Regulating desolvation and homogenized ion flux towards highly reversible dendrite-free zinc anode

Abstract

Aqueous zinc ion batteries (AZIBs) are potential in the energy storage field, however, there are inherent disadvantages that seriously hinder their development, including the dissolution and structural collapse of cathode materials, Zn-dendrite growth, and side reactions at the anode interface. The cycling life and coulombic efficiency suffer from the latter two disadvantages, thus, many artificial interface layers have been prepared to address these issues. Herein, an organic molecule with four thiophene substitution groups, 1,3,5,9-Tetrathiophenylpyrene (TTP), was designed as an artificial layer to suppress dendrites and achieve uniform zinc deposition. This strategy prolonged the lifespan of symmetrical cells with an extremely small polarization voltage of 51 mV at 0.885 mA cm−2. In particular, the strong interaction between TTP and Zn atoms not only promoted the Zn desolvation but also modulated the Zn2+ transport. Ultimately, Zn-dendrite, hydrogen evolution reaction (HER), and side reactions were significantly inhibited. The full cells constructed with V2O5 delivered long-term cycling stability over 6500 cycles with a capacity retention of 80 % after 1250 cycles at 5 A g-1 and excellent rate performance. More importantly, the sulfur-containing functional groups in the organic materials were successfully utilized to resolve the issues of Zn anodes, demonstrating the promising prospects of this strategy.