Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or exce...Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or excessive Vo reduces polysulfide adsorption and lowers catalytic stability.Herein,a novel“heteroatoms synergistic anchoring vacancies”strategy is proposed to address the trade-off between high activity and stability.Phosphorus-doped CoSe_(2)with remained rich selenium vacancies(P-CS-Vo-0.5)was synthesized by producing abundant selenium Vo followed by controlled P atom doping.Atomic-scale microstructure analysis elucidated a dynamic process of surface vacancy generation and the subsequent partial occupation of these vacancies by P atoms.Density functional theory simulations and in situ Raman tests revealed that the Se vacancies provide highly active catalytic sites,accelerating polysulfide conversion,while P incorporation effectively reduces the surface energy of Se vacancies and suppresses their inward migration,enhancing structural robustness.The battery with the optimal P-CS-Vo-0.5 separator delivers an initial discharge capacity of 1306.7 mAh g^(-1)at 0.2C,and maintain 5.04 mAh cm^(-2)at a high sulfur loading(5.7 mg cm^(-2),5.0μL mg^(-1)),achieving 95.1%capacity retention after 80 cycles.This strategy of modifying local atomic environments offers a new route to designing highly active and stable catalysts.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1602700 and 2022YFB2502104)the National Natural Science Foundation of China(22375089)the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(BE2022332).
文摘Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or excessive Vo reduces polysulfide adsorption and lowers catalytic stability.Herein,a novel“heteroatoms synergistic anchoring vacancies”strategy is proposed to address the trade-off between high activity and stability.Phosphorus-doped CoSe_(2)with remained rich selenium vacancies(P-CS-Vo-0.5)was synthesized by producing abundant selenium Vo followed by controlled P atom doping.Atomic-scale microstructure analysis elucidated a dynamic process of surface vacancy generation and the subsequent partial occupation of these vacancies by P atoms.Density functional theory simulations and in situ Raman tests revealed that the Se vacancies provide highly active catalytic sites,accelerating polysulfide conversion,while P incorporation effectively reduces the surface energy of Se vacancies and suppresses their inward migration,enhancing structural robustness.The battery with the optimal P-CS-Vo-0.5 separator delivers an initial discharge capacity of 1306.7 mAh g^(-1)at 0.2C,and maintain 5.04 mAh cm^(-2)at a high sulfur loading(5.7 mg cm^(-2),5.0μL mg^(-1)),achieving 95.1%capacity retention after 80 cycles.This strategy of modifying local atomic environments offers a new route to designing highly active and stable catalysts.
