-@2 1,854,17(3 trol te containiiig ivhat, 1-nal, be calle,-l "ai oxid,,ttion transfer @tgent". 'Suitabl-e ageiits for this purpose ire the salts of iaaetals s,,lch as t-itaiiium, vanadium and ceri.um ivliieh ,trecharacterized by the ease i,7itli which their s,Llts of bi(yhe@,, valence are recILiced by hydrogen tLd the ividity )ii'th ivhich the salts of lower valet-ice react mith oxygen, or other oxiclizing ,i-ei-its to prodtice tlie si.Its of z@ 10 Iii(yher valence. n For example I m-,iy prep,-Lre ,iia electi,o,lyte cont,iip-lng amiiioni-,oii-i chlo3-icl,- aiicl, frorfi 5-50@'o of 'u'lt,@initim tetrachloride. Zinc r,liloride ,iiid other salts may also be present IC, if desired. I iuay -Lise said electrolyte in a Le Clanclie cell of either the -wet or so-called :drv t-y@l-,.e. Vioiys ip- stiel, a cell th@ fir'st e@ffect of the geiier,,ttic@n cf hydro(,en i-sw to reduce ',he, tetrivalent titanium to iri'20 i,aleiit titaiiiiiin. @ln, this respect ti-ie@ tqtrava,len'L, tit,,tni-LIm acts momentarily, as @t @depolarizer. Ho-wever the trivalent titaniuin is itself @an excelleiit ,ictive reclucing,agent and it retets with the depolarizer to recltice the saiue, beiiig i-eoxidizecl to tetravalent titani,-Liiii in the process. Depolarization is thus improved. o-n account of tl-ie active red-LLein- agent presciit iii soltition. The dep36 ,-3 5 osi 'tion, of gaseo Lis hydrogeii in the depolarizer p@irticles is aaoided. The -effect of iiiy,invention is 'Lo greatly iinpr,ove the clepol,,irizing action,of manganese@dio.Nide in an,ordiTl,,try.Le Clanche cell,but the adv@qntage is even more@striking in @ tlie case of t. cell in -,which, a solid oxide of carboii is -used as the clepolarizer. ,In,this lattei, type of cell, depoltrization is probab'l.Y purely physic,,tl.and may take place, in the greatest deo-ree,@ only,between gaseotis @l@),Iiydro(yena.ndthesolicl-carbonoxide. When tetravalent -titanium is present in the electrolyt.e it is redLiced---@-in sollition@by tlie .igener@-@tioii,-of,h3,drogen,ions during cell disch,,Lrge. The res-Liltant trivalent,tit,,inium is ileoxidized by,the solid c,,irbon oxicle as@ rapid ly.,as it is,foriiied. In @tny.event,tlie effect oi,tl-ie preseiie-e o -tlie7 'titaniuin,s,,tlt toele-v.ate.tlie,clisch,irge rite iii closed eircuit@and to,gre.itly iiiipro-ve the,.cell. -1)( While -I have described the i-ise of chloride tDf tit,,tniunl,in.iny iiiipronecl cell,.l m,,t3r-al-.t,eriiativel3T eii-iploy the chloricles of.ceritim, N@,ctnadiuin, or other simil,,tr @ metals. ,-"Thile I baie described ii -iy invention in conneetioi -i ivith the Le Cl,,tnclie.typ,e of cell it.n-io,y obviously be tised in other,cells. For 7Bxa.mple I,niay 1)repare,a cell htving electrodes of carbon ,ti-id iron and I may.emplqy .titanic sul@-ate or eerie s Lilftte as an ingredieiit of the eleetrolyte. Now having described my in%,ention, I .claim,the following.as new@pnd novel:- 1. Inaprimai-,yeellconta-ining,@idep-olarizer .a.nd,a, carbon,electrode, an electrolyte con5@7) taihing, a salt of @tit,,iniLLm. 2. In a primary cell containing a depolarizer and ,t carbon electrode, an electrolyte containing a chloride cf titanium. 3. In a primai-y cell, the coi-abination of a iiietal electi-ode, a carbon electrode surround- 70 ed by a solid depolarizer, tnd an eleetrolyte coitai..Diiig a salt of titanium.. .4. In a-'Le Clanche type priiiiary cell, an electrol3Tte containilig a chloi-ide of titaiiium. 5. In a Le Clanche type priinary cell, the 75 coiiibiiiation of @-a ziiie electrode, a carbon electrode stirrounded by a, solid depolarizer, an@t -a-n electrolyte containing a chloride of titailitim. 6. In a Le Clanche type primai-y cell, the 80 combiiiation of a,zine @el-ectrode, :a carbon electrode -stirrouncled @y @a solid, depolarizer containino@ a carbon oxide,,aiid, an electrol te tn I y containin-- a chloride -of -titanium. t, l@n testin-iony wliereof,,l have.si,-ned my 87) iiaiiie to this specificitioii this-2ii.cl (I.,ty of ftilv, 1928. -BR-UCE K. -BROWN. !)5 1. 120 125 130

