Fast‐Charging MXene/TiN‐Confined In<sub>2</sub>Se<sub>3</sub> Anode with Dual Hydrogen‐Bonding Synergy for High‐Capacity Ammonium‐Ion Storage
Ayesha Irfan, Inaam Ullah, Mai Li, Xiang Peng, Salamat Ali, Muhammad Zubair Nawaz, Ping Zhong, Renchao Che
Abstract
Abstract Aqueous ammonium‐ion (NH 4 + ) based hybrid pseudocapacitors (NH‐HPCs) integrate sustainability and cost‐effectiveness, yet their cycling stability is critically challenged by sluggish NH 4 + transport, particularly in MXene‐based anodes. Herein, NH 3 ‐induced N‐functionalization fabricates a MXene/TiN conductive substrate, enabling confined rotary hydrothermal growth of indium selenide (In 2 Se 3 ) nanoparticles into an In 2 Se 3 @MXene/TiN heterostructure. Directional Ti─N bonds suppress MXene stacking and In 2 Se 3 agglomeration while synergizing charge‐redistribution‐induced lattice strain with hierarchical 2–5 nm pore channels, enabling ultrafast NH 4 + migration. Density functional theory (DFT) calculations confirm electron‐deficient Ti sites and dual Se···H─N/Ti─N···H hydrogen bonds enhance NH 4 + adsorption, where intensified charge polarization and optimized orbital hybridization boost ion storage kinetics and structural stability. The heterostructure anode delivers 1776.1 F g −1 at 1 A g −1 with 98.84% capacitance retention over 6000 cycles. In full‐cell configuration (In 2 Se 3 @MXene/TiN//AC), the NH‐HPC achieves 85.45 Wh kg −1 at 800 W kg −1 —powering a commercial mini‐fan for >4 min after 30 s charging. A modular pouch‐cell version reaches 98.2 Wh kg −1 (800 W kg −1 ), demonstrating exceptional stability during bending/flame tests while operating light emitting diodes array (LEDs). This work highlights interfacial charge synergy in confined heterostructures for unprecedented NH 4 + storage capacity and stability, advancing high‐performance ammonium‐ion energy storage.