Patent Description:
Lithiated transition metal oxides are currently being used as electrode active materials for lithium-ion batteries. Extensive research and developmental work has been performed in the past years to improve properties like charge density, specific energy, but also other properties like the reduced cycle life and capacity loss that may adversely affect the lifetime or applicability of a lithium-ion battery. Additional effort has been made to improve manufacturing methods.

Many electrode active materials discussed today are of the type of lithiated nickel-cobalt-manganese oxide ("NCM materials") or lithiated nickel-cobalt-aluminum oxide ("NCA materials").

In a typical process for making cathode materials for lithium-ion batteries, first a so-called precursor is being formed by co-precipitating the transition metals as carbonates, oxides or preferably as hydroxides that may or may not be basic. The precursor is then mixed with a lithium salt such as, but not limited to LiOH, Li<NUM>O or - especially - Li<NUM>CO<NUM> - and calcined (fired) at high temperatures. Lithium salt(s) can be employed as hydrate(s) or in dehydrated form. The calcination - or firing - generally also referred to as thermal treatment or heat treatment of the precursor - is usually carried out at temperatures in the range of from <NUM> to <NUM>. During the thermal treatment a solid state reaction takes place, and the electrode active material is formed. In cases hydroxides or carbonates are used as precursors the solid state reaction follows a removal of water or carbon dioxide. The thermal treatment is performed in the heating zone of an oven or kiln.

In order to improve the capacity of cathode active materials, it has been suggested to select as high a nickel content as possible. However, in materials such as LiNiO<NUM>, it has been observed that poor cycle life, pronounced gassing and a strong increase of the internal resistance during cycling provide high challenges for a commercial application.

Document <CIT> discloses a lithium-magnesium-nickel-titanium-manganese composite oxide cathode material represented by a chemical formula (Li<NUM>+x-2yMy) (NimTinMn<NUM>-m-n)<NUM>-xO<NUM>, wherein M represents Mg, and x, y, m and n are numbers that satisfy <NUM>≤x≤<NUM>, <NUM><y<<NUM>, <NUM><m<<NUM> and <NUM>≤n≤<NUM>.

Accordingly, the particulate material as defined at the outset has been found, hereinafter also defined as inventive material or as material according to the current invention. The inventive material shall be described in more detail below.

Inventive material has a composition according to the formula (LiaMgb)<NUM>+x(NicM<NUM>dM<NUM>e)<NUM>-xO<NUM> wherein.

This corresponds to the formula (LiaMgb)<NUM>+xTM<NUM>-xO<NUM> wherein TM is (Ni<NUM>-x1-x2M<NUM>x1M<NUM>x2) with x1 ≥ <NUM> and x2 ≥ <NUM> and x1 + x2 ≤ <NUM>.

The inventive material will be described in more detail below.

In one embodiment of the present invention, inventive material is comprised of spherical particles, that are particles having a spherical shape. Spherical particles shall include not just those which are exactly spherical but also those particles in which the maximum and minimum diameter of at least <NUM>% (number average) of a representative sample differ by not more than <NUM>%.

The inventive material has an average particle diameter (D50) in the range of from <NUM> to <NUM>, preferably from <NUM> to <NUM>. The average particle diameter can be determined, e. , by light scattering or LASER diffraction or electroacoustic spectroscopy. The particles are usually composed of agglomerates from primary particles, and the above particle diameter refers to the secondary particle diameter.

In one embodiment of the present invention, the inventive material is comprised of secondary particles that are agglomerates of primary particles. Preferably, the inventive material is comprised of spherical secondary particles that are agglomerates of primary particles. Even more preferably, inventive material is comprised of spherical secondary particles that are agglomerates of spherical primary particles or platelets.

In one embodiment of the present invention, primary particles of inventive material have an average diameter in the range from <NUM> to <NUM>, preferably from <NUM> to <NUM>, particularly preferably from <NUM> to <NUM>. The average primary particle diameter can, for example, be determined by SEM or TEM. SEM is an abbreviation of scanning electron microscopy, TEM is an abbreviation of transmission electron microscopy, and XRD stands for X-ray diffraction.

