Altering the solvation structure enabling high-performance Li-S batteries at low temperature

Abstract

In order to prevent the progression of global warming caused by extreme carbon emissions, batteries, which are eco-friendly energy storage devices, have recently been adopted to various transports. Lithium-sulfur batteries has an advantage of high energy density (1675 mAh gs-1), so it is motivated to be used at various transportations. Accordingly, in order to be applied to the transportations, a wider range of temperature driving is emerging as an important factor. However, due to the formation of the lithium polysulfide clustering in the cathode, the discharge capacity is degraded and the instability of Li as the anode is increased, thereby degrading energy density and stable operation is difficult. Therefore, in this study, by introducing nitrate (NO3-) salt with high affinity toward lithium ions, the formation of lithium polysulfide clustering was suppressed and the reversibility of Li anode was improved. As a result, designing high energy-density lithium-sulfur batteries in a low temperature was possible. In order to verify the amended performances, experiments were conducted in a pouch cell, and it was confirmed that the pouch cell was able to stably driven for 100 cycles and energy density was improved.