Surface modification of Zn anodes with a robust organic-inorganic hybrid interphase for high-performance aqueous Zn-ion batteries

This work reports a facile method to fabricate a robust organic-inorganic hybrid interphase layer on Zn anodes by simply coating the Zn foil with a MAHEPE solution

A hybrid organic-inorganic layer was constructed on Zn to modulate Zn2+ flux for dendrite-free and high-stability metal anodes.

The electrochemical performance of Zn metal anodes in aqueous systems is greatly affected by the formation of dendrites and side reactions induced by unstable SEI and inefficient ion transport. Herein, a strategy for modulating Zn2+ flux and optimizing the electrochemical reaction pathway is proposed by constructing a hybrid organic-inorganic layer on Zn through a simple doctor blade method to achieve efficient and stable Zn plating/stripping. The flexible organic layer serves as a barrier to suppress the direct contact between Zn and H2O, thereby minimizing HER and Zn corrosion. Moreover, this layer induces homogeneous nucleation and Zn2+ flux, promoting uniform Zn plating. After cycling, the organic layer decomposes and reacts with Zn2+ to form Zn3(PO4)2 nanocrystals, which further facilitate Zn2+ migration and maintain optimal electrochemical performance. As a result, the Zn anode exhibits outstanding electrochemical performance with low nucleation overpotential, high Coulombic efficiency, and stable cycling performance over 2000 cycles at 5 mA cm−2 and 50 °C in ZnSO4 electrolyte. Furthermore, the assembled Zn//MnO2 full batteries exhibit excellent cycling stability at 0 °C and 0.5 A g−1, achieving a capacity retention of 80% over 150 cycles. Finally, the Zn//I2 batteries display excellent cycling performance at 60 °C and 1 A g−1, with a capacity retention of 92.9% over 100 cycles. This study provides valuable insights into the design of advanced metal anodes for high-energy and high-power aqueous batteries and electrochemical devices.