In one embodiment of the present invention, the inventive material has a specific surface (BET), hereinafter also referred to as "BET surface", in the range of from <NUM> to <NUM><NUM>/g. The BET surface may be determined by nitrogen adsorption after outgassing of the sample at <NUM> for <NUM> minutes or more and beyond this in accordance with DIN ISO <NUM>:<NUM>.

M<NUM> is selected from Ti, Zr, Nb, Mo, and W, and combinations of at least two of the aforementioned, preferably M<NUM> is selected from combinations of at least two of Ti, Zr, Nb, Mo, and W, for example combinations of Ti and Zr or combinations of Zr and Mo or combinations of Ti and Zr and Mo.

M<NUM> is selected from Al, Co and Mn and combinations of at least two of the aforementioned,.

Some metals are ubiquitous metals such as sodium, calcium or zinc, but such traces will not be taken into account in the description of the present invention. Traces in this context will mean amounts of <NUM> mol-% or less, referring to the total metal content TM. Preferably, the calcium content of inventive material is only traces, and no compound of calcium is deliberately added during manufacture.

In one embodiment of the present invention, said material comprises a combination of metals according to formula (I).

M<NUM> is selected from Nb, Ti, Zr, W, and Mo and preferably from combinations of at least two of the aforementioned, and M<NUM> is selected from Al, Mn, and Co and combinations of at least two of the aforementioned.

In one embodiment of the present invention, M<NUM> is selected from Ti, Zr and W, and combinations of two of the aforementioned.

In one embodiment of the present invention the number of metals other than Ni, Mg and Li is at least three and at most five. More preferably, only one element M<NUM> is present.

In one embodiment of the present invention, metal(s) M<NUM> is/are each present in a molar percentage with reference to Ni in the range of from <NUM> to <NUM>.

In one embodiment of the present invention, metal(s) M<NUM> are each present in a molar percentage with reference to Ni in the range of from <NUM> to <NUM>.

In one embodiment of the present invention, M<NUM> and M<NUM> are homogeneously dispersed within the inventive material. That means that M<NUM> and M<NUM> are about uniformly distributed over the particles of inventive material.

In one embodiment of the present invention, at least one of M<NUM> and M<NUM> are enriched in the particle boundaries of particles of inventive material.

In a specific embodiment of the present invention, secondary particles of inventive material are coated with a metal oxide, preferably with a metal oxide that does not serve as a cathode active material. Examples of suitable metal oxides are LiBO<NUM>, B<NUM>O<NUM>, Al<NUM>O<NUM>, Y<NUM>O<NUM>, LiAlO<NUM>, TiO<NUM>, ZrO<NUM>, Li<NUM>ZrO<NUM>, Nb<NUM>O<NUM>, and LiNbO<NUM>.

Inventive materials are particularly suitable as cathode active materials for lithium ion batteries. They combine good cycling stability with a high energy density.

In one embodiment of the present invention inventive cathode active material contains in the range of from <NUM> to <NUM> % by weight Li<NUM>CO<NUM>, determined by titration as Li<NUM>CO<NUM> and referring to said inventive material.

Another aspect of the present invention relates to a process for making inventive materials, hereinafter also referred to as inventive process or process according to the (present) invention. The inventive process comprises several steps, hereinafter also referred to as step (a), step (b) etc..

Steps (a) to (c) are characterized as follows:.

Steps (a) to (c) are described in more detail below.

In step (a), a particulate nickel hydroxide, nickel (II) oxide or nickel oxyhydroxide is provided, hereinafter altogether also referred to as nickel oxide/hydroxide. In the context of the present invention, the term nickel oxyhydroxide is not limited to stoichiometric NiOOH but to any compound of nickel that bears only oxide and hydroxide counterions and a maximum individual content of impurities of <NUM>% by weight of metals such as Mn or Mg, referring to the total metal content of said nickel hydroxide, nickel (II) oxide or nickel oxyhydroxide. Preferably, nickel hydroxide, nickel (II) oxide or nickel oxyhydroxide has a maximum total impurity content of <NUM>% by weight, referring to the total metal content of said nickel hydroxide, nickel (II) oxide or nickel oxyhydroxide.

