Abstract: The present invention relates to a method of producing particles having a particle size of less than 100 nm and surface areas of at least 20 m2/g where the particles are free from agglomeration. The method involves synthesizing the particles within an emulsion having a 1-40% water content to form reverse micelles. In particular, the particles formed are metal oxide particles. The particles can be used to oxidize hydrocarbons, particularly methane.

Abstract: This invention relates to a process for preparing a 3R1-type crystalline anionic clay comprising the steps of:

Abstract: A new family of crystalline metal oxide compositions have been synthesized. These compositions are described by the empirical formula: AnTaMxM′yM″mOp where A is an alkali metal cation, ammonium ion and mixtures thereof, M is tungsten, molybdenum, or mixtures thereof. M′ is vanadium, antimony, tellurium, niobium and mixtures thereof, and M″ is titanium, tin, indium and gallium, aluminum, bismuth and mixtures thereof. M′ and M″ are optional metals. These compositions are characterized by having an x-ray diffraction pattern having at least one peak at a d spacing of about 3.9 Å. These materials can be used in various hydrocarbon conversion processes such as dehydrogenation.

Abstract: A cathode material for a lithium secondary battery having a high capacity, an excellent cycle property, and an excellent thermal stability. The cathode material for the lithium secondary battery is a layered compound having a general formula: LixNi1-a-b-c-dCOaM1bM2cM3dO2, wherein M1, M2, M3 are selected from Ti, Mg, B and Al and wherein the characters x, a, b, c and d respectively satisfy 1.0≦x≦1.2; 0.3≦a≦0.3; 0.005≦b≦0.1; 0.005≦c≦0.1; 0.005≦d≦0.1; and 0.115≦a+b+c+d≦0.

Abstract: The method of the present invention involves the in situ formation of metal-molybdate catalyst particles active for methanol oxidation to formaldehyde, with iron as an example, the catalyst is made by mixing particulate forms of Fe2O3 and MoO3 which form an active Fe2(MoO4)3/MoO3 component inside the reactor during methanol oxidation.

Abstract: The present invention relates to a method of producing particles having a particle size of less than 100 nm and surface areas of at least 20 m2/g where the particles are free from agglomeration. The method involves synthesizing the particles within an emulsion having a 1-40% water content to form reverse micelles. In particular, the particles formed are metal oxide particles. The particles can be used to oxidize hydrocarbons, particularly methane.

Abstract: A process to produce mixed metal oxides and metal oxide compounds. The process includes evaporating a feed solution that contains at least two metal salts to form an intermediate. The evaporation is conducted at a temperature above the boiling point of the feed solution but below the temperature where there is significant crystal growth or below the calcination temperature of the intermediate. The intermediate is calcined, optionally in the presence of an oxidizing agent, to form the desired oxides. The calcined material can be milled and dispersed to yield individual particles of controllable size and narrow size distribution.

Abstract: There can be provided a positive electrode active material for a secondary battery which is excellent in the charging and discharging cycle characteristics so that it retains high battery capacity that is comparable to the hitherto known LiNiO2 even by increasing the number of cycle, which has an improved cycle property (stability) at high temperature and which is a complex oxide represented by the general formula (I) LiyNi1−xCox1Mx2O2  (I) (wherein M represents at least one element selected from the group consisting of Al, Fe, Mn and B, y represents 0.9≦y≦1.3, x represents 0<x≦0.5, x1 represents 0<x1<0.5, x1+x2 x, when M is at least one element of Al, Fe and Mn, x2 represents 0<x2≦0.3, when M is B, x2 is 0<x2≦0.1, when M is the combination of B and at least one element of Al, Fe and Mn, x2 represents 0<x2<0.3 but the ratio occupied by B therein is in a range of from 0 to 0.1).

Abstract: LDH-osmate of the formula [MII(1−x)MIIIx(OH)2][OsO42−]x/2.zH2O wherein MII is a divalent cation selected from the group consisting of Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+ and Ca2+ and MIII is a trivalent ion selected from the group consisting of Al3+, Cr3+, Mn3+, Fe3+ and Co3+, and x is the mole fraction having integral value ranging from 0.2 to 0.33, and z is the number of water molecules and ranges from 1 to 4, useful as, a catalyst, and a process for the preparation thereof and use thereof to manufacture vicinal diols.

