CA1088152A - Non-aqueous lead dioxide cell having a unipotential discharge voltage - Google Patents
Non-aqueous lead dioxide cell having a unipotential discharge voltageInfo
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- CA1088152A CA1088152A CA293,225A CA293225A CA1088152A CA 1088152 A CA1088152 A CA 1088152A CA 293225 A CA293225 A CA 293225A CA 1088152 A CA1088152 A CA 1088152A
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- lead
- cell
- oxide cell
- lead oxide
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/14—Cells with non-aqueous electrolyte
- H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/06—Electrodes for primary cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/14—Cells with non-aqueous electrolyte
- H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte
- H01M6/162—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte
- H01M6/164—Cells with non-aqueous electrolyte with organic electrolyte characterised by the electrolyte by the solvent
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
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- Primary Cells (AREA)
- Secondary Cells (AREA)
Abstract
NON-AQUEOUS LEAD DIOXIDE CELL HAVING A
UNIPOTENTIAL DISCHARGE VOLTAGE
ABSTRACT OF THE DISCLOSURE
A non-aqueous lead oxide cell having a negative electrode, such as lithium, a non-aqueous electrolyte, a positive electrode comprising lead dioxide housed in a positive terminal conductive container, and wherein a layer of lead and/or lead monoxide is interposed substantially between the positive lead dioxide electrode and the inner surface of the positive terminal conductive container so as to achieve a substantially unipotential discharge for the cell over its useful life.
1.
UNIPOTENTIAL DISCHARGE VOLTAGE
ABSTRACT OF THE DISCLOSURE
A non-aqueous lead oxide cell having a negative electrode, such as lithium, a non-aqueous electrolyte, a positive electrode comprising lead dioxide housed in a positive terminal conductive container, and wherein a layer of lead and/or lead monoxide is interposed substantially between the positive lead dioxide electrode and the inner surface of the positive terminal conductive container so as to achieve a substantially unipotential discharge for the cell over its useful life.
1.
Description
Field of the Invention . _ _ The invention relates to non-aqueous lead oxide cells, and specifically to such cells wherein the positive electrode comprises lead dioxide housed in a conductive container and wherein a layer of lead and/or lead monoxide is interposed substantially between the lead dioxide electrode and the inner sur~ace of the con-ductive container.
Back~round of the Invention 10- The development of high energy cell systems requires the compatibility of an electrolyte possessing desirable electrochemical properties with highly active anode ma~erials, such as lithium, calcium, sodium and the like~ and the efficient use of high energy density : ~ .:
~ cathode materials,~such as FeS2, Co304, PbO2 and the ~ -. .
~ ~ lik~. The use of aqueous electrolytes is precluded in -.
these systems since the anode materials are sufficiently active to react wîth water chemically. Therefore, in ; order to reslize the high energy density obtainable through ~ use of these highly reactive anodes and high energy density cathodes, it is necessary to use a non-aqueous ~: .
; ele trolyte system.
..
~ One of the major disadvantages of employing lead .
~ dioxide (PbO2) as ehe active cathode material in a non-.
aqueous electrolyte system i9 that it will discharge at two different potentials. The first ~tep in the discharge ~: : :: : : curve is attributed to the reduction of the lead dioxide .
.. . .
~ 2-.
~0~ lSZ
to lead monoxide, while the second step is attributed to the reduction of the reaction product, lead monoxideO
Contrary to lead dioxide, lead monoxide will discharge in a non-aqueous cell system at a unipotential level.
One advantage in employing lead dioxide as the cathode material over lead monoxide is that it has almost double the capacity o~ lead monoxide. Thus in a non-aqueous electrolyte systemj lead monoxide will have the ad~antage of discharging at a unipotential plateau with the disadvantage of having a relatively low capacity while ~-lead dio~ide will ha~e the advantage of having a relatively high capacity with the disadvantage of dis-charging at two distinct voltage plateaus.
Many cell or battery applications, particularly in transistorized devices such as hearing aids, watches ~
and the like, require a substantial unipotential dis- -charge source for proper operation and, therefore, cannot use the dual voltage level discharge which is character-:: :
istic of non-aqueous lead dioxide cells. This dual ; 20 voltage level discharge characteristic is similar to the ~:: :: : , dual ~oltage discharge characteristic of aqueous alkaline divalent s~ilver oxide celle,~ Although many approaches have~been proposed for obtaining a unipotentia} discharge fr~m an aqueous alkaline divalent silver oxide cell, the approaches are not needed when iead dioxide is employed in an aqueous electrolyte cell system. Specifically~ in 3.
~:, ~Lo~
an aqueous electrolyte cell system, lead dioxide will dis-charge almos~ entirely at i~s higher voltage level so that, in effect, the cell will produce a substantially uni-potentlal discharge over the useful life of ~he cell.
Contrary to this, when lead dioxide is used as the cathode material in a non-aqueous eleotrolyte system, the cell will discharge at a first potential for a significant timeperiod and then decrease to a distinct lower potential for the remaincter of the discharge. A problem usually encountered in various cell systems Is that although an electrode-couple can function in an aqueous electrolyte, it is prac~ically impossible to predict in advance how well, if at all, it will function in a non-aqueous electrolyte.
Thus a cell must be considered as a unit having three parts - a cathode, an anode and an electrolyte - and it is to be understood that the parts of one cell may not be predictab b interchangeable with parts of another cell ~ -to produce an efficient and workable cell.
French Patent 2,288,401, published on June 18, 1976 (counterpart to German application 2,545,498 published on April 27, 1976), discloses a non-aqueous cell which employs a negative electrode, such as lithium7 a non-aqueous-sol~ent electrolyte and a positive active electrode consisting of a positive active m~terial of the oxides and oxidizing salts, the discharged reduction of which leads .
~. .
to metals of ~he group including lead, tin, gold, bismuth, zinc~ cadmium and their alloys and an electronic conductor consis~ing at least on the surface o~ a material selected from the group including lead, tin, gold, bismuth, zinc, cadmium and their alloysO Several examples are disclosed in this reference in which lead monoxide is employed as the positive acti~e material and lead9 tin or graphite is employed as ~he electronic conductor. Although this reference teaches one means for ob~aining a unipotential discharge for certain non-aqueous cell systems, as, for example, a cell employing lead monoxide as the positive ac~ive material~ the subject invention is directed to the use of lead dioxide as a positive electrode in a non-aqueous system and wherein a layer of lead and/or lead mon-oxide is interposed between the positive lead dioxide electrode and the inner surface of a conductive container housing said electrode.
: U. S. Patents 3,615,858 and 3,655,450 disclose batteries composed of a principal active ma~erial and a secondary active material and constructed such that the dis-charge of the principal active material is through the secondary active material so as to achieve the discharge potential characteristics of the secondary active material.
: Although the electrolyte for use in the disclosed cells in these reference~ is not specifically recited, the examples in the references all employ an aqueous elec-trolyte system. In U. S. Patent 3,6159858, it states 5.
- . . - .
. ~ . . .
112~0 tha~ divalent silver oxide can be discharged at the potential of lead dioxide. Contrary to this, the subject invention is directed to a cell which employs a lead dioxide positive electrode in a non~aqueous cell system and wherein a layer of lead and/or lead monoxide is interposed be~ween the positive lead dioxide electrode and the inner surface of a conductive container housing said electrode so that ~he cell can be effectively dis-charged at a su~stantially unipotential level over the useful life of the cell.
Accordingly, it is the primary object of this invention to provide a non-aqueous lead oxide cell which employs a lead dioxide positive electrode which is separated or isolated from the inner surface of a con-ductive container housing said elec~rode by a layer of lead and/or lead monoxide and which has a substantially unipoten~ial discharge voltage.
Another object of this invention is to provide a non-aqueous lead oxide cell which employs a lithium Z0 anode and a lead dioxide positive electrode, said positive electrode being separated from the inner surface of a conductive ontainer housing said electrode by a layer of lead and/or lead ~onoxide, and which cell has a substan-tially unipotential discharge.
~D~U~ ' ' The invention relates to a non-aqueous lead dioxide cell having a negative electrode, a positive &.
