IMPROVEMENTS IN AND RELATING TO ELECTRICAL ACCUMU- LATORS OR SECONDARY BATTERIES
Year: 1885

page_text: Secondary Batteries.
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and C, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS IN AND RELATING TO ELECTRICAL ACCUMU-
LATORS OR SECONDARY BATTERIES " to be as follows:-
This invention relates to electrical accumulators or secondary batteries in which
plates of crystallized chloride of lead are employed, and to the preparation of the
said plates.
In preparing the said plates I liquefy in a porcelain capsule, chloride of lead, to
which I then add a quantity of chloride of zinc. This quantity, which is always
smaller than that of the chloride of lead, varies between the limits of from
3 to 10% I agitate the mixture and permit it to cool, and I pour it, quite liquid,
into a mould of thick lead, porcelain, or platina, or of any other suitable substance.
I thus obtain a double chloride of lead and of zinc, or at least a mixture of these
two chlorides.
The presence of chloride of zinc has the effect of preventing the chloride of lead
from breaking by cooling, and of ensuring great porosity of the mass by the
elimination of the chlorine first and of the zinc afterwards.
The liquefied chloride of lead employed alone (as in the Marié Davy pile and its
imitations) has the inconvenience of breaking, (in solidifying) which does not occur
with the double chloride. Hence it is not necessary to unite pieces, or to keep
them together by a net of platina or lead wire, the improved chloride of lead
remaining unbroken.
During the solidification of the mixture, a rod, having a greater or smaller
number of branches of platina or lead or of any other material conducting electricity,
and capable of resisting the action of the sulphuric acid even under the influence
of electricity, is inserted as an internal support. Such internal support may,
however, be dispensed with, and an external support, or a frame of cast or rolled
lead he used, being placed either upon the plate in the state of chloride, or upon
the crystallized chloride of lead which is obtained as hereinafter described.

page_text: In order to thoroughly crystallize the chloride of lead I proceed as follows, that
is to say I mix with the chloride of lead from 3 to 6% of chloride of zinc and
I immerse the plate of double chloride, which is cast in contact with a sheet of zinc,
in any saline solution, preferably a concentrated solution of chloride of zinc,
provided that the reaction only produces chloride of zinc, and that the liquid is
saturated in order that it shall not dissolve the cast double chloride.
I can mount the plates of double chloride in piles, in this liquid, against zinc,
and even accelerate the reaction by the passage of an electric current from an
external source.
As regards the electric current which results from the reaction itself, I do not
intend to utilize it, because, although sufficiently constant, it is of feeble intensity
and electro-motive force.
When a plate of the double chloride is dipped between two sheets of zinc, a
crystallization takes place, needles being formed which divide the surfaces in the
direction of the thickness, the plate being, in fact, found divided on a plane parallel
to the surfaces. If there is only one sheet of zinc, the crystalline needles of chloride
of lead extend over the entire thickness of the plate.
In this manner I easily obtain plates of any desired dimensions, consisting of
chloride of lead in the form of beautiful crystals.
After thorough washing for eliminating the chloride of zinc, immersing in water
acidulated with sulphuric acid for dissolving the metallic zinc, and renewed washing
with water, I dry by means of a gentle fire, in order to augment the consistency of
the crystalline mass of chloride of lead.
I then mount the secondary battery in the ordinary manner in water acidulated
with sulphuric acid, or in a solution of a metallic salt susceptible of electrolysis.
It then accumulates very rapidly.
A much stronger current may be employed with the improved battery than with
other systems. I can go beyond 60 ampères.
The improved plates, if they have been well prepared, are after peroxidation very
hard, smooth, and even sonorous when struck.
The oxidation of the plate can be accelerated either in the dry way by causing
it to pass, at a suitable temperature, through a current of oxygen or of air, or
simply by heating it in the free air; or in the humid way in an oxidizing liquid,
with or without the action of an electric current.
The chloride of zine can be replaced by other chlorides, especially by chloride of
copper or even by any other salt, or binary metallic substance, provided that it is
fusible and capable of uniting intimately with the salt of lead by fusion.
As regards the proportion of the chloride of zinc or of the salts which replace it,
I may vary the same according to requirements so as to obtain plates which are
more porous, in proportion as I employ more chloride, and consequently lighter;
for instance I have added 4% of chloride of zinc, the plate will have a density
lower than 4.
Dated this 2nd day of March 1885.
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: Improvements in and relating to Electrical Accumulators or
Secondary Batteries.
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co Patent Agents,
Southampton Buildings, in the County of Middlesex 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 electrical accumulators or secondary batteries in which
crystallized chloride of lead is employed, and to the preparation of the plates
therefor.
In preparing the said plates I melt or liquify, in a porcelain capsule, chloride of
lead, to which I then add a suitable quantity of chloride of zinc. This quantity,
which is always smaller than that of the chloride of lead, varies between the
limits of 3 per cent and 10 per cent. I agitate the mixture and permit it to cool,
or I pour it in a liquid state into a mould of thick lead, porcelain, platinum or
other suitable substance which cannot be attacked by the chlorides and whose
co-efficient of expansion is lower than that of the said chlorides, in order to
facilitate the withdrawal and consequently the disengagement of the moulded
plate in a single piece. I thus obtain a double chloride of lead and zinc or at
least a mixture of these two chlorides.
The presence of chloride of zine has the effect of preventing the breakage of
the chloride of lead by cooling, and of ensuring great porosity of the mass by the
elimination first of the chlorine and then of the zinc.
1
The cast chloride of lead employed alone (as in the Marié Davy battery and
imitations thereof) has the inconvenience of being liable to breakage, which is
obviated by the use of the said double chloride. Therefore it is not necessary
either to place the pieces in a bag or to keep them together by a net of platinum
or lead wire; the improved chloride of lead remaining unbroken and not requiring.
any devices to keep it together.
During the solidification of the mixture, a rod, having a greater or less number
of branches of platinum or lead or other conductor of electricity and capable of
resisting the action of sulphuric acid even under the influence of electricity, is
inserted as an internal support. Such internal support may, however, be dispensed
with and an external support or frame of cast or rolled lead be used, which support
or frame is placed either upon the plate in the state of chloride, or upon the
crystallized chloride of lead which is obtained as hereinafter described.
:-
In order to obtain chloride of lead which is completely and solidly crystallized,
I proceed as follows, that is to say I mix with the chloride of lead from
3 per cent to 6 per cent of chloride of zinc and I immerse the cast plate of double
chloride in contact with a sheet of zinc in a saline solution, preferably a
centrated solution of chloride of zinc, taking care that the reaction only produces
chloride of zinc and that the liquid is saturated in order that it shall not dissolve
the cast double chloride.
con-