Abstract: A non-aqueous electrolyte cell having improved cyclic characteristics at elevated temperatures. The non-aqueous electrolyte cell includes a positive electrode, a negative electrode and a non-aqueous electrolyte. The positive electrode contains, as a positive electrode active material, a lithium transition metal composite oxide represented by the general formula LiCoxAyBzO2 where A denotes at least one selected from the group consisting of Al, Cr, V, Mn and Fe, B denotes at least one selected from the group consisting of Mg and Ca and x, y and z are such that 0.9≦x<1, 0.001≦y≦0.05 and 0.001≦z≦0.05.

Abstract: An &agr;-lithium aluminate obtained through a solid-phase reaction of a &ggr;-alumina and a lithium compound, wherein said &agr;-lithium aluminate comprises particles having a round shape, with a BET specific surface area in the range of 4-7 m2/g, and substantially not including &ggr;-lithium aluminate. Further, said &agr;-lithium aluminate is manufactured by dry-mixing a &ggr;-alumina having a BET specific surface area in the range of 70-140 m2/g and a lithium compound, and then baking and reacting said compound in solid-phase.

Abstract: Positive electrode-active materials for use in lithium-ion and lithium-ion polymer batteries contain quaternary composite oxides of manganese, nickel, cobalt and aluminum where one of the four is present at levels of over 70 mol percent. The composite oxides can be lithiated to form positive electrode-active materials that are stable over at least ten charge/discharge cycles at voltage levels over 4.8 volts, and have capacities of over 200 mAh/g. Methods for producing the materials and electrochemical cells and batteries that include the materials are also provided.

Abstract: A process for preparing a spinel lithium manganese complex oxide having the general formula LixMn2−yAlyO4 (wherein 0.9≦x≦1.1, and 0.002≦y≦0.5) the process comprising the steps of reacting a manganese complex hydroxide represented by the general formula (IIa) Mn2+(1−a)Al3+a(OH)[2+a−nz](An−)2·mH2O (wherein An− is an anion having a valence n, 0.001≦a≦0.25, 0.03<z<0.3 and 0<m) with a water-soluble lithium compound in a molar ratio of Li/(Mn+Al) of 0.45˜0.55 in an aqueous medium to obtain a slurry, spray- or freeze-drying the obtained slurry, and heating the resultant dry material at a temperature of 600˜900° C.

Abstract: The invention relates to lithium mixed oxide particles coated with one or more layers of alkali metals and metal oxides for improving the properties of electrochemical cells.

Abstract: Tantalum and niobium aluminate mixed metal oxides may be made by a process comprising mixing a first metal compound selected from the group consisting of aluminum alkoxide, aluminum beta-diketonate, aluminum alkoxide beta-diketonate, and mixtures thereof with a second metal compound selected from the group consisting of niobium alkoxide, niobium beta-diketonate, niobium alkoxide beta-diketonate, tantalum alkoxide, tantalum beta-diketonate, tantalum alkoxide beta-diketonate, and mixtures thereof to provide a precursor and then hydrolyzing the mixture. The resulting mixed metal oxide may be used in a variety of components of integrated circuits.

Abstract: Tantalum and niobium aluminate mixed metal oxides may be made by a process comprising mixing a first metal compound selected from the group consisting of aluminum alkoxide, aluminum beta-diketonate, aluminum alkoxide beta-diketonate, and mixtures thereof with a second metal compound selected from the group consisting of niobium alkoxide, niobium beta-diketonate, niobium alkoxide beta-diketonate, tantalum alkoxide, tantalum beta-diketonate, tantalum alkoxide beta-diketonate, and mixtures thereof to provide a precursor and then hydrolyzing the mixture. The resulting mixed metal oxide may be used in a variety of components of integrated circuits.

Abstract: Novel, fine particulate synthetic chalcoalumite, process for preparation thereof, and a heat insulating agent and agricultural film containing said fine, particulate synthetic chalcoalumite. The above objects are met by synthetic chalcoalumite represented by formula (1) below: (M12+)a−x(M22+)Al3+4(OH)b(An−)c. mH2O  (1)  (in which M12+ stands for Zn2+ or Cu2+,  M22+ is at least one divalent metal ion selected from Ni2+, Co2+, Cu2+, Zn2+ and Mg2+,  a is 0.3<a<2.0 (with the proviso that M1 and M2 are not the same),  x is 0 ≦x<1.0, and x<a  b is 10<b<14,  An− is at least one selected from SO42−, HPO42−, CO32−, SO32−, HPO32−, NO3−, H2PO4−, Cl−, OH− and silicate ion,  c is 0.4<c<2.