The nickel oxide/hydroxide provided in step (a) has an average particle diameter (D50) in the range of from <NUM> to <NUM>, preferably from <NUM> to <NUM>. The average particle diameter can be determined, e. , by light scattering or LASER diffraction or electroacoustic spectroscopy. The particles may be composed of agglomerates from primary particles, and the above particle diameter refers to the secondary particle diameter.

A preferred nickel oxide/hydroxide is freshly precipitated nickel hydroxide.

In one embodiment of the present invention, the nickel oxide/hydroxide provided in step (a) has a residual moisture content in the range of from <NUM> to <NUM>,<NUM> ppm, preferably from <NUM> to <NUM> ppm. The residual moisture content may be determined by Karl-Fischer titration.

In step (b), said nickel oxide/hydroxide is mixed with compounds of Mg and M<NUM> and M<NUM>, in the absence of solvents such as water or organic solvents.

Suitable compounds of Mg are Mg(OH)<NUM>, MgO, Mg(NO<NUM>)<NUM>, and oxalates such as MgC<NUM>O<NUM>.

Suitable compounds of M<NUM> are oxides, (oxy)hydroxides and nitrates of Ti, of Zr, of W, of Mo, and of Nb, such as TiO<NUM>, Ti<NUM>O<NUM>, TiO(OH)<NUM>, ZrO<NUM>, Zr(OH)<NUM>, TiO(NO<NUM>)<NUM>, Ti(NO<NUM>)<NUM>, niobic acid, Nb<NUM>O<NUM>, WO<NUM>, Li<NUM>WO<NUM>, and MoO<NUM>. Further examples of compounds of M<NUM> are for instance but not limited to ammonium metatungstate (hydrate), ammonium orthomolybdate, ammonium heptamolybdate, ammonium dimolybdate, ammonium niobate oxalate, ammonium zirconium (IV) carbonate, either as such or as hydrates.

Suitable compounds of M<NUM> are nitrates, oxides, hydroxides and oxyhydroxides, for example Al<NUM>O<NUM>, Al(OH)<NUM>, AlOOH, Al<NUM>(SO<NUM>)<NUM>, KAl(SO<NUM>)<NUM>, and Al(NO<NUM>)<NUM>, alkanolates of Al such as, but not limited to Al(C<NUM>H<NUM>O)<NUM>, Al-tris-isopropoxide, mixed salts of at least <NUM> cations such as aluminum magnesium isopropoxide. Examples of compound of cobalt are Co(OH)<NUM>, Co<NUM>O<NUM>, Co<NUM>O<NUM>, and examples of compounds of Mn are Mn<NUM>O<NUM>, MnO<NUM>, and Mn(NO<NUM>)<NUM>. Alkanolates of M<NUM> are possible as well.

In addition, a source of lithium is added.

Examples of sources of lithium are Li<NUM>O, LiOH, and Li<NUM>CO<NUM>, each water-free or as hydrate, if applicable, for example LiOH·H<NUM>O. Preferred example is lithium hydroxide.

The amounts of source of lithium and of powdery residue is selected in a way that the molar ratio of Li and TM is (<NUM>+x) to <NUM>, with x being in the range of from <NUM> to <NUM>.

Said source of lithium is preferable in particulate form, for example with an average diameter (D50) in the range of from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

In one embodiment of the present invention, step (b) is performed at a temperature in the range of from <NUM> to <NUM>, preferred are <NUM> to <NUM>.

In one embodiment of the present invention, step (b) is performed at normal pressure. It is preferred, though, to perform step (b) under elevated pressure, for example at <NUM> mbar to <NUM> bar above normal pressure, or with suction, for example <NUM> to <NUM> mbar below normal pressure, preferably <NUM> to <NUM> mbar below normal pressure.

Step (b) may be performed, for example, in a vessel that can be easily discharged, for example due to its location above a filter device. Such vessel may be charged with nickel oxide/hydroxide from step (a) followed by introduction of source of lithium and of compounds of Mg and M<NUM> and M<NUM>. In another embodiment, such vessel is charged with source of lithium and with compounds of Mg and M<NUM> and M<NUM> followed by introduction of nickel oxide/hydroxide from step (a). In another embodiment, nickel oxide/hydroxide from step (a) and compounds of Mg and M<NUM> and M<NUM> and source of lithium are introduced simultaneously.

