IMPROVEMENTS IN SECONDARY BATTERIES
Year: 1882

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PROVISIONAL SPECIFICATION left by Desmond Gerald Fitz Gerald and
Charles Henry Walker Biggs and William Worby Beaumont at the Office of
the Commissioners of Patents on the 3rd January 1882.
DESMOND GERALD FITZ GERALD of Brixton in the County of Surrey, and
CHARLES HENRY WALKER BIGGS and WILLIAM WORBY BEAUMONT both of the
Strand in the County of Middlesex. "IMPROVEMENTS IN SECONDARY BATTERIES."
This Invention relates to the improvement of secondary electrical batteries.
According to one part of our Invention we obtain electrodes having an increased
surface or porosity by utilising what is known as local action occurring between
lead and a metal electro-negative to lead. We obtain electrodes by depositing on
or in plates of lead or of lead alloy by chemical, electro-chemical or mechanical
means, a metal electro-negative to lead such metal being in most cases subsequently
removed preferably by making the plate an anode in a solution which does not
form a soluble salt of lead. As an example we may place plates of lead or any
suitable alloy containing lead in a solution of sulphate of copper slightly
acidulated with nitric acid and thus produce a deposit of copper on the surface of
the plate. Or by electro-deposition we deposit simultaneously or alternately lead
and a metal electro-negative to lead. The plate after such treatment is immersed
as an anode in dilute sulphuric acid until the copper or other metal becomes
wholly dissolved and the plate becomes covered with a coating of peroxide of lead.
Or we may mix finely divided copper such as copper filings with molten lead, or
we immerse sheets of copper gauze into molten lead or by mechanical means we
force lead into the interstices of copper gauze or the copper or other electro-
negative metal to lead into the plate of lead. The copper is removed as above
described. Previously to the deposition process we may perforate, corrugate or by
other means increase the surface of the plate, as described in our Provisional
Specification No. 5338, A.D. 1881.
Or we may coat the surface of a plate of lead with a paste composed of a salt
of lead preferably constituted with an organic acid such paste also preferably
containing acid in a free state. The plate is then heated and the salt decomposed.
Or we may obtain our electrodes by using a solution of a salt of lead preferably
constituted by an organic acid with such acid in excess and cause the solution in a

page_text: finely divided shower to be distributed over the surface of the plate, preferably
whilst the plate is at a high temperature. Or we cast plates of lead in moulds or
matrices constituted by a salt of lead in a condition of powder preferably moist, or
in a mixture of such powder with other suitable materials.
Further we may prepare our electrodes by blowing into molten lead, air or air
charged with other materials in a somewhat similar manner to that by which air
is blown into the metal in a Bessemer converter, or we may place at the bottom of
a vessel to contain molten lead, an oxide of lead or a salt of lead preferably such as
will become decomposed at the temperature of molten lead the object of both
modes being to obtain porous lead containing an oxide or other compound of the
metal in admixture, the latter method being somewhat analogous to that used in
the "Heaton process for making steel.
Another part of our Invention consists in the use as an electrolyte of a solution
of plumbic sulphate in ammonic sulphate or other menstruum which does not
prevent the forination of peroxide of lead at the anode.