Year: 1888

page_text: Date of Application, 17th Jan., 1888
Complete Specification Left, 8th Sept., 1888
Complete Specification Accepted, 12th Oct., 1888
1, DAVID URQUHART of 4 The Sanctuary in the City of Westminster Electrical
Engineer do hereby declare the nature of this Invention to be as follows:-
My Invention relates to batterics for producing electricity and is applicable both to
primary and secondary batteries. It has for its object to provide elements consisting
wholly or principally of peroxide of lead having a durable and hard character and
relates also to the procuring of a good and durable electrical contact and attachment
for the conductors to and from the elements all as hereinafter described.
According to my Invention I treat the peroxide of lead with a compound or
material which will cause a setting of the peroxide into a hard and durable mass.
The elements made according to my Invention are for use as the positive elements
in the battery and are much lighter than the ordinary plates now in use and do not
contain any metal which can form injurious local currents in the elements.
.
In carrying out my Invention I take peroxide of lead which may be made in any
suitable way either chemically or by heat or by electrolysis but care should be taken
that it contains no metallic lead. This peroxide I moisten with a solution (preferably
a ten per cent. solution) of Ammonia and I mix or grind the whole into a paste and
then I press it into plates or to the required form for the elements such for example
as into rods tubes or in fact any other shape that may he required-I allow the shapes
to stand for some days and then I soak them in an alkaline solution of oxide of lead
and I again allow them to stand repeating the process as many times as may be
necessary. In this manner I produce hard and resisting elements of peroxide of
lead which can be used as the positive plates of a battery with suitable opposite
elements and electrolyte such as either analgamated zinc or spongy metallic lead as
the negative elements and dilute sulphuric Acid as the electrolyte. These positive
elements when exhausted may be recharged by means of an electric current and they
will bear without disintegration a much larger current than ordinary battery plates
will bear so that the time required to charge them is much shorter than the time of
discharge.

page_text: Or I may make the elements by adding a small proportion of sulphide or sulphite
of lead to the peroxide in mixing preferably about five per cent of sulphide or
fifteen per cent. if sulphite. These I then treat as hereinbefore described-When
using sulphide I prefer to dry the elements after pressing with artificial heat before
applying the alkaline solution as described-I may mix the peroxide or the peroxide
and sulphide or sulphite with water only treating the elements with ammonia after
they are well dried and before applying the alkaline solution of oxide of lead as
hereinbefore described. Or I may use a weak solution of sulphurous acid to moisten
the peroxide. In this case care must be taken to have only sufficient sulphurous acid
present to convert about fifteen per cent. of the peroxide into sulphate so as to produce
the required setting action without impairing the efficiency of the plate as a depolarizer-
Or I may make the elements by mixing sulphite of lead with both peroxide and oxide
of lead the proportions I prefer being respectively 1 part of sulphite of lead 4 parts
of peroxide of lead and 2 parts of oxide of lead but in this case the element must be
charged by an electric current before it can be used in a battery.
I may use asbestos fibres in making the element so as to give the element more
strength and hold it together in case it should be cracked by rough usage.
Contact may be made with the clements in any convenient manner such as by a
clip over the top of the element the surface of the clip being coated with platinum to
prevent its being attacked by the acid or the element may be pressed by means of a
vulcanite or other similar spring against a strip of platinum attached to the side of the
containing box.
Or when the peroxide is formed into a hollow rod the centre hole may be fitted
with a band of India rubber of a slightly larger diameter than the hole in the rod so
that the India rubber has to be stretched to insert it. A strip of platinum foil is
inserted between the rubber and the inside of the element so that when the tension is
removed from the rubber it expands inside the hollow rod and presses the platinum
firmly but elastically against the peroxide.
When the peroxide is formed into a large tube with comparatively thin walls the
contact may be made by encircling it with a strong indiarubber or other elastic band
between which and the peroxide the platinum is inserted.
Platinum wire may also be inserted in the element when it is being made but care
must be taken not to connect this wire to the charging current.
Dated this 17th do of 1000
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London.