Mixing of the nickel oxide/hydroxide with the compounds of Mg and M<NUM> and M<NUM> and the source of lithium may take place over a period of from <NUM> minute to <NUM> hours, preferably from <NUM> minutes to <NUM> hour, even more preferably from <NUM> to <NUM> minutes.

Step (b) may be supported by mixing operations, for example shaking or in particular by stirring or shearing, see below.

A powdery mixture is obtained from step (b).

Examples of suitable apparatuses for performing step (b) are high-shear mixers, tumbler mixers, plough-share mixers and free fall mixers.

In one embodiment of the present invention, step (b) is performed at a temperature in the range of from ambient temperature to <NUM>, preferably <NUM> to <NUM>.

Step (c) includes subjecting said mixture from step (b) to a thermal treatment. Examples of step (c) are heat treatments at a temperature in the range of from <NUM> to <NUM>, preferably <NUM> to <NUM>. The terms "treating thermally" and "heat treatment" are used interchangeably in the context of the present invention.

In one embodiment of the present invention, the mixture obtained from step (b) is heated to <NUM> to <NUM> with a heating rate of <NUM> to <NUM>/min.

In one embodiment of the present invention, the temperature is ramped up before reaching the desired temperature of from <NUM> to <NUM>, preferably <NUM> to <NUM>. For example, first the mixture obtained from step (c) is heated to a temperature to <NUM> to <NUM> and then held constant for a time of <NUM> to <NUM> hours, and then it is raised to <NUM> up to <NUM> and then held at <NUM> to <NUM> for <NUM> minutes to <NUM> hours.

In one embodiment of the present invention, step (c) is performed in a roller hearth kiln, a pusher kiln or a rotary kiln or a combination of at least two of the foregoing. Rotary kilns have the advantage of a very good homogenization of the material made therein. In roller hearth kilns and in pusher kilns, different reaction conditions with respect to different steps may be set quite easily. In lab scale trials, box-type and tubular furnaces and split tube furnaces are feasible as well.

In one embodiment of the present invention, step (c) is performed in an oxygen-containing atmosphere, for example in a nitrogen-air mixture, in a rare gas-oxygen mixture, in air, in oxygen or in oxygen-enriched air. In a preferred embodiment, the atmosphere in step (c) is selected from air, oxygen and oxygen-enriched air. Oxygen-enriched air may be, for example, a <NUM>:<NUM> by volume mix of air and oxygen. Other options are <NUM>:<NUM> by volume mixtures of air and oxygen, <NUM>:<NUM> by volume mixtures of air and oxygen, <NUM>:<NUM> by volume mixtures of air and oxygen, and <NUM>:<NUM> by volume mixtures of air and oxygen.

In one embodiment of the present invention, step (c) is performed under a stream of gas, for example air, oxygen and oxygen-enriched air. Such stream of gas may be termed a forced gas flow. Such stream of gas may have a specific flow rate in the range of from <NUM> to <NUM><NUM>/h·kg material according to general formula (LiaMgb)<NUM>+x(NicM<NUM>dM<NUM>e)<NUM>-xO<NUM>. The volume is determined under normal conditions: <NUM> Kelvin and <NUM> atmosphere. Said stream of gas is useful for removal of gaseous cleavage products such as water and carbon dioxide.

The inventive process may include further steps such as, but not limited, additional calcination steps at a temperature in the range of from <NUM> to <NUM> subsequently to step (c).

In one embodiment of the present invention, step (c) has a duration in the range of from one hour to <NUM> hours. Preferred are <NUM> to <NUM> hours. The time at a temperature above <NUM> is counted, heating and holding but the cooling time is neglected in this context.

A material is obtained that is excellently suitable as cathode active material for lithium ion batteries.

In one embodiment of the present invention, it is possible to treat inventive material with water and subsequently drying it. In another embodiment, it is possible to at least partially coat particles of inventive material, for example by mixing it with an oxide or hydroxide, for example with aluminum hydroxide or alumina or with boric acid, followed by thermal treatment at <NUM> to <NUM>. In another embodiment of the present invention, it is possible to at least partially coat particles of inventive material by way of atomic layer deposition methods, for example by alternating treatment(s) with trimethylaluminum and moisture.