page_text: I can mount the plates of double chloride in a battery in this liquid against
zinc, and, if desired, accelerate the reaction by the passage of an electric current
from an external source.
As regards the electric current which results from the reaction itself, I do not
intend to utilize it, because, although sufficiently constant, it is of feeble intensity
and small electromotive force..
When a plate of the double chloride is immersed between two sheets of zinc,
a crystallization takes place, needles being formed which divide the surfaces in the
direction of the thickness, and the plate is thus divided on a plane parallel to the
surfaces. If there is only one sheet of zinc, the crystalline needles of chloride of
lead extend throughout the entire thickness of the plate.
In this manner I easily obtain plates of any desired dimensions, consisting of
chloride of lead in the form of beautiful crystals.
After thorough washing of the plates to eliminate the chloride of zinc, immer-
sion thereof in water acidulated with sulphuric acid to dissolve the metallic zinc,
and renewed washing with water, 1 dry the said plates by means of a gentle heat
to augment the consistency of the crystalline mass of chloride of lead.
I then arrange the accumulator or secondary battery in the ordinary manner in
water acidulated with sulphuric acid, or in a solution of a metallic salt susceptible
of electrolysis. It can then be charged very rapidly.
For charging the accumulator, a must stronger current may be employed than
with other systems; it may be above 60 ampères.
The improved plates, if they have been well prepared, are, after peroxidation,
very hard, smooth, and sonorous when struck.
The oxidation of the plate can be accelerated either by the dry process by
causing it to be traversed at a suitable temperature by a current of oxygen or of
air, or simply by heating it in the open air; or by the wet process in an oxidizing
liquid with or without the action of an electric current.
The chloride of zinc can be replaced by other chlorides, more especially chloride
of copper, or by any other salt or metallic binary compound provided that it is
fusible and capable of uniting intimately with the salt of lead by fusion.
As regards the proportion of the chloride of zinc, or of the salts which replace it,
I may vary the same according to requirements, so as to obtain plates which are
more or less porous and lighter or heavier as desired, the porosity and consequently
the weight being in proportion to the quantity of chloride employed, (for instance,
if 4 per cent of chloride of zinc is added, the plate will have a density lower
than 4).
The liquid of the chloride of zinc may be replaced by a solution of sal ammoniac
more or less concentrated, or sal aminoniac may be substituted for the chloride of
zine for the fusion of the plate, which would then be composed of a double chloride
of lead and ammonium, or of a mixture of these two chlorides, or even of a simple
chloride of lead.
Moreover I can employ a solution of chloride of sodium and chloride of iron,
with a negative plate either of zinc, iron, lead nickel or platinum; the two last
named metals more especially when sal ammoniac is employed, in order to avoid a
metallic deposit by electrolysis.
Very beautiful results are obtained (very brilliant crystals of lead) and the
difficulties of the elimination of the chloride added to that of the lead are avoided,
by putting 7 per cent of sal ammoniac in small pieces into the cast chloride of lead.
The plates do not break by cooling, and, when arranged in a battery in a concen-
trated solution of sal ammoniac, they are reduced to simple lead; and a washing
with water is sufficient to completely free the lead from foreign matters; these
plates can be charged in an accumulator as positive plates in three hours under a
current of six ampères.
The improved plates being cast, as above stated, of a simple chloride of lead and
of another radical including chloride of ammonium, I can immerse them in a
solution of sal ammoniac or other chloride or oxy-chloride in presence of another

