Tailoring the Electrode Interface Microenvironment to Stabilize Zn Metal Anode

Zn metal is the most attractive anode material for aqueous batteries, yet it encounters challenges from dendrites. Here, based on lanthanum trifluoromethanesulfonate (La(OTf)₃)-based electrolyte, the idea of tailoring the electrode interface microenvironment (ion concentration, solid electrolyte interphase (SEI) and electric field) is proposed to stabilize the Zn metal anode. The theoretical and experimental results show that the reconstruction of the electrolyte microstructure by OTf^- and the capture of SO₄ ^2- by La³⁺ enhance the liquid-phase mass transfer, which alleviates the ion concentration gradient on the anode surface. Meanwhile, the electrolyte decomposes to form a favorable inorganic-rich SEI. Importantly, the adsorbed La³⁺ homogenizes the electric field intensity at the tip of the anode surface. Benefiting from the improved interface microenvironment, the Zn electrodeposition behavior is efficiently regulated, endowing the self-elimination behavior of the regenerated dendrites. As a proof-of-concept, the Zn metal anode shows a highly reversible plating/stripping cycling in both Zn||Cu (7000 cycles) and Zn||Zn cells (3600 h). Also, the NH₄V₄O₁₀||Zn pouch cell operates stably for over 500 cycles and exhibits a low-gassing behavior.