Patented Apr. 19, 1932 19854@176 UNITED STATES PATENT OFFICE BRUCE K. BROWN, OF PELHAM, NEW YORK PRIMARY CELL No Drawing. Application filed Tuly 16, 1928. Serial No. 293,305. ,iqy inventi6n relates to tn improved primary cell a-nd portaiiis;more particularly to use of a SOILT the ble titanium compound in the electrolyte of such. a cell. @ While generally 0 applicable to primary cells, my invention is particularly usef til inconnection with the Le Clanche type of cell. The Le Clanche cell coiisists of a zinc electrode and a carboii electrodelimmersed in an 10 electrolyte containing ammonium chloride and zinc chloricle. When the electrodes of stich ,L cell are connected, a current flows. Zinc chloride is forined at the zinc -electrode and hydrogen and ammonia, are generated at th carbon. Siich ,i, cell would polarize very quickly, were it not for the presence of a soII4 clepolarizer which is place4 around the elec-, trode. This consists, usually, of manganese dioxide rendered conductive by admixture Nvith carbon or graphite. The hydrogen reacts with the ii'langanese dioxide, producino, water, and polarization is thus prevente(f Such ,t cell produces an E. M. F. of ,)boiit 1.5 Volts when first pi.,t in use, blit the internal resistance of the cell inere,,tses with use and there is a gradual poltrization accompanied by a loss in voltage ancl aiiaperage. The -Lise of the Le Clanche cell is wide sl)read, particularly in the dry cell form. Reference is iiiade to "Primary Batteries" by W.,R. Cooper, 1920 edition published b3r Benn Brothers an6 to Ci-rcular No. 79 of the TT. S. Bureau of Standards, published by the Government PrintiDg Office in 1923, ivhere the art is -well summarized. In the dry cell form of the Le Clanche cell, the manganese dioxide depolarizer is forined as nioist core around the carbon electrode. This core is us-Lially wrtpped in some bibulous material and placed in a zinc can electrode which contains an qiumonium chloride-zinc chloride electrolyte m,,),de pasty by the presence of sarch or soine other cereal (c. f. Schulte, U. S. Patent 1 370.056). G a hitic I r p 45 oxide or solid oxide of carbon may be Lised as the depolarizer in place of manganese dioxide. This material may be manufactured in accordance witli tl-ie method disclosed in illy prior Patent No. 1,639,980. Its use in ,i 5@j dry cell is described in my prior Patent 1,639,983. Solid oxide of carbon iuay be Lised in admixture -with manoanese dioxide as disclosed in my prior Patents 1,639,984@5. I have now discovered a method of improving the depolarizing action in the Lle Clancl-ie 5 type of cell and by nieans of my I invention I prod uce a cell which does not deteriorate so rapi dly on closed circuit and which produces a higher voltage during continuous dischar ge. 60 It @is -a f act well known to those skilled in the ,trt that the depolarizing actio--q of the Le Clan che type of cell is ineffiecient. When inan-anese dioxide is lised as the depolarizer the cell "r-Li-ns down'7--i. e. din-iinishes iri 65 volta ge -,tnd tmperage @ and increases in intern all resis'udnce-long before all of the maiigane se dioxide present is reduced to the mangino us form. This may be due to the local iiatiir e of the depolarizing action ivhich TO see ms to take place onl)r in the vicinit of the dep olarizer itself. It may also be @artly dtie to the adsorption of ammonia. In the case of a Le Clanche type of cell empl oying a, depolarizer of oxidized carbon, 7,5 this eite6i is even more noticeable. The effecti ve voltage on closed circuit is even lower than in the case of cells depolarized with man ganese dioxide. This may be due to the fact that the potential difference in the cell 80 may be that between oxygen and carbon or betw een carbon oxide and zinc blit I tl-iink it is more probably diie to the plirely physical character of the depolarization. In other wor ds a part of the depolarizing action of 85 Mn Oi! may be due to the formation of (tuadra@ alent manganese icins, whereas no stich possi bility exists in the case of oxidi7,ed ca'rbon. In this latter case the oxy-en content of the solid oxide is quite possibry adsorbed 90 by the carbon, which is geiierally supposed to be a colloidal oxid(,@. In any'event it @is 6bvi ous that depolarization i-n-List occur only as the' res-Lilt of contact of the hydroo-en ions and possibly gaseous hydrogeia, witl-i the depola rizer. . I have.now discovered that the depolarizing action of the Le Clanche type of cell may be improved, and the voltage during dischar ge thus sustaine.d, by the Lise of an elee-