Interfacial electric field defect repair engineering enable highly reversible Zn metal anodes

Abstract

The inherent defects present on Zn anodes consistently result in uneven electric field, which promote dendrite growth and a range of side reactions, thereby significantly impeding the performance of Zn anodes for aqueous zinc-ion batteries (AZIBs). Herein, we propose an interface electric field defect repair engineering to construct highly reversible Zn anodes through the sulfonated cobalt phthalocyanine (SCP) electrolyte additive. The SCP can be complexed with Zn²⁺ ions and form an adsorption layer on Zn anode due to its strong polar sulfonic acid groups, thereby reconstructing the dissolved sheath structure of Zn²⁺ ions and repair the electric field defects on Zn anode through physical adsorption. In addition, Co atoms in SCP have superior zincophilic properties and could induce Zn-oriented deposition. Consequently, the calculation results indicate that SCP exhibits a high adsorption energy across all crystal planes of Zn anode, leading to uniform zinc deposition. The SCP/ZnSO₄ electrolyte achieves a long cycle life of the Zn anode of 2710 h, a high coulombic efficiency of 99.96 % and high performance of Zn//MnO₂ full battery (77.14 % retention after 300 cycles at 5 A g⁻¹). This work proposes a strategy to achieve highly reversible Zn anodes through repairing the interfacial electric field defects, thus providing a new perspective for improving the performance of AZIBs.