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影响因子：13.3

DOI码：10.1002/smll.202400855

发表刊物：Small

关键字：3d orbitals, cobalt, electrocatalysts, lithium-oxygen batteries, coordination

摘要：he transition metal oxides/sulfides are considered promising catalysts due to their abundant resources, facile synthesis, and reasonable electrocatalytic activity. Herein, a significantly improved intrinsic catalytic activity is achieved for constructing a Co-based nanocrystal (Co-S@NC) with the coordination of Co─S, Co─S─C, and Co─Nx─C. The calculational and experimental results demonstrate that the diversified chemical environment of Co-cations induces the transition of 3d orbitals to a high spin-state that exhibits the coexistence of Co2+ with fully occupied dπ orbitals and Co3+ with unpaired electrons in dπ orbitals. The diverse dπ orbitals occupation contributes to an elevated d-band center of Co ions, which accelerates oxygen reduction reaction and oxygen evolution reaction electrocatalytic kinetics of the Co-S@NC nanocrystal. Therefore, the Li–O2 batteries with Co-S@NC as cathode catalyst exhibit 300 cycles at the current density of 500 mA g−1 with a cut-off capacity of 1000 mAh g−1. Moreover, the ultrahigh discharge specific capacity of 34 587 mAh g−1 is obtained at a current density of 1000 mA g−1, corresponding to the energy density 949 Wh kg−1 of a prototype Li–O2 battery. The study on 3d orbital regulation of nanocrystals provides an innovative strategy for bifunctional electrocatalysts toward the practical application of metal–air batteries.

论文类型：期刊论文

论文编号：2400855

是否译文：否

发表时间：2024-01-01

收录刊物：SCI