11~80 electrode comprising lead dioxide and an electrolyte housed within a conductive container; a layer of lead monoxide and/or lead interposed between~ and electrically and physically in con~ac~ with, said posl~ive electrode and the inner surface of the conduc~ive container; and said cell having a substantially unipotential discharge voltage.
A unipotential discharge voltage shall mean a relatively constant voltage level extending over at least 85 per cent of a cell's discharge capacity when discharged across a fixed load~ and wherein the voltage varies no more than + 10 per cent of the average voltage of said voltage levelO For example, a unipotential dischargP level can be represented by a voltage-time curve substan~ially free fr~m voltage excursions or steps during at leas~ 85 per cent of the time of di~charge across a con~tant load, such steps or exeursions being deined a~ vol~age reading~ outside of ~ 10 per cent o~
the average vol~age over the said 85 per cent portion of the time of discharge. Accordingly, it is the objec~ of this invention to effectively eliminate or effectively suppress the portion o the curve to the left o~ point A to yield a unipotential discharge level ~ -as generally shown by the curve between points A and B.
It is also within the ~cope of this invention to add a binder, an electronically conductive material, an eleo~rolyte-absorben~ ma~erial or mixtures thereof to .. . . .
the posi~ive electrode of this invention.
The lead monoxide layer and/or lead layer for use in this inventlon be~ween the lead dioxide electrode and ~he inner surface of the conductive container housing the electrode should be sufficient to substantially isolate or separate the positive electrode from the inner surface of the container such that the lead and/or - -lead monoxide layer will bP the main electronic path through which the lead dioxide discharges.
Preferably, the lead and/or lead monoxide layer should be the sole electronic path through which discharge of the lead dioxide electrode occursO The lead monoxide layer and/or lead layer should be sufficient in thickness to substantially eliminate the two voltage plateau discharge characteristic of lead dioxide in a non-aqueous electrolyte cell systemO A lead monoxide layer is preferable to a lead layer because lead monoxide ~ will contribute to the discharge capacity of t~e cell.
; Useful highly active negative metal anode --materials are generally consumable metals and include aluminum, the alkali metals, alkaline earth metals and alloys of alkali metals or alkaline earth metals with each other and other metals. The term "alloy" as used herein and in the appended claims is intended to include mi~tures 3 solid solutions, such as lithium-magnesium, and intermetallic compounds, such at lithium monoaluminide.
~' 8.
.. . .
The preferred anode materials are lithium, sodium, potassium, calcium and alloys th~reof.
Useful organic solvents employed alone or mixed with one or more other solvents for use in this invention include the ollowing classes of compounds:
Alkylenenitriles: e.g., crotonitrile (liquid range -51.1C. to 120C.) Trialkyl bora~es: eOg~9 trimethyl borate, (CH30)3B.
~ uid range -2903 to 67C~) ~etraa~kyl ~llica~es: e.g~ tetramethyl silicate, (CH3~)4Si (boiling point 127C~) .~ , Nitroalkanes: e ~ g ., nltrome~hane, CH3~02 ~liqllid range 17 to 100.8CO) A~lcylnitrlles: e,g., acetonitrile5 CH3CN
(~quid ~angc ~45 to 81.6C.) : Dialkylamides: e.g" dime~hylformamide, HCON(CE~3)2 (l~quid range -60.48 to 149C.) Lactam~: eOg~ ~ N-methylpyrro:Lidone, CH2~:H2~CH2~::0-N-GH3 (liquid range 76 to 202C~) 20 Tetraa~Xylureas: eO go 7 tetramethylurea, (CH3~2N~O-N~SH3) 2 (li~uld range -1~ 2 to 166C
Monocarboxylic acld esters: e.gO ~ ethyl acetate ~liquid range 83.6 to 77.06C.~ ~
:, ' .
- . ~ .
112~0 Orthoester~: e,g., trimethylorthoformate, HC (OCH3)3 - (boiling po~nt 103C.) r - , Lactones: e.g., ~f~amma)butyrolactone, CH2dCH2-CH2-0-CO
: (liquld range -42 to 206Co) D~alkyl carbonates: e.g" dimethyl carbonate, OC(OCH3)2 (liquid range 2 to 90C.) Al~ylene carbonates: e~g., propylene carbonate, CH(CH3)CH2~0-C0-0 (liquid range -48 to 242C.) M~noether~: e.g., die~hyl ether (llquid range -116 ~o 3405C.) Polyethers: e.g.g 1,1- and 19 2-dimethoxyethane ..
~liquid ranges -113~2 to 64,~C9 and -58 to 83C~, respectively) Cyclic ethers: e.g., t~trahydrofuran (liquid range -65 to 67~C.); 1~3-dioxolane (liquid range ~ _95 tO 78Co~
Nitroaromatic~: e.g" nitrobenæene (liquid range 5,7 to 2~008C.) Aromatic carboxylic acid halides: e,g. 9 benzoyl :; 20 chloride (liquid range 0 to 197C.); benzoyl : . bromide tllquid range _7& to 218Co~
Aroma~ic sulfonic acid halides: e.g., benzene sulfonyl : chloride (~iquid range 14.5 to 251C~) Aroma~ic pho~phonic acid dih~lides: e~g.g benzene . phosphonyl dichloride (boiling polnt 258C.) .
10.
5~
Aromatic thiophosphonic acid dihalides: e~gO ~
benzene thiopho~phonyl dichloride (boiling point 124C. at 5 mm~ ) ' Cyclic sulfones: e.gO 3 ~ulfolane, H2 H2-CH2-CH2-S02 (m~lting point 22C.);
3-methylsulfolane (melting point -1C.) A~kyl sulfonic acid halides: e.g., methanesulfonyl chloride (boi7ing point 161C.) Alkyl carboxylic acid halides: e.g.9 acetyl chloride - 10 (liquid range -~12 to 50~9Co); acetyl br ide uid range -96 to 76.C.~ propionyl chloride (liquid range ~94 to 80~..) Saturated heterocyelics: eOg~, tetrahydrothiophene (llquid rang~ -96 ~o 121C,); 3-methyl-2-oxa~
zolldon0 (melting polnt 15~9Ca) ~ Dialkyl ~ulfamic acid halides: e.g.~ dimRthyl :-; ~ ~ulfamyl chloride (boiling point 80C. at 16 mmO) Alkyl~halosulfonates: e.g.g ethyl chlorosulfonate ; :(boiling point 151C~) :
:20 Unsaturated he~erocyc~ic carbo~ylic acid halides:
~ e.g., 2~furoy1 chloride ~7iquid range -2 to 173C.) `: Flve-membered unsat~rated heterosyclics: e.g., .~ : ' -3 9 5~dimethylisoxazole ~boiling po~nt 140G.);
1 methylpyrrole (boiling point 114Co);
294-dimethylthiazole (boiling point 1~4C.);
uran ~liquid range -85065 to 31.36C~) 11 .
. , ~
~ f~S;~ 11280 Esters and/or halides of dibasic carboxylic acid3:
e.gO, ethyl oxalyl chloride (boiling point 135C.) Mixed alkyl sulfonic acid halides and carboxylic acid hali~es: e.g., chlorosulfonyl acetyl chloride (boiling point 98C. at 10 mm.) Dialkyl sulfoxides: e.g., dimethyl sulfoxide (liquid rsnge 18.4 to 189C.) - Dialkyl sulfates: e.g., dimethylsulfate (liquid range -31.75 to 188.5C.) Dialkyl sulfites: e.g.g dimethylsulfite (boiling ; point 126C.) Alkylene sulfites: e.g., ethylene glycol sulfi~e (liquid range -11 to 173C.) ~alogenated alkanes: eOgo ~ methylene chloride (liquid range -95 to 4~C.); 1,3-dichloro-propane (liquid range -99.5 to 120.4C.) Of the above, the preferred solvents are ; ~ulfolane; crotonitrile; nitrobenzene; tetrahydrofuran;
1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
~-~utyrolactone; ethylene glycol sulfite;
d~m~thylsulfite; d~methyl sulfoxide; and 1,1- and 1,2-dimethoxyethane. Of the preferred solven~s, the best are 8ul~01ane; 3-methyl-2-oxazolidone; propylene carbonate : ~ and 1,3-dioxolane because they appear more chemically inert to battery components and have wide liquid ranges, and especial~y because they permit highly efficient utilization o the ca~hode materials.
