Advances in battery design for aerospace applications

Abstract

Since the launch of Russia's Sputnik-1 satellite on October 4,1957, the aerospace industry has been obsessed with an endless hunger for more mass and volume efficient power storage systems for its orbital spacecraft. Mass and volume aboard these spacecraft are at a premium with costs reaching into the tens of thousands of dollars per kilogram (kg) of launched mass. Over the years, the launcher industry has steadily increased its capacity for propelling more and more mass into orbit. While there is still a major emphasis on scientific exploration of space, there are a growing number of commercial spacecraft which are being pkced into orbit strictly for the purpose of generating revenues. For these programs, increased time on orbit means increased revenues. With less of the overall mass and volume budget spent on power storage, longer spacecraft orbital lifetimes can be achieved by increasing the amount of fuel carried onboard. Increased time on orbit can, in turn be translated into a need for more advanced power storage systems with even longer cycle life capabilities. tional systems onboard these vehicles. During this period, battery manufacturers have continued to produce the best battery cells and batteries that the technology of the day would allow. These systems have included 1) commercially available batteries such as standard lead-acid and nickel-cadmium and 2) custom designed power systems, engineered and manufactured specifically for the aerospace industry. These specialized systems include high reliability, aerospace nickel-cadmium and nickel-hydrogen cells and batteries. In addition, development efforts are currently underway to flight qualify a number of new and exciting power storage technologies. These new technologies include not only the advanced nickel-hydrogen electrochemistries, but the secondary lithium systems, lithium-ion (Li-ion) and lithium-polymer as well. During the forty year history of spaceflight, both primary (non-rechargeable) and secondary (rechargeable) battery systems have been used to provide power for the many and varied operaBattery Technologies Nickel-Cadmium (Ni-Cd) The nickel-cadmium battery has been in use in a variety of applications since the early 1900's. It has been developed into one of the most widely used secondary systems in use today. Two of the more advanced applications are 1) aircraft engine starting/auxiliary power units and 2) onboard satellite power storage. The following is a list of some of the significant features which 35th Aerospace Sciences Conference and Exhibit; Reno, Nevada, January 6-9, 1997 have led to Ni-Cd battery's widespread use within