Year: 1896

page_text: Date of Application, 9th July, 1896
Complete Specification Left, 9th Apr., 1897-Accepted, 9th July, 1897
I, HUGH FITZALIS KIRKPATRICK-PICARD of 33 Wharf Road, County of London,
Metallurgical Chemist, do hereby declare the nature of this invention to be as
follows:-
My invention has for its object the production of a current of electricity, by the
consumption of carbon in air or oxygen in a suitably arranged apparatus.
I am aware that numerous attempts have been made to make a primary battery, in
which carbon is the element consumed using (among other compounds) caustic soda
or potash in a fused state for the electrolyte but so far no method has achieved
practical importance.
In my invention I make use of the following principle. There are certain
electrolytes which are chemically acted upon by carbon at a temperature at which
certain metals do not act upon the same electrolyte. For example if litharge (Pho)
be melted in a copper crucible, the copper does not reduce the oxide of lead at a
temperature even considerably higher than its melting point. Carbon on the other
hand readily reduces it at its melting point to metallic lead forming carbonic oxide.
Now I have found that if litharge be melted in a copper crucible which is connected
by a wire to one of the terminals of a galvanometer and a piece of carbon connected
to the other terminal be placed into the molten litharge, a current of electricity is
produced, the direction in the external circuit being from the copper crucible to
the carbon, and from the carbon to the copper through the electrolyte.
Upon electrical connection being established the metallic lead is precipitated on the
copper; the lead runs down to the bottom of the copper crucible, and a blast of air
or oxygen is introduced to reoxidise the lead to litharge. In this way it is clear that
the oxygen of the air which is introduced burns the carbon through the medium of
the litharge which only acts as a carrier of oxygen.
In the simple form of battery above described there is a great waste of energy
owing to the strong local action (of a purely chemical nature) and the consequent
production of heat. It is therefore found necessary to dilute the litharge with other
compounds, as for example oxide of sodium, caustic Soda, or potash (forming
plumbates), or soda with silica forming a double silicate of Sodium and lead. It must
be understood that I do not confine myself to oxide of lead as any oxide will answer
my purpose which is decomposed more readily by the carbon than by the metal
which is used for the other pole, which may be conveniently the containing crucible,
but this is not necessary: and further the said oxide must produce a metal on the non
carbon pole which metal must be capable of oxidation by air or oxygen at the
temperature of the bath. Thus under certain conditions sodium oxide (Na,O) will
produce the desired result, but I prefer to use a mixture of two of more oxides or
oxi-salts such as Plumbates stannates silicates etc. so as to reduce the melting point.
of the bath. The temperature must be high enough to produce a reaction between

page_text: the carbon and the oxide when electrical connection is established. If desired hard
and soft carbon may be used for the two poles, in which case it is the soft carbon
which would be consumed.
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Electric Battery.
I, HUGH FITZALIS KIRKPATRICK-PICARD of 33 Wharf Road, County of London,
Metallurgical Chemist, 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 has for its object the production of a current of electricity, by the
consumption of carbon in air or oxygen in a suitably arranged apparatus.
I am aware that numerous attempts have been made to make à primary battery, in
which carbon is the element consumed using (among other compounds) caustic soda
or potash in a fused state for the electrolyte but so far no method has achieved
practical importance.
In my invention I make use of the following principle. There are certain
electrolytes which are chemically acted upon by carbon at a temperature at which
certain metals do not act upon the same electrolyte. For example if litharge (PbO)
be melted in a copper crucible, the copper does not reduce the oxide of lead at a
temperature even' considerably higher than its melting point. Carbon on the other.
hand readily reduces it at its melting point to metallic lead forming carbonic oxide.
Now I have found that if litharge be melted in a copper crucible which is connected
by a wire to one of the terminals of a galvanometer and a piece of carbon connected
to the other terminal be placed into the molten litharge, a current of electricity is
produced the direction in the external circuit being from the copper crucible to the
carbon, and from the carbon to the copper through the electrolyte.
"Upon electrical connection being established the metallic lead is precipitated on the
copper; the lead runs down to the bottom of the copper crucible, and a blast of air
or oxygen is introduced to reoxidize the lead to litharge. In this way it is clear that
the oxygen of the air which is introduced burns the carbon through the medium of
the litharge which only acts as a carrier of oxygen.
In the simple form of battery above described there is a great waste of energy
owing to the strong local action (of a purely chemical nature) and the consequent
production of heat. It is therefore found necessary to dilute the litharge with other
compounds such as with oxide of sodium or a caustic soda or potash forming in the
case of lead alkaline plumbates, or with other metallic oxides forming similar alkaline
metallic compounds; or the litharge may be mixed with soda and silica forming
double alkaline silicates. It must be understood that I do not confine myself to oxide
of lead as iny electrolyte as any oxide will answer ny purpose which is decomposed
more readily by the carbon than by the metal which is used for the other pole, which
may be conveniently the containing crucible, but this is not necessary: and further
the said oxide must produce a metal on the non carbon pole which metal inust be
capable of oxidation by air or oxygen at the temperature of the bath. Thus under
certain conditions sodium oxide (Na,O) will produce the desired result, but I prefer
to use a mixture of two or more oxides or oxi-salts such as Plumbates, Stannates,
Silicates etc. so as to reduce the melting point of the bath. The temperature must be
high enough to produce a reaction between the carbon and the oxide when electrical

page_text: connection is established. If desired hard and soft carbon may be used for the two
poles, in which case it is the soft carbon which would be consumed.
Having now 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. The production of electricity by the consumption of carbon in an electrolyte
composed of a molten metallic oxide which is decomposed more readily by the carbon
than by the metal vessel in which it is held and which forms the other element.
2. The production of electricity by the consumption of carbon in an electrolyte
composed of a molten metallic oxide such as litharge.
3. The production of electricity by the consumption of carbon in an electrolyte
such as litharge or other suitable oxide contained in a copper vessel whereby the
metallic lead is deposited on the vessel and the oxygen of the oxide converted into
carbonic acid substantially as described.
4. In the production of electricity by the consumption of carbon in an electrolyte
such as litharge the regeneration of litharge or the oxide by an air or oxygen blast.
5. The employment as the electrolyte in a battery such as described of litharge or
other oxide diluted with oxide of sodium, or with caustic soda or potash or with soda
and silica forming a double silicate for the purpose described.
6. The employment as the electrolyte in a battery such as described of litharge or
other oxide diluted with oxide of sodium, or with caustic soda or potash forming in
the case of lead alkaline plumbates, or with other metallic oxides forming similar
alkaline and metallic compounds; or with soda and silica forming double alkaline
silicates for the purpose described.
Dated this 9th day of April 1897.
BOULT & WADE,
Agents for the Applicant.