In Situ Assembly Engineering-Induced 3D MOF-Driven MXene Framework for Highly Stable Na Metal Anodes

Abstract

Sodium metal, with its high theoretical capacity, low redox potential, and cost-effectiveness, presents a promising anode candidate for next-generation high-energy-density batteries. However, the development of Na metal anodes is significantly challenged by issues such as uncontrolled dendrite growth, uncontrolled volume expansion, and associated safety concerns. Designing and developing advanced materials to enhance the conductivity of sodium metal anodes and promote uniform sodium ion deposition are of urgent importance. Herein, a MXene-based hybrid material was developed by integrating MOF-derived Zn, Co, N, and C dopants with Ti₃C₂T_x MXene to serve as a hosting substrate for the Na metal anode. The MXene provided a conductive framework, while the MOF-derived dopants introduced sodiophilic sites, promoting uniform Na deposition and mitigating volume expansion. The optimized material demonstrated an average Coulombic efficiency of 99.99% over 3000 cycles and stable cycling for over 5000 h in symmetrical cells and maintained over 80% capacity retention at 3 C after 500 cycles in full-cell tests, highlighting its potential as a robust Na metal anode material.