Semiconductor Energy Laboratory Co., Ltd.

Yumiko Yoneda

Takuya Miwa

Ryota Tajima

Yohei Momma

Masaki Yamakaji

Teppei Oguni

Masaaki Hiroki

Yuugo Goto

Teruaki Ochiai

Shunpei Yamazaki

Mayumi Mikami

Tatsuya Ikenuma

Masahiro Takahashi

Kazutaka Kuriki

Minoru Takahashi

Aya Uchida

Ayae Tsuruta

Takahiro Kawakami

Shuhei Yoshitomi

Junya Goto

Satoshi Seo

Tatsuyoshi Takahashi

Hiroshi Kadoma

Yuji Iwaki

Nobuhiro Inoue

Kaori Ogita

Kiyofumi Ogino

Shunsuke Adachi

Rika Yatabe

Tomoya Hirose

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

Positive electrode active material including lithium-containing complex phosphate elliptical particles, power storage device, electronic device, and method for manufacturing: positive electrode active material

A secondary battery with excellent cycle performance is provided. The secondary battery is an all-solid-state battery including a positive electrode current collector layer, a base film, a positive electrode active material layer, a buffer layer, and a solid electrolyte layer. The base film contains titanium nitride. The positive electrode active material layer contains lithium cobalt oxide. The buffer layer contains titanium oxide. The solid electrolyte layer contains a titanium compound. By using titanium oxide for the buffer layer, a side reaction between the positive electrode active material layer and the solid electrolyte layer can be suppressed, and cycle performance can be improved.

Secondary battery and manufacturing method thereof

In the case where a film, which has lower strength than a metal can, is used as an exterior body of a secondary battery, a current collector provided in a region surrounded by the exterior body, an active material layer provided on a surface of the current collector, or the like might be damaged when force is externally applied to the secondary battery. A secondary battery which is resistant to external force in obtained. An opening is provided in a central portion of the secondary battery, and a terminal is formed in the opening. An outer edge of the secondary battery is fixed by thermocompression bonding. In addition, the central portion of the secondary battery is fixed by thermocompression bonding, so that the amount of bending is limited even when the outer edge portion of the secondary battery is bent.

Electronic device including secondary battery

A solid-state secondary battery with high safety is provided. The solid-state secondary battery includes a first film that has a function of releasing and accumulating a lithium ion and is over a negative electrode current collector layer, a second film that has a function of transporting a lithium ion and is over the first film, a third film that has a function of releasing and accumulating a lithium ion and is over the second film, and a positive electrode current collector layer over the third film. The total thickness of the first to third films is the same before and after charging.

Solid-state secondary battery

A positive electrode active material having high capacity and excellent cycle performance is provided. The positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charge and discharge as compared with those of a known positive electrode active material.

Positive electrode active material, method for manufacturing positive electrode active material, and secondary battery

A lithium-ion secondary battery having high capacity and excellent charge and discharge cycle performance is provided. A secondary battery having high capacity is provided. A secondary battery having excellent charge and discharge performance is provided. A secondary battery in which a decrease in capacity is suppressed even at high temperatures is provided. The secondary battery includes a positive electrode, a negative electrode, an electrolyte solution, and an exterior body. The positive electrode includes a positive electrode active material. The positive electrode active material contains lithium, cobalt, oxygen, magnesium, and fluorine. The number of magnesium atoms contained in the positive electrode active material is greater than or equal to 0.001 times and less than or equal to 0.1 times the number of cobalt atoms contained in the positive electrode active material. The positive electrode active material includes a region having a layered rock-salt crystal structure. The electrolyte solution contains an ionic liquid. The exterior body includes a metal layer and a polymer layer stacked over the metal layer. The polymer layer includes a region in contact with the electrolyte solution.

Secondary battery, electronic device, and vehicle

A gel electrolyte and a separator are provided between the positive electrode current collector and the negative electrode current collector. The plurality of positive electrode current collectors and the plurality of negative electrode current collectors are stacked such that surfaces of negative electrodes with which active material layers are not coated or surfaces of positive electrodes with which active material layers are not coated are in contact with each other.

Secondary battery

Use of silicon as a negative electrode active material particle causes a problem of expansion and contraction of the negative electrode active material particle due to charging and discharging. A negative electrode active material particle or a plurality of negative electrode active material particles are bound or fixed using a graphene compound to inhibit expansion and contraction of the negative electrode active material particle due to charging and discharging. In an all-solid-state secondary battery, an interface between a solid electrolyte and a negative electrode or an interface between the solid electrolyte and a positive electrode has the highest resistance. In order to reduce the interface resistance, at least the negative electrode active material particle is surrounded by a graphene compound to increase the conductivity. Alternatively, a positive electrode active material particle is surrounded by a graphene compound to increase the conductivity. Carrier ions, e.g., lithium ions, pass through a graphene compound, and thus the graphene compound does not hinder the transfer of lithium ions between the positive electrode and the negative electrode in charging or discharging.

All-solid-state battery and manufacturing method thereof

An all-solid-state secondary battery having a higher level of safety than a conventional lithium-ion secondary battery using an electrolyte solution, specifically, a thin-film-type solid-state secondary battery, and a manufacturing method thereof are provided. As a solid electrolyte, a mixed material obtained by co-evaporation of SiO and an organic complex of lithium is used. That is, a solid electrolyte layer formed using a mixed material of an inorganic material and an organic material is used in a solid-state secondary battery. The ratio of oxygen to silicon in the solid electrolyte layer is higher than 1 and lower than 2.

Solid-state secondary battery and manufacturing method thereof

To provide graphene oxide that has high dispersibility and is easily reduced. To provide graphene with high electron conductivity. To provide a storage battery electrode including an active material layer with high electric conductivity and a manufacturing method thereof. To provide a storage battery with increased discharge capacity. A method for manufacturing a storage battery electrode that is to be provided includes a step of dispersing graphene oxide into a solution containing alcohol or acid, a step of heating the graphene oxide dispersed into the solution, and a step or reducing the graphene oxide.

Storage battery electrode, manufacturing method thereof, storage battery, electronic device, and graphene

A composite oxide with high diffusion rate of lithium is provided. Alternatively, a lithium-containing complex phosphate with high diffusion rate of lithium is provided. Alternatively, a positive electrode active material with high diffusion rate of lithium is provided. Alternatively, a lithium ion battery with high output is provided. Alternatively, a lithium ion battery that can be manufactured at low cost is provided. A positive electrode active material is formed through a first step of mixing a lithium compound, a phosphorus compound, and water, a second step of adjusting pH by adding a first aqueous solution to a first mixed solution formed in the first step, a third step of mixing an iron compound with a second mixed solution formed in the second step, a fourth step of performing heat treatment under a pressure more than or equal to 0.1 MPa and less than or equal to 2 MPa at a highest temperature more than 100° C. and less than or equal to 119° C. on a third mixed solution formed in the third step with a pH of more than or equal to 3.5 and less than or equal to 5.0.

Method for manufacturing positive electrode active material, and lithium ion battery

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 &#x3bc;m. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

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Kanagawa, Japan

Yumiko Yoneda