Strontium titanate modified separator regulates ion flux to stabilize aqueous zinc ion battery anodes

Zinc (Zn) metal is an ideal anode material for aqueous zinc ion batteries (ZIBs), but the development of ZIBs is limited by the severe dendrite growth of Zn anode. Herein, a strontium titanate (SrTiO3) coated separator is prepared to solve this issue, concretely, the SrTiO3 (STO) modified separator exhibits special dielectric properties and well-filling of surface pores, enabling homogenize ion flux and inducing uniform deposition of Zn2+. The electrochemical measurements indicate that the Zn||Cu asymmetric cell with STO separator can stably cycled 780 cycles with an average Coulombic efficiency of 99.7%. Meanwhile, the Zn||Zn symmetric cell displays a long cycle life of 1800 h at a current density of 1 mA cm-2 and an area capacity of 0.5 mAh cm-2. Therefore, this study presents a novel approach that improves the deposition behavior of Zn2+ and represses Zn dendrite to achieve steady and long-life ZIBs.

Automated summary

In this study, a strontium titanate (STO) coated separator was prepared to solve the problem of severe dendrite growth of zinc anode in aqueous zinc ion batteries (ZIBs). The modified separator with STO coating exhibited special dielectric properties and well-filled surface pores, which enabled homogenize ion flux and induced uniform deposition of Zn2+. Electrochemical measurements showed that the Zn||Cu asymmetric cell with STO separator cycled stably for 780 cycles with an average Coulombic efficiency of 99.7%. Meanwhile, the Zn||Zn symmetric cell displayed a long cycle life of 1800 hours at a current density of 1 mA cm-2 and an area capacity of 0.5 mAh cm-2. Thus, this study presents a novel approach to improve the deposition behavior of Zn2+ and suppress Zn dendrite growth for achieving stable and long-life ZIBs.