Tailoring the d-Band Center over Isomorphism Pyrite Catalyst for Optimized Intrinsic Affinity to Intermediates in Lithium–Oxygen Batteries

摘要

Rechargeable lithium–oxygen batteries (LOBs) are regarded as one ofthe most promising candidates for the next generation of energy storagedevices. Nevertheless, the lack of understanding of the relationships betweenstructure, property, and performance of catalysts limits the rational developmentof efficient cathode catalysts, and therefore, hinders the commercialapplication of LOBs. Herein, a d-band center regulation strategy is proposedto construct an isomorphism composite of NiS_2-CoS_2@nitrogendopedcarbon (NiS_2-CoS_2@NC) as an advanced cathode catalyst forboosting the electrocatalytic activities of LOBs. Density functional theorycalculations reveal that the introduction of Ni atoms not only redistributesthe internal charges on the isomorphism structure but also modulates theadsorption capacities of the intermediates by tuning the d-band center, thuspromoting oxygen reduction reaction/oxygen evolution reaction kineticsand reducing the reaction overpotentials. As expected, NiS_2-CoS_2@NCcatalyzed LOBs present superior electrochemical performance includinglarge initial discharge/charge specific capacity of 14 551/13 563 mAh g?1, anultralong cycle life over 490 cycles at a current density of 500 mA g?1, andexcellent rate performance. The insight into the regulation of the adsorptioncapacity of the catalyst by tailoring its d-band center facilitates the rationalconstruction of efficient electrocatalysts for LOBs and other electrocatalyticsystems.