Metal-phase molybdenum sulfide (1T-MOS2) is an ideal electrode material for sodium-ion batteries (SIBS) due to its abundant active centers, metal conductivity and high theoretical capacity. However, the thermodynamic instability of 1T-MOS2 under natural conditions makes it difficult to synthesize directly, which seriously hinders its further application.
Figure 1Demonstration of phase transition mechanism
Mai Liqiang of Wuhan University of Technology and Sun Ruimin of China University of GeosciencesElectron modulation and phosphate radical stabilization strategies were used to construct stable 1T-rich molybdenum disulfide (1T-P-MOS2). It was found that the intercalation of the PO43 group into MOS2 by a simple one-step synthesis process increased the layer spacing and improved the insertion and expulsion kinetics of Na+. Density functional theory (DFT) calculations and experiments show that Po43 can donate some electrons to Mo, which will lead to the recombination of Mo4D orbitals, resulting in the spontaneous phase transition of MoS2 from 2h phase to 1t phase, thereby increasing the conductivity of MoS2.
Figure 2Sodium storage properties and kinetics studies.
In addition, 1t-p-mos2 exhibited a higher performance than the original 2h-mos2 (0.).75 EV) has a much lower NA+ migration barrier (0.11ev）。As a result, the stable 1T-P-MOS2 exhibits superior sodium storage performance with a high discharge capacity (636.).2 mAh g 1), ultra-fast charging capability (up to 277 at 40 A g 1).1 mAh g 1, discharged in 25 seconds of charging) and excellent cycling performance (up to 1 mAh after 300 cycles at 1 A g 4989 mah g–1）。Overall, this work provides a feasible technical solution and provides an in-depth analysis of the mechanism of metal sulfide electrode tuning.
Figure 3Study of sodium storage mechanism.
electron modulated and phosphate radical stabilized 1t-rich mos2 for ultra-fast-charged sodium ion storage. advanced energy materials 2023. doi: 10.1002/aenm.202303464