キューブサット用電源の軌道上特性分析に用いる民生用リチウムイオン電池の内部抵抗評価法の検討

抄録

We evaluated the internal resistance of commercial cylindrical lithium-ion batteries (LIB) as a power source for micro/nanosatellites including cubesats by two kinds of measurements, electrochemical impedance spectroscopy (EIS) and current-rest-method (CRM) to understand and predict the battery condition on orbit. Comparing the EIS and CRM response, the observed internal resistance of CRM was larger than that of EIS, presumably reflecting the difference in chemical situation inside the battery: the increse in the CRM resistance might be due to the overvoltage relaxation coming from continuous charging/discharging. The two measurements also revealed that the internal resistance of LIBs at low temperature, where the power supply of the CubeSats experiences, were more than double compared to those in a mild environment for larger satellites. Moreover, incredibly high resistance at a higher state of charge (SOC) was observed, especially in low-temperature EIS measurement. Such resistive behaviors strongly affect the battery performance on orbit, and probably lead to the risks in the satellite operation.