A further aspect of the present invention are electrodes comprising at least one inventive material. They are particularly useful for lithium ion batteries. Lithium ion batteries comprising at least one electrode according to the present invention exhibit a very good discharge and cycling behavior, and they show good safety behavior.

In one embodiment of the present invention, inventive cathodes contain.

In a preferred embodiment of the present invention, inventive cathodes contain.

percentages referring to the sum of (A), (B) and (C).

Cathodes according to the present invention contain carbon in electrically conductive modification, in brief also referred to as carbon (B). Carbon (B) can be selected from soot, active carbon, carbon nanotubes, graphene, and graphite. Carbon (B) can be added as such during preparation of electrode materials according to the invention.

Electrodes according to the present invention can comprise further components. They can comprise a current collector (D), such as, but not limited to, an aluminum foil. They further comprise a binder material (C), hereinafter also referred to as binder (C). Current collector (D) is not further described here.

Suitable binders (C) are preferably selected from organic (co)polymers. Suitable (co)polymers, i.e. homopolymers or copolymers, can be selected, for example, from (co)polymers obtainable by anionic, catalytic or free-radical (co)polymerization, especially from polyethylene, polyacrylonitrile, polybutadiene, polystyrene, and copolymers of at least two comonomers selected from ethylene, propylene, styrene, (meth)acrylonitrile and <NUM>,<NUM>-butadiene. Polypropylene is also suitable. Polyisoprene and polyacrylates are additionally suitable. Particular preference is given to polyacrylonitrile.

In the context of the present invention, polyacrylonitrile is understood to mean not only polyacrylonitrile homopolymers but also copolymers of acrylonitrile with <NUM>,<NUM>-butadiene or styrene. Preference is given to polyacrylonitrile homopolymers.

In the context of the present invention, polyethylene is not only understood to mean homo-polyethylene, but also copolymers of ethylene which comprise at least <NUM> mol% of copolymerized ethylene and up to <NUM> mol% of at least one further comonomer, for example α-olefins such as propylene, butylene (<NUM>-butene), <NUM>-hexene, <NUM>-octene, <NUM>-decene, <NUM>-dodecene, <NUM>-pentene, and also isobutene, vinylaromatics, for example styrene, and also (meth)acrylic acid, vinyl acetate, vinyl propionate, C<NUM>-C<NUM>-alkyl esters of (meth)acrylic acid, especially methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, <NUM>-ethylhexyl acrylate, n-butyl methacrylate, <NUM>-ethylhexyl methacrylate, and also maleic acid, maleic anhydride and itaconic anhydride. Polyethylene may be HDPE or LDPE.

In the context of the present invention, polypropylene is not only understood to mean homopolypropylene, but also copolymers of propylene which comprise at least <NUM> mol% of copolymerized propylene and up to <NUM> mol% of at least one further comonomer, for example ethylene and α-olefins such as butylene, <NUM>-hexene, <NUM>-octene, <NUM>-decene, <NUM>-dodecene and <NUM>-pentene. Polypropylene is preferably isotactic or essentially isotactic polypropylene.

In the context of the present invention, polystyrene is not only understood to mean homopolymers of styrene, but also copolymers with acrylonitrile, <NUM>,<NUM>-butadiene, (meth)acrylic acid, C<NUM>-C<NUM>-alkyl esters of (meth)acrylic acid, divinylbenzene, especially <NUM>,<NUM>-divinylbenzene, <NUM>,<NUM>-diphenylethylene and α-methylstyrene.

Another preferred binder (C) is polybutadiene.

Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethylcellulose, polyimides and polyvinyl alcohol.

In one embodiment of the present invention, binder (C) is selected from those (co)polymers which have an average molecular weight Mw in the range from <NUM>,<NUM> to <NUM>,<NUM>,<NUM>/mol, preferably to <NUM>,<NUM>/mol.

Binder (C) may be cross-linked or non-cross-linked (co)polymers.