Abstract: The invention features an MgAl2O4 spinel powder having a specific surface area of 40 m2/g or more and an average diameter of from 3 to 20 &mgr;m and having uniform pores, and a slurry containing this spinel powder. The spinel powder is produced by milling (1) an MgAl2O4 spinel powder obtained by synthesizing by the coprecipitation method with the use of hydroxide materials wherein the ratio of the average diameter of aluminum hydroxide “D1” to the average diameter of magnesium hydroxide “D2” satisfies the requirement 1.85≦(D1/D2) or 0.5>(D1/D2) and calcining, (2) an MgAl2O4 spinel powder obtained by drying a mixture solution containing water-soluble organic substance having a boiling point of 120° C.

Abstract: &ggr;-type lithium aluminate, a particle of which has a BET specific surface area in a range of from 1 to 15 m2/g and a synthesized degree (P) of not less than 80% is disclosed. The synthesized degree (P) is defined by the equation, (I2/I1)×100, wherein I1 and I2 represent diffraction intensity in the X-ray diffraction spectral analysis of &ggr;-type lithium aluminate and I1 represents the height of a (101) peak, I2 represents the height of a (200) peak. The &ggr;-type lithium aluminate of the present invention exhibits excellent heat stability and chemical stability in a molten carbonate when used for an electrolyte-retainer plate of MCFC.

Abstract: A process for producing positive electrode active material includes feeding an aqueous nickel salt solution, aqueous solutions of different kinds of metals, aqueous solution containing ammonium ions and aqueous alkali solution each independently and simultaneously into a reaction vessel such that the amount of alkali metal is 1.9-2.3 moles relative to 1 mole of the total amount of nickel and different kinds of metals and the amount of ammonium ions is 2 moles or more relative to 1 mole of the total amount of nickel and different kinds of metals, the pH in the vessel is 11-13, the temperature in the vessel is 30-60° C. and the average residence time is 20-50 hours.

Abstract: Disclosed is a high-efficiency stress-luminescent material capable of emitting luminescence by receiving a mechanical stress such as compression, shearing and rubbing. The stress-luminescent material is an alkaline earth aluminate of a non-stoichiometric composition deficient in the content of the alkaline earth element by 0.01 to 20% by moles from stoichiometry. The efficiency of stress-luminescence emission can be further enhanced when the non-stoichiometric alkaline earth aluminate contains 0.01 to 10% by moles of rare earth metal ions or transition metal ions. The stress-luminescent material is prepared by subjecting a non-stoichiometric composite oxide of aluminum oxide and an alkaline earth oxide to a calcination treatment at 800 to 1700° C. in a reducing atmosphere.

Abstract: There can be provided a positive electrode active material for a secondary battry which is excellent in the charging and discharging cycle characteristics so that it retains high battery capacity that is comparable to the hitherto known LiNiO2 even by increasing the number of cycle, which has an improved cycle property (stability) at high temperature and which is a complex oxide represented by the general formula (I)

Abstract: The present invention provides a slurry composition for chemical mechanical polishing comprising spinel particles having the formula AO•xZ2O3 wherein A is at least one divalent cation, Z is at least one trivalent cation, and 0.01≦x≦100. The present invention also includes a method of chemical mechanical polishing the surface of a substrate using slurry compositions that include these spinel particles. The slurry compositions of the present invention provide the desired level of planarization and selectivity for both metal and oxide surfaces. In addition, the slurry compositions of the invention can be prepared such that they are substantially free of alpha phase alumina particles and other high hardness particles to produce a scratch-free polished surface.

Abstract: A non-metallic product (NMP) substantially free of metallic aluminum and aluminum nitride which is utilized for making calcium aluminate.

Abstract: A spinel-type structure with the general formula Li[Ti1.67Li0.33−yMy]O4, for 0<y≦0.33, where M=Mg and/or Al. The structure is usefid as a negative electrode for a non-aqueous electrochemical cell and in a non-aqueous battery comprising an plurality of cells, electrically connected, each cell comprising a negative electrode, an electrolyte and a positive electrode, the negative electrode consisting of the spinel-type structure disclosed.

