Probing Impedance and Microstructure Evolution in Lithium–Sulfur Battery Electrodes

Lithium–sulfur chemistry, despite being a promising candidate for energy storage due to its higher theoretical capacity, is faced with several critical challenges. Practical operation of Li–S batteries demonstrates lower capacity, poor rate capability, and insufficient cycle life, which can be related to the underlying physicochemical interactions at the electrodes. Typical carbon-based porous cathodes undergo coupled electrochemical, chemical, and microstructural evolution during operation. In this work, the mesoscale interaction resulting from the underlying chemical/electrochemical complexations and microstructural evolution is studied in order to elucidate the transient impedance behavior in Li–S battery mesoporous carbon cathodes. The discharge product (e.g., Li2S) precipitation is shown to affect impedance evolution with correlational dependence on the porous cathode microstructure attributes. This mesoscale impedance analytics can be a valuable virtual probing tool for Li–S battery electrochemical performance.