Synergistic d/p-band regulation of Ni-Co₃Se₄ electrocatalyst for high-performance lithium–sulfur batteries

Synchronously regulating the electronic structures of metal and nonmetal sites offers a promising approach for developing highly active electrocatalysts, yet it has not been applied to the construction of advanced lithium–sulfur battery (LSB) electrocatalysts, and the related optimization mechanisms have not been fully explored. Herein, a highly active LSB electrocatalyst of Ni-Co₃Se₄ with superior performance was developed by synchronously regulating the electronic structures of Co and Se atoms in MOF-derived mixed-valence Co₃Se₄ nanomaterials. The synchronous shift of the d-band center of Co and the p-band center of Se toward the Fermi level, along with the increase in total electron density at the Fermi level, enables Ni-Co₃Se₄ to adsorb sulfur species more efficaciously and catalyze their redox conversion more efficiently. The LSBs incorporating Ni-Co₃Se₄ deliver a high initial discharge capacity (1462 mAh g⁻¹), along with excellent rate performance (4.0C, 743 mAh g⁻¹) and outstanding cycling stability. Even under lean-electrolyte conditions, the batteries with a sulfur loading of 6.77 mg cm⁻² still sustain a discharge capacity of 755 mAh g⁻¹ after 70 cycles. This work demonstrates the significant effectiveness of synchronously regulating the electronic structures of metal and nonmetal sites in optimizing LSB electrocatalysts and reveals the corresponding mechanism.