CA1053325A - Method of preparing high capacity nickel electrode powder - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An electrode plate is made by loading a supporting porous metallic plaque with active battery material made by:
(1) hydrolyzing the reaction product of a starting material comprising an admixture of Ni oxide and effective amounts of sodium peroxide fused at temperatures between about 800°C-1150°C, the hydrolyzed solid reaction product containing electrochemically active Ni hydrated oxides and hydroxide forms, (2) if desirable, drying the product below about 65°C, and (3) adding, at some step in the method, an amount of cobalt containing additive effective to provide about 2-12 wt% total Co in the active battery material based on Ni oxide plus Co content.

Description

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BACKGROUND OF TH~ I~ENTION
me fusion of metallic nickel with sodium dioxide was reported in 1896 by W~ L. Dudley in 18 J. Am. Chem. Soc.
901, Dudley fused sodium dioxide in a nickel crucible with nickel metal at a cherry-red heat, about 700-800C~ ~or about one hour. ~fter cooling, the contents were submerged in water. me formed brown crystals were then washed to : remove alkaliO The crystals were then dried at 110Co The crystals were analyxed and believed to be the dihydrate . Ni~04. 2H20~ with 0,7 wt~ cobalt as an impurity. A cobalto-cobaltic dihydrate Co~O~ . 2H20 is also described 2S obtained ~y exposing to moist air Co304~ prep~red by heating cobalt ; carbonate. These materials were believed to be new com~
pounds but no active battery material or electrochemical use was suggested~
Presently used methods for the preparation of .

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n~ckel active battery material involve chemical precipitation or electrochemical precipitation o~ divalent nickel (II) hydroxide, as taught ~or example by Fedu~ka et, al, in United States Patent 3,579,385 and Hardman in United States Patent 37600,227,. Faber, in Unlted State~ Patent ~,436,267, converted directly to trivalent ~i (III) hydroxide battery material~ by 100% oxidation of finely divided Ni (II) hydrox- ~;
ide powder in a gas ~tream containing ozone~ Xe then pa~ted this material into an electrode plaque.
me usual procedure in making a battery plate in-volves loading the dlvalent nic~el (II) hydroxide into a porou$ plaque, with o~ddation o~ the materl~l in the plaque to a form o~ trivalent nickel (III) hydroxide. This is accom-plished by electrochemical charging and di~charging "~orma-tion'l of the lo~ded plaque in an alkaline electrolyte, prio~r to introductlon of ~he plaque into a battery.
Ozone treatment in~olves a complex process u~ing expensive equlpment. Electro-precip~tation processes are also co~tly and represent a disproportionata sha~e o~ the raw . , materials expense in iro~-nickel batteries, while chemical preclpitation methods result ln gelatinous materi~ls which are di~icult to load into a conducting matrix.
Al~ three o~ these methods involve init1al pro-duction of nickel h~droxide. Chemical precipitation means high cost starting material~ precipitation, ~iltering, wash-ing, drying, grinding, etc., all o~ which make the cost of ths ~inal electrode powder high, Electro precipita~ on and ozone treatment involve major capital expenditureæ ~or hardware in addition to high costs ~or ~tarting materials.
With the increasing i~portance of improved batteries .. .. ... . . . . . . .

~(~S3325 a~ a clean power source, especially in the tran~portation area, there is a need ~or improved active materials, that will provide capacities closer to the theoretical limit ~han hereto~ore possible. To make the~e batteries commercially ~easible, the costs of active material manu~acture must be drast1cally reduced. What is ne~ded then is a method o~
making ine~penslve highly active m~terial~O
SUMMAR~ OF THE I~VENTIO~ ~
We ha~e discovered a process that will provide an ~ :
improved acti~ated battery material mlxture, by chemically reacting NiO, ~hich may also have added to lt about 2-12 wt%
Co based on NiO plus Co content as a material ~elected from Co, CoO, Co20~, Co304, or their mi~tures, with ef~ective amount~ o~ Na20 , generally within a wright ratio o~ Nio:Na202 of 1:I.35 to 1:2.1, Thls nickel oxide-~odium peroxide mixture is reacted at temperatures between about 800C-1150C, ~or a period of time, generally about 1/2 - 8 hours, ef~ectivs to form Na~iO2 or NaNiO2 plus NaCoO2 melted react~on product.
The reactlon product, comprising NaNiO2g ~s then hydrolyzed. I~ the cobalt oxide or elemental cobalt additive wa~ not added initlally, before fu~lon, as ls pre~erred, it will be added generally a~ cobalt hydroxide a~ter hydrolysisJ
or a~ a Water solubl~ oobalt salt such a~ cobalt chloride or cobalt nitrate during hydroly~is~ a~ter hydrolysis or a~ter plaque loading. . :
Thl8 process will provlde a final solid ~ctive .' batter~ mater1al containing over about 95 wt% solid Ni hydrated oxides and hydroxide ~orms and Co hgdroxide forms~
the remainder being i~terlaminar sodiumD It is ~mportant -3- ~:

- . . .

.` ~, that about 0~5 to 5 wt~ but pre~erably 0~5 to 3 wt% unreacted NaN102 be present a~ter hydrolysis and drylng. The unreacted NaNiO2 is present, in the active material as interlaminar sodium ln the nickel oxy-hydroxide layers and helps prevent swelling o~ the acti~e material in the plate durinæ the li~e of the battery.
mis actlvated bat~ery material i8 washed and gen-erally dried a~ter which ~t can ~hen be loaded into a sup-porting por~us plaque to provide an electrode plate~ which may then be electrochemicall~ cycled or "~ormea" (electrically charged and discharged in an alkaline electrolyte) prior to use in a battery oppo~ite a suitable negative electrode.
I~e d~ylng ~tep is generaily carriedoout at temperatures below about 65C, or at a suitable temperature in a high moisture atmosph~re ~o khat water present in the active material structure i~ not eliminated to an extent to cause ~ -th~ materlal to lose activity.
m iæ process involves ~onversion o~ nickel oxide, or nickel oxide with added cobalt a~ elemental cobalt or cobalt oxide to an active battery material powder without tedious Piltering or washing steps and without use o~ expen-~ive electrical equipment. m e ~tart,ing materials cost is signi~icantly reduced, since nickel oxlde ls the least exæensive nickel contalning material commercially available~
Starting with nickel oxide ma~es the proce~s u~e~ul and commercially feasible, since it eliminates a prolonged oxidation step at high temperatures ehich is sure to degrade the reaction ~ontainer, Starting material~ cost relati~e to the chemical, electrochemical and ozone processes is drasti-cally reduced by at lea~t 50~ In addltion, a by-produ~t o~

