ABSTRACT Multivalent transition metal sulfides (TMSs) with rapid electron transport capability and high redox activity hold significant research potential as sodium‐ion batteries (SIBs) anodes. Herein, layered TMSs Cu 2 MS 4 (M = Mo, W) were synthesized via a solvothermal method to compare their sodium storage properties. Compared to the relatively limited valence state changes in Cu 2 WS 4 , Cu 2 MoS 4 exhibits richer multivalent redox activity involving the synergistic interaction of Mo 4+ /Mo 5+ /Mo 6+ and Cu 2+ /Cu + . The material's inherent rich valence states enhance Na + adsorption by regulating the upward shift of the Mo d ‐band center in Cu 2 MoS 4 and optimizing the related electronic interactions, while also effectively improving redox reversibility and reactivity via synergistic multielectron pathways. Therefore, Cu 2 MoS 4 maintains an exceptional capacity retention of 531.2 mA h g −1 after 5500 cycles at 20 A g −1 , and retains 284.6 mA h g −1 even at an ultrahigh rate of 50 A g −1 , demonstrating outstanding rate capability. Theoretical calculations attribute these advantages to enhanced electron localization (post Na + incorporation), higher conductivity, lower ion diffusion barriers, and improved reaction reversibility versus Cu 2 WS 4 . This study establishes multivalent TMSs as a promising strategy for advanced sodium storage, facilitated by their enhanced electron localization effect.
Lu et al. (Tue,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: