Vehicle Energy Japan Inc.

Yasuo Arishima

Hiroyuki Toshiro

Keiichiro Ohkawa

Hironori Sasaki

Ryohhei Nakao

Motonari Kifune

A lithium ion secondary battery with increased durability and capacity includes a positive electrode, a negative electrode, and a separator. The positive electrode includes a current collector foil and an electrode mixture layer disposed on a surface of the current collector foil. The positive electrode mixture layer includes a superficial layer portion and a deep layer portion. The superficial layer portion opposes the negative electrode via the separator. The deep layer portion is disposed between the superficial layer portion and the current collector foil. The superficial layer portion contains positive electrode active material particles having an average particle diameter larger than an average particle diameter of positive electrode active material particles contained in the deep layer portion. A space ratio between the positive electrode active material particles in the superficial layer portion is lower than a space ratio between the positive electrode active material particles in the deep layer portion.

Lithium ion secondary battery and method for manufacturing same

An appropriate upper limit voltage is set to enable maximum charging performance of a secondary battery to be exhibited while effectively suppressing degradation of the secondary battery. An assembled battery control unit determines an upper limit voltage during charge of the secondary battery and calculates chargeable power of the secondary battery based on the upper limit voltage. The assembled battery control unit has an upper limit voltage calculating unit which calculates a voltage history of the secondary battery based on time series data of a voltage of the secondary battery and which calculates the upper limit voltage based on the voltage history.

Battery control apparatus

An object of the present invention is to provide a method for manufacturing a secondary battery with enhanced insulating reliability without degrading the performance of an active material mixture layer formed on an electrode. The present invention provides a method for manufacturing a prismatic secondary battery () including a negative electrode () having a negative electrode current-collecting foil (), a negative electrode mixture layer () formed thereon, and an insulating layer () formed on the negative electrode mixture layer (). The method of the present invention includes a step of forming the negative electrode mixture layer () and the insulating layer () by concurrently applying an active material mixture slurry and an insulating layer dispersion liquid to the negative electrode current-collecting foil (). Each ceramic particle () has a plate shape with an aspect ratio greater than or equal to 2.0 and less than or equal to 5.0. The particle size of each mixture particle () is greater than the length of the long side of each ceramic particle ().

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Hitachinaka, Japan

Yasuo Arishima