Tdk Corporation

Keitaro Otsuki

Atsushi Sano

Akiji Higuchi

Takeshi Takahashi

Tomohiko Kato

Yosuke Miyaki

Masahiro Saegusa

Tetsu Sato

Kouji Tokita

Keiichi Fukuda

Tohru Inoue

Akinobu Nojima

Hisashi Suzuki

Masahiro Oishi

Tomohiko Hasegawa

Masayoshi Hirano

A negative electrode includes a current collector and a negative electrode active material layer that is provided on the current collector and includes a negative electrode active material. The negative electrode active material includes a carbon material, and a surface of the negative electrode active material layer has a spectral reflectance Ra in a range of 7.0&#x2264;Ra&#x2264;10.8% at a wavelength of 550 nm.

Negative electrode active material layer with controlled reflectance and lithium ion secondary battery

An electrode and a lithium ion secondary battery having excellent cycle characteristics in a high temperature environment are provided. An electrode includes: an active material layer including an active material, a conductive assistant, and a binder, wherein the active material contains active material particles containing a lithium transition metal oxide as a main component, and the active material particles each include a core part having a space group of R-3m and a covering part having a space group of Fm-3m configured to cover at least part of an outer circumferential portion of the core part.

Electrode and lithium ion secondary battery

A positive electrode includes a positive electrode current collector, and a positive electrode active material layer that is provided on the positive electrode current collector and that includes a positive electrode active material, a conductive auxiliary agent, and a binder. A surface of the positive electrode active material layer has a reflectance Rc in a range of 2.0&#x2264;Rc&#x2264;12.0% at a wavelength of 550 nm. A lithium ion secondary battery includes: the positive electrode; a negative electrode including a negative electrode current collector and a negative electrode active material layer that is provided on the negative electrode current collector and that includes a negative electrode active material; a separator; and a nonaqueous electrolyte solution. A surface of the negative electrode active material layer has a reflectance Ra in a range of 7.5&#x2264;Ra&#x2264;16.0% at a wavelength of 550 nm.

Positive electrode and lithium ion secondary battery

A negative electrode includes a negative electrode current collector and a negative electrode active material layer that is provided on the negative electrode current collector and includes a negative electrode active material. The negative electrode active material includes a carbon material, and a surface of the negative electrode active material layer has a reflectance Ra in a range of 7.0&#x2264;Ra&#x2264;14.8% at a wavelength of 550 nm. A lithium ion secondary battery includes the negative electrode, a positive electrode, a separator, and a nonaqueous electrolyte solution. The nonaqueous electrolyte solution includes a nonaqueous solvent and an electrolyte, the nonaqueous solvent contains ethylene carbonate, and the ethylene carbonate is contained in a range of 10 to 30 vol. % in the entire nonaqueous solvent.

A method for manufacturing an active material, capable of improving the discharge capacity of a lithium ion secondary battery is provided. The method for manufacturing an active material according to the present invention includes a first step of heating a mixture solution including a lithium source, a phosphate source, a vanadium source, and water under pressure to generate a precursor in the mixture solution, and adjusting the pH of the mixture solution including the precursor to be 6 to 8; and a second step of heating the precursor at 425 to 650&#xb0; C. after the first step to generate an active material.

Active material, method for manufacturing active material, electrode, lithium ion secondary battery, and method for manufacturing lithium ion secondary battery

A lithium ion secondary battery includes: a positive electrode including a positive electrode active material layer; a negative electrode; and an electrolyte. The positive electrode active material layer contains Li(M)(PO)(M=VO or V, 0.9&#x2264;a&#x2264;3.3, 0.9&#x2264;b&#x2264;2.2, 0.9&#x2264;c&#x2264;3.3) as a first positive electrode active material, and additionally contains a fluorine compound of 1 to 300 ppm in terms of fluorine with respect to a weight of the positive electrode active material layer.

Lithium ion secondary battery

The present invention provides an active material which can increase the discharge capacity of a lithium-ion secondary battery as compared with the case using conventional LiMnPOas a positive electrode active material. The active material in accordance with the present invention contains a crystallite of LiMnPO, the crystallite having a size of 20 to 93 nm in a direction perpendicular to a (060) plane thereof.

Active material, method of manufacturing active material, and lithium-ion secondary battery

An active material capable of improving the discharge capacity of a lithium ion secondary battery is provided. The active material of the present invention includes LiVOPOand one or more metal elements selected from the group consisting of Al, Nb, Ag, Mg, Mn, Fe, Zr, Na, K, B, Cr, Co, Ni, Cu, Zn, Si, Be, Ti, and Mo.

Active material, method for manufacturing active material, electrode, and lithium ion secondary battery

The lithium-ion secondary battery includes a positive electrode containing an active material made of a compound including lithium and a transition metal; an electrolyte containing 5 to 30 ppm of hydrofluoric acid; and a negative electrode containing 1 to 100 ppm of vanadium.

Lithium-ion secondary battery with a negative electrode containing vanadium

A nonaqueous electrolyte for a lithium-ion secondary battery containing 0.1 ppm to 20 ppm of vanadium in terms of vanadium ions, and containing cyclic carbonate and chain carbonate is used.

Nonaqueous electrolyte for lithium-ion secondary battery containing vanadium and lithium-ion secondary battery containing same

An active material that can achieve sufficient discharge capacity at high discharging rate, an electrode including the active material, and a lithium ion secondary battery including the electrode, and a method for manufacturing the active material are provided. The active material includes a LiVOPOpowder, a first carbon powder, and a second carbon powder. A relational expression of 0.05&#x2266;A1/A2&#x2266;0.5 is satisfied, where A1 represents the ratio of the G band peak height observed around 1580 cmin Raman spectrum of the first carbon powder to the 2D band peak height observed around 2700 cmin the Raman spectrum of the first carbon powder, and A2 represents the ratio of the G band peak height observed around 1580 cmin Raman spectrum of the second carbon powder to the 2D band peak height observed around 2700 cmin the Raman spectrum of the second carbon powder.

Active material, electrode, lithium ion secondary battery, and method for manufacturing active material

A positive electrode material for a lithium ion secondary battery contains a first compound represented by LiV(PO)and one or more second compounds selected from vanadium oxide and lithium vanadium phosphate.

Positive electrode material for lithium ion secondary battery, positive electrode for lithium ion secondary battery, and lithium ion secondary battery

To provide an active material from which a sufficient discharge capacity is obtained, an electrode containing the active material, a lithium secondary battery including the electrode, and a method for making an active material. A method for making an active material includes a temperature elevation step of heating a mixture containing a lithium source, a pentavalent vanadium source, a phosphoric acid source, water, and a reductant in a hermetically sealed container at a temperature elevation rate T1 from 25&#xb0; C. to 110&#xb0; C. and then at a temperature elevation rate T2 from 110&#xb0; C. to a designated temperature of 200&#xb0; C. or more, in which T1&#x3e;T2; T1=0.5 to 10&#xb0; C./min; and T2=0.1 to 2.2&#xb0; C./min.

Active material, electrode containing the active material, lithium secondary battery including the electrode, and method for making active material

An active material contains a triclinic LiVOPOcrystal particle, while the crystal particle has a spherical form and an average particle size of 20 to 200 nm.

Active material and positive electrode and lithium-ion second battery using same

A method for manufacturing an active material containing a triclinic LiVOPOcrystal particle that has a spherical form and an average particle size of 20 to 200 nm. The method includes a step of manufacturing the crystal particle by hydrothermal synthesis.

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Tokyo, Japan

Keitaro Otsuki