A Nanostructured Phenazine‐Based Conjugated Microporous Polymer Hybrid Anode Boosts Power and Practicability of Organic‐Manganese Hydronium‐Ion Batteries

Abstract Organic‐manganese hydronium‐ion batteries are gaining attention for their safety, sustainability, and high rate capabilities. However, their electrochemical performance faces challenges due to organic active‐materials’ inferior properties, including low conductivity and solubility, and limited content (<60 wt %) and loading (<2 mg cm⁻²) in the anode. To address this, we developed a high‐performance battery using a phenazine‐based conjugated microporous polymer hybrid anode (IEP‐27‐SR), utilizing hydronium‐ion coordination/un‐coordination chemistry. The IEP‐27‐SR anode features enhanced structural characteristics, such as a high BET specific surface area, mixed micro‐/mesoporosity, nanostructurization, and hybridization, enabling rapid hydronium‐ion mobility. The resulting IEP‐27‐SR//MnO₂@GF full‐cell demonstrates high capacity (101 mAh g⁻¹ at 2 C), excellent rate performance (41 mAh g⁻¹ at 100 C), ultrafast‐charging capability (80 % charged in 18 seconds), and impressive cycling stability with 83 % capacity retention over 20400 cycles at 30 C with a regular polymer mass loading of 2 mg cm⁻², despite its high content (80 wt %) in the anode. Moreover, it shows operability at low temperatures (63 mAh g⁻¹ at −40 °C). Most importantly, the full‐cell with a high‐mass‐loading polymer anode (30 mg cm⁻²) achieves practically relevant areal capacity (3.4 mAh cm⁻² at 4 mA cm⁻²) and sustains 2 mAh cm⁻² under an extremely high areal current (50 mA cm⁻²). This breakthrough highlights the progress of organic hydronium‐ion batteries, representing progress toward practical, sustainable energy storage solutions.