Sanyo Electric Co., Ltd.

Shoichiro Sawa

Atsushi Fukui

Maruo Kamino

Hiroshi Minami

Yasuyuki Kusumoto

Mariko Torimae

A lithium secondary battery of the present invention comprises a positive electrode formed by disposing a positive-electrode mixture layer containing a positive-electrode active material and a positive-electrode binder, on a surface of a positive-electrode current collector; a negative electrode formed by sintering a negative-electrode mixture layer containing a negative-electrode binder and a negative-electrode active material containing silicon and/or a silicon alloy, disposed on a surface of a negative-electrode current collector; a separator disposed between the positive electrode and the negative electrode; and a nonaqueous electrolyte; wherein an electrode unit obtained by setting the positive electrode and the negative electrode opposed to each other through the separator and rolling them in spirally rolled state is placed in a cylindrical battery container and wherein a curvature radius of the negative-electrode mixture layer opposed to the positive-electrode mixture layer through the separator in the spirally rolled state is 1.5 mm or larger.

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Tokushima, Japan

Shoichiro Sawa