AN IMPROVEMENT IN PREPARING THE SHEET LEAD ELECTRODES OF SECONDARY BATTERIES WITH A VIEW TO THEIR RAPID " FORMATION
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A M and W
Clark of 53, Chancery Lane, in the County of Middlesex, Patent Agents, for
an Invention of AN IMPROVEMENT IN PREPARING THE SHEET LEAD
ELECTRODES OF SECONDARY BATTERIES WITH A VIEW TO THEIR RAPID
"
FORMATION Communicated to him from abroad by Gaston Planté, of
Paris, France
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Offico of the Commissioners of Patents on the 11th July 1882.
ALEXANDER MELVILLE CLARK of the firm of AM and W. Clark of
53 Chancery Lane, in the County of Middlesex Patent Agents "AN IMPROVEMENT.
IN PREPARING THE SHEET LEAD ELECTRODES OF SECONDARY BATTERIES WITH A
VIEW TO THEIR RAPID "FORMATION [Communicated to him from abroad by
Gaston Planté, of Paris, France]
This Invention relates to a process for the rapid formation of the well known
Planté secondary battery, and it consists in immersing secondary cells made of
sheets of lead, as usual, in nitric acid diluted with from once to twice its volume of
water for about twenty-four hours or longer, before submitting them to the action-
of the primary current.
The cells are then emptied, thoroughly washed, filled with water acidulated
with about 1/10 of sulphuric acid, and submitted to the action of the current from
the primary source of electricity (which may be a battery or dynamo-electric
machine) of which they are intended to accumulate and store up the energy.
By this preliminary immersion in nitric acid a small quantity of lead is of course
dissolved but the sheets suffer no sensible diminution of thickness, as, by reason of
their metallic porosity, the chemical action is not limited to the mere surfaces of
the sheets but penetrates into the interior of the metal creating new interstices and
enlarging the already existing natural pores, and consequently facilitating the
ulterior electro-chemical action produced by the primary current.
The sheets of lead intended to be employed in the construction of these.

page_text: secondary cells may be submitted to the action of the dilute nitric acid and washed,
before being rolled up or otherwise made into cells, but the process is equally
applicable to cells already constructed.
Secondary cells thus formed will, after having been submitted for a few hours to
the action of the primary current, give off a discharge current lasting for a long
period, whereas when they have not previously been attacked by the nitric acid
several weeks of electric action are required before they will give the same results.
Reversing the direction of the primary current, which is so useful in the ordinary
mode of forming secondary cells, is equally efficacious in the present case without
however being so frequently necessary.
SPECIFICATION in pursuance of the conditions of the Letters Patent, and
of an Order of the Lord Chancellor, filed by the said Alexander Melville
Clark in the Great Seal Patent Office on the 22nd March 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of
53 Chancery Lane in the County of Middlesex, Patent Agents, "AN IMPROVEMENT
IN PREPARING THE SHEET LEAD ELECTRODES OF SECONDARY BATTERIES WITH A
VIEW TO THEIR RAPID FORMATION." A communication to me from abroad by
Gaston Planté of Paris, France
This Invention relates to a process for the rapid formation of the well known
Planté secondary battery, and it consists in immersing secondary cells made of
sheets of lead (similar to those devised by Mr Gaston Planté since 1860) in nitric
acid diluted with from once to twice its volume of water for a space of about
24 hours or more before submitting them to the action of the primary current:
The cells are then emptied, thoroughly washed, filled with water acidulated with
about 1/10 of sulphuric acid and submitted to the action of the current from the
primary source of electricity (which may be a battery or dynamo-electric machine)
of which they are intended to accumulate and store up the energy. By this
preliminary immersion in nitric acid, a small quantity of lead is of course dissolved
but the thickness of the sheets suffers no sensible diminution as, by reason of their
metallic porosity, the chemical action is not limited to the mere surfaces of the
sheets of lead but penetrates into the interior of the metal, creating new interstices
and enlarging the natural pores already existing, and consequently facilitating the
ulterior electro-chemical action produced by the primary current.
The sheets of lead intended to be employed in the construction of these
secondary cells may be submitted to the action of the dilute nitric acid and washed
before being rolled up or arranged in cells, but the process is equally applicable to
cells already constructed.
Secondary cells thus formed will, after having been submitted for a few hours to
the action of the primary current, give off a discharge current lasting for a long
period, whereas when they have not previously been attacked by the nitric acid,

page_text: "
several weeks of electric action are required before they will give the same results.
Reversing the direction of the primary current which is so useful for the operation
which the said Gaston Planté described in 1872 under the name of "formation
of secondary cells, is equally efficacious in the present case without it being
necessary to so frequently effect this change.
Having described the nature of the said Invention and the manner of performing
the same, I would observe that I am aware that the use of a mixed solution of
sulphuric and nitric acids for the preparation of the surface of lead plates and for
the deposition thereon of sulphate of lead is described in the specification filed
under Letters Patent dated the 4th day of August 1882 and numbered 3710
granted to Thomas Parker and Paul Bedford Elwell, and I desire to state that
I do not claim the use of the mixed acids as therein described for either of the
purposes aforesaid," but what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is.
The use of nitric acid for the rapid formation of lead plates of secondary
batteries as above described, and for the purpose set forth.
In Witness whereof I the said Alexander Melville Clark have hereunto set
my hand and seal this twentieth day of March, A.D. 1883.
A
CLAD