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thi~ process is an aqueou~ al~ali metal hydroxide solution which may be ~urther u~ed as a battery electrol~te by suitable ~.
processing, or used as a basic material for neutralizing mine acid pools and the l~ke.
BRIEF DESCRIPTION OF THE DRAWINS
For a better understandlng of the invention re~erence may be made to the pre~erred embodiments exemplary o~ the irlvention, ~hown in ~he accompanyir~g drawlng~ in which:
FIGURE 1 is a graph sho~ing the per~ormance o~ the .. ~ .
three Example 1 nickel electrode plate~, in term~ o~ ~apacit~
~ersu~ cycl~ number, in relati~n to ~he theoretical capac1~ :
~alue;
FIGURE 2 ig a graph showing the e~fect o~ NiO
CoO ~ Na~02 reaction time on the per~ormance o~ nickel elec- ;
trode plateæ, FIGURE 3 i~ a graph showing the effect o~ NiO
CoO ~ Na202 reaction temperature on the per~ormance of nickel electrode plates; -~
FIGURE 4 is a graph showing the ef~ect o~ the weight ratio NiO:Na202 on the per~orm~nce o~ nickel electrode ;~
plates;
FIGURE 5 is a graph ~howing the e~ect oP the co-balt concentratlon on the per~ormance o~ nickel electrode pl~tes; and, FIGURE 6 ~hows a pre~erred electrode plaque loaded with the active battery material o~ tht~ lnvention~
DESCRIPTION OF 1~ PREFERRED 3MBOD~E~TS
One embodiment o~ a battery~ utilizing the improved active m~terial and electrode p~ate o~ the inventlon~ would -5- _ ~0533~
generally comprise a pluralit~ o~ alternate poRitive nickel plates and negative plates 3uch as, for exampleg loaded iron active material plates. mls stack up would contain plate separators between the positive and negative plates, all contacted by alkallne electrolyte and housed ln a case having a coverJ a vent, and positive and negative te~minals.
Pre~erred electrode plaques, shown in Figure 6,.
are made ~rom m~tal ~ibers, pre~erably nic~el, or metal prs~
tective coated ~iberæ~ 3uch as nickel coated steel or iron~
A very suitable material $s nickel cvated steel wool. m~
plaque 10~ is ~ flexible, expan~ible, compacted sheet o~
relatively ~mo~th, generally contactl~gJ intermingled~ metal ~ib~,rs as shown at 11 in the body o.f the plaque. The plaque :-ha~9 in the embcdiment shown~ top edge 12 coined to a high density. The coined area provides a base to ~hich lead tab I~, which ls attached to battery terminal~, is spot welded~
me plaque is generally betueen about 90 and 95~ porous~ . -Thl~ range i~ preferable ln provlding improved conductivity`~
and electrol~rte permeability) whlle maintaining enough body 20 ~or good plaque loading. Activated nickel electrode material ~s lo~ded lnto the interstices o~ the body o~ this ~ibrous plaque to pro~ide an electrode plate. m~ inventlon~
however, is not restricted to the pre~erred plaque structure described herein, and the active material can be u~ed ~ith other metallic plaque ~tructures, .
The metal ~ibers are pre~erably di~u3ion bonded in a protective atmo~phere at temperatures up to the sinter-lng point o~ the fibers used, In di~usion bonding, the ~ibers ~ust n~t be melted, or protuberances will be rormed ~educing active material loading (volume) within ths plaque.

i~)533Z5 .

mere should only be a metallur~ical bond and interdi:Ef`u~ion o~ atoms across the fiber interface at fiber contact points 14 along the ~iber lengths, Dif~u~lon bonding provides a ~lexible~ expansible electrode structure having a large pore : volume into wh~ch active material can be ~asted or otherwi~e ; impregnated. Dif~usion bondlng also lowers the elec trode :~
plate re~istance appreciably and thus the lnternal cell re-sistance in a ~inished cellO
: me actlve material is prepared by mixing the nickel oxide with ~odium peroxlde and ~hen heating the nickel oxlde (N~O) and sodium peroxide (Na202~. mese materials are generally in powdered or particulate *orm~
The starting material preferably contains between about 2-12 wk% cobalt, based on Ni plus Co, added as element~l cobalt ~:
or pre~erably as a cobalt oxide such a~ Co2~3~ Co304~ CoO ~.
or their mixtures. These reactants are preferred to be o~ :~
moderate to high purity. They are fused and melted, generally in a suitable high temperature resistant container, *or example a nickel cruclble~ in an oxldi~in~ or in~rt atmos-phere, ~n an oven maintained at a temperature Or between about 800 -1150 C~ ror ~bout 1/2 - 8 hours, It i~ e~sential in terms o~ a commercial process to use the oxid$zed nickel (NiO) as starting materi.alJ ~ince otherwi~e long oxidation o~ Ni to N10 w~ erlously degrade and ruin the expens~ve reaction container.
In the reaction, the sodium peroxide deco~po~es to ~orm Na20 which oxidizes the N~O. We have ~ound~ unexpect- ;
edly~ that a high capacity9 easily pasteable active battery material is ~ormed when the re~ction product is then hydro-ly~edg generally by immer~ion in waterJ to cause a deco~po-,......... .

11~533~S
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sition r~action and forma-tion of Ni hydrated oxid~ and Ni hydroxide forms and cobalt hydroxide. The active material is generally washed until neutral to litmus and then may be dried at a temperature that will not degrade activity, e.g., between about 15C - 65C. The NaOH formed could be drawn off in some continuous fashion and concentrated by evapora-tion, for example, into a saleable product.
A set of equations which in part describes the basic preferred fusion and hydrolysis r~ac-tions can be given as:
NiO + CoO + Na22 (Fusion) ~ NaNiO2 ~ NaC002 2NaNiO2 -~ NaCoO2 + 3H20--~3Ni(OH)2 + CoOOH + NiO2.(1-2)H20 + 3NaOH
We found in accordance with the prior art that cobalt addition was necessary at some step in the method to `
provide an active material in the electrode plate which would have superior electrochemical performance, i.e., a capacity of about 0.185 amp-hours/gram active material, after 25 cycles.
The cobalt, in the form of elemental Co or cobalt oxide is added preferably befor~ the Pusion step, but cobalt additive may be added instead to the paste after the hydrol-ysis step, genera].ly as cobalt hydroxi.de Co(OH)2, prior to incorporation into the plaque. ~When cobalt additive is added as elemental cobalt or as a cobalt oxide, before fusion, the active material contains cobalt (III) hydroxide;
if added in a Co hydroxide form after hydrolysis, the active material contains cobalt (III) hydroxide. Cobalt hydroxide is expensive and when added after hydrolysis does not provide , completely homogeneous mixing.
Generally the nickel hydrated oxides and hydroxide ,, . . ~ - . . , . , . . : . ~, . . .. . . ;, . . .. ... . . .... . . . .