In a particularly preferred embodiment of the present invention, binder (C) is selected from halogenated (co)polymers, especially from fluorinated (co)polymers. Halogenated or fluorinated (co)polymers are understood to mean those (co)polymers which comprise at least one (co)polymerized (co)monomer which has at least one halogen atom or at least one fluorine atom per molecule, more preferably at least two halogen atoms or at least two fluorine atoms per molecule. Examples are polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), tetrafluoroethylene-hexafluoropropylene copolymers, vinylidene fluoride-hexafluoropropylene copolymers (PVdF-HFP), vinylidene fluoride-tetrafluoroethylene copolymers, perfluoroalkyl vinyl ether copolymers, ethylene-tetrafluoroethylene copolymers, vinylidene fluoride-chlorotrifluoroethylene copolymers and ethylene-chlorofluoroethylene copolymers.

Suitable binders (C) are especially polyvinyl alcohol and halogenated (co)polymers, for example polyvinyl chloride or polyvinylidene chloride, especially fluorinated (co)polymers such as polyvinyl fluoride and especially polyvinylidene fluoride and polytetrafluoroethylene.

Inventive electrodes may comprise <NUM> to <NUM>% by weight of binder(s) (d), referring to the sum of component (a), component (b) and carbon (c).

A further aspect of the present invention is a battery, containing.

Embodiments of cathode (<NUM>) have been described above in detail.

Anode (<NUM>) may contain at least one anode active material, such as carbon (graphite), TiO<NUM>, lithium titanium oxide, silicon or tin. Anode (<NUM>) may additionally contain a current collector, for example a metal foil such as a copper foil.

Electrolyte (<NUM>) may comprise at least one non-aqueous solvent, at least one electrolyte salt and, optionally, additives.

Nonaqueous solvents for electrolyte (<NUM>) can be liquid or solid at room temperature and is preferably selected from among polymers, cyclic or acyclic ethers, cyclic and acyclic acetals and cyclic or acyclic organic carbonates.

Examples of suitable polymers are, in particular, polyalkylene glycols, preferably poly-C<NUM>-C<NUM>-alkylene glycols and in particular polyethylene glycols. Polyethylene glycols can here comprise up to <NUM> mol% of one or more C<NUM>-C<NUM>-alkylene glycols. Polyalkylene glycols are preferably polyalkylene glycols having two methyl or ethyl end caps.

The molecular weight Mw of suitable polyalkylene glycols and in particular suitable polyethylene glycols can be up to <NUM>,<NUM>,<NUM>/mol, preferably up to <NUM>,<NUM>,<NUM>/mol.

Examples of suitable cyclic organic carbonates are compounds of the general formulae (II) and (III)
<CHM>
<CHM>
where R<NUM>, R<NUM> and R<NUM> can be identical or different and are selected from among hydrogen and C<NUM>-C<NUM>-alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, with R<NUM> and R<NUM> preferably not both being tert-butyl.

Electrolyte (<NUM>) further comprises at least one electrolyte salt. Suitable electrolyte salts are, in particular, lithium salts. Examples of suitable lithium salts are LiPF<NUM>, LiBF<NUM>, LiClO<NUM>, LiAsFe, LiCF<NUM>SO<NUM>, LiC(CnF2n+<NUM>SO<NUM>)<NUM>, lithium imides such as LiN(CnF2n+<NUM>SO<NUM>)<NUM>, where n is an integer in the range from <NUM> to <NUM>, LiN(SO<NUM>F)<NUM>, Li<NUM>SiF<NUM>, LiSbF<NUM>, LiAlCl<NUM> and salts of the general formula (CnF2n+<NUM>SO<NUM>)tYLi, where m is defined as follows:.

In a preferred embodiment of the present invention, electrolyte (<NUM>) contains at least one flame retardant. Useful flame retardants may be selected from trialkyl phosphates, said alkyl being different or identical, triaryl phosphates, alkyl dialkyl phosphonates, and halogenated trialkyl phosphates. Preferred are tri-C<NUM>-C<NUM>-alkyl phosphates, said C<NUM>-C<NUM>-alkyls being different or identical, tribenzyl phosphate, triphenyl phosphate, C<NUM>-C<NUM>-alkyl di- C<NUM>-C<NUM>-alkyl phosphonates, and fluorinated tri-C<NUM>-C<NUM>-alkyl phosphates,.

In a preferred embodiment, electrolyte (<NUM>) comprises at least one flame retardant selected from trimethyl phosphate, CH<NUM>-P(O)(OCH<NUM>)<NUM>, triphenylphosphate, and tris-(<NUM>,<NUM>,<NUM>-trifluoroethyl)phosphate.

