LITHIUM-ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a lithium-ion secondary battery which hardly causes an internal short circuit by a portion between a positive electrode plate uncoated portion and a negative electrode active material where a large current easily flows and between the edge of the positive electrode plate coated portion and the negative electrode active material, when an internal short circuit is brought about caused by a hole formed by the crash or the like of the separator.

SOLUTION: The lithium ion secondary battery comprises an electrode group in which a positive electrode plate coating a positive electrode active material composed of a lithium compound oxide on a positive electrode current collector and a negative electrode plate coating a negative electrode active material composed of carbon on a negative electrode current collector are wound through a separator. An uncoated portion is provided at the inner circumference and the outer circumference of the positive electrode plate, and an insulating substance is coated continuously on the coated portion edge of the positive electrode plate outer circumference and on a part or the whole face including at least a portion opposed to the negative electrode active material of the positive electrode plate outer circumference uncoated portion continuing thereto.

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