Improvements in the Manufacture of Electrodes or Plates for Electrical Batteries.
Year: 1889

page_text: Date of Application, 10th Oct, 1889
Complete Specification Left, 11th Aug., 1890-Accepted, 4th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Electrodes or Plates for
Electrical Batteries.
I, Dr. PAUL SCHOOP, of Victoria Road, Charlton, in the County of Kent, Chemist
do hereby declare the nature of this invention to be as follows:-
My invention has reference to the manufacture by an electro-chemical process of
electrodes or plates (hereinafter called electrodes) for electrical batteries and especially
for use in secondary batteries.
For this purpose a compound soluble lead salt such as hereinafter described is
decomposed by an electric current, its constituent parts being deposited upon suitably
shaped conducting plates or supports. These conducting plates or supports may be
nade of interlaced or woven threads or wires of material that will not be acted upon
by the electric current or by the electrolyte used, and such for example as gold,
platinum, antimony or lead. The plates or supports instead of being of woven or
network form may each be in the form of a grating or perforated metal plate or frame
produced by casting or otherwise; or a plain plate may be used as the base or
foundation for an electrode to be prepared according to this invention.
As examples of compound soluble lead salts suitable for my electro chemical process
there may be mentioned lead salts such as lead sulphate combined with an alkaline salt
such as a sulphate of an alkali; or a compound lead salt such as a lead salt of an
organic sulpho acid, combined with a lead salt of an inorganic acid and with or
without a salt of an alkali may be used. Such a compound salt may be prepared
by mixing sulpho-glycerine acid or naphthalin-sulpho-acid, or both, with sulphuric
acid and adding thereto an oxide or carbonate of lead and one or more of the
alkalies, potash, soda, or ammonia, until the acids are neutralized or saturated.
The relative proportions of the substances may be varied. In lieu of or in addition
to the lead salt or salts of the sulpho-acid or acids mentioned, I may sometimes
employ other soluble organic salt of lead, as for example acetate of lead or tartrate
of lead or both. The presence of an alkali in the lead solution has no injurious
action on the deposit produced upon the conducting plates or supports by the
A suitable lead solution for the
electrolytical decomposition of the lead solution.
manufacture or production of electrodes according to this invention is prepared as
follows: One volume of glycerine is mixed with from one to three volumes of
concentrated sulphuric acid and the mixture is neutralized with a lead base such
as white lead, litharge or red lead. To this mixture is added an inorganic lead-
salt, for example lead sulphate, and an alkaline salt, for example sulphate of
ammonia. In the solution thus obtained, and which may advantageously be heated,
are suspended the plates or supports to serve as the base or foundation for the
active electrodes, and an electric current is passed through the solution until the
electro-chemical layer or deposit on the plates or supports is of the required
thickness. The electrodes thus prepared can then be arranged together to form the
elements of a battery. The electro-chemical deposit or layer instead of being produced
on the plates or supports whilst suspended in the solution of a lead salt or salts such as
herein before mentioned, may be produced by dipping the plates or supports in such
solution, then transferring them to another solution such as that of a free acid, for
example one of those herein before mentioned and then electrolytically decomposing the
ead compound on the plates or supports, the operation being repeated if necessary,
until the desired thickness of the electro-chemical layer or deposit is obtained.
Dated this 10th day of October 1889.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Electrodes or Plates for
Electrical Batteries.
I, Dr. PAUL SCHOOP, of Victoria Road, Charlton, in the County of Kent, 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 has reference to the manufacture by an electro-chemical process of
electrodes or plates (hereinafter called electrodes) for electrical batteries and especially
for use in so-called secondary batteries.
The negative plates are provided with a coating of lead, and hydrogen which is the
active part of the negative plate during the discharging period, while the positive plates
are provided with a coating of a highly oxidised body, such as the so called peroxide
of lead.
For this purpose a compound soluble lead salt, such as hereinafter described, is
decomposed by an electric current, its constituent parts being deposited upon
suitably shaped conducting plates or supports. These conducting plates or supports
may be made of interlaced or woven threads or wires of material such as gold,
platinum, carbon, antimony or lead. The plates or supports, instead of being of
woven or network form, may each be in the form of a grating or perforated metal
plate or frame produced by casting or otherwise, as well understood; or a plain
plate may be used as the base or foundation for an electrode to be prepared according
to this invention.
As examples of compound soluble lead salts suitable for my electro-chemical process,
there may be mentioned lead salts such as lead sulphate combined with an alkaline
salt such as a sulphate of an alkali; or a compound lead salt such as a lead salt of an
organic sulpho-acid, combined with a lead salt of an inorganic acid, and with or with-
out a salt of an alkali may be used. Such a compound salt may be prepared by mixing
sulpho-glycerine acid or naphthalin-sulpho-acid, or both with sulphuric acid and adding
thereto an oxide or carbonate of lead and one or more of the alkalies, potash, soda,
or ammonia. The relative proportions of the substances may be varied. In lieu of or
in addition to the lead salt or salts of the sulpho-acid or acids mentioned,
sometimes employ other soluble organic salt of lead as for examples, acetate of lead, or
tartrate of lead, or both. The presence of an alkali salt in the lead solution is some-
times advantageous to the deposit produced upon the conducting plates or supports by
the electrolytical decomposition of the lead solution.
may
A solution of a compound soluble lead salt consisting of an inorganic lead salt
combined with an alkali, suitable for the manufacture of electrodes according to this
invention can be prepared by adding 1 part by weight of lead sulphate and 1 part
by weight of nitrate of ammonia to 10 parts by weight of water.
A suitable solution containing an organic salt and an inorganic salt, can be prepared
by mixing 1 part by weight of tartrate of lead and 1 part by weight of sulphate of
lead with 20 parts by weight of water and heating the mixture until the salts are
wholly or partially dissolved. An addition of tartrate of ammonia facilitates the
dissolving of the aforesaid lead salts.
A suitable solution containing an organic salt, an inorganic salt and an alkaline
salt can be prepared as follows:-One volume of glycerine is mixed with from one to
three volumes of concentrated sulphuric acid and to the mixture which is diluted with
about 12 volumes of water, is added about 5% (of the weight of the diluted mixture)
of a base such as white lead, litharge or red lead. To the mixture thus obtained is
added about 5% of an inorganic lead salt, for example lead sulphate, and about 5%
of an alkaline salt, for example sulphate, chloride or nitrate of ammonia.
In either of the solutions thus obtained, and which may advantageously be heated
to a temperature of say about 85° C., are suspended the plates or supports to form
electrodes which are connected with the poles of an electric generator, and an electric