'.
12.
. ~ . - .. .
, . . .
~ Z 11280 Th~ ionizing solute for use in the inv~nt~on may be a ~imple or double salt or mixtures t~ereo~, which will produce an ionically-conducti~e solution when dissolved in one or more solventsO Preferred solutes are c~mplexes of inorganic or organic Lewis acids and inorganic ionizable salts. The only require-ments for utility are that the salts, whether simple or complex, be compatible with the solvent or solvents being employed and that they yield a solution which is suficiently ionically conductive. According to the Lewis or electronic concept of acids.and bases, many substances which contain no active hydrogen can act as acids or acceptors of electron doublets~ The ba~ic concept is set forth in the chemical literature (Journal of the Franklin Institute, Vol. 226 - July/
December 1938, pages 293-313 by Lewis~O
A uggested reaction mechanism for the manner in which these complexes function in a solvent is :.
described in detail in ~. S. Patent ~o. 3,542,602 ~0 wherein it 1s suggested that the complex or double salt ormed between the Lewis acid and the ionizable salt yields an entity which is more stable than either of the componen~s alone. . ~.
Typical Lewis acids suitable for use in the present invention include aluminum fluoride, aluminum br~mide9 alumlnum chloride, antlmony pentachloride9 zirconlum tetrachloride, phosphorus pentachloride, ' L3.
: ~ .. . . . . . .
boron fluoride, boron chloride and boron bromide, Ionizable salts useful in combination with the Lewis acids include lithium fluoride~ lithium chloride, lithium bromide, lithium sulfide, sodium fluoride, sodium chloride, sodium bromide, potassium fluoride, potassium chloride and potassium bromide.
It will be obvious to those skilled in the art that ~he double salts formed by a Lewis acid and an inorganic ionizable salt may be used as such or the individualcomponentsmay be added to the solvent separately to form the double salt or the resulting ions in situ.
One such double salt, for example9 is that fonmed by ~he combination o aluminum chloride and lithium chloride to yield lith;um aluminum tetrachloride.
3rief Description of the Drawings Figure 1 is a cur~e showing the discharge I
characteristics of a non aqueous lead oxide-lithium cell employing a lead dioxide ~ositive electrode (cathode).
Figure 2 is a curve showing the discharge characteristics of a non-aqueous lead oxide-lithium cell employing a lead monoxide positive electrode.
Figure 3 is a curve showing the discharge characteristics of a non-aqueous lead oxide-lithium cell employing a lead dioxide positive electrode and having a layer of Lead powder interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said positi~e electrode in accordance with the present invention.
:
14.
5~ ll280 Figure 4 is a curve showing the discharge characteristics o a non-aqueous lead oxide~ hium cell employing a lead dioxide positive electrode and having a layer of lead monoxide interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said electrode in accordance with the present invention, Figure 5 is a curv~ showing the discharge - characteristics of a non-aqueous lead oxide~ hium cell employing a lead dioxide positive electrode and ha~ing a layer of lead particles interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said electrode in accordance with the present invention.
Figure 6 is a curve showing the discharge char~cteristics of a non-aqueous lead oxide-lithium cell employing a lead dioxide positive eLectrode and having a layer of lead monoxide interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said positive electrode in ~ccordance with the present invention.
EXAMPTE I
A flat-type cell was constructed utilizing a nickel metal base having therein a l-inch diameter shallow depression into which the cell contents were placed and over which a nickel metal cap was placed to close the cell~ The rontent~ o~ the cell consisted o~ ~ive sheets o lithi-~ foil having a total thickness of 0.10 inch9 about 4 ml of an electrolyte9 two porous non~woven polypropylene separators (0.005 inch th~ck each) . .
.: ....
15.
B~
which absorbed some of the electrolyte, and a lead dioxide cathode mix.
The electrolyte was a lM LiC104 in 77 volume per cent dioxolane, 23 volume per cent dimethoxyethane (D~E) with a trace of about 0.1 volume per cent dimethyl isoxazole (DMI) as a polymerization inhibitor. The cathode was pressed layer of 4.3 grams of lead dioxide.
The cell was discharged across a cons~ant load on a 3 milliamperedrain and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 1. Also observed and as recorded on ; Figure 1 is the open circuit voltage of the celI which was 3.5 volts. As is apparent from the curve in Figure 1, it took approximately four days before the voltage decreased to a substantially unipotential level of : approximately 1.2 ~olts. ~Iowe~er, many cell and battery powered devices which require an egsentially unipotential power source could not use this type of cell system because of its significant dual voltage level discharge charac-~eristic. :
: EXAMPLE II
.
: A flat~type cell was constructed using the same :~ : components as described in Example I except that the .
.:
~` : cathode mix was a compressed layer of a mixture of 3 grams : .
-~` of lead monoxide and 0.5 gram of carbon black added for : conductivity. As in Example I, the cathode mix was placed into the shallow depres~ioD in a nickel metal base along 16.
.
~59~
112~0 with the o~her cell components.
The cell was discharged on a 3-milliampere drain and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 2.
Also observed and as recorded on Figure 2 is the open circuit voltage of the cell which was about 3.2 volts.
This high open circuit voltage for the cell is believed to be due to the presence of oxygen and/or oxides on the surface of the carbon black in the cathode mix.
As is apparent rom the curve in Figure 2, the substantially unipotential voltage level output of this cell makes it an admirable candidate as a power source for many cell and battery operated devicesO As ; stated above~ however, although this type of cell has the advantage of discharging at a substantially uni~
potential level~ it has ~he disadvantage of having a rather low capacity as compared ~o a cell employing lead dioxide as the cathode material~
: :: EXAMPLE III
A flat-type cell was constructed using the :
same components as described in Example I except that the cathode was prepared in the ollowing manner:
.. ..
1.67 grams of lead dioxide powder (about 90 per cent by weight) weremixed with 5 per cent poly~etra- :
fluorethylene and 5 per cent acetylene black and then molded into a cohesive disc formO A thin layer of lead powder, sized 0.0737 mm, was thereafter coated on both ` 17.
, , . . . .
. .
~ ~ 8 ~ ~ 5 Z 11280 sides of the lead dioxide electrode and the coated electrode was then placed into the shallow depression in a nickel metal base as described in Example I.
The cell made in accordance with this inven-tion was discharged across a lK-ohm load (about 1.3 milliampere drain) and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 3. Also observed and as recorded in Figure 3 is the open circuit voltage o the cell which was about 208 volts.
As is apparent ~rom the curve in Figure 3, the output voltage of this cell continued at the sub-stantially unipotential level of lead monoxide-lithium for the major portion of its u~eful life. Thus using the teachings of this invention, a non-aqueous lead : dioxide cell can be made which takes advantage of the : ~ high capacity characteris~ic of lead dioxide while : simultaneously substantially eliminating the disadvantage : of the dual voltage level output characteristic of:~ .
lead dioxide in a non-aqueous cell system.
E~AMPLE IV
A flat-type cell was constructed using the ame component-s as described in Example I except that the cathode was prepared in the following manner:
:~ 1.5 grams of lead dioxide powder (about 85 ~ -per cent by weight) weremixed with 10 per cent polytetra : fluorethylene and 5 per cent carbon bLack and then molded 180 .
into a cohesive disc form. Before placing the elec~rode into a nickel me~al base as described in Example I, a thin layer of lead monoxide, 1.9 grams in weight, was placed between the inner surface of the shallow depression in the nickel metal base cathode collector and the lead dioxide electrode.
The cell so produced in accordance with this invention was then discharged across a 300-ohm load (about 4.3 milliampere drain) and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 4. Also observed and as recorded in Figure 4 is the open circuit voltage of the cell which was about 1.65 vol~s.
