Phosphorus‐Regulated Te‐Vacancy‐Localized Re ₂ Te ₅ Anchored on TiN/MXene as High‐Energy Anode for all‐Solid‐State Lithium‐Ion Storage

Abstract Conventional liquid‐electrolyte supercapacitors face leakage risks and low energy density, restricting their viability in portable electronics. Herein, a solid‐state supercapacitor system overcomes these challenges via a P‐A/C‐Re 2 Te 5 @TiN/MXene anode paired with a SiO 2 ‐optimized PVA/LiCl electrolyte. Phosphorus doping induces Te vacancies in Re 2 Te 5 via P‐Re coupling, enabling high‐density Li + adsorption sites and intrinsic conductivity. The N‐functionalized TiN/MXene framework provides a robust conductive network that simultaneously stabilizes P‐A/C‐Re 2 Te 5 through mechanical confinement while enabling efficient charge transfer via its high surface area and strong interfacial coupling. DFT calculations validate metallic behavior, optimal Li + adsorption (−3.3 eV), and rapid charge transfer. The electrode achieves exceptional specific capacitance (1458 F g −1 at 0.3 A g −1 ) with ultralow charge transfer resistance. Integrated into a solid‐state (P‐A/C‐Re 2 Te 5 @TiN/MXene//AC) device with a SiO 2 ‐optimized PVA/LiCl electrolyte, the system delivers breakthrough energy‐power metrics (56.3 Wh kg −1 at 780 W kg −1 in coin cells, powering commercial mini‐fan for >2 min after 10 s charging), while its scalable pouch configuration delivers 84.6 Wh kg −1 with exceptional cycling stability and 120° bending durability. This work demonstrates a flexible and high‐energy storage platform for wearables, merging defect engineering, heterojunction design, and interface optimization to transition from lab‐scale innovation to real‐world applications.