Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we p...Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.展开更多
Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evol...Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.展开更多
As the rapid development of more powerful and safer lithiumion batteries, the mechanism study of gases evolution is attacking more and more attention in recent years. Especially under overcharge/discharge and/or high-...As the rapid development of more powerful and safer lithiumion batteries, the mechanism study of gases evolution is attacking more and more attention in recent years. Especially under overcharge/discharge and/or high-temperature working condition.展开更多
In situ and operando infrared spectroscopies are powerful techniques to support the design of novel materials for batteries and the development of new battery systems.These techniques can support the study of batterie...In situ and operando infrared spectroscopies are powerful techniques to support the design of novel materials for batteries and the development of new battery systems.These techniques can support the study of batteries by identifying the formation of new species and monitoring electrochemical energy stability.However,few works have employed these techniques,which can be used to investigate various materials,including systems beyond lithium-ion technology,in the research of batteries.Therefore,this review presents a comprehensive overview focusing on the main contributions of in situ and operando infrared spectroscopy for lithium-ion batteries(LIBs)and other battery systems.These techniques can successfully identify the formation of species during the electrolyte reduction,electrode degradation,and the formation of the solid-electrolyte interphase(SEI)layer.From these outcomes,it is possible to conclude that this characterization approach should be employed as a protocol to overcome remaining issues in batteries,consequently supporting battery research.This review aims to be a guide on how infrared spectroscopy can contribute to monitoring battery systems and to lead researchers interested in applying this technique.展开更多
Herein, the electrochemical performance and the mechanism of potassium insertion/deinsertion in orthorhombic V_(2)O_(5) nanoparticles are studied. The V2O5 electrode displays an initial potassiation/depotassiation cap...Herein, the electrochemical performance and the mechanism of potassium insertion/deinsertion in orthorhombic V_(2)O_(5) nanoparticles are studied. The V2O5 electrode displays an initial potassiation/depotassiation capacity of 200 mAh g^(−1)/217 mAh g^(−1) in the voltage range 1.5–4.0 V vs. K^(+)/K at C/12 rate, suggesting fast kinetics for potassium insertion/deinsertion. However, the capacity quickly fades during cycling, reaching 54 mAh g^(−1) at the 31st cycle. Afterwards, the capacity slowly increases up to 80 mAh g^(−1) at the 200th cycle. The storage mechanism upon K ions insertion into V2O5 is elucidated. In operando synchrotron diffraction reveals that V_(2)O_(5) first undergoes a solid solution to form K_(0.6)V_(2)O_(5) phase and then, upon further K ions insertion, it reveals coexistence of a solid solution and a two-phase reaction. During K ions deinsertion, the coexistence of solid solution and the two-phase reaction is identified together with an irreversible process. In operando XAS confirms the reduction/oxidation of vanadium during the K insertion/extraction with some irreversible contributions. This is consistent with the results obtained from synchrotron diffraction, ex situ Raman, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Moreover, ex situ XPS confirms the “cathode electrolyte interphase” (CEI) formation on the electrode and the decomposition of CEI film during cycling.展开更多
Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applica...Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.展开更多
The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provi...The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provide an additional capacity for Li storage,but it suffers from a severe capacity degradation.In this study,operando X-ray diffraction is carried out to investigate the structural evolutions and degradation mechanisms of LiMn2O4 in different voltage ranges.In the range of 3.0-4.3 V(vs.Li^+/Li),the LiMn2O4 cathode exhibits a low capacity but good cycling stability with cycles up to 100 cycles and the charge/discharge processes are associated with the reversible extraction/insertion of Li^+from/into LixMn2O4(0≤x≤1).In the range of 1.4-4.4 V(vs.Li^+/Li),a capacity higher than 200 mAh/g is achieved,but it rapidly decays during the cycling.The voltage plateau around 2.8 V(vs.Li^+/Li)is related to the transformation of the cubic LiMn2O4 phase to the tetragonal Li2Mn2O4 phase,which leads to the formation of cracks as well as the performance degradation.展开更多
Internal gases caused by side reactions are crucial signals for evaluating health and safety states of Li-ion batteries(LIBs)while it is still a great challenge to timely realize accurate monitoring.To address the iss...Internal gases caused by side reactions are crucial signals for evaluating health and safety states of Li-ion batteries(LIBs)while it is still a great challenge to timely realize accurate monitoring.To address the issues of implanting various gas sensors into commercial batteries,here a novel method is developed to fast operando monitoring gas evolution via equipping non-dispersive infrared multi-gases sensors into a sealed tank,where real commercial batteries with one open end could be settled for operating.The generated CO_(2)concentration is strongly linked with both voltage and temperature,while the concentrations of CH_(4) and C_(2)H_(4) are solely dependent on temperature.As a typical trace gas,evolution behaviors of CO_(2)have been related to 0_(2) generation from LiNi_(o.5)Mn_(0.3)CoO_(2)0_(2) positive electrode,implying stable CO_(2)release below a critical voltage of 4.5 V.By tracking CO_(2)concentration,an increased amount of Li_(2)CO_(3) was monitored on the surface of graphite negative electrode during discharge process at dfferent temperatures and cutoff voltages,which contributes to the component variation of solid electrolyte interfaces.Such operando techniques promise a plaform for well understanding the interaction of side reactions linked with gas evolution between positive and negative electrodes in commercial LIBs.展开更多
The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,convention...The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.展开更多
Graphite has been currently considered as a promising cathode material in dual ion batteries(DIBs)due to its unique features of sp2 hybridized carbon and stacked two-dimensional layered structures.However,unexpected v...Graphite has been currently considered as a promising cathode material in dual ion batteries(DIBs)due to its unique features of sp2 hybridized carbon and stacked two-dimensional layered structures.However,unexpected volume/thickness changes in the graphite cathodes,induced by the intercalation/deintercalation of anions with large molecular size have been known to be a critical problem in designing DIB cells.To understand the volume/thickness changes in the DIB electrodes,in operando optical observing apparatus has been employed to observe the cross-section view of a graphite-based cathode upