consists of a neutral salt without
any associated' acid.
It is understood that there must be a sufficient and suitable quantity of mercury
for a negative element, and that this mercury must be evenly distributed, other-
wise there will be an insufficient and imperfect amalgamation and local action
will result when the circuit is open. The caps F and G and the ring H may be
of hard rubber.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1. A storage battery comprising an outer retaining case or cup, an outer
cylindrically shaped gauzelike body constituting the negative element, an inner
cylindrical porous cup, a central cylindrical positive element having a smooth
unbroken surface, a mass of active material annular in cross-section interposed
between the walls of the porous cup and the surface of the opposite element, the
two elements and the active material arranged symmetrically about a common
axis, and a suitable fluid in the retaining cup.

page_text: 2. A storage battery comprising an outer retaining case or cup, an outer
cylindrically shaped mercury-covered copper gauze-like body constituting the
negative element, an inner cylindrical porous cup, a central cylindrical positive
element having a smooth unbroken surface, a mass of active material annular in
cross-section interposed between the walls of the porous cup and the surface of
the opposite element, the two elements and the active material arranged sym-
metrically about a common axis and a suitable fluid in the retaining cup.
3. A storage battery comprising a central positive element, a porous cup sur-
rounding the same, a mass of active material within the cup and about the
element, an outer copper gauze mercury-covered negative element, a case or cup
to contain the whole, and a suitable fluid within the same.
4. A porous battery comprising a central metallic positive element, a porous cup
surrounding the same, a mass of active material within the cup and about the
element, an outer copper gauze mercury-covered negative element, an insulation
seal at each end of the porous cup, a case or cup to contain the whole, and a
suitable fluid within the same.
pated this with day or apim
F. WISE HOWORTH,
46, Lincoln's Inn Field's, London, W.C., Agent for the Applicant.