Feb. 16, 1954 W. W. GARY, JR 2,669,595 ALKALINE BATTERY Filed Dec. 18, 1950

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ALKALINE BATTERY Wrightw. Gary, Jr., Pasaaenacaliß. Application December 18, 19510,’1Serial‘ No. 2011,451': 11 Glaims. (c1. 13s-_suil l This invention relates to an alkaline‘ty-pe of -2 storage battery, and particularly to a‘battery a novelvî cell' constructionand, incases Where having. the coupleur silver'and zinc inanalkalìne quick' charge? characteristics1I are desired, ay small electrolytes. percent. of: an ‘alkalishalogen >catalyst mayV be The couple of silver and; zinc has- been long addedf' to thefele'ctrolyte; Due to» this improved known: for ' its dependability; and eñîciency in the construction, Ag()A or'AgzO'zv` is formed onf charge primary “chloride cffsilver.” cell. However, this instead of AgzO, as experienced inaprior'attempts cell is» not feasible for­ manyindustrial applica te devisek a storage. battery of this type. This tionsV because it cannot be 'recharged and used permits'fle‘ss chemical to `bef-used for the same aga-in,­ andhas> comparatively» lowI voltage: char' ampereA hour' eiiiciency. _ acteristicsrequiring‘a large number of cells -per The present invention-ï en`ectively uses metallic installation, thus makin-g installation and main silver, silver oxide, or’silverihydrateas the active tenance costly. anode coupled with any­> suitable Vcathode in.- an Alkaline storage. batteriesy making use oi'silver alkaline electrolyte. Bya». new'construction, the silver is` confined and> passivity ‘and’ internal have been unsuccessful due to the difûculty of 15 keeping the silver confined to the anode during resistanceware reduced to a minimum in an economical manner. Size and weight, with re charge and discharge. Colloidally ñne -silver spect to capacity, aref-also> reduced; , oxide. passes throughv periorate pockets, tubes, or The principalobject of the invention, therefore, gauze, and gradually poisons theI cathode, is to `provide "an improved silver-zinc storage shortening the life of the cell; The ygiresentA in- ` battery. vention employs a dialyzing membrane ‘which eiîectively prevents the colloidal silver fromI being Another objectof theY invention is. to provide displaced. The “chloride of silver” cell, the pri' an improved` construction. to retainY colloidal mary cell using silver and zinc inra sal ammoniac silverïwithin the: electrode of an~ alkaline battery. electrolyte, 4has an E'. M. F. oi 1.02 volts. The A; Íurther‘ object of the invention is to provide an. alkaline battery- constructionV which reduces well-known nickel-iron and'nickel-cadmiumcells passivity-“andi internal‘resistance to a minimum. have an E. M. lF'. of 1.1 to 1.2 volts. Thus,­ 98 A still’f'further object of the invention is to and 83 cells respectively,` would be required for providefa silver-zinc battery'having high ampere ar one hundred volt circuit. The E. M. F. of the hour 4‘output per 4unit weight. present invention is 1.5‘to 1-.6 volts. The. require- c lAlthough` the-novel features which are believed ments would> thus be reduced to‘63 cells. per -one to lbe­ characteristic of >this invention willA be hundred volt circuit, a decided advantage-where high voltages are desired. pointed out with particularity in the appended ciaims, >themanner of its organization and the Internal resistance of the “chloride of silver” mode’ of. its' operation will be better understood cell is in the order of magnitude of four ohms I" by referring tath'effollowing description, read in per cell andrnickebiron and nickel-cadmium ‘cat/ conjunction: withA >the accompanying drawings, teries are also high in internal resistance.` This ­forming a. part hereof, -in-v which: resistance can only loel reduced. by costlyy con Fig. 1. isz-a perspective View' of a battery em struction. The internal resistance of­ the pres bodying; thel invention, and entl invention is lessI than 0;016 ohmper celly and 40 Figa is a, cross-sectional view of the battery constructionk is simple and inexpensive. taken along; thev line •2••’••2• of Fig. l. Another disadvantage in the use: of. silver is lReferring;novv to: the drawings,` in which like itssusceptibility to passivity; that,is„ a theoretical numerals'identify >the'same‘ elements, an external monomolecular oxide nlm forming on. the sur' case" l2.l of cylindrical shape may be> of suitable face of the silver­ during rapid' chargc,.`thus'pre.­ steel >or vplastic with a. lining A25J oi _nickel Vvfoil venting further oxidation' or activity. Silver, if can-nickels pla-te;> When thev case. is.r nickel plated, charged at a low rate, is easily oxidized> in an the >first nickel deposit isv annealedi and then alkaline electrolyte and. passivìty is introduced plated again.. The lining 2-0 forms the conductor as thecurrent density isiincreased.v An example take-off from; the negative electrode and may of this> is, if a silver anode" is charged at50 ma'. 