Sanyo Electric Co., Ltd.

Panasonic Corporation

Hidekazu Tamai

Taizou Sunano

Tetsuo Nanno

A nonaqueous electrolyte secondary battery includes an electrode assembly including a positive electrode, a negative electrode, and a separator and a nonaqueous electrolyte. The separator includes a porous resin sheet having at least a three-layer structure consisting of an A-layer, a B-layer, and a C-layer stacked in that order. The average thermal expansion coefficient of each of the A-layer and the C-layer at a temperature of 0&#xb0; C. to 50&#xb0; C. is 100 ppm/K or more less than the average thermal expansion coefficient of the B-layer at a temperature of 0&#xb0; C. to 50&#xb0; C.

Separator for nonaqueous electrolyte secondary batteries and nonaqueous electrolyte secondary battery

Provided are a positive electrode active material capable of suppressing the reduction in capacity of a battery and the generation of gas during storage at high temperature in a charged state and a nonaqueous electrolyte secondary battery including the positive electrode active material. A positive electrode active material particle () includes a lithium transition metal oxide particle () containing a halogen atom and rare-earth compound particles () attached to the surface of the lithium transition metal oxide particle (). The amount of the halogen atom present on the surface of the lithium transition metal oxide particle () is 5 mass percent or less of the total amount of the halogen atom contained in the lithium transition metal oxide particle (). A rare-earth element making up the rare-earth compound particles () is one other than yttrium and scandium.

Positive electrode active material and nonaqueous electrolyte secondary battery

An all-solid-state lithium secondary cell has a laminate, and a pair of external current collectors. The laminate is shaped into substantially a rectangular parallelepiped and is made of a positive electrode, a negative electrode, and a solid electrolyte between the positive and negative electrodes. The external current collectors are disposed at both ends of the laminate to support side faces of the laminate. One of the current collectors is connected to the positive electrode and the other to the negative electrode. A chamfered shape or an R-chamfered shape is provided at the edges and along the ridges of the laminate.

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Kyoto, Japan

Hidekazu Tamai