Improvements in Electrical Accumulators.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electrical Accumulators.
I, EDWARD HEYL of 236, Great Clowes Street, Higher Broughton, Manchester,
Electrical Engineer do hereby declare the nature of this invention to be as
follows,-
This invention relates to improvements in connection with secondary batteries
or electrical accumulators and is intended to provide a positive electrode which will
present a large surface to the electrolyte and at the same time possess great
strength and stability. The positive electrode of a secondary battery is formed
from per-oxide or super-oxide of lead which is reduced to metallic lead during the
working of the accumulator. These positive electrodes are generally made in one
of two types in the first of which lead plates are employed, formed so as to give a
large surface, and in the other a paste is employed, forming a porous plate so that
a much larger surface is produced. As the capacity of the accumulator depends
largely upon the surface of the lead exposed to the action of the electrolyte, the
greater the surface obtained the more efficient is the accumulator. At the same
time positive plates as hitherto constructed have been liable to break down after
a short use. In the case of the paste grid-plates the active material drops out of
the grids and the grids themselves get attacked by the electrolyte.
My invention provides an arrangement by which a very large surface is
obtained, while at the same time the plate is not injured in any way by rapid
charging and discharging, and the accumulator may even be completely
discharged without injury.
I propose to make the lead, or other metal or alloy employed for this purpose
in the form of fine threads so that the metal has an appearance somewhat similar
to that of cotton wool. The lead wool so formed is pressed into plates of the
desired size and form. The threads, although pressed closely together provide a
very large surface, the plate being completely porous. A plate of this kind can
be changed into super-oxide of lead in a very rapid manner so that almost the
whole of the lead can be utilised, obtaining a very high capacity.
Instead of
employing lead wool, the metal may be formed into fine strips.
A plate formed according to this method from fine threads or strips of lead or
other material would be liable to get rapidly destroyed and drop to pieces. To
prevent this I propose to dissolve india rubber in a suitable solvent forming a
strong solution. Into this solution I introduce a quantity of chromate of lead or
other substance which will remain suspended in the solution. The lead wool is
dipped into this solution before being formed into the plates, or the plates them-
selves may be dipped into the solution after formation. The thickness of the
rubber film formed on the finely divided lead depends upon the degree of con-

page_text: centration of the solution, and the film may be increased by successive coatings.
After drying, the rubber is vulcanised. This may be done by the wet chloride of
sulphur process, or sulphur may be mixed in a dry state with the rubber solution
before dipping the plate or dissolved in carbon bisulphide or other solvent which
will mix with the rubber solution. After the rubber skin covering the lead
threads in the plate has been vulcanised, the plate is exposed to the action of an
electric current. The material, such as chromate of lead, mixed with the rubber
solution will be dissolved in the electrolyte so that the rubber covering, after this
action is completed will be filled with minute holes, allowing the electrolyte to
penetrate and attack the fine lead threads. The lead is thus formed into super-
oxide which is supported by the rubber skin, the threads expand on being changed
into peroxide, but as the rubber also expands freely it will not allow the material to
break down.
The suspended material in the rubber may be dissolved out of the rubber skin
by treating the plate with a suitable dissolving medium which will produce the
desired effect without attacking the rubber. The rubber can thus be rendered
porous without the use of the electric current. The rubber may also be rendered
porous without adding any suspended material by heating the plate and
evaporating the solvent the escaping gases giving the rubber a spongy texture.
To allow the plates to expand freely they are perforated by a series of holes at
a suitable distance this giving a greater surface for expansion without any danger
of the plate buckling or curving.
This process may also be applied to the grids of paste accumulators. Before the
paste has been applied, the grids are covered with spongy vulcanised rubber in the
manner above described so that they are protected from the corrosive action of
the electrolyte. After the paste has been applied and the plate formed, the latter
may be covered in a similar manner with spongy rubber, thus keeping the active
material in its place and preventing the gas developed in charging the accumu-
lator from tearing off particles, which in the present arrangement rapidly destroys
the plate. Instead of india rubber any suitable gum such as balata may be
employed the method of treating the plates being similar.