50 havea. terminal extension Hiv therefrom which per square cm., thev anode becomes passive; >if is rivetedftoithe‘lining, 2li-fat- lI'S and‘ embedded in charged at 201- ma. per squarev cm., the anode the:coverwlfl.4 @ther forms of- attachmentof slowly regains activity.; if' charged at lLorna. .per the terminal> 1,6, may betmade; ` square cm'., .periodic .passivity -isrobserved'.. -ïnthe positive 'electrode'. is shown. asÍ a. nickel present invention, thisI condition: is: improvedè by 55 It..‘b11’lî«‘1t|1ayA also 'be inthe: forml of. a spiral 2,669,595 3 not enter into any permanent chemical reaction nickel wire or a nickel foil. The end I0 of the with the active chemicals. rod I4 extends through the cover II to form The cell just described does not exhibit a rapid the positive terminal. Surrounding the rod I4 temperature rise at high charge rates, which is and spaced therefrom, is a thimble I3, which is so common in alkaline batteries, and has been a dialyzing membrane of paper, suitable ceramic, successfully operated at approximately 123 de or plastic, of such porosity that it will allow the grees F. without detrimental effects. free flow of electrolyte and yet prevent the es Although this is the preferred embodiment of cape of the colloidal silver. The open end of the invention when silver is coupled with zinc, the thimble is attached to the cover II. 10 an equally appli-cable structural design will be The proper porosity of this thimble membrane found in my co-pending application, Ser. No. I3 is critical. If porosity is too large, the silver 192,873, filed October 30, 1950, where the silver will escape its confines, and, if too small, the may be mixed with the nickel salt before hydro internal resistance of the cell is obviously in gel precipitation, or the silver may be used alone creased. One mode of achieving proper porosity as set forth in this co-pending application. This is by impregnating a heavy weight filter paper alternative design is especially desirable when with a saturated solution of magnesium sulfate, the silver is coupled with iron or cadmium and allowing the impregnated paper to dry, and then where pressure is required for their increased dipping the paper in an aqueous solution of sodi emciency. However, independent anode and um hydroxide. The membrane is then washed cathode venting is necessary as well as the dia free of soluble salts. The resulting precipitate, lyzing membrane, as described above. magnesium hydroxide, residual in the matt of I claim: the membrane, sufficiently »prevents silver dis 1. A silver-zinc storage battery comprising a placement and allows free electrolyte flow. Cer positive electrode having a nickel element, a neg tain thixotropic clays, natural or artificial, may ative electrode having a nickel element, a dia be used to form said membrane in any well lyzing membrane between said nickel elements, known manner. a silver oxide between said ñrst nickel element Within the thimble i3, is finely granulated or and said membrane, zinc between said membrane pelleted silver oxide I5, which is metallic silver when the battery in in discharged condition. and said second nickel element, and an electro 30 lyte in which all of said elements are immersed, Where high discharge rates are desired, nickel said electrolyte being potassium hydroxide, to powder or flake may be added to the silver. The which has been added an alkali-halogen com anode, thus described, is supplied with a check pound. vent I8, over an opening 9, through cover II, 2. A silver-zinc storage battery comprising a which will allow ready escape of liberated gases, yet prevent ingress of carbon dioxide-bearing 35 positive electrode having a nickel element, a neg ative electrode having a nickel element, a dia atmosphere. Between the thimble I3 and the negative take lyzing membrane between said nickel elements, off conductor 2G, is metallic zinc dust 2I, which silver oxide between said first nickel element and forms the negative electrode. Although zinc is said membrane, Zinc between said membrane and 40 said second nickel element, and an electrolyte preferred, any suitable cathode material may be in which all of said elements are immersed, said used. This zinc dust, during the first few cycles electrolyte being potassium hydroxide, to which of charge and discharge, forms a porous rigid has been added potassium bromide. mass to which may be added, by mechanical mix 3. A silver-zinc storage battery comprising a ing, mercury or mercury oxide for additional con ductivity. If rigidity is neither necessary nor positive electrode having a nickel element, a neg ative electrode having a nickel element, a dia desired and semi-immobilization of the electro lyte is required, magnesium oxide or zinc oxide lyzing membrane between said nickel elements, may be added to the zinc dust. Mercury may silver oxide between said iirst nickel element again be added to increase the conductivity. and said membrane, Zinc between said mem Whichever form of negative electrode is used de brane and said second nickel element, and an pends upon the use to which the battery will electrolyte in which all of said elements are im mersed, said membrane being a heavy weight fil be put. The cell