An Improvement in Carbon Electrodes.
Year: 1892

page_text: Date of Application, 24th Sept., 1892
Complete Specification Left, 23rd June, 1893-Accepted, 9th Sept., 1893
PROVISIONAL SPECIFICATION.
An Improvement in Carbon Electrodes.
HARRY THEODORE BARNETT M.I.E.E. 14 Narcissus Road London N.W.
do hereby declare the nature of this invention to be as follows:-
My invention relates to carbon electrodes for use in electric batteries or for
electrolysis & has for its objects (1) To provide a greater surface for a given space
occupied than has been hitherto obtainable (2) To present a great number of
filamentary points to the electrolyte. For this purpose I devise that the carbon be
in the form of a number of fine short filaments in contact with & outstanding from
a suitable carbonaceous or metallic conducting support.
Dated this 23rd day of September 1892.
HARRY THEODORE BARNETT.
COMPLETE SPECIFICATION.
An Improvement in Carbon Electrodes.
HARRY THEODORE BARNETT (Mem. Inst. Elec. Eugrs.) 14 Narcissus Road
West Hampstead London N.W. 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 carbon electrodes for use in electric batteries or for
electrolysis & has for its objects-
I. To provide a greater surface for a given space occupied than has been
hitherto obtainable.
II. To present a great number of filamentary points to the electrolyte.
For this purpose
devise that the carbon be in the form of a number of fine
short filaments in contact with and outstanding from a suitable carbonaceous or
metallic conducting support.
The said filaments (or "pile") may be produced from any suitable carbonisable
The said
material, such for instance as cotton, flax, jute, wood, celluloid, bass, etc.
filamentary substances may be carbonised and used in the form in which they
originally occur or after having been either sub-divided and separated or combined
and agglomerated, according to the thickness which it is desired the resulting
or more varieties of such
filament shall be, they may each consist of one
carbonisable fibre or they may be formed from some plastic substance or mixture.
The said filaments may be carbonised before, after or during their attachment to
the conducting support.
They may undergo any suitable mechanical, chemical or other treatment either
before, after or during carbonisation-such treatment usually is for the purpose of
increasing the toughness, conductivity, or selective gaseous affinity or the reverse
of the material.
The conducting support may consist of any metal convenient, or of carbon, it
may be of any desired shape, or of any suitable structure, for instance, solid,
laminated or filamentary.
The filaments or pile may be attached to the conducting support by various

page_text: methods either before, after, or during the carbonisation of the said pile or the said
conducting support. Among these methods may be instanced :-

page_text: The filaments may with advantage extend through the whole space occupied by
the depolarizing solution, as there being no liberation of gas the said depolarizer
does not, of its own accord, circulate freely.
IV. AS AN ELEMENT OF EITHER SIGN FOR USE IN GAS OR GAS METAL
BATTERIES.
Surface being of premier importance the filaments may be of the greatest
convenient length and fineness, and should be as close in pile as is consistent with a
ready permeability.
The filaments should preferably be produced from such material or should
undergo such treatment as shall ensure their possessing the greatest possible
selective gaseous affinity in the desired direction; in some cases, owing to its
distinctive selective action, animal charcoal may be used.
If the whole "pile" is to be immersed in the gas, the conducting support being
the liquid contact, it is convenient to arrange the latter so that its structure is
filamentary textile thus being readily permeable by liquid, and consequently of low
electrical (diaphragm) resistance-as for instance, in carbonized velveteen whose
pile is in gas and whose backing is in contact with the electrolyte the electric
current produced on the surface of the pile would have a ready passage through
the liquid in the interstices of the "backing -(the filamentary textile conducting
support) to or from the opposing electrode.
""
As storage battery elements the character of the electrodes must vary with the
nature of the substance to be used upon or in conjunction with them and also with
the current density at which they are to be worked-regarding the latter point-
the length, thickness and closeness of the filaments may be decided upon the lines
indicated in paragraphs 1, 2 and 3.
VI. In electrolysis the conditions may vary so much that it is not possible for
these remarks to cover the whole field, but as a negative element or cathode in the
decomposition of water the conditions being practically similar to those in
paragraph I the same class of carbon as therein mentioned may be used.
To definitely detail a method of producing one form of my electrodes :-Having
obtained some round electric light carbon rods (preferably of dull surface), paste,
velveteen, and charcoal dust-lightly paste the carbon rods and dry them: well
paste the back of the velveteen, rubbing the paste vigorously into the fabric, then
dry; cut the dried pasted velveteen in strips and after again pasting, twist the
strips tightly round the carbon rods so as to just cover the same; after drying
slowly and thoroughly, finish by carbonizing in the crucible chamber of a muffle
gas furnace, the carbons during this carbonization being preferably packed
thoroughly in charcoal dust.
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 :-
CLAIM.
HARRY THEODORE BARNETT.