In Situ Fluorinated Layer Enables a High-Performance Shape-Memory Zn–I 2 Battery

Despite the considerable promise of flexible Zn–I 2 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 2 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 in situ formed inert fluorinated coating (FeF 2 /ZnF 2 ) shows a good barrier effect for polyiodides, and the fiber Zn–I 2 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.