Modeling and Verification of Li-Ion Cells Under Accelerated Life Testing

Rechargeable Lithium-Ion (Li-Ion) cell technology is attractive for MDA space satellites. But, because this technology is relatively new and is still evolving, its performance and behavior must be characterized by laboratory life testing that is very time consuming and expensive. A requirement for a 10-year real-time cell life test could delay the incorporation of Li-Ion cell technology into MDA satellites that are essential for national security. Accelerated life testing can be used to force cell degradation earlier than real time testing, enable identification of the source of the degradation, and speed the process of qualifying cell technology for space flight. However, there are questions of its applicability because cells are not operated exactly the same way during accelerated life tests as on satellite missions, and there is likelihood of introducing additional failure modes during accelerated testing. Global Aerospace Corporation (GAC), in collaboration with NASA"s Jet Propulsion Laboratory (JPL), plans to answer the question"is accelerated life cycle testing feasible for Li-Ion cells?"To answer this question, we will (a) develop test procedures and collect laboratory data and (b) develop a complementary high fidelity, first principles-based, verified software tool to assist and guide accelerated life testing laboratory work.