DE1796276C

DE1796276C - Galvanic Pnmarzelle with a Lo solution electrode, a solid depolarizer and a thickened electrolyte and processes for their production

Info

Publication number: DE1796276C
Authority: DE
Inventors: Richard Dipl Chem Dr 7090 Ellwangen Huber
Original assignee: Varta Gmbh, 7090 Ellwangen
Publication date: 1971-07-01

Description

; Die Erfindung betrifft eine galvanische Prima"reelle findungsgemäßen Zelle der Elektrolyt aus dem Reak-■?,mit einer Lösungselektrode, einem festen Depolarisator tionsprodukt einer nicht oxydierenden Säure mit eUure-..._.,., _, löslichen Oxiden oder Hydroxiden von Metallen be; The invention relates to a galvanic prima "real cell according to the invention of the electrolyte from the reactor." a solution electrode, a solid depolarization product of a non-oxidizing acid with eUure -..._.,., _, soluble oxides or hydroxides of metals be

steht, die im Normalpotential gleich oder unedler sind als das Metall der Lösungselektrode, und daß der pH-Wert dieses Elektrolyten zwischen etwa -1 und + 0,7, vorzugsweise bei 0,0, liegt.
Durch Versuche wurde folgendes festgestellt:which are the same or less noble in the normal potential than the metal of the solution electrode, and that the pH of this electrolyte is between about -1 and +0.7, preferably 0.0.
The following was established through tests:

a) Die im Elektrolyten enthaltene Säure, die zunächst verhältnismäßig hoch konzentriert ist, wird durch den Zusatz der genannten säurelöslichen Oxide so weit abgestumpft, daß weder eine Korrosion der Lösungselektrode noch eine Auflösung des für den Depolarisator verwendeten Braunsteins gegeben ist. Dabei ist zu bemerken, daß die Lösungselektrode zweckmäßigerweise in der üblichen Weise zu amalgamieren ist.a) The acid contained in the electrolyte, which initially is relatively highly concentrated, is so due to the addition of the acid-soluble oxides mentioned far blunted that neither a corrosion of the solution electrode nor a dissolution of the for the Depolarizer used Braunsteins is given. It should be noted that the solution electrode is expedient to amalgamate in the usual way.

b) Trotz dieser Abstumpfung ist die Wirksamkeit des sauren Elektrolyten hinsichtlich der Leistungserhöhung der Zelle gegenüber den bekannten Zellen fast unvermindert, so daß die Leistung verdreifacht werden konnte.b) Despite this dulling, the effectiveness of the acidic electrolyte in terms of increasing performance of the cell compared to the known cells almost unchanged, so that the output tripled could be.

c) Die Amalgamierung der Lösungselektrode konnte schwächer gehalten werden als bei den bekannten Quecksilber-Zink-Zellen.c) The amalgamation of the solution electrode could be kept weaker than with the known ones Mercury-zinc cells.

d) Die Verdickerzusätze konnten ohne Schwierigkeiten mit dem Elektrolyten zu einer homogenen Masse zusammengebracht werden und entfalteten ihre Verdickertätigkeit in der gleichen Weise wie bei den üblichen nicht sauren Zellen.d) The thickener additives could be homogeneous with the electrolyte without difficulty Earth are brought together and deployed their thickening activity in the same way as with the usual non-acidic cells.

e) Die Lagerfähigkeit der Zellen erwies sich als mindestens genausogut wie bei den bekannten Zellen.e) The shelf life of the cells turned out to be at least as good as that of the known ones Cells.

'und einem verdickten Elektrolyten.'and a thickened electrolyte.

