Classifications

• • 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
  • H01M4/04—Processes of manufacture in general
  • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• • 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
  • C01G45/1228—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof of the type [MnO2]n-, e.g. LiMnO2, Li[MxMn1-x]O2
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G53/00—Compounds of nickel
  • C01G53/40—Nickelates
  • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
  • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G53/00—Compounds of nickel
  • C01G53/40—Nickelates
  • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
  • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
  • C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• • 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
• • 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
  • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
  • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/50—Solid solutions
  • C01P2002/52—Solid solutions containing elements as dopants
• • 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
• • 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
• • 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
  • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
  • H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
  • H01M2004/8689—Positive electrodes
• • 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
• • 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
  • Y02E60/30—Hydrogen technology
  • Y02E60/50—Fuel cells

Definitions

• the invention relates to a positive active electrode material for use in rechargeable lithium ion batteries, to a lithium secondary cell having the electrode material according to the invention, and to a method for the production of the latter.
• Lithium batteries have very large volume- and weight-specific energy densities (respectively about 300 Wh/1 and 120 Wh/kg at present) , have high cell voltages (about 4 V) and relatively low self-discharge rates.
• Batteries with metallic lithium are generally less suitable since the cycle life is generally insufficient, and there are furthermore safety questions regarding the use of metallic lithium.
• the positive electrode of a lithium battery may consist of LiCo0 2 , LiNi0 2 or Li n 2 0 4 , the negative electrode of graphite or coke and the separator of a porous plastic.
• the lithium ions are reversibly absorbed and released at these electrodes .
• the ions migrate from the positive electrode to the negative electrode during the charging process, and then in the opposite direction during discharge.
• LiCo0 2 is almost exclusively used at present as the active positive electrode material in lithium ion batteries. Yet there is a need for alternative materials which can be produced from starting materials that are less expensive as well as less toxic, while having the same or even a better performance, particularly for large batteries.
• LiCo0 2 is the cathode material of " choice for rechargeable lithium ion batteries. It has a layer structure with the space group R-3m, presents a good initial capacity and a good cycle stability. But LiCo0 2 is relatively expensive, and there are furthermore safety questions regarding the use of LiCo0 2 in large batteries.
• LiCo0 2 LiCo0 2
• LiNi0 2 may be used as an alternative material. It has a layer structure with the space group
• LiCo0 2 is relatively inexpensive and has a higher capacity.
• the production of LiNi0 2 on an industrial scale entails difficulties, however, and there are furthermore safety questions.
• LiMn 2 0 4 is a cathode material.
• LiMn 2 0 4 has the spinel form, is cheaper than LiCo0 2 and also safer.
• the disadvantage of using LiMn 2 Q 4 is the low capacity, however, and there are also stability problems at elevated temperatures .
• Li (Ni,Mn, Co) 0 2 materials are used. These materials each have layer structures and crystallise in the space group R-3m. The use of Ni and Mn leads to a cost reduction and increases safety, which is attributable to the involvement of Mn. Such materials have a high initial capacity, but the disadvantage is the insufficient cycle stability.
• cathode materials are extremely promising and are currently at the focus of interest in research and development worldwide. In our experience, these materials present high initial capacities but only a low cycle stability, especially materials which have a low Co content.
• WO 01/41238 describes an electrode material for positive electrodes of rechargeable batteries, which is based on a lithium-transition metal mixed oxide with at least two transition metals (for example nickel and/or manganese) , has a layer structure and is doped, for example, with aluminium and/or boron.
• This electrode material is distinguished by a high cycle stability but is nevertheless inexpensive to produce. It has proved particularly advantageous for the electrode material to have the composition LiMno.5Nio.4Alo. 1 O2. This electrode material is stable with respect to the specific charge (Ah/kg) over 200 cycles as a positive electrode.
• EP 1 130 665 Al describes an active material for a positive electrode for a secondary battery with a non-aqueous electrolyte, the active material comprising a manganese composite oxide containing lithium with a layered crystal structure, which is represented by the general formula Li ⁇ _ x Mn ⁇ - y M y ⁇ 2- ⁇ - With this electrode material, an improved cycle stability can be observed when M is selected from Co, Ni, Fe, Al, Ga, In, V, Nb, Ta, Ti, Zr, Ce or Cr .
