The significance of imperceptible current flowing through the lithium reference electrode in lithium ion batteries

Reference electrode is a promising tool for understanding cathode/anode electrodes behavior and monitoring the battery status. Lithium metal, due to its fast electrode reaction kinetics, has been widely used as a reference electrode in the lithium-ion battery. However, the life of the lithium metal reference electrode (Li-RE) during the battery charge/discharge process is one of the big challenges for its application. The Li-metal is continuously consumed due to the spontaneous and irreversible reaction with the electrolyte, which is generally considered as the main reason for the failure of Li-RE. In this work, a straightforward method is used, that only changes the circuit of the Li-RE in the testing, the life of which is significantly increased by more than 3.5 times. Moreover, for the first time, an extension of utilization life for Li-RE by reducing the current that follows through it is reported. This finding provides an important guideline for designing in-situ Li-RE and improving its life.