Cationic Adsorption-Induced Microlevelling Effect: A Pathway to Dendrite-Free Zinc Anodes

Dendrite growth represents one of the most significant challenges that impede the development of aqueous zinc-ion batteries. Herein, Gd³⁺ ions are introduced into conventional electrolytes as a microlevelling agent to achieve dendrite-free zinc electrodeposition. Simulation and experimental results demonstrate that these Gd³⁺ ions are preferentially adsorbed onto the zinc surface, which enables dendrite-free zinc anodes by activating the microlevelling effect during electrodeposition. In addition, the Gd³⁺ additives effectively inhibit side reactions and facilitate the desolvation of [Zn(H₂O)₆]²⁺, leading to highly reversible zinc plating/stripping. Due to these improvements, the zinc anode demonstrates a significantly prolonged cycle life of 2100 h and achieves an exceptional average Coulombic efficiency of 99.72% over 1400 cycles. More importantly, the Zn//NH₄V₄O₁₀ full cell shows a high capacity retention rate of 85.6% after 1000 cycles. This work not only broadens the  application of metallic cations in battery electrolytes but also provides fundamental insights into their working mechanisms.