Process for Hardening and Rendering Tenacious the Active Mass of Electric Accumulators.
Year: 1898

page_text: Date of Application, 12th Mar., 1898-Accepted, 4th Mar., 1899 y b
'I..
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Process for Hardening and Rendering Tenacious the Active Mass
of Electric Accumulators.
I, RODERICH VON BARBY, of 6, Kyffhäuserstrasse, Schöneberg, near Berlin,
Germany, Retired Captain, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by, the following statement:-
Lead oxides, red lead, litharge or inorganic lead salts (carbonate or acetate of
lead) are moistened with distilled water sufficiently to render the mass just
capable of kneading and the mass thus attained is affixed by suitable means to
netting, frames or the like and then placed in a suitable drying room, and
about half dried. At this point of the process and by means of suitable apparatus
a vaporisation of suitable organic substances is effected and the mass is not only
completely dried by the heat of these vaporised organic, substances, but the lead
oxides vaporised are gradually converted into organic conducting and decom-
posable lead combinations.
In carrying out the process red lead is mixed with distilled water until the
mass is just capable of kneading, it is then partially dried, i.e. dried for about
12 hours the whole drying process occupies about 24 hours and at this stage
indigotin or acetic acid, phenol or alizarin or pyroracemic acid or other organic
substance, capable of forming plumbates or salts with the lead oxides in the
presence of heat, is introduced into the drying furnace or oven and caused to
steam or vaporise therein. The drying process is completed in the presence of
these substances.
The amount of the substance introduced into the oven varies according to the
construction of the oven, to the thickness and superficial area of the accumulator
plates being treated, and to the number of the same treated at one time, as also,
to the degree of hardness which it is desired to impart to the electrodes.
Thus, for instance, if pyroracemic acid is employed, 1 kilo. of the same would
suffice for 100 kilo. lead oxide and the temperature at which it would vaporise
is about boiling point, or at the melting point of the substance employed.
In short, in carrying out the process the organic substance must be introduced
into the drying oven when the mass is about half dry and must be caused to
vaporise so as to produce vapours which play around the accumulator plates
during the last half of the time they require to be properly dried.
The processes hitherto known for producing a durable active mass for electric
accumulators consist in introducing the substances forming the binding means
to the lead oxides, before the whole is formed to a paste. The workmen engaged
in this operation come into close contact with the generally poisonous binding
means (phenol, aloin, santonin, conein, morphin etc.) which are dangerous to
health, then again, during the process of pasting, most of the solvant of the
substances, evaporated, as also, to a certain extent, the substance itself, which
was thus lost to the paste.
In drying the substances decomposed to a certain extent or became chemically

page_text: changed so that they rather tended to decrease than increase the efficiency of
the active mass.
The advantages accruing from the above described novel process are so obvious
that it will not be necessary to go more closely into the distinctions between it
and the older processes here.
It should however be mentioned that in practice, according to the processes
hitherto known 75 ampère hours, per kilogram mass could be attained by very
careful management (.e. if the binding means were dissolved in alcohol, ether,
collodium etc. and then added in certain proportions of the active mass, to the
lead oxides).
According to the process herein before set forth, 127 ampère hours capacity
per kilogram active, positive mass may easily be obtained.
In view of the fact that 123 ampère hours capacity represent the whole
theoretical output of a kilogram of superoxide of lead, .e. 100%, the advantage
of the present process will at once be rendered evident."
'
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
A process for rendering the active mass of electric accumulators chemically
tenacious, which consists in first mixing the lead oxides, without the addition
of any binding means, with pure water, and applying the same to metal frames
or nettings, and then half drying the same and completing the drying process
by means of the gases of vaporised organic substances, of known kinds, which
possess the property of forming durable and conductive combinations with the
lead oxides, substantially as described..
11: 101
1
100D
CASTLE SMITH,
"Invention" Office, Mitre Court, Fleet Street, London, E.C.,
Agent for the Applicant.