page_text: current is passed through the solution in the ordinary manner until the electro-chemical
layer or deposit on the plates or supports is of the required thickness. In this manner
the plate, or group of plates, connected to the negative pole of the electric generator
will be formed with a coating of finely divided or spongy lead containing hydrogen,
and the plate, or group of plates, connected to the positive pole will be formed with
a coating of oxide of lead, or of oxidised lead in combination with an alkali, as for
examples, the potassium, sodium, or ammonium salt of plumbic acid. The positive
and negative electrodes thus prepared are then ready for use in a battery.
The electro-chemical deposit or layer instead of being produced on the plates or
supports whilst they are suspended in the solution of a compound lead salt or salts
such as herein before mentioned, may be produced by dipping the plates or supports
in such solution, allowing the solution to dry thereon, then transferring them to a
bath such as that of a free acid, for example one of those herein before mentioned and
then electrolytically decomposing the lead compound on the plates or supports, the
operation being repeated.if necessary, until the desired thickness of the electro-chemical
layer or deposit is obtained.
Having now particularly described and ascertained the nature of this inven-
ion and in what manner the same is to be performed I declare that what I
"laim is :-
C
1. The formation of a negative electrode having a coating of finely divided or
spongy lead and a positive electrode having a coating of a highly oxidised lead com-
pound, by passing an electric current through conducting plates or supports whilst
suspended in or coated with a solution of a compound soluble lead salt substantially as
herein described.
2. The formation of a negative electrode having a coating of finely divided or
spongy lead, and a positive electrode having a coating of highly oxidised lead com-
pound, by placing conducting plates or supports in a solution of an organic lead salt
and passing an electric current through the solution and the plates or supports
substantially as herein described.
3. The formation of a negative electrode having a coating of finely divided or
spongy lead and a positive electrode having a coating of a highly oxidised lead
compound, by placing conducting plates or supports in a solution of a compound lead
salt consisting of an organic lead salt and an alkaline salt, and passing an electric
current through the solution and the plates or supports substantially as herein
described.
4. The formation of a negative electrode having a coating of finely divided or
spongy lead and a positive electrode having a coating of a highly oxidised lead
compound, by placing conducting plates or supports in a solution of a compound lead
salt consisting of an inorganic lead salt and an alkaline salt, and passing an electric
current through the solution and the plates or supports substantially as herein
described.
5. The formation of a negative electrode having a coating of finely divided or
spongy lead and a positive electrode having a coating of a highly oxidised lead
compound, by placing conducting plates or supports in a solution or an organic lead
salt and an inorganic lead salt, and passing an electric current through the solution
and the plates or supports substantially as herein described.
6. The formation of a negative electrode having a coating of finely divided or
spongy lead, and a positive electrode having a coating of a highly oxidised lead
compound, by placing conducting plates or supports in a solution containing an
organic lead salt, an inorganic lead salt, and an alkaline salt, and passing an electric
current through the solution and the plates or supports substantially as herein
described.
7. The formation of a negative electrode having a coating of finely divided or
spongy lead, and a positive electrode having a coating of a highly oxidised lead
compound, by placing conducting plates or supports in a solution prepared by mixing

page_text: glycerine with concentrated sulphuric acid, diluting with water and then adding
thereto first, a lead base, such as oxide or carbonate of lead, and afterwards an inorganic
lead salt, and an alkaline salt, and passing an electric current through the solution
and the plates or supports substantially as herein described.