Dynamic and Hierarchical Hydrogen‐Bonding Network Enables Self‐Healing Polymer Electrolyte for Ultra‐Long Cycle Life Rechargeable Aluminum Batteries

Abstract Rechargeable aluminum batteries (RABs) are considered promising large‐scale energy storage technologies due to the high theoretical capacity, low cost, and high safety of aluminum. Nevertheless, the performance of current liquid RABs is significantly compromised by persistent challenges such as uncontrolled dendrite formation, corrosion and leakage, and parasitic gassing. Addressing these limitations necessitates the development of advanced polymer electrolytes capable of enhancing stability and significantly extending the cycle life of RABs. Herein, a self‐healing gel polymer electrolyte (SHGPE) based on N‐isopropylacrylamide (NIPA), N, N‐dimethylacrylamide (DMAA), and ionic liquid is proposed. The formed dynamic and hierarchical hydrogen‐bonding network can not only contribute to outstanding self‐healing ability in SHGPE, but also constrain the corrosion, leakage, and humidity sensitivity of ionic liquid. The hydrogen‐bonding network in SHGPE promotes a stable electrode/electrolyte interface. Therefore, the Al/SHGPE/Al symmetric cell can stably cycle for over 8000 h at 0.5 mA cm −2 , and the Al/SHGPE/Graphite full cell achieves an ultra‐long cycle life of 50 000 cycles at 2 A g −1 . Furthermore, the SHGPE also shows high flexibility and good safety in pouch cells. This study provides a promising strategy for designing durable, flexible, and long cycle life RABs.