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

Aqueous zinc ion batteries (AZIBs) are potential in the energy storage field, however, there are inherent dis-advantages 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 effi-ciency 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-Tetrathiophe-nylpyrene (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 success-fully utilized to resolve the issues of Zn anodes, demonstrating the promising prospects of this strategy.

Automated summary

This study designs an organic molecule as an artificial layer to address the issues of dendrite growth and uneven zinc deposition in aqueous zinc ion batteries, which demonstrates promising prospects with long-term cycling stability and excellent rate performance. The sulfur-containing functional groups in the organic materials also successfully resolve the problems of zinc anodes.