We expect that this new ability to directly measure shuttle currents will provide greater insight into the performance differences observed with various additives and electrode modifications that are aimed at suppressing the rate of shuttling of polysulfide ions and increasing the cycle life of lithium-sulfur cells.
In Ref. 14 a direct shuttle current measurement (see section "Direct shuttle current measurement methode") and a basic shuttle flux model were introduced. In their study, the authors used potentiostatic charging to measure the shuttle current at a specific voltage level.
The shuttling of polysulfide ions between the electrodes in a lithium-sulfur battery is a major technical issue limiting the self-discharge and cycle life of this high-energy rechargeable battery. Although there have been attempts to suppress the shuttling process, there has not been a direct measurement of the rate of shuttling.
The continuous shuttle current calculation for 10 °C visualized over the OCV for uOff of 0 mV, ±10 mV and ±16 mV. During the continuous shuttle current measurement, a shuttle current is measured at 2.448 V between the self-discharge cycle and the continuous cycle by the direct shuttle current measurement method.
Lithium Sulfur (Li-S) batteries are a promising energy storage technology with very high theoretical limits in terms of specific capacity and specific energy. However, these batteries suffer from high self-discharge rates, associated with a low coulombic efficiency due to the polysulfide shuttle mechanism.
We present a phenomenological analysis of the shuttling process and simulate the shuttle currents as a function of the state-of-charge of a cell. We also demonstrate how the rate of decay of the shuttle current can be used to predict the capacity fade in a lithium-sulfur cell due to the shuttle process.