page_text: electrode, not soluble (such as lead, carbon, platinum) and I subsequently cause a
current (say, of from 3 to 4 ampères) to enter by the latter and depart by the
plate; the reduction into lead is then very rapid; and the plate solid.-Furtherinore,
if a plate is placed in a mixture of chloride of lead and chloride of zinc, the latter
easily dissolves. In practice, one per cent of the chloride of zinc in the chloride of
lead is sufficient to prevent breakage of the plates.
:
Instead of forming the plates of any simple or double chloride of lead, as above
described, I sometimes form them of oxy-chlorides of lead either of the yellows
of Cassel, Turner or others, or of a mixture of chloride of lead and litharge,
massicot or red lead in variable proportions as desired. In all cases, I can cast the
material in porcelain or earthenware (la terre de Hesse), and I prefer to run it into
my closed load mould composed of two shells, the plates thus obtained not being
liable to breakage by cooling. They only require to be heated to a more elevated
temperature. I prefer, in order to reduce them to a metallic state, to use a con-
centrated solution of sal ammoniac, especially if they are arranged in a battery
against zine; but I can also employ a solution of another chloride, and, in all cases,
I can, in order to avoid the introduction of the zine, opposed to the unreduced
plate a non-soluble electrode (such as lead. platinum or carbon) and cause to
intervene a current from an external source, since in this case there is no battery.
I can also avoid the employment of compounds of other metals than lead.
I obtain plates of simple chloride of lead by mixing therewith, when in a molten
state, asbestos; the fibres of this substance entirely, or almost entirely, prevent the
breakage of the plate by cooling; but even in cases where the plates break or ck.
the pieces are retained in position and form a single mass of an
which is easily reduced to metal as above described. I find, moreover, that by this
process a considerable advantage is obtained; I do not require, by this means, to
eliminate the substances other than chloride of lead which 1 use for preventing
breakage. Instead of asbestos I can employ any other substance, whether a
conductor or not, in threads, fibres, or woven fabrics, provided the said substances
cannot he chemically attacked by the cast chloride of lead.
1 sometimes employ a solution of carbonate of ammonia for the reduction of the
plate of simple chloride or double chloride of lead. Moreover, in some cases, the
apparatus can be used as an electric battery, a solution of hydrochlorate of ammonia
being used as the liquid.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed as communicated to me
by my foreign correspondent I declare that what 1 claim is
First. The manufacture of plates for accumulators or secondary batteries, without
fracture or crack, by means of chloride of lead cast with chloride of zinc, the zinc
being subsequently removed by sulphuric acid, whereby plates of chloride of lead
having a suitable degree of porosity are produced.
Second. The employment of oxygen, air and heat for producing a primary
oxidation of the aggregated reduced lead.
Third. The employment of closed moulds of thick lead, platinum, or other metal
which cannot be attacked by the chlorides and whose co-efficient of expansion is
lower than that of the said chlorides, in order to facilitate the withdrawal and
consequently the disengagement of the moulded plate in a single piece.
Fourth. The employment, as the liquid, of chloride of zine or a solution of sal
ammoniac, the latter salt being in some cases used in place of the chloride of zinc
for the fusion of the plate.
Fifth. The employment of a solution of chloride of sodium and chloride of iron
with a negative plate of zinc, iron, lead, nickel, platinum or other metal.
Sixth. The immersion of the plates composed of a simple chloride of lead or a
double chloride of lead and another radical, in a solution of sal-ammoniac or other
chloride, in presence of another insoluble electrode and the passage of an electric
current from an external source to effect the rapid reduction of the lead.

page_text: Seventh. The employment of oxy-chlorides of lead in the manufacture of the
said plates.
Eighth. The employment of a solution of carbonate of ammonia for the reduc-
tion of the plate composed of simple chloride or of double chloride of lead.
Ninth. The application of the apparatus as an electric battery, a solution of
hydrochlorate of ammonia being used as the liquid.
Tenth. The employment of asbestos or other fibrous substance mixed with the
chloride of lead to prevent the breakage of the plates and to impart a suitable
porosity thereto.
Eleventh. The improved electrical accumulator or secondary battery provided
with plates of crystallized chloride of lead, substantially as above set forth.
Dated this 2nd day of December 1885.
HASELTINE, LAKE & Co.,
For the Applicant.