CA2165259A1 - Lithium- and manganese(iii/iv)-containing spinels - Google Patents
Lithium- and manganese(iii/iv)-containing spinelsInfo
- Publication number
- CA2165259A1 CA2165259A1 CA002165259A CA2165259A CA2165259A1 CA 2165259 A1 CA2165259 A1 CA 2165259A1 CA 002165259 A CA002165259 A CA 002165259A CA 2165259 A CA2165259 A CA 2165259A CA 2165259 A1 CA2165259 A1 CA 2165259A1
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- manganese
- lithium
- iii
- spinel
- cathode material
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G45/00—Compounds of manganese
- C01G45/12—Manganates manganites or permanganates
- C01G45/1221—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G45/00—Compounds of manganese
- C01G45/12—Manganates manganites or permanganates
- C01G45/1221—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof
- C01G45/1242—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/30—Three-dimensional structures
- C01P2002/32—Three-dimensional structures spinel-type (AB2O4)
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Secondary Cells (AREA)
Abstract
Lithium- and manganese(III/IV)-containing spinels are prepared by reacting stoichiometric amounts of a lithium compound, of a man-ganese compound and, if required, of a further metal compound at from 200 to 800°C under conditions under which the manganese as-sumes an average oxidation state of from 3.5 to 4.0, by a process which comprises carrying out the reaction with mixing of the reactants.
Spinels which have a novel morphology and can be used as cathode material in electrochemical cells can be obtained.
Spinels which have a novel morphology and can be used as cathode material in electrochemical cells can be obtained.
Description
- 216525~
i .. --Lithium- and manganese(III/IV)-containing spinels The present invention relates to a process for the preparation of lithium- and manganese(III/IV)-containing spine~s by reacting stoichiometric amounts of a lithium compound, of a manganese com-pound and, if required, of a further metal compound at from 200 to 800 C under conditions under which the manganese assumes an average oxidation state of from 3.5 to 4Ø
The present invention furthermore relates to spinels of this type having novel morphology, their use as cathode material for elec-trochemical cells and electrochemical cells which contain these spinels as cathode material.
Lithium- and manganese(III/IV)-containing spinels and the use of such compounds as cathode material in electrochemical cells are generally known, for example from DE-A 4328755.
20 In the stoichiometrically simplest case of LiMn2O4, the manganese is present in an average oxidation state of 3.5 in these spinels.
These spinels undergo reversible reaction with compounds which are capable of incorporating lithium cations in their lattice, such as graphite, with elimination of the small lithium atoms from the crystal lattice, manganese(III) ions being oxidized to manganese(IV) ions in said lattice. This reaction can be used in an electrochemical cell for storing electric power by separating the compound (anode material) which takes up lithlum ions and the 30 manganese spinel by an electrolyte through which the lithium cat-ions migrate from the spinel into the anode material.
To charge the cell, electrons flow through an external voltage source and lithium cations through the electrolyte from the spinel to the anode material. During the use of the cell, the lithium cations flow through the electrolyte, whereas the elec-trons flow through an effective resistance from the anode material to the spinel.
40 However, it is not only the spinel LiMn2Og which is suitable for this reaction but also, as is generally known, spinels having further metal cations and other valencies.
Further metals A are, for example, cobalt and nickel, which partly replace the manganese and the lithium in the lattice or which may be incorporated additionally in the lattice. By means of these cations A, the electrical properties of an Li-Mn cell _ 2 can be modified, for example with regard to the voltage and the voltage drop.
As described, for example, in DE-A 4328755, these spinels are prepared batchwise by reacting a lithium compound, a manganese compound and, if required, a further metal compound at elevated temperatures in a solid-state diffusion reaction which is known to be very slow.
10 Milling of the powder in an inert solvent has been described for shortening the reaction times to 48-96 hours at from 300 to 750 C.
In spite of the technical complexity, however, only poor space-time yields can be achieved owing to the long reaction times and the milling step.
It is an object of the present invention to provide an economical and technically simple process for the preparation of lithium-and manganese(III/IV)-containing spinels.
