Nissan Motor Company Limited

Atsushi Itou

Yasuhiko Ohsawa

Manabu Watanabe

Takuya Kinoshita

Tomohiro Kaburagi

Wataru Ogihara

Fumihiro Haga

Tomokazu Yamane

Naoki Ueda

Yuka Aiso

A negative electrode for an electric device includes a silicon-containing alloy containing silicon and tin, a carbon cover layer including a carbon material and covering the silicon-containing alloy, and a negative electrode electric conducting additive. A ratio of an average particle diameter of the silicon-containing alloy to an average particle diameter of the carbon material is 240 or greater. The negative electrode for an electric device and an electric device using the negative electrode can improve cycle durability.

Negative electrode for electric device and electric device using the same

A control device of a secondary battery uses, as material of a positive electrode, positive electrode active material that shows a difference of an open circuit voltage curve between charging and discharging. A storing unit stores, as discharge open circuit voltage information, a relationship between an SOC in a discharge process and an open circuit voltage for each changeover SOC that is an SOC when changing a state of the secondary battery from the charge to the discharge. An SOC calculating unit calculates the SOC of the secondary battery in the discharge process on the basis of a changeover SOC when actually performing the change from the charge to the discharge and the discharge open circuit voltage information stored in the storing unit. It is therefore possible to properly detect the SOC during the discharge.

Secondary battery control device and SOC detection method

Disclosed is a lithium ion secondary battery having a positive electrode, a negative electrode and a non-aqueous electrolyte composition (electrolytic solution), characterized in that: the positive electrode includes a positive electrode active material represented by: aLi[LiM1]O.(1&#x2212;a)LiM2O(where M1 represents at least one kind of metal element selected from the group consisting of Mn, Ti, Zr and V; M2 represents at least one kind of metal element selected from the group consisting of Ni, Co, Mn, Al, Cr, Fe, V, Mg and Zn; and a represents a composition ratio and satisfies a relationship of 0&#x3c;a&#x3c;1); the negative electrode includes a negative electrode active material containing silicon; and the non-aqueous electrolyte composition includes a lithium salt (CFSO)(CFSO)NLi (where m and n each independently represent an integer of 2 or more as a support electrolyte. This lithium ion secondary battery attains a high capacity and good cycle characteristics.

Lithium ion secondary battery

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Kanagawa, Japan

Atsushi Itou