Semiconductor Energy Laboratory Co., Ltd.

Yohei Momma

Teruaki Ochiai

Takahiro Kawakami

Mayumi Mikami

Masahiro Takahashi

Shuhei Yoshitomi

Takuya Hirohashi

Yumiko Yoneda

Tatsuya Ikenuma

Mako Motoyoshi

Satoshi Seo

Junpei Momo

Ayae Tsuruta

Junya Goto

Saki Obana

Tomohiko Suganoya

Shunpei Yamazaki

Ryota Tajima

Hiroshi Kadoma

Minoru Takahashi

Aya Uchida

Hiroyuki Miyake

Kei Takahashi

Takayuki Ikeda

Takanori Matsuzaki

Munehiro Kozuma

Kazutaka Kuriki

Teppei Oguni

Yoshihiro Komatsu

Yumiko Saito

Shunsuke Adachi

Jo Saito

Jyo Saitou

Shiori Saga

Hiroki Adachi

Tatsuyoshi Takahashi

Hiroki Inoue

Masaki Yamakaji

Kazuhei Narita

Jyo Saito

A battery control circuit with a novel structure, a battery protection circuit with a novel structure, and a power storage device including either of the battery circuits are provided. The power storage device includes a first circuit portion, a second circuit portion, a third circuit portion, and a secondary battery; the first circuit portion has a function of controlling charging of the secondary battery; the first circuit portion has a function of supplying the start time and the end time of the charging of the secondary battery to the third circuit portion; the second circuit portion has functions of generating a first voltage and a first current and supplying them to the third circuit portion; the third circuit portion has a function of generating a second voltage by charging the first current in a capacitor; and the third circuit portion has a function of comparing the first voltage and the second voltage.

Power storage device and method for operating power storage device

A positive electrode active material particle with little deterioration is provided. A power storage device with little deterioration is provided. A highly safe power storage device is provided. The positive electrode active material particle includes a first crystal grain, a second crystal grain, and a crystal grain boundary positioned between the crystal grain and the second crystal grain; the first crystal grain and the second crystal grain include lithium, a transition metal, and oxygen; the crystal grain boundary includes magnesium and oxygen; and the positive electrode active material particle includes a region where the ratio of the atomic concentration of magnesium in the crystal grain boundary to the atomic concentration of the transition metal in first crystal grain and the second crystal grain is greater than or equal to 0.010 and less than or equal to 0.50.

Positive electrode active material particle

A method for forming a positive electrode active material of a lithium ion secondary battery is provided. In the method for forming a positive electrode active material, a first container that includes a mixture of lithium oxide, fluoride, and a magnesium compound and fluoride that is outside the first container are provided in a heating furnace, and the heating furnace is heated at a temperature higher than or equal to a temperature at which the fluoride is volatilized or sublimated. It is further preferable that the fluoride be lithium fluoride and the magnesium compound be magnesium fluoride.

Method for forming positive electrode active material

To increase capacity per weight of a power storage device, a particle includes a first region, a second region in contact with at least part of a surface of the first region and located on the outside of the first region, and a third region in contact with at least part of a surface of the second region and located on the outside of the second region. The first and the second regions contain lithium and oxygen. At least one of the first region and the second region contains manganese. At least one of the first and the second regions contains an element M. The first region contains a first crystal having a layered rock-salt structure. The second region contains a second crystal having a layered rock-salt structure. An orientation of the first crystal is different from an orientation of the second crystal.

Particle, electrode, power storage device, electronic device, and method for manufacturing electrode

To provide a method of forming a positive electrode active material with high productivity. To provide a manufacturing apparatus capable of forming a positive electrode active material with high productivity. Provided is a method of forming a positive electrode active material including lithium, a transition metal, oxygen, and fluorine. An adhesion preventing step is performed during heating of an object. Examples of the adhesion preventing step include stirring by rotating a furnace during the heating, stirring by vibrating a container containing an object during the heating, and crushing performed between the plurality of heating steps. By these manufacturing methods, a positive electrode active material having favorable distribution of an additive at the surface portion can be formed.

Method of forming positive electrode active material, kiln, and heating furnace

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 novel electrode, a novel power storage device, an electrode with less deterioration, an electrode with a high capacity, a long-life power storage device, a power storage device with less deterioration, a power storage device with high energy density, or a highly reliable power storage device is provided. The electrode includes a graphene compound including a graphene layer and a substituted or unsubstituted chain group, and an active material. The graphene layer is bonded to the chain group through a substituent containing silicon. The graphene compound includes a region in contact with the active material in particle form. The active material includes an element A, which is one or more elements selected from elements belonging to Group 1 and elements belonging to Group 2, and an element M, which is one or more elements selected from manganese and nickel. The chain group includes one or more groups selected from a carbonyl group, an ester group, a carboxyl group, an ether group, and an epoxy group.

Electrode and power storage device comprising graphene compound

A positive electrode active material that has high capacity and excellent charge and discharge cycle performance for a secondary battery is provided. A positive electrode active material that inhibits a decrease in capacity in charge and discharge cycles is provided. A high-capacity secondary battery is provided. A secondary battery with excellent charge and discharge characteristics is provided. A highly safe or reliable secondary battery is provided. A positive electrode active material contains lithium, cobalt, oxygen, and aluminum and has a crystal structure belonging to a space group R-3m when Rietveld analysis is performed on a pattern obtained by powder X-ray diffraction. In analysis by X-ray photoelectron spectroscopy, the number of aluminum atoms is less than or equal to 0.2 times the number of cobalt atoms.

Lithium cobalt aluminum oxide positive electrode active material including aluminum-containing coating film and secondary battery

A 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 charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.

Method for manufacturing positive electrode active material, and secondary battery

A positive electrode active material in which a capacity decrease caused by charge and discharge cycles is suppressed is provided. Alternatively, a positive electrode active material having a crystal structure that is unlikely to be broken by repeated charging and discharging is provided. The positive electrode active material contains titanium, nickel, aluminum, magnesium, and fluorine, and includes a region where titanium is unevenly distributed, a region where nickel is unevenly distributed, and a region where magnesium is unevenly distributed in a projection on its surface. Aluminum is preferably unevenly distributed in a surface portion, not in the projection, of the positive electrode active material.

Positive electrode active material, secondary battery, and electronic device

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

A positive electrode active material with high capacity and excellent charging and discharging cycle performance for a lithium-ion secondary battery is provided. The positive electrode active material contains lithium, cobalt, and oxygen, and the spin density attributed to a bivalent cobalt ion and a tetravalent cobalt ion is within a predetermined range. It is preferable that the positive electrode active material further contain magnesium. An appropriate magnesium concentration is represented as a concentration with respect to cobalt. It is also preferable that the positive electrode active material further contain fluorine.

Positive electrode active material and secondary battery

A semiconductor device that detects deterioration of a secondary battery is provided. The semiconductor device includes a power gauge, an anomalous current detection circuit, and a control circuit. The power gauge includes a current divider circuit and an integrator circuit. The anomalous current detection circuit includes a first memory, a second memory, and a first comparator. The integrator circuit can convert a detection current detected at the current divider circuit into a detection voltage by integrating the detection current. The anomalous current detection circuit is supplied with the detection voltage, a first signal at a first time, and a second signal at a second time. The first signal can make the detection voltage at the first time be stored in the first memory and the second signal can make the detection voltage at the second time be stored in the second memory. The first comparator outputs a change from the detection voltage at the first time to the detection voltage at the second time as a first output signal to the control circuit.

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Kanagawa, Japan

Yohei Momma