` ~L053325 ~orms will be washed to remove mo~t of the ~aOH and the cobalt hydroxide may be added a~ an aque~us slurry; or the nickel material may be d~ied and the cobalt hydroxide mixed with it ln a sultable mill or other type mixer. Also, during or a~ter hydrolysi~, aqueous cobalt chloride (Co(Cl)2. ~H O) or cobalt nitrate (Co(N03)2. 6H~o~ addl-tive may be u~ed, in which case a~ter reaction with alkaline hydroxide pre~ent or added~ the final ac~ive material will contain co~alt (II) hydroxide, Co~H~, Addition of an approprlate amount Or cobalt nltrate solution to the al~aline .~.
.~ slurr~ a~ter h~droly~i~ result~ in a falrl~ uni~orm dispersion o~ Co(OH)2 preoipitate with the nicl~el active material.
me plaque can also be loaded with battery material not containin~ cobalt, and then dipped ~or ~n adequate period o~ time in aqueous cobalt nitrate or chloride ~olution, dried, a~d ~inally dipped in alkali hydroxide~ ~uch as EOHJ
Na~H or LiOH9 to provide a precipitate o~ Co(OH) in the material. This would al~o provide a useful method to upgrade the cobalt content o~ loaded ~laques.
In all cases, co~alt additio~ is pre~erred and the j~ total weight percent o~ cobalt9 as Co ln tha active material~
mu~t be betwee~ about 2-12 wt% and pre~erably ~bout 5-8 wt%
o~ the ~nitial weight of NiO plus Co3 i.e~ wt~ Co = Co/tNiO ~ Co) Cobalt concentration below ~ wt% and above 12 wt% detracted from accepta~le per~ormance, Fall~re to add cobalt to the plaque proYlded a plate having a capacity of about O,tO amp-hr,/g, A u~e~ul active materlal can be made wlthout con~aininæ
cobalt9 but a plate containing such material, be~o.re bein~
used ln a bette~, should be dipped in a cobalt solution to insure cobalt content and obtaining higher capac~ty.
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~332S ; ~

We found that the weight ratio of NiO to Na202 was critical in providing an electrode pla-te having acceptable electrochemical performance. The weight ra-tio of NiO:Na202 must be between about 1:1.35 to about 1:2.1. An amount of -Na202 less than about 1.35 parts per 1 part NiO would provide relatively poor performance. A 1:1 weight ratio of NiO:Na202 provided a mixture that remained in slurry form with incomplete reaction. An amount of Na202 over about 2.1 parts per 1 part NiO causes rapid destruction of the reaction vessel and does not provide increased electrochemical capacity. Other peroxides similar to sodium peroxide, such as lithium pero~ide ;-or lithium oxide and potassium superoxide as well as barium, strontium, and calcium alkaline earth peroxides were found unsuitable.
We found that -the temperature and time of reaction ~ i :.
melt fusion of the NiO and Na202 influenced the capacity of the active product. Temperatures around 700-750 C provided ; `
a reaction mixture that was still somewhat semi-solid, indi-cating slow and incomplete formation of NaNiO2 and incomplete intimate reaction of the NiO and Na202. At a temperature of 600C most of the NiO does not react. Tempera-tures held, after heating th~ oven, at over 1150C provide materials problems in finding suitable reaction vessels which will not d~grade very quickly and add deleterious materials to the fused NaNiO2.
The useful temperature range for complete fusion-reaction, to be maintained after heating the oven, is between about 800-1150C. The preferred fusion-reaction temperature range, to be maintained after heating the oven, is from about 850-1100C. The most preferred temperature range in - 1 0 _ ''.`' .'' ~. ,, ~5;~3~5 order to assure reuse of the preferred nickel reaction vessel is between about a50C-925C. The time necessary for fusion will vary depending on temperature. At 800C - 850C, ; 6-8 hours is generally sufficient for complete reac-tion, - ,~
while at 850-1100C or higher, 1/2-3 hours is gen~rally adequate. The best performance was observed at a fusion-reaction temperature of 1000C for 2 hours.
The water temperature for the hydrolysis reaction of the NaNiO2 can be between about 10C-95 C but preferably 10 between about 20C-35C. When reacted between 20C-35C the reaction provides more Ni (III) hydroxide i.e., a weight ratio of Ni ~ hydroxide:Ni (III) hydroxide of over about 1:2 providing better electrochemical properties. A higher concentration of the more crystalline Ni (III) hydroxide also provides a composition that loads better into the plaque.
The molten NaNiO2 can be quenched in water at NaNiO2 temper-atures below about 600 C, ~.e., the NaNiO2 can be cooled to below 600C and then immersed in water; this however pro-duces a very active hydrolysis, and it is preferred to cool 20 the NaNiO2 to between 20C-95C before hydrolysis~ Also of particular advantage in this method, NaOH solution is pro-duced which may be further used as a battery electrolyte.
Th'e final active material will contain nickel hydrated oxides and hydroxide forms plus cobalt hydroxide.
It will also contain about 0.5 to 5 wt~ but generally about

2 wt% unhydrolyzed or unreacted NaNiO2, based on dried nickel hydrated oxides and hydroxides plus cobalt hydroxide forms. This sodium material imparts importantreduced swelling properties. The ac-tive material is then washed and dried. This material can be made into a high density fluid : . ~

~0S33'Z:5 "
active battery paste for application to battery plaques.
The active mat~rial a~ter drying up to 65c contains water molecules betw~en spaced -O-Ni-O- layers. It is essential that the water remain in the structure. Therefore, drying is of a partial nature and must be accomplished at a temper-ature and humidity efective to retain an optimum amount of the interlaminar H20. Generally the temperature limits are between about 15 C to 65 C with a preferred range of 20 C- ;;
40 C. Above 65C drying and the electrochemical activity i~ 10 starts to decrease. Above 100C drying, the electrochemical ~ .
activity continues to decrease to the extent that the material starts to become inactive. Above 130C involves complete drying and the cubic NiO electrochemically inactive sta-te is formed.
For simplicity, one of -the nickel hydroxide forms comprising the final hydrated active material has been written as nickel (III) hydroxide. This is a simplified way of stating an average between Ni (II) and Ni (lV) hydroxides.
There is considerable speculation as to the precise formula 20 of the higher valen-t, oxidized nickel hydroxi.de. Analysis ~ :' of several samples of hydrolyzed NaNiO2 were obtained using the dimethylglyoxime gravimetric technique. ~The results indicate that a primary nickel compound corresponds to a stoichiometry of Ni30~.2H20, a nickel oxide hydrate. For the purposes of this application, the term nickel (III) hydroxide and nickel hydrated oxides and hydroxide forms will be used to identify the electrochemically active nickel compound obtained by the substantially complete chemical hydrolysis reaction of NaNiO2.
The sodium peroxide, nickel oxide, cobalt and co-':' . . . ~ ........ : ... .. .
:, , . . : .

~)S3325 balt oxide starting materials, as well as cobalt hydroxide and wat~r solubl~ cobalt salt additives are preferred -to be substantially pure, i.e., no mor~ than about 5% of electro-chemically harmful impurities -that cannot be washed away.
Fortunatel~, commercial grades of black nickel oxide powder are sufficiently pure to be used as supplied.