• EP 944 125 Al describes an improved cycle stability for Li a C ⁇ M c i ⁇ -- c 0 2 (0.02 ⁇ b+c ⁇ 0.5) compared with the unsubstituted compound, when M is selected from B, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Ga, Ge, Y, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In and Sn.
• This object is achieved by mixing together a mixture of a lithium compound, a nickel compound, manganese oxide, cobalt oxide and niobium and/or tantalum oxide in a suitable ratio, subjecting this mixture to a heat treatment and subsequently comminuting it and grinding it to a powder
• Lithium carbonate or lithium hydroxide may be used as the lithium compound here.
• Nickel carbonate or nickel hydroxide may be used as the nickel compound here.
• the lithium complex oxides according to the invention are produced by solid-state methods. Commercial oxides, hydroxides and carbonates of the corresponding elements are used. Lithium carbonate, nickel carbonate, manganese oxide, cobalt oxide and a compound of the dopant (boric acid, aluminium hydroxide, magnesium hydroxide, niobium (V) oxide or tantalum (V) oxide) are mixed together in a suitable ratio.
• suitable ratio is intended to mean a ratio which is used in order to produce the materials according to the invention .
• the heat treatment prefferably carried out at a temperature of 900°C - 1000°C.
• the heat treatment is preferably carried out in an oxidising atmosphere, i.e. in an air atmosphere or in an air atmosphere which has been supplemented with oxygen.
• the time period for this is between 4 and 20 h. It is preferable for the heat treatment to be carried out for a period of 8 - 12 h.
• the mixture is subsequently ground to a powder with a defined particle size.
• a grinding device which is known to the person skilled in the art, may be used for this.
• a ball mill may be used for the grinding.
• the powder obtained in this way has a particle size of d90 ⁇ 20 ⁇ m.
• the phase identity and the purity of the products was checked by using X-ray diffractometry (XRD) .
• a lithium secondary cell having a positive electrode, which reversibly absorbs and releases lithium ions, a negative electrode which contains lithium or a lithium compound, and a non-aqueous electrolyte, which is characterised in that the positive active electrode material has the general formula
• Compound 1 is the undoped starting compound, and is used as a comparison compound.
• Compounds 3a, 3b, 4a, 4b, 5a, 5b, 6a and 6b contain 1 or 5 mol% of Al, Mg, Nb and Ta .
• B only the 1% doped material could be produced (compound 2a) .
• Li 3 B0 3 was observed by means of X-ray diffraction (XRD) as a secondary phase.
• X-ray diffraction (XRD) confirmed the phase purity.
• electrodes were produced by using a standard method comprising the steps of mixing the oxides with a binder system, carbon black and graphite and an organic solvent, spreading the mixture over an aluminium foil and drying. A round electrode was punched out. An electrochemical cell was set up with this electrode, a separator, an electrolyte and a lithium foil which functions as the other electrode.
• the cell was subsequently operated between 3.0 and 4.4 V vs. Li/Li + .
• 30 cycles were generally carried out by using the following programme: a specific current of 10 mA/g was used for cycles 1-2 or 1-3, and 30 mA/g were applied for the next cycles. A current of 75 mA/g was used between cycles 21-24 or 21-25.
• Compounds 1, 2a, 3a, 3b, 4a, 4b, 5a, 5b, 6a were electrochemically tested by using the method as described above.
• Table 1 shows the discharge capacities measured in the 4 th and 30 th cycles.
• the undoped material 1 starts at 146 mAh/g and presents only a moderate cycle stability with a loss of 9 mAh/g by the 30 th cycle.
• the doped compounds 2a, 3a, 4a, 5a and 6a have about the same initial values in the 4 th cycle.
• the doping with 1% B shows a good positive effect on the cycle stability, whereas the doping with 1% Al shows virtually no effect and the doping with 1% Mg actually shows a negative effect.
• the doping with 1% Nb increases the cycle stability considerably: a loss of only 2 mAh/g is observed from the 4 th cycle to the 30 th cycle
• the effect of doping with 1% Ta is not as great as that of Nb, but this compound still performs better than the comparative examples.
• the doping with 5% Al and Mg impairs the electrochemical performance considerably.
• Table 1 shows the discharge capacities after the 4 th and 30 th cycles
• Table 1 Discharge capacities after the 4 and 30th cycles
• Figure 1 shows the cycle curves for the undoped compound and the 1% doped materials 2a, 3a, 4a and 5a.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Battery Electrode And Active Subsutance (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34832870

Family Applications (1)

Country Status (2)

Cited By (8)

Citations (5)

Family Cites Families (2)

• 2004
  • 2004-02-20 DE DE102004008397A patent/DE102004008397B4/de not_active Expired - Fee Related
• 2005
  • 2005-01-21 WO PCT/EP2005/000600 patent/WO2005081338A1/en active Application Filing

Patent Citations (5)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events