Abstract
Based on multielectron conversion reactions, layered transition metal dichalcogenides are considered promising electrode materials for sodium-ion batteries, but suffer from poor cycling performance and rate capability due to their low intrinsic conductivity and severe volume variations. Here, interlayer-expanded MoSe(2)/phosphorus-doped carbon hybrid nanospheres coated by anatase TiO(2) (denoted as MoSe(2)/P-C@TiO(2)) are prepared by a facile hydrolysis reaction, in which TiO(2) coating polypyrrole-phosphomolybdic acid is utilized as a novel precursor followed by a selenization process. Benefiting from synergistic effects of MoSe(2), phosphorus-doped carbon, and TiO(2), the hybrid nanospheres manifest unprecedented cycling stability and ultrafast pseudocapacitive sodium storage capability. The MoSe(2)/P-C@TiO(2) delivers decent reversible capacities of 214 mAh g(-1) at 5.0 A g(-1) for 8000 cycles, 154 mAh g(-1) at 10.0 A g(-1) for 10000 cycles, and an exceptional rate capability up to 20.0 A g(-1) with a capacity of ≈175 mAh g(-1) in a voltage range of 0.5-3.0 V. Coupled with a Na(3)V(2)(PO(4))(3)@C cathode, a full cell successfully confirms a reversible capacity of 242.2 mAh g(-1) at 0.5 A g(-1) for 100 cycles with a coulombic efficiency over 99%.