US1518637A - Dry cell - Google Patents

Description

H. DE OLANETA DRY CELL Original Filed Feb. 24, 1920 -Oriigihail application filed February I I i 5 a, 1e20.-, jseria N0..378,456.W

Pat'ented Dec.'9,' 1924.

-- connnoriour- Be it known that I, -HA'RoLo-"nn OLAN'ET'A,

of New Haven, county'oflNew Hayen',- State of Connecticut, have invented:. certai1fjnew and useful Improvements -in Dr-y Cellsl, of

eXac-tdescription, y e e This "invention relatesto galvan and-more particularly to dry cells.

which the following is a full, clear,-

The present 'applicationis a division f my application Serial No, 360,553, filed with to increase the longevity of the cell, bothcell is-finally put mto use, the zmc cup 1s and paste.

ruary 24th, 192O, an d -per tains more espe-L.

cially to the cellper Se.

In dry cells ofwthe type now foundon .the market in large numbers; and especially those-used forpocket flash lights or hand lamps. the. zinc electrode is in the form of a cup in whichare contained a carbon" electrode with a surrounding body of depolarizing material, and an exciting past'e interpo'sed between the "depolarizing material and the side Wall of the-cup. The depolarizing material usually, consists of a mixture-of manganese dioxid and carbon which is formed into a block or. cartridgeabout the carbon electrode and is contained Within like.

In the manufacture cells ofthis typ {p reason OfdlfifilGIlCGS 1n the molecular structhe paste When placed in the'cell ordinaril contains a solutionof ammqnium -chlori which is the principal exc tlngj agentg and a paste 'moist. J The depolarizing mixture, Conand carbon (graphite), is usually moistened a solution containing ammonium chlorid and zinc 'chlorid, so as to facilitate the passage of the ions from. one electrodeto the other through the depolarizing body Some of the objects of the invention are good service capacity; and to improve the bell in otherrespects. Y c

To these and other ends, theli'nvention consists in the novel features and procedure to be hereinafter described and claimed.

I sisting of finely divided manganese dioxidvon top of apaperf washer 8.

provided with the usual contact packing and shipping. when they-leave the factory it takes some U ITED- ST -res- PATENT OFFICE.

HaizoLi) n5 misses} .nnw nhvgis boiinncricu'r, Assrsnon ro wmortns'r'nn .REPEATING nR sooMPANgpn mvnn, coNnnc'rIcu T, A conPoRA'rIoN or -adry cell, constructed in accordance with the inve'ntion. 1

in any suitable manner as by a pitch seal 7 electrode. is @1 Cells made up in the usualf'way, withan ammonium-chloride-containing paste in direct contact with the zinc, are apt to deteriorate considerably beforethey are placed in use, owingto the fact that, due to'localaction, the ammonium chlorid commences its attack on the zinc assoon as the parts I an envelope .or bag of cheese cloth-"or the of the'cell are put together. Local action ji sfset up, for example, as aresult of the resence ofzimpurities in the zinc, or by ture'jof the same at different parts of the cup.- Under present conditions of manufacture and distribution, there is usually a considerable. interval between the time when {The cell selected for illustration'comprises i the usual zinc cup, ,1,,-cons'titut-ingthe posi tive electrode; The "negative carbon elec-. trode 2 has tam'ped about" it a block or cart'ridge 3 of a suitable depolarizing mix, re-

-.fe rredt'o in greater-detail hereinafter; and

interposed between the side Wall of the cup jandthejdepolarizing material is a paste 4.. The depolarizingcartridgefis usually contained in abag or envelope 5 ofcheese cloth or-lithe, like. ,It iscentered in the cup at the bottoma suitable centering Washer 6., At the topof the-cell, the latter. issealed, Y

The carbon the cell is first assembled and the time when reaches the consumer for use. It is not uncommon for. the cells toremam m the factoryia Week or longer,-ow1ng to delays Furthermore,

time for them to reach the retailer, and, of

course, they may remain on the shelf of the retailer fora long period before they are purchased and used. Consequently when a likely to be considerably .eaten away, and the active life of the cellis, therefore, seriously impaired. f

- In order to overcome the objection to which, I have just referred, I prefer to pro- In the accompanying drawing, the single v ew 1s a diagrammatic vert cal section of vide a paste" Which is initially devoid of. ammonium chlorid. The paste is preferably composed of Wheat flour or some other c-ereal, zinc 'chlorid-solution, and a mercury compound. In makingup a batch of paste mix together, for example, 12.5 kilograms" of wheat flour, 50 litresof zinc chlorid so-.

for the manufacture of a number of cells, I

l'ution 'at 27 Baum and 12.5 grams of mercuric chlorid. The ingredients are mixed together until allof the flour'is dis-1 solved, andthe mass "is stirredI, while being which are in a fine state of subdivision,v are;

cooked, until a stiff paste is ormed. The cooking is effected before the paste s placed in the cell.