Die bekunnten Zellen dieser Art besitzen einen alkalischen oder neutralen, höchstens schwach sauren Elektrolyten, da bisher nicht die Möglichkeit gegeben war, bei einem stärker sauren Elektrolyten die Korrosion der Lösungselektrode und auch die Auflösung des Depolarisator, falls dieser aus Braunstein oder einer anderen säurelöslichen Verbindung besteht, zu verhindern. Auch war es bisher nicht möglich, stärker saure Elektrolyte mit Quellmitteln zu verdicken.The known cells of this type have one alkaline or neutral, at most weakly acidic electrolytes, as this has not yet been possible was, with a more acidic electrolyte, the corrosion of the solution electrode and also the dissolution of the To prevent depolarizer, if it consists of manganese dioxide or another acid-soluble compound. It was also not previously possible to thicken more acidic electrolytes with swelling agents.

Die Verwendung der Chloride des Magnesiums, Zinks oder Aluminiums als Bestandteile der Elektrolyte galvanischer Elemente ist seit längerem bekannt. Die pH-Werte der Lösungen dieser Salze liegen bei etwa 4 bis 5,5; beispielsweise hat eine Chlorzinklösung einen pH-Wert von etwa 4. In diesem pH-Bereich liegen auch die Elektrolyte galvanischer Zellen, die nach dem Leclanche-Prinzip aufgebaut sind. So ist auch ein ao Element bekanntgeworden, das eine Lösungselektrode aus Zink, einen festen Depolarisator und einen verdickten Elektrolyten aufweist. Letzterer enthält als Hauptbestandteil Ammonium- und Zinkchlorid sowie daneben Zinkoxid und wenig Chromtrioxid, um während der Ruhezeiten des Elementes die Korrosion der Lösungselektrode hintanzuhalten. Das pH darf keinesfalls den Wert von + 1 unterschreiten, da sonst die Schutzschicht aufgelöst wird; bevorzugt ist ein pH-Wert von etwa 4.The use of the chlorides of magnesium, zinc or aluminum as components of the electrolytes galvanic elements has been known for a long time. The pH values of the solutions of these salts are around 4 to 5.5; For example, a zinc chloride solution has a pH value of about 4. This pH range is also in this range the electrolytes of galvanic cells, which are built according to the Leclanche principle. So is an ao Element became known that a solution electrode made of zinc, a solid depolarizer and a thickened Has electrolytes. The latter contains ammonium and zinc chloride as its main ingredient in addition zinc oxide and a little chromium trioxide to prevent corrosion during the rest periods of the element to keep away from the solution electrode. The pH must never fall below the value of + 1, otherwise the Protective layer is dissolved; a pH of about 4 is preferred.

Es gab zwar in den Anfängen galvanischer Elemente Zellen mit stärker sauren Elektrolyten, wie z. B. das Bunsen- pder Grove-Element. Bei diesen Elementen wurden jedoch die Zinkelektroden im Ruhestand angegriffen, so daß Kippvorrichtungen vorgesehen werden mußten, mit deren Hilfe der Elektrolyt in Ruhepausen in Vorratsgefälie entleert wurde. Es sind auch Elemente bekanntgeworden, die Magnesium- und Graphit-F.lektrodcn enthalten, während der phosphorsaure Elektrolyt den Depolarisator in Form von gelöstem Chromtrioxid enthält und anfangs einen pH-Wert zwischen 1,8 und - 1,0 aufweist. Man hat auch bereits Akkumulatoren, das heißt wiedcraufladbare Elemente nach dem System Zink-Bleidioxid mit Schwefelsäure als Elektrolyt vorgeschlagen. Bei diesen Sekundär/eilen wird jedoch der Elektrolyt unverkleistcrt verwendet und der Depolarisator durch die Säure nicht angegriffen. Es sind daher keine besonderen Vorsorgen zu treffen, um die Reaktion des Depolarisators Aus dem Ergebnis dieser Versuche ergibt sich der besondere technische Fortschritt der galvianschen Primärzelle nach der Erfindung.In the early days there were galvanic elements Cells with more acidic electrolytes, such as B. the Bunsenpder Grove element. With these elements however, the zinc electrodes were attacked in retirement, so tilting devices are provided had to, with the help of which the electrolyte was emptied into storage vessels during breaks. There are also elements became known that contain magnesium and graphite electrodes, while phosphoric acid Electrolyte contains the depolarizer in the form of dissolved chromium trioxide and initially has a pH value between 1.8 and -1.0. You also already have accumulators, i.e. rechargeable batteries Elements based on the zinc-lead dioxide system with sulfuric acid as the electrolyte are proposed. With these Secondarily, however, the electrolyte is used unplastered and the depolarizer is used by the acid not attacked. Therefore, no special precautions need to be taken to prevent the depolarizer from responding From the result of these experiments, the special technical progress of the Galvian arises Primary cell according to the invention.

