Sanyo Electric Co., Ltd.

Mariko Torimae

Atsushi Fukui

Yasuyuki Kusumoto

Hiroshi Minami

Maruo Kamino

Hiroshi Nakamura

Hisaki Tarui

Katsunobu Sayama

Hiromasa Yagi

Shouichirou Sawa

Shoichiro Sawa

A lithium secondary battery includes an electrode assembly having a positive electrode (), a negative electrode () having a negative electrode current collector and a negative electrode active material layer formed on a surface of the negative electrode current collector and composed of a binder and negative electrode active material particles containing silicon and/or a silicon alloy, and a separator () interposed between the electrodes. The electrode assembly is impregnated with a non-aqueous electrolyte. The binder contains a polyimide resin represented by the following chemical formula (1): where R contains at least a benzene ring, and n is within the range of from 10 to 100,000, and the negative electrode active material particles have an average particle size of 5 &#x3bc;m or greater.

Lithium secondary battery and method of manufacturing the same

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.

Lithium secondary battery and method for manufacturing the same

A negative electrode for a lithium secondary cell having a collector composed of an electroconductive metal foil and, provided on the surface thereof, an active material layer containing active material particles containing silicon and/or a silicon alloy and a binder, characterized in that the binder has mechanical characteristics of a tensile strength of 50 N/mmor more, an elongation at break of 10% or more, a strain energy density of 2.5&#xd7;10J/mmor more and a coefficient of elasticity of 10000 N/mmor less, and preferably characterized in that the collector has mechanical characteristics of a tensile strength of 80 N/mmor more, a proportional limit 30 N/mmor more, an elongation at break of 1.0% or more and an elastic elongation limit of 0.03% or more.

Negative electrode for lithium secondary cell and lithium secondary cell

A rechargeable lithium battery including a negative electrode made by sintering, on a surface of a conductive metal foil as a current collector, a layer of a mixture of active material particles containing silicon and/or a silicon alloy and a binder, a positive electrode and a nonaqueous electrolyte, characterized in that the nonaqueous electrolyte contains carbon dioxide dissolved therein.

Lithium secondary battery including a negative electrode which is a sintered layer of silicon particles and/or silicon alloy particles and a nonaqueous electrolyte containing carbon dioxide dissolved therein and method for producing same

A negative electrode for a rechargeable lithium battery which is obtained by sintering under a non-oxidizing atmosphere, in the form of a layer on a surface of a metal foil current collector, an anode mix containing a binder and particles of active material containing silicon and/or a silicon alloy; the negative electrode being characterized in that the metal foil current corrector has projections and recesses on its surface, the projection is shaped to have a recurved side face portion that curves more outwardly as it extends closer to a distal end of the projection, and the binder penetrates into spaces defined by the recurved side face portions.

Negative electrode for rechargeable lithium battery and method for fabrication thereof

A lithium secondary battery comprising an electrode in which an active material layer which includes an active material that electrochemically occludes and releases lithium is formed on a current collector, wherein cracks are formed in the active material layer by occlusion and release of lithium ions and thereafter a solid electrolyte is formed in the cracks in the active material layer.

Lithium secondary battery and method for manufacturing thereof

A negative electrode for a lithium secondary battery obtained by providing an active material layer containing particles of an active material and a binder on a surface of a current collector which is an electrically conductive metal foil, and sintering the layer under a non-oxidizing atmosphere; wherein the mean diameter of the particles of the active material is not smaller than 1 &#x3bc;m and not greater than 10 &#x3bc;m, and the particle size distribution of the particles is such that at least 60 volume % of the particles are in a range of not smaller than 1 &#x3bc;m and not greater than 10 &#x3bc;m.

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Kobe, Japan

Mariko Torimae