An electrode powder active battery material con-taining about 98 wt% cobalt - nickel hydroxide was mixed by placing in a container and thoroughly blending 7.~ grams (0.10 mole) of 99+% pure, finely divided black nickel oxide, NiO, (containing 7a wt% or 5.9 grams Ni) and 0.38 grams `
(0.005 mole) of 99% pure cobalt oxide, mostly in the form o~
CoO, (containing 70 wt% or about 0.27 gram Co) with 11.7 grams (0.15 mole) of C. P. (96.5% chemically pure) grade sodium peroxid2, Na202. The nic~el oxide consisted essen-tially of NiO and was commercially available as INCO black NiO; tho cobalt oxide comprised mos-tly CoO and was commer-cially availabIe as BAKER reagent cobalt oxide, containing 70 wt% Co. This provided approxima-tely a 3.4 wt% cobalt concentra-tion based on nickel oxide plus cobal-t content, i.~., 0.2~ g Co divided by (7.6~g NiO + 0.27 g Co); and a weight ratio of NiO:Na202 of about 1:1.54.
This mixture was then placed in a nickel crucible and gradually heated for about 1 hour up -to about 800C in air, in a ceramic lined oven with Nichrome heatin~ coils.
Temperatures were monitored using a Pt-PtRh thermocouple introduced at the rear of the oven. After the oven was heated up to aooc, the temperature was increased and maintained at -~he fusion-reaction temperature of between about 950C-~, ~` ~05332S
:~
s 1025C for an additional 1 hour, to ensure substantially complete chemical melt-fusion reaction to a substantially pure NaNiO2 NaCoO2 mixture.
The crucible and reaction product contents were -then cooled to about 25C over a 6 hour period, after which the crucible containing a solid mass of material was imm~rsed in a 250 ml beaker of water at about 25C. ~The con-tents hydrolyzed over a 12-hour period, and dispersed in the water to provide an active batterymaterial powder containing 10 about 98 wt% reacted oxide hydrates and hydroxides with about 2 wt% sodium on a dried basis as unreacted NaNiO2.
The heavy brown-black solid active material settled immedi-ately in the beaker and was separated using a conventional .
Buchner apparatus. It was washed with successive 100 ml portions of water until neutral to litmus. This provided a dense brown-black crystallino powder material. It was noted that the nickel crucible was somewhat degraded after the reaction. ~The filtrate consisted of NaOH solution, which , .
could be used later as a battery electrolyte.
This active battery powder was then air dried at only 25C, so as not to eliminate interlaminar wat~r in the crystals, and sieved to -325 mesh, i.e.,~about 98% of the ~I d powder had a diameter of less than about 44 microns. This powder was thon loaded into nickel battery plaques or grids.
The grids were 90-95% porous, 100 mil thick diffusion bonded nickel plated steel wool fiber plaques, having an area of about 1 sq. in. They were loaded using a conventional suction platform. An aqueous slurry of the active material was made to provide a high density fluid paste which was 3b added from a blender un-til the plaques were filled. Addi- ~
-- 14 -- : -. ~L0533~5 . ~
`
, tional water was dropped onto the loaded electrode plates i. from a funnel to obtain op-timum packing within the plaque support.
Sample lta) electrodes, having an initial thickness -~
of about 100 mils, were then pressed at about 20,000 lb/sq. in., to a final thickness approximating 60 mils. The loading in each plaque was about 1.5 grams/sq.in. of plaque surface area.
Sample l(b) electrodes, having an initial thickness of about 100 mils, but more heavily loaded, were then pressed at about 20,000 lb/sq.in., to a final thickness approximately ao mils.
The loading in each plaque was about 2.5 grams/sq.in.
The nickel electrodes of Samples l(a) and l(b) were set opposite negative electrodes in several containers, and contacted with electrolyte to form electrochemical cells. The nickel hydroxide electrodes were "formed", i.e.l, charge and discharge cycled versus sintered cadmium electrodes of con-siderably larger size and capacity. They were charged for about 2-1/4 hours at a current density of about 0.3 amp~sq.in.
in 25 wt% aqueous KOH and discharged through a 10 ohm resistor at a current densi-ty of approximately 120 mA/sq.cm. in 25 wt%
aqueous KOH electrolyte. ~The amoun-t of charg~ for each cell was adjusted to about 250% of -the theoretical nickel capacity based on a single electron trans:eer per n:Lckel atom.
The cycling increases the porosity of th~ electrode, allowing increased electrolyte penetration and higher output.
Initially7 the active material is tightly packed and the electroly-te is restricted from contacting the interior of the electrode. An electrode is ready for use after "forming"
for about 10 to 35 cycles. The active materlal after "forma-tion" did not show any appreciable swelling in the battery , :

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elec-trode plate.
Capacity values which we considered acceptable for nickel hydroxide battery material were over about 0.185 amp-hr/gram active material after 25 cycles. ~This would provide an active battery material highly effective in approaching theoretical values and much improved over the prior art.
Theoretical values for one-~lectron trans~er, at 0.255 amp hr/g, are shown on Figure 1 as a broken horizontal line.
The capacity of the electrodes made by the method described above are also shown on Figure 1, as curves l(a) and l(b), providing a capacity at 25 cycles of between about 0.225-0.20 amp-hr/g. The electrochemical performance of Sample `~
l(b) is about the same as for Sample l(a) even though the ;~
electrode is much thicker and more heavily loaded. This is of particular advantage, indicating that low loadings, providing eyen lower materials costs, will still provide excellent electrochemical results.
An electrode powder active battery material, Sample l(c), containing about 98 wt% reacted oxide hydrates 20 and hydroxide forms was made by adding about 10 grams reagent grade, 99% pure, cobalt nitrate solution, Co(N03)2. 6H20, (containing 20 wt% or 0.35 gram cobalt) -to the strongly alkaline hydrolyzed slurry after the crucible was immersed in water, rather than adding cobal-t addi-tive to the NiO -~
Na202 mixture before fusion. This provided an active battery mat~rial containing cobalt (II) hydroxide dispersed through-out. The mixture before fusion contained 7.6 grams NiO and 11.7~grams COP. grade sodium peroxïd~, providing a weight ratio of NiO:Na202 of about 1:1.54. The same fusion, cooling, 30 hydrolysis and washing cycle was followed as described for f '~ .

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~Q~332S

Samples l(a) and l(b) above. The cobal-t concentration based on nickel oxide plu9 Co content was 4.4 wt%, i.e., 7.6 g.
Ni:0.35 g. Co. This active battery material was loaded, pressed, set opposite negative electrodes to form a cell, and charged and discharg~d as described above for Sample l(a).
The capacity of this electrode is also shown in ~igure l, as curve l(c), providing a capacity at 25 cycles of about 0.19 amps-hr/g. Mixing the cobalt additive initial-` lO ly as CoO, as in Samples l(a) and l(b), appears to provide an electrode active material with more capacity, probably be-cause of the intimate interaction wi-th NiO and Na202 during the melt-fusion reaction, and is the preferred method o-f adding cobalt to the battery material.
The cobalt could also be added by dipping or spray-ing a plaque containing the nickel hydroxide after loading, followed by dipping or spraying with high purity alkali hydro-xide to precipitate cobalt hydroxide and then washing the plaque. When the cobalt weight percent is between 2-12 wt% ~ t the results would be similar to Sample l(c). Cobalt can also be added as high purity CotOH)2 after hydrolysis and when the cobalt weight percent is between 2-12 wt% the results would again be similar to Sample l(c~. None of -the post fusion cobalt addition methods, either as a cobalt hydroxide or as soluble cobalt nitrate or cobal-t chloride salts, provide as complete a homogeneous mixing of the cobalt with the nickel hydroxides.
Nickel analysis of several ba-tches of the hydrolyzed NaNiO2 of Samples l(a) and l(b) were obtained, using the r~ ,, dimethyglyoxime gravimetric technique. The results indicate 33Z~

