Au quantum-dots induced electron-deficient pouch in Au-Ti polarized hosting interface for high-capacity lithium-ion batteries

Abstract We report a novel Au-Ti₃C₂T x -C (Au-TC) hybrid nanocomposite anode, synthesized through interfacial coordination and structural modulation. The gold quantum dots (Au QDs) are selectively anchored with Ti₃C₂Tₓ MXene via electrostatic force. Driven by the effective work function (ϕ eff ) of Au QDs, a polarized hosting interface (PHI) is formed, promoting electron transfer from Au to Ti₃C₂Tₓ and inducing interfacial charge redistribution, lattice distortion, and stabilization of electron-deficient nanoscopic pouches. Our experimental results and density functional theory (DFT) calculations also confirm that the PHI significantly enhanced Li⁺ adsorption by inducing electron-deficient pouches. These pouches serve as efficient Li⁺ hosting sites during intercalation. The Au QDs also induced lattice distortions, which generated defects, including twin boundaries and junction points in Ti₃C₂Tₓ, that enhanced Li⁺ intercalation. The long cycling test demonstrates that Au-TC anode 465 mAh g − ¹ outperforms 20.9% and 113.6% higher capacity in comparison to Ti₃C₂Tₓ-C and pure carbon (initial Coulombic efficiency of 73%) and excellent cycling stability at 0.1 A g⁻¹ current density. Furthermore, the Au-TC anode exhibits a low charge transfer resistance of 24 Ω and a superior lithium-ion diffusion coefficient of 4.72 × 10⁻¹¹ cm²/s. These results confirm Au-TC as a high-capacity and fast charge rate anode material for next-generation lithium-ion batteries.