First Principles Insights Into Electronic, Adsorptive, and Diffusive Properties of Goldene for Advanced Energy Storage Applications

Two‐dimensional (2D) goldene has recently emerged as an intriguing metallic nanosheet, yet its electrochemical potential remains largely unexplored. Using comprehensive density functional theory (DFT) calculations, the present work demonstrates that goldene exhibits exceptional promise as a high‐performance electrode material for lithium‐ion batteries and supercapacitors. Pristine goldene shows excellent structural stability with a favorable cohesive energy of −2.63 eV atom −1 . Lithium preferentially adsorbs at the hollow site with moderate binding (−0.92 eV), ensuring reversible storage without clustering while preserving metallic conductivity. Goldene displays an ultralow Li‐ion migration barrier of only 0.046 eV, which is further reduced to 0.032 eV when in contact with ethylene carbonate medium, enabling rapid ion transport. At full lithiation, the system maintains metallic behavior and delivers a specific capacity of 174 mAh g − 1 and a volumetric capacity of 1.17 Ah cm − 3 finding application as electrode materials. AIMD simulations confirm robust thermal stability and Li + diffusivity of 3.00 × 10 −10 m 2 s −1 at 300 K. Moreover, goldene exhibits outstanding quantum capacitance, reaching 832.21 µF cm − 2 , surpassing graphene and several reported 2D materials. These results establish goldene as a versatile and highly promising electrode for next‐generation energy storage devices.