We have found that this object is achieved by a process for the preparation of the above-mentioned spinels by reacting stoichio-metric amounts of a lithium compound, of a manganese compound and, if required, of a further metal compound at from 200 to 800 C
under conditions under which the manganese assumes an oxidation state of from 3.5 to 4.0, which comprises carrying out the reac-tion with mixing of the reactants.
We have also found novel spinels of this type, their use as cath-30 ode material for electrochemical cells and electrochemical cells which contain them as cathode material.
The process can be carried out using known apparatuses in which solid-state reactions are carried out with mixing of the reac-tants. For example, rotating bulbs, screw conveyors and in par-ticular rotary tubular furnaces are suitable.
The rotary tubular furnaces preferably contain rotating baffles, by means of which the reactants are thoroughly mixed, scraped off 40 the inner wall of the tube and at the same transported through the tube in the direction of the axis of rotation of the tube.
Furnaces having rotating drums and the correspondingly stationary baffles are also possible. Further details of these reaction ap-paratuses, which must be provided with the required heating means, are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., VCH Verlagsgesellschaft mbH, ` - 216~2S9 Weinheim, 1992, Vol. B4, pages 107-111, so that further state-ments in this context are unnecessary.
The reaction is carried out at from 200 to 800 C, in particular from 400 to 750 C, resulting in reaction times of from 0.5 to 10, preferably from 0.5 to 6, in particular from 1 to 4, hours.
The lithium compounds used may be lithium oxide or substances which decompose under the reaction conditions into lithium-con-10 taining oxides, such as inorganic lithium salts, for examplelithium nitrate, lithium hydroxide or, preferably, lithium car-bonate, organic lithium compounds, such as lithium carboxylates, for example lithium acetate, lithium laurate, lithium tartrate or, preferably, lithium oxalate, or lithium-containing complexes, such as lithium acetylacetonate. Mixtures of such compounds are also suitable.
Suitable manganese compounds are substances which are converted under the reaction conditions into manganese(III/IV)-containing 20 oxides, such as inorganic manganese salts, for example manga-nese(II) hydroxide, manganese(III) hydroxide, manganese(IV) hydroxide, manganese(II) nitrate, manganese oxides or, prefer-ably, manganese(II) carbonate, organic manganese compounds, such as manganese carboxylates, for example manganese(II) acetate, manganese(III) acetate, manganese(II) tartrate, manganese(II) citrate or, preferably, manganese(II) oxalate, manganese-contain-ing complexes, for example manganese(II) acetylacetonate, or mix-tures of such compounds.
30 It is also possible to use mixed lithium- and manganese-contain-ing compounds, as can be obtained in a manner known per se, for example from a solution containing a lithium compound and a man-ganese compound, by coprecipitation or removal of the solvent.
If compounds of divalent manganese are used as starting materi-als, as is preferred, the presence of oxygen-containing oxidizing agents is required, for example of manganese dioxide or, most simply, of air. If, on the other hand, a manganese compound hav-ing a higher valency is used, a corresponding amount of an Mn(II) 40 compound or a reducing agent, such as carbon monoxide, is expedi-ently concomitantly used, or the manganese valency is most simply established by means of the oxygen partial pressure of an oxygen-containing gas.
_ 4 If the spinel is to contain heteroatoms, the corresponding amounts of oxides or salts of these metals are concomitantly used in the novel process.
In general, the spinels are preferably of the formula I
LiX (Mnn)2 Ay Oz where x is from 0.5 to 1.6, n is the average oxidation state of the manganese in the range from 3.5 to 4.0, A is one equivalent of a metal cation, y is from 0 to 0.4 and z is the number of oxygen equivalents determined by the amount of the other components.
Particularly suitable metal equivalents A are those of cobalt and 20 nickel. They are preferably used in oxidic form or in the form of salts with the same anions as the lithium and manganese salts.
Mixtures of such compounds are also suitable.
A lithium compound, a manganese compound and, if required, a fur-ther metal compound can be introduced separately into the reac-tion apparatus or advantageously mixed before the reaction.
