Carbon-supported single-atom catalysts(C-SACs)have been demonstrated as a strategy to promote the reversible conversion reaction of metal sulfide anodes in sodium-ion batteries(SIBs).However,the design principle of pr...Carbon-supported single-atom catalysts(C-SACs)have been demonstrated as a strategy to promote the reversible conversion reaction of metal sulfide anodes in sodium-ion batteries(SIBs).However,the design principle of promising C-SACs remains lacking for obtaining highly reversible metal sulfide anodes.We designed a phosphorus-doped carbon-supported single-atom Mn catalyst(PC-SAMn)with an asymmetrical dual active center.The sulfiphilic Mn and sodiophilic P active centers adsorb discharged Na 2S through Mn-S d-p and P-Na s-p orbital hybridizations.The asymmetrical dual active center induced the asymmetrical adsorption configuration of Na 2S,which efficiently weakened Na-S bond strength and facilitated the decomposition of Na 2S during charging.As a result,the designed catalyst enables typical MoS_(2) with a record-high compositional reversible degree of 89.61%and a low capacity decay ratio of only 0.18%per 100 cycles during 2000 cycles.The research establishes the“orbital hybridization-molecular structure-catalytic activity”relationship for guiding the design of highly reversible conversion-type materials.展开更多
The two major limitations in the application of SnO_2 for lithium?ion battery(LIB) anodes are the large volume variations of SnO_2 during repeated lithiation/delithiation processes and a large irreversible capacity lo...The two major limitations in the application of SnO_2 for lithium?ion battery(LIB) anodes are the large volume variations of SnO_2 during repeated lithiation/delithiation processes and a large irreversible capacity loss during the first cycle, which can lead to a rapid capacity fade and unsatisfactory initial Coulombic e ciency(ICE). To overcome these limitations, we developed composites of ultrafine SnO_2 nanoparticles and in situ formed Co(CoSn) nanocrystals embedded in an N?doped carbon matrix using a Co?based metal–organic framework(ZIF?67). The formed Co additives and structural advantages of the carbon?confined SnO_2/Co nanocomposite e ectively inhibited Sn coarsening in the lithiated SnO_2 and mitigated its structural degradation while facilitating fast electronic transport and facile ionic di usion. As a result, the electrodes demonstrated high ICE (82.2%), outstanding rate capability(～ 800 mAh g^(-1) at a high current density of 5 A g^(-1)), and long?term cycling stability(～ 760 mAh g^(-1) after 400 cycles at a current density of 0.5 A g^(-1)). This study will be helpful in developing high?performance Si(Sn)?based oxide, Sn/Sb?based sulfide, or selenide electrodes for LIBs. In addition, some metal organic frameworks similar to ZIF?67 can also be used as composite templates.展开更多
基金supported by the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001)the Natural Science Foundation of Tianjin City(23JCZDJC01110)+5 种基金the National Natural Science Foundation of China(51972225 and 52202281)the Tianjin University Science and Technology Innovation Leading Talent Training Programthe Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0538)the Natural Science Basic Research Program of Shaanxi(2024JC-YBQN-0073)the Young Talent Fund of Association for Science and Technology in Shaanxi(20230101)the Innovation Capability Support Program of Shaanxi-Science and Technology Innovation Team Project(2025RS-CXTD-024)。
文摘Carbon-supported single-atom catalysts(C-SACs)have been demonstrated as a strategy to promote the reversible conversion reaction of metal sulfide anodes in sodium-ion batteries(SIBs).However,the design principle of promising C-SACs remains lacking for obtaining highly reversible metal sulfide anodes.We designed a phosphorus-doped carbon-supported single-atom Mn catalyst(PC-SAMn)with an asymmetrical dual active center.The sulfiphilic Mn and sodiophilic P active centers adsorb discharged Na 2S through Mn-S d-p and P-Na s-p orbital hybridizations.The asymmetrical dual active center induced the asymmetrical adsorption configuration of Na 2S,which efficiently weakened Na-S bond strength and facilitated the decomposition of Na 2S during charging.As a result,the designed catalyst enables typical MoS_(2) with a record-high compositional reversible degree of 89.61%and a low capacity decay ratio of only 0.18%per 100 cycles during 2000 cycles.The research establishes the“orbital hybridization-molecular structure-catalytic activity”relationship for guiding the design of highly reversible conversion-type materials.
基金supported by the National Key R&D Program of China (No. 2016YFA0202602)the National Natural Science Foundation of China (Grant Nos. 21503178 and 21703185)supported by XMU Undergraduate Innovation and Entrepreneurship Training Programs (Grants No. 2017X0695 for Huijiao Yang and Xiaocong Tang)
文摘The two major limitations in the application of SnO_2 for lithium?ion battery(LIB) anodes are the large volume variations of SnO_2 during repeated lithiation/delithiation processes and a large irreversible capacity loss during the first cycle, which can lead to a rapid capacity fade and unsatisfactory initial Coulombic e ciency(ICE). To overcome these limitations, we developed composites of ultrafine SnO_2 nanoparticles and in situ formed Co(CoSn) nanocrystals embedded in an N?doped carbon matrix using a Co?based metal–organic framework(ZIF?67). The formed Co additives and structural advantages of the carbon?confined SnO_2/Co nanocomposite e ectively inhibited Sn coarsening in the lithiated SnO_2 and mitigated its structural degradation while facilitating fast electronic transport and facile ionic di usion. As a result, the electrodes demonstrated high ICE (82.2%), outstanding rate capability(～ 800 mAh g^(-1) at a high current density of 5 A g^(-1)), and long?term cycling stability(～ 760 mAh g^(-1) after 400 cycles at a current density of 0.5 A g^(-1)). This study will be helpful in developing high?performance Si(Sn)?based oxide, Sn/Sb?based sulfide, or selenide electrodes for LIBs. In addition, some metal organic frameworks similar to ZIF?67 can also be used as composite templates.
