High-Performance Dual-Ion Battery Based on a Layered Tin Disulfide Anode.

Energy issues have attracted great concern worldwide. Developing new energy has been the main choice, and the exploitation of the electrochemical energy storage devices plays an important role. Herein, a high-performance dual-ion battery system is proposed, which consists of a graphite cathode and SnS 2 anode, with a high-concentration lithium salt electrolyte (4 M LiTFSI). The benefits from the typical sandwich-like layer structure of SnS 2 are as follows: the highest discharge specific capacity of the battery could reach 130.0 mA h g -1 at a current density of 100 mA g -1 , and even under an ultra-high current density of 2000 mA g -1 , the highest capacity of 66.3 mA h g -1 is still achieved, with an outstanding capacity retention over 100% after 1000 cycles. Inspiringly, this system delivers an excellent low self-discharge of 1.19%/h, surpassing most of the reported dual-ion batteries. In addition, the working mechanism and structural stability are also investigated by X-ray diffraction and Raman spectra, indicating a good reversibility. These results reveal that this graphite/SnS 2 dual-ion battery system could provide a promising alternative for a future high-performance energy storage device.