If the oxalate is used as the lithium compound and in particular as the manganese compound, spinels are obtained in the form of 30 previously unknown, preferably elongated particles which have axial ratios (length/width) of from 2:1 to 20:1, in particular from 3:1 to 10:1, and are particularly suitable as cathode material in electrochemical parts because they can be more readily dispersed in the conventional preparation of the cathode material.
With regard to the use of the spinels as cathode material in electrochemical cells, products shown to be single-phase by X-ray analysis are desirable for achieving good cycling behavior, the 40 cycling behavior being understood as meaning the reversible elec-trochemical incorporation of lithium ions into, or elimination of lithium ions from, the spinel lattice with compensation of the charge by a change in the oxidation state of the manganese or of the further metal ions which may be present.
_ 5 In accordance with the process according to the invention, spi-nels having widely varying specific surface areas can be produced by appropriate selection of the reaction conditions and starting materials. For example, spinels having high specific surface areas (measured in accordance with DIN 66 132) such as 5 to 12 m2/g can be obtained, as well as spinels with low specific surface areas such as 0.1 to 4 m2/g.
By selecting the specific surface area it is possible to influ-10 ence essential application parameters such as dispersibility, bulk density, packing density in the electrode and the stability of the spinel, in particular against chemical decomposition.
Such products can advantageously be obtained by means of an atom-ic ratio of lithium to manganese of from 0.5:2 to 1.6:2, prefer-ably from 0.8:2 to 1.3:2, in particular from 0.9:2 to 1.12:2, and usually have a capacitance of from 100 to 140 mAh/g.
For the preparation of the cathode material, the spinels are pro-20 cessed in a manner known per se.
In electrochemical cells, this cathode material can be used in a manner known per se opposite an anode which takes up lithium cat-ions.
Suitable electrolytes are known to be organic compounds, prefer-ably esters, such as ethylene carbonate and propylene carbonate, or mixtures of such compounds.
30 Such electrochemical cells deliver, as a rule, a voltage of from 3.5 to 4.5 V.
The lithium content of the spinels was determined by atomic ab-sorption spectrometry, the total manganese content was determined as MnzP2O7 after oxidation to manganese(IV) and the content of manganese(III/IV) was determined by reaction with hydrochloric acid and measurement of the chlorine gas formed. The axial ratio (length/width) was determined by means of scanning electron micrographs. The electrical capacitance of the spinels was 40 measured in a manner known per se in a cell having button cell geometry, against a lithium anode with LiC104 in propylene carbonate as electrolyte.
216~259 -_ 6 Examples 1-3 Mixtures of a lithium compound and a manganese compound were reacted with a supply of 200 l/hour of air in a rotating tube which had an internal diameter of 55 mm and a length of 700 mm, heated to 675 C, and which was provided with a static transport screw with webs for thorough mixing of the reaction mixture. The rotary speed of the tube was controlled so that the residence time of the reaction mixture in the heated zone was 2 hours.
The details of these experiments and their results are shown in the table below.
The spinels had a capacitance of 100-110 mAh/g.
The elongated spinels had an axial ratio (length/width) of from 3:1 to 10:1.
Examples 4-15 70 g of mixtures of a lithium compound and a manganese compound were reacted in a 250 ml rotating flask with a supply of 50 l/hour of air. The residence time of the reaction mixture was 2 hours.
The details of these experiments and their results are shown in the table below.
The spinels had a capacitance of 100-110 mAh/g.
Comparative example A mixture of lithium carbonate and manganese carbonate was heated in a crucible for 2 hours at 675 C under air.
A spinel suitable for the preparation of cathode material was not obtained.
The details of this experiment and its result are shown in the ~0 table below.
Table Starting materials Reaction Spinels Li Mn Li/Mn T Li Mn-III Mn-IV Morphology compound compound atom/atom C % by wt. % by wt. % by wt.
