An insight into charge/discharge behaviors of lithium/sodium‐sulfur conversion batteries and their similarity to the lithium/sodium‐ion intercalation batteries: Relation of delivered capacity vs current rate.

This paper proposes a mathematic relationship between obtained capacity and the corresponding current rate for the Li‐S and Na‐S conversion batteries. Using experimental data on different conditions of the Li/Na‐S batteries, taken from literature, it is established that the inverse value of obtained capacity is changing linearly with respect to square root of the corresponding applied current rate. The theoretical‐based relationship has been established for the Li‐ion and Na‐ion batteries. Therefore, this paper proposes similar behavior for the conversion and intercalation batteries. The proposed relationship and its beyond approach proffer estimations of: alteration of capacity by rate, optimal cathode mass, corresponding reaction components, and fraction of (in)active particles. Also, they offer a quantitative criterion for performance and rate‐capability, the capability to justify observed phenomena, and also qualification of the powder, preparation, and assembling of the cell. [ABSTRACT FROM AUTHOR]