High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unpa...High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unparalleled performance,the relationships between multiple active sites and reaction intermediates are still obscure.Here,enlightened by theoretical screening,we tailor a high-entropy perovskite fluoride(KCoMnNiMgZnF_(3)-HEC)with various active sites to overcome the limitations of conventional catalysts in redox process.The entropy effect modulates the d-band center and d orbital occupancy of active centers,which optimizes the d–p hybridization between catalytic sites and key intermediates,enabling a moderate adsorption of LiO_(2)and thus reinforcing the reaction kinetics.As a result,the Li–O2 battery with KCoMnNiMgZnF_(3)-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability,preceding majority of traditional catalysts reported.These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.展开更多
Doping have been considered as a prominent strategy to stabilize crystal structure of battery materials during the insertion and removal of alkali ions.The instructive knowledge and experience acquired from doping str...Doping have been considered as a prominent strategy to stabilize crystal structure of battery materials during the insertion and removal of alkali ions.The instructive knowledge and experience acquired from doping strategies predominate in cathode materials,but doping principle in anodes remains unclear.Here,we demonstrate that trace element doping enables stable conversion-reaction and ensures structural integrity for potassium ion battery(PIB) anodes.With a synergistic combination of X-ray tomography,structural probes,and charge reconfiguration,we encode the physical origins and structural evolution of electro-chemo-mechanical degradation in PIB anodes.By the multiple ion transport pathways created by the orderly hierarchical pores from "surface to bulk" and the homogeneous charge distribution governed in doped nanodomains,the anisotropic expansion can be significantly relieved with trace isoelectronic element doping into the host lattice,maintaining particle mechanical integrity.Our work presents a close relationship between doping chemistry and mechanical reliability,projecting a new pathway to reengineering electrode materials for next-generation energy storage.展开更多
Monoclinic Li_(2)V_(2)(PO_(4))_(3);is a promising cathode material with complex charge–discharge behavior.Previous structural investigation of this compound mainly focuses on local environments;while the reaction kin...Monoclinic Li_(2)V_(2)(PO_(4))_(3);is a promising cathode material with complex charge–discharge behavior.Previous structural investigation of this compound mainly focuses on local environments;while the reaction kinetics and the driving force of irreversibility of this material remain unclear.To fully understand the above issues,both the equilibrium and the non-equilibrium reaction routes have been systematically investigated in this study.Multiple characterization techniques including X-ray diffraction,variable temperature(spinning rate)and ex/in situ ^(7)Li,^(31)P solid state NMR have been employed to provide comprehensive insights into kinetics,dynamics,framework structure evolution and charge ordering,which is essential to better design and application of lithium transition metal phosphate cathodes.Our results suggest that the kinetics process between the non-equilibrium and the quasi-equilibrium delithiation pathways from Li_(2)V_(2)(PO_(4))_(3);to V_(2)(PO_(4))_(3);is related with a slow relaxation from two-site to one-site delithiation.More importantly,it has been demonstrated that the irreversibility in this system is not solely affected by cation and/or charge ordering/disordering,but mainly driven by framework structure distortion.展开更多
CONSPECTUS:Lithium-ion batteries have been widely applied in portable electronics due to their high energy density(300 Wh kg^(-1)).However,their potential applications in electric vehicles and grid energy storage call...CONSPECTUS:Lithium-ion batteries have been widely applied in portable electronics due to their high energy density(300 Wh kg^(-1)).However,their potential applications in electric vehicles and grid energy storage call for higher energy density toward 500 Wh kg^(-1).Solid-state batteries,employing highly safe electrolytes to replace flammable liquid electrolytes,probably achieve this aim by reviving the metallic lithium anode.However,the sluggish lithium transport across the solid−solid interfaces seriously influences the actual battery electrochemistry in applications.Unlike the relatively complete basic theories of solid−liquid electrochemistry,the electrochemical fundamentals and models in the solid-state batteries are still ambiguous,which cannot give a guideline for optimizing strategies for high battery performance.Therefore,building better batteries for next-generation electrochemical energy storage remains a great challenge.Synchrotron X-ray imaging techniques are currently catching increasing attention due to their natural advantages,which are nondestructiveness,chemically responsiveness,elementally sensitivity,and high penetrability to enable operando investigation of a real battery.Based on the derived nanotomography techniques,it can provide 3D morphological information including thousands of slice morphologies from the bulk to the surface.Combined with X-ray absorption spectroscopy,X-ray imaging can even present chemical and phase mapping information,including the oxidation state,local environment,etc.,with sub-30 nm spatial resolution,which addresses the issues that we only obtain as averaged information in traditional X-ray absorption spectroscopy.Through an operando charging/discharging setup,X-ray imaging enables the study of the correlation between the morphology change and the chemical evolution(mapping)under different states of charge and cycling.In addition,X-ray imaging breaks up the size limit of nanoscale samples for the in-situ transmission electron microscope imaging,which enables a large,thick sample with a broad field of view,truly uncovering the behavior inside a real battery system.展开更多
基金P.G.acknowledges the financial support from the Youth Foundation of Shandong Natural Science Foundation(No.ZR2023OB230)National Natural Science Foundation(No.22309035)Double First-class Discipline Construction Fund Project of Harbin Institute of Technology at Weihai(No.2023SYLHY11).
