Improvements in the Manufacture of Electrical Conductors and Electrodes, and for connecting them, and for analogous purposes.
Year: 1890

page_text: Date of Application, 6.h Nov., 1890
Complete Specification Left, 5th Aug., 1891-Accepted. 241, Oct.
1.91
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Electrical Conductors and
Electrodes, and for connecting them, and for analogous
purposes.
I, JULIUS MARX of Sachsenhausen, Frankfort-on-Maine in the Empire of
Germany, Chemist, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the manufacture of electrodes or plates for galvanic
battery cells and other electrical apparatus in which a semi-conductor is required
and to improved means for combining metallic and semi-conductors.
Electrodes for primary or secondary battery plates and the like have heretofore
been manufactured by preparing compositions containing carbon or carbonaceous
matter and subjecting them to intense heat or calcination. This method of manu-
facture renders it almost impossible to attach in a reliable manner the metallic
conductors or strips or to make the connections in the preliminary moulding or shaping
process when the materials are in a plastic condition as the metals usually employed
for forming the said conductors would be melted at the temperature to which the
article is subsequently exposed.
According to my invention the heating or baking process heretofore employed in
the manufacture of semi-conductors such as carbon plates for electrodes and the
like is dispensed with, the carbonaceous or other equivalent material; being
combined with a suitable binding agent and moulded to the required shape as
hereinafter explained.
The binding agent used to cement the materials employed in the manufacture of
electrodes or semi-conductors according to my invention may consist of a suitable
non-conducting or other cement or substance capable of producing the requisite
coherence (excluding however sulphur and sometimes joiner's glue and the like).
These substances or cements may be of such a nature as to simply require mixing
with the other ingredients, being capable of subsequently setting or hardening or
they may be such as to require melting or softening by heat in order to enable
them to be mixed or combined with the other ingredient or ingredients of the
composition.
When the composition is employed for connecting an ordinary carbon electrode
with the metallic conductor it is more expedient to employ melting or fusible
cements or binding agents in the preparation of the composition which is thereby
rendered nonhygroscopic.
In order to manufacture an electrode suitable for example to a Leclanché battery
the process according to my invention may be conducted as follows:-Pulverized
graphite, retort carbon or coke is mixed with melted paraffin wax or other wax, mastic,
esin, stearine and the like or with a mixture of these substances. The paraffin or
he like is preferably used in such a quantity as to suffice to render the mixture
plastic or capable of being conveniently moulded. This paste is placed in a mould
preferably of the form corresponding to that of the finished electrode but the electrode
may be cut to size and shape afterwards if preferred. It is advantageous to introduce
nto the mould a wire or strip or wires or strips of metal or wire net-work or the
ike which are or is utilized for making the connections being partially embedded
n the substance of the electrode. This same or a similar mixture may also be
mployed as a cement for connecting any non-metallic electrode with a metallic
onductor or wire. In this case the carbon or other electrode is placed in a mould
r in a frame so arranged as to form a vacant space between the sides of the mould

page_text: The plastic or pasty
space and on cooling
The conducting wire
and the electrode on one side or on more than one side.
mass preferably under pressure is then introduced into this
adheres to the electrode so as to form one solid block.
inay be attached in any suitable way for instance the wire or other conductor is
inserted in the plastic or pasty mass keeping an end or ends projecting or the
materials are allowed to cool and set and the conductor being placed in contact
therewith hot composition is put over the wire and becomes firmly welded or united
with the other part thus forming an effectual connection.
Large carbon electrodes of such dimensions that it is not convenient to form
them in one piece may be constructed by taking a number of blocks or plates of
any convenient size and placing them side by side so as to form say one half or side
of the electrode. These plates are then coated on one side with a layer of a
composition consisting of pulverized graphite for example mixed with melted
paraffin or other like cementing materials and woven wires or other conductors are
laid on this coating and coated over with the same composition. The remaining
plates are then placed upon the top so as to form the other side or half of the
electrode. The plates may be heated before applying them to the cement or
composition or they may be first placed in position the whole of the electrode being
afterwards heated sufficiently to cause the cement or composition to adhere.
ordinary soldering lamp or other suitable heating device may be employed to heat
the composition when it is used for making joints and the like.
An
Electrodes may also be constructed according to my invention with carbon rods
such as are employed in are lamps, these rods being placed side by side in any
desired number and comcuted together by coating one or both ends with a
composition consisting of graphite and paraffin for example. Electrodes thus
constructed present a large area of acting surface in a relatively small space and
the joints or crevices between the rods may be filled up if desired with the cementing
material.
Electrodes manufactured according to my invention whether composed entirely
of the compositions hereinbefore described or of combinations of the said composition
with plates or pieces of carbon or other ordinary materials (such as for instance
graphite) can be employed for electric or electrolytic purposes generally. They
may be employed under suitable conditions for generating chlorine and in certain
cases when strong currents are employed or great chemical resistance is required for
example enamels composed of a readily fusible mixture of alkaline borates alkaline
silicates and fluor-spar for example may be substituted for the paraffin or preferably
moist or plastic cements are employed in place of fusible cements being afterwards
coated or impregnated entirely or partially with a fusible cement.
When other than fusible cements are employed and when at the same time the
semi conducting mass is employed simply for connecting the electrode with the
conductor being out of contact with liquids or moisture a composition consisting of
ordinary Portland or Roman cement mixed with graphite may be employed but it
is important to obtain intimate contact between the particles by applying pressure
or beating or ramming in the mass in order to render it sufficiently conductive.
When this composition is intended to be used in contact with water or liquids it
is advantageous to add a weak solution of water-glass, or alkaline silicate in mixing
the ingredients and also prefer to repeatedly saturate the composition with the
same.
In place of the Portland cement or flux composed of pulverized alkaline silicate
and fluor-spar may be employed. Compositions composed of glycerine and white
or red lead or equivalent metallic compound may also be employed with advantage
as a binding agent in combination with graphite or other carbon. These com-
positions also are preferably subjected to pressure or ramming.
The compositions that do not require melting or softening by heat have the
advantage of enabling the work to be performed without heating the materials and
more readily fill large moulds.
Instead of forming the electrodes by the aid of moulds they may be made by

page_text: hand or by surrounding or covering a wire strip or the like with the plastic com-
position and repeating this operation till the desired shape and size are obtained..
Dated this 6th day of November 1890.
J. H. JOHNSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Electrical Conductors and
Electrodes, and for connecting them, and for analogous
purposes.
I JULIUS MARX of Sachsenhausen, Frankfort-on-Main, in the Empire of
Germany Chemist, 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 the manufacture of electrodes, or plates, for galvanic
battery cells, and other electrical apparatus, in which a semi-conductor is required,
and to improved means for combining metallic and semi-conductors.
Electrodes for primary, or secondary, battery plates, and the like, have hereto-
fore been manufactured either by preparing compositions containing carbon, or
carbonaceous matter, and subjecting them to intense heat, or calcination, or by con-
glomerating them by means of glue, albumen, sulphur, or sulphides, mixed with a
conductive powder, or by mixing india rubber with coarse carbon. The calcining
method of manufacture renders it almost impossible to attach, in a reliable manner,
the metallic conductors, or strips, or to make the connections in the preliminary
moulding, or shaping, process, when the materials are in a plastic condition. as the
metals usually employed for forming the said conductors would be melted at the
temperature to which the article is subsequently exposed. The conglomerating
methods hitherto used have otherwise not proved successful the glue, albumen,
sulphur, or sulphides, employed being rapidly destroyed by the reactions going on.
In other cases where the conductive material was in the form of a very coarse
powder, very imperfect electrodes resulted.
According to my invention the intense heating, or baking, process heretofore
employed in the manufacture of semi-conductors, such as carbon plates for electrodes
and the like, is dispensed with, the carbonaceous, or other equivalent conductive,
material being combined with a suitable binding agent and moulded to the required
shape as hereinafter explained. But this is effected by binding agents other than
glue, albumen, sulphur, sulphides, and such like, which are too readily dissolved, or
destroyed, by the reactions going on likewise the powder need not be coarse as is
the case when india-rubber is employed as hitherto; on the contrary fine powder is
preferable, provided the new conductors are made dense enough, which is easily
attained by ramming, pressing, or the like operation. As a rule I prefer to have
recourse to considerable pressure for the purpose.
The binding agent, used to cement the materials employed in the manufacture of
electrodes, or semi-conductors, according to my invention, may consist of a suitable
non-conducting, or other, cement, or substance, capable of producing the requisite
coherence, (excluding however sulphur, sulphides, common joiners' glue, albumen,
caseine and similar easily attacked bodies). The substances, or cements, to be
employed may be of such a nature as to simply require mixing with the other
ngredients, being capable of subsequently setting, or hardening; or they may be
such as can be melted, or softened, by moderate heat in order to enable them to
become mixed, or combined, with the other ingredient, or ingredients, of the
composition.
When the composition is employed for connecting an ordinary carbon electrode
with a metallic conductor it is more expedient to employ, in the preparation of

page_text: the composition, cements, or binding agents, which can be melted, or softened,
by moderate heating, as the composition is thereby rendered non-hygroscopic.
In order to manufacture an electrode, suitable for example to a Leclanché
battery, the process, according to my invention, may be conducted as follows:
Pulverised graphite, retort carbon, or coke, is mixed with melted paraffin wax, or
other wax, mastic, stearine, colophony, copal, or other resin, and the like, or with a
mixture of these substances, or, for high temperatures, readily melting enamels
may be used. The paraffin wax, or the like, is preferably used only in such a
quantity as to suffice to render the mixture plastic, or capable of being conveniently
moulded. This paste is placed in a mould, preferably of the form corresponding to
that of the finished electrode, but the electrode may be cut to size and shape after-
wards, if preferred. It is advantageous to introduce into the mould, a wire, or
strip, or wires, or strips, of metal, or wire net-work, or the like, which are, or is,
utilized for making the connections, these metallic parts being partially embedded
in the substance of the electrode.
This same, or a similar, mixture may also be employed as a cement for connecting
any non-metallic electrode with a metallic conductor or wire. In this case the
carbon, or other, electrode is placed in a mould, or in a frame, so arranged as to
leave a vacant space between the sides of the mould and the electrode on one side,
or on more than one side. The plastic, or pasty, mass, preferably under pressure,
is then introduced into this space and, on cooling, adheres to the electrode so
as to form one solid block. The conductor, or wire, may be attached in any
suitable way; for instance, the wire, or other conductor, may be inserted in
the plastic, or pasty, mass keeping an end, or ends, projecting; or the materials
are allowed to cool and set and the conductor, or wire, being placed in
contact therewith, hot composition is put over the conductor, or wire, and
becomes firmly welded, or united, with the other part, thus forming an effectual
connection.
For joining carbon to carbon the new compositions can be employed with great
advantage (as they admit of the employment of liquids) to build large carbon
electrodes of such dimensions as are not conveniently formed in one piece. Such
electrodes may be constructed by taking for instance carbon rods, or a number of
blocks, or plates, of any convenient size, and placing them side by side so as to
form say one half side, or thickness of the electrode. These plates are then coated
on one side with a layer of a composition consisting of pulverized graphite, for
example, mixed with melted paraffin wax, or other like cementing material, and
woven wires, or other conductors, are laid on this coating and coated over with the
same composition as hereinbefore described. The remaining plates are then placed
upon the top so as to form the other half side, or thickness, of the electrode. The
plates may be heated before applying them to the cement, or composition; or they
niay be first placed in position, or the whole of the electrode may be afterwards
heated sufficiently to cause the cement, or composition, to adhere, pressure being
preferably employed. An ordinary soldering lamp, or other suitable heating device,
may be employed to heat the composition when it is used for making joints and the
like. As mentioned electrodes may also be constructed according to my invention
with carbon rods such as are employed in are lamps. These rods may be taken
instead of or together with blocks and plates of carbon. They are placed side by
side, in any desired number, and cemented together by coating one or both ends
with a composition such as is herein before described, consisting of graphite and
paraffin wax for example. Electrodes thus constructed present a large area of
acting surface in a relatively small space. The joints, or crevices, between the rods
may be filled up, if desired, with the cementing material.
Electrodes manufactured according to my invention, whether composed entirely
of the compositions herein before described, or of combinations of the said com-
positions with plates, or pieces, of carbon, or other ordinary materials, (such for
instance as graphite) can be employed for electric, or electrolytic, purposes

page_text: generally. They may be employed, under suitable conditions, for generating
chlorine.
In certain cases when currents producing heat are employed, or great chemical
resistance is required, enamels composed of a readily fusible mixture of alkaline
borates, or alkaline silicates, and fluor-spar and sulphate of barium, for example,
may be substituted for the paraffin wax or similar low fusible binding agents. Such
a mixture may be made for example by melting together 7 kg. of fluor-spar with
35 kilogrammes of waterglass and so much graphite as is sufficient to bring about
the desired degree of conductivity. Otherwise in these cases moist, or plastic,
cements may be employed the mixture being afterwards coated, or impregnated,
entirely, or partially, with a fusible substance to avoid the capillary, or sucking,
action upon liquids. In this latter case the mixture of waterglass cement and
graphite referred to at the end of this Specification will be found suitable. After
setting it is impregnated with paraffin wax, if it is desired to work at moderate
temperature, but if high temperatures are employed it may be impregnated with
any of the usual earthenware enamels.
When the semi-conducting mass employed simply for connecting the electrode
with the conductor and is not to be in contact with liquids, or moisture a simply
conglomerating composition for example one consisting of ordinary Portland, or
Roman, cement mixed with graphite, may, conveniently be employed but it is
important to obtain the necessary intimate contact between the particles by applying
pressure, or beating, or ramming to the mass, in order to render it sufficiently
conductive.
When the composition however is intended to be used in contact with water, or
other liquid, it is advantageous to add a weak solution of water-glass, or alkaline
silicate, in mixing the ingredients, and also I prefer to repeatedly impregnate the
composition with the same solution, or the mixture is impregnated finally with a
melting cement or covered with a conductor made by a melting cement such as
paraffin-wax on any easily fusible enamel for example one composed of a mixture
of say about 160 kg. of waterglass with 20 kilogrammes of fluor-spar. Some boric
acid may be substituted for part of the water-glass if preferred.
In place of the Portland cement, a flux composed such as described or one
compound of pulverized alkaline silicate and fluor spar may be employed and to
render it readily fusible oxide of lead may be added. Compositions composed of
glycerine and white, or red, lead, or equivalent metallic compound, may also be
employed, with advantage, as a binding agent in combination with graphite, or other
carbon. These compositions also are preferably subjected to pressure, or ramming.
Of this kind of compositions the following will be found to answer. I litre of
concentrated glycerine 10 kilogrammes of oxyde of lead and 20 kilogrammes of
moistened graphite powder are mixed thoroughly together and moulded quickly
before hardening.
The compositions that do not require melting, or softening, by heat have the
advantage of enabling the work to be performed without heating the materials and
more readily fill large moulds.
Instead of forming the electrodes by the aid of moulds they may be made by
hand, or by surrounding, or covering, a wire strip, or the like, with the plastic
composition and repeating this operation till the desired shape, and size, are
obtained. A further way of obtaining a reliable contact between the metallic
conductor and the conductive mixture is to cover a metallic net for example with
the mixture and then to roll the net so covered, and then the outside should be
carefully covered with the mixture to prevent the metal being destroyed.
I have herein before used the expression "semi-conductor" to signify that the
conductivity of the aforesaid artificial conductors is much less than is that of
metallic conductors but I do not mean by the said expression that the conductivity
of the said artificial conductors must be bad.
I do not limit myself to precise proportions of the ingredients which I employ,
as before stated, as the proportions necessarily depend upon the ingredients used

page_text: and entirely upon their quality, but the following have given good results, and I
give them as examples. Generally, but not always, Ceylon graphite requires
more paraffin than does retort carbon.
If Ceylon graphite be used I may take from 34 to 44 parts (the parts are by
weight) of paraffin wax to each 100 parts of the graphite but if I use retort carbon
then I may take from 26 to 34 parts of paraffin wax to each 100 parts of the said
carbon. In using cement the quantities depend greatly on the quality of cement
which varies considerably. I have obtained good results by adding from 25 to
50 parts of cement to each 100 parts of graphite, or carbon. The best cements
should be used as the conductivity diminishes as the proportion of cement employed
in the composition increases. I have also got good results with a mixture
consisting of 300 kilogrammes of cement and 500 kilogrammes of graphite and
250 litres of a solution of water-glass of 11 per cent. The pressure employed to
compress the compositions may also vary considerably. With the last named
mixture I have obtained good results by using as much as, or more than,
7000 pounds pressure per square inch. As a rule the thinner the conductors are
the higher has to be the pressure, or otherwise the mass must be softer, or wetter,
if such high pressures are not available.
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. The manufacture, and production, of conductors, or electrodes, for primary,
or secondary, batteries, or the like, by moulding, or forming, into the requisite
shape, a mixture of carbonaceous, or other conductive, matter and a binding agent
(other than those hereinbefore excluded) substantially as hereinbefore described.
2. The manufacture, and production, of electric conductors, or electrodes, for
primary, or secondary, batterics, or the like, by the combination of finely pulverized
carbon, or other conductive material, with a binding agent (with the exception of
such as are hereinbefore excluded) and compressing the mixture and allowing it to
solidify, or harden, substantially as hereinbefore described.
3. The connection of non-metallic electrodes, or the like, to metallic conductors
by moulding, or forming, around, or against, them, a mixture of carbonaceous, or
other conductive, matter, and a binding agent (other than those herein before
excluded) substantially as hereinbefore described.
4. The manufacture, as herein before described, of electrodes of large dimensions
from separate blocks, or plates, of carbon.
5. The manufacture of electrodes from carbon rods, substantially as hereinbefore
described.
Dated this 5th day of Auroust 1801
J. H. JOHNSON & Co.,
Agents.