- As is apparent from the curve in Figure 4, the cell discharged at a substantially unipo~ential level almost immediately and then continued to discharge at the lead monoxide-lithium voltage level for more than 6 daysO Thus using the teachings of this invention, a non-aqueous lead dioxide cell can be made which takes 2G advantage of the high capacity characteris~ic of lead dioxide while simultaneously effectively eliminating the disadvantage of the dual voltage level output charac~
; teristic of lead dioxide in a non-aqueous cell system~
EXAMPLE V
A flat-type cell was constructed using the same components as described in Example I except that the positive electrode consisted of two electrodes. The ,:.. 19. '~ .
first electrode, ~ade of 2.8 grams of lead dioxide (about 92 per cent by weight) mixed with 3 per cent polytetrafluorethylene and 5 per cent partially oxidized lead powder, was compressed onto an expanded nickel mesh. The second electrode, made of 3.5 grams of lead monoxide (about 92.5 per cent by weight) mixed with 7.5 per cent polytetrafluorethylene, was compressed onto a polypropylene mesh. The lead monoxide electrode was placed into the shallow depression of a nickel base 1.
followed by the lead dioxide electrode so that the lead monoxide layered electrode was interposed between the lead dioxide electrode and the inner surface of the depression in the nickel base.
The cell so produced in accordance with this invention was then discharged across a 300-ohm load (about 3.7 milliampere drain) and the voltage observed as a f~nction of time is shown plotted as the curve on ~he graph in Figure 5. Also observed and as recorded on Figure 5 is the open circuit voltage of the cell which wa~ about 2.8 volts.
' : ' As is apparent from the curve in Figure 5, the cell discharged at a substantially unipotential level immediately and then continued at the lead monoxide-: lithium voltage level for more than 14 days. Thus using : the teachings of this invention, a non-aqueous lead dioxide cell can be made which takes advantage of the high capacity characteristic of lead dioxide while . 20.
simultaneously effectively eliminating the disadvantage of the dual voltage level output characteristic o~
l~ad dioxide in a non-aqueous cell system.
EXAMPLE VI
A flat-type cell was constructed as described in Example I, using the same type lithium anode foil and separators. The electrolyte for the cell was lM LiCF3S03 in 50 vol. % dioxolane - 50 vol. % dimethoxy- -ethane. The positive electrode was prepared as follows:
1.5 grams of a mixture of 9~.5 per cent lead monoxide and 7~5 per cent poly~etrafluorethylene were molded onto an expanded nic~el mesh. Next~ 1.5 grams ;
of a mixture of 92 per cent lead dioxide, 3 per cent polytetrafluorethylene and 5 per cent partially oxidized lead powder were molded on top of the lead monoxide layer) followed by a third layer of 1.5 grams of the ' same lead dloxide mixture compressed on top of the pre-vious layersO The layered positive electrode was then inserted into the shallow depression in a nickel base with the lead monoxide layer disposed ad~acent the inner surface of the shallow depression.
The cell was discharged on a 4-milliampere . . ,:
~ drain and the voltagP observed as a function of time , is shown plotted as the curve on the graph in Figure 6.
Also observed and as recorded on Figure 6 is the open circuit voltage of the cell which was about 3 vol~s.
As is apparent from the curve in Figure 6, ' , ' ' , ,' ', ' ,' " ., 3~
the cell discharged at a subs~antially unipotential level throughout. Thus using the teachings o~ this invention, a non~aqueous lead dioxide cell can be made which takes advantage of the high capacity characteristic of lead dioxide, while simultaneously effectively eliminating the disadvantage of the dual voltage level output characteristic of lead dioxide in a non-aqueous cell system.
EXAMPLE VII
10Several flat-type cells were constructed as described in Example VI using the same cell components except the electrolyte was as shown in the Table. The ; current density, the apparent cathode efficiency, and energy density for each cell were calculated. The data so obtain~d are also sho~n in ehe Table.
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: ~ ~ 23.
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112~0 As is apparent from the data shown in the Table, efficient non-aqueous lead dioxide cell can be made using the teachings of the subject invention, It is to be understood that other modifi-cations and changes to the preferred embodiments of the invention herein shown and described can al~o be made withuut departing from the spirit and scope of the invention.
~ ; ' : :, ~ ~ , -:
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.
Back~round of the Invention 10- The development of high energy cell systems requires the compatibility of an electrolyte possessing desirable electrochemical properties with highly active anode ma~erials, such as lithium, calcium, sodium and the like~ and the efficient use of high energy density : ~ .:
~ cathode materials,~such as FeS2, Co304, PbO2 and the ~ -. .
~ ~ lik~. The use of aqueous electrolytes is precluded in -.
these systems since the anode materials are sufficiently active to react wîth water chemically. Therefore, in ; order to reslize the high energy density obtainable through ~ use of these highly reactive anodes and high energy density cathodes, it is necessary to use a non-aqueous ~: .
; ele trolyte system.
..
~ One of the major disadvantages of employing lead .
~ dioxide (PbO2) as ehe active cathode material in a non-.
aqueous electrolyte system i9 that it will discharge at two different potentials. The first ~tep in the discharge ~: : :: : : curve is attributed to the reduction of the lead dioxide .
.. . .
~ 2-.
~0~ lSZ
to lead monoxide, while the second step is attributed to the reduction of the reaction product, lead monoxideO
Contrary to lead dioxide, lead monoxide will discharge in a non-aqueous cell system at a unipotential level.
One advantage in employing lead dioxide as the cathode material over lead monoxide is that it has almost double the capacity o~ lead monoxide. Thus in a non-aqueous electrolyte systemj lead monoxide will have the ad~antage of discharging at a unipotential plateau with the disadvantage of having a relatively low capacity while ~-lead dio~ide will ha~e the advantage of having a relatively high capacity with the disadvantage of dis-charging at two distinct voltage plateaus.
Many cell or battery applications, particularly in transistorized devices such as hearing aids, watches ~
and the like, require a substantial unipotential dis- -charge source for proper operation and, therefore, cannot use the dual voltage level discharge which is character-:: :
istic of non-aqueous lead dioxide cells. This dual ; 20 voltage level discharge characteristic is similar to the ~:: :: : , dual ~oltage discharge characteristic of aqueous alkaline divalent s~ilver oxide celle,~ Although many approaches have~been proposed for obtaining a unipotentia} discharge fr~m an aqueous alkaline divalent silver oxide cell, the approaches are not needed when iead dioxide is employed in an aqueous electrolyte cell system. Specifically~ in 3.
~:, ~Lo~
an aqueous electrolyte cell system, lead dioxide will dis-charge almos~ entirely at i~s higher voltage level so that, in effect, the cell will produce a substantially uni-potentlal discharge over the useful life of ~he cell.
Contrary to this, when lead dioxide is used as the cathode material in a non-aqueous eleotrolyte system, the cell will discharge at a first potential for a significant timeperiod and then decrease to a distinct lower potential for the remaincter of the discharge. A problem usually encountered in various cell systems Is that although an electrode-couple can function in an aqueous electrolyte, it is prac~ically impossible to predict in advance how well, if at all, it will function in a non-aqueous electrolyte.
Thus a cell must be considered as a unit having three parts - a cathode, an anode and an electrolyte - and it is to be understood that the parts of one cell may not be predictab b interchangeable with parts of another cell ~ -to produce an efficient and workable cell.
French Patent 2,288,401, published on June 18, 1976 (counterpart to German application 2,545,498 published on April 27, 1976), discloses a non-aqueous cell which employs a negative electrode, such as lithium7 a non-aqueous-sol~ent electrolyte and a positive active electrode consisting of a positive active m~terial of the oxides and oxidizing salts, the discharged reduction of which leads .
~. .
to metals of ~he group including lead, tin, gold, bismuth, zinc~ cadmium and their alloys and an electronic conductor consis~ing at least on the surface o~ a material selected from the group including lead, tin, gold, bismuth, zinc, cadmium and their alloysO Several examples are disclosed in this reference in which lead monoxide is employed as the positive acti~e material and lead9 tin or graphite is employed as ~he electronic conductor. Although this reference teaches one means for ob~aining a unipotential discharge for certain non-aqueous cell systems, as, for example, a cell employing lead monoxide as the positive ac~ive material~ the subject invention is directed to the use of lead dioxide as a positive electrode in a non-aqueous system and wherein a layer of lead and/or lead mon-oxide is interposed between the positive lead dioxide electrode and the inner surface of a conductive container housing said electrode.
