Tracking the progression of nonuniform deterioration in a lithium-ion battery by Bragg-edge imaging using the AISTANS compact accelerator-driven neutron source

A commercial lithium-ion battery was studied nondestructively by neutron Bragg-edge imaging at the AISTANS compact accelerator-driven neutron source for the purpose of tracking the progression of nonuniform deterioration of the battery. Neutron transmission spectra with a pixel size of 5 × 5 mm 2 in a 55 × 50 mm 2 area on the battery were obtained. For the negative electrode, graphite, LiC 12 , and LiC 6 crystals were observed in the spectra. Column density (cm −2 ) images of these crystals at three different charge/discharge-cycle states (0, 92, and 200 cycles) were obtained. Obvious nonuniformity in the images were not recognized. However, slight shifts of average column densities of all pixels after 200 cycles, which might suggest power-storage degradation of the battery sample, were observed with the LiC 6 crystals.