<i>In Situ</i> Fluorinated Layer Enables a High-Performance Shape-Memory Zn-I<sub>2</sub> Battery.

Gao, Fei; Sun, Jingbo; Qin, Hongyu; Li, Yutong; Yu, Miao; Huang, Yan · Nano Lett · 2026

basic_science · Level V

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Abstract

Despite the considerable promise of flexible Zn-I<sub>2</sub> batteries for next-generation electronics, their development remains constrained by the polyiodide shuttle effect that severely compromises electrochemical stability and a lack of intrinsic shape adaptability. To address these challenges, this study successfully constructs a Zn-I<sub>2</sub> battery with both high electrochemical stability and excellent shape-memory functionality through the approach of "shape-memory skeleton, corrosion-resistant coating, and fibrous architecture". The <i>in situ</i> formed inert fluorinated coating (FeF<sub>2</sub>/ZnF<sub>2</sub>) shows a good barrier effect for polyiodides, and the fiber Zn-I<sub>2</sub> battery demonstrates high electrochemical stability, maintaining a capacity retention of over 96% after 250 cycles. Furthermore, due to the excellent shape-memory effect of the NiTi skeleton, combined with the flexibility of the fibrous structure, the battery achieves rapid (within 2 s) and stable (recovery rate above 70%) shape restoration. This work facilitates the development of flexible and shape-memory batteries.