Ex. 1 carbonate carbonate 1.10:2 675 4.0 27.0 32.0 isometric Ex. 2 carbonate oxalate1.08:2 675 4.0 27.1 32.2 elongated Ex. 3 oxalate oxalate 1.10:2 675 4.1 25.0 33.6 elongated Ex. 4 carbonate carbonate 1.00:2 650 3.6 26.6 33.8 isometric Ex. 5 carbonate carbonate 1.00:2 675 3.5 34.8 25.2 isometric Ex. 6 carbonate carbonate 1.00:2 700 3.5 36.7 23.8 isometric Ex. 7 carbonate carbonate 1.04:2 650 3.7 30.5 29.1 isometric Ex. 8 carbonate carbonate 1.04:2 675 3.7 31.0 28.7 isometric Ex. 9 carbonate carbonate 1.04:2 700 3.7 32.1 27.7 isometric ~7 Ex. 10 carbonate carbonate 1.08:2 650 3.8 28.3 30.8 isometric Ex. 11 carbonate carbonate 1.08:2 675 3.7 28.8 30.6 isometric r~
Ex. 12 carbonate carbonate 1.08:2 700 3.8 31.0 28.9 isometric CJQ
Ex. 13 carbonate carbonate 1.10:2 650 3.8 28.2 31.3 isometric Ex. 14 carbonate carbonate 1.10:2 675 4.0 28.4 30.7 isometric Ex. 15 carbonate carbonate 1.10:2 700 3.9 30.1 29.3 isometric Comp. carbonate carbonate 1.08:2 675 No spinel suitable as cathode material was Example formed
i .. --Lithium- and manganese(III/IV)-containing spinels The present invention relates to a process for the preparation of lithium- and manganese(III/IV)-containing spine~s by reacting stoichiometric amounts of a lithium compound, of a manganese com-pound and, if required, of a further metal compound at from 200 to 800 C under conditions under which the manganese assumes an average oxidation state of from 3.5 to 4Ø
The present invention furthermore relates to spinels of this type having novel morphology, their use as cathode material for elec-trochemical cells and electrochemical cells which contain these spinels as cathode material.
Lithium- and manganese(III/IV)-containing spinels and the use of such compounds as cathode material in electrochemical cells are generally known, for example from DE-A 4328755.
20 In the stoichiometrically simplest case of LiMn2O4, the manganese is present in an average oxidation state of 3.5 in these spinels.
These spinels undergo reversible reaction with compounds which are capable of incorporating lithium cations in their lattice, such as graphite, with elimination of the small lithium atoms from the crystal lattice, manganese(III) ions being oxidized to manganese(IV) ions in said lattice. This reaction can be used in an electrochemical cell for storing electric power by separating the compound (anode material) which takes up lithlum ions and the 30 manganese spinel by an electrolyte through which the lithium cat-ions migrate from the spinel into the anode material.
To charge the cell, electrons flow through an external voltage source and lithium cations through the electrolyte from the spinel to the anode material. During the use of the cell, the lithium cations flow through the electrolyte, whereas the elec-trons flow through an effective resistance from the anode material to the spinel.
40 However, it is not only the spinel LiMn2Og which is suitable for this reaction but also, as is generally known, spinels having further metal cations and other valencies.
Further metals A are, for example, cobalt and nickel, which partly replace the manganese and the lithium in the lattice or which may be incorporated additionally in the lattice. By means of these cations A, the electrical properties of an Li-Mn cell _ 2 can be modified, for example with regard to the voltage and the voltage drop.
As described, for example, in DE-A 4328755, these spinels are prepared batchwise by reacting a lithium compound, a manganese compound and, if required, a further metal compound at elevated temperatures in a solid-state diffusion reaction which is known to be very slow.
10 Milling of the powder in an inert solvent has been described for shortening the reaction times to 48-96 hours at from 300 to 750 C.
In spite of the technical complexity, however, only poor space-time yields can be achieved owing to the long reaction times and the milling step.
It is an object of the present invention to provide an economical and technically simple process for the preparation of lithium-and manganese(III/IV)-containing spinels.
We have found that this object is achieved by a process for the preparation of the above-mentioned spinels by reacting stoichio-metric amounts of a lithium compound, of a manganese compound and, if required, of a further metal compound at from 200 to 800 C
under conditions under which the manganese assumes an oxidation state of from 3.5 to 4.0, which comprises carrying out the reac-tion with mixing of the reactants.