: U. S. Patents 3,615,858 and 3,655,450 disclose batteries composed of a principal active ma~erial and a secondary active material and constructed such that the dis-charge of the principal active material is through the secondary active material so as to achieve the discharge potential characteristics of the secondary active material.
: Although the electrolyte for use in the disclosed cells in these reference~ is not specifically recited, the examples in the references all employ an aqueous elec-trolyte system. In U. S. Patent 3,6159858, it states 5.
- . . - .
. ~ . . .
112~0 tha~ divalent silver oxide can be discharged at the potential of lead dioxide. Contrary to this, the subject invention is directed to a cell which employs a lead dioxide positive electrode in a non~aqueous cell system and wherein a layer of lead and/or lead monoxide is interposed be~ween the positive lead dioxide electrode and the inner surface of a conductive container housing said electrode so that ~he cell can be effectively dis-charged at a su~stantially unipotential level over the useful life of the cell.
Accordingly, it is the primary object of this invention to provide a non-aqueous lead oxide cell which employs a lead dioxide positive electrode which is separated or isolated from the inner surface of a con-ductive container housing said elec~rode by a layer of lead and/or lead monoxide and which has a substantially unipoten~ial discharge voltage.
Another object of this invention is to provide a non-aqueous lead oxide cell which employs a lithium Z0 anode and a lead dioxide positive electrode, said positive electrode being separated from the inner surface of a conductive ontainer housing said electrode by a layer of lead and/or lead ~onoxide, and which cell has a substan-tially unipotential discharge.
~D~U~ ' ' The invention relates to a non-aqueous lead dioxide cell having a negative electrode, a positive &.
11~80 electrode comprising lead dioxide and an electrolyte housed within a conductive container; a layer of lead monoxide and/or lead interposed between~ and electrically and physically in con~ac~ with, said posl~ive electrode and the inner surface of the conduc~ive container; and said cell having a substantially unipotential discharge voltage.
A unipotential discharge voltage shall mean a relatively constant voltage level extending over at least 85 per cent of a cell's discharge capacity when discharged across a fixed load~ and wherein the voltage varies no more than + 10 per cent of the average voltage of said voltage levelO For example, a unipotential dischargP level can be represented by a voltage-time curve substan~ially free fr~m voltage excursions or steps during at leas~ 85 per cent of the time of di~charge across a con~tant load, such steps or exeursions being deined a~ vol~age reading~ outside of ~ 10 per cent o~
the average vol~age over the said 85 per cent portion of the time of discharge. Accordingly, it is the objec~ of this invention to effectively eliminate or effectively suppress the portion o the curve to the left o~ point A to yield a unipotential discharge level ~ -as generally shown by the curve between points A and B.
It is also within the ~cope of this invention to add a binder, an electronically conductive material, an eleo~rolyte-absorben~ ma~erial or mixtures thereof to .. . . .
the posi~ive electrode of this invention.
The lead monoxide layer and/or lead layer for use in this inventlon be~ween the lead dioxide electrode and ~he inner surface of the conductive container housing the electrode should be sufficient to substantially isolate or separate the positive electrode from the inner surface of the container such that the lead and/or - -lead monoxide layer will bP the main electronic path through which the lead dioxide discharges.
Preferably, the lead and/or lead monoxide layer should be the sole electronic path through which discharge of the lead dioxide electrode occursO The lead monoxide layer and/or lead layer should be sufficient in thickness to substantially eliminate the two voltage plateau discharge characteristic of lead dioxide in a non-aqueous electrolyte cell systemO A lead monoxide layer is preferable to a lead layer because lead monoxide ~ will contribute to the discharge capacity of t~e cell.
; Useful highly active negative metal anode --materials are generally consumable metals and include aluminum, the alkali metals, alkaline earth metals and alloys of alkali metals or alkaline earth metals with each other and other metals. The term "alloy" as used herein and in the appended claims is intended to include mi~tures 3 solid solutions, such as lithium-magnesium, and intermetallic compounds, such at lithium monoaluminide.
~' 8.
.. . .
The preferred anode materials are lithium, sodium, potassium, calcium and alloys th~reof.
Useful organic solvents employed alone or mixed with one or more other solvents for use in this invention include the ollowing classes of compounds:
Alkylenenitriles: e.g., crotonitrile (liquid range -51.1C. to 120C.) Trialkyl bora~es: eOg~9 trimethyl borate, (CH30)3B.
~ uid range -2903 to 67C~) ~etraa~kyl ~llica~es: e.g~ tetramethyl silicate, (CH3~)4Si (boiling point 127C~) .~ , Nitroalkanes: e ~ g ., nltrome~hane, CH3~02 ~liqllid range 17 to 100.8CO) A~lcylnitrlles: e,g., acetonitrile5 CH3CN
(~quid ~angc ~45 to 81.6C.) : Dialkylamides: e.g" dime~hylformamide, HCON(CE~3)2 (l~quid range -60.48 to 149C.) Lactam~: eOg~ ~ N-methylpyrro:Lidone, CH2~:H2~CH2~::0-N-GH3 (liquid range 76 to 202C~) 20 Tetraa~Xylureas: eO go 7 tetramethylurea, (CH3~2N~O-N~SH3) 2 (li~uld range -1~ 2 to 166C
Monocarboxylic acld esters: e.gO ~ ethyl acetate ~liquid range 83.6 to 77.06C.~ ~
:, ' .
- . ~ .
112~0 Orthoester~: e,g., trimethylorthoformate, HC (OCH3)3 - (boiling po~nt 103C.) r - , Lactones: e.g., ~f~amma)butyrolactone, CH2dCH2-CH2-0-CO
: (liquld range -42 to 206Co) D~alkyl carbonates: e.g" dimethyl carbonate, OC(OCH3)2 (liquid range 2 to 90C.) Al~ylene carbonates: e~g., propylene carbonate, CH(CH3)CH2~0-C0-0 (liquid range -48 to 242C.) M~noether~: e.g., die~hyl ether (llquid range -116 ~o 3405C.) Polyethers: e.g.g 1,1- and 19 2-dimethoxyethane ..
~liquid ranges -113~2 to 64,~C9 and -58 to 83C~, respectively) Cyclic ethers: e.g., t~trahydrofuran (liquid range -65 to 67~C.); 1~3-dioxolane (liquid range ~ _95 tO 78Co~
Nitroaromatic~: e.g" nitrobenæene (liquid range 5,7 to 2~008C.) Aromatic carboxylic acid halides: e,g. 9 benzoyl :; 20 chloride (liquid range 0 to 197C.); benzoyl : . bromide tllquid range _7& to 218Co~
Aroma~ic sulfonic acid halides: e.g., benzene sulfonyl : chloride (~iquid range 14.5 to 251C~) Aroma~ic pho~phonic acid dih~lides: e~g.g benzene . phosphonyl dichloride (boiling polnt 258C.) .
10.
5~
Aromatic thiophosphonic acid dihalides: e~gO ~
benzene thiopho~phonyl dichloride (boiling point 124C. at 5 mm~ ) ' Cyclic sulfones: e.gO 3 ~ulfolane, H2 H2-CH2-CH2-S02 (m~lting point 22C.);
3-methylsulfolane (melting point -1C.) A~kyl sulfonic acid halides: e.g., methanesulfonyl chloride (boi7ing point 161C.) Alkyl carboxylic acid halides: e.g.9 acetyl chloride - 10 (liquid range -~12 to 50~9Co); acetyl br ide uid range -96 to 76.C.~ propionyl chloride (liquid range ~94 to 80~..) Saturated heterocyelics: eOg~, tetrahydrothiophene (llquid rang~ -96 ~o 121C,); 3-methyl-2-oxa~
zolldon0 (melting polnt 15~9Ca) ~ Dialkyl ~ulfamic acid halides: e.g.~ dimRthyl :-; ~ ~ulfamyl chloride (boiling point 80C. at 16 mmO) Alkyl~halosulfonates: e.g.g ethyl chlorosulfonate ; :(boiling point 151C~) :
:20 Unsaturated he~erocyc~ic carbo~ylic acid halides:
~ e.g., 2~furoy1 chloride ~7iquid range -2 to 173C.) `: Flve-membered unsat~rated heterosyclics: e.g., .~ : ' -3 9 5~dimethylisoxazole ~boiling po~nt 140G.);
1 methylpyrrole (boiling point 114Co);
294-dimethylthiazole (boiling point 1~4C.);
uran ~liquid range -85065 to 31.36C~) 11 .
