Hitachi Maxell, Limited

Ube Industries, Inc.

Itaru Gosho

Masayuki Yamada

Haruki Kamizori

Yusuke Nakamura

Koji Abe

Kei Shimamoto

Toshiharu Shimooka

Akira Inaba

Kazutaka Matsuo

Satoshi Kono

Yuta Kawamoto

A lithium secondary battery of the present invention includes: a positive electrode; a negative electrode; a nonaqueous electrolytic solution; and a separator. The positive active material contains a lithium-containing composite oxide containing nickel. A molar ratio of a total nickel amount with respect to a total lithium amount contained in the entire positive active material is 0.05 to 1.0. The nonaqueous electrolytic solution contains 0.5 to 5.0 mass % of a phosphonoacetate-based compound represented by the following General Formula (1). In the Formula, R, R, and Rindependently represent an alkyl group, an alkenyl group, or an alkynyl group having 1 to 12 carbon atoms, which may be substituted by a halogen atom, and 'n' represents an integer of 0 to 6. 

Lithium secondary battery

A lithium secondary battery positive electrode according to the present invention is a lithium secondary battery positive electrode including a positive electrode material mixture layer containing a positive electrode active material and a conductivity enhancing agent on one or both sides of a current collector, wherein the positive electrode active material contains a lithium-containing composite oxide, the conductivity enhancing agent contains carbon fibers having an average fiber length of 10 nm or more and less than 1000 nm and an average fiber diameter of 1 nm or more and 100 nm or less, and the content of the carbon fibers in the positive electrode material mixture layer is 0.25 mass % or more and 1.5 mass % or less.

Lithium secondary battery positive electrode and lithium secondary battery

There is provided a lithium secondary battery including a positive electrode, a negative electrode, a nonaqueous electrolyte liquid and a separator, that is subjected to a constant-current constant-voltage charge with a stop voltage of more than 4.25V before its use. The lithium secondary battery uses the nonaqueous electrolyte liquid having contained 0.1 to 5 mass % of a phosphonoacetate compound represented by the following general formula (1), and having contained 0.1 to 5 mass % of 1,3-dioxane. In General Formula (1), each of R, Rand Ris independently hydrocarbon groups having a carbon number of 1 to 12 with or without substituent of a halogen atom, and n is 0 to 6 integers. 

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Ibaraki, Japan

Itaru Gosho