Presentation Information
[EDP1-01]Prototype System for Metallic Inspection using HTS SQUIDs
*Saburo Tanaka1, P.W M.H Polkotuwa2, Takeyoshi Ohtani1,2 (1. National University Corporation Toyohashi Univ. of Technology (Japan), 2. Nikka Densok Limited (Japan))
Keywords:
SQUID,Metallic contaminants,Inspection,Ditection,Battery components
Magnetic metallic contaminant inspection system using multiple high Temperature (HTS) SQUID gradiometers for battery products has been developed. Finding ultra-small metallic contaminants is a big issue for manufacturers producing commercial products. The quality of lithium ion batteries can be deteriorated by the inclusion of tiny metallic contaminants. When the contamination does occur, the manufacturer of the product suffers a great loss to recall the tainted products. Outer dimension of metallic particles less than 50 micron cannot be detected by a conventional X-ray imaging. Therefore a high sensitive detection system for small foreign matters is required. However most of the case, the matrix of an active material coated sheet electrode is magnetized and the magnetic signal from the matrix is large enough to mask the signal from contaminants. Thus we have developed a detection system based on a SQUID gradiometer and a horizontal magnetization to date. For practical use, we should increase the detection width of the system by employing multiple sensors. And also a roll to roll or reel to reel process is required. In this paper, we present the multi-channel high-Tc SQUID gradiometer system for inspection of a lithium ion battery cathode with width of 60 mm to 70 mm wound on a roll. As a result, small iron particles of about 18 micron in a sheet were successfully measured. This result suggests the system is the promising tool for the detection of contaminants in a lithium ion battery.