. , ~
~ f~S;~ 11280 Esters and/or halides of dibasic carboxylic acid3:
e.gO, ethyl oxalyl chloride (boiling point 135C.) Mixed alkyl sulfonic acid halides and carboxylic acid hali~es: e.g., chlorosulfonyl acetyl chloride (boiling point 98C. at 10 mm.) Dialkyl sulfoxides: e.g., dimethyl sulfoxide (liquid rsnge 18.4 to 189C.) - Dialkyl sulfates: e.g., dimethylsulfate (liquid range -31.75 to 188.5C.) Dialkyl sulfites: e.g.g dimethylsulfite (boiling ; point 126C.) Alkylene sulfites: e.g., ethylene glycol sulfi~e (liquid range -11 to 173C.) ~alogenated alkanes: eOgo ~ methylene chloride (liquid range -95 to 4~C.); 1,3-dichloro-propane (liquid range -99.5 to 120.4C.) Of the above, the preferred solvents are ; ~ulfolane; crotonitrile; nitrobenzene; tetrahydrofuran;
1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
~-~utyrolactone; ethylene glycol sulfite;
d~m~thylsulfite; d~methyl sulfoxide; and 1,1- and 1,2-dimethoxyethane. Of the preferred solven~s, the best are 8ul~01ane; 3-methyl-2-oxazolidone; propylene carbonate : ~ and 1,3-dioxolane because they appear more chemically inert to battery components and have wide liquid ranges, and especial~y because they permit highly efficient utilization o the ca~hode materials.
'.
12.
. ~ . - .. .
, . . .
~ Z 11280 Th~ ionizing solute for use in the inv~nt~on may be a ~imple or double salt or mixtures t~ereo~, which will produce an ionically-conducti~e solution when dissolved in one or more solventsO Preferred solutes are c~mplexes of inorganic or organic Lewis acids and inorganic ionizable salts. The only require-ments for utility are that the salts, whether simple or complex, be compatible with the solvent or solvents being employed and that they yield a solution which is suficiently ionically conductive. According to the Lewis or electronic concept of acids.and bases, many substances which contain no active hydrogen can act as acids or acceptors of electron doublets~ The ba~ic concept is set forth in the chemical literature (Journal of the Franklin Institute, Vol. 226 - July/
December 1938, pages 293-313 by Lewis~O
A uggested reaction mechanism for the manner in which these complexes function in a solvent is :.
described in detail in ~. S. Patent ~o. 3,542,602 ~0 wherein it 1s suggested that the complex or double salt ormed between the Lewis acid and the ionizable salt yields an entity which is more stable than either of the componen~s alone. . ~.
Typical Lewis acids suitable for use in the present invention include aluminum fluoride, aluminum br~mide9 alumlnum chloride, antlmony pentachloride9 zirconlum tetrachloride, phosphorus pentachloride, ' L3.
: ~ .. . . . . . .
boron fluoride, boron chloride and boron bromide, Ionizable salts useful in combination with the Lewis acids include lithium fluoride~ lithium chloride, lithium bromide, lithium sulfide, sodium fluoride, sodium chloride, sodium bromide, potassium fluoride, potassium chloride and potassium bromide.
It will be obvious to those skilled in the art that ~he double salts formed by a Lewis acid and an inorganic ionizable salt may be used as such or the individualcomponentsmay be added to the solvent separately to form the double salt or the resulting ions in situ.
One such double salt, for example9 is that fonmed by ~he combination o aluminum chloride and lithium chloride to yield lith;um aluminum tetrachloride.
3rief Description of the Drawings Figure 1 is a cur~e showing the discharge I
characteristics of a non aqueous lead oxide-lithium cell employing a lead dioxide ~ositive electrode (cathode).
Figure 2 is a curve showing the discharge characteristics of a non-aqueous lead oxide-lithium cell employing a lead monoxide positive electrode.
Figure 3 is a curve showing the discharge characteristics of a non-aqueous lead oxide-lithium cell employing a lead dioxide positive electrode and having a layer of Lead powder interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said positi~e electrode in accordance with the present invention.
:
14.
5~ ll280 Figure 4 is a curve showing the discharge characteristics o a non-aqueous lead oxide~ hium cell employing a lead dioxide positive electrode and having a layer of lead monoxide interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said electrode in accordance with the present invention, Figure 5 is a curv~ showing the discharge - characteristics of a non-aqueous lead oxide~ hium cell employing a lead dioxide positive electrode and ha~ing a layer of lead particles interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said electrode in accordance with the present invention.
Figure 6 is a curve showing the discharge char~cteristics of a non-aqueous lead oxide-lithium cell employing a lead dioxide positive eLectrode and having a layer of lead monoxide interposed substantially between the lead dioxide positive electrode and the inner surface of a conductive container housing said positive electrode in ~ccordance with the present invention.
EXAMPTE I
A flat-type cell was constructed utilizing a nickel metal base having therein a l-inch diameter shallow depression into which the cell contents were placed and over which a nickel metal cap was placed to close the cell~ The rontent~ o~ the cell consisted o~ ~ive sheets o lithi-~ foil having a total thickness of 0.10 inch9 about 4 ml of an electrolyte9 two porous non~woven polypropylene separators (0.005 inch th~ck each) . .
.: ....
15.
B~
which absorbed some of the electrolyte, and a lead dioxide cathode mix.
The electrolyte was a lM LiC104 in 77 volume per cent dioxolane, 23 volume per cent dimethoxyethane (D~E) with a trace of about 0.1 volume per cent dimethyl isoxazole (DMI) as a polymerization inhibitor. The cathode was pressed layer of 4.3 grams of lead dioxide.
The cell was discharged across a cons~ant load on a 3 milliamperedrain and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 1. Also observed and as recorded on ; Figure 1 is the open circuit voltage of the celI which was 3.5 volts. As is apparent from the curve in Figure 1, it took approximately four days before the voltage decreased to a substantially unipotential level of : approximately 1.2 ~olts. ~Iowe~er, many cell and battery powered devices which require an egsentially unipotential power source could not use this type of cell system because of its significant dual voltage level discharge charac-~eristic. :
: EXAMPLE II
.
: A flat~type cell was constructed using the same :~ : components as described in Example I except that the .
.:
~` : cathode mix was a compressed layer of a mixture of 3 grams : .
-~` of lead monoxide and 0.5 gram of carbon black added for : conductivity. As in Example I, the cathode mix was placed into the shallow depres~ioD in a nickel metal base along 16.
.
~59~
112~0 with the o~her cell components.
The cell was discharged on a 3-milliampere drain and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 2.
Also observed and as recorded on Figure 2 is the open circuit voltage of the cell which was about 3.2 volts.
This high open circuit voltage for the cell is believed to be due to the presence of oxygen and/or oxides on the surface of the carbon black in the cathode mix.
As is apparent rom the curve in Figure 2, the substantially unipotential voltage level output of this cell makes it an admirable candidate as a power source for many cell and battery operated devicesO As ; stated above~ however, although this type of cell has the advantage of discharging at a substantially uni~
potential level~ it has ~he disadvantage of having a rather low capacity as compared ~o a cell employing lead dioxide as the cathode material~
: :: EXAMPLE III
A flat-type cell was constructed using the :
same components as described in Example I except that the cathode was prepared in the ollowing manner:
.. ..
