IMPROVEMENTS IN THE CONSTRUCTION OR FORMATION OF A SECONDARY BATTERY OR ACCUMULATOR OF ELECTRICITY
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Andrew Leopold Nolf at the Office
of the Commissioners of Patents on the 29th January 1883.
ANDREW LEOPOLD NOLF of Brussels in the Kingdom of Belgium, Chemist
"IMPROVEMENTS IN THE CONSTRUCTION OR FORMATION OF A SECONDARY BATTERY
OR ACCUMULATOR OF ELECTRICITY,"
My Invention consists in the construction or formation of a secondary battery or
accumulator of electricity whose accumulating properties are considerably increased
both by the nature of the liquid employed and by the special arrangement of the
electrodes.
This secondary battery I term, Sponge-accumulator, because when the battery
is formed, the electrode which is to collect the greatest possible amount of hydrogen
is in reality a sponge of metallic lead reduced galvanically, having a bright
crystalline appearance, all the pores of which may be easily and uniformly
permeated by the liquid and by the gases no matter what may be the thickness of
the layer.
.
The other electrode is formed of a layer or thickness of pure minium, or it
may be mixed either with 50 per cent in volume of spongy lead, or with 10 per
cent in volume of hard-wood charcoal coarsely pulverized. The object of mixing
either of these is to render the mass more porous, and more capable of penetration
by the liquid and by the gases, consequently rendering it a better conductor of the
electric current.
The exciting liquid I employ for my secondary battery is a solution of caustic
soda of a density of about 1.18, and consequently containing about 13 per cent
of caustic soda. The density of the solution may however be considerably
increased or decreased without inconvenience. The solution of caustic soda may
be replaced by a mixture of Sulphuric acid (10 per cent) and water.
The apparatus is of simple construction: It is composed of a rectangular
receiver 66 centimetres in length, 33 in width, and 50 in heighth. The dimensions
of the receiver may if required be increased or decreased and its shape may be
varied at will. It may be made of wood, or of sheet iron lined with vulcanized
ו 6...מF

page_text: india rubber strongly attached to the sides by means of a solution of pure india
rubber; or it may be of stoneware, glass, ebonite, lead etc.
The following is a description of the battery. It consists of a receiver in which
is a plate of lead 1/4 of a millimetre in thickness placed vertically against one of,
the narrow sides of the receiver and covering the whole of its surface.
A space
30 millimetres large is then filled with spongy lead. Next to this is a thin
diaphragm made of pipe clay, or of special fabric which is not affected by alkali or
acid and forming a vertical partition in the receiver. A space 40 millimetres
large is then filled with minium. In the middle of the minium and separating it
vertically into two parts of equal thickness or size, is a plate of lead 1/2 millimetres
thick placed parallel to the diaphragm. Another diaphragm similar to that
previously referred to is then inserted. A space of 60 millimetres is then filled
with spongy lead. In the middle of the spongy lead and separating it vertically
into two equal parts is another plate of lead 1 millimetre in thickness placed
parallel to the diaphragm.
A
Another diaphragm similar to those previously referred to is then inserted.
space of 40 millimetres is then filled with minium arranged as before. Another
diaphragm similar to those preceding is then inserted. Another space of 60
millimetres is then filled with spongy lead arranged as before. The above described
alternative order or arrangement is carried out until the receiver is filled and in
such manner that the last space shall be similar to the first, that is to say,
30 millimetres wide and also containing spongy lead.
A conductor is put in contact with all the lead plates of the spongy lead and
communicates with the negative pole of a dynamo-electric machine and another
conductor is put in contact with all the lead plates of the minium and communi-
cates with the positive pole of a dynamo electric machine The spongy lead is
easily produced galvanically by the reduction effected by hydrogen in a nascent
state on litharge in the form of flakes; so that in order to form my secondary
battery all that is required is to fill all the spaces intended to contain the spongy
lead with litharge in flakes and to pass an electric current through the mass which
has been previously moistened by the solution of caustic soda or sulphuric acid and
water it being of course necessary to put into communication all the lead plates
inserted in the litharge with the negative pole of the dynamo electric machine
A convenient manner of arranging small sized sponge-accumulators is to make
them of cylindrical shape, as follows
The receiver is made of lead thickly painted on its outside in which is an
annular space for the reception of the spongy lead.
A cylindrical diaphragm of "biscuit" porcelain (porous clay) similar to those
employed in Bunsen batteries is then inserted. Another space then intervenes for
the minium in a pure or in a mixed state.
A small cylinder of lead is then placed in the receiver. It is to be well
understood that the sizes or dimensions may be varied at will.
The reactions produced in my accumulator when in working order are very
simple When the caustic solution is used the soda in solution is decomposed, the
oxygen attaches itself to the positive electrode and the sodium to the negative
electrode ; but the sodium in the nascent state instantly decomposes the water,
the hydrogen of which is held captive on the large surface presented by the spongy
lead, and the oxygen reforms soda by combining itself with the sodium. When the
acidulated water is used the water is directly decomposed into its two elements
hydrogen and oxygen which attach themselves to their respective electrodes.