A NEW OR IMPROVED SECONDARY BATTERY
Year: 1882

page_text: LETTERS PATENT to Charles Henry Cathcart of Cressingham Grove, Sutton
in the County of Surrey and Charles Buller Granville Cole of No 17 Grace-
church Street in the City of London, for an invention of A NEW OR
IMPROVED SECONDARY BATTERY
PROVISIONAL SPECIFICATION left by the said Charles Henry Cathcart
and Charles Buller Granville Cole at the Office of the Commissioners of
Patents on the 2nd May 1882.
CHARLES HENRY CATHCART of Cressingham Grove Sutton in the County of
Surrey, and CHARLES BULLER GRANVILLE COLE of No 17 Gracechurch Street
in the City of London, "A NEW OR IMPROVED SECONDARY BATTERY"
According to our invention we construct a secondary battery as follows:-
A plate of lead is coated with oxide of lead either chemically or mechanically
and is wrapped in some suitable material such as flannel to prevent the oxide from
falling off the plate. This constitutes a negative plate. A plate of zinc is coated
electrolytically with deposited zinc and well amalgamated, this constitutes the
positive plate, if desired two of these zinc plates may be used with each negative
plate.
The above mentioned positive and negative plates are placed in a vessel con-
taining a strong solution of zinc sulphate acidulated with Sulphuric Acid to
which other similar salts such as Sulphate of Magnesium may be added if found
desirable
On a current of Electricity being passed through this combination zinc is
deposited on the zinc plate and oxygen on the oxide of lead with which it combines
to form peroxide of lead.
When the two poles of the battery are connected the reverse action takes place
and a current of Electricity results
A battery made on this system may consist of any number of plates in one
vessel or of pairs of plates in any number of vessels which plates may be connected
either for quantity or intensity

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Henry Cathcart & Charles Buller Granville Cole in the
Great Seal Patent Office on the 31st October 1882.
CHARLES HENRY CATHICART of Cressingham Grove Sutton in the County of
Surrey and CHARLES BULLER GRANVILLE COLE of No 17 Gracechurch Street in
the City of London. "A NEW OR IMPROVED SECONDARY BATTERY"
It is well known that a secondary battery may be formed by using a plate of
amalgamated zinc and amalgamated lead in a solution of sulphate of zinc, but this
combination has hitherto not been practicably applicable owing to the difficulty in
keeping the zinc plate amalgamated, without which the ordinary zinc plates are
useless for the purpose, owing to loss of electricity arising from local galvanic action
caused by impurities existing in nearly all plates of commercial zinc.
According to our present invention we obviate the above mentioned difficulties
by the following arrangements:-The Zinc plate is carefully cleaned and amal-
gamated with mercury, it is then placed in a solution of pure Zinc sulphate and
connected with the negative pole of a battery or other source of Electricity, a
current is then passed through the solution in such a way that the pure zinc shall
be deposited on the Entire surface of the Zinc plate but with a rough pitted surface.
A sufficient thickness of pure Zine having been thus obtained and care being taken
that none of the original surface of the Zinc Plate remains uncovered with pure
Zinc the plate is removed from the solution and is immediately amalgamated with
mercury, the plate is then ready for use as the positive plate. The lead plate to
be used is carefully amalgamated with mercury rubbed on to the plate with a
strong solution of caustic potash or soda, it is then washed and oxidised by immersion
in a bath of dilute sulphuric acid and passing a current of Electricity in the
ordinary manner. When sufficiently oxidised the plate is removed and is ready
for use or a further coating of oxide of lead may be applied mechanically if desired.
The plate thus formed is used as the negative plate.
The above mentioned positive and negative plates are placed in a vessel con-
taining a strong solution of pure Zinc sulphate acidulated with sulphuric acid, and
held in the desired position by a framework of some non-conducting material such
as Ebonite or wood soaked in paraffin.
On a current of electricity being passed through this combination Zinc is
deposited on the zinc plate and oxygen on the oxide of lead plate with which it
combines to form peroxide of lead; when the two poles of the battery are connected
the reverse takes place the Zine dissolving and the per oxide of lead being reduced
to oxide.
If it be desirable we use plates of any material other than Zinc on which to
deposit the pure Zinc Electrolytically and the sheets of pure Zinc formed on such
plates may be removed and used as positive plates care being taken that they have
a rough surface and are well amalgamated as previously directed.
The number of plates of Zinc and lead in each cell, the number of cells used
together, and the method of making connections &c. between the different plates
will depend upon the use for which the battery is intended.
The Zinc and lead secondary battery as described by Heury Sutton in a paper
read by him before the Royal Society on December 15th 1881 was discarded by
him owing to the necessity there would be of keeping the zine plate amalgamated
to prevent local action which seriously interfered with the efficiency of the battery.
By the method above described of preparing the Zinc plate we avoid this
difficulty the pure Zine deposited not being acted upon by the acid solution and

page_text: the roughened surface being far better adapted to receive and hold the mercury
used in amalgamating.
In this Specification we do not use the word plate in its more confined sense as
meaning a flat piece of metal but as it is used technically meaning a piece of metal
of any suitable form used as the positive or negative element in a battery.
Having thus described the nature of our invention and in what manner the
same is to be performed, we claim :-
The use for secondary batteries of a plate or surface formed of electrolytically
deposited and amalgamated pure zinc in combination with a plate or surface of
oxide of lead, both being immersed in a solution of zinc sulphate acidulated with
sulphuric acid, substantially as herein described.
In witness whereof I the said Charles Buller Granville Cole have hereunto
set my hand and seal this Thirty first day of October in the year of our
Lord One thousand eight hundred and eighty two.
CHARLES BULLER GRANVILLE COLE. (L.S.)