Improvements in the Formation of Plates or Electrodes for Secondary Batteries.
Year: 1892

page_text: Date of Application, 9th July, 1892
Complete Specification Left, 9th Mar.; 1893-Accepted, 1st July, 1893
PROVISIONAL SPECIFICATION.
Improvements in the Formation of Plates or Electrodes for
Secondary Batteries.
I, GIUSEPPE GARASSINO of 92 Stanley Road, Carshalton, in the County of
Surrey, Electrician, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object the formation of accumulator plates with pure
crystalline peroxide of lead by the combined agency of electricity chemical action.
and heat. In order to form the pure crystalline peroxide, I immerse lead plates in a
bath of hot caustic potash dissolved in distilled or rain water, furnished with anode
& cathode plates connected to a dynamo, or other source of electricity, and with a
layer of litharge in the bath. The resulting peroxide is caused to assume the hard
crystalline form by immersing helical leaden grids in dilute acid, nitric, & then
applying the paste, which treatment brings about crystallization. The plates are
then subjected to pressure, & charged to saturation in a bath of hot dilute sulphuric
acid, which eliminates all occluded gases and prevents sulphating.
Dated this 9th day of July 1892.
GARASSINO GIUSEPPE.
COMPLETE SPECIFICATION.
Improvements in the Formation of Plates or Electrodes for
Secondary Batteries.
I, GIUSEPPE GARASSINO, Electrician, 92 Stanley Road, Carshalton County of
Surrey, 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 :-
The object of the present invention is to so construct the plates or electrodes for
secondary batteries that the spongy metallic lead of which same are composed shall
be intimately and securely attached to a rigid frame, whereby such plates or
electrodes will be prevented from becoming distorted and thus affecting the
efficiency of the accumulator, while such plates or electrodes will be much more
permanent than those hitherto employed, so that the life of the battery will be
considerably increased.
The method of forming my improved plates or electrodes is illustrated in the
accompanying drawings, in which
Fig. A, is a side elevation of the frame of the plates or electrodes.
Fig. B, a perspective view of the bath I employ for depositing the spongy
metallic lead thereon, and
Fig. C, a similar view showing the frames inserted in such bath, and the manner
in which they are connected to an electric source for the purpose of depositing the
spongy metallic lead thereon.
In carrying out my invention, I take bands or strips of pure lead, or antimonium-
lead (a mixture of antimony and lead), which I preferably twist into a spiral form
(as shown at 1 Fig. A). These strips 1 I place in a suitable mould and run lead
therein so as to form the border and terminal connections as shown at 2 in Fig. A.
This constitutes the frame of the plate or electrode.
Such frame I immerse for about 12 hours in a bath of water and nitric acid in
the proportion of 50 per hundred, whereby the pores of the lead constituting same
are opened.

page_text: On removing the frames from the bath I immerse them in a solution of caustic
potash and then wash them in pure water in order to entirely expel the nitric acid
from the pores of the metal.
The frames are then ready to receive the deposit of spongy metallic lead. For
this purpose I employ a bath preferably of the form shown in Fig. B, in which 1 is
a vessel which may be of lead or other suitable material, containing a solution
consisting of (1) distilled or rain water; (2) caustic potash in the proportion of
3 per 1000, and (3) litharge in the proportion of 8 per 1000. This vessel 1 is
inserted in an outer vessel 2 of any suitable material and which contains hot but
not boiling water.
This arrangement coustitutes a water bath for heating the solution contained in
vessel 1, and in which the deposition of the spongy metallic lead upon the electrode
frames is to be effected.
If the vessel 1, is of lead same may be made to serve as the anode, for which
purpose it will be connected (as shown at c Fig. C) to one pole of an electric source.
The electrode frames a will in this case be supported in the vessel 1, by means of
any suitable insulating material d, as shown on the right hand side of Fig. C. The
frames a will all be connected by suitable means to the other pole of the source of
electricity, as shown at b.
If the vessel 1, is not of lead, then the frames a placed therein will alternate
with plates of lead g, the former being connected to one pole of the source of
electricity and the latter to the other pole thereof, as shown at e and f on the left
hand side of Fig. C, where the last mentioned arrangement is shown.
The carrying out of the deposition of the spongy metallic lead in a warm bath
causes the pores of the metal frame to expand and open to the fullest extent, and
on the passage of a current through such bath the litharge is reduced to spongy
metallic lead, which by the chemical action of the current is conveyed into the
pores of the metal to which it firmly adheres. When a sufficient quantity of
spongy metallic lead has been deposited on the frame, the latter is removed from
the bath and subjected to pressure, preferably with a spatula or other flat
instrument, whereby the spongy metallic lead is compressed and the greater part
of the solution remaining therein is forced out. The electrode thus formed is then
immersed for about three hours in a bath of water and sulphuric acid at 50°°°
after which it is taken out and hung up to dry either in the open air or in au oven.
The electrodes are then ready for use in an accumulator.
They are arranged in the ordinary manner in a bath of warm water and sulphuric
acid at 1175 Densimetro or 19° Beaumé. The electric current is then made to
pass through until sufficiently charged, when at the positive the spongy lead is
reduced to pure crystalline peroxide, and at the negative to pure reduced lead.
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 formation of electrodes for secondary batteries, by electrolytically
depositing lead in a spongy metallic form upon leaden frames in a warm bath
composed of water, caustic potash and litharge.
2. In the formation of the electrodes of secondary batteries, of a frame of lead or
antimonium lead, which has been previously treated in a bath of nitric acid and
water, and then washed, first in a solution of caustic potash and then impure water,
the precipitation of lead in a spongy metallic form upon such frame by means of an
electric current in a warm bath consisting of a solution of caustic potash and
litharge, substantially as specified.
Dated this 15th day of June 1893
ALLISON BROS.,
Agents for the Applicant.