page_text: DI MUITIVATION.
Improvements in Electric Batteries and Elements therefor.
1 DAVID URQUHART of 4 The Sanctuary in the City of Westminster Electrical
Engineer 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 that is to say :-
My Invention relates to Batteries for producing electricity and is applicable both
to primary and secondary batteries. It has for its object to provide elements con-
sisting wholly or principally of peroxide of lead having a durable and hard character
and relates also to the procuring of a good and durable electrical contact and attach-
ment for the Conductors to and from the elements all as hereinafter described.
I am aware that the use of peroxide of lead for producing plates or elements to
constitute the anodes (in charging) of a secondary battery or negative elements in a
primary battery has been proposed but it has been found that the plates or elements of
peroxide of lead made as hitherto proposed quickly disentegrate and fall to pieces
when immersed in a liquid such as dilute Sulphuric Acid.
To overcome this objection I according to my Invention treat peroxide of lead
(preferably that obtained by electrolysis) with a compound or material which will
cause a setting of the Peroxide of lead into a hard and durable mass. Such compound
or material in most cases is or contains a reducing or deoxidizing agent that is an
agent which produces a chemical change in the mass of peroxide but by reducing
only a portion of the said peroxide to a lower degree of oxidation. In this case it is
necessary that the reducing action should be gradual otherwise the heat generated
may disintegrate the mass of Peroxide. It is preferable that the reducing action
should extend over many hours or even days but I may also produce or improve the
setting and hardening of the peroxide of lead by the use of a compound or material
such as an Alkaline solution of Plumbic Oxide which does not reduce the original
quantity of peroxide to a lower degree of Oxidation but which causes the Peroxide
gradually to enter into combination with another body in this case the monoxide of
lead.
I have made many experiments by mixing peroxide of lead with Saccharine or
starchy matter with Sulphur or with metallic Sulphides. I have not however been able
to obtain a wholly satisfactory result with any of these reducing agents most of which
may be said to act too slowly at ordinary temperatures and too rapidly when the
mixture is raised to a comparatively high temperature. Many other reducing
Agents have been tried with only partial success. Sulphurous and Hydrochloric acids
I have found to be too rapid in their action. The reducing Agents with which I have
obtained the most satisfactory results are ammonia or its sesquicarbonate, various
Sulphites amongst which I prefer to use the Sulphite of Lead, and also the alkaline
sulphides.
In one mode of carrying out my Invention I moisten Peroxide of Lead in the
condition of powder with a ten per cent. solution of ammonia and I rapidly mix the

page_text: whole into a paste which I press or mould into any required form such as that
of a plate rod or tube. I allow the moulded masses to stand for two or three days
in a warm atmosphere and when they have become dry and hard I prefer to again
moisten them with a solution of Ammonia or to expose them to the action of Ammonia
gas in a close chamber after which the drying process is repeated. The masses will
not now disintegrate when immersed in water or dilute sulphuric acid. But to increase
their density and hardness I prefer to soak them in an Alkaline solution of Plumbic
Oxide which may be conveniently made by boiling Oxide of lead in a twenty or thirty
per cent. solution of Caustic Potash or Soda until the solution becomes saturated with
the Oxide. After this soaking operation (which may be repeated until any required
degree of density is obtained) the moulded masses are exposed to the atmosphere
for two or three days or for a few hours to a current of warm air containing Carbonic
acid which may be conveniently produced by the combustion of charcoal or coke.
The masses are then immersed in water to extract the (partly Carbonated) Alkali and
finally they are immersed in dilute Sulphuric acid and dried by exposure to a warm
atmosphere. The elements thus produced when fitted with a suitable contact-piece
such as a binding clamp protected from the action of the acid electrolyte by means of
platinum foil, may be used as the positive pole plates of a battery either primary or
secondary. In the former case the opposite element may be amalgamated zinc and in
the latter case it may be spongy lead. In both cases the electrolyte may be dilute
sulphuric acid.
Another mode of carrying out my Invention is to mix peroxide of lead with
Sulphite of lead in or about the proportion of one part by weight of the Sulphite to
at least two parts by weight of the peroxide. The intimate mixture of these ingredients
is made into a paste with water and then pressed or moulded into any required form.
Or in the case of flat plates the mixture may be moulded in a dry state and whilst
still in the moulds (consisting of a very shallow box from which the top is removed)
subjected to the action of moisture in a steam chamber. The plates can be prevented
from adhering to the mould by the interposition between the two of a linen or other
fabric. They may generally be handled almost immediately after the moulding process.
The plates when manufactured are stood on edge to dry in a warm atmosphere for at
least three or four days a period which may with advantage be considerably increased.
They are afterwards immersed for a few seconds in very dilute Sulphuric acid (say
one part by weight of acid to 20 parts or more by weight of water) and again put
aside to dry. I subsequently treat them by immersion in an alkaline solution of
oxide of lead as herein before mentioned. I have found that the addition to the mixture
of a small proportion of magnesia somewhat improves the structure of the resulting
product. The exact proportions of the ingredients which have been adopted in practice
are as follows:

page_text: charging tank may be plates of Carbon or more advantageously, plates of any
suitable lead compound to be reduced to the condition of spongy lead. The elements
manufactured according to the process hereinbefore described may also be similarly
charged prior to use as their capacity is thereby improved.
Another process consists in treating peroxide of lead with an alkaline sulphide such
as potassic pentasulphide (K, S,) which may either be intimately mixed with the
peroxide in a dry state and be subsequently moistened, or may be employed in
solution to form a pasty mass with the peroxide. Or a portion of the sulphide may
be mixed with the peroxide in the solid state, and the mixture (preferably contained
in a mould) may be subsequently moistened with a solution of the sulphide. Thus for
example I make peroxide of lead into a paste with a 50 per cent. solution of potassic
sulphide and immediately mould this mixture into elements of the required form.
Or I place within a frame or mould a dry mixture of
afterwards moistening the mixture with a 30 per cent. solution of the sulphide. Plates
or elements thus made may, after drying, be treated with an alkaline solution of
plumbic oxide as hereinbefore described.
For the purpose of obtaining contact with the elements when they are used in a
primary or secondary battery platinum wires may be inserted in them during the
process of manufacture the parts of such wire which are inserted in the elements
being preferably flattened by being passed between rollers. These wire contacts
should not however be used in the process of charging the elements in the first
instance as the evolution of Oxygen from them tends to disintegrate the substance of
the elements. In charging I prefer to establish contact with the elements by means of
ebonite clips passing over the top of the elements; the inner extremities of the said
clips carrying pieces of platinum foil which come into contact with the element and
which are also in contact with a platinum wire connected to a small binding screw at
the top of the clip. The contact made by the said clips should be shifted once or
twice during the process of charging.
In the case of tubular elements I may adopt the following mode of establishing
contacts. I take an India rubber tube of an outside diameter somewhat larger than
the inner diameter of the tubular element and I pass through the latter a cord attached
to one end of the India rubber tube. By stretching this tube it can readily be drawn
into the interior of the element. A strip of platinum foil attached to a wire of the
same metal is now inserted between the rubber and the inside of the element. When
the tension is now removed from the rubber it expands inside the hollow of the
element and presses the Platinum tightly against the interior surface thereof.
When the element is in the form of a hollow Cylinder of an internal diameter much
larger than the thickness of the material, contact may be made by encircling one end
of the Cylinder with a strong india rubber band between which and the peroxide
surface a platinum contact piece is inserted it being connected to a platinumi wire as
before.
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 :-
First In or for electric batteries the manufacture from peroxide of lead of plates
or elements by bringing the peroxide into intimate contact by means of an acqueous
fluid or solution with ammonia or equivalent reducing agent which will produce a slow
chemical change in the peroxide whereby it is caused to "set" and thus becomes a
permanently coherent mass substantially as hereinbefore described.
Second-In or for electric batteries treating the plates or elements formed of
peroxide of lead and produced as hereinbefore described with a solution of Oxide

page_text: of lead in Caustic Alkali substantially as and for the purpose hereinbefore
described.
Third-The manufacture of plates or elements for electric batteries by treating
peroxide of lead with ammonia or with the solution of an alkaline sulphide and
subsequently with an alkaline solution substantially as herein before described.
Fourth: The manufacture of plates or elements for electric batteries by combining
peroxide of lead or both peroxide of lead and monoxide of lead with Sulphide or
Sulphite of lead with or without the addition of magnesia substantially as herein-
before described.
Fifth In or for electric batteries the means for making contact between the
elements and the conductors consisting of an elastic fitting piece pressing platinum foil
in contact with the interior of the element the said platinum foil being connected to
the Conductors substantially as herein before described.
71 3 of Santambon 1888