A Proposed Methodology for Assessment of Li-ion Cell Suitability and Safety for Suborbital Vehicle Applications

Abstract

Lithium-ion batteries are a feasible solution to store energy efficiently. However, in safety-critical environments such as the suborbital rockets, the introduced technologies do not may compromise safety. This research explores the possibility of replacing Ni-MH batteries with Li-ion batteries. However, before replacing technologies, the reliability of Li-ion cells needs to be evaluated, and the potential benefits must be considered against the risks to ensure the mission’s success. The main objective is to ensure the safety and integrity of suborbital missions during the technology transition. To assess the technology exchange, a method where the battery cell experiences a sequence of tests that cover aspects of safety encountered during the vehicle missions, such as vacuum, capacity, short circuit behavior, over-current discharge, behavior at higher environment temperature, and pulsed discharge behavior. To experience the proposed method, two Li-ion cells commercial off-the-shelf (COTS) from different manufacturers are evaluated. The results indicated that only one of the two cell models evaluated can substitute the Ni-MH. This research concludes that replacing Ni-MH cells with Li-ion cells is feasible, for such an application. The proposed acceptance flow design based on the test collectively validates the replacement, showing that the Li-ion cells can offer reliability, safety, and efficiency to suborbital vehicles to fulfill this mission profile.