Improvements in Active Material for Secondary Battery Plates.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Active Material for Secondary Battery Plates.
We, THE SUSSMANN ELECTRIC MINERS LAMP COMPANY LIMITED, of 37 Walbrook,
and SIGMUND ADOLF ROSENTHAL, of 5 Christopher Street, Finsbury Square,
Electrician, both in the City of London, do hereby declare the nature of this
invention to be as follows:-
-
The "active material" or composition made according to this Invention, and
used in connection with any suitable lead conductor to form a "plate," is very
hard and porous, while firmly adhering to the conductor.
The material used for making up the "plate" is lead oxide in the condition
of a very fine powder. This material is intimately mixed with a thin solution
of indiarubber, to which is added a solution of sulphate of ammonium, so as to form
a stiff paste, and to this may be added, if desired, a small quantity of suitable
powdered inert material, such as asbestos, slag wool, or the like, say about five
per cent. by bulk.
The composition or paste is then applied to the lead conductor under compression.
A suitable proportion of the rubber solution and the sulphate of ammonium
solution is about one to eight and one to four respectively to the weight of the
cxide of lead. When the plates are dry they are ready for being "formed" into
positives and negatives in the usual way.
Dated this 1st day of October 1896.
JENSEN & SON,
77 Chancery Lane London W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Active Material for Secondary Battery Plates.
We, THE SUSSMANN ELECTRIC MINERS LAMP COMPANY LIMITED of 37 Walbrook,
and SIGMUND ADOLF ROSENTHAL, of 5 Christopher Street, Finsbury Square,
Electrician, both in the City of London, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
The "active material" or composition made according to this invention, and
used in connection with any suitable lead conductor to form a "plate," is very
hard and porous, while firmly adhering to the conductor.
The material used for making up the "plate" is lead oxide in the condition
of a very fine powder. This material is intimately mixed with a thin solution
of india rubber, to which is added a solution of sulphate of ammonium so as to form
a stiff paste, and to this may be added, if desired, a small quantity of suitable
D
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page_text: powdered inert material, such as asbestos, slag wool, or the like, say about five
per cent. by bulk.
The composition or paste is then applied to the lead conductor under compression.
A suitable proportion of the rubber solution and the sulphate of ammonium
solution is about one to eight and one to four respectively to the weight of the
oxide of lead: When the plates are dry they are ready for being "formed" into
positives and negatives in the usual way.
The rubber solution contains only at most two per cent, of rubber and is there-
fore not a binding material. But it fulfils two other purposes iz. in the first place
it prevents the mass from hardening too quickly by reason of the sulphate of
ammonium acting upon the lead oxide so that dealing with large masses of the
material or upon a manufacturing scale would be all but impossible, and in the
second place the rubber solution has the effect of rendering the material porous
in the plate because while the residue of strong rubber solution is all but
unaffected by diluted sulphuric acid we have found that the residue of a very thin
rubber solution which remains in the plate in the form of a very thin coating or
film enveloping each particle of lead oxide, in the course of some time becomes
dissolved by the electrolyte so that the plate then contains no rubber, but has
become more porous, as evidenced by a decreased resistance and an increased
capacity.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
· Active material, for application to a lead conductor to form a secondary battery
plate, consisting of a finely powdered lead oxide made into a stiff paste by intimate
mixture with a thin india-rubber solution, sulphate of ammonium solution, and,
if desired, powdered inert material; substantially as described.
Dated this First day of July 1807
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.