Improvements in the Active Material of Secondary Batteries.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Active Material of Secondary Batteries.
I, ALEXANDER SCHANSCHIEFF, of 7, Acacia Grove, West Dulwich, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
;
My invention relates to improvements in secondary batteries by means of which
certain advantages, such as considerable reduction of weight & of cost of construction
and formation as well as increase of efficiency and of rate of discharge, are obtained.
The ordinary method of preparing the active materials for secondary batteries
consists of mixing minium or other lead oxide, with dilute sulphuric acid to form a
paste. In some cases other metallic matter has been put in with the mixing process
& afterwards dissolved out, leaving, microscopically considered, air spaces. Powdered
coke, carbonisable material has been mixed with the carbon & the mixture baked
by heat. By means of my invention I render the active material of the battery
porous not by such means as aforesaid but by the method & means hereinafter
to be described. For the purposes of such description I shall describe one way
of carrying my invention into effect. I take say twenty grammes of tartaric acid,
pulverise it finely in a mortar, & add thereto ten grammes of formic acid. To
this I gradually add sixty grammes of powdered charcoal & thereafter in small
portions at a time I add one hundred grammes of sulphuric acid. With this I
subsequently incorporate one thousand grammes of minium, litharge or other oxide
of lead in small quantities at a time. During this process of mixing there is a
considerable evolution of heat & care must be exercised in consequence. I have
now obtained an active material which after being made into a paste in any of
the usual known ways, as for example by mixing with dilute sulphuric acid, may
be applied to the grids, plates or other supports as is usual. My active material
now consists of particles of lead oxide intermingled with particles of matter containing
carbon, oxygen & hydrogen. When now the plates are formed" by the usual well
known electrical process, the oxygen of the said particles is liberated & aids in the
oxidation of the positive plates of the battery, whilst the hydrogen is liberated to aid
in the reduction of the lead oxide of the negative plate, & carbon remains in a highly
porous form filling up the interstitial spaces of the active material.
This use of the oxygen & hydrogen set free from the carbonacious matter
greatly assists the formation of the plates, and thus materially cheapens one of the
most costly steps in the manufacture of commercial secondary batteries. It will be
noted also that I do not employ any external source of heat, but mix my ingredients
at the normal temperature. I have hereinbefore spoken of the employment of lead
oxides. I desire it to be understood however that I do, not limit myself to the
employment of lead oxides but that I may use metallic finely divided lead, or
indeed salts of any other metal that may be applicable. Nor do I limit myself to
the particular acids herein before mentioned, as it will be obvious to any chemist
that I may substitute any equivalent chemical agent or mixture of agents which will
give similar results. may mention acetic & citric acids in this connection.

page_text: Nor do I confine myself to the proportions of the ingredients used as it is self
evident that these may be varied without departing from the essence of my
invention.
1005
Improvements in the Active Material of Secondary Batteries.
I, ALEXANDER SCHANSCHIEFF, of 7, Acacia Grove, West Dulwich, in the County
of Surrey, Electrical Engineer, 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 :-
My invention relates to improvements in secondary batteries by means of which
certain advantages, such as considerable reduction of weight and of cost of
construction and formation as well as increase of efficiency and of rate of discharge,
are obtained. The ordinary method of preparing the active materials for secondary
batteries consists of mixing minium or other lead oxide, with dilute sulphuric acid to
form a paste. In some cases other metallic matter has been put in with the mixing
process and afterwards dissolved out, leaving microscopically considered, air spaces.
Powdered coke or carbonisable material has also been mixed with the carbon and
the mixture baked by heat. By means of my invention I render the active
material of the battery porous not by such means as aforesaid but by the method
and means hereinafter to be described.
For the purposes of such description I shall describe one way of carrying my
invention into effect. I take say twenty grammes of tartaric acid, pulverise it
finely in a mortar, and add thereto ten grammes of formic acid. To this I
gradually add sixty to eighty grammes of powdered charcoal and thereafter in
small portions at a time I add one hundred to 180 grammes of sulphuric acid. With
this I subsequently incorporate one thousand to 700 grammes of minium, litharge
or other oxide of lead in small quantities at a time. During this process of mixing
there is a considerable evolution of heat and care must be exercised in consequence.
I have now obtained an active material which after being made into a paste in any of
the usual known ways, as for example by mixing with dilute sulphuric acid, may be
applied to the grids plates or other supports as is usual.
My active material now consists of particles of lead oxide intermingled with
particles of matter containing carbon, oxygen and hydrogen. When now the plates
are "formed" by the usual well known electrical process,, the oxygen of the said
particles is liberated and aids in the oxidation of the positive plates of the battery
whilst the hydrogen is liberated to aid in the reduction of the lead oxide of the
negative plate, while carbon remains in a highly porous form filling up the interstitial
spaces of the active material.
This use of the oxygen and hydrogen set free from carbonaceous matter greatly
assists the formation of the plates, and thus materially cheapens one of the most
costly steps in the manufacture of secondary batteries. It will be noted also that I
'do not employ any external source of heat, but mix my ingredients at the normal
temperature. I have herein before spoken of the employment of lead oxides. I desire
it to be understood however that I do not limit myself to the employment of lead
oxides but that I may use metallic finely divided lead, or indeed, salts of any other metal
that may be applicable. Nor do I limit myself to the particular acids hereinbefore
mentioned, as it will be obvious to any chemist that may substitute any equivalent
chemical agent or mixture of agents which will give similar results. I may mention
acetic and citric acids in this connection.

page_text: Nor do I confine myself to the proportions of the ingredients used as it is self
evident that these may be varied without departing from the essence of my
invention.
Having how particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A process for the production of active material compound for battery elements
consisting in intimately mixing pure carbon with organic hydrocarbon acids sulphuric
acid and lead material, and then causing such a decomposition of the organic acids
by means of an electric current, that a finely porous gas absorbing conducting
substance of peroxide of lead and carbon is produced substantially as set forth.
2. A process for the production of active material compound for battery elements
consisting in intimately mixing pure carbon with tartaric acid, formic acid
sulphuric acid and lead material in or about the proportion stated and decomposing
the acids by electric current substantially as set forth.
3. The improved secondary battery plate consisting of a conductor and a highly
porous gas absorbing conducting substance consisting of lead material and carbon
made as described.