IMPROVEMENTS IN SECONDARY BATTERIES OR ACCUMULATORS
Year: 1883

page_text: LETTERS PATENT to Farnham Maxwell Lyte of Cotford, Oakhill Road, Putney
in the county of Surrey for an Invention of IMPROVEMENTS IN SECONDARY
BATTERIES OR ACCUMULATORS
PROVISIONAL SPECIFICATION left by the said Farnham Maxwell Lyte at
the Office of the Commissioners of Patents on the 13th July 1883.
FARNHAM MAXWELL LYTE of Cotford, Oakhill Road, Putney in the county of
Surrey "IMPROVEMENTS IN SECONDARY BATTERIES OR ACCUMULATORS
"
The object of my Invention is to increase the durability of secondary batteries
or accumulators, and it consists first in constructing the supports for the active
material of certain metallic sulphides either with or without an excess of sulphur,
and secondly in the peculiar methods hereafter described of making the electrodes
whether the supports be composed of such sulphides or not.
Certain metallic sulphides, and particularly the natural sulphides such as pyrites,
galena, or blende, when fused with an excess of sulphur, furnish a compound which,
while it is a conductor of electricity, is not attacked and oxidised by the dilute
sulphuric acid constituting the electrolytic liquid and is therefore peculiarly suited
for the construction of the supports for the spongy lead in secondary batteries.
It has been heretofore proposed to employ carbon as the support for the active
material, but, while this is effective so far as its immunity from oxidation is
concerned, its employment is objectionable in practice on account of the difficulty
experienced in making the supports of carbon and its liability to fracture, and
other inherent defects.
The active material of the electrode is in the form of a number of studs,
prisms, or bars of spongy lead, cylindrical or otherwise and having flanges, collars
or other projections, or of such shape that when embedded in a plate or support
with their ends projecting from the surface or surfaces thereof, they will be
retained securely in place. I may either cast the said compound around the root
ends of the studs, prisms or bars, or that portion of them which is to be embedded
in the supporting plate, or I may cast the plate separately and with holes in it to

