Resumen
A robust lithium-sulfur (Li–S) battery is constituted by a wide range of optimized fundamental parameters (e.g., amount of electrolyte, electrolyte additive, sulfur loading density, and the size of sulfur particles). In this paper, some other often-neglected “trivial” parameters (including assembly pressure of the coil cells, thickness of spring/lithium foil in coin cells, sheet number of separator, and cut-off voltage) of Li–S batteries have been demonstrated to show pronounced effects on the battery performance. Our results indicate that the coin cell assembly pressure and sheet number of the separator play the important roles in suppressing polysulfide shuttling over battery cycling, which improves significantly the cycling life of Li–S batteries. The thickness of springs/lithium foils also affects the battery performance greatly. When switching the cut-off voltage of 1.5–3.0 V to narrower ones (1.7–2.5 V or 1.8–2.6 V), the cycling life of batteries at 0.2 C can be further enhanced to >300 cycles while with no drastic polysulfide shuttling. Adjusting these trivial parameters can thus synergistically improve the cycling performance of Li–S batteries.