Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity,but infinite volume change and dendritic growth during Li electrodeposition have pre...Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity,but infinite volume change and dendritic growth during Li electrodeposition have prevented its practical applications.Both physical morphology confinement and chemical adsorption/diffusion regulation are two crucial approaches to designing lithiophilic materials to alleviate dendrite of Li metal anode.However,their roles in suppressing dendrite growth for long-life Li anode are not fully understood yet.Herein,three different Ni-based nanosheet arrays(NiO-NS,Ni_(3)N-NS,and Ni_(5)P_(4)-NS)on carbon cloth as proof-of-concept lithiophilic frame-works are proposed for Li metal anodes.The two-dimensional nanoarray is more promising to facilitate uniform Li^(+)flow and electric field.Compared with the NiO-NS and the Ni_(5)P_(4)-NS,the Ni_(3)N-NS on carbon cloth after reacting with molten Li(Li-Ni/Li_(3)N-NS@CC)can afford the strongest adsorption to Li+and the most rapid Li+diffusion path.Therefore,the Li-Ni/Li_(3)N-NS@CC electrode realizes the lowest overpotential and the most excellent electrochemical performance(60 mA cm^(−2)and 60 mAh cm^(−2)for 1000 h).Furthermore,a remarkable full battery(LiFePO_(4)||Li-Ni/Li_(3)N-NS@CC)reaches 300 cycles at 2C.This research provides valuable insight into designing dendrite-free alkali metal batteries.展开更多
Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which ...Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.展开更多
基金supported by the National Key R&D Research Program of China the National Key Research Program(No.2018YFB0905400)the National Natural Science Foundation of China(Nos.51925207,U1910210,51872277,52002083,52102322 and 22109011)+5 种基金National Synchrotron Radiation Laboratory(KY2060000173)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA21000000)the Fundamental Research Funds for the Central Universities(Wk2060140026,Wk2400000004,Wk20720220010)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant.YLU-DNL Fund 2021002)the National Postdoctoral Program for Innovative Talents(BX20200047)the China Postdoctoral Science Foundation(2021M690380).
文摘Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity,but infinite volume change and dendritic growth during Li electrodeposition have prevented its practical applications.Both physical morphology confinement and chemical adsorption/diffusion regulation are two crucial approaches to designing lithiophilic materials to alleviate dendrite of Li metal anode.However,their roles in suppressing dendrite growth for long-life Li anode are not fully understood yet.Herein,three different Ni-based nanosheet arrays(NiO-NS,Ni_(3)N-NS,and Ni_(5)P_(4)-NS)on carbon cloth as proof-of-concept lithiophilic frame-works are proposed for Li metal anodes.The two-dimensional nanoarray is more promising to facilitate uniform Li^(+)flow and electric field.Compared with the NiO-NS and the Ni_(5)P_(4)-NS,the Ni_(3)N-NS on carbon cloth after reacting with molten Li(Li-Ni/Li_(3)N-NS@CC)can afford the strongest adsorption to Li+and the most rapid Li+diffusion path.Therefore,the Li-Ni/Li_(3)N-NS@CC electrode realizes the lowest overpotential and the most excellent electrochemical performance(60 mA cm^(−2)and 60 mAh cm^(−2)for 1000 h).Furthermore,a remarkable full battery(LiFePO_(4)||Li-Ni/Li_(3)N-NS@CC)reaches 300 cycles at 2C.This research provides valuable insight into designing dendrite-free alkali metal batteries.
基金This work was supported by the Natural Science Foundation of China(22125902,21975243,U2032202,and U1932201)the National Program for Support of Topnotch Young Professionals,the DNL Cooperation Fund,CAS(DNL202020)+2 种基金the Anhui Science Fund for Distinguished Young Scholars(2208085J15)the National Key R&D Program of China(2022YFA1504101)Users with Excellence Program of Hefei Science Center CAS(2021HSC-UE002).
文摘Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.