Electrolyte (<NUM>) may contain <NUM> to <NUM>% by weight of flame retardant, based on the total amount of electrolyte.

In an embodiment of the present invention, batteries according to the invention comprise one or more separators (<NUM>) by means of which the electrodes are mechanically separated. Suitable separators (<NUM>) are polymer films, in particular porous polymer films, which are unreactive toward metallic lithium. Particularly suitable materials for separators (<NUM>) are polyolefins, in particular film-forming porous polyethylene and film-forming porous polypropylene.

Separators (<NUM>) composed of polyolefin, in particular polyethylene or polypropylene, can have a porosity in the range from <NUM> to <NUM>%. Suitable pore diameters are, for example, in the range from <NUM> to <NUM>.

In another embodiment of the present invention, separators (<NUM>) can be selected from among PET nonwovens filled with inorganic particles. Such separators can have a porosity in the range from <NUM> to <NUM>%. Suitable pore diameters are, for example, in the range from <NUM> to <NUM>.

Batteries according to the invention can further comprise a housing which can have any shape, for example cuboidal or the shape of a cylindrical disk. In one variant, a metal foil configured as a pouch is used as housing.

Batteries according to the invention provide a very good discharge and cycling behavior, in particular at high temperatures (<NUM> or higher, for example up to <NUM>) in particular with respect to the capacity loss.

Batteries according to the invention can comprise two or more electrochemical cells that combined with one another, for example can be connected in series or connected in parallel. Connection in series is preferred. In batteries according to the present invention, at least one of the electrochemical cells contains at least one electrode according to the invention. Preferably, in electrochemical cells according to the present invention, the majority of the electrochemical cells contain an electrode according to the present invention. Even more preferably, in batteries according to the present invention all the electrochemical cells contain electrodes according to the present invention.

The present invention further provides for the use of batteries according to the invention in appliances, in particular in mobile appliances. Examples of mobile appliances are vehicles, for example automobiles, bicycles, aircraft or water vehicles such as boats or ships. Other examples of mobile appliances are those which move manually, for example computers, especially laptops, telephones or electric hand tools, for example in the building sector, especially drills, battery-powered screwdrivers or battery-powered staplers.

The present invention is further illustrated by working examples.

Average particle diameters (D50) were determined by dynamic light scattering ("DLS"). Percentages are % by weight unless specifically noted otherwise. All thermal processes were performed under an oxygen flow rate of <NUM> liters per minute in the furnace.

<NUM>): A spherical Ni(OH)<NUM> precursor was obtained by combining aqueous nickel sulfate solution (<NUM> mol/kg solution) with an aqueous <NUM> wt. % NaOH solution and using ammonia as complexation agent. The pH value was set at <NUM>. The freshly precipitated Ni(OH)<NUM> was washed with water, sieved and dried at <NUM> for <NUM> hours. <NUM> was Ni(OH)<NUM> with a D50 of <NUM>.

Manufacture of a comparative cathode active material, C-CAM. <NUM>:
Comparative cathode material C-CAM. <NUM> (Li<NUM>Ni<NUM>Al<NUM>Co<NUM>Mn<NUM>Zr<NUM>O<NUM>) was synthesized by mixing the precursor p-CAM. <NUM> with the lithium source LiOH·H<NUM>O and dopant precursors (Co<NUM>O<NUM>, Al<NUM>O<NUM>, Zr(OH)<NUM>, MnO<NUM>) in appropriate stoichiometric ratios in a ball mill for <NUM> hours. The mixture was then poured into a zirconia crucible and heated from <NUM> to <NUM> at <NUM>/min, and then held at <NUM> for <NUM> hours. The mixture was then heated from <NUM> to <NUM> at <NUM>/min, and then held at <NUM> °C for <NUM> hours. Finally, the fixture was cooled from <NUM> to <NUM> at a cooling rate of more than <NUM>/min and then transferred to a glovebox to obtain the comparative material C-CAM. <NUM> with a d50 of <NUM>.

<NUM>): the precursor p-CAM. <NUM> was mixed with the lithium source LiOH·H<NUM>O and the sources of Mg, M<NUM> and M<NUM>: Mg(OH)<NUM>, Al<NUM>O<NUM>, Co<NUM>O<NUM>, MnO<NUM>, Zr(OH)<NUM>, WO<NUM>) in appropriate stoichiometric ratios in a ball mill for <NUM> hours.

