Studies of high reliability long-life Li/SO2 cells

Abstract To satisfy the need for a 5-year battery, a long-term test of Li/SO 2 cells was initiated. Premature failures were observed and a program was undertaken to identify the cause of these failures. Based on the results of this program, changes in the cell design were made which gave rise to the Sandia modified Li/SO 2 cell having improved long-life performance. Several batches of modified cells have been manufactured during the past five years. Acceptance testing of incoming cells from each batch revealed batch-to-batch variation in performance as well as a small proportion of cells with low capacity. A program to develop a non-destructive methodology for identifying cells with low inherent capacity was initiated. Several relevant non-destructive measurement parameters were identified. A decision tree screening technique, based on these parameters, was developed to identify those cells having low capacity.