Improvements in and relating to Electric Accumulators.
Year: 1898

page_text: Date of Application, 26th Feb., 1898-Accepted, 16th Apr., 1898
[Communicated from abroad by REINHOLD KNOSCHKE, of 61, Elisenstrasse, Leipzig..
Saxony, in the Empire of Germany.]
Improvements in and relating to Electric Accumulators.
I, CHARLES JUNGE, of 75, Chancery Lane, London, W.C., Consulting 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 :-
My invention relates to electric accumulators and more especially to the
manufacture of the active material. Use is made of spongy lead, which is produced
in a peculiar manner and is of a quality rendering it especially suitable for the
desired purpose, in conjunction with other substances which impart considerable
strength to the spongy lead, only a comparatively small percentage of such
substances being added. The porosity of the spongy lead is not affected at all by
the addition of the said substances.
The spongy lead forming the principal constituent of the active material to be
produced is made in the following manner. Metallic lead is boiled at a moderate
heat in 10 to 20 per cent. nitric acid for from 5. to 10 minutes, such boiling being
continued only so long as it does not cause the formation of crystals. Now the
fluid is cooled and after having removed the lead I place zinc, coke or coal in the
form of strips, bars or rods in the fluid. These strips, bars or rods will be covered
in a short time by an exceedingly fine precipitate of spongy lead, which is removed
from the strips, bars or rods by stripping, whereupon the manufacture of the
active material is continued.
The texture of the spongy lead obtained in this manner is exceedingly fine
without being muddy, therefore this spongy lead is especially adapted to form a
strong, metallic and at the same time very porous layer when mixed with
comparatively small quantities of other substances.
The most important of these substances is pulverized manganese peroxide. In
the manufacture of positive electrodes a small quantity of minium may be added,
whilst in the manufacture of negative electrodes lead oxide is added. By this
means the adhesion of the active material to the leaden frame will be increased.
By mixing the spongy lead, which is in an exceedingly fine condition, with
manganese peroxide I produce an active material the cohesion of the molecules of
which is considerable as is also the porosity of the same, whilst the metallic quality
of the active material ensures a very great capacity. Electrodes made in this
manner can be formed in a comparatively short time, as the reduction takes place
very rapidly, but neither of these advantages will entail the strains to which plates
have hitherto been subjected in the charging or discharging, usually giving rise to
deformations which cause the active material to crumble off. For this reason I
may use leaden frames which are very thin and light so that the weight of the
accumulator will be considerably lessened. Excessive strains to which accumulators
made according to my said invention have been submitted have not caused such
inconveniences as arise in accumulators of the customary shapes. It will thus be

page_text: seen that electrodes made of the aforesaid active material have a capacity and a
durability such as has not heretofore been realized.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
First. A process of manufacturing active material for accumulators, in which
spongy lead of an exceedingly fine texture is first produced by boiling lead in
dilute nitric acid, the boiling operation being stopped before the formation of
crystals begins, and by immersing strips, rods or bars of zinc, coke or coal therein,
whereupon pulverized manganese peroxide is added to the spongy lead, substantially
as set forth.
Second. A process of manufacturing active material for positive electrodes of
accumulators, in which spongy lead of an exceedingly fine texture is first produced
by boiling lead in dilute nitric acid, the boiling operation being stopped before the
formation of crystals begins, and by immersing strips, rods or bars of zinc, coke or
coal therein, whereupon pulverized manganese peroxide mixed with minium is
added to the spongy lead, substantially as set forth.
Third. A process of manufacturing active material for negative electrodes of
accumulators, in which spongy lead of an exceedingly fine texture is first produced
by boiling lead in dilute nitric acid, the boiling operation being stopped before the
formation of crystals begins, and by immersing strips, rods or bars of zinc, coke
or coal therein, whereupon pulverized manganese peroxide mixed with litharge is
added to the spongy lead, substantially as set forth.
Dated this ofth
1000
J. LINCOLN & Co.,
75, Chancery Lane, London, W.C., Agents for the Applicant.