50-60 wt% nickel due to varying degrees of hydration, plus cobalt, oxygen and residual sodium, as shown in TABLE 1 below:

-:
l r ~ . . :~ /
Nickel analysis for ~ully hydrolyzed NaNiO2 samples ,, . ~._ .__. ~: ~
Sample Wt. (~.) Ni Content (~.) % Ni 0.155 o.oago 57.6 0.147 0.0902 61.4 ~ -0.151 0.08~2 55.7 . 14a o. oa40 s6.8 , - . . . _ ~ . . . ~
The leaching of sodium from NaNiO2 was very slow. Even after a week of washing a sample of :Einely ground NaNiO2 with water, the sodium content was still about 1.0 percen-t.
The hydrolyzed NaNiO2 star-ts to lose significant weight above 130C. Some interlaminar water is believed to be lost at heating temperatures over about 45C-~5C. In the range of 130C-240C, the compound loses oxygen and residual water amounting to about 13.0 wt,%. Heating above abou-t 130C involves complete drying and eliminates almost all interlaminar water, causing Ni in the crystal structure to link with 4-6 oxygen atoms forming a cubic electrochemically inactive state. The values resulting from the dimethyglyoxime analysis of the active material closely correspond to a stoichiometry of nickelo-nickelic hydrate, Ni304~- 2H20, in a layer like -O-Ni-O-Ni-O-Ni-O- form with interlaminar water, which on conversion to NiO, would lose about 18.9% of its weight. The nickel content of Ni304 2H20 is calculated to be about 63.~%. The values given in TABLE 1, when corrected ~ 533Z5 for the 5-6% cobalt additive, agree with this percentage reasonably well.

An electrode powder active battery material was mixed by placing in a container and thoroughly blending 7.$
grams of 99+% pure NiO (containing S.9 grams Ni) and 0.56 grams of 99% pure cobalt oxide (containing about 0.44 grams Co) with 11.7 grams of C.P. grade sodium peroxide, Na202.
This provided approximately a 5.5 wt% cobalt concentration based on nickel oxide plus cobalt content, i.e., 7.6 g. NiO
0.4~ g. Co and a weight ratio of NiO:Na202 of about 1:1.54.
This mixture, i.e., NiO:1.5 Na202 wi-th 5.5 wt% co, was then placed in nickel crucibles and 4 batches, Samples 2(a)-2(d), gradually heated about 1 hour up to aooc in air, in a ceramic lined oven with Nichrome heating coils.
Temperatures were monitored using a P-t-PtRh thermocouple introduced at the ~ear of the oven. The temperature was then increased and maintained at the chemical fusion-reaction temperature of 1000C for further periods of 20 minutes, Sample 20 2(a); 1 hour, Sample 2(b); 1.5 hours, Sample 2(c~; and 3 hours, Sample 2(d); to determine the effect of fusion-reaction time on the electrochemical performance of the actlve battery ma-terial.
The crucible was -then cooled to 25C and immersed in water at 25C to hydrolyze and disperse the contents.
The hydrolyzed material containing about sa wt% reacted hydrated oxide and hydroxide forms and 2 wt% unreacted ~;
NaNiO2 on a dried basis, was then washed until neutral to .
litmus, dried at 25C, loaded into nickel battery grids, and set opposite nega-tive electrodes to form c~lls; all steps - 19 - ,~

:' ' ~,:
`': ... ' ' . ,~ . .~ .

~ ~1)53325 -::
.
using the same techniques as described in Sample l(a) in EXAMPLE 1.
Th~ electrochemical activity of these electrodes are shown on Figure 2. The material heated at 1, 1.5 and 3 hours at the fusion-reaction temperature of 1000C provided capacity values at 25 cycles of about 0.21, 0.22 and 0.23 :
~ ., .
amp-hr/g. The material hea-ted for 20 minutes at the fusion-reactor -temperature provided capacity values at 25 cycles of 0.17 amp-hr/g. Suitable reaction times at fusion-reaction 10temperatures of between 800-1150C would appear from this data to he over about 1/2 hour and probably up to about a hours at the aooc temperature range.

;~An electrode powder active battery material was made as in EXAMPLE 2, i.e., NiO:1.54 Na202 wlth 5.5 wt% Co. Sam-ples of this mixture were then placed in a nickel crucible and heated for 6 hours at 600C, Sample 3(a); 6 hours at 700C, ISample 3(b); 6 hours at ~00C; Sample 3~c); 6 hours at 850C, Sample 3(d); and 2 hours at 1100C, Sample 3(e), after ini-tial furnace heating, to determine the effect of temperature on the electrochemical performance of the active bat-tery material. The furnace was th~ same type used in EXAMPLE 2.
The arucible was then cooled to 25C and immersed in water a-t 25C to hydrolyze and disperse the contents.
The hydrolyzed material, containing about ga wt% reacted hydrated oxide and hydroxide forms and 2 wt% unreacted NaNiO2 on a dried basis, was then washed, dried at 25 C, loaded into nickel battery grids, and set opposite negative ~ -electrodes to form cells, all steps using the same techniques as described in Sample l(a) in EXAMPLE 1 .

;33Z5 - The electrochemical activity of these electrodes are shown on Figure 3, where the materials heated at 800, 850 and 1100C provided capacity values at 25 cycles of about 0.19, 0.20 and 0.23 amp-hr/g respec-tively. The mater ials heated at 600 and 700C provid~d capacity values at 10 cycles of only about 0.05 a~d 0.15 amp-hr/g. Suitable fusion-reaction temperatures would appear from the data to be between about 800C to 1100C or higher, although at temperatures above about 925C the nickel reaction vessel shows signs of deterioration.

El~ctrode powder active bat-tery material was mixed by placing in a container and thoroughly blending 7.6 grams of 99 % pure NiO (con-taining 5.9 grams Ni) and 0.5~ grams of 99% pure cobalt oxide (containing 0.4 grams Co), to provide a 5.5 wt% cobalt concentration, with about 7.6 grams oP COP.
grade Na202, Sample 4(a); about 9.5 grams oP C.P. grade Na202, Sample 4(b); about 11.7~grams of C.P. grade Na202, Sample 4(c); and about 15.2 grams oP C.P. grade Na202, Sample 4(d). This provided weight ratios oP NiO:Naz02 of about 1:1; 1:1.25; 1:1.5; and 1:2.0 respectively. The mixtures were then placed in a nickel crucible, he.ated, and then Puse-melted at a Pusion-reaction -temperature of 1000C
for 3 hours.
These materials were then cooled to 25C, and immersed in water at 25C to hydrolyze them to Co hydroxide `;~
': :.:.:
plus Ni hydrated oxide and hydroxide forms and about 2 wt% ~`
unreacted NaNiO2 on a dried basis. The material was then washed, dried at 25C, loaded into nickel battery plaques at a loading of about 1.5 grams/sq.in., and se-t opposite negative - 21 - ~ .

