Beyond Lithium-Ion: Lithium- Sulphur Batteries for Space?

Lithium-ion (Li-ion) batteries are established as the state of the art [1] rechargeable batteries for terrestrial and space applications today since the launch of Proba 1 satellite in 2001. [2]At the moment there is strong interest by all stakeholders related or influenced by the battery markets on two systems: The rechargeable Li-air (Li-O 2 ) and Li-Sulfur (Li-S) batteries. There have been many studies on both technologies during the past decades but since major challenges are still to be overcome, none of the two technologies has been yet commercialized.Li-S is believed to reach mass commercialization towards the end of the decade whereas Li-O 2 is expected to be available after 2030. Therefore, discussion to follow hereby will focus on Li-S.Li-S cells are regarded as one of the most promising systems for next generation batteries due to their high theoretical capacity, the abundant and low cost sulfur resources and lithium-ion comparable cathode production techniques. [RD3] If Li-S batteries were to be successfully developed and reach their theoretical maximum, batteries over six times lighter than the conventional lithium-ion ones, would be available. [RD4]Sion Power in the US and OXIS Energy Ltd. in Europe are the major companies producing Li-S cells.Prototype Cells were procured from Oxis Energy, UK and characterisation tests were performed at ESA-ESTEC Battery Life Test Facility in Noordwijk, Netherlands. The results are presented here, mainly in order to enhance basic understanding on existing technology in Europe and show relevant trends.Consequences at power system level, if this technology was to be adopted for satellite applications, are also addressed in this paper.