Self‐Assembled Supramolecular Host–Guest Composite Enables Interfacial Regulation Toward Dendrite‐Free Aqueous Zinc Metal Batteries

ABSTRACT The instability of zinc anodes during reversible deposition and dissolution in the aqueous electrolyte constitutes a critical bottleneck limiting the lifespan of aqueous zinc‐ion batteries (AZIBs). Herein, we utilize a straightforward and supramolecular self‐assembly approach involving 4‐sulfocalix[6]arene (SCA[6]) and N,N’‐dimethyl‐9,9’‐biacridinium dinitrate (LCG), driven by cooperative host‐guest recognition and electrostatic forces. The spontaneous interfacial assembly of these components enables the construction of a protective interphase on zinc anodes and functions as a “molecular switch” to regulate the Zn 2 + solvation structure, facilitate ion transport, and accommodate volumetric fluctuations during cycling. Consequently, the LCG/SCA[6]‐modified interface effectively mitigates corrosion and dendrite growth, thereby significantly enhancing the electrochemical stability and cycling performance of AZIBs. As a result, the (LCG/SCA[6]) 2 ‐Zn symmetric cell can maintain stable operation for over 3800 h at 1 mA cm −2 and 1 mAh cm −2 . The (LCG/SCA[6]) 2 ‐Zn||I 2 coin cell retains a specific capacity of 200.50 mAh g −1 with a capacity retention rate of 87.25% at 2 A g −1 even after 14 000 cycles. Considering the low cost and simplicity of LCG/SCA[6] film fabrication, this supramolecular composite presents a promising strategy for enhancing the stability of zinc anodes.