Abstract: The present invention provides a positive electrode active material for lithium ion batteries having excellent rate performance. The positive electrode active material for lithium ion batteries having a layered structure is represented by composition formula: Lix(NiyM1-y)Oz, wherein M is Mn and Co, x is 0.9 to 1.2, y is 0.6 to 0.9, z is 1.8 to 2.4. D2/D1 is 1.065 or less, D1 being defined as the density of the positive electrode active material when powder of the positive electrode active material is pressed under the pressure of 100 MPa, and D2 being defined as the density of the positive electrode active material when powder of the positive electrode active material is pressed under the pressure of 300 MPa.

Abstract: 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(NiyM1-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 ?m or less in terms of the volume ratio after pressing at 100 MPa.

Abstract: Disclosed is a positive electrode active material that provides an improved capacity density. Specifically disclosed is a positive electrode active material for a lithium ion battery with a layered structure represented by Lix(NiyM1-y)Oz (wherein M represents at least one element selected from a group consisting of Mn, Co, Mg, Al, Ti, Cr, Fe, Cu, and Zr; x is in the range from 0.9 to 1.2; y is in the range from 0.3 to 0.95; and z is in the range from 1.8 to 2.4), wherein, when a value obtained by dividing an average of peak intensities observed between 1420 and 1450 cm?1 and between 1470 and 1500 cm?1 by the maximum intensity of a peak appearing between 520 and 620 cm?1 in an infrared absorption spectrum obtained by FT-IR is represented by A, A satisfies the following relational formula: 0.20y?0.05?A?0.53y?0.06.

Abstract: 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 ?m or less in terms of the volume ratio after pressing at 100 MPa.

Abstract: The present invention provides a positive electrode active material for lithium ion battery which attains a lithium ion battery having high safety. The positive electrode active material for lithium ion battery has a layer structure represented by the compositional formula: Lix(NiyM1-y)Oz (wherein M represents Mn and Co, x denotes a number of 0.9 to 1.2, y denotes a number of 0.6 to 0.65, and z denotes a number of 1.8 to 2.4). When a lithium ion battery using a positive electrode mix produced by the positive electrode active material, a binder, and a conductive material in a ratio by weight of 91%, 4.2%, and 4.8%, respectively, is charged to 4.3V, and then an electrolytic solution prepared by dissolving 1 M—LiPF6 in a mixture solvent of ethylene carbonate (EC)-dimethyl carbonate (DMC) (volume ratio 1:1) is used based on 1.0 mg of the positive electrode mix to measure the obtained lithium ion battery by differential scanning calorimetry (DSC) performed at a temperature rise rate of 5° C.

Abstract: The present invention provides a positive electrode active material for lithium ion battery which attains a lithium ion battery having high safety. The positive electrode active material for lithium ion battery which has a layer structure represented by the compositional formula: Lix(NiyM1-y)Oz (wherein M represents Mn and Co, x denotes a number of 0.9 to 1.2, y denotes a number of 0.8±0.025, and z denotes a number of 1.8 to 2.4). After a lithium ion battery using a positive electrode mix produced by the positive electrode active material, a binder, and a conductive material in a ratio by weight of 91%, 4.2%, and 4.8%, respectively, is charged to 4.3 V, an accumulated calorific value in a temperature range from 170 to 300° C., which is obtained by differential scanning calorimetry (DSC) performed at a temperature rise rate of 5° C./min using an electrolytic solution prepared by dissolving 1 M-LiPF6 in a mixture solvent of ethylene carbonate (EC)-dimethyl carbonate (DMC) (volume ratio 1:1) based on 1.

Abstract: The present invention provides a positive electrode active material for lithium ion battery which attains a lithium ion battery having high safety. The positive electrode active material for lithium ion battery has a layer structure represented by the compositional formula: Lix(NiyM1-y)Oz (wherein M represents Mn and Co, x denotes a number of 0.9 to 1.2, y denotes a number of 0.8±0.025, and z denotes a number of 1.8 to 2.4). When a lithium ion battery using a positive electrode mix produced by the positive electrode active material, a binder, and a conductive material in a ratio by weight of 91%, 4.2%, and 4.8%, respectively, is charged to 4.3V, and then an electrolytic solution prepared by dissolving 1 M-LiPF6 in a mixture solvent of ethylene carbonate (EC)-dimethyl carbonate (DMC) (volume ratio 1:1) is used based on 1.0 mg of the positive electrode mix to measure the obtained lithium ion battery by differential scanning calorimetry (DSC) performed at a temperature rise rate of 5° C.

Abstract: The present invention provides a positive electrode active material for lithium ion battery which attains a lithium ion battery having high safety. The positive electrode active material has a layer structure for a lithium ion battery, in which the positive electrode active material is represented by the following composition formula: Lix(NiyM1-y)Oz (wherein M represents Mn and Co, x is 0.9 to 1.2, y is 0.8±0.025, and z is 1.8 to 2.4), and ?T=T41?T44, that is a difference between a first exothermic peak temperature T44 (° C.) of a first lithium ion battery and a first exothermic peak temperature T41 (° C.) of a second lithium ion battery, both are obtained by a differential scanning calorimetry (DSC) carried out at temperature increase rate of 5° C./min, when a lithium ion battery using a positive electrode mixture prepared with the positive electrode active material, a binder, and a conductive material in weight ratio of 91%, 4.2%, and 4.8%, respectively is charged to 4.

Abstract: The present invention provides a positive electrode active material for lithium ion battery which attains a lithium ion battery having high safety. The positive electrode active material has a layer structure for a lithium ion battery, in which the positive electrode active material is represented by the following composition formula: Lix(NiyM1-y)Oz (wherein M represents Mn and Co, x is from 0.9 to 1.2, y is 0.8±0.025, and z is from 1.8 to 2.4), and 66 T=T10-T5, that is a difference between a first exothermic peak temperature T5 (° C.) obtained by a differential scanning calorimetry (DSC) carried out at temperature increase rate of 5° C./min and a first exothermic peak temperature T10 (° C.) obtained by a differential scanning calorimetry (DSC) carried out at temperature increase rate of 10° C./min, satisfies the condition of ?T?10 (° C.

Abstract: The present invention provides a positive electrode active material for lithium ion batteries having excellent rate performance. The positive electrode active material for lithium ion batteries having a layered structure is represented by composition formula: Lix(NiyM1-y)Oz, wherein M is Mn and Co, x is 0.9 to 1.2, y is 0.6 to 0.9, z is 1.8 to 2.4. D2/D1 is 1.065 or less, D1 being defined as the density of the positive electrode active material when powder of the positive electrode active material is pressed under the pressure of 100 MPa, and D2 being defined as the density of the positive electrode active material when powder of the positive electrode active material is pressed under the pressure of 300 MPa.

Abstract: Disclosed is a positive electrode active material that provides an improved capacity density. Specifically disclosed is a positive electrode active material for a lithium ion battery with a layered structure represented by Lix(NiyM1-y)Oz (wherein M represents at least one element selected from a group consisting of Mn, Co, Mg, Al, Ti, Cr, Fe, Cu, and Zr; x is in the range from 0.9 to 1.2; y is in the range from 0.3 to 0.95; and z is in the range from 1.8 to 2.4), wherein, when a value obtained by dividing an average of peak intensities observed between 1420 and 1450 cm?1 and between 1470 and 1500 cm?1 by the maximum intensity of a peak appearing between 520 and 620 cm?1 in an infrared absorption spectrum obtained by FT-IR is represented by A, A satisfies the following relational formula: 0.20y?0.05?A?0.53y?0.06.