文摘High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unparalleled performance,the relationships between multiple active sites and reaction intermediates are still obscure.Here,enlightened by theoretical screening,we tailor a high-entropy perovskite fluoride(KCoMnNiMgZnF_(3)-HEC)with various active sites to overcome the limitations of conventional catalysts in redox process.The entropy effect modulates the d-band center and d orbital occupancy of active centers,which optimizes the d–p hybridization between catalytic sites and key intermediates,enabling a moderate adsorption of LiO_(2)and thus reinforcing the reaction kinetics.As a result,the Li–O2 battery with KCoMnNiMgZnF_(3)-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability,preceding majority of traditional catalysts reported.These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.
基金supported by the start-up fund and‘‘Young Scientist Studio”of Harbin Institute of Technology(HIT)the National Natural Science Foundation of China(No.U1932205)+1 种基金the Natural Science Funds of Heilongjiang Province(No.ZD2019B001)the HIT Research Institute(Zhao Yuan)of New Materials and the Intelligent Equipment Technology Co.,Ltd.Scientific and Technological Cooperation and Development Fund(No.2017KJHZ002)。
文摘Doping have been considered as a prominent strategy to stabilize crystal structure of battery materials during the insertion and removal of alkali ions.The instructive knowledge and experience acquired from doping strategies predominate in cathode materials,but doping principle in anodes remains unclear.Here,we demonstrate that trace element doping enables stable conversion-reaction and ensures structural integrity for potassium ion battery(PIB) anodes.With a synergistic combination of X-ray tomography,structural probes,and charge reconfiguration,we encode the physical origins and structural evolution of electro-chemo-mechanical degradation in PIB anodes.By the multiple ion transport pathways created by the orderly hierarchical pores from "surface to bulk" and the homogeneous charge distribution governed in doped nanodomains,the anisotropic expansion can be significantly relieved with trace isoelectronic element doping into the host lattice,maintaining particle mechanical integrity.Our work presents a close relationship between doping chemistry and mechanical reliability,projecting a new pathway to reengineering electrode materials for next-generation energy storage.
基金supported by the National Natural Science Foundation of China(21673065,21403045,21473148)the Public Project of State Key Laboratory for Physical Chemistry of Solid Surface and Department of Chemistry,Xiamen University(201407)。
文摘Monoclinic Li_(2)V_(2)(PO_(4))_(3);is a promising cathode material with complex charge–discharge behavior.Previous structural investigation of this compound mainly focuses on local environments;while the reaction kinetics and the driving force of irreversibility of this material remain unclear.To fully understand the above issues,both the equilibrium and the non-equilibrium reaction routes have been systematically investigated in this study.Multiple characterization techniques including X-ray diffraction,variable temperature(spinning rate)and ex/in situ ^(7)Li,^(31)P solid state NMR have been employed to provide comprehensive insights into kinetics,dynamics,framework structure evolution and charge ordering,which is essential to better design and application of lithium transition metal phosphate cathodes.Our results suggest that the kinetics process between the non-equilibrium and the quasi-equilibrium delithiation pathways from Li_(2)V_(2)(PO_(4))_(3);to V_(2)(PO_(4))_(3);is related with a slow relaxation from two-site to one-site delithiation.More importantly,it has been demonstrated that the irreversibility in this system is not solely affected by cation and/or charge ordering/disordering,but mainly driven by framework structure distortion.
基金This work was supported by HIT“Young Scientist Studio”and the start-up funds from Harbin Institute of Technology,Natural Science Foundation of China(Nos.U193220046 and 21905071)Heilongjiang Touyan Team(No.HITTY-20190033)+1 种基金Natural Science Foundation of Heilongjiang Province(No.ZD2019B001)Heilongjiang Provincial Postdoctoral Research Fund(No.LBH-TZ2010).
文摘CONSPECTUS:Lithium-ion batteries have been widely applied in portable electronics due to their high energy density(300 Wh kg^(-1)).However,their potential applications in electric vehicles and grid energy storage call for higher energy density toward 500 Wh kg^(-1).Solid-state batteries,employing highly safe electrolytes to replace flammable liquid electrolytes,probably achieve this aim by reviving the metallic lithium anode.However,the sluggish lithium transport across the solid−solid interfaces seriously influences the actual battery electrochemistry in applications.Unlike the relatively complete basic theories of solid−liquid electrochemistry,the electrochemical fundamentals and models in the solid-state batteries are still ambiguous,which cannot give a guideline for optimizing strategies for high battery performance.Therefore,building better batteries for next-generation electrochemical energy storage remains a great challenge.Synchrotron X-ray imaging techniques are currently catching increasing attention due to their natural advantages,which are nondestructiveness,chemically responsiveness,elementally sensitivity,and high penetrability to enable operando investigation of a real battery.Based on the derived nanotomography techniques,it can provide 3D morphological information including thousands of slice morphologies from the bulk to the surface.Combined with X-ray absorption spectroscopy,X-ray imaging can even present chemical and phase mapping information,including the oxidation state,local environment,etc.,with sub-30 nm spatial resolution,which addresses the issues that we only obtain as averaged information in traditional X-ray absorption spectroscopy.Through an operando charging/discharging setup,X-ray imaging enables the study of the correlation between the morphology change and the chemical evolution(mapping)under different states of charge and cycling.In addition,X-ray imaging breaks up the size limit of nanoscale samples for the in-situ transmission electron microscope imaging,which enables a large,thick sample with a broad field of view,truly uncovering the behavior inside a real battery system.