The rubber covering for the lead wires or threads may, instead of being
formed by a solution into which the lead is dipped, be wound around the wires.
According to this method, lead wires are formed by any suitable method, of
circular, triangular, square, or other cross section, and are then partly covered
by a thin strip of rubber wound on them in a spiral manner by a suitable machine.
A number of these wires, the number depending on the size of plate required, is
taken and woven or twisted together by a rope making or other machine
and compressed into the thickness desired.
The rubber is vulcanised before or after the plate is formed, either by mixing
sulphur with the rubber in steam or by the wet process. The resulting plate is
thus of honey-comb structure, with lead wire separated and supported by
vulcanised rubber. The same may be filled with paste, if desired. The lead wires
may be braided with the rubber strips or each strip may be perforated and placed
on longitudinally. Grids for paste accumulators may also be protected in this
manner. Instead of using lead wire, strips or grids protected by an elastic
material covering the same partly, hellow wire, or strips, or grids may be applied,
the whole being filled with an elastic core of vulcanised or unvulcanised rubber or
another suitable material.
With plates formed according to my invention from lead wool or fine lead strips
or grids and supported in the manner described, the advantages of durability and
great capacity are combined, the plate possessing the desirable properties of both
of the ordinary types of plate at present employed.
Dated this 22nd dos of Hohmanz 1807

page_text: I, EDWARD HEYL, of 236, Great Clowes Street, Higher Broughton, Manchester,
Electrical 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:―
The
This invention relates to improvements in connection with secondary batteries
or electrical accumulators and is intended to provide a positive electrode which
will present a large surface to the electrolyte and at the same time possess great
strength and stability. The positive electrode of a secondary battery is formed
from per-oxide or super-oxide of lead which is reduced to metallic lead.
positive electrodes are generally made in one of two types in the first of which lead
plates are employed, formed so as to give a large surface, and in the other a paste
is employed, forming a porous plate so that a much larger surface is produced.
As the capacity of the accumulator depends largely upon the surface of the lead
exposed to the action of the electrolyte, the greater the surface obtained the more
efficient is the accumulator. At the same time positive plates as hitherto con-
structed have been liable to break down after a short use. In the case of the paste
grid-plates the active material drops out of the grids and the grids themselves get
attacked by the electrolyte.
My invention provides an arrangement by which a very large surface is
obtained, while at the same time the plate is not injured in any way by rapid
charging and discharging, and the accumulator may even be completely dis-
charged without injury.
í propose to make the lead, or other metal or alloy employed for this purpose
in the form of fine threads so that the metal has an appearance somewhat similar
to that of cotton wool. The lead wool so formed is pressed into plates of the
desired size and form. The threads although pressed closely together provide a
very large surface, the plate being completely porous. A plate of this kind can be
changed into super-oxide of lead in a very rapid manner so that almost the whole
of the lead can be utilised, obtaining a very high capacity. Instead of employing
lead wool, the metal may be formed into fine strips.
A plate formed according to this method from fihe threads or strips of lead or
other material would be liable to get rapidly destroyed and drop to pieces. To
prevent this I propose to dissolve india rubber in a suitable solvent forming a
strong solution. Into this solution I introduce a quantity of chromate of lead or
other substance which will remain suspended in the solution. The lead wool is
dipped into this solution before being formed into the plates, or the plates them-
selves may be dipped into the solution after formation. The thickness of the
rubber film formed on the finely divided lead depends upon the degree of con-
centration of the solution, and the film may be increased by successive coatings.
After drying, the rubber is vulcanised. This may be done by the wet chloride of
sulphur process, or sulphur may be mixed in a dry state with the rubber solution
before dipping the plate or dissolved in carbon bisulphide or other solvent which
will mix with the rubber solution. After the rubber skin covering the lead
threads in the plate has been vulcanised, the plate is exposed to the action of an
electric current. The material, such as chromate of lead, mixed with the rubber
solution will be dissolved in the electrolyte so that the rubber covering, after this
action is completed will be filled with minute holes, allowing the lectrolyte to
penetrate and attack the fine lead threads. The lead is thus formed into super-
oxide which is supported by the rubber skin. The threads expand on being

page_text: changed into peroxide; but as the rubber also expands freely it will not allow the
material to break down.
