Improvements in or connected with so-called Dry" Electrolytes for Secondary Batteries.
Year: 1893

page_text: Date of Application, 17th Nov., 1893
Complete Specification Left, 17th Aug., 1894-Accepted, 16th Feb., 1895
PROVISIONAL SPECIFICATION.
"
Improvements in or connected with so-called Dry" Electrolytes
for Secondary Batteries.
J, VILLEROY CORNEY DOUBLEDAY of 37 Walbrook, in the City of London,
Accountant, do hereby declare the nature of this invention (a communication to
me from abroad by Max Sussmann of Neuruppin, Germany, Manufacturer) to be
as follows:-
The great drawback in portable secondary batteries has hitherto been that the
electrolyte had to be used in a liquid form thus causing great inconvenience from
its liability to spill and thereby causing damage to the connections and other
parts. Many attempts have been made to overcome this serious difficulty by
putting into the battery liquid dry materials of a more or less absorbent character
such as glass wool, asbestos, sand, infusorial earth and the like, but none of these
materials have answered the purpose owing to their rendering the internal
resistance of the battery so high that the latter became useless or unsuitable for
large currents.
This present invention consists in the application of paper pulp or cellulose
prepared as hereinafter described as a medium for producing a thick stiff paste
or plastic compound which when used as an electrolyte in a secondary battery
does not materially increase the internal resistance beyond that of a liquid one
and which moreover through its adhesive consistence has the advantage of
efficiently protecting the battery plates inserted therein or packed between them.
According to this invention I take paper pulp or cellulose made from wood or
other suitable material but by preference filtering paper which I scrape or
otherwise comminute into fine particles. This dry material or pulp I then boil in
diluted sulphuric acid and afterwards wash it in water until all traces of acid have
been removed. I then boil it in a dilute solution of caustic potash and again
wash it in water till all traces of that solution have been removed. Finally
I boil it in alcohol. The material when dry forms a fine powder which is then
made to absorb dilute sulphuric acid at the same time swelling out after the
manner of starch so as to form a stiff thick paste or adhesive mass. Or the
powder may be placed in the battery and the sulphuric acid solution then poured
on it.
Dated this 17th day of November 1893.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with so-called "Dry" Electrolytes
for Secondary Batteries.
I, VILLEROY CORNEY DOUBLEDAY of 37 Walbrook, in the City of London,
Accountant, do hereby declare the nature of this invention (a communication to me
from abroad by Max Sussmann of Neuruppin, Germany, Manufacturer) and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
The great drawback in portable secondary batteries has hitherto been that the

page_text: electrolyte had to be used in a liquid form thus causing great inconvenience from
its liability to spill and thereby causing damage to the connections and other parts.
Many attempts have been made to overcome this serious difficulty by putting
into the battery liquid dry materials of a more or less absorbent character such
as glass, wool, asbestos, sand, infusorial earth and the like, but none of these
materials have answered the purpose owing to their rendering the internal
resistance of the battery too high.
This present invention consists in the application of paper pulp or cellulose
prepared as hereinafter described as a medium for producing a thick stiff mass or
plastic compound which when used as an electrolyte in a secondary battery does
not materially increase the internal resistance beyond that of a liquid one and
which moreover through its adhesive consistence has the advantage of efficiently
protecting the battery plates inserted therein or packed between them, because it
effectually prevents the active material from being dislodged and falling to the
bottom thereby short circuiting the plates.
According to this invention I take paper pulp or cellulose made from wood or
other suitable fibrous material in a finely disintegrated condition, fine powdery
saw dust for instance, but by preference filtering paper which I scrape or other-
wise comminute into fine particles. This dry powdery material or pulp I then
boil for about an hour in a sulphuric acid solution of about 1 to 10, and afterwards
wash it in water until all traces of acid have been removed. I then boil it for
about one to two hours in a caustic potash solution of about 1 to 50 and again
wash it in water till all traces of that solution have been removed. Finally I
boil it in alcohol say for about half an hour or an hour.
The material when dry forms a fine powder which is then made to absorb
dilute sulphuric acid as used in storage cells so that it swells out after the manner
of starch and forms a stiff thick adhesive mass. Or the powder may be placed in
the battery and the sulphuric acid solution then poured on it.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The application and use as a medium in so called dry electrolytes for
secondary batteries of a cellulose powder made substantially as described.
2. The "dry" electrolyte for secondary batteries made as described.
Dated this 17th dev of Anost 1004
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.