An Advanced Lithium-Ion Sulfur Battery for High Energy Storage

A lithium-ion battery is reported using a sulfur–carbon composite cathode, a graphite anode, and a dimethoxyethane-dioxolane-lithium bis-(trifl uoromethanesulfonyl)imide (DOL-DME-LiTFSI) electrolyte advantageously added by lithium nitrate (LiNO3) and a selected polysulfi de (Li2S8 ). The suppressed sulfur dissolution, due to the Li 2 S 8 buffer action, as well as reduced shuttle reactions by the fi lm-forming properties of the LiNO3 positively affect the lithium-ion cell behavior in terms of delivered capacity, coulombic effi ciency, and cycle life. The lithium–sulfur cell shows a stable capacity of 750 mAh g −1 for over 200 cycles with an enhanced cycling effi ciency. Furthermore, the full lithium-ion sulfur battery using a graphitebased anode shows a working voltage of about 2 V and delivers a stable capacity of 500 mAh g−1 . The full cell has enhanced safety content, due to the replacement of the lithium metal anode by suitable intercalation electrode, and shows a theoretical energy density as high as 1000 Wh kg−1 at high current rate of 1 C. The remarkable safety level, low materials cost, and high practical energy density, expected to exceed 300 Wh kg−1 , suggest the battery reported is a suitable energy storage system for future applications.