The objective of this activity is to define the specific conditions necessary to achieve safe passivation of Lithium (Li) ion battery cells at end of mission, and to design, manufacture and test an electrical power management system for CubeSats allowing battery passivation.
Targeted Improvements: Enable small satellites to comply with clean space requirements, enabling missions beyond low Earth orbit.
The trend in small communication satellites is for longer mission durations and operation in higher orbits. To enable this, satellites need to demonstrate that they can be safely decommissioned at the end of their mission. Passivating batteries is one of the most important decommissioning activities to be performed at the end of life. If batteries are not fully discharged and disconnected from the charging circuit, then they pose an increasing explosion risk. Large satellites are equippedwith bypass devices to carry out this function.
Small satellites currently do not have passivation and isolation devices and cannotcomply with the requirement to passivate the battery packs. In the past, battery passivation by forcing a deep discharge of thebattery cells has been investigated, but has not yet been adopted. This activity will research, develop and test passivation methods forLi ion battery cells and implement the most promising method in a CubeSat power system using commercially available cells thatare commonly used in small satellites. Minimum battery cell capacity to be handled is 20Wh. The solution shall be scalable.