Airtightness inspection method and airtightness inspection apparatus for sealed battery

摘要

A soft packaged sealed battery is contained in an airtight container. The airtight container is decompressed and images of the surface shape of the sealed battery in the airtight container before and after decompression are captured by a CCD camera or the like. Whether or not airtightness of the sealed battery is maintained is determined based on a change in the captured images, e.g. a change in the surface shape appearing as luminance differences of pixels. By this determination method, highly accurate airtightness determination is realized by eliminating the influence of invisible fine creases on a sealed battery surface.

主权项

1. An airtightness inspection method for a sealed battery having a battery element sealed into a battery case in a negative pressure environment, the battery case being made of a deformable film, the method comprising:
enclosing the sealed battery in an airtight container; measuring a surface shape of the sealed battery enclosed in the airtight container; decompressing the airtight container under a predetermined negative pressure that is smaller in absolute pressure value than a negative pressure of the negative pressure environment applied for sealing the battery element into the battery case; measuring a surface shape of the sealed battery in the airtight container in a decompressed state where the predetermined negative pressure is maintained; and determining airtightness of the sealed battery based on a change in the surface shape of the sealed battery between before decompression of the airtight container and in the decompressed state of the airtight container.