Aqueous zinc-iodine batteries (AZIBs) are promising candidates for grid-scale energy storage owing to their high safety and low cost. However, their practical application is hindered by severe polyiodide species shuttle. Herein, we have constructed well-defined cationic microenvironments by assembling poly(diallyldimethylammonium chloride) (PDDA) onto multi-walled carbon nanotubes (PDDA@MWCNT) and flat graphite sheets (PDDA@GS). This design enables strong electrostatic anchoring of polyiodide species and allows systematic differentiation of curvature-dependent immobilization behaviors. The optimal PDDA@MWCNT cathode exhibits a high Coulombic efficiency of 98.3% at 0.1 A·g⁻¹, along with exceptional durability of 82,000 cycles at 3.0 A·g⁻¹ and 3,569 cycles at 0.1 A·g⁻¹ (nearly one year), far surpassing its planar PDDA@GS counterpart. Combined experimental characterizations and density functional theory (DFT) calculations reveal that the curvature-guided PDDA configuration markedly enhances iodine adsorption and accelerates interfacial charge transfer, thereby suppressing polyiodide shuttling and self-discharge. This work demonstrates molecular curvature engineering as a powerful and generalizable strategy for governing iodine chemistry, offering new design principles for high-performance AZIBs.

Sodium-sulfur (Na–S) batteries that utilize earth-abundant materials of Na and S have been one of the hottest topics in battery research. The low cost and high energy density make them promising candidates for next-generation storage technologies as required in the grid and renewable energy. In recent years, extensive efforts have been devoted to the diversity and functionalities of Na–S batteries, aiming to extend their potential applications across multiple temporal and spatial dimensions. Here, we summarize the unconventional designs for the functionalities of Na–S batteries such as flexible batteries, solid-state cells, flame resistance, and operation at extreme temperatures. By highlighting these design strategies that help to realize the functionalities, we hope this review offers a pathway to foster the bright future of Na–S batteries in diverse applications.