Asymmetry in the Solvation–Desolvation Resistance for Li Metal Batteries

Li metal electrode is the ultimate choice use in Li ion batteries as high-energy storage systems. An obstacle to its practical realization is Li dendrite formation. In this study, the desolvation resistance of the Li metal electrode, which is strongly related to the inhibition of Li dendrite formation, is investigated. By applying a Laplace transform impedance technique, the desolvation/solvation resistances were successfully separated and analyzed in cells using liquid electrolytes containing different lithium salts, revealing asymmetry in the desolvation/solvation resistances of Li metal electrodes. The desolvation resistances, which supposedly require large amounts of energy derived from the strong interaction between Li + ion and solvents, were smaller than the solvation resistances. It has also been revealed that the larger resistance in the desolvation process is effective for suppressing Li dendrite formation further.