page_text: receive the studs, prisms or bars. In adopting the first method I melt and cast the
said compound in sand or plaster moulds in which I have previously arranged at
proper distances apart the studs, prisms, or bars of spongy lead, the portions of said
studs, prisms or bars, which are to project from the surface of the electrode being
embedded in the sand or plaster of the mould so that on running the fused com-
pound into the mould it will surround the root ends or enlarged portions of the
studs, prisms or bars which project into the capacity of the mould and on
solidyfying will firmly retain them in place. In adopting the second method, the
supporting plates have holes cored in them, corresponding to the form of the studs
or pegs of active material which are preferably of slightly conical or pyramidal
form, or in the form of two cones set base to base so that when placed in holes in a
pair of plates secured together back to back the studs will project from the opposite
surfaces of the plates but will be prevented from falling out:
These studs, prisms or bars of spongy lead may be conveniently produced by
compressing into a mould either chloride or any insoluble salt of lead mixed, or not,
with oxide of lead, or by fusing chloride of lead or any suitable salt of lead (mixed
or not with oxide of lead) and running the same into a mould of the proper shape
and then removing the mass from the mould and reducing it by contact with
metallic zine in salt and water, or by electrolysis, to the state of coherent spongy
lead. The fused lead chloride, or other salts of lead, mixed or not with lead oxide,
and whether or no they have been agglomerated in a mould without being fused
and mixed with lead oxide, may be placed in the holes in the supporting plates
"before being reduced and be reduced therein to a state of spongy metallic lead. Or
I may take any other form of finely divided lead, for instance fine hair of metallic
lead may be made by running melted lead through a fine sieve into cold water and
compressed into the desired form. Any finely divided lead will answer provided
that it possesses the necessary coherence and presents a large surface for chemical
action.
I would have it understood that the above description of a method of making a
secondary battery is given by way of example only, for the purpose of explaining
the principle, as other methods of constructing the battery may be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed.
by the said Farnham Maxwell Lyte in the Patent Office on the 12th January
1884.
}
FARNHAM MAXWELL LYTE of Cotford Oakhill Road Putney in the County
of Surrey "IMPROVEMENTS IN SECONDARY BATTERIES OR ACCUMULATORS"
This Invention relates to secondary batteries or accumulators and consists in the
peculiar construction of the electrodes as hereafter described.
According to my invention I construct a battery in which the active material of
the electrode is in the form of a number of studs, prisms or bars of spongy lead,
cylindrical or otherwise but having flanges, collars or other projections or of such
form that when embedded in a plate or support (which may be of lead or an alloy
of lead or of other conducting material) with their ends or sides projecting from the
surface or surfaces thereof they will be retained securely in place, or instead of
having collars or projections the studs might be conical or studs of double cylindro-
conical shape truncated at the ends might be used. I may either cast the said
compound around the root ends of the studs prisms or bars, or that portion of
them which is to be embedded in the supporting plate or I may cast the plate
separately and with holes in it to receive the studs, prisms or bars in which latter
case I should combine two such plates as hereafter described.
In adopting the first method I melt and cast the said compound in sand or
plaster moulds in which I have previously arranged at proper distances apart the
studs prisms or bars of spongy lead, the portions of said studs prisms or bars which
are to project from the surface of the electrode being embedded in the sand or
plaster of the mould so that on running the fused compound into the mould it will
surround the root ends or enlarged portions of the studs prisms or bars which
project into the capacity of the mould and on solidifying will firmly retain them-in
place.
In adopting the second method, the supporting plates have holes cored in them,
corresponding to the form of the studs or pegs of active material which are
preferably of slightly conical or pyramidal form, or in the form of two cones set
base to base or with heads or collars so that when placed in holes in a pair of plates
secured together back to back the studs will project from the opposite surfaces of
the plates but will be prevented from falling out.
These studs, prisms or bars of spongy lead may be conveniently produced by
compressing into a mould either chloride or any insoluble salt of lead mixed, or not,
with oxide of lead, or by fusing chloride of lead or any suitable salt of lead (mixed
or not with oxide of lead) and running the same into a mould of the proper shape
and then removing the mass from the mould and reducing it by contact with
metallic zinc in salt and water, or by electrolysis, to the state of coberent spongy
lead. The fused lead chloride, or other salts of lead, mixed or not with lead oxide,
and whether or no they have been agglomerated in a mould without being fused
and mixed with lead oxide, may be placed in the holes in the supporting plates
before being reduced and be reduced therein to a state of spongy metallic lead:
Or I may take any other form of finely divided lead, for instance I may produce
fine hair of metallic lead by running melted lead through a fine sieve into cold
water and compress the same into the desired form. Any finely divided lead
will answer provided that it possesses the necessary coherence and presents a large
surface for chemical action.
Having described the nature of my Invention and the manner of performing the
same I would observe that I lay no claim to the use of the sulphides as specified

page_text: in my Provisional Specification as I have since found by experiment that contrary
to what I had been led to expect the acid does attack this material when the
battery is being charged and that what I claim as my invention to be protected
by the herein before in part recited Letters Patent is.-
1st The method of manufacturing an electrode of a secondary battery consisting
in melting or casting the supporting material around studs, prisms or bars of
spongy or finely divided lead having collars or projections or of such form as to
be retained in place by the supporting material, substantially as described.
2nd Constructing the electrode of a secondary battery of a pair of juxtaposed
supporting plates having studs of active material fitted in holes therein said
studs being of such form as to be retained by the plates and project from the
outer surface thereof when the latter are in place or secured together back to
back, substantially as described.
In witness whereof I the said Farnham Maxwell Lyte have hereunto set my
hand and seal this eleventh day of January in the year of our Lord One thousand
eight hundred and eighty four.
F MAXWELL-LYTE
(L.S.)