Accelerating Charge-Transfer Kinetics via Triggering Electron Spin Polarization in Open-Hollow MoS₂ Nanospheres for Ultrafast Lithium Storage.

Abstract

The development of ultrafast-charging MoS₂ anodes is fundamentally constrained by sluggish charge-transfer kinetics. This study addresses this limitation by triggering electron spin polarization through atomic-scale Co doping within open-hollow MoS₂ nanospheres. Structurally, the open-hollow design minimizes ion diffusion distances and accommodates volume changes of MoS₂, providing a robust foundation for rapid ion flux. Electronically, Co incorporation enhances S 3p-Mo 4d-Co 3d orbital hybridization, triggering a marked electron spin polarization that reduces kinetic barriers for insertion and conversion reactions. Post-conversion stage, in situ generated metallic Co nanoparticles (Co⁰) act as dynamic mediators for spin-polarized electron transfer. Specifically, the injection of spin-polarized electrons into Co° creates a spin-polarized surface capacitance, boosting charge storage at the Co⁰/Li₂S interfaces. Conversely, the release of these electrons promotes a Co⁰-catalyzed construction of solid electrolyte interphase, prioritizing conductive LiF species while suppressing Li₂CO₃, facilitating ion transport at the electrode-electrolyte interfaces. Consequently, the MoS₂-based anode exhibits an impressive ultrafast-charging capability of 30 C (1044.1 mAh g^-1) and maintains stability over 10 000 cycles at 15 C with a final capacity of 874.7 mAh g^-1. This work demonstrates that triggering electron spin polarization represents a transformative approach to overcoming kinetic barriers in next-generation ultrafast-charging batteries.