The Manufacture of an Improved Active Material for the Plates or Electrodes of Electric Accumulators.
Year: 1896

page_text: Date of Application, 4th Aug., 1896
Complete Specification Left, 3rd May, 1897-Accepted, 5th June, 1897
The Manufacture of an Improved Active Material for the Plates or
Electrodes of Electric Accumulators.
1, SIEGFRIED HAMMACHER, of 32, Andreas-strasse, Berlin, in the German
Empire, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
.
This invention relates to the manufacture of active material for the plates or
electrodes of electric accumulators, wherein the lead oxides are firmly and solidly
held together by using for this purpose substances of the "pyridine"
group.
It has already been proposed to make accumulator plates, in which lead oxides
are formed into plates by means of solutions of the residues of tar-distillation in
alcohol, petroleum-ether, etc., and dipping them into dilute sulphuric acid, after
evaporation of the solvent. Here a mechanical binding or cementation only is
aimed at, this being effected by the residues of tar-distillation, which have an
undesirable effect on the conductivity of the plates.
On
It has, moreover, been proposed to mix lead oxide with butyric acid esters.
heating, saponification takes place, and in the process of "forming," hydrocarbons,
carbonic acid, carbonic oxide, etc., and much resin are formed, the latter effecting
a mechanical binding or cementing together of the particles of the substance.
Consequently in this case also, a mechanical binding material is employed.
It has also been proposed to first produce glycerate of lead in the mass of lead
oxide; this only forms an intermediate product and in the process of "forming,"
the employment in the electrolyte of potassium permanganate is considered
necessary for breaking up the glycerine.
In contradistinction to this process, according to the present invention, a chemical
combination is employed, which, based on numerous experiments bearing on the
property that lead oxide possesses, of acting as an acid on strong bases, is effected
with the employment of pyridine substances, so as in no way to deteriorate the
conductivity of the plates. These researches showed that the pyridine substances
have the power to harden masses of lead oxide; it has however also been shown
that this is only possible if the lead oxide be given the opportunity of acting in
the form of a hydroxide or in the presence of water. It was moreover shown that,
in this way, lead oxides, (for example, litharge, minium or red lead), when brought
into contact with pyridine substances in the presence of water, possess, after drying,
sufficient solidity for them to be made into plates, and even to have greater cohesion
than the plates heretofore in use, whilst reducing the time required for "forming "
in an extraordinary degree.
.
According to observations made, the hardening of the lead oxide apparently
depends on the formation of a compound intermediate between lead hydroxide and
the pyridine bodies; possibly, in the presence of peroxide of lead, reduction of
he latter takes place, the oxidation products of the pyridine substances doubtless
olaying a certain rôle in the hardening of the material.
By reason of the short time required for "forming" (to 1 day) much time
and current is saved.
Consequently, according to the present invention, it is only necessary to knead
powdered lead oxide material (minium or red lead. litharge) with substances of the

page_text: pyridine group (such as pyridine, picoline, lutidine, etc.), in the presence of water,.
to a paste or dough, and to bring this dough into suitable forms. After drying, the
doughy mass hardens to a cohesive material which is subjected to the electric
"forming" process in the usual way. After forming," the active material remains
solidly united together.
Both pure pyridine as well as crude pyridine; such, for example, as that which is
present in hone- or animal-oil, may be employed, these substances being preferably
used in aqueous solution.
The electrodes made in this way are distinguished not only by their great
cohesion but also by their high capacity (100 ampère-hours per kilogramme
of positive active material) and, moreover, by extraordinary cheapness of
manufacture.
Dated this 1st day of August 1896
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
The Manufacture of an Improved Active Material for the Plates or
Electrodes of Electric Accumulators.
I, SIEGFRIED HAMMACHER, of 32 Andreas-strasse, Berlin, in the German
Empire, 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 :-
This invention relates to the manufacture of active material for the plates or
electrodes of electric accumulators, wherein the lead.oxides are firmly and solidly
held together by the employment, for this purpose, of substances of the "pyridine
group.
It has already been proposed to make accumulator plates, in which lead oxides
are formed into plates by means of solutions of the residues of tar-distillation in
alcohol, petroleum-ether, etc. and immersing them in dilute sulphuric acid, after
evaporation of the solvent. Here a mechanical binding or cementation only is
aimed at, this being effected by the residues of tar-distillation, which have an
undesirable influence on the conductivity of the plates..
It has, moreover, been proposed to mix lead oxide with butyric acid esters.
heating, saponification takes place, and, in the process of "forming," hydrocarbons,
carbonic acid, carbonic oxide, etc. and much resin are formed, the latter effecting
a mechanical binding or cementing together of the particles of the substance.
Consequently in this case also, a mechanical binding material is employed.
It has also been proposed to first produce glycerate of lead in the mass of lead
oxide; this only forms an intermediate product, and, in the process of forming,"
the employment in the electrolyte of potassium permanganate is considered
necessary for the purpose of breaking up the glycerine.
In contradistinction to this process, according to the present invention, a chemical
combination is obtained, based on numerous experiments bearing on the property
that lead oxide possesses, of acting as an acid on strong bases, in which chemical
combination pyridine substances are employed so as in no way to deteriorate the
conductivity of the plates. These researches showed that the pyridine substances
have the power to harden masses of lead oxide; it has, however, also been shown
that this is only possible if the lead oxide be given the opportunity of acting ia
the form of a hydroxide or in the presence of water. It was, moreover, shown
that, in this way, lead oxides (for example, litharge, minium or red lead), when

page_text: brought into contact with pyridine substances, in the presence of water, possess,.
after drying, sufficient solidity for them to be made into plates, and even to have
greater cohesion than the plates heretofore in use, whilst reducing, in an.
extraordinary degree, the time required for "forming."
According to observations made, the hardening of the lead oxide apparently
depends on the formation of a compound intermediate between lead hydroxide.
and the pyridine bodies; possibly, in the presence of peroxide of lead, reduction
of the latter takes place; the oxidation products of the pyridine substances.
doubtless also play a certain role in the hardening of the material.
By reason of the short time required for "forming" (to 1 day) much time
and current is saved.
Consequently, according to the present invention, it is only necessary to knead
powdered lead oxide material (minium or red lead, or litharge) with substances of
the pyridine group (such as pyridine, picoline, lutidine, etc.) in the presence of
water, to the consistency of paste or dough, and to bring this dough into.
suitable forms. After drying, the doughy mass hardens to a cohesive material
which is subjected to the electric "forming"
"forming," the active material remains solidly united together.
process in the usual way. After-
Both pure pyridine as well as crude pyridine, such, for example, as that which.
is present in bone- or animal-oil, may be employed, these substances being preferably
used in aqueous solution.
The electrodes made in this way are distinguished not only by their great
cohesion but also by their high capacity (100 ampère-hours per kilogramme
of positive active material) and, moreover, by extraordinary cheapness of
manufacture.
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 :-
First. The manufacture of active material for the electrodes of electric
accumulators, by mixing an oxide or oxides of lead with substances or bodies of
the pyridine group in the presence of water, whereby the said oxides of lead are
solidly bound together, so that, after drying, they may be subjected to the
"forming" process.
Second. An active material for the electrodes of electric accumulators, in which.
oxide of lead is mixed with substances or bodies of the pyridine group, substantially-
as herein before described.
Dated the 3rd day of May 1907
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,.
Agents for the Applicant.