Development and manufacture of a large, multi-cell lithium thionyl chloride reserve battery

A high power reserve battery has been developed to provide electrical energy for a family of ocean buoys. Some of the key development and manufacturing features of this program are outlined. The battery weighs approximately 145 lbs and is packaged in the nose of a MK 46 torpedo size store. Electrolyte, stored in a reservoir, is distributed to the 21 cells via a unique manifolding system. Activation is initiated by an explosive squib, and a stored energy system within the reservoir provides motive power. The 21 cells are divided into two sections. Performance requirements include extended operation at 4 kW constant power discharge. Each battery contains a large number of components, and automation has been developed to facilitate manufacture. A continuous coating process is used for the manufacture of cathode stock. Robots are used for the conversion of cathode stock into finished cathodes and for welding electrode tabs to current collectors. A comprehensive system of nonoperating electrical tests is used to determine product operability and safety. These tests include capacitance measurements to assure continuity of the unactivated series stacks and the integrity of the cell/manifold/activation system