Synergistically Accelerating Adsorption‐Electrocataysis of Sulfur Species via Interfacial Built‐In Electric Field of SnS₂‐MXene Mott–Schottky Heterojunction in Li‐S Batteries

Abstract

sulfur) and gravimetric energy density (≈2,600 Wh kg −1 ). Nevertheless, there are still a lot of obstacles on the road of commercialization and practical development of LSBs. These obstacles mainly include: 1) The large volume expansion (≈80%), caused by the complex electrochemical reaction process, would damage the electrode structure and shorten their lifespan;2) The poor conductivities of active sulfur (5 × 10 −30 S cm −1 ) and its reaction product of Li 2 S (10 −13 S m −1 ) generate slow electrochemical reaction and large electrochemical polarization; 3) The most notoriously lithium polysulfides (LiPSs) shuttling seriously decreases the utilization rate of sulfur and the cycle life of LSBs. [5][6][7] On the basis of previous studies, the complex electrochemical discharge/charge reaction processes in LSBs always undergo a multiphase transformation of sulfur species with multistep charge transfer (S

A flower‐like VO2(B)/V2CTx heterojunction as high kinetic rechargeable anode for sodium‐ion batteries

“…According to density of states (DOS) shown in Figure 6A,B, the VO exhibited semiconductor behavior with a narrow bandgap of 0.53 eV, while the VC showed a typical metallic characteristic without obvious bandgap. Hence, at the heterojunction interface, electrons will spontaneously transfer from VC to VO until their Fermi levels reach thermodynamic equilibrium, resulting in higher electron density near the Fermi level at the VO@VC heterojunction interface (Figure 6C) compared to that of bare VO 29 . The differential charge density of VO@VC heterostructure can further prove this conclusion.…”

“…Hence, at the heterojunction interface, electrons will spontaneously transfer from VC to VO until their Fermi levels reach thermodynamic equilibrium, resulting in higher electron density near the Fermi level at the VO@VC heterojunction interface (Figure 6C) compared to that of bare VO. 29 The differential charge density of VO@VC heterostructure can further prove this conclusion. As shown in Figure 6D, the charge density at the VO@VC heterojunction interface exhibits a significant charge transfer, indicating the strong interaction between VO and VC.…”

Interfacial Engineering of Ru Nanocluster-Modified TiO2 Nanotube-Assisted Regulation of Lithium Polysulfide Reactions

“…Surprisingly, TiO 2 −Ru not only inherited the LiPSs affinity of TiO 2 but also showed stronger trapping performance, which might be attributed to the internal strong electric field formed by its heterogeneous interface, and the electron redistribution caused more charge transfer of LiPSs on TiO 2 −Ru. 23,24 XPS further analyzed the electronic interaction of LiPSs upon contact with TiO 2 −Ru (Figure 2d). For Ti 2p orbital, the two predominant characteristic peaks at ∼458.3 and ∼464.0 eV were attributed to Ti 2p 3/2 and Ti 2p 1/2 signals by spin− orbit splitting, indicating Ti 4+ in the Ti−O bond.…”

“…Different from the van der Waals force of carbon materials, the adsorption of LiPSs by TiO 2 -based materials was due to chemical interaction. Surprisingly, TiO 2 –Ru not only inherited the LiPSs affinity of TiO 2 but also showed stronger trapping performance, which might be attributed to the internal strong electric field formed by its heterogeneous interface, and the electron redistribution caused more charge transfer of LiPSs on TiO 2 –Ru. , …”

A Separator with Double Coatings of Li4Ti5O12and Conductive Carbon for Li‐S Battery of Good Electrochemical Performance

“…In addition, the advantages of sulfur, which has low cost, is easily available, and environmentally friendly, have also attracted wide attentions. [5][6][7][8] However, The 'shuttle effect' and lithium anode corrosion have always restricted the development of Li-S batteries. During the charging and discharging process, the soluble lithium polysulfides (Li 2 S x , 2 < x ≤ 8) are formed and dissolved in the electrolyte, resulting in the loss of active sulfur and corrosion of lithium anodes, which leads to the sharp capacity decline and poor safety performance.…”