MXene‐Integrated Perylene Anode with Ultra‐Stable and Fast Ammonium‐Ion Storage for Aqueous Micro Batteries

The aqueous micro batteries (AMBs) are expected to be one of the most promising micro energy storage devices for its safe operation and cost-effectiveness. However, the performance of the AMBs is not satisfactory, which is attributed to strong interaction between metal ions and the electrode materials. Here, the first AMBs are developed with NH₄ ⁺ as charge carrier. More importantly, to solve the low conductivity and the dissolution during the NH₄ ⁺ intercalation/extraction problem of perylene material represented by perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), the Ti₃ C₂ T_x MXene with high conductivity and polar surface terminals is introduced as a conductive skeleton (PTCDA/Ti₃ C₂ T_x MXene). Benefitting from this, the PTCDA/Ti₃ C₂ T_x MXene electrodes exhibit ultra-high cycle life and rate capability (74.31% after 10 000 galvanostatic chargedischarge (GCD) cycles, and 91.67 mAh g^-1 at 15.0 A g^-1 , i.e., capacity retention of 45.2% for a 30-fold increase in current density). More significantly, the AMBs with NH₄ ⁺ as charge carrier and PTCDA/Ti₃ C₂ T_x MXene anode provide excellent energy density and power density, cycle life, and flexibility. This work will provide strategy for the development of NH₄ ⁺ storage materials and the design of AMBs.