Uniform wide-channel gel polymer electrolyte with consistent head-to-tail supramolecular arrangement for enhanced aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising energy storage solution due to their safety, cost-effectiveness, and high energy density. However, challenges such as dendrite growth, electrolyte stability, and ionic conductivity present significant hurdles. In this work, we developed a carboxylated cyclodextrin (CCD)-based gel polymer electrolyte (CCD-GPE) with highly ordered head-to-tail aligned CCD units, achieved through self-assembly with polyethylene oxide (PEO). This CCD-GPE exhibits a uniform channel structure that enables efficient Zn²⁺ flux distribution and effectively suppresses zinc dendrite growth. The extended carboxyl groups in the CCD-GPE regulate the Zn²⁺ solvation structure, contributing to a stable electrolyte-electrode interface. This innovation achieves impressive electrochemical performance, including an ion conductivity of 18.5 mS cm⁻¹, a superior ion transference number (0.64), and 95 % capacity retention over 1000 cycles at 2.0 A g⁻¹ in Zn||MnO₂ cells. Moreover, CCD-GPE not only reduces side reactions such as hydrogen evolution but also prolongs Zn anode's lifespan by promoting uniform Zn²⁺ migration. These advancements position CCD-GPE as a strong candidate for practical applications in aqueous Zn-ion batteries, paving the way for enhanced energy storage solutions.