is then filled with potassium hydrox ter paper which has been impregnated with a ide electrolyte 1.22 to 1.25 sp. gr. at 18 degrees C., solution of a magnesium salt internally precip itated and having a porosity such as to permit to which may be added a small percentage of an alkali-halogen compound, such as potassium bro the free flow of said electrolyte and not the flow of colloidal silver. mide, for the reason mentioned above. rI'he 4. A silver-zinc storage battery comprising a cathode, thus described, is supplied with a check casing, a nickel lining for said casing, a nickel vent I'I over opening 8 in cover II, which will element surrounded by said casing, a porous dia allow ready escape of liberated gases, yet pre 60 lyzing membrane surrounding said nickel ele vent ingress of carbon dioxide-bearing atmos ment and spaced therefrom and from said lin phere. However, there is little gasing on charge ing, pelleted silver oxide between and in contact and the cell is virtually free from gasing on dis with said membrane and said nickel element, charge. Although the battery has been shown 65 metallic zinc between and in contact with said in cylindrical shape, it is tobe understood that membrane and said lining, an electrolyte in which it may be constructed in any desired shape and all of said elements are immersed, said zinc being with any number of dialyzing plates or thimbles. in dust form, the liberated gases therefrom being The addition of small percentages of an alkali separated from the liberated gases from said sil halogen compound, such as potassium bromide, 70 ver oxide within said casing, a cover having a to the electrolyte permits a more intensified cur one-way gas outlet opening above said silver rent density than that obtainable in conventional oxide, and a separate one-way gas outlet open cells using potassium hydroxide, sodium hydrox ing above said zinc is provided for said casing. ide, lithium hydroxide, or-combinations thereof. 5. A silver-zinc storage battery comprising a This alkali-halogen functions as a'catalyst to casing,y a nickel lining for said casing, a nickel reduce passivity at high rates of charge, and does 75 2,669,595 5 , 6 element surrounded by said casing, a porous dia comprising a heavy Weight filter paper which lyzing membrane surrounding said nickel ele has been impregnated with a solution of a mag ment and spaced therefrom and from said lining, nesium salt internally precipitated. pelleted silver oxide between and in contact with 10. The method of forming a membrane for said membrane and said nickel element, metallic filtering colloidal suspensions from liquids con zinc between and in contact with said membrane taining said suspensions, comprising impregnat and said lining, and an electrolyte in which all ing a heavy Weight ñlter paper with a solution of said elements are immersed, said zinc being of a magnesium salt and internally precipitat in dust form to which magnesium oxide has been ing said salt. mixed, and said electrolyte being potassium hy 10 11. A silver-zinc storage battery, comprising droxide to which has been added a small per centage of an alkali-halogen compound. a membrane, silver oxide on one side and in con tact with said membrane, and metallic zinc on 6. A silver-zinc storage battery comprising a the other side and in contact with said mem membrane, granulated silver oxide on one side brane, said membrane being of heavy filter paper and in contact With said membrane, and metallic 15 having a magnesium precipitate in the matt of zinc dust on the other side and in contact With said paper. said membrane, said membrane being of heavy weight filter paper which has been impregnated WRIGHT W. GARY, JR. with a saturated solution of magnesium sulfate, References Cited in the ñle of this patent allowed to dry, dipped in an aqueous solution 20 of sodium hydroxide, and Washed. UNITED STATES PATENTS 7. A membrane for preventing passage of co1 Number Name Date loidal silver and permitting- the flow of potas 457,116 Hard ______Aug. 4, 1891 sium hydroxide comprising a heavy filter paper 942,279 Perry ______Dec. 7, 1909 having a magnesium hydroxide precipitate in 25 1,004,530 Creighton ______Sept. 26, 1911 the matt of said paper. 1,451,003 Wood ______Apr. 10, 1923 8. The method of forming a dialyzing mem 2,317,711 Andre ______Apr. 27, 1943 brane which permits the flow of a battery elec 2,451,805 Callinan ______Oct. 19, 1948 trolyte and prevents the flow of colloidal silver 2,542,710 Ruben ______Feb. 20, 1951 comprising im-pregnating a heavy Weight filter 30 2,601,133 Yardeny ______June 17, 1952 l paper with a saturated solution of magnesium FOREIGN PATENTS sulfate, drying said impregnated paper, dipping said impregnated paper in an aqueous solution Number Country Date of sodium hydroxide, and Washing said dipped 324,918 Great Britain ______Feb. 5, 1930 paper free of soluble salts. 35 OTHER REFERENCES 9. A membrane for filtering colloidal suspen Denison, Transactions of the Electro-chemi sions from liquids containing said suspensions, cal Society, vol. 90, 1946, pgs. 387-401.