Fast Ion Transport Interphase Integrated with Space Confinement Enabling High‐Rate and Long‐Lifespan Na Metal Batteries

Abstract The practical application of sodium (Na) metal anode has been seriously hindered by the uncontrolled Na dendrite growth and severe volume expansion inducing short battery lifespan and safety concerns. Here, highly sodiophilic and ultrafine ZnS‐modified carbon fibers have been rationally constructed as a scaffold to obviate these drawbacks. The in situ generated Na₂S‐reinforced fast ion transport interphase and the effective space confinement synergistically facilitate the fast sodium ion interfacial transfer and the homogeneous and dendrite‐free Na deposition, thus enabling high‐rate and dendrite‐free Na metal anode. The modified Na metal demonstrates ultrahigh rate capability (15 mA cm⁻²) and ultralong cycling life (5300 cycles). Moreover, the Na|Na₃V₂(PO₄)₃ (NVP) cell delivers ultrahigh rate capability (80 C) and extraordinarily ultralong lifespan cycling durability (2980 cycles). The Na|NVP pouch cell also exhibits an extraordinarily ultralong‐term cycle life of over 1070 cycles with an extremely low capacity decay rate of 0.0088% per cycle at 10 C. This work provides a facile and efficient strategy to propel the Na metal anode towards practicability.