Feasibility study of low-temperature operatable power supply for on-orbit material exposure tests

Abstract

The feasibility of a low-temperature operable electric power system for space environment exposure experiments was discussed from the viewpoint of a secondary battery. After exploring various types of storage batteries, we evaluated two kinds of lithium-ion batteries (LiBs) as a candidate, and confirmed that one of them, LiB-B, can be charged with 0.1C rate at a low temperature of -20°C, and maintained more than half of its capacity even at -45°C with 0.2C discharging, besides, it can be operated stably at an extremely low temperature of -50°C. Such high performance of the LiB-B reveals the possibility to construct an electric power system for exposure experiments with minimal assistance, such as a heater or an insulation material. It is also expected to be applicable to power systems of microsatellites and other spacecraft. Moreover, we also suggested some materials for thermal control to improve the battery operation and its reliability according to the above-mentioned characteristics of LiB-B.