Improvements in Secondary Electric Batteries.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Secondary Electric Batteries.
I, WILHELM PETSCHEL residing at Berlin, 9 of the Mariendorferstrasse, in the
German Empire, Electrotechnician, do hereby declare the nature of this inven-
tion 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 a secondary electric battery of which the electrodes
contain as active material small pieces of very thin (about mm.) lead plate
corroded according to Plante's process by charging and discharging; the frames of
the electrodes being composed of U-shaped narrow rails of not easily oxydizing
conducting material; the corroded pieces of lead plate being placed into the
U-shaped opening of the rails so as to be in well conducting connection with each
other and with their U-shaped supports, at the same time leaving sufficient spaces
for developing, without hindrance, bubbles on their surfaces when the current is
passing through.
To obtain this result some of the little pieces of corroded lead-plate may be
taken a little longer than the free width between the U-shape of the electrode-
frames permits for simply placing them in, so that these corroded lead plate strips
which are bent over a little at their ends, may closely attach themselves to the
frame material; and in order to procure a free space between the corroded lead
plate strips, some very narrow chips of the same lead plate may be inserted
between the longer strips, and the latter heaped on each other in varying sizes
between the single long strips, so that the whole of the material between the arms
of the rails of the U-shaped electrode frames forms a very loose coacervation or
loosely cumulated mass.
The same effect may be obtained by strewing a few little pieces of carbon or
other conducting material between the lead pieces.
Another way is to provide the small pieces of corroded lead with little bruises
(say by means of the point of a nail) so that the lead pieces may touch each other
only at their bruises.
To enable my invention to be fully understood, I will describe the same by
reference to the accompanying drawing in which-
Fig. 1 is the side-view of an electrode in the battery box;
Fig. 2 is a longitudinal section through a part of a battery containing electrodes
of the arrangement shown by Fig. 1 ;
Figs. 3 and 4 are side-views of electrodes of somewhat modified construction;
and
Fig. 4 is the top-view of an electrode frame of the kind represented by Fig. 3.
In all figures corresponding main-parts are marked with equal letters of reference,
but if the arrangements of these parts are modified, the letters of reference are
provided with different indices.
a always indicates the frame of a positive electrode, and b the frame of a
negative electrode; c is the battery-box; d indicates the small pieces of corroded
lead-plate;
e the intwined insulating walls of any non-conducting material;
frepresents the holes of these insulating walls; 9 indicates insulating supports
under the single electrodes, and indicates little pieces of conducting material, the
purpose of the latter being to keep the lead plate pieces separate from each other
Bo as to enable bubbles to develop between; and i indicate conducting rods
connecting the electrodes of similar charge with each other; and pa and pb

page_text: indicate the positive and the negative poles of the battery represented by
Figures 1 and 2.
The electrode frames are best made of lead, but any other conducting and not
easily oxydizing material, for instance carbon, may be taken. The section of the
electrode frame should be arranged so as to be of great resistance against bending,
and the weight should be as small as possible. It is therefore best to choose
the I-shape, or U-shape, or double rectangular shape for the section of the frame.
If the U-shape is choosen for the section of the frame, it is advisable to use the
U-opening of this section directed towards the space between the U-shaped
curvature of the frame and to fill the space between the arms of the latter with the
corroded lead-plate strips d in such a manner that the section of the frame itself
remains free of it, as shown in the arrangement of the new battery represented by
Figures 1 and 2. In this case the agitator liquid can also freely approach the
active material (d) of the electrode from the frame-side, which is not possible with
the position of the frame section, as indicated in Fig. 3, to the active material (d');
while if the frame-section is arranged rectangular as shown in Figs. 4 and 4*,
the agitator liquid can also from all sides, without hindrance, approach the active
material d.
Before being singly charged positively or negatively, the electrodes ad or bd
are inserted between perforated insulating walls and, remaining between these,
they can then be arranged as battery in such manner that a positively charged
electrode (a) always comes to stand by the side of a negatively charged electrode (6),
thus entirely filling the battery-box (c) withe the electrodes.
In order to be able to conveniently connect the electrodes of the same charge
(ie. the positively charged ones with each other and the negatively charged ones
with each other), without fear of contact, it is advisable to cut off the electrode
frames at both ends in unequal height and then to insert them into the battery-box
in such a way that at the one side of the latter the frames of the positive electrodes
end in a higher position than the frames of the negative electrodes, while on the
other side of the battery-box, the frames of the negative electrodes end in a higher
position than the frames of the positive electrodes. On each side of the battery-
box, a conducting rod (see k and i) is then placed over the higher ends of the
electrode frames and connected with the latter by soldering, or in another suitable
manner.
One end of the last positive electrode frame and of the last negative electrode
frame can be left longer, so as to project from the battery-box (see pa, pb in
Figs. 1 & 2, also the upper ends of the electrode frames in Figs. 3 & 4); the con-
ducting-rods (k, i) connecting the shorter electrode frames of the same charge, can
then be connected to the projecting end of the last frame of this charge after being
bent over (see Fig. 2). The frame ends projecting from the battery-box, thus form
the poles of the battery to which the leading wires are joined.
Thus arranged, the whole battery-box can be covered with a lid, from which
only the two poles of the battery are projecting.
The electrodes should not stand up on the bottom of the battery-box because in
this case in time a contact may easily be caused through the falling off of small
pieces of active material. The electrode frames may therefore be placed on
insulating supports (see g & g³) which should not be lower than 25 mm.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A secondary electric battery of which the electrodes contain as active
material small pieces of very thin (about mm.) lead-plate, corroded according to
Plante's process by charging and discharging; and as electrode frames U-shaped,
narrow rails of not easily oxydizing conducting material, of which, in the U-shaped
space between the arms, the corroded pieces of lead plate are lying flat, so that
they stand in well conducting connection with each other and with their electrode

page_text: frames, yet lying so loosely on each other, that on their whole surface bubbles can
develop, without hindrance, when the current passes through, substantially as
bereintofore described and illustrated in the accompanying drawings.
2. A secondary electric battery of which the electrodes contain as active
material very thin lead plate corroded according to Plante's process, and as
electrode-frames U-shaped narrow-rails of not easily oxydizing conducting material
in the U-shaped space of which, between the arms, the corroded pieces of lead
plate are lying flat but separated by small pieces of conducting material placed
between, or by the bruises with which the corroded pieces are provided, so as to be
able to develop bubbles, without hindrance, on the whole of their surface, when the
current passes through the battery substantially as hereintofore described and
illustrated by Figs. 3 & 4 of the accompanying drawing.
3. A secondary electric battery of which the electrodes contain as active
material small pieces of very thin lead-plate and as electrode frames U-shaped
narrow rails of not easily oxydizing conducting material, the section of the rails
being I-shaped, or U-shaped, or rectangular, substantially as hereintofore described
and illustrated by the accompanying drawing.
4. A secondary electric battery of which the electrode frames end at both sides
of the battery-box, inside the same, in unequal position of height, so that the
equally charged electrode-frames may be connected to each other by means of con-
ducting-rods being placed over the same without fear of a contact occurring, and
that conducting-pieces project as poles from the battery only at two places of the
box, substantially as hereintoforé described and illustrated by the accompanying
drawing.
In testimony whereof I have hereunto set my hand in the presence of two
aubsoribing witnessAR.