. ' .

` ~o~i33~25 ::
electrodes to form a cell, all steps using the same techniques as described for Sample l(a) in EXAMPLE 1.
The electrochemical activity of these electrodes are shown on ~igure 4, where the materials having weight ratios of NiO:Na202 of 1:1.5 provided capacity values at 25 cycles of about 0.23 and 0.22 amp-hr/g. The materials having weight ratios of NiO:Na202 of 1:1 and 1:1.25 provided capacity values at 25 cycles of about 0. oa and 0.15 amp-hr/g. Suitable we~ght ratios of NiO:Na202 would appear from 10 the Figure data to be between about 1:1.35 to about 1:2.1.

EXA~IPLE 5 Electrode powder active battery material was mixed by placing in a container and thoroughly blending 7.6 grams of 99 % pure NiO (containing 78 wt% or 5.9 grams Ni) and 11.7 grams of C.P. grade Na202, to provide a weight ratio of ,~ NiO:Na202 of 1:1.54, with about 0.23 grams of 99% pure cobalt oxide (containing 70 wt% or 0.16 gram Co), Sample 5(a); about 0.38 grams of 99% pure cobalt oxid~ (containing 0.3 gram Co), Sample 5(b); about 0.7 grams of 99% pure 20 cobalt oxide (containing 0.49 gram Co), Sample 5(c); about 0.9 grams of 99% pure cobalt oxide (containing 0.63 gram Co), Sample 5(d); and 5ample 5(e) con-taining no cobalt addition either before fusion or after hydrolysis. I'his provided cobalt concentrations, based on nickel oxide plus cobalt content as Co of approximately about 2.1 wt%, 3.
wt%, ~.1 wt%, 7.5 wt%, and O wt% respectively. The mixtures were then placed in a nickel crucible, heated, and then fuse-melted at a fusion-reaction temperature of 1000C for 3 hoùrs.
These materials were then cooled to 25C, and im-. ~ . . . .................................... :
., ~, . .......................... .
. . ,: . . . .

3 ~ S

mersed ln ~ater at 25C to hydrolyze them to about 98 wt~
reacted h~drated oxide and hydroxide Porm~ and 2 wt% unreacted NaNiO2 on a dried basis. The materials were then washed, drled at ~5 C, and loaded into nickel battery plaques~ at loadings o~ 1,7 grams/sq,in. for a ~inal pla~ue thickness o~
70 mils, and set opposite negati~e electrodes to ~orm a cell, all steps using the same techniques, as described ~or Sample l(a~ in EX~MPLE 1~
The electrochemical activity of these electrodes are shown on Flgure 5, where the materials having cobalt concentrations o~ 2.1 Wt%J ~,8 wt%~ 6rl wt%~ and 7.~ wt~
pro~ided the capaclt~ values at 25 cycles of about 0.22, 0.22, 0.24 and 0.20 amp-hr/g. respecti~ely, The material without cobalt provided a capacity value o~ only 0.10 amp-hr/g. a~ter 25 cycle~. Suitable cobalt addition ~rom ~his data to provide an acceptable electrode plate ready ~or insertion into a battery would appear ~o be between about 2 wt~-12 wt~ based on nickel oxide as NiQ plu~ cobalt content as Co, EXAMPIE 6 ;
As a comparative exampleJ a materialJ Sample 6J
containing between about 95-98 wt~ hydrolyxis reaction pro-duct was m~xed b~ placing ln a con~ainer and thoroughly blendin~ 30 grams o~ 99 ~ pure NiO, (containln~ 24 grams Ni)J and 2. grams of 99% pure cobalt oxide (co~taining 1,5 gr~ms Co) with 50 grams of CO P. grade potassium superoxide, K02. mis provlded a 4,8 wt% cobal.t concentration based o nickel oxide plus cobalt content and a weight ratio of NiO::E02 o~ about 1:1.65. ~his mixture was then placed in a nickel ~rucible and heated over about 1 hour to 800 C" me ~ .
-23-- :

~)533~ :
~emperature was raised ~nd maintained between 950-1025 C
~or about 2 hours to en~ure complete melt ~u~ion rea,ction to XN~02 ~ KCoO2.
Thi8 material was then cooled to 25C, and immersed in water at 25C to hydrolyze it. me materlal was then washed, dried at 25%~ loaded into nicke3. battery pla~ues ~t a loading o~ about 1.~ gram~/sqOin~ and set oppo~ite nega-tive electrodes to ~orm a cell, all steps using the ~ame ~echnique~ a$ des~ribed ~or Sample l(a) in EXAMPLE lo The capaclty o~ these electrode~3 Sample 6~ ~ade substitutlng K02 ~or Na202, pro~ided a capaci~y o~ 0,12 amp-hr/g. a~ter about 25 c~cles~ indicating much in~erior electrochem~cal performance ~or this material.

a comparative example, an electro~e wa~ made, ~imllarly to Sample l(a) in EXAMPLE 1, ~Jhere LizO w~s sub-stituted for Na202 in the mixture~ The material contained about ~.4 wt~ cobalt concentra~ion and a ~eight ratio o~
NiO:L120 Or about 1:1,5. m is mixture was ~u~ed at 1000C
to ensure substantial reaction to CoS.Li20, although the mlxture remained solid d~e ~o the high melting point o~
L120, cooled to 25C~ and hydrolyzed in water at 25C. me material was then washed, dried at 25 C, loaded lnto nickel battery grids, and ~et oppo~ite negativ~ electrodes to ~orm a cell, all steps uslng the same technlques as described for Sa~ple l(a) in EXAMPLE 1. me ~lnal product was a gray-black powder with some dispersed metallic-like platelet~.
me electrode~, Sam~le 7(a), made by substituting Li20 ~or Na 0 , had only super*icial electrochemical activit~ X~ray and in~rared reasurements indicated that the LiNiO2 contained - . . . :

~ 45,3Z~ ~

t ~LO~;3~
a cubic NiO structure and not the layer-like NiO2 structure found in NaNiO2 necessary for electrochemical ackivityO
Also, electrode Sample 7(b) was made using the same techniques as described for Sample l(a) in EXAMPLE 1, but substituting barium peroxide, BaO2~ f~r Na202. The final product, BaNi205 ~ BaCo205 had no electrochemical activity. X-ray structural patterns also showed NiO sitesO ~ :
In addition, the hydrolysis step produced Ba(OH)2 which was :
insoluble, inactive dead weight and difficult to separate ~:
from the barium cobalt and nickel oxides by washing.
Tabulated results of the Examples are shown in the following TABLE 2~

