Silver-Atom Modulation of Ti Vacancies in MXene Enables Uniform Spherical Lithium Deposition

Abstract

Effective management of lithium (Li) metal nucleation and growth is critical for its practical application, yet a limited understanding of Li metal anode morphology has impeded progress. This study advances the comprehension of dense spherical Li deposition by linking atomic charge distributions to macroscopic phenomena. By introducing silver (Ag) single atoms into titanium (Ti) vacancies in MXene, we form a unique Ag–C composite that modulates charge distribution, thereby facilitating uniform, spherical Li deposition across the surface. This approach minimizes Ag consumption to below 1 wt % while achieving Li metal deposition capacities exceeding 40 mAh cm^–2. Moreover, full cells incorporating MXene-AgSAs@Li anodes paired with LiFePO₄ or sulfur cathodes exhibit a significantly enhanced cycling performance and high rate capabilities. These findings provide novel insights into the role of charge partitioning in Li metal deposition and the formation of dense, spherical Li arrays.