IMPROVEMENTS IN PRIMARY VOLTAIC BATTERIES
Year: 1883

page_text: LETTERS PATENT to Desmond Gerald Fitz-Gerald of Brixton in the County.
of Surrey, Electrician, and Thomas John Jones of Princes Street, Hanover
Square in the County of Middlesex for an Invention of IMPROVEMENTS IN
PRIMARY VOLTAIC BATTERIES
PROVISIONAL SPECIFICATION left by the said Desmond Gerald Fitz-Gerald
and Thomas John Jones at the Office of the Commissioners of Patents on the
16th November 1883.
DESMOND GERALD FITZ-GERALD of Brixton in the County of Surrey, Electrician,
and THOMAS JOHN JONES of Princes Street, Hanover Square, in the County of
Middlesex, Electrician, IMPROVEMENTS IN PRIMARY VOLTAIC BATTERIES."
Our Invention relates to improvements in primary voltaic batteries wherein we
employ at the negative element lead or carbon in contact with peroxide of lead
such peroxide being preferably obtained by the electrolysis of an oxide or salt of
lead, or by the conversion of spongy lead into peroxide. When carbon is employed
as the negative element, it may advantageously be in the form of small fragments
surrounding a rod or plate of the same material, the interstices between the carbon
fragments being filled with lead peroxide; or when carbon is used the lead peroxide
may be replaced by a solution of chromic acid obtained electrolytically. As the
positive element we employ lead in a highly porous condition as obtained by a
greater or less degree of compression of the metal reduced from its oxides or salts,
by chemical decomposition or by electrolysis, or by the compression of lead in
a state of minute subdivision produced by mechanical means. In certain cases
we employ in conjunction with a negative element such as above described, a
positive element of zinc or of an alloy of sodium, or of an amalgam of this metal.
When lead is reduced by electrolysis in contact with carbon fragments, we
sometimes separate the reduced metal from the carbon by a process of sifting.
As the electrolyte we use dilute sulphuric acid preferably holding in solution
a small proportion of sulphate or tartrate of ammonia

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Desmond Gerald Fitz-Gerald and Thomas John Jones in the
Patent Office on the 14th May 1884.0
DESMOND GERALD FITZGERALD of Brixton in the County of Surrey Electrician
and THOMAS JOHN JONES of Princes Street Hanover Square, in the County of
Middlesex "IMPROVEMENTS IN PRIMARY VOLTAIC BATTERIES
"
According to our invention we employ at the negative element in primary
voltaic batteries lead or carbon in contact with peroxide of lead (such peroxide
being obtained by the electrolysis of an oxide or salt of lead, or by the electrolytic
conversion of spongy lead into peroxide) in conjunction with a positive element of
porous lead obtained by the compression of lead electrolytically reduced from an
oxide or salt of the metal.
When carbon is employed at the negative element, it may advantageously be in
the form of small fragments surrounding a rod or plate of the same material, the
interstices between the carbon fragments being filled with lead peroxide; or, when
carbon is used, the lead peroxide may be replaced by a solution of chromic-acid
obtained electrolytically
As the positive element we employ lead in a highly porous condition as obtained
by a greater or less degree of compression of the metal reduced from its oxides or
salts by electrolysis. When lead is thus reduced electrolytically the operation is
facilitated by mixing the oxide or salt of lead with fragments of gas carbon, and
when this process is employed the reduced metal may be separated from the carbon
by sifting, or the mixed materials (lead and carbon) may be compressed together
and thus employed as the positive element.
As the electrolyte (when lead peroxide is used at the negative element) we use
dilute sulphuric acid preferably holding in solution a small proportion of sulphate
or tartrate of ammonia.
The following are examples of the mode in which we carry out our invention.
To take, first, the case in which lead is used as the positive element in the primary
battery-We take lead in a state of fine subdivision as obtained by the electrolytic
reduction of an oxide or salt of lead, and subject it to compression in a mould of
iron or other suitable material so as to produce a plate or hollow cylinder of the
metal which is thus obtained in a more or less porous condition according to the
degree of compression employed. The plate or cylinder thus formed serves as
the positive element of the battery, and, in virtue of its porous structure, it
becomes almost entirely converted into sulphate of lead by the action of the
battery when dilute sulphuric acid is employed as the electrolyte. For the purpose
of obtaining contact with the porous metal we embed in it a tang or strip of
sheet lead,
For the negative element we employ one of the plates (originally of porous lead
or of lead coated with an oxide of the metal) which served as the anode in the
electrolytic tank wherein the material used for making the above mentioned
positive element (viz lead in a state of fine subdivision) was obtained at the
cathode. That is to say, we employ as the negative element lead which has been
coated electrolytically with peroxide of lead.
The two elements may be arranged vertically within a cell containing dilute
sulphuric acid as the electrolyte. As it is desirable that the elements should be in
close proximity to each other, we prefer to place between them a trellis of wood or
other suitable material for the purpose of obviating accidental contact.
Taking now the case in which carbon is employed at the negative element, we
employ a plate of gas-carbon surrounded with peroxide of lead which has been

page_text: produced electrolytically in bulk. The peroxide, either abone or preferably mixed
with carbon fragments, would be held in contact with the plate of carbon by means
of a porous envelope of felt, asbestos fabric, earthenware, or other suitable material.
In the case where chromic acid is used at the negative element (in conjunction
with a positive element of porous lead) a plate of carbon is immersed in a solution
of chromic acid obtained by the electrolysis of a chromate such as bichromate of
potash.
In this case the solution of chromic acid, acidulated with sulphuric acid, constitutes
the electrolyte.
-Having described the nature of the said Invention and the manner of performing
the same we declare that what we claim as the Invention to be protected by the
herein before in part recited Letters Patent is :-
1 The construction of a primary voltaic battery as herein specified with a
negative element of lead coated electrolytically with peroxide of lead or of carbon
surrounded with peroxide of lead obtained electrolytically from an oxide or salt of
the metal, such negative element being in either case used in conjunction with a
positive element of porous lead obtained by the compression of lead electrolytically
reduced from an oxide or salt of the metal.
2nd The construction of a primary voltaic battery as herein specified with a
negative element of carbon immersed in a solution of chromic acid obtaind electro-
lytically by the decomposition of a chromate, in conjunction with a positive element
of porous lead obtained by the compression of lead electrolytically reduced from an
oxide or salt of the metal.
In witness whereof I the said Desmond Gerald FitzGerald for myself and on
behalf of the said Thomas John Jones have hereunto set my hand and seal this
fourteenth day of May A.D 1884.
TROMONT A
TIMPORTD
DESMOND G. FITZGERALD.
D. (..)