Lithium-ion battery development at Eagle-Picher

Abstract

Eagle-Picher Technologies, LLC (EPT) has been involved in the design, development and production of special purpose batteries since the late 1940's. Among these niche markets, EPT has been the supplier of choice for the majority of all satellite applications. As energy density requirements for the aerospace industry batteries have increased, the chemistry of these batteries has evolved from nickel-cadmium (NiCd) to nickel-hydrogen (NiH2). Most recently, the lithium-ion technology has proven to be the next generation of choice. With cell voltages more than 3 times that of nickel-hydrogen and a very low volume configuration, these high energy density, lithium-ion secondary cells are very attractive for use on future spacecraft. This paper summarizes the past and present activities of EPT in the quest to develop the lithium-ion technology for spacecraft applications, as well as environmental issues and future development work. Specific technical challenges include the ability of lithium-ion secondary cells to achieve the hgh cycle life and long calendar life required for use on highreliability spacecraft, and the difficulties in scaling up cell technology (15 Ah) to larger sizes (100 Ah) required for spacecraft power systems. With significant improvements over existing cell technology, the lithium-ion system will provide tremendous savings in lift-off cost as well as package flexibility. Cycle life, mechanical and thermal designs are discussed.