Chen Renjie

Electrolyte materials for high energy density lithium-sulfur secondary battery

Rechargeable Li-S secondary batteries have received ever-increasing attention recently due to their high theoretical specific energy density, wide material sources, low cost and being environmental friendly. Thus, the Li-S battery is becoming the most promising candidate for energy storage devices. But the current research shows that the polysulfides formed as intermediates during the discharge process can dissolve easily into the electrolyte, which will result in shuttle phenomenon. On the one hand, the high solubility of polysulfides leads to the loss of active material; on the other hand, the shuttle mechanism results in reduced columbic efficiency and poor cycle ability. So suppressing the polysulfides dissolution along with inhibiting the occurrence of shuttle phenomenon can effectively improve the whole performance of lithium sulfur battery. In this paper, the electrolytes used effectively in Li-S batteries are reviewed in detail including the organic liquid electrolytes, ionic liquids electrolytes, solid-state electrolytes, gel-like electrolytes, microporous polymer electrolytes, composite-solid polymer electrolytes along with the glass-ceramic electrolytes. Furthermore, the possible development prospects are also discussed.

Cathode materials for high-specific-energy Li-S batteries

Li-S batteries have long been considered as one of the most potential candidates of novel multi-electron reaction system. Given the complete reaction of Li with S to form Li2S, Li-S batteries exhibit a theoretical specific capacity of 1675 mA h g-1 and energy density of ~2600 W h kg-1, which are much higher than those of state-of-the-art Li-ion batteries. In addition, S is naturally abundant with low environmental impact. However, wide applications of Li-S battery are hindered by many inherent problems. Here we review the recent advances in the cathode materials for high-specific-energy Li-S batteries.