Improved Secondary or Storage Battery.
Year: 1899

page_text: Date of Application, 26th July, 1899-Accepted, 4th Nov., 1899
Improved Secondary or Storage Battery.
I, TITUS DE MICHALOWSKY, of Cracow, in the Empire of Austria, Electrician,
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:—
The endeavour to replace the heavy lead storage batteries by batteries of lighter
material has led to the discovery of the alkali-zinc battery.
By the use of zinc in place of the negative plate of spongy lead the negative
electrode becomes three times as light as if made of lead; but hitherto the
requirement of a suitable depolarizator as a substitute for the plate of peroxide
of lead remains unsatisfied. The fact that the alkali-zinc batteries have been
known for nearly twenty years without having been able to replace the lead
batteries in spite of the most diligent efforts, serves as a proof that an actually
suitable material for the positive electrode has not hitherto been discovered.
Efforts in this direction have not been wanting and up to now almost every
existing metallic oxide (not excepting aluminium and manganese oxides) have
been proposed as depolarizators for this purpose.
As an example of these inventions may be cited the German Patent No. 38383
of Alfred Dun of Frankfort a/M.
In this patent oxides of copper, cobalt, nickel, bismuth, manganese and others
have been used, evidently, however, without any indication that the inventor
had made a trial of the effect of these bodies, because had he done so he would
at once have recognised that only one of these oxides distinguishes itself from the
others in every respect by its distinctive and valuable property; this is oxido
of nickel Ni, O. Further throughout the electro-chemical literature published
up to date, no indication of its action is to be found and yet nevertheless the fact
that it is the only one amongst all hitherto known metallic oxides, which is formed
from nickel sub-oxide with absorption of heat and is consequently an endothermic
compound, should have attracted attention. For such a body will if it be used
as depolarizator render possible the complete transformation of the heat of oxida-
tion of the zinc into electric energy, whilst in the case of all other depolarizators
which are of exothermic origin a large proportion of the heat of oxidation of the
zinc is wasted in the reduction of the depolarizator.
According to the annroximate formula according to Thomson
of the combination,
In which E represents the electromotive force
IF the heat grade,
The
the quantity of the valency.
n
electromotive
force of the combination zinc-(soda or potash solution)-nickel oxide will be
calculated at 1'84 volts, because the negative heat formation of the nickel oxide
is added on the discharge to the heat of combination of the zine hydroxide. An
experimental 1'85 volts tension has been obtained with this element which is
wonderfully near approximation to the theory.

page_text: Further experiments have shewn that nickel oxide if it adhere to a positive
electrode in the proper manner, will conduct very well and give thoroughly con-
stant current. The discovery of both properties of nickel oxide namely that of
the high tension produced by it when opposed to zinc in alkaline solution, as well
as good conductivity makes the nickel oxide a specially valuable depolarizator
from a technical point of view above other possible substances, and one which is
suitable to render the zinc battery preferable to the lead battery in all cases where
a light weight is of importance.
The following calculation renders this clear. In the case of peroxide of lead
there are for every 16 parts by weight of available oxygen 223 parts of lead
oxide which represent a dead weight. In the case of copper oxide batteries
10 parts by weight of oxygen represent 126 parts of copper, consequently the dead
weight is here reduced by less than one-half but on the other hand the tension
is reduced to 085 volt or by more than one half. So that the capacity calculated
in Watt-hours per unit of weight of the positive electrode is less in the copper-
zinc battery than in the lead battery. As, however, in consequence of the use of
zinc the negative electrode is three times lighter than with lead batteries, the
double capacity of the alkaline battery is somewhat although very little greater
than that of the lead battery.
With the nickel oxide battery 16 parts by weight of oxygen
require 148 parts by weight of nickel oxide, in which, however, the
tension equals 1.85 volt or practically equal to the tension of the lead
battery. The nickel oxide battery is consequently double the capacity of the copper
oxide battery, and as this latter is itself lighter than the lead battery, it may be
assumed that the nickel oxide battery is from two to three times lighter than
the lead battery. Further experiment has shown that the depolarizator, even when
it is a good conductor, must be in thoroughly intimate contact with the conducting
support the simple surrounding of the positive electrode with a paste of the
depolarizator in question as set forth in the already cited German Patent
No. 38383 will not produce a satisfactory effect.
The method of construction usual with lead only effects the purpose imper-
fectly with nickel both on account of its power of resistance to chemical re-actions.
as also on account of its extreme hardness which prevents the cohering of nickel
powder or nickel sponge by pressure or by its own weight. Moulding according
to the Plante process gives no satisfactory result, because the resistance of the
nickel to nascent oxygen at ordinary temperatures prevents any penetration into
the interior. Even if very porous nickel metal be made use of the surface thereof
covers itself with a very thin layer of oxide and even the raising of the temperature
to 100 degrees Centigrade causes no alteration.
If we operate in non-alkaline solutions it is much easier to produce an oxide.
covering, but this has no coherence, because at the same time nickel is dissolved
and therefore there is wanting a rigid metal frame which should be between
the particles of oxide. By the oxidation by chemical reagents in aqueous solu-
tions such for instance as the hypochlorites of the alkalies, nickel oxide is obtained
which, however, is also not supported and therefore lies loose upon the plate. The
oxidizing of the nickel by means of heat in the presence of air as is done in the
case of electrodes of copper oxides, will not give the required result with nickel,
because at a low heat nickel is not oxidized at all and on the other hand on heating
it strongly nickel suboxide is formed. This latter moreover is only converted into
nickel oxide on heating to between 350 and 600 degrees Centigrade, provided
it has not been too strongly heated which cannot be the case here. On the other
hand it is possible to effect the oxidation of the nickel to the state of oxide if it
be heated not in atmospheric air, but in pure oxygen. Compressed air will have
the same effect, because it is possible in it to make the pressure of the oxygen
equal to that of the pure oxygen. Further gases containing oxygen such as the
oxides of nitrogen and so forth, may be made use of and the action of all these
gases is increased by compression. But it is not by the use of ordinary oxygen,

page_text: but rather by the use of nascent oxygen at a temperature exceeding 300 degrees
Centigrade that a good oxidation of the metal takes place. Because here also the
oxidation penetrates from the surface inwards and the untouched metal serves as
the carrier of the positive matters, and provides a good conductivity and adherence
of the whole. Nascent oxygen may be obtained by heating nickel with oxidizing
re-agents which part with their oxygen at temperatures between 300 degrees and
600 degrees, such as nitrates, chlorates and so forth. The nitrate of ammonium
has been found specially suitable, because this salt leaves no residue on heating.
Porous nickel is saturated with the melted salt and is then gradually heated.
After repeated operations all the pores of the nickel are filled through and
through with oxide in a firm compact condition. Finally the metal can be
oxidized with nascent hydrogen by making use of nickel as the anode in molten
electrolytes containing oxygen at a temperature between 300 degrees and 600
degrees whereby also a firm and compact coating of oxide is obtained.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is: -
Process for the construction of alkaline zinc collecting batteries with nickel
oxide (Ni, O) as the depolarizator, characterized by the arrangement that the
nickel serving as the positive electrode is covered with a firmly adherent con-
ducting coating of nickel oxide either by heating it in pure oxygen or in gases
containing oxygen (or gaseous mixtures) under ordinary or high pressure at a
temperature above 300 degrees and below a red heat, or by treating the metallic
nickel with oxidizing agents such as nitrate of ammonium, chlorates and so forth
within the same limits of temperature, or finally by using metallic nickel as the
anode in molten electrolytes containing oxygen within the above-mentioned limits
of temperature.
18 T 1
1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.