Investigation of temperature effects of rechargeable aqueous Mg-ion batteries

Among the environmental factors, temperature, as a critical factor, significantly affects battery performance, chemical reactions, phase transitions, interfaces, ion transitions, and battery degradation. In addition, different temperature conditions lead to different adverse effects. Accurate measurement of the temperature inside batteries is important in understanding the effects of temperature for proper battery management. In this study, the effects of temperature in the low and high temperature range were discussed. Also, entropy is a basic thermodynamic parameter to describe the working principle of a battery, which changes under the influence of temperature. Its value can be described from the entropy difference between anode and cathode. However, its origin is based on the individual effects that occur on each half-cell. Here, the entropy of a single electrode relative to the electrolyte used can be measured through the open circuit potential (OCP) difference at various temperatures [fig۱]. The entropy changes (ΔS) MgMn۲O۴@PANI (MMP) composite as cathode material are systematically investigated using an electrochemical thermodynamic measurement system. Their electrochemical activity was investigated using galvanostatic charge/discharge methods and electrochemical impedance spectroscopy (EIS). Temperature effects show an increase in capacity through temperature increase and the optimal temperature is ۳۵°C with an initial capacity of ۳۳۰ mAh.g-۱ with ۴۵% capacity retention after ۴۰ charge/discharge cycles [fig۲]. These results provide valuable information on the fundamental mechanism of voltage fade for thermal management of batteries using these materials. Our work shows that MMP is a promising cathode for Mg-ion batteries (MIBs), which may provide new insights for the development of high-performance MIBs.