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:~ 45, 328 ~. . ' ~ ~5~3Z5 ,~f _ . .~ _ ~
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C~ N O a~~ ~1 ~1 Cr) ~ L~ o~ O ~ oO ~ ~ c~l ~ ;:~ N N rl ~I N N N O ~I r-l N N O r1 N N
! ~ W O ... .... S:~ ..... ....
S~ LO O O o O O O Q ~ o O O O O O O O
r~ ~ ~J .
o a~ ~ .~ ~
~ ~ Q) L~ L~ ., L~ W O ~1 0 C~) C--~I N t~l Lr~ L~ ~) a:~ ~D ~ N
N O N N ~1 ~I N N N O ,1 ~1 ,I N O ~1 N N
0~ O 000 OOr-i0 00000 0000 i ~ _ ,,, . . ___ , .~ .
O ~ ':,, ~' ~ ~0 ~ ";
~ L~L~\L~ L~LL~LL~L~ L~L~L~L~L~ L~L~Lf~L~ .' r-i N ~i ~i ~i r--i ~i r-i ~J ~i r-i vi ~i ~1 ~i ~1 : ~.
~: ~bO ''"
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t~.l g S ~ O O O ~J ~I ri t'f) ~ ~ ~
~ or~W ~1~ VVVV . C~ VVV~
N C~ O o o 0 0 0 C3 V V V ~ o o o o o ¢~ C300 OOOC~ 00000 0000 c~ L~ Lr~ L~ O O C3 o O O O L~ ,1 O O C~ O
~ o o~ r~ l ~D~cx)a~,l r~ l E-l o . .. ~ _. _. _ . ~ ~ .

W ~W
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~ (d ~ ~ ~ R~ ~ * ~ 1* ~ ~ ~S ~ ~ ~ t~ ~ .
V ~ J~ ::1' 3 L~ L~ L~ Lt~ Lr~ L~ Lt~ Lr~ LO L~\ Lr L~ Lf~
O orl ~ ~ ~) 3 Ln L~ L~\ L~ L~\ Lr\ L~\ L~ Lf ~ Lr~ L~\ L~ L~
Q. N . . ..
E~l 1~ ~: h . .: .
V ~ -rl H
C~ _._. ___ ..... __ ____ .':
V . .

ci O N
H N Lr~ Ll~ L~ L i L~ L~ Lf~ 3 S =~ S 3 O N L~ o 1~ 1:~:; Z ... .... .... . ... o .
E~ ~ 1 ~ 1 ~ 1 :

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C) N N :::1' 0 0 N ~) O
~, ~ ~ C~ N ~ N ~1 ~1 ~1 O O

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,. ~ tl~ ~ V) ~ _ ~ `' ' : ' '` 13~ V ~ ~1 ., . ~ ~ C> ~ ~ O o ~ ~ :, :
h N N C'J ~'J ~1 l O O
:'i, o~ O O o O O O S:~ ~ "' :'' ' '' l ~1 ~3 . . . .~ __.__ N rl .....
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1~ LS~Ll~ Ln .. .
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~ E~ .~::S~ v V V ,''. :' , N O ~ ~ N N N
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~ ~ ~ O O C~ O O ol ol ol '': '', O ¢~ 00000 O O O
V ¢ OOOOO L~ L~
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V ~rl 0 ~ . o ~ ~ ~ l ~ ~ .~
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V ., __ ~ __ . . ., _ H O N ~ ~t J 3 -~ oN~ O O
1~ 0 0 15~ LO Lr~ Lr~ Ls`\ ~ ~D ~ LO
E~ O ~ i O -i i-i O r-i ''~
~2 ~ 1 Z ~iZ ri Zri ,.,~ ,., `,~' " ' ~; ___ _, ,~' ':~ .. '~.':
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5i33Z5 , ...................................................................... . .

In order to determine the effect of drying temper-ature on the electrochemical capacity of the active material, an electrode was made, similarly to Sample 2(d) in EXAMPLE 2 but using drying temperatures after hydrolysis of 25C, j 30C, 40C, 45C, 70C and 905. The material contained ~' about 6.5 wt% cobalt concentration and a weighk ratio of NiOoNa2O2 of about 1:1O54. The mixture was fused in a ' nickel crucible at 1000C as in EXAMPLE 2 to ensure complete ;
;~ 10 conversion to NaNiO2. After cooling and hydrolysis, the active battery material powder contained about 98 wt% reacted hydrated oxide and hydroxide forms and 2 wt% unreacted NaNiO2 on a drled basis.
The material was washed and then Samples 8(a)-8(f) ! wer-e air dried at the above described temperatures. The Samples were then sieved to -325 mesh and Ioaded into nickel battery plaques as in EXAMPLE 2. The electrodes were pressed and had approximately the same loadings as in EXAMPLE 20 These nickel electrodes were set opposite negative electrodes . . .
in several containers, and contacted with electrolyte to form electrochemical cells. The electrodes were fromed as ln EXAMPLE 2. The capacity of the electrodes after level per-formance was attained at about 25 cycles is shown in the following TABLE 3: ;~

' .
~ .

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~5,328 ~ :`
: .

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:; , ' , . , . _ __ . . _ :,'.' .

~ 0 Ln ~ LnCO Ln o ,. ~ ~rl ~ C) ~ ~ ~ a~ ~ ~
~ Ln c) ~ p~ ~u N(~l ~1 ~1 o t'J ~ V O O O O O O ,:
Os: ~ ~Ln ~ ~ ~
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~0 ~ Ln Ln Ln Ln Ln Ln S ~\ ~ . ~
o p~ ~
~ ~--~ ~ ~ S S ~5~ S S
a)~rl ~ ~ ~ ~ ~ ~
E~ E~ ~ , S~ ~d c~ , , o o ~ o o o o o o ~d o o o o o o co o o o o o o ::~ o o o o o o ¢ ~ ¢~ ~ ~ ~1 ~1 ~I rl E~ o ' " .", . ~_- _. ~
O N j .
-1 0 ~ ~ ~ =t ~I:C; Zi Ln Ln Ln Ln Ln Ln ~ ~ O vl vi vi ~ vl vi . .
C~ 3: Z; ~ i vi vi ~i ~, :, .' . ~ ~
H ~ !:
c~ rl ~ ~ ~ ~ ~ ~ .~
~4 Q. td ,D C) rd a) ~ ' . , ~ oc) ~ 00 00 CO ` ,'~

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C> V
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45 ~ 328 . .

..:
; As can be seen, there is a dramatic decrease in ., .
electrochemical activity as the drying temperature is in-oreased o~er 70C. It is believed that, even though the Ni304 2H20 does not convert to a cubic inactive form until about 130C, interlaminar bonding in the battery material starts to occur above about 60C-70C; and that this along with interlaminar water loss apparently makes the material dried over about 65C lneffective as a battery material.
What exactly happens is not completely understood at this time; it is known, howeuer, that when the electrode material, containing a mixture of Ni (II) and Ni (III) , forms, and which is believed to have a stoichiometry of i nickel hydrated oxide Ni304 2H20, is dried at temperatures over 65C~ it becomes progressively inactive and is not useful as a battery material. lt is critical then that the active material of this invention only be dried between about 15C-65C and preferably at 25Co At the higher temperatures of about 65C a high humid~ty environment could be used to minimize interlaminar water lossO
The infrared and Raman spectra o~ the fully hydro-lyzed product, contalning nickel forms which correspond to a i, .. .
stoichiometry of N1304 2H20, when dr~ed below 65C~ shows a center of symmetry and layer-like -O-Ni-ONi-O-Ni-O- structure with water molecules dispersed in interlaminar positions.
The crystalline layer structure is hexagonal and belongs to the same group Dd3(P3m).
Unexpectedly, only the Na202 + Ni3 reaction pro-duct, when the components are reacted within critical weight percent, temperature and time ranges, and when combined with critical weight percent Co during fusion, during hydrolysis 5 . .

