Self‐Supported Flexible Film F‐Pt 1 /MnO 2 With Long Bending Cyclability Towards Robust Wearable Al‐Air Batteries

Flexible Al‐air batteries are promising power supplies for wearable electronics, yet the practical application is severely hindered by poor mechanical stability of powder‐based cathode and inferior alkaline corrosion resistance. Here, derived from a jelly‐like precursor, we develop a binder‐free self‐supported flexible film F‐Pt 1 /MnO 2 to address these issues. Combined with structural characterizations and finite element analysis simulations, the self‐supported film features interconnected hierarchical pore channels and a mechanically robust network that enhances its long bending cyclability from 0 to 180° over 5000 cycles with a slight △R/R 0 alternation of 2%. Benefiting from the binder‐free structure, the film retains structural integrity with no material exfoliation after 15 days of hot alkaline aging treatment. When employed as a cathode in a flexible Al‐air battery, it delivers a peak power density of 77.9 mW cm −2 and stable discharge performance for over 27 h, exceeding most of the recently reported catalysts. Due to the battery's stable output under wide‐scale bending angles, a wearable device is further driven that can detect long‐term pulse signals under frequent deformation. This work provides a facile and general strategy for the rational design and fabrication of robust free‐standing film for wearable energy storage and conversion devices.