Capacity utilization in small Li/SOCl/sub 2/ cells

The performance evaluation of small Li/SOCl/sub 2/ batteries for implantable medical devices requires accelerated testing for projecting service-life of the product. Accelerated discharge testing was conducted on standard cell samples stored at 60/sup 0/C. The charge utilizations were obtained to 3.0 and 0.5V levels with constant loads of 2, 6.3, and 10K..cap omega... The results were greatly affected by voltage polarization, a voltage step, and self-discharge during electrical discharge. Another study of similar cells in implantable-type hardware provided information on how capacity loss occurs during discharge. These cells, discharged at rates between 0.51 and 0.08mA, were monitored by a calorimeter. The patterns observed showed that heat output increases with current and also varies in an unusual pattern with depth of discharge and cell impedance. Most of the discharge inefficiency at the lowest rates can be accounted for by integrating the heat vs. capacity curves, assuming the principal heat producing reaction is anode corrosion.