1.67 grams of lead dioxide powder (about 90 per cent by weight) weremixed with 5 per cent poly~etra- :
fluorethylene and 5 per cent acetylene black and then molded into a cohesive disc formO A thin layer of lead powder, sized 0.0737 mm, was thereafter coated on both ` 17.
, , . . . .
. .
~ ~ 8 ~ ~ 5 Z 11280 sides of the lead dioxide electrode and the coated electrode was then placed into the shallow depression in a nickel metal base as described in Example I.
The cell made in accordance with this inven-tion was discharged across a lK-ohm load (about 1.3 milliampere drain) and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 3. Also observed and as recorded in Figure 3 is the open circuit voltage o the cell which was about 208 volts.
As is apparent ~rom the curve in Figure 3, the output voltage of this cell continued at the sub-stantially unipotential level of lead monoxide-lithium for the major portion of its u~eful life. Thus using the teachings of this invention, a non-aqueous lead : dioxide cell can be made which takes advantage of the : ~ high capacity characteris~ic of lead dioxide while : simultaneously substantially eliminating the disadvantage : of the dual voltage level output characteristic of:~ .
lead dioxide in a non-aqueous cell system.
E~AMPLE IV
A flat-type cell was constructed using the ame component-s as described in Example I except that the cathode was prepared in the following manner:
:~ 1.5 grams of lead dioxide powder (about 85 ~ -per cent by weight) weremixed with 10 per cent polytetra : fluorethylene and 5 per cent carbon bLack and then molded 180 .
into a cohesive disc form. Before placing the elec~rode into a nickel me~al base as described in Example I, a thin layer of lead monoxide, 1.9 grams in weight, was placed between the inner surface of the shallow depression in the nickel metal base cathode collector and the lead dioxide electrode.
The cell so produced in accordance with this invention was then discharged across a 300-ohm load (about 4.3 milliampere drain) and the voltage observed as a function of time is shown plotted as the curve on the graph in Figure 4. Also observed and as recorded in Figure 4 is the open circuit voltage of the cell which was about 1.65 vol~s.
- As is apparent from the curve in Figure 4, the cell discharged at a substantially unipo~ential level almost immediately and then continued to discharge at the lead monoxide-lithium voltage level for more than 6 daysO Thus using the teachings of this invention, a non-aqueous lead dioxide cell can be made which takes 2G advantage of the high capacity characteris~ic of lead dioxide while simultaneously effectively eliminating the disadvantage of the dual voltage level output charac~
; teristic of lead dioxide in a non-aqueous cell system~
EXAMPLE V
A flat-type cell was constructed using the same components as described in Example I except that the positive electrode consisted of two electrodes. The ,:.. 19. '~ .
first electrode, ~ade of 2.8 grams of lead dioxide (about 92 per cent by weight) mixed with 3 per cent polytetrafluorethylene and 5 per cent partially oxidized lead powder, was compressed onto an expanded nickel mesh. The second electrode, made of 3.5 grams of lead monoxide (about 92.5 per cent by weight) mixed with 7.5 per cent polytetrafluorethylene, was compressed onto a polypropylene mesh. The lead monoxide electrode was placed into the shallow depression of a nickel base 1.
followed by the lead dioxide electrode so that the lead monoxide layered electrode was interposed between the lead dioxide electrode and the inner surface of the depression in the nickel base.
The cell so produced in accordance with this invention was then discharged across a 300-ohm load (about 3.7 milliampere drain) and the voltage observed as a f~nction of time is shown plotted as the curve on ~he graph in Figure 5. Also observed and as recorded on Figure 5 is the open circuit voltage of the cell which wa~ about 2.8 volts.
' : ' As is apparent from the curve in Figure 5, the cell discharged at a substantially unipotential level immediately and then continued at the lead monoxide-: lithium voltage level for more than 14 days. Thus using : the teachings of this invention, a non-aqueous lead dioxide cell can be made which takes advantage of the high capacity characteristic of lead dioxide while . 20.
simultaneously effectively eliminating the disadvantage of the dual voltage level output characteristic o~
l~ad dioxide in a non-aqueous cell system.
EXAMPLE VI
A flat-type cell was constructed as described in Example I, using the same type lithium anode foil and separators. The electrolyte for the cell was lM LiCF3S03 in 50 vol. % dioxolane - 50 vol. % dimethoxy- -ethane. The positive electrode was prepared as follows:
1.5 grams of a mixture of 9~.5 per cent lead monoxide and 7~5 per cent poly~etrafluorethylene were molded onto an expanded nic~el mesh. Next~ 1.5 grams ;
of a mixture of 92 per cent lead dioxide, 3 per cent polytetrafluorethylene and 5 per cent partially oxidized lead powder were molded on top of the lead monoxide layer) followed by a third layer of 1.5 grams of the ' same lead dloxide mixture compressed on top of the pre-vious layersO The layered positive electrode was then inserted into the shallow depression in a nickel base with the lead monoxide layer disposed ad~acent the inner surface of the shallow depression.
The cell was discharged on a 4-milliampere . . ,:
~ drain and the voltagP observed as a function of time , is shown plotted as the curve on the graph in Figure 6.
Also observed and as recorded on Figure 6 is the open circuit voltage of the cell which was about 3 vol~s.
As is apparent from the curve in Figure 6, ' , ' ' , ,' ', ' ,' " ., 3~
the cell discharged at a subs~antially unipotential level throughout. Thus using the teachings o~ this invention, a non~aqueous lead dioxide cell can be made which takes advantage of the high capacity characteristic of lead dioxide, while simultaneously effectively eliminating the disadvantage of the dual voltage level output characteristic of lead dioxide in a non-aqueous cell system.
EXAMPLE VII
10Several flat-type cells were constructed as described in Example VI using the same cell components except the electrolyte was as shown in the Table. The ; current density, the apparent cathode efficiency, and energy density for each cell were calculated. The data so obtain~d are also sho~n in ehe Table.
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112~0 As is apparent from the data shown in the Table, efficient non-aqueous lead dioxide cell can be made using the teachings of the subject invention, It is to be understood that other modifi-cations and changes to the preferred embodiments of the invention herein shown and described can al~o be made withuut departing from the spirit and scope of the invention.
~ ; ' : :, ~ ~ , -:
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.
Claims (24)
1. A non-aqueous lead oxide cell comprising a highly active metal negative electorde, a positive elec-trode comprising lead dioxide and a non-aqueous electrolyte comprising a salt dissolved in an organic solvent housed within a conductive container; a layer of lead monoxide interposed between, and electrically and physically in contact with, said positive electrode and the inner sur-face of the conductive container; and said cell having a substantially unipotential discharge voltage.
2. The lead oxide cell of claim 1 wherein the lead monoxide layer is the sole electronic path between the lead dioxide positive electrode and the inner surface of the conductive container.
3. The lead oxide cell of claim 1 wherein the active metal negative electrode is selected from the group consisting of aluminum, the alkali metals, the alkaline earth metals and alloys thereof.
4. The lead oxide cell of claim 3 wherein the active metal negative electrode is selected from the group consisting of lithium, sodium, potassium, calcium and alloys thereof.
5. The lead oxide cell of claim 4 wherein the active metal negative electrode is lithium.
25.
25.
6. The lead oxide cell of claim 1 wherein the solute of the electrolyte is a complex salt of a Lewis acid and an inorganic ionizable salt.
7. The lead oxide cell of claim 1 wherein the solvent of the electrolyte is at least one solvent selected from the group consisting of sulfolane;
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
8. The lead oxide cell of claim 7 wherein said at least one solvent is selected from the group consisting of sulfolane; 3-methyl-2-oxazolidone; propylene carbonate;
1,3-dioxolane; and dimethoxyethane.
1,3-dioxolane; and dimethoxyethane.
9. A non-aqueous lead oxide cell comprising a highly active metal negative electrode, a positive electrode comprising lead dioxide; and an non-aqueous electrolyte comprising a salt dissolved in an organic solvent housed within a conductive container; a layer of lead interposed between, and electrically and physically in contact with, said positive electrode and the inner surface of the con-ductive container; and said cell having a substantially unipotential discharge voltage.