The'depolarizin'g body preferably com prises a mixture of manganese dioxid, graphite,- and ammonium chlorid; for example, -in' the proportions of 37 .5 un1t s of manga-- nese hydrate of the kind hereinafter described, 12.5 units of graphite and 10 units of ammonium chlorid. These ingredients,

mixed with water until the mass is plastic and homogeneous, whereupon it is formed into the block or cartridge 3 about the carbon electrode 2 in a mannerwell understood in the art. P

The paste will keep for a long time and does not have to be used at once owing to the. fact that the zinc chlorid is of an antiseptic nature and acts as a. preservatwe .for the'vegetable substance, e. g. wheat flour. The drawbacks incident .to themcorporation in the paste of' ammonium chlorid which-isa bacterial food, are eliminated. v

When the cell 'is first put together, the ammonium chlorid does not immediately commence its attack on the zinc, owing to the fact that it must first traverse the paste.

The ammonium chlorid passesfout only gradually from the cartridge into the paste and to, the'fzinc. Thus the cell'is not at maximum efficiency when first assembled,

as isOrdinarily the case, but reaches maxi mumefliciency after a definite interval has passed, depending upon the distance between the-depolarizing cartridge and the side wall of the zinccuph" For example, with the'sm'aller sizes of cells commonly used for pocket flash lights, the distance" which has to be traversed'by the principal electrolyte salt before itreaches the zinc, is such that maximumefliciency is not obtained for a period'varying from two, weeks to a month. In a larger size, Wherethc ammonium chlorid'has to traverse a greater distance, the conditions usually obtaining in a freshly made cell do not obtain for approximately three months. Therefore there is likelihood that the cell will'not reach its maximum 'efliciency until about the time that it is placed. in use. At any rate-the life of the :cell in the hands of the consumer is 'conslderably increased owing to the fact that the length of time that the ammonium chlorid acts on the zinc previous to the use of the cell, is considerably reduced.

' satisfactory.

In the case under discussion, the am} monium chlorid passes outward through'tlte porous'envelope 5 of the cartridge into the paste and to the zinc, and the zinc chlorid in the paste passes into the cartridge; but it will be apparent that the invention isnot limited to acell wherein the depolarizing cartridge has a porous envelope, Regardless of whether or not an envelope is employed, ,the paste takes "up ammonium chlorid from the cartridge and the cartridgetakes up zinc' chlorid from the 'paste. Furthermore these substances are distribcell.- Heretofore, in manufacturing cells wherein the paste contained both zinc chlorid .and ammonium chlorid, there .was .considerable difiiculty in properly proportioning these two substances. It was necessary .to'weighthe substances andto compare the density of their solutions, etc.,. and even where great care was exercised in compound- I ing the paste, theresults were not always In the present. case, however, the process of manufacture is considerably simplified. because it is not necessary to mix the chlorids and because such great care in attempting to reach a definite proportion of the ingredients is unnecessary. With my improved cell, the ammonium chlorid is fed or supplied to and taken up by the paste in the proper quantity for the best working, and the zinc chlorid is fed to and taken up by tlieeartridge in the proper quantity I forbest working, regardless of the quanti- *uted as needed forpthe best-working of the Y llU which is thrown down as a line precipitate of dark blue color. By analysis a sample of this recovered manganese compound has been found to cont'am the following:

. Per cent Moisture, auimouia'and" other volatiles at 200 C 17.30 Manganese dioxid, -ca-Iculated' from available oxygen 58.74 Manganese dioxid', by anal vsis- 50.97 Water soluble extract, org'anic and inorganic (including carbonates) 8.21 Ammonia vby distillation .00 Carbon. dioxid, from soluble carbonate-" 1,07 Carbon die-xid, from insoluble carbonate 1.93 Insoluble sulphates as S03"--- .34 Sulphur from organic compounds .31

Silica (Si .14 I .13 .045 Iron, sulphides, phosphates, etc... Traces Trace Carbon (tree) as capacity, the remaining one-third will be 'ment, hereinafter desorib l has been proposed heretofore to utilize materialof this-general character as a depolari'zer. in a dry cell, butlsozfar as 'I fan-1 aware,- it has never-been used very successfully for that purpose. After considerable may. be converted into it depolarizer for dry-cell material, is mixed with a-"properj amount of gr'aphiteor like conducting,material..,