We have also found novel spinels of this type, their use as cath-30 ode material for electrochemical cells and electrochemical cells which contain them as cathode material.
The process can be carried out using known apparatuses in which solid-state reactions are carried out with mixing of the reac-tants. For example, rotating bulbs, screw conveyors and in par-ticular rotary tubular furnaces are suitable.
The rotary tubular furnaces preferably contain rotating baffles, by means of which the reactants are thoroughly mixed, scraped off 40 the inner wall of the tube and at the same transported through the tube in the direction of the axis of rotation of the tube.
Furnaces having rotating drums and the correspondingly stationary baffles are also possible. Further details of these reaction ap-paratuses, which must be provided with the required heating means, are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., VCH Verlagsgesellschaft mbH, ` - 216~2S9 Weinheim, 1992, Vol. B4, pages 107-111, so that further state-ments in this context are unnecessary.
The reaction is carried out at from 200 to 800 C, in particular from 400 to 750 C, resulting in reaction times of from 0.5 to 10, preferably from 0.5 to 6, in particular from 1 to 4, hours.
The lithium compounds used may be lithium oxide or substances which decompose under the reaction conditions into lithium-con-10 taining oxides, such as inorganic lithium salts, for examplelithium nitrate, lithium hydroxide or, preferably, lithium car-bonate, organic lithium compounds, such as lithium carboxylates, for example lithium acetate, lithium laurate, lithium tartrate or, preferably, lithium oxalate, or lithium-containing complexes, such as lithium acetylacetonate. Mixtures of such compounds are also suitable.
Suitable manganese compounds are substances which are converted under the reaction conditions into manganese(III/IV)-containing 20 oxides, such as inorganic manganese salts, for example manga-nese(II) hydroxide, manganese(III) hydroxide, manganese(IV) hydroxide, manganese(II) nitrate, manganese oxides or, prefer-ably, manganese(II) carbonate, organic manganese compounds, such as manganese carboxylates, for example manganese(II) acetate, manganese(III) acetate, manganese(II) tartrate, manganese(II) citrate or, preferably, manganese(II) oxalate, manganese-contain-ing complexes, for example manganese(II) acetylacetonate, or mix-tures of such compounds.
30 It is also possible to use mixed lithium- and manganese-contain-ing compounds, as can be obtained in a manner known per se, for example from a solution containing a lithium compound and a man-ganese compound, by coprecipitation or removal of the solvent.
If compounds of divalent manganese are used as starting materi-als, as is preferred, the presence of oxygen-containing oxidizing agents is required, for example of manganese dioxide or, most simply, of air. If, on the other hand, a manganese compound hav-ing a higher valency is used, a corresponding amount of an Mn(II) 40 compound or a reducing agent, such as carbon monoxide, is expedi-ently concomitantly used, or the manganese valency is most simply established by means of the oxygen partial pressure of an oxygen-containing gas.
_ 4 If the spinel is to contain heteroatoms, the corresponding amounts of oxides or salts of these metals are concomitantly used in the novel process.
In general, the spinels are preferably of the formula I
LiX (Mnn)2 Ay Oz where x is from 0.5 to 1.6, n is the average oxidation state of the manganese in the range from 3.5 to 4.0, A is one equivalent of a metal cation, y is from 0 to 0.4 and z is the number of oxygen equivalents determined by the amount of the other components.
Particularly suitable metal equivalents A are those of cobalt and 20 nickel. They are preferably used in oxidic form or in the form of salts with the same anions as the lithium and manganese salts.
Mixtures of such compounds are also suitable.
A lithium compound, a manganese compound and, if required, a fur-ther metal compound can be introduced separately into the reac-tion apparatus or advantageously mixed before the reaction.
If the oxalate is used as the lithium compound and in particular as the manganese compound, spinels are obtained in the form of 30 previously unknown, preferably elongated particles which have axial ratios (length/width) of from 2:1 to 20:1, in particular from 3:1 to 10:1, and are particularly suitable as cathode material in electrochemical parts because they can be more readily dispersed in the conventional preparation of the cathode material.
