Microelectrodes for Battery Materials

The ability to measure current and voltage is core to both fundamental study and engineering of electrochemical systems, including batteries for energy storage. Electrochemical measurements have traditionally been conducted on macroscopic electrodes on the order of 1 cm or larger. In this Perspective, we review recent developments in using microscopic electrodes (<100 μm) for the study of battery materials. Microelectrodes allow us to explore spatiotemporal regimes that are not accessible with macroscopic electrodes. Temporally, microelectrodes can generate ultrahigh current densities, enabling the distinction between solid electrolyte interphase (SEI) kinetics and metal deposition kinetics. Spatially, they confine electrochemistry to single particles, allowing us to study their intrinsic properties. We outline future opportunities for the use of microelectrodes for future studies of battery systems. We propose their use for analyzing the electrochemistry of other reactive metals and exploring the potential of combining them with in situ imaging techniques.