, In accordance tomyinvention,Ijpurifythe recovered manganese compound pro-fr erably the manganese recovered in the manufacture of saccharin, by lixiviation:

with a" solution of a neutral, salt, suclrvas ammonium chlorid. The manganese com "pound as received from the sacchannworks is dumped into a suitabletankhaving a perto receive-the solution which is to be poured, In making the particular. cell herein lt-lt tldtt p e 6y ma ena er rea men "ellnnnated. Furthermore, a cell in which forated or sereenlike-bottom. 0n the'bottom Y of theitankli s' placed a suitable piece of filtering material, such as cloth. 'HA'cert'ain amount of space'is left at the top of the tank 1n. described, I employ as a lixiviating or leaching agenta solution of ammonium chlorid of usual electrolyte concentration, say 2 Banme.- A quantity of this solution is poured into the top of the tank, onto the material, and permitted to .percolate through it. If it be assumed that the manganese material takes up two-thirds of the tank filled with the solution, which will pass comsay, twenty-four hours. Anothersimilar quantity of the solution will then be poured into the tank and allowed to-"pass down botto the same is tested in any suitable manner which permits comparison with the solution being poured in at the top, for example, by means of a hydrometer. The increase in density will show strongcontamination of theliquid during the first stages of the process, but gradually the impurities in the solution will thin out and a decrease of approximately 1409 F. During the drying density will be noted until the 'solutioncoming out -.of the tank at the bottom'has the same density as that poured in at the top. No further tests are then needed; The

material is then removed from the tank or vat and dried thoroughly 1n a hot room where itis Subjected to a temperature of such material; v

this i s-notessential in allcaseslf A sampleof therecoveredmanganese com- 7-5 moniuin chlorid solutiomasherein described,

. and "which hadv initially :the constituents 'table' was found to v pecially.those t the miniature type," when the .treated.

of the purified .material, the same takes up a '6 f considerable'amount of oxygen, due to the removal of the impurities, It is preferable a p toexpose the'purified material to the air for some time, beforeit is mixed with :the carresearch and experiment, however,- I 'ha-ve --bonaceous material, so that a ni'ammum found that by "a special preliminary .treatamount of oxygenwillbe taken up before it pound after the treatment' with. theamnoted "in the preceding contain the following J Per cent. Moisture, ammonia and other volatiles at 2009' C. 30.00 Manganese dloxid, calculated from available oxygen Y I 64.89 Manganese dioxid, by analysis.... 65.64 Water soluble extract, organic and inorganic (including carbonates) .41 Ammonia thy distillation-(included 1D first item) 5.07,- Carhondioxid, from soluble carbonate .47 Carbon diox from insoluble carbonat .32 Insoluble sulphates as S0 .10. Sulphur from organic compounds .35 Silica (S10 .14 Lime as-CaO .09 Chlorine as soluble chlorids 0 2 Iron, sul hides,'phospi1ates, etc." Traces Carbon free-)' Trace By comparison of the two tables, a will 'be seen that the available oxygen content has been remarkably increased. A considertion before the material is used in the cell.

By the treatment herein described, the shelf life of the cell. is considerably increased, owing to the fact thatthe impurities likely to set up deleterious local action are used in the depolarizing mix usually has one into the material in the same manner After i or more markedly superior electrical charac'.

teristics as compared to a cell containing the original manganese compound. For example, intests of two No. 5 cells, designated A and B respectively, in which cell B contained the untreated manganese (other factors beshown:

Open Short v Internal Serv ce Class. 25%;; resistance capacity (volts). (amperes). m

'It will be observedthat the increase in service capacity is especially noteworthy, al though the increase in short circuit current the following resnlts' were is likewise important. Of course, the augmented service capacity is explained by. the

. marked'increase in the oxygen content-of the manganese material in the depolarizer. The

improvement'in the other three electrical characteristics-is not to beexplained so readily, but is nevertheless of great practical importance. 1 I

' The particular tests, above mentioned, were madeiiminediately after the assembly of the cells in question, with the ammonium chlorid in the mix only, and the zinc chlorid obtained,

has been assembled, it can be successfully used when freshly'made. If, however, the

cell is allowed to stand for some time before being placed in use, as is usually the case, a discharge Curve, which is extremely good, can be obtained. Under the most. favorable conditions, cells of the kind just mentioned have shown a useful life of 710 minutes (continuous service). The cell also hasvery good powers of recoverywhen used intermittently.

