Mitsui Minings & Melting Co., Ltd.

Tomoyoshi Matsushima

Kiyotaka Yasuda

Yoshiki Sakaguchi

Akihiro Modeki

Hitohiko Honda

Masahiro Hyakutake

Makoto Dobashi

Kazuko Taniguchi

Takeo Taguchi

Shinichi Musha

Yoshiki Sakaguschi

Kayoko Shinzawa

A negative electrodefor a nonaqueous secondary battery has an active material layercontaining active material particles. The particlesare coated at least partially with a metallic materialhaving low capability of lithium compound formation. The active material layerhas voids located between the metallic material-coated particleswith a void fraction of 15% to 45%. The metallic materialon the surface of the particles is preferably present throughout the thickness of the active material layer. The active material particlesare preferably of a silicon-based material. The active material layerpreferably contains 1% to 3% by weight of an electroconductive carbon material based on the weight of the active material particles

Negative electrode for nonaqueous secondary battery

A negative electrodefor a nonaqueous secondary battery, has an active material layercontaining active material particles. The active material layerhas a metallic materialdeposited among the particles by electroplating. The negative electrodehas a large number of holesopen on at least one side thereof and extending through the thickness of the active material layer. The negative electrodefurther has a pair of current collecting layersandadapted to be brought into contact with an electrolyte. The active material layeris between the current collecting layersand. The holesopen on the negative electrodepreferably have an opening area ratio of 0.3% to 30%. At least one of the pair of the current collecting layersandpreferably has a thickness of 0.3 to 10 &#x3bc;m.

A negative electrode for a non-aqueous electrolyte secondary cell includes a current collector an, formed on a surface or both surfaces thereof, an active material structure containing an electroconductive material with a low capability of forming a compound with lithium, and the active material structure includes 5% to 80% by weight of active material particles containing a material having a high capability for forming a compound with lithium. The active material structure can include an active material layer containing the active material particles and a surface-covering layer on the active material layer.

Negative electrode for nonaqueous secondary battery, process of producing the negative electrode, and nonaqueous secondary battery

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Ageo, Japan

Tomoyoshi Matsushima