'` 45,328 ~ ~

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~ 33~ ::
. -~ ~ .
after hydrolysis or a~ter plaque pasting, provides suitable .
high performance active battery material for use in making - battery electrode plates. This active material~ formed by hydrolyzing NaNiO2 and adding about 2-12 wt% Co based on NiO
plus Co has a capacity of at least 0~185 amp-hr/gram. When it is used in a metallic plaque it provides an electrode thak can be alternately stacked in a container opposite negative electrodes, such as ~or example electrodes containing iron active battery material, with separators therebetween and a suitable caustic electrolyte contacting the electrodes and separators, with suitable electrical connections, to provide a battery.

- ~ ..

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'

Claims (21)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of producing a battery electrode plate containing active battery material, comprising the steps of:
(a) mixing NiO with Na202 in a weight ratio of NiO:Na202 of between about 1:1.35 to about 1:2.1;
(b) heating the mixture of NiO and Na202 between about 800°C-1150°C, for about 1/2-8 hours to melt the mixture and to form NaNiO2;
(c) hydrolyzing the NaNiO2 in water at between about 20°C-95°C to form active battery material and then washing the active battery material;
(d) maintaining the activity of the battery mater-ial by maintaining the temperature of the material below about 65°C; and (e) applying the battery material to a porous metallic plaque.

2. The method of claim 1 wherein the NiO is sub-stantially pure, and cobalt, selected from the group consist-ing of Co, Co203, Co304 and CoO and their mixtures is added to the materials.

3. The method of claim 1 wherein the NiO is sub-stantially pure, and cobalt additive as substantially pure cobalt hydroxide is added after hydrolysis of the reaction product comprising NaNiO2.

4. The method of claim 1 wherein cobalt addi-tive as a water soluble cobalt salt is added during hydrolysis of the reaction product comprising NaNiO2.

5. The method of claim 1 wherein cobalt addi-tive as a water soluble cobalt salt is added after hydrolysis.

6. The method of claim 1 wherein cobalt additive as a water soluble cobalt salt is added after applying the battery material to the porous metallic plaque.

7. A method of producing a battery electrode plate containing active battery material, comprising the steps of:
(a) mixing an admixture of NiO and cobalt material selected from the group consisting of Co, Co203, Co304 and CoO and their mixtures and Na202, wherein the weight ratio of NiO:Na202 is between about 1:1.35 to about 1:2.1 and the amount of Co in the cobalt material is between about 2-12 wt% based on NiO plus Co content;
(b) heating the admixture at a temperature between about 800°C-1150°C for about 1/2-8 hours to melt the :
admixture and provide a reaction product consisting essentially of NaNiO2 and NaCoO2 then cooling the reaction product;
(c) hydrolyzing the reaction product in water at between about 20°C-95°C, forming an active battery material;
(d) washing the active battery material and then maintaining the activity of the battery material by maintaining the temperature of the material below 65°C; and (e) applying the active battery material to a metallic plaque to provide a battery electrode.

8. The method of claim 7, wherein the reaction product is hydrolyzed in water, the active battery material contains from about 0.5 to 5 wt% unreacted NaNiO2 and NaCoO2 and the active battery material is dried between about 15°C-65°C after step (d).

9. The method of claim 7, wherein the admixture in step (b) is heated at a temperature of between about 850°C-1100°C for between about 1/2-8 hours to melt the mixture and the NiO, cobalt material and Na202 are in substantially pure form.

10. The method of claim 8, wherein the reaction product is cooled to a temperature below about 95°C before step (c), and the water used in the hydrolysis step has a temperature of between about 20°C-95°C.

11. The method of claim 8, wherein the reaction product is cooled to between about 20°-95°C before step (c), the water used in the hydrolysis step has a temperature of between about 20°C-35°C, the active battery material com-prises Ni hydroxide forms which have a weight ratio of Ni (II) hydroxide:Ni (III) hydroxide of over 1:2 and the active battery material is washed after hydrolysis until neutral to litmus.

12. The method of claim 11, wherein the reaction product is hydrolyzed by immersion in water and the NiO, cobalt material and Na202 contain no more than 5% impurities selected from the group consisting of mercury, silver, cadmium, lead, magnesium, chromium, calcium, zirconium and barium compounds.

13. The method of claim 11, wherein the amount of Co in the mixture of step (a) is between about 4-8 wt%, the active battery material Ni hydroxide forms comprise a mater-ial having a stoichimetry of Ni304 . 2H20, and the active battery material is applied to the metallic plaque in aqueous slurry form.

14. The method of claim 13, wherein the metallic plaque is between 90-95% porous and comprises relatively smooth contacting metal fibers.

15. The method of claim 14, wherein the metal fibers are diffusion bonded before coating, wherein there is only an interdiffusion of atoms across the fibers interface.

16. A method of making an active battery electrode powder, comprising the steps of:
(a) mixing an admixture of NiO and Na202, wherein the weight ratio of NiO:Na202 is between about 1:1.35 to about 1:201;
(b) heating the admixture of a reaction temperature of between about 800°-1150°C, for about 1/2-8 hours to melt the admixture and form a reaction product comprising NaNiO2;
(c) hydrolyzing the reaction product comprising NaNiO2 in water of between 20°-95°C, forming a battery material comprising Ni hydroxide forms and then washing the battery material; and (d) maintaining the activity of the battery material by maintaining the temperature of the material below 65°C.

17. The method of claim 16 wherein cobalt addi-tive selected from the group of Co, Co203, Co304 and CoO and their mixtures is mixed with the nickel oxide and Na202 in step (a) providing a battery material with about 2-12 wt% Co based on NiO plus Co content and the battery material is dried between about 15°C-65°C after step (c).

18. The method of claim 17 wherein the mixture of nickel oxide, cobalt additive and Na202 is heated at a temperature of between about 850°C-1100°C for between about 1/2-8 hours to melt the mixture, and the nickel oxide 9 cobalt additive and Na202 are in substantially pure form.

19. The method of claim 17 wherein the Ni hydroxide forms comprise a material having a stoichiometry of Ni304 .
2H20, said material after drying being in crystalline layer form with interlaminar water.

20. me method of claim 19 wherein the crystalline structure of the material after drying has a center of sym-metry and layer like -O-Ni-O-Ni-O-Ni 0- structure with water molecules dispersed in interlaminar positions.

21. A method of making an active battery electrode powder, comprising the steps of:
(a) mixing NiO and Na202 in a weight ratio of NiO:Na202 of between about 1:1.35 to about 1:2.1;
(b) heating the mixture at a temperature between about 800°C-1150°C, for about 1/2-8 hours to melt the mixture and to form NaNiO2;
(c) hydrolyzing the NaNiO2 in water at between about 20°C-95°C to form a battery material and then washing the battery material;
(d) maintaining the activity of the battery material by maintaining the temperature of the material below 65°C.