Electrochemical Behaviors of Lithium Powder Anode in Lithium-Sulfur Battery

Abstract

A lithium powder electrode is applied as an anode in a lithium-sulfur battery system to examine the effects of changes in the anode surface area on electrochemical behavior. Besides preventing dendrite growth, as in other lithium-ion batteries, the lithium powder anode achieves an elevation in lithium-ion transfer, which can be attributed to an increase in the exchange current density caused by expansion of the surface area of the anode. This promotion of lithium-ion diffusion also leads to an increase in lithium-ion transfer near the cathode site and contributes to the reversible reaction between the lithium ion and sulfur. As a result, the reversibility in cathodic reactions is enhanced, thereby improving its specific capacity and retention. Scanning electron microscopy and X-ray photoelectron spectroscopy reveal that the morphology of the cathode is maintained throughout the process, and a solid electrolyte interphase (SEI) with lower electrolyte decomposition can be constructed. Impedance analysis also confirms that a stable electrochemical reaction is achieved with low resistance values.