Interlayer-Expanded MoS 2 Nanoflowers Vertically Aligned on MXene@Dual-Phased TiO 2 as High-Performance Anode for Sodium-Ion Batteries.

As a promising energy-storage and conversion anode material for high-power sodium-ion batteries operated at room temperature, the practical application of layered molybdenum disulfide (MoS 2 ) is hindered by volumetric expansion during cycling. To address this issue, a rational design of MoS 2 with enlarged lattice spacing aligned vertically on hierarchically porous Ti 3 C 2 T x MXene nanosheets with partially oxidized rutile and anatase dual-phased TiO 2 (MoS 2 @MXene@D-TiO 2 ) composites via one-step hydrothermal method without following anneal process is reported. This unique "plane-to-surface" structure accomplishes hindering MoS 2 from aggregating and restacking, enabling sufficient electrode/electrolyte interaction simultaneously. Meanwhile, the heterogeneous structure among dual-phased TiO 2 , MoS 2 , and MXene could constitute a built-in electric field, promoting high Na + transportation. As a result, the as-constructed 3D MoS 2 @MXene@D-TiO 2 heterostructure delivers admirable high-rate reversible capacity (359.6 mAh g -1 up to 5 A g -1 ) at room temperature, excellent cycling stability (about 200 mAh g -1 ) at a low temperature of -30 °C, and superior electrochemical performance in Na + full batteries by coupling with a Na 3 V 2 (PO 4 ) 3 cathode. This ingenious design is clean and facile to inspire the potential of advanced low-dimensional heterogeneous structure electrode materials in the application of high-performance sodium-ion batteries.