Ein weiterer Vorteil besteht darin, daß die Herstellung der Zellen nach der Erfindung auf den üblichen Maschinen erfolgen kann und somit die genannten technischen Vorteile ohne jegliche zusätzlichen Kosten herbeigeführt werden können.Another advantage is that the production of the cells according to the invention on the usual Machines can be made and thus the technical advantages mentioned without any additional costs can be brought about.

Eine vorteilhafte Ausführungsform der Erfindung besteht darin, daß der Depolarisator in an sich bekannter Weise aus Braunstein besteht. Auch bei einem Depolarisator aus Aktivkohle (Luftsauerstoffzelle) ist der Vorteil des Erfindungsgegenstandes gegeben, da durchAn advantageous embodiment of the invention consists in that the depolarizer is known per se Way is made of brownstone. This is also the case with a depolarizer made of activated carbon (air oxygen cell) Advantage of the subject matter of the invention given by

mit der Säure zu verhindern. Die Zinkelektrode wird so den sauren Elektrolyten die sonst auftretende Verbei diesen Akkumulatoren zwar im Ruhezustand ange- krustung der Aktivkohle verhindert ist.
griffen, das gelöste Zink jedoch bei der Ladung auf der Gemäß der Erfindung ist die im Elektrolyten entnegativen Elektrode wieder abgeschieden. Die Ent- haltene Säure eine nicht oxydierende starke Säure, wie wicklung galvanischer Zellen mit saurem Elektrolyten Salzsäure, Schwefelsäure oder eine Mischung dieser war deshalb erwünscht, weil es aus der Theorie be- 55 Säuren,
kiinnt ist, daß .stärker saure Elektrolyte leistungsfähigere Zellen ergeben müssen.with the acid to prevent. The zinc electrode is thus the acidic electrolyte which otherwise occurs with these accumulators, although encrustation of the activated carbon is prevented in the idle state.
attacked, but the dissolved zinc when charging on the. According to the invention, the negative electrode in the electrolyte is deposited again. The acid contained, a non-oxidizing strong acid, such as the winding of galvanic cells with acidic electrolytes, hydrochloric acid, sulfuric acid or a mixture of these, was desirable because the theory suggests that acids,
The idea is that more acidic electrolytes must result in more efficient cells.

Der Erfindung liegt die Aufgabe zugrunde, eine Zelle mit einem stärker sauren Elektrolyten so auszubilden, daß die Leistungsfähigkeit der Zelle gegenüber den be- δο kannten l'rimärzellen erhöht wird, ohne daß die vorgenannten schädlichen Folgen (Angriff auf die Lösungselektrode, Auflösung des Depolarisators) in Erscheinung treten.The invention is based on the object of designing a cell with a more acidic electrolyte in such a way that that the efficiency of the cell is increased compared to the known primary cells without the aforementioned harmful consequences (attack on the solution electrode, dissolution of the depolarizer) in appearance to step.

I.ine weitere, der Erfindung zugrunde liegende Aufgabe hesleht darin, Zellen zu bauen, deren Finlladespannungskurve möglichst waagerecht verläuft. Diese Aufauben werden dadurch gelöst, daß bei der er-Hinsichtlich der zugefügten säurelöslichen Oxide bzw. Hydroxide ist eine bevorzugte Ausführungsart gemäß der Erfindung dadurch gegeben, daß diese Oxide bzw. Hydroxide von Metallen der II. Haupt- und Nebengruppe des Periodischen Systems der Elemente oder aus Mischungen dieser gebildet sind.I. Another object on which the invention is based heslehts to build cells whose final charge voltage curve is as horizontal as possible. This Clearing up are solved by the fact that in the case of the he-Regarding the added acid-soluble oxides or hydroxides is a preferred embodiment given according to the invention in that these oxides or hydroxides of metals of the II. and subgroups of the Periodic System of the Elements or from mixtures of these.

