Improvements in and connected with Substances to Prevent Polarisation in Electric Batteries.
Year: 1897

page_text: Date of Application, 11th Oct., 1897- Accepted, 30th Apr., 1898
COMPLETE SPECIFICATION.
Improvements in and connected with Substances to Prevent
Polarisation in Electric Batteries.
I, DR. GUSTAV PLATNER, of Witzenhausen-on-the-Werra, in the Province of
Hesse-Nassau, German Empire, Physician, 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:
-
This invention relates to improvements in substances to prevent polarisation
in galvanic batteries and has for its object the employment of chlorates for this
purpose. Chlorates alone or uncombined are not suited for the above purpose,
in view of the fact, that they do not give forth their oxygen under the conditions
existing in an electric battery. They would, therefore, be especially suited for
the object in question, if certain other bodies were added to said chlorates, which
bodies in consequence of chemical affinity or pure catalytic action would cause
the chlorates to give off their oxygen.
Chemical compounds in the first place suitable for the purpose in question,
that is to say, compounds which by chemical decomposition cause oxygen to be
given off, belong for instance salts of iron, and secondly nearly all metallic salts,
which have the quality of readily passing over into basic compounds. The
reaction is of such a character, that a part of the oxygen or halogen is given off,
or a part of the acid becomes free; so that, to give an instance, the chlorine of
the chlorides, or, the radical acid (or acid groups) of the other acids are substituted
by the hydro-oxyl group OH and therefore can be used to prevent polarisation.
Hereby in many cases various additions are necessary, which prevent the possibly
freed hydro-oxide from remaining upon the electrodes i.e. forming an insulating
layer around the electrodes, which could possibly cause the formation of double-
salts.
To such bodies of the second class which by catalytic action cause the disengage-
ment of the oxygen, of the chlorate belongs especially in the first case the peroxides
of the heavy metals, more particularly the acids of the same and their salts. These
bodies are employed for depolarisation of electric batteries; in a mixture with
chlorate probably they are not changed, but appear to serve as contact substances
1.e. substances which act only by transferring their oxygen.
I will proceed to give examples of a number of mixtures or compounds prepared
according to this principle serving for depolarisation purposes:
If for instance an iron-electrode is placed in a solution of chloride of iron, with
chlorate of potassium, the iron electrode is first acted upon, whereby chloride of
iron is formed and subsequently hydroxyde of iron is precipitated from the solution
containing a little basic chloride.
The potential difference is in this case 0,95 volt. An addition of bichromate of
potassium increases the tension to 1,2 volts and the electrode remains free from
layers of gas and hydroxyde. Should any precipitate be seen in the mixture,
the same can be brought in solution with muriatic acid whereby a small amount of
the excess quantity of the latter can advantageously act for the reason that chlorate
Din Rd17

page_text: treated with muriatic acid also disengages chlorine. A battery cell of this descrip-
tion, when muriatic acid is added from time to time, will be serviceable and will
act for a long period.
2. A zinc rod placed in any optional exciting liquid, such as for instance chloride
of zinc to which an addition of chlorate of potassium or of sodium, and per-
manganate of potassium is made, gives a tension of 1,5 volt. The permanganate
apparently undergoes hereby no change but if chlorate were not present, a
precipitate of hydrate of manganese or peroxide of the same would be immediately
obtained more especially at the electrodes.
3. In a carbon cylinder, a dry mixture of sulphate of iron, chlorate of potassium
or sodium and peroxide of manganese is tightly packed together. When placed
with zinc in a solution of chloride of ammonium a tension of 1,8-1,9 volt is
obtained. The sulphate of iron could be substituted by or for, sulphate of chromium,
the peroxide of magnesium by or for, peroxide of lead. If two of the three com-
ponents be mixed together, no noticeable action of one upon the other takes place.
If, however all three are mixed together, a chemical re-action would at once take
place. A basic iron or chromium salt would be formed, the sulphuric acid would
decompose the chloride acid, which would at once separate to chlorine and oxygen.
This action, however, takes place so gradually in the battery cell that the same
would remain constant, i.e. the action would continue without material alteration
for a considerable space of time.
The chemical action which takes place when chlorate of potassium and peroxide
of manganese is heated, or in solution with free acids, is as follows:
If free acid is present then the chlorine is also freed.
4. Tin-chloride-chlorammonium with chlorate of potassium when employed
as depolarisation substance, gradually gives off its whole contents of chlorine,
in which all the tin gradually goes over into hydroxide. The tension is 1,7 volt
and very constant. Here it is true, the salts of tin would penetrate the pores of
a diaphragm, and a diminution of the constancy of the cell would not be avoidable
for long periods together.
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. A novel composition for filling electric battery cells for depolarisation
purposes, composed of chlorates combined with the peroxides of the heavy metals,
their acids and salts, the peroxides of the heavy metals freeing the oxygen of the
chlorates by catalytic action, substantially as described.
2. A novel composition for filling electric battery cells for depolarisation
purposes, composed of chlorates, metallic salts which are capable of readily. forming
basic salts and the peroxides of the heavy metals, substantially as described.
100
J. P. BAYLY,
18, Fulham Place, London, W.,
Agent for the Applicant.
J. P. BAYLY,
18, Fulham Place, London, W.,
Agent for the Applicant.