In lithium-ion batteries, a 'Reference Electrode (RE)', also known as a reference electrode half-cell, is an essential component of the electrochemical system. It serves as a stable reference point for measuring the potential of the working electrode in the battery.
The reference electrode is typically composed of a metallic conductor, such as lithium or lithium alloy, that is in contact with a reference electrolyte. The reference electrolyte is often a salt solution that contains the same lithium-ion species as the electrolyte in the battery cell.
During battery operation, the reference electrode remains at a constant potential, which is known as the reference potential. This fixed potential allows for accurate measurements of the potential difference between the working electrode and the reference electrode. By comparing the potentials, researchers and engineers can assess the electrochemical performance of the battery and monitor its state of charge and health.
The reference electrode is commonly used in various electrochemical techniques and measurements. It provides a stable and reproducible reference point, enabling accurate analysis of the electrochemical processes occurring within the battery.
It's important to note that the reference electrode is not a part of the active battery system and does not directly participate in the electrochemical reactions. Instead, it serves as a reference point for measuring and understanding the behaviour of the working electrode and the overall performance of the battery cell.