The improved characteristics of the cell containing the artificial manganese dioxid',

preliminarily treated as herein described,

are believed to be due in a large measure to the removal of impurities in the manganese compound which prevent a. free absorption .of oxygen, and-setup local action. The impurities vary somewhat, depending upon the chemicals used for precipitation, but lime and I otashare frequently found. When chemically combined with the manganese, these impurities areinsoluble-in water, and when it is attempted to separate them out by use of acids, for example, as has heretofore been proposed, the result will either be that'the manganese compound is dissolved on the one hand, or on the other hand, that insoluble compounds are created. When my process has been practiced, and the impuri- V ties removed, the manganese compound will absorb a large content of oxygen, which. it

' gives 'up freely when the battery is in use,

so that a very good depolarizing action is obtained. Due to the absence of the impurities, also, the manganese compound quickly reabsorbs a considerable amount of oxygen after the cell has been used. -The precipitate which I prefer to use is, as stated, a

residue from potassium perinanganese thrown down as a fine dark blue precipitate.

This material, more especially the by-prod not of saccharin manufacture, seems to be especially well adapted tothe ammonium 'chlorid treatment. Insoluble compounds are not created as would-be the case if an acid were used for leaching, and yet, as a result of the porosity of the material, or otherwise, the treatment is very efiicacious and beneficial.

I C.) not claim broadly herein a dry cell having an electrolyte which is initially spaced from the zinc cup, but Which grad.- ually works its way to the cup, as claimed in my application Serial No. 346,694; nor

do I claim herein the new depolarizing material oithe method of making the same, as

' claimed in the parent application, Serial No:-

360,553, previously mentioned; nor do I claim broadly herein the. purification of manganese oxid material for various industrial purposes by leaching the same- With a neutral solvent, as claimed in my application, Serial No. 299,522, nor the method of making a primary cell having a depolarizer and an electrolyte. which comprises as a preliminary step the leaching of the depolarizer with a solution containing electrolyte material-prior to the assembly of the cell, as claimed in my application, Serial No. 340,7 52. I

Various .changesiand modifications may be made in the detailed procedure herein described, and in other matters, without departing from the scope of the invention, as defined in the claims.

What I claim is: I '1. In a dry cell, a zinc cup, a carbon electrode, a cartridge surrounding the carbon electrode, containing a dark blue manganese oxid precipitatm the same being a pretreated by-product from the manufacture of saccharin, wholly insoluble in a solution of ammonium chlorid of 2 cell is freshly made, and a paste interposed between the cartridge 'and'the cup.

2. A dry cell of the character set forth,

Baum when. the

having a depolarizing mixture of manganese dioxid and carbon, and a surrounding paste, wherein the activating electrolyte is initially contained in the depolarizing mixture but not in the paste, and wherein the manganese dioxid is pretreated with a solution of v such electrolyte-material.

3. In a'dry cell, a zinc cup, afcarbon electrode therein, a depolarizing body about the carbon electrode composed of a mixture of carbon and an oxy-compound of manganese pretreated with a solution of ammonium chlorid, said depolarizing body also contain-Q ing ammonium chlorid, and means for retarding the action of the ammonium chlorid on the zinc cup, comprising a paste interposed between the depolarizing body and the cup and substantially devoid of ammonium chlorid \vhenthe cell. is freshly made.

4. In a dry cell, and in combination with the negative'carbon electrode thereof, a depolarizing cartridge containing ammoniumchlorid-leached artificial hydrated manganesefdioizidWhentheceII ,islfreshly made .16. In a dry cell, a zinc cup,n carbon 65 5. In a dry cell, and in combination 1 with then'egative carbon electrode thereof, a: depolarizing cartrldge conta n-111g ammonium- 1 5 chlorid-leached dark blue manganese precipitate when the cell is freshly made. '6. In a dry cell,=a zinc cup, a carbon electrode, and'p-retreated. manganese 'oXid precipitate surrounding the carbon-electrode and having a high oxygen content, less than one per cent of carbonates, and practically free'f-rom lime.- v

7.111 a dry-cell, and in combination with the 1 negative carbon electrode thereof, 15, body of artificial hydrated manganese material, preleached with electrolyte material.

38. A dry cell containing'dark-blue arti ficial manganese, depolarizing material containing' less than one'per-cent'of carbonates and practically free from lime'.' 1 I 9.-A dry cell containing dark blue' -recontaining-less than. one per cent offcarbon'ates' and practically free from lime.

