Sanyo Electric Co., Ltd.

Panasonic Energy Co., Ltd.

Mitsunori Miyanari

Kei Kobayashi

Atsushi Mizawa

Syunsuke Natsumeda

Masashi Takigawa

Sanae Hashitani

A non-aqueous electrolyte secondary battery according to one aspect of the present invention includes: a positive electrode plate in which a positive electrode mixture layer containing a positive electrode active material is formed on a positive electrode current collector; a negative electrode plate in which a negative electrode mixture layer containing a negative electrode active material is formed on a negative electrode current collector; a separator; a non-aqueous electrolyte; a sealing member; and an outer casing. The negative electrode active material contains graphite and a silicon material. The silicon material contains silicon oxide represented by SiO(0.5≤x<1.6) and a silicon-lithium silicate composite in which a silicon phase is dispersed in a lithium silicate phase represented by LiSiO(0<z<2). The amount of the silicon-lithium silicate composite is 33% by mass or more and 93% by mass or less relative to the silicon material.

Non-aqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery using a silicon compound as a negative electrode active material, suppress deformation of a negative electrode. An embodiment includes a winding type electrode body in which a positive electrode and a negative electrode are spirally wound with at least one separator interposed therebetween. In a negative electrode mixture layer, a silicon compound is contained as a negative electrode active material. A winding-start side end of the negative electrode mixture layer extends to a winding-start end side of the electrode body past a winding-start side end of a positive electrode mixture layer. A length Y (mm) of a portion of the negative electrode mixture layer extending from the winding-start side end of the positive electrode mixture layer and a rate X (percent by mass) of the silicon compound with respect to the total mass of the negative electrode active material satisfy a relationship of Y&#x2265;3X&#x2212;15 (6&#x2264;X&#x2264;15).

Nonaqueous electrolyte secondary battery

Growing community of inventors

Osaka, Japan

Mitsunori Miyanari