Energy & Fuels, Vol.34, No.9, 11590-11596, 2020
Layered TiS2 as a Promising Host Material for Aqueous Rechargeable Zn Ion Battery
The aqueous zinc-ion battery (ZIB) is one of several promising energy storage systems because of its low cost, nontoxicity, and high safety. In addition, Zn metal exhibits low redox potential in aqueous solution. However, one big obstacle in the development of ZIBs is the dendrite growth and corrosion reaction of Zn anode. Exploration of the Zn host anode material with high reversible capacity and low redox voltage would be an effective strategy. Herein, layered TiS2 is successfully demonstrated as a durable host material for neutral aqueous ZIBs with a relatively low charge voltage of 0.4 V. The TiS2 material delivers a stabilized capacity of 120 mAh g(-1) at 100 mA g(-1), high rate capability (76 mAh g(-1) at 1000 mA g(-1)), and good cycle performance (70% capacity retention after 500 cycles at 1000 mA g(-1)) in a Zn/TiS2 cell. The outstanding electrochemical properties are attributed to the excellent maintenance of TiS2 during cycling in which the Zn2+ cations can be easily inserted/extracted into/from the layered structure with slight structural change, observed from ex situ X-ray diffraction investigation. Mechanism study reveals that TiS2 goes through a reversible (de)interclation reaction in accompany with valence change of titanium element during cycling. This study would benefit the exploration and design of host materials for rechargeable aqueous batteries, especially for the anode.