Importance of 'unimportant' experimental parameters in Li-S battery development

Lithium-sulphur batteries are among the most promising systems for the next generation of rechargeable lithium batteries. Whereas a wide range of factors contribute to the overall performance of the Li-S system, reported optimization procedures typically focus on the development of novel structured cathodes. Here, the importance of often-neglected experimental parameters contributing to the performance of Li-S systems is demonstrated. Specifically, the effects of varying the amount of electrolyte, the salt concentration and the type of electrolyte additive are presented and factors that improve cycling stability are discussed. Some of the parameters, such as sulphur-particle size and the type of conductive additive used in the electrodes, affected the cell's performance less than might be expected. Long-term cycling (up to 500 cycles) with a low amount of electrolyte is demonstrated. Our results suggest that parameters related to the electrolyte are more important for improving the overall performance than those concerning the electrode structure.