Abstract: A method has been developed for the solution-based metal exchange of carboxylato-alumoxanes [Al(O)x(OH)y(O2CR)z]n with a wide range of metal cations. Metal-exchanged carboxylato-alumoxanes are new, particularly those in which about 10% to about 50% or more of the Al ions are exchanged for other metal ions. Additionally, the carboxylic acid ligands can be stripped from the boehmite core of metal-exchanged carboxylato-alumoxanes at low temperature leading to the formation of metal-exchanged boebmite particles. These new material phases can be used as intermediates for preparation of mixed metal aluminum oxide materials. Thermolysis of the metal-exchanged carboxylato-alumoxanes or metal-exchanged boehmite particles results in doped aluminas (M/Al2O3), binary (MAlOx), ternary (MM′AlOx) and even more complex metal aluminum oxide compounds, where M and M′ are metal ions other than those of aluminum and are preferably those of Lanthanide metals or transition metals.

Abstract: A lithium-containing complex metal oxide having a crystal structure of &agr;-NaFeO2 type and represented by a general formula: LiaNiXCoYAlZO2 wherein 0.96≦a≦1.06, 0.70≦X<0.85, 0.05≦Y≦0.20, 0.10<Z≦0.25, and 0.98≦(X+Y+Z)≦1.02, and further wherein a separation between a peak position of (018) face and a peak position of (110) face in the powder X-ray diffraction pattern of said metal oxide using CuK&agr;-ray is in the range of from 0.520 to 0.700° as expressed in terms of &Dgr;2&thgr;((110)-(018)).

Abstract: Hydrated aluminium compounds of the present invention are represented by the general formula nS, mM, Al2O3, xH2O where S is a surfactant or a group of surfactants, n is the number of moles of S, M is an alkaline cation, preferably selected from the group formed by Na+, K+, NH4+, m is the number of moles of M and x is the number of moles of water. The hydrated compounds are obtained from inorganic aluminium sources which are in the form of cation-monomers and/or cation-oligomers. The surfactants are anionic and/or non-ionic surfactants. When the group of surfactants comprises at least one anionic surfactant, at least one cationic surfactant can optionally be added.

Abstract: Lithium composite metal oxides prepared by mixing at least one type of hydroxides, oxides, and carbonates of a metal selected from the group of transition metal, IIA metal, and IIIA metal, and a lithium compound of which the D50 value is in the range 5 to 50 &mgr;m, the D90 value is 90 &mgr;m or smaller, and in which particles 100 &mgr;m or greater do not exist, and calcining in the temperature range 700 to 1000° C. for 2 to 30 hours, and grinding, are used as the active material of a positive electrode which is laminated with a negative electrode with a separator interposed and spirally wound thereby forming an electrode group. By using the positive active materials prepared in this manner, discharge capacity and cycle characteristic of a non-aqueous electrolyte secondary cell can be improved.

Abstract: A continuous fiber of titania are made having an average diameter per a monofilament of from 5 to 50 &mgr;m, which has a BET specific surface area of 10 m2/g or more, a pore volume of 0.05 cc/g or more, a volume of pores having a pore diameter of not less than 10 angstroms being 0.02 cc/g or more and an average tensile strength per a monofilament of 0.1 GPa or more, or which has an average tensile strength per a monofilament of 0.5 GPa or more.

Abstract: A process for producing high-purity hydrotalcites by reacting alcohols or alcohol mixtures with at least one or more divalent metal(s) and at least one or more trivalent metal(s) and hydrolysing the resultant alcoholate mixture with water. The corresponding metal oxides can be produced by calcination.

Abstract: The invention is a sol-gel processed metal-aluminum based oxide material useful as a catalyst including a NOx trapping catalyst. It is made from alkoxides comprising heterometallic alkoxides. The metal is transition metal, one or both of alkali metal and alkaline earth metal, and optionally also a lanthanide. Then invention is also a method of treating lean-burn internal combustion engine exhaust gas with this material, without any precious metal included with the material, in the exhaust gas system. The method comprises locating the NOx trap in the system where the NOx trap absorbs nitrogen oxides during lean cycle operation and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust gas is lowered as during a rich or stoichiometric cycle.

Abstract: Processes for use of a controlled continuous high pressure multiple reactant streams flowing into a chemical mixer/reactor. Individual reactant streams are pressurized to about 8,000 to 50,000 psi and achieve velocities up to about 250 meters/second in the final stage of the chemical mixer/reactor.

Abstract: This invention is a single phase metal alumina material made by sol-gel techniques from certain heterometallic alkoxides which include aluminum and at least alkali metals, and optionally alkaline earth metals and lanthanide.

