Tdk Corporation

Akinobu Nojima

Atsushi Sano

Masaki Sobu

Yasuhiro Ikeda

Tomohiko Kato

Keitaro Otsuki

Hideaki Seki

Takashi Sasaki

Akiji Higuchi

Tomohiko Hasegawa

Hirofumi Kakuta

Shin Fujita

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

In this non-aqueous electrolyte secondary battery, a positive terminal and a negative terminal extend in a first direction, protrude from a laminated cell stack, and are provided so that a center line is interposed therebetween, the center line passing through a midpoint of both ends of the laminated cell stack in a second direction orthogonal to the first direction and extending in the first direction when the laminated cell stack is seen in plan view, and a first terminal with higher heat dissipation efficiency among the positive terminal and the negative terminal is provided in a location closer to the center line than a location of a second terminal with lower heat dissipation efficiency among the positive terminal and the negative terminal.

Non-aqueous electrolyte secondary battery

A negative electrode active material with sufficiently high discharge capacity at a high rate, and a negative electrode and a lithium ion secondary battery using the negative electrode active material. A negative electrode active material according to the invention includes a negative electrode active material particle containing silicon and silicon oxide, wherein a surface layer part of the negative electrode active material particle is a layer with lower density than a core part of the negative electrode active material particle. With such a structure of the negative electrode active material, the sufficiently high discharge capacity at a high rate can be obtained.

Negative electrode active material, and negative electrode and lithium ion secondary battery using the negative electrode active material

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 negative electrode active material is provided for a lithium ion secondary battery having high initial charging/discharging efficiency. The negative electrode active material containing silicon and silicon oxide has two phases with different compositions therein. One of the two phases has a lower silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of primary particle of the negative electrode active material. Use of the negative electrode active material enables a sufficient increase in initial charging/discharging efficiency.

A positive electrode active material for a lithium ion secondary battery contains: a first compound represented by chemical formula Li(NiMa)O(0.95&#x2264;x&#x2264;1.05, 0.70&#x2264;y&#x2264;0.95, where Ma is at least one element selected from Co, Mn, V, Ti, Fe, Zr, Nb, Mo, Al, and W); and a second compound represented by chemical formula LiVOPO. W&#x3e;5.0&#xb0; C., where W is a full width at half maximum of an exothermic peak obtained between 150&#xb0; C. and 260&#xb0; C. by differential scanning calorimetry (DSC) performed on a mixture of the first compound and the second compound under a condition of 5&#xb0; C./min.

Positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery positive electrode and lithium ion secondary battery using the same

Provided are a negative electrode active material for a lithium ion secondary battery, which has sufficiently high discharge capacity at a high rate. The negative electrode active material containing silicon and silicon oxide includes primary particles having two phases of different compositions therein. One of the two phases has a higher silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of the primary particle. Use of the negative electrode active material enables a sufficient increase in discharge capacity at a high rate.

To provide an active material with high capacity, high initial charge-discharge efficiency, and high average discharge voltage. An active material according to the present invention includes a first active material and a second active material, wherein the ratio (&#x3b4;) of the second active material (B) to the total amount by mole of the first active material (A) and the second active material (B) satisfies 0.4 mol %&#x2266;&#x3b4;&#x2266;18 mol % [where &#x3b4;=(B/(A+B))&#xd7;100].

Active material, electrode using same, and lithium ion secondary battery

An active material having high capacity and excellent charging/discharging cycle durability at high potential is provided. The active material has a layered structure and is represented by the following composition formula (1):LiNiCoMnMOFP&#x2003;&#x2003;(1)wherein the element M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and 1.9&#x2266;(a+b+c+d+y)&#x2266;2.1, 1.0&#x2266;y&#x2266;1.3, 0&#x3c;a&#x2266;0.3, 0&#x2266;b&#x2266;0.25, 0.3&#x2266;c&#x2266;0.7, 0&#x2266;d&#x2266;0.1, 0.07&#x2266;z1&#x2266;0.15, 0.01&#x2266;z2&#x2266;0.1, and 1.9&#x2266;(x+z1)&#x2266;2.1 are satisfied.

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Tokyo, Japan

Akinobu Nojima