Synergistic Electric-Spin-Dipole Modulation for Bidirectional Polysulfide Conversion Toward Reliable Lithium-Sulfur...

Electric, spin, and dipole coupling effects are increasingly employed in lithium-sulfur (Li─S) batteries to suppress the shuttle effect and enhance reaction kinetics. However, the controllable modulation of the electric field, spin states, and dipole interactions and their effects on lithium polysulfides (LiPSs) remains not fully understood, especially the synergies between these factors. Herein, we deliberately incorporates amorphous CoB specifically into Co-CoP heterojunctions to coordinately regulate built-in electric fields (BIEF), spin states, and electrostatic coupling effects. The amorphous CoB phase effectively reduces the BIEF intensity of Co-CoP, facilitating bidirectional LiPSs migration across the heterointerface during the charging/discharging process. The doping of B induces the spin state of transition metal Co toward a low-spin configuration, which leads to increased localization of d-orbital electrons, reduces the d-p energy level gap, and optimizes d-p orbital hybridization between cobalt and sulfur atoms validated by theoretical calculations. Compared to the weak dipole moment in CoP, the uniform alignment of dipoles within CoB generates moderately enhanced electrostatic attraction, which enhances bonding effects with LiPSs and improves adsorption-hybridization performance. This work proposes a multi-dimensional cooperative regulation mechanism (BIEF, spin, and dipole) for enhancing the polysulfide confinement/conversion, which can be extended to other battery systems suffering from shuttle effects.