Eine weitere besonders vorteilhafte Ausführungsform der Erfindung ist dadurch gegeben, daß die Oxide bzw. Hydroxide von Zink und/oder Calcium gebildet sind.Another particularly advantageous embodiment of the invention is given in that the Oxides or hydroxides of zinc and / or calcium are formed.

Eis hat sich als besonders zweckmäßig erwiesen, wenn die im Elektrolyten enthaltene Säure hinsichtlich ihrer Konzentration etwa 2- bis 4normal, vorzugsweiseIce has proven particularly useful when the concentration of the acid contained in the electrolyte is approximately 2 to 4 normal, preferably

Claims

utwa 3normal, und die Menge der zugesetzten säure- sonst möglioh sein würde. Nach der Erfindung istut about 3normal, and the amount of acid added would otherwise be possible. According to the invention is

löslichen Oxide bzw. Hydroxide so groß gewählt ist, dieses Verhältnis kleiner zu machen als 7:1. Mög-soluble oxides or hydroxides is chosen so large that this ratio is less than 7: 1. Possible

daß der Elektrolyt eine Restsäuro-Normalitllt von liehst ist das Verhältnis in Richtung auf den Wert 1:1that the electrolyte has a residual acid normality of the ratio towards the value 1: 1

otwti 1 aufweist. zu wählen. Die praktische Durchführung dieser er-otwti 1 has. to choose. The practical implementation of this

An exemplary embodiment for a cell according to the 3 inventive measure results in the round cell invention is characterized by a solution electrode a smaller diameter of the doll than usual, so made of amalgamated zinc, a depolarizer that between the doll and zinc cup a ratio of a manganese dioxide-soot mixture and an elec- trically large space is created,
Trolyte, which when ό to 9 parts are added contains. Wheat flour, from cells, provided that only the described characteristics of starch, cellulose derivatives or the like come into consideration as swelling agents. are turned. In particular, the invention is based on round

The normal hydrochloric acid solution can be used with the flat and flat cells.

mentioned the addition of zinc oxide to an approximately normal 15 Since it is advantageous for air oxygen cells, the

Hydrochloric acid solution blunted. Through experiments, the content of zinc ions in the cell became inherently low

found that a hydrochloric acid solution, which is to be kept from the fore, will be used in the case of such elements

in was abnormal and to which no zinc oxide was added.

had been, do not use the advantageous properties of oxide, as an additive to the acid solution,

pointed like the origin blunted by the addition. The advantages of the cell according to the invention are

borrowed more concentrated hydrochloric acid solution. One of them is particularly clear on the basis of the figure. In this figure

Electrolytes made from normal hydrochloric acid without zinc oxide- is the lateral course of the discharge voltage curve

In addition, the performance described above was not shown, where t means time and E means

increase of three times the value compared to the loading terminal voltage of the cell during discharge,

known cells, but only a much lower than 1 is comparatively the discharge voltage curve of the

Performance increase. In addition, the corrosion were common cells. 2 is the discharge voltage curve of the

and the dissolution of the manganese dioxide by no means occurs. Cells according to the invention, although the ratio

avoided, and finally the thickener was able to convert from the amount of manganese dioxide to the amount of pure hydrochloric acid

not swellable in the above-mentioned way below is approximately 7: 1, as it is when taking advantage of the

Mix. 30 usual spatial conditions given by themselves

From these comparative experiments it can be concluded that is. In contrast, 3 is the EtU charging voltage curve

that it does not depend on the concentration of the acid solution, a cell according to the invention with a ratio

but in particular on the amount of manganese dioxide according to the invention to the amount of pure hydrochloric acid,

rate matters to take advantage of the beneficial properties of the one that is less than 7: 1.

