Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Sachie Yuasa

Akira Tsujiko

Tomitaro Hara

Keiko Wasada

Takeshi Abe

Daisuke Teramoto

Takuichi Arai

Yohei Shindo

Hiroshi Sawada

Tsuyoshi Yano

Chikaaki Okuda

Mamoru Mizutani

Osamu Hiruta

Yuichi Itou

Takahito Imamine

Tsuyoshi Sasaki

Yuichi Ito

Youji Takeuchi

An object is to provide a method of charging and maintaining a lithium ion secondary battery which method is capable of preventing a decrease in the capacity of the battery. Another object is to provide a battery system capable of preventing a decrease in battery capacity, and a vehicle and a battery-mounted device which have such a battery system mounted therein. A method of charging and maintaining lithium ion secondary batteriesusing positive active material particlesmade from a two-phase coexistence type positive active material PM in a positive electrode plateincludes an overcharge step Sfor charging the lithium ion secondary batteries to bring their SOC (State of Charge) SC into an overcharge SOC not higher than 100% but higher than a target SOC, a return discharge step Sfor discharging, after the overcharge step, the lithium ion secondary batteries to make their SOC equal to the target SOC, and a maintaining step S

Method of charging and maintaining lithium ion secondary battery, battery system, vehicle and battery-mounted device

The lithium secondary battery positive electrode provided by the present invention has a positive electrode collector and a positive active material layer formed on the collector. The positive active material layer is composed of a matrix phase containing at least one particulate positive active material and at least one binder, and an aggregate phase dispersed in the matrix phase, constituted by aggregation of at least one particulate positive active material and containing substantially no binder.

Lithium secondary battery and positive electrode for the battery

A positive electrode for a lithium secondary battery provided by the present invention includes a positive electrode active material layer having a particulate positive electrode active material constituted by a composite oxide containing lithium and at least one type of transition metal element, and at least one type of binding material constituted by a polymer compound having at least one functional group, and a conductive carbonaceous coating film is formed on a surface of the positive electrode active material. Further, the polymer compound constituting the binding material is molecularly bound to carbon atoms constituting the carbonaceous coating film of at least a part of the positive electrode active material, whereby a composite compound is formed from the polymer compound molecularly bound to the carbon atoms and a carbon network constituting the carbonaceous coating film containing the carbon atoms.

Method of manufacturing a positive electrode with a condensation reaction initiated by heating and reduced pressure

A lithium-ion secondary battery with excellent durability is provided using a two-phase coexisting compound as a positive electrode active material. This lithium-ion secondary battery is provided with an electrode body having a positive electrode containing a positive electrode active material and a negative electrode containing a negative electrode active material, and a non-aqueous electrolyte solution containing a lithium salt in an organic solvent. The positive electrode active material is mainly composed of a two-phase coexisting compound containing lithium, and also contains particles of a lithium-transition metal oxide with a layered structure. The particles of the layered oxide have an average particle diameter of 2 &#x3bc;m or less, and the percentage content thereof in the positive electrode active material is 5 mass % or less.

Non-aqueous electrolyte solution type lithium ion secondary battery

A lithium ion secondary battery provided by the present invention has a positive electrode having a current collector and a positive electrode composite layer provided on the current collector. The current collector contains a metal element A as a main component thereof. The positive electrode composite layer contains a two-phase compound containing lithium as a positive electrode active material. The positive electrode composite layer also contains as an additive a compound having a metal element B, in a composition thereof, that has a higher ionization tendency than the metal element A.

Non-aqueous electrolyte lithium ion secondary battery

Provided is a secondary battery system which can accurately detect a state of a secondary battery system (such as a secondary battery state and a secondary battery system failure). The secondary battery system () includes dV/dQ calculation means which calculates a dV/dQ value as a ratio of a change amount dV of a battery voltage V of a secondary battery () against a change amount dQ of an accumulation amount Q when the accumulation amount Q of the secondary battery () is changed. The secondary battery system () detects the state of the secondary battery system () by using the dV/dQ value.

Secondary battery system

A battery control system controls an external charging unit in a vehicle including a vehicle body, engine, motors, secondary battery, and the external charging unit, and includes a degradation detecting unit that detects degradation of the secondary battery, during charging of the second battery by the external charging unit.

Battery control system and vehicle

A control method for a lithium ion secondary battery includes performing a charging step of charging the lithium ion secondary battery with a predetermined quantity of electricity when the battery voltage of the lithium ion secondary battery has decreased to a lower limit battery voltage that is set at a value that falls within a range higher than (B&#x2212;C) V and lower than or equal to (B&#x2212;C+0.2) V where a maximum value of a positive electrode potential of a flat portion in a discharge positive electrode potential curve is B (V) and a negative electrode dissolution potential is C (V). It is possible to suppress a dissolution of a negative electrode current collector of the lithium ion secondary battery to prevent the service life of the lithium ion secondary battery from shortening because of an internal short circuit.

Control method for lithium ion secondary battery, and lithium ion secondary battery system

The invention provides a method of diagnosing a malfunction in an abnormal voltage detecting apparatus, which includes breaking an electrical connection between a secondary battery () and an abnormal voltage detecting apparatus () and connecting the abnormal voltage detecting apparatus to a direct current voltage generating portion () that is different from the secondary battery (), applying direct current voltage that has a predetermined voltage value that is outside of a normal voltage range to the abnormal voltage detecting apparatus () using the direct current voltage generating portion, and determining that there is a malfunction in the abnormal voltage detecting apparatus if the abnormal voltage detecting apparatus does not determine that the voltage is abnormal.

Growing community of inventors

Okazaki, Japan

Sachie Yuasa