Improvements in Secondary Batteries.
Year: 1895

page_text: Date of Application, 24th Jan., 1895
Complete Specification Left, 12th Nov., 1895-Accepted, 14th Dec., 1895
°
PROVISIONAL SPECIFICATION.
..Improvements in Secondary Batteries.
We CAMILLE ALPHONSE FAURE of 37 Avenue de la Republique Paris in the
Republic of France Electrician and FRANK KING of 4 Great Winchester Street
in the City of London Engineer do hereby declare the nature of this invention to
be as follows:-
Our invention relates to secondary batteries and provides means whereby the
active material is more effectively retained in position the gradual falling away of
the same which is the result of use being prevented or greatly. retarded.
It is well known that the capacity per unit weight of secondary batteries is
adversely affected by the very large proportion which the conductor or support
bears to the active material.
Our present invention is more particularly applicable to secondary batteries in
which a large amount of active. material is held up to, or against, a comparatively
light conducting plate or support by some extraneous means, hitherto consisting of
a perforated sheet, or envelope of celluloid, ebonite or other sufficiently acid
resisting non-conducting material in contact with the active material.
According to our invention we take a suitable form of light support to which
the active material is attached or applied. The, plate so constructed is; surrounded
or covered with a thin, layer of silicated asbestos fibre; cloth; or paper, and upon
or around the plate so covered. we place a perforated envelope or cover or sheet.or
sheets of celluloid, ebonite, or. other, sufficiently acid resisting non-conducting
material, the whole forming an electrode completely covered with a perforated
insulating envelope or cover the active material being, prevented from falling
through the perforations.of the said envelope or cover by the silicated: asbestos,
applied as aforesaid.
Deted this 24th day of January 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
..Improvements in Secondary Batteries.
We, CAMILLE "ALPHONSE FAURE, of 37 Avenue de la, Republique, Paris,
in the Republic of France, Electrician, and FRANK KING of 4 Great Winchester
Street, in the City of London,, 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:-
Our, invention relates to secondary batteries and provides efficient, durable, and
economical means whereby the active material is more effectively retained in
position than hitherto, the gradual falling away of the said active material which
is the result of use, being prevented, or greatly retarded.
...It is well known that the capacity per unit weight of secondary .batteries is
adversely affected by the very large proportion which the conductor, or support.
bears to the active material.

page_text: Our present invention is more, particularly applicable to secondary batteries in
which a large amount of active material is held up to, or against, a comparatively
light-conducting plate, or support, by some extraneous means, hitherto, usually,
consisting of an acid resisting non-conducting substance, such as a perforated sheet,
or envelope, of celluloid, paper, or ebonite, in contact with the active material, the
said acid-resisting non-conducting substance being of such a nature as to be
subject to rapid disintegration, or such as could not be applied with sufficient
facility to render it practically available.
We overcome these objections by providing the electrode with a duplex
retaining cover, or envelope, the inner member of which consists of silicated
asbestos. This cover, or envelope, is not only very easily and economically applied
in practice, but is also not injured by the peroxide of lead, or by the acid
electrolyte of the battery, and therefore adds very materially to the durability of
the battery..
"
According to our invention we take any suitable form of light support to which
the active material, (or material to be rendered, or to become, active.) is attached,.
or applied. The plate is then surrounded, or covered, with a thin layer of
silicated asbestos, which is not liable to be injured by the peroxide of lead, the
said material being in the form of a sheet, or sheets, of asbestos fabric, (such as cloth,
paper, or cardboard), and upon, or around, the plate so covered, we place a
perforated envelope, or cover, or sheet, or sheets, of perforated celluloid, ebonite,
or other sufficiently acid resisting, non-conducting, material, the whole forming an
electrode, covered with a perforated insulating envelope, or cover, the active
material being prevented from falling through the perforations of the said envelope,
or cover, by the silicated asbestos, applied as aforesaid, the said silicated asbestos
preventing the perforated cover from coming into contact with the peroxide of lead
of the plate. The method by which we prepare. the silicated asbestos fabric is as
follows: We take an asbestos fabric such as a sheet of ordinary commercial
asbestos paper, and dip it into a five per cent. solution in water of silicate of soda.
We then hang the sheet to dry in a current of air, and the effect of the carbonic
acid contained in the air is, as is well known, to set free the silica, the carbonic
acid combining with the soda to form soluble carbonate of soda. The fibres of
asbestos thus become covered with a coating of precipitated and adherent silica
which protects the binding, or agglomerating, material used in the manufacture of
the asbestos fabric, whilst still leaving the sheet, or sheets, so treated, porous for
the penetration of the exciting liquid of the battery, the carbonate of soda, formed,
leaving the silicated asbestos when it is placed in the battery. We find that by
repeating this process four times with a solution of silicate of soda of the above
strength, the fibres are sufficiently coated with silica, but the material remains
sufficiently porous. If the strength of solution be varied, or if the texture of the
paper be more close than is usual with ordinary commercial asbestos paper, care
must be taken in repeating the silicating operation, to stop short of the point at
which the deposition of the silica would clog the pores of the material and destroy
its porosity, as, if the pores be completely filled with silica, the exciting liquid
would not be able to penetrate. Instead of reducing the silica by means of
carbonic acid we may use any other suitable acid, as is well known to chemists.
.
The accompanying drawing shews in transverse section, partly in elevation, an
electrode, or plate, provided with our invention. A, is a conducting support, B, the
active material, C, is the silicated asbestos, and D, is the perforated envelope, or
cover, of celluloid, ebonite, or the like, which is prevented by the silicated
asbestos C, from coming into contact with the peroxide of lead of the electrode.
The coverings may be secured in any convenient way; for instance, the envelope,
or cover, D, may be cemented, or bound, in place so that it retains the silicated
asbestos C, in position. It is shewn as being bound at the top by cord d, which
may be of asbestos, or silicated asbestos, for example.
We are aware that it has been heretofore proposed to use glass-wool for the
purpose for which we employ our silicated asbestos fabric, but a material such as

page_text: glass-wool is too open to prevent the peroxide of lead from coming into contact
with the perforated envelope which is the object of our invention.
Having now particularly described and ascertained the nature of our said inven--
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In, or for, secondary batteries, the use of as heet of silicated asbestos fabric,.
such as is herein before described, in combination with perforated celluloid, ebonite,
or other sufficiently acid resisting material for retaining the active material in place.
as above set forth.
2. An electrode for secondary batteries having the active material covered with,
and retained by, a sheet of silicated asbestos fabric, such as is herein before
described, in combination with an envelope of perforated celluloid, ebonite, or other
sufficiently acid resisting material.
Deted this 6th day of November 1895.
JOHNSONS & WILLCOX,.
Agents.