Obtain cell according to the invention. 35 The three cells tested were in their outer ones

An advantageous method of making the spatial dimensions equal to each other. The Ent electrolytes consists in the fact that, for example, zinc was charged with a relatively large current uxid carried out gradually with constant stirring of the acid solution.

Solution is added, with expediently the same. It can be seen that curve 2 is a much larger one

Salmiak is supplied early, and that afterwards this 40 shows discharge capacity as curve 1. It is also at

Electrolyte liquid, the normal room temperature of curve 2 already has a more uniform voltage

should have, the swelling agent is supplied until a rend of the discharge is given than in curve 1.

homogeneous, fillable mixture is created. In contrast, curve 3 is the discharge capacity

This method reduces the following advantages again, but is essentially aimed at: The addition of zinc oxide to a hydrochloric acid charge range, which makes the discharge voltage almost completely the same, leads to a relatively high temperature. After exhaustion of the discharge capacity, check. In contrast, the supply of then causes a sudden voltage drop. The salmiak a cooling off. Zincox ^: d and SaI- curve 3 is therefore largely similar to the discharge spanmiak added at the same time, namely in the quantities, voltage curve of a secondary cell,
as they are expedient for use in the cell. Cooling down or warming up then immediately identifies the differences,
are added to the swelling agent. This will ...
Production of the electrolyte particularly simplified and 55 claims:
facilitated. 1. Galvanic primary cell with a solution

The previously described features of the invention electrode, a fixed depolarizer and a mainly result in an increase in the performance of the cell thickened electrolytes, thereby kcnnbci Avoidance of corrosion or. Resolution records that the electrolyte, if any Appearances of the Zclien Constituents. However, it often contains 60 salmiak and is made up of the reaction product also a particularly even voltage curve of a non-oxidizing strong acid, such as salt the discharge is desired, given acid, sulfuric acid or a mixture of these if there is a certain degree of efficiency, acids, acid-soluble oxides or hydroxides can be drawn. In order to achieve this, it must consist of metals which have normal potential According to the invention, the weight ratio in the cell 65 is the same or less noble than the metal contained in the solution Braunsleinmcncnge to the electrode contained in it, and that the pH value of this electrolyte Amount of pure hydrochloric acid can be made smaller, between about -1 and -1-0.7, preferably at than it is 0.0, if the spatial conditions are used.

2. Galvanic primary cell according to claim 1, characterized in that the depolarizer in in a manner known per se consists of brownstone.

3. Galvanic primary cell according to claim 1 and 2, characterized in that the acid-soluble Oxides or hydroxides of metals of the II main group and subgroup of the periodic System of the elements or from mixtures of these are formed.

4. Galvanic primary cell according to claim 3, characterized in that the oxides or hydroxides are formed by zinc and / or calcium.

5. Galvanic primary cell according to claim 1 to 4, characterized in that the electrolyte acid contained is about 2 to 4 normal, preferably about 3 normal, in terms of its concentration and that the amount of acid-soluble oxides or hydroxides added is selected so large that the Electrolyte has a residual acid normality of about 1.

6. Galvanic cell according to claim 1 to 5, characterized by a solution electrode made of amalgamated zinc, a depolarizer made of a manganese dioxide-soot mixture and an electrolyte which is formed when about 6 to 9 parts of zinc oxide are added to 100 parts of 3-normal aqueous hydrochloric acid solution and contains the usual swelling agents and ammonia.

7. A method for producing the electrolyte for a cell according to claim 6, characterized in that that, for example, zinc oxide is gradually added to the acid solution with constant stirring is, advantageously at the same time ammonia is stirred, and that then this Electrolyte liquid, which should have normal room temperature, is added to the swelling agent until a homogeneous, fillable mixture is created.

8. Galvanic primary cell according to claim 6, characterized in that the weight ratio the amount of manganese dioxide contained in it to the amount of pure hydrochloric acid contained in it less than 7: 1, if possible up to about 1: 1.

For this 1 sheet. drawings