The suspended material in the rubber may be dissolved out of the rubber skin
by treating the plate with a suitable dissolving medium which will produce the
desired effect without attacking the rubber. The rubber can thus be rendered
porous without the use of the electric current. The rubber may also be rendered
porous without adding any suspended material by heating the plate and
evaporating the solvent, the escaping gases giving the rubber a spongy texture.
To allow the plates to expand freely they are perforated by a series of holes at
a suitable distance this giving a greater surface for expansion without any danger
of the plate buckling or curving. This process may also be applied to the grids if
paste accumulators. Before the paste has been applied, the grids are covered with
spongy vulcanised rubber in the manner above described so that they are protected
from the corrosive action of the electrolyte. After the paste has been applied and
the plate formed, the latter may be covered in a similar manner with spongy
rubber, thus keeping the active material in its place and preventing the gases
developed in charging the accumulator from tearing off particles, which in the
present arrangement rapidly destroys the plate. Instead of indiarubber any suit-
able gum such as balata may be employed the method of treating the plates being
similar.
The rubber covering for the lead wines or threads (may, instead of being formed
by a solution into which the lead is dipped) he wound around the wires.
According to this method, lead wires are formed by any suitable method, of
circular, triangular, square, or other cross section, and are thus partly covered
by a thin strip of rubber wound on them in a spiral manner by a suitable machine.
Any number of these wires, (the number depending on the size of plate required)
is taken, and woven or twisted together by a rope making or other machine and
compressed into the thickness desired.
The rubber is vulcanised before or after the plate is formed, either by mixing
sulphur with the rubber in steam or by the wet process. The resulting plate is
thus of honey-comb structure, with lead wires separated and supported by vul-
canised rubber. The lead wires may be braided with the rubber strips, or each
strip may be perforated and placed on longitudinally. Grids for paste accumu-
lators may also be protected in this manner. Instead of using lead wire, strips or
grids protected by an elastic material covering the same partly, hollow wire, or
strips, or grids may be applied, the whole being fitted with an elastic core of
vulcanised or unvulcanised rubber or other suitable material.
With plates formed according to my invention from lead wool or fine lead strips
or grids, and supported in the manner described, the advantages of durability and
great capacity are combined, the plate possessing the desirable property of both of
the ordinary types of plate at present employed.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
(1) In accumulators, a positive electrode made from lead or other metal in the
form of fine threads or strips pressed closely together to form a porous plate, the
plate being afterwards dipped into rubber or like solution forming a film around
each thread, which film is afterwards treated so as to render it porous, sub-
stantially as described and for the purposes specified.
(2) In accumulators, a positive electrode made from lead or other metal in the
form of fine threads or strips pressed closely together to form a porous plate, the
plate being dipped into a rubber or like solution containing suspended material
and afterwards dissolved to render the film porous, substantially as described and
for the purposes specified.
(3) In accumulators, a positive electrode made from lead or other metal in the
form of fine threads or strips, each. thread surrounded by a film of porous rubber

page_text: or like material, the plate being provided with a series of holes giving a greater
surface for expansion, substantially as and for the purposes specified.
(4) In accumulators covering the grids of paste accumulators with spongy
vulcanised rubber or like material by dipping the grids into a solution and after-
wards covering the paste with a similar film substantially as and for the purposes
specified.
(5) In accumulators having the positive electrode formed from threads or strips
covering the said threads or strips by thin strips of rubber wound around them
and afterwards vulcanised, substantially as described and for the purposes
specified.
(6) In accumulators forming the plates from tubular wires and filling the per-
forations with rubber and afterwards vulcanising same, substantially as described
and for the purposes specified.
T: 091
of Nawambon 1907
GEO. H. RAYNER,
37, Chancery Lane, London. Agent for the Applicant.