Positive Electrode Active Material For Lithium-Ion Battery, Positive Electrode For Lithium-Ion Battery, And Lithium-Ion Battery

• Main Author: SATOH HIROHITO
• Format: Patent
• Language: English
• Published: 03.01.2013
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OFSOLID INORGANIC COMPOUNDS; INORGANIC CHEMISTRY; METALLURGY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

The present invention provides a positive electrode active material for lithium ion battery having good rate characteristics. The positive electrode active material for lithium ion battery has a layer structure expressed by a composition formula: Lix(NiyMi1-y)Oz, wherein M represents Mn and Co, x represents 0.9 to 1.2, y represents 0.6 to 0.9, and z represents 1.8 to 2.4. The positive electrode active material has a particle size ratio D50P/D50 of 0.60 or more, wherein D50 is the average secondary particle size of the positive electrode active material powder, and D50P is the average secondary particle size of the positive electrode active material powder after pressing at 100 MPa. The positive electrode active material contains 3% or less particles having a particle size of 0.4 μm or less in terms of the volume ratio after pressing at 100 MPa.