Reasons for the effect of the amount of electrolyte on the performance of lithium–sulfur cells

Influence of the Electrolyte on the Internal Resistance of Lithium−Sulfur Batteries Studied with an Intermittent Current Interruption Method

“…In any event, these observations indicate that electrolyte decomposition is the principal cause of resistance increase and cell failure in these cells. This is also in agreement with the dependence of cycle life on electrolyte volume reported elsewhere ,…”

“…The choice of solvent and salt influences the solubility and reactivity of intermediate polysulfide species, and the concentrations of these species in the electrolyte during operation will depend on the ratio of electrolyte to sulfur in the cell. The strong influence of the ratio of electrolyte to sulfur (often called the E/S ratio) on the cycling performance has been well‐demonstrated elsewhere . As the electrolyte is gradually destroyed by the negative electrode, it can be expected that the cycle life can be determined both by the amount of electrolyte and the susceptibility to decomposition of its components, as has also been demonstrated .…”

“…This is also in agreement with the dependence of cycle life on electrolyte volume reported elsewhere. [16,17] It is also noted that in some cases, and only where the electrolyte volume is low, a resistance increase is also seen towards the very end of charge, coincident with the expected oxidation of polysulfides to elemental sulfur. This increase may also be understood to be a result of pore blocking and/or 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 electrode passivation by solid sulfur, made more severe by the restricted electrolyte volume.…”

“…The strong influence of the ratio of electrolyte to sulfur (often called the E/S ratio) on the cycling performance has been well-demonstrated elsewhere. [13][14][15][16] As the electrolyte is gradually destroyed by the negative electrode, it can be expected that the cycle life can be determined both by the amount of electrolyte and the susceptibility to decomposition of its components, as has also been demonstrated. [16,17] Clearly, the internal resistance of a LiÀS cell can be expected to vary significantly not just with DoD/DoC, but with cycle number, and electrode and electrolyte composition.…”

A Robust, Water‐Based, Functional Binder Framework for High‐Energy Lithium–Sulfur Batteries

“…We wish to emphasise that this calculation takes into account the electrolyte excess—the electrolyte mass is approximately four times that of the electrode coating—in spite of the fact that the coin cells used in this work contain a relatively large amount of empty space. We estimate that approximately 300 Wh kg −1 with these electrodes is realistic if the electrolyte:sulfur ratio can be reduced to 3 μL mg S −1 and if the negative electrode thickness can be reduced to the order of 30 μm; although it must be noted that both of these factors will impact negatively on the cycle life …”