In Situ Neutron Imaging Of Alkaline and Lithium Batteries

Abstract

We report on in situ tomographic (three dimensional) measurements of alkaline and lithium primary AA cells during constant current discharge to zero charge. The measurement spatial resolution was 150 um, and the relative uncertainty due only to counting statistics was of order a few percent for a one hour measurement time. The results for alkaline cells are consistent with the current understanding of discharge. The degree of anode utilization is seen to depend on discharge current, with a 0.5 A resulting in more complete utilization than that of a 1 A discharge. The lithium primary cell data has an additional systematic uncertainty due to beam hardening, which can be corrected. In these corrected images, the center of the jelly roll, which is initial empty, fills with cathode material and changes in the cell are similar for a 1 A and 0.1 A discharge rate.