With regard to the use of the spinels as cathode material in electrochemical cells, products shown to be single-phase by X-ray analysis are desirable for achieving good cycling behavior, the 40 cycling behavior being understood as meaning the reversible elec-trochemical incorporation of lithium ions into, or elimination of lithium ions from, the spinel lattice with compensation of the charge by a change in the oxidation state of the manganese or of the further metal ions which may be present.
_ 5 In accordance with the process according to the invention, spi-nels having widely varying specific surface areas can be produced by appropriate selection of the reaction conditions and starting materials. For example, spinels having high specific surface areas (measured in accordance with DIN 66 132) such as 5 to 12 m2/g can be obtained, as well as spinels with low specific surface areas such as 0.1 to 4 m2/g.
By selecting the specific surface area it is possible to influ-10 ence essential application parameters such as dispersibility, bulk density, packing density in the electrode and the stability of the spinel, in particular against chemical decomposition.
Such products can advantageously be obtained by means of an atom-ic ratio of lithium to manganese of from 0.5:2 to 1.6:2, prefer-ably from 0.8:2 to 1.3:2, in particular from 0.9:2 to 1.12:2, and usually have a capacitance of from 100 to 140 mAh/g.
For the preparation of the cathode material, the spinels are pro-20 cessed in a manner known per se.
In electrochemical cells, this cathode material can be used in a manner known per se opposite an anode which takes up lithium cat-ions.
Suitable electrolytes are known to be organic compounds, prefer-ably esters, such as ethylene carbonate and propylene carbonate, or mixtures of such compounds.
30 Such electrochemical cells deliver, as a rule, a voltage of from 3.5 to 4.5 V.
The lithium content of the spinels was determined by atomic ab-sorption spectrometry, the total manganese content was determined as MnzP2O7 after oxidation to manganese(IV) and the content of manganese(III/IV) was determined by reaction with hydrochloric acid and measurement of the chlorine gas formed. The axial ratio (length/width) was determined by means of scanning electron micrographs. The electrical capacitance of the spinels was 40 measured in a manner known per se in a cell having button cell geometry, against a lithium anode with LiC104 in propylene carbonate as electrolyte.
216~259 -_ 6 Examples 1-3 Mixtures of a lithium compound and a manganese compound were reacted with a supply of 200 l/hour of air in a rotating tube which had an internal diameter of 55 mm and a length of 700 mm, heated to 675 C, and which was provided with a static transport screw with webs for thorough mixing of the reaction mixture. The rotary speed of the tube was controlled so that the residence time of the reaction mixture in the heated zone was 2 hours.
The details of these experiments and their results are shown in the table below.
The spinels had a capacitance of 100-110 mAh/g.
The elongated spinels had an axial ratio (length/width) of from 3:1 to 10:1.
Examples 4-15 70 g of mixtures of a lithium compound and a manganese compound were reacted in a 250 ml rotating flask with a supply of 50 l/hour of air. The residence time of the reaction mixture was 2 hours.
The details of these experiments and their results are shown in the table below.
The spinels had a capacitance of 100-110 mAh/g.
Comparative example A mixture of lithium carbonate and manganese carbonate was heated in a crucible for 2 hours at 675 C under air.
A spinel suitable for the preparation of cathode material was not obtained.
The details of this experiment and its result are shown in the ~0 table below.
Table Starting materials Reaction Spinels Li Mn Li/Mn T Li Mn-III Mn-IV Morphology compound compound atom/atom C % by wt. % by wt. % by wt.