<NUM>): The mixture obtained from (b. <NUM>) was then poured into a zirconia crucible and heated from <NUM> to <NUM> at <NUM>/min, and then held at <NUM> for <NUM> hours. The mixture was then heated from <NUM> to <NUM> at <NUM>/min, and then held at <NUM> for <NUM> hours. Finally, the fixture was cooled from <NUM> to <NUM> at a cooling rate of more than <NUM>/min and transferred to a glovebox to obtain the inventive material CAM. <NUM> with a d50 of <NUM>°µm. Inventive cathode material CAM. <NUM> (Li<NUM>Mg<NUM>)Ni<NUM>Al<NUM>Co<NUM>MnN<NUM>Zr<NUM>W<NUM>O<NUM>) was obtained.

Electrode manufacture: Electrodes contained <NUM>% CAM, <NUM>% carbon black (Super C65) and <NUM>% binder (polyvinylidene fluoride, Solef <NUM>). CAM, carbon black and binder were slurried in N-methyl-<NUM>-pyrrolidone and cast onto aluminum foil by doctor blade. After drying of the electrodes <NUM> at <NUM> in vacuo, circular electrodes were punched, weighed and dried at <NUM> under vacuum for <NUM> hours before entering in an Ar filled glove box.

Half-Cell Electrochemical Measurements: Coin-type electrochemical cells, were assembled in an argon-filled glovebox. The positive <NUM> diameter (loading <NUM>±<NUM> cm-<NUM>) electrode was separated from the <NUM> thick Li foil by a glass fiber separator (Whatman GF/D). An amount of <NUM>µl of <NUM> LiPF<NUM> in ethylene carbonate (EC): ethylmethyl carbonate (EMC), <NUM>:<NUM> by weight, was used as the electrolyte. Cells were galvanostatically cycled at a Maccor <NUM> battery cycler between <NUM> and <NUM> V at room temperature by applying the following C-rates until <NUM> % of the initial discharge capacity is reached at a certain discharge step:.

After charging at the listed C-rates, all charge steps except the first were finished by a constant voltage step (CV*) for <NUM>, or until the current reached <NUM>.

During the resistance measurement (conducted every <NUM> cycles at <NUM>), the cell was charged at <NUM> C to reach <NUM>% state of charge, relative to the previous discharge capacity. To equilibrate the cell, a <NUM> open circuit step followed. Finally, a <NUM> C discharge current was applied for <NUM> to measure the resistance. At the end of the current pulse, the cell was again equilibrated for <NUM> in open circuit and further discharged at <NUM> C to <NUM>.

To calculate the resistance, the voltage before applying the <NUM> C pulse current, V0s, and after <NUM> of <NUM> C pulse current, V30 s, as well as the <NUM> C current value, (j in A), were taken. The resistance was calculated according to Eq. <NUM> (V: voltage, j: <NUM>. 5C pulse current).

The results show an improvement in the 1C rate and a higher stability after <NUM> (1C) and <NUM> (<NUM>,1C) cycles. In addition, the resistance growth is less compared to the comparative experiment.

Claim 1:
Particulate material of the composition (LiaMgb)<NUM>+x(NicM<NUM>dM<NUM>e)<NUM>-xO<NUM> wherein
M<NUM> is selected from Ti, Zr, Nb, Mo, and W, and combinations of at least two of the aforementioned,
M<NUM> is selected from Al, Co and Mn and combinations of at least two of the aforementioned,
a : b is in the range of from <NUM>:<NUM> to <NUM>:<NUM>, and a + b = <NUM>,
c : d is in the range of from <NUM>:<NUM> to <NUM>:<NUM>, and c : e is in the range of from <NUM>:<NUM> to <NUM>:<NUM>,
and c + d + e = <NUM>,
total molar ratio of (Li + Mg) to (Ni + M<NUM> + M<NUM>) is in the range of from <NUM>:<NUM> to <NUM>:<NUM>,<MAT>
wherein said particulate material has an average particle diameter (D50) in the range of from <NUM> to <NUM>.