Temperature instantaneous online monitoring methods of thermal runaway based on electrode process principle

With the properties of suitable operating voltage, high energy density and stable structure, sodium-ion batteries are widely used in energy storage systems as the most promising alternative to lithium-ion batteries. However, the thermal runaway of sodium ion battery has occurred easily, which poses a great threat to the whole safety system of battery. This paper discusses a method to predict and prevent thermal runaway of sodium-ion batteries by measuring electrochemical impedance of battery. Based on the electrode material with the role of temperature control detector, the working temperature inside the battery can be directly reflected and monitored in real time, and the method is not only simple, fast, accurate, efficient, but also low-cost, which can achieve real-time on-line monitoring of the temperature inside the battery. In this work, using the sodium-ion batteries for study, it has been found that the charge transfer resistance (Rct), peak current (Ip), diffusion coefficient (D0) and cell internal temperature rare the key factors in battery effeciency. Therefore, the corresponding functional relationship can be established to effectively control the normal operation of the battery by exploring instantaneous detection of temperature sensitive electrochemical parameters, and timely disposes the battery with abnormal temperature to avoid the thermal runaway.