. 10. In 'a' dry cell, a'zinc cup, 'a carbon electrode, a. depolarizing cartridgecontammg -an electrolyte-leached vdark blue manganese oxy-compound.precipitate of the saccha'ri'n-a by product type,'-and a paste interposed betweenthe cartridge and the cup. r 1

11. Adry cellhav'ng a depolarizingbody- 7 initially containingk approximately- 37 .5 units of manganese oxid imaterial, 12.5 units a of carbonaccousematerialf 1 Of-.'u1lltS.-IOf

' y llw. I leached manganatefferivative. inlthe' form of ranextremelyfine dark bluepoWder'locatecl electrode," such material '0 being substantiall devoid of potashand at-aflinity. for oxygen. f v a e c -e monium chloridf'ofjvlisualg'electrolyte" cons; centration when. the ';is" flfreshly made.'- ,j

, about 5 the. z'earibcn l e'e f havin'gand wholly'ifinsoluble carbon rod therein, a paste'adapted to carry' an exciting -.agent and a; depolarizing;-

body interposed betweenthe I paste and ;-the

carbon ,rod. and comprising preleached "dark 5o blue'mang-anate derivative; 3

- andf'mixed with, additional ammonium chlorid, and av paste interposed between said dioxid and said cup and substantially devoid of ammonium chlorid when the cell is i facture, and being substantially devoid of freshly made.

15.. In -a dry-cell," alcarbon,

inactive thereon.

covered:- manganese-depolarizing material manganese dioxid surrounding the carbon electrode, and an activating electrolyte solution mixed with such manganese (llOXlCl, but

.17. "In a dry cell, a zinc cup, a carbon electrode, ,anelectrolyte-leached artificial electrode, .anelectrolyte leached artificial manganese 'dioXid surrounding the carbon electrode, and an activating electrolyte soluti'on mixed with such manganese dioxid, but inactive thereon, such-dioxid consisting of dark blue'manganesc 'OXld precipitate.

' 18. In a dry cell, a zinc cup, a carbon electrode, and a depolarizer, surrounding the carbon electrode and containing purified manganate derivative.

19. In a drycell, a zinc cup, a carbon electrode, and a depolarizeiwsurrounding the purified fine precipitate of dark blue color derived; from potassium permanganate.

20. a dry. cell, a zin'ccup, a carbon electrode, and a depolarizing body 'sur rounding the carbon electrode comprising J an electrolyte-leached manganate derivative Wh'en'the cellis'freshlymade;

'21. In a dry cell, afzinc, cup,"a carbon electrode and a depolarizing body surround I ing the carbon electrode comprising an electrolyte-leached potassium permanganate derivative when the cell is'freshly made.

carbon electrode, such depolarizer being: a i

.. 221111 a dry cell, a zinc cup, a carbon" electrode therein, and a body. of depolarizing material-surrounding the carbon electrode, andcomprising a dark blue man .glanese (horrid-precipitate, the same. being a erivative of potassium "permanganate and Wholly insoluble in a solution of ammonium chlorid of usual electrolyte concentration When-the .cell'is freshly made.

23..In .a dry cell, a zinc, cup, a carbon electrode 'therein,.a body of-- depolarizing material surrounding the carbon electrode and containing a' {dark blue precipitate wholly insoluble in an ammonium chlorid solution of usual electrolyte concentration Whenthe cell is assembled, the same being facture. i 2% In a dry cell, a-zinc cup, a carbon electrode therein, a body WhOlly insoluble in .an ammonium chlorid a purified by-produ'ct ofj saccharin manu-' I of depolarizing .material surrounding the carbon electrode "and containing a dark blue precipitate a purified by-product of saccharin manupotash and lime and soluble carbonates.

' 25'. Ina dry cell, a zinc cup, a carbon electrode, and a'body of depolarizing material surrounding the carbon electrode and comprising, when the cell is freshly assembled; anmmmn1nel\l01'i(lleached dark blue tate, the same being a mangannte derivative manganese precipitate of the saceharin byeOntaining less than one ,per cent of carbonprocluct type.

26. In a dry cell, a zinc cup, a carbon similar impurities.

. 5 electrode therein, and a body of depolariz- In Witness whereof, I have hereunto set ingmaterial surrounding the carbon elecmy hand on the 30th day of April, 1920'.- trode, and comprising a dark blue precipi- HAROLD DE OLANETA.

ates and substantially devoid of lime and 10

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