Ex. 1 carbonate carbonate 1.10:2 675 4.0 27.0 32.0 isometric Ex. 2 carbonate oxalate1.08:2 675 4.0 27.1 32.2 elongated Ex. 3 oxalate oxalate 1.10:2 675 4.1 25.0 33.6 elongated Ex. 4 carbonate carbonate 1.00:2 650 3.6 26.6 33.8 isometric Ex. 5 carbonate carbonate 1.00:2 675 3.5 34.8 25.2 isometric Ex. 6 carbonate carbonate 1.00:2 700 3.5 36.7 23.8 isometric Ex. 7 carbonate carbonate 1.04:2 650 3.7 30.5 29.1 isometric Ex. 8 carbonate carbonate 1.04:2 675 3.7 31.0 28.7 isometric Ex. 9 carbonate carbonate 1.04:2 700 3.7 32.1 27.7 isometric ~7 Ex. 10 carbonate carbonate 1.08:2 650 3.8 28.3 30.8 isometric Ex. 11 carbonate carbonate 1.08:2 675 3.7 28.8 30.6 isometric r~
Ex. 12 carbonate carbonate 1.08:2 700 3.8 31.0 28.9 isometric CJQ
Ex. 13 carbonate carbonate 1.10:2 650 3.8 28.2 31.3 isometric Ex. 14 carbonate carbonate 1.10:2 675 4.0 28.4 30.7 isometric Ex. 15 carbonate carbonate 1.10:2 700 3.9 30.1 29.3 isometric Comp. carbonate carbonate 1.08:2 675 No spinel suitable as cathode material was Example formed
Claims (15)
1. A process for the preparation of a lithium- and manga-nese(III/IV)-containing spinel by reacting stoichiometric amounts of a lithium compound, of a manganese compound and, if required, of a further metal compound at from 200 to 800°C
under conditions under which the manganese assumes an average oxidation state of from 3.5 to 4.0, which comprises carrying out the reaction with mixing of the reactants.
under conditions under which the manganese assumes an average oxidation state of from 3.5 to 4.0, which comprises carrying out the reaction with mixing of the reactants.
2. A process as claimed in claim 1, wherein the reaction is car-ried out in a rotary tubular furnace.
3. A process as claimed in claim 1 or 2, which is used for the preparation of a spinel of the formula I
Lix (Mnn)2 Ay Oz I
where x is from 0.5 to 1.6, n is the average oxidation state of the manganese in the range from 3.5 to 4.0, A is one equivalent of a metal cation, y is from 0 to 0.4 and z is the number of oxygen equivalents determined by the amount of the other components.
Lix (Mnn)2 Ay Oz I
where x is from 0.5 to 1.6, n is the average oxidation state of the manganese in the range from 3.5 to 4.0, A is one equivalent of a metal cation, y is from 0 to 0.4 and z is the number of oxygen equivalents determined by the amount of the other components.
4. A process as claimed in any of claims 1 to 3, wherein the manganese is used in the form of manganese(II) oxalate and the reaction is carried out under an oxygen-containing atmosphere.
5. A process as claimed in any of claims 1 to 4, wherein the lithium is used in the form of lithium carbonate.
6. A process as claimed in any of the claims 1 to 3, which is used for the preparation of a spinel with a specific surface area of from 0.1 to 4 m2/g, wherein the lithium is used in the form of lithium carbonate or lithium acetate and the man-ganese in the form of manganese carbonate.
7. A lithium- and manganese(III/IV)-containing spinel, obtain-able by a process as claimed in claim 4.
8. A lithium- and manganese(III/IV)-containing spinel, obtain-able by a process as claimed in claim 5.
9. A lithium- and manganese(III/IV)-containing spinel, obtain-able by a process as claimed in claim 6.
10. Use of a lithium- and manganese(III/IV)-containing spinel as claimed in claim 4 as cathode material for electrochemical cells.
11. Use of a lithium- and manganese(III/IV)-containing spinel as claimed in claim 5 as cathode material for electrochemical cells.
12. Use of a lithium- and manganese(III/IV)-containing spinel as claimed in claim 6 as cathode material for electrochemical cells.
13. An electrochemical cell containing, as cathode material, a lithium- and manganese(III/IV)-containing spinel as claimed in claim 4.
14. An electrochemical cell containing, as cathode material, a lithium- and manganese(III/IV)-containing spinel as claimed in claim 5.
