Electronic Band Alignment of Aqueous Zinc Anode & Favorable Chalcogenide Cathode- Cu2NiSnS4 (CNTS) Battery and its Performance Analysis

Abstract Aqueous zinc-ion batteries are one of the most efficient and promising energy storage devices due to immense amount advantages such as non-toxicity, safety, cost-effectiveness, and earth abundance. However, zinc metal has the redox potential of -0.76V which is comparable and suitable for aqueous systems as an anode. Herein, quaternary chalcogenide wurtzite Cu 2 NiSnS 4 (CNTS) has been demonstrated as a stable electrode material for aqueous Zinc-ion battery pouch cell with high capacity and the potential of 1.34V. The band alignment of the Zn/CNTS also has been studied by the combined comparison of the optical band gap of CNTS and cyclic voltammetry curve analysis. CNTS delivers the specific capacity of 261mAh/g at the current density of 62.5mAh/g and good cycle performance in Zn/CNTS pouch cells. The striking electrochemical properties are ascribed to the excellent stability of CNTS while galvanostatic cycling, in which the cation Zn 2+ can be intercalated/deintercalated at the chalcogenide cathode CNTS. The intercalation results in the formation of ZnS while cycling which has been analyzed by Raman spectra after the cycling of pouch cell. The mechanism study discloses the reversible shuttling of Zn 2+ cations into/from CNTS.