Effects of discharging rates on Lithium-Sulfur batteries via simulation

Li-S battery, with Li metal as anode and sulfur as cathode, exhibits high energy density and outperforms Lithium-ion batteries (LIBs) in energy density, and this promises its great potential for future utilization in battery-based aircraft. Given its important role in the promotion of battery-based aircraft, effects of discharging rates for Li-S batteries are of great interest to the community these days. In this study, with effects of discharging rates from from 0.2C (300 minutes) to 0.5C (120 minutes), 1C(60 minutes), 2C(30 minutes), 4C (15 minutes), to highest 6C (10 minutes) during discharging process considered, a 1D homogeneous electrochemical model was introduced. The effects of increasing discharging rates for typical Li-S single layer pouch cells were probed via simulation. It is found that the higher the discharging rates, the higher the polarization/overpotential within Li-S cells. Meanwhile, for a given discharging rate, detailed distribution of Li+ concentration within the Li-S full cell is also well probed. All simulation results agree well with published experimental result, and this 1D model can be further utilized by designers to assess various effects during charging/discharging rates within Li-S batteries and greatly exaccerlate design for Li-S battery packages.