15. An electrochemical cell containing, as cathode material, a lithium- and manganese(III/IV)-containing spinel as claimed in claim 6.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEP4444705.1 | 1994-12-15 | ||
DE4444705 | 1994-12-15 | ||
DE19520874.9 | 1995-06-08 | ||
DE19520874A DE19520874A1 (en) | 1994-12-15 | 1995-06-08 | Spinels containing lithium and manganese (III / IV) |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2165259A1 true CA2165259A1 (en) | 1996-06-16 |
Family
ID=25942878
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002165259A Abandoned CA2165259A1 (en) | 1994-12-15 | 1995-12-14 | Lithium- and manganese(iii/iv)-containing spinels |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0717455A1 (en) |
JP (1) | JPH08239221A (en) |
KR (1) | KR960027013A (en) |
CN (1) | CN1143610A (en) |
CA (1) | CA2165259A1 (en) |
DE (1) | DE19520874A1 (en) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6420069B2 (en) | 1996-07-22 | 2002-07-16 | Japan Storage Bottery Co., Ltd | Positive electrode for lithium battery |
EP0914683B1 (en) * | 1996-07-22 | 2003-01-29 | Japan Storage Battery Co., Ltd. | Positive electrode for lithium battery |
TW434187B (en) * | 1997-05-07 | 2001-05-16 | Fuji Chem Ind Co Ltd | A process for preparing a spinel type of lithium manganese complex oxide |
US6277521B1 (en) | 1997-05-15 | 2001-08-21 | Fmc Corporation | Lithium metal oxide containing multiple dopants and method of preparing same |
CA2240805C (en) | 1997-06-19 | 2005-07-26 | Tosoh Corporation | Spinel-type lithium-manganese oxide containing heteroelements, preparation process and use thereof |
DE19815611A1 (en) * | 1998-04-07 | 1999-10-14 | Riedel De Haen Gmbh | Process for the production of lithium metal oxides |
US6267943B1 (en) | 1998-10-15 | 2001-07-31 | Fmc Corporation | Lithium manganese oxide spinel compound and method of preparing same |
WO2000029331A1 (en) | 1998-11-13 | 2000-05-25 | Fmc Corporation | Layered lithium metal oxides free of localized cubic spinel-like structural phases and methods of making same |
CN1243664C (en) | 1999-12-10 | 2006-03-01 | Fmc公司 | Lithium cobalt oxides and methods of making same |
JP2002134110A (en) * | 2000-10-23 | 2002-05-10 | Sony Corp | Method of producing positive electrode active material and method of producing nonaqueous electrolyte battery |
TW201136837A (en) * | 2010-01-29 | 2011-11-01 | Basf Se | Producing oxidic compounds |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4921689A (en) * | 1988-06-24 | 1990-05-01 | Duracell Inc. | Process for producing beta manganese dioxide |
CA2022898C (en) * | 1989-08-15 | 1995-06-20 | Nobuhiro Furukawa | Non-aqueous secondary cell |
JP2851671B2 (en) * | 1990-02-24 | 1999-01-27 | 工業技術院長 | Method for producing lithium adsorbent |
US5180574A (en) * | 1990-07-23 | 1993-01-19 | Moli Energy (1990) Limited | Hydrides of lithiated nickel dioxide and secondary cells prepared therefrom |
ZA936168B (en) * | 1992-08-28 | 1994-03-22 | Technology Finance Corp | Electrochemical cell |
JPH06171947A (en) * | 1992-12-11 | 1994-06-21 | Mitsui Toatsu Chem Inc | Production of lithium vanadium oxide |
-
1995
- 1995-06-08 DE DE19520874A patent/DE19520874A1/en not_active Withdrawn
- 1995-12-07 EP EP95119263A patent/EP0717455A1/en not_active Withdrawn
- 1995-12-14 CA CA002165259A patent/CA2165259A1/en not_active Abandoned
- 1995-12-15 CN CN95113119A patent/CN1143610A/en active Pending
- 1995-12-15 JP JP7327194A patent/JPH08239221A/en active Pending
- 1995-12-15 KR KR1019950050347A patent/KR960027013A/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
KR960027013A (en) | 1996-07-22 |
EP0717455A1 (en) | 1996-06-19 |
DE19520874A1 (en) | 1996-06-20 |
JPH08239221A (en) | 1996-09-17 |
CN1143610A (en) | 1997-02-26 |
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