10. The lead oxide cell of claim 9 wherein 26.
the lead layer is the sole electronic path between the lead dioxide positive electrode and the inner surface of the conductive housing.
the lead layer is the sole electronic path between the lead dioxide positive electrode and the inner surface of the conductive housing.
11. The lead oxide cell of claim 9 wherein the active metal negative electrode is selected from the group consisting of aluminum, the alkali metals, the alkaline earth metals and alloys thereof.
12. The lead oxide cell of claim 11 wherein the active metal negative electrode is selected from the group consisting of lithium, sodium, potassium, calcium and alloys thereof.
13. The lead oxide cell of claim 12 wherein the active metal negative electrode is lithium.
14. The lead oxide cell of claim 9 wherein the solute of the electrolyte is a complex salt of a Lewis acid and an inorganic ionizable salt.
15. The lead oxide cell of claim 9 wherein the solvent of the electrolyte is at least one solvent selected from the group consisting of sulfolane;
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
27.
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
27.
16. The lead oxide cell of claim 15 wherein said at least one solvent is selected from the group consisting of sulfolane; 3-methyl-2-oxazolidone; propylene carbonate; 1,3-dioxolane; and dimethoxyethane.
17. A non-aqueous lead oxide cell comprising a highly active metal negative electrode, a positive electrode comprising lead dioxide and a non-aqueous electrolyte comprising a salt dissolved in an organic solvent housed within a conductive container; a layer of lead and lead monoxide interposed between, and elec-trically and physically in contact with, said positive electrode and the inner surface of the conductive con-tainer; and said cell having a substantially unipotential discharge voltage.
18. The lead oxide cell of claim 17 wherein the lead and lead monoxide layer is the sole electronic path between the lead dioxide positive electrode and thee inner surface of the conductive container.
19. The lead oxide cell of claim 17 wherein the active metal negative electrode is selected from the group consisting of aluminum, the alkali metals, the alkaline earth metals and alloys thereof.
20. The lead oxide cell of claim 19 wherein the active metal negative electrode is selected from the group consisting of lithium, sodium, potassium, calcium and alloys thereof.
28.
28.
21. The lead oxide cell of claim 19 wherein the active metal negative electrode is lithium.
22. The lead oxide cell of claim 17 wherein the solute of the electrolyte is a complex salt of a Lewis acid and an inorganic ionizable salt.
230 The lead oxide cell of claim 17 wherein the solvent of the electrolyte is at least one solvent selected from the group consisting of sulfolane;
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
crotonitrile; nitrobenzene; tetrahydrofuran; 1,3-dioxolane; 3-methyl-2-oxazolidone; propylene carbonate;
?-butyrolactone; ethylene glycol sulfite; dimethyl-sulfite; dimethyl sulfoxide; 1,1- and 1,2-dimethoxy-ethane; and dimethyl isoxazole.
24. The lead oxide cell of claim 23 wherein said at least one solvent is selected from the group consisting of sulfolane; 3-methyl-2-oxazolidone;
propylene carbonate; 1,3 dioxolane; and dimethoxyethane.
29.
propylene carbonate; 1,3 dioxolane; and dimethoxyethane.
29.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US754,532 | 1976-12-27 | ||
| US05/754,532 US4048403A (en) | 1976-12-27 | 1976-12-27 | Non-aqueous lead dioxide cell having a unipotential discharge voltage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088152A true CA1088152A (en) | 1980-10-21 |
Family
ID=25035207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA293,225A Expired CA1088152A (en) | 1976-12-27 | 1977-12-16 | Non-aqueous lead dioxide cell having a unipotential discharge voltage |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US4048403A (en) |
| JP (2) | JPS5383027A (en) |
| AT (1) | AT361060B (en) |
| AU (1) | AU510792B2 (en) |
| BE (1) | BE862353A (en) |
| CA (1) | CA1088152A (en) |
| CH (1) | CH620052A5 (en) |
| DE (1) | DE2756927C3 (en) |
| FR (1) | FR2375728A1 (en) |
| GB (1) | GB1553044A (en) |
| NL (1) | NL7714369A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4163829A (en) * | 1977-11-14 | 1979-08-07 | Union Carbide Corporation | Metallic reducing additives for solid cathodes for use in nonaqueous cells |
| US4271244A (en) * | 1978-09-14 | 1981-06-02 | Saft-Societe Des Accumulateurs Fixes Et De Traction | High specific energy battery having an improved positive active material |
| JPS55119355A (en) * | 1979-03-07 | 1980-09-13 | Sanyo Electric Co Ltd | Non-aqueous electrolyte battery |
| FR2562330B1 (en) * | 1984-03-28 | 1987-02-27 | Accumulateurs Fixes | SPECIFIC HIGH-ENERGY ELECTROCHEMICAL GENERATOR WITH REDUCED INITIAL IMPEDANCE |
| US6291108B1 (en) * | 1989-12-12 | 2001-09-18 | Sanyo Electric Co., Ltd. | Non-aqueous electrolyte cell |
| CN1134083C (en) * | 1997-09-19 | 2004-01-07 | 三菱化学株式会社 | Nonaqueous electrolyte battery |
| US7947391B2 (en) * | 2004-01-13 | 2011-05-24 | Stauffer John E | Lead-alkaline battery |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1216394B (en) * | 1958-02-03 | 1966-05-12 | Yardney International Corp | Galvanic element with anhydrous electrolyte |
| DE1671745C3 (en) * | 1967-01-13 | 1979-01-25 | Esb Inc., Philadelphia, Pa. (V.St.A.) | Galvanic element and process for its production |
| JPS4921127B2 (en) * | 1971-09-02 | 1974-05-30 | ||
| JPS5549387B2 (en) * | 1972-03-23 | 1980-12-11 | ||
| US3877983A (en) * | 1973-05-14 | 1975-04-15 | Du Pont | Thin film polymer-bonded cathode |
| US3907597A (en) * | 1974-09-27 | 1975-09-23 | Union Carbide Corp | Nonaqueous cell having an electrolyte containing sulfolane or an alkyl-substituted derivative thereof |
-
1976
- 1976-12-27 US US05/754,532 patent/US4048403A/en not_active Expired - Lifetime
-
1977
- 1977-12-16 CA CA293,225A patent/CA1088152A/en not_active Expired
- 1977-12-21 DE DE2756927A patent/DE2756927C3/en not_active Expired
- 1977-12-23 FR FR7738960A patent/FR2375728A1/en active Granted
- 1977-12-23 GB GB53659/77A patent/GB1553044A/en not_active Expired
- 1977-12-23 NL NL7714369A patent/NL7714369A/xx active Search and Examination
- 1977-12-23 CH CH1600577A patent/CH620052A5/fr not_active IP Right Cessation
- 1977-12-23 AT AT928677A patent/AT361060B/en not_active IP Right Cessation
- 1977-12-23 AU AU31960/77A patent/AU510792B2/en not_active Expired
- 1977-12-26 JP JP15717977A patent/JPS5383027A/en active Pending
- 1977-12-27 BE BE183872A patent/BE862353A/en not_active IP Right Cessation
-
1983
- 1983-09-21 JP JP1983145111U patent/JPS59129168U/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE2756927A1 (en) | 1978-06-29 |
| BE862353A (en) | 1978-06-27 |
| GB1553044A (en) | 1979-09-19 |
| JPS5383027A (en) | 1978-07-22 |
| AT361060B (en) | 1981-02-25 |
| FR2375728A1 (en) | 1978-07-21 |
| JPS59129168U (en) | 1984-08-30 |
| DE2756927C3 (en) | 1981-08-27 |
| NL7714369A (en) | 1978-06-29 |
| CH620052A5 (en) | 1980-10-31 |
| FR2375728B1 (en) | 1983-05-27 |
| AU3196077A (en) | 1979-06-28 |
| US4048403A (en) | 1977-09-13 |
| AU510792B2 (en) | 1980-07-10 |
| ATA928677A (en) | 1980-07-15 |
| DE2756927B2 (en) | 1980-10-23 |
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