Electrospun Ti3C2 MXene Fiber‐Decorated Interlayer for Synchronous Sulfur Activation and Lithium Stabilization

Abstract Concurrent regulation of sulfur redox kinetics and lithium deposition homogeneity is a key prerequisite for achieving high‐performance lithium–sulfur (Li–S) batteries. To this end, rational design of dual‐functional interlayers is recognized as a feasible yet promising approach. Herein, few‐layered Ti 3 C 2 MXene flakes are uniformly decorated into the porous carbon nanofiber film via a straightforward electrostatic spinning technique, wherein the Ti 3 C 2 MXene content is fine‐tuned to maximum sulfur utilization and stabilize lithium anode. For one thing, it is revealed by synchrotron radiation X‐ray three‐dimensional nano‐computed tomography that Ti 3 C 2 MXene‐decorated fiber can expedite polysulfide conversion and induce favorable Li 2 S nucleation. For another, small‐angle neutron scattering evidence substantiates that abundant lithiophilic sites are conducive to homogenizing Li‐ion flux and promoting lithium deposition during cycling procedure. As a consequence, Li–S batteries maintain a stable operation at 2.0 C over 1000 cycles with a low‐capacity degeneration rate of 0.057% per cycle, accompanied by a superior areal capacity of 7.5 mAh cm −2 when the sulfur loading is increased to 9.5 mg cm −2 . More encouragingly, the as‐assembled multi‐layer Li–S pouch cell deliver an impressive cell energy density of 342.3 Wh kg −1 with smooth cyclic operation.