Investigation of LiFePO₄/MWCNT cathode-based half-cell lithium-ion batteries in subzero temperature environments

The main challenge that hinders lithium-ion batteries in space applications is their poor performance at subzero temperatures. Such poor performance is primarily due to the low ionic conductivity and freezing of the electrolyte, leading to the loss of battery capacity. This research investigates the behavior of lithium-ion batteries at low temperatures by employing electrochemical and material characterization techniques. Based on the electrochemical behavior of the battery cells, lithium-ion batteries’ performance declined rapidly at − 30 °C. The major findings indicate that charging at low-temperature conditions increases the impedance, which slows down the reaction kinetics affecting the intercalation of lithium ions. According to the results obtained from the ex situ material characterization analysis, the main factor that induces this behavior is the freezing and the decomposition of the electrolyte at the cathode-electrolyte interphase and the mechanical degradation of the active materials of the cathode. These changes lead to interfacial instability and considerable development of resistance to the flow of charges. The findings in this study contribute to the development of lithium-ion batteries for low temperature and space applications by understanding the behavior of lithium-ion batteries in subzero temperature environments.