Abstract: A process for producing positive electrode active material includes feeding an aqueous nickel salt solution, aqueous solutions of different kinds of metals, aqueous solution containing ammonium ions and aqueous alkali solution each independently and simultaneously into a reaction vessel such that the amount of alkali metal is 1.9-2.3 moles relative to 1 mole of the total amount of nickel and different kinds of metals and the amount of ammonium ions is 2 moles or more relative to 1 mole of the total amount of nickel and different kinds of metals, the pH in the vessel is 11-13, the temperature in the vessel is 30-60.degree. C. and the average residence time is 20-50 hours.

Abstract: A method of producing a homogeneous metal oxide fiber having high denseness and free of voids that may adversely affect the electro-optic characteristic of the fiber, and a metal oxide fiber produced according to the method. The method comprises:a first step of forming a gel-form fiber from a sol obtained by concentrating a solution composed of a metallic compound, water and a solvent to the extent that the solution exhibits a spinnable behavior;a second step of decomposing and eliminating organic components out of the gel-form fiber obtained at the first step; anda third step of solidifying the gel-form fiber obtained at the second step;the second step and/or the third step being carried out while heating is made in a water vapor atmosphere.

Abstract: A process is described for removing dissolved silica from an alkaline solution containing sodium aluminate, e.g. a Bayer process solution. The process comprises contacting the alkaline solution with a slowly stirred bed of particles comprising coarse silica sand or a mixture of coarse silica sand and particles of sodalite, whereby the dissolved silica is precipitated out of solution to form a precipitation of desilication product dispersed in the solution and separating the desilication product solids from the alkaline solution to obtain a desilicated alkaline solution.

Abstract: There are disclosed lithium-iron oxide particles having an excellent properties such as electrochemical reversibility and suitable as a material for cathode active material for lithium ion batteries, which have a corrugated layer crystal structure and are represented by the general formula (1):Li.sub.x (Fe.sub.(1-y) M.sub.y)O.sub.2 (1)wherein x is more than 0 and not more than 1; y is 0.005 to 0.1; and M is at least one metal selected from the group consisting of Co, Ni, Mn and Al.

Abstract: The mixed powders of a lithium compound and a transition metal based compound are formed into shaped parts, which are packed to form a bed 6 on a porous plate 5 in the bottom of a reaction vessel 7 placed on a support 10 in a firing furnace 8 equipped with an electric heater; the packed parts are fired with an oxidizing gas such as air being forced through the bed 6 at a superficial velocity higher than a specified value via a gas feed pipe 3 connecting an air pump 1, a flow regulator 2 and a preheater 4 and the gas emerging from the bed 6 is discharged into the air atmosphere through a ventilation port 9. Even if increased amounts of the mixed powders have to be fired, the invention process enables the production of a lithium complex oxide as an active material that is homogeneous and which features excellent cell characteristics.

Abstract: A material for a negative electrode having excellent performance for doping lithium and de-doping lithium and a nonaqueous-electrolyte secondary battery having a large capacity are provided. The nonaqueous-electrolyte secondary battery is disclosed which has a negative electrode mainly composed of a compound containing at least any one of silicon, germanium and tin, nitrogen and oxygen, a positive electrode made of composite metal oxide containing lithium or an interlayer compound containing lithium and nonaqueous electrolyte.

Abstract: There is provided a novel lithium nickel complex oxide represented by the general formula:Li.sub.y-x1 Ni.sub.1-x2 M.sub.x O.sub.2wherein M represents one selected from the group consisting of Al, Fe, Co, Mn and Mg, x=x.sub.1 +x.sub.2, O<x.sub.1 .ltoreq.0.2, O<x.sub.2 .ltoreq.0.5, 0<x.ltoreq.0.5, and 0.9.ltoreq.y.ltoreq.1.3, and wherein the crystals have been sufficiently developed and are highly purified, and a positive electrode active material for a secondary battery whose stability of high discharge capacity is excellent.

Abstract: The present invention provides a process for producing aluminum oxide fibers and, particularly, a process for producing aluminum fibers that have a high aspect ratio and can be accurately aligned, said process for producing aluminum oxide fibers comprising the steps of: uniformly mixing an aluminum or aluminum alloy powder with a boron oxide powder or a powder which, upon heating, can be converted to a boron oxide powder; and heating the mixed powder, or comprising the steps of: mixing not more than 50% by weight, in terms of titanium, of a titanium or titanium alloy powder to the starting mixture; and heating the mixed powder.

Abstract: A process for producing alumina hydrates having a boehmite structure is provided. These alumina hydrates are dispersible in water. The boehmite or pseudoboehmite in colloids having a pH value of between 3 and 7 is present in a nanocrystalline form (<4 nm) whereby an exceptionally high translucence is imparted to the colloid.

Abstract: Semi-crystalline alumina compositions with framework mesopores are disclosed. The compositions are assembled from inorganic aluminum precursors and nonionic polyethylene oxide surfactants. The new assembly pathway introduces several new concepts to alumina mesostructure synthesis. The application of low-cost, non-toxic and biodegradable surfactants and low cost aluminum reagents as alumina precursors which are inorganic and low solution reaction temperatures, introduces efficient and environmentally clean synthetic techniques to the formation of mesostructures. Recovery of the surfactant can be achieved through solvent extraction where the solvent may be water or ethanol or by calcination.

Abstract: A titanium compound for photochemical reactions having a high catalytic activity per unit surface area and extremely good stability to heat treatment is made of a substitutional solid solution of titanium oxide in which aluminum atoms occupy titanium sites of the titanium oxide uniformly at a predetermined ratio. Aluminum atoms preferably occupy about 0.01 to 0.5% of the titanium sites. The titanium compound for photochemical reactions is obtained from a complex alkoxide of titanium and aluminum.

Abstract: This invention aims to provide titanate whiskers which are excellent in heat resistance, chemical resistance and reinforcing effect and are low in coefficient of thermal conductivity.The titanate whiskers of the invention are those represented by the formulaA.sup.I.sub.v A.sup.II.sub.w M.sup.II.sub.x M.sup.III.sub.y Ti.sub.8-z O.sub.16wherein A.sup.I is at least one member selected from alkali metals, A.sup.II is Ba, M.sup.II is at least one member selected from the group consisting of Mg, Co, Ni, Zn, Cu and Mn, M.sup.III is at least one member selected from the group consisting of Al, Sc, Cr, Fe and Ga, and v, w, x, y and z are real numbers which fulfill 0.5.ltoreq.2x+y.ltoreq.2.5, 2x+y=v+2w, and z=x+y.

Abstract: The present invention provides a hollow oxide particle including a shell wall constituting a hollow room, and the shell wall has a thickness of 20 nm or less. The shell wall may be mainly composed from at least one selected from the group consisting of alumina, spinel, iron oxides, yttrium oxides, and titanium oxides. A process for producing the hollow oxide particle comprises the steps of: forming a Water in Oil (W/O) type emulsion including aqueous microspheres having a each diameter of 100 nm or more, by adding an organic solvent to an aqueous solution dissolving and/or suspending at least one of metal salts and metal compounds; and forming the hollow oxide particle by atomizing the Water in Oil (W/O) type emulsion to burn. When the hollow oxide particle is brought into contact with a water-containing solution, a surface of the shell wall may have a minutely irregular surface.

Abstract: A method of improving certain vanadium oxide formulations is presented. The method concerns fluorine doping formulations having a nominal formula of LiV.sub.3 O.sub.8. Preferred average formulations are provided wherein the average oxidation state of the vanadium is at least 4.6. Herein preferred fluorine doped vanadium oxide materials, electrodes using such materials, and batteries including at least one electrode therein comprising such materials are provided.

Abstract: A positive active material for lithium battery, includes a lithium-containing amorphous nickel oxide represented by a chemical composition formula of Li.sub.x NiO.sub.2 ; wherein x is from greater than 0.25 to 2. Preferably, x is from greater than 1 to 2. More preferably, x is from greater than 1.4 to 2. The positive active material may contains cobalt from 2 to 60 mol % {(Co/(Ni+Co)}.

Abstract: A process for producing a stable acidic aqueous alumina sol containing 50 to 300 nm of elongate secondary particles which are elongated in only one plane and formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length of one side of 10 to 30 nm when observed through an electron microscope, the process comprises the steps of:(A) adding an alkali to an aqueous alumina sol containing fibrous colloidal particles of an amorphous alumina hydrate to produce a reaction mixture having a pH of 9 to 12,(B) subjecting the reaction mixture obtained in the step (A) to a hydrothermal treatment at a temperature of 110 to 250.degree. C. to produce an aqueous suspension containing an alumina hydrate having a boehmite structure, and(C) desalting the aqueous suspension obtained in the step (B) by adding water and an acid by ultrafiltration to form an acidic aqueous alumina sol having a pH of 3 to 6.