Chemistry
Electrochemical Impedance Spectroscopy for Characterizing Battery Electrode Interfaces
Quick fact
A single EIS scan can separate the resistance of the electrolyte, the charge-transfer resistance at the electrode surface, and the diffusion of lithium ions—all from one measurement, revealing processes that happen at timescales from microseconds to seconds.
Why this is interesting
You've probably checked a battery's voltage with a multimeter, but what if you could see inside its chemical processes without taking it apart? Electrochemical impedance spectroscopy does exactly that—using a tiny alternating current to map the hidden landscape of a battery electrode.