IMPROVEMENTS IN SECONDARY BATTERIES OR ELECTRIC ACCUMULATORS
Year: 1882

page_text: LETTERS PATENT to Frank Clarke Hills of the Chemical Works Deptford in the
County of Kent Manufacturing Chemist for an Invention of "IMPROVEMENTS
IN SECONDARY BATTERIES OR ELECTRIC ACCUMULATORS
"
(Void by reason of the Patentee having neglected to file a Specification in
pursuance of the conditions of the Letters Patent.)
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills at the
Office of the Commissioners of Patents on the 25th September 1882.
•
FRANK CLARKE HILLS of the Chemical Works Deptford in the County of Kent
Manufacturing Chemist "IMPROVEMENTS IN SECONDARY BATTERIES OR ELECTRIC
ACCUMULATORS
"
My invention consists of the improvements hereinafter described in secondary
batteries and electric accumulators and my said improvements consist first in the
use of what I term "Feathered lead" for the elements of the said batteries. The
said feathered lead is prepared by melting it and then heating it to such a degree
that when poured in a regulated stream from a considerable height into water the
lead is brought into a very finely divided and feathery but coalescent and coherent
state. In using the said feathered lead I pack a quantity of it in fraines formed by
preference of lead or an alloy of lead and furnished with proper electrodes and I
compress the said lead in the said frames so that the feathery particles form a
porous and coherent cake. I then place the frames thus packed in cells containing
weak Sulphuric acid to form secondary batteries or electric accumulators and I
charge the batteries by means of currents of electricity in the usual way.
In some cases I paint or coat the cakes of feathered lead constituting the
aforesaid elements with oxide of lead or with a salt of lead or with a combination
of oxide and a salt of lead.
My said improvements consist further in preparing elements for secondary
batteries as hereinafter described. I add a small proportion of zinc to the lead and

page_text: feather the alloy as hereinbefore described with reference to lead aloue and I place
the feathered alloy in a vessel containing a salt of lead in solution for instance
sulphate of lead dissolved in brine. The salt of lead is thus decomposed (the acid
combining with the zinc of the alloy) and finely divided lead is precipitated into
the interstices of the feathered lead. I then wash the mixture of feathered lead and
precipitated lead free from brine and press it into cakes and use the said cakes as
elements for secondary batteries or electric accumulators as herein before described
with reference to feathered lead alone.
My said improvements consist further in forming elements for use in secondary
batteries or electric accumulators as hereinafter described I take long ribbons of
very thin lead say about one quarter of an inch or three eighths of an inch in
breadth and coil or roll them up like the main spring of a clock or watch but so
loosely that when placed in acid to form a battery the acid may permeate between
the coils and I encircle the coiled ribbons of lead with rings formed preferably of
lead or an alloy of lead and furnished with projections for electrodes which rings
form frames for containing the coiled ribbons. The coils of the said ribbons may
be fused together here and there with the blow pipe or they may be connected at
intervals with solder to keep them stiff.
In some cases before coiling the said ribbons of lead I paint. or coat them with
a composition consisting of oxide of lead or oxide and sulphate of lead mixed with
water to a suitable consistence. Or I wind between the coils of lead tape or
ribbon of any suitable material soaked or charged with the said composition.
In order to make the said composition more porous and absorbent I in some cases
I mix with it fine saw dust or peat or coke or other like matter.
. Or I mix with the said composition sulphate of soda or any other suitable
matter which is capable of being dissolved out after the composition has been
applied to the lead.
For larger elements I use thicker ribbons of lead and coil them so that wider
spaces shall be left between the coils and I pack the said spaces with oxide of lead
or with oxide and sulphate of lead or other suitable material.
I prefer to perforate or indent or flute the thicker ribbons of lead before coiling
them