High-Power Large Format Lithium Ion Batteries

Saft America, inc. Space and Defense Division (SDD), located in Cockeysville, Maryland, is the world leader in providing state of the art Li-ion systems for the demanding defense and space markets. Recent efforts have focused on the industrialization of the technology. Since 2004 Saft SDD has been developing a higher volume manufacturing capability of the entire cell and battery manufacturing processes. This effort is focused under two ManTech programs. The Army ManTech Program with TARDEC focuses on high power batteries for use in military ground vehicles. The USAF ManTech Program with AFRL focuses on ultra high power cells for use in aviation batteries. The goals of both programs are to industrialize the high performance technology so that they are available to the military as reliable products at an affordable cost, while improving the technology.

Efforts to date have yielded improvements in performance, reliability, and cost. Advances have been realized for improving the power and cold temperature performance of the high power cells. Power in excess of 20kW/kg has been realized. The improved power performance from the cells improves the overall efficiency of the energy storage system. Power efficiencies in excess of 95% have been demonstrated for typical military hybrid vehicle duty cycles of 150A continuous cycling. This high power efficiency allows for low heat generation in a large battery system, with less than 800W of heat generation for a 400V hybrid vehicle battery pack. Storage and operation at demanding temperature extremes has also been developed and industrialized. Operation at temperature less than -40°C has also been successfully demonstrated and high temperature stability has also been improved. Plant operational improvements and design activities, with an emphasis on manufacturability, have led to a lean production operation for the electrode, cell, and battery manufacturing activities. These efforts have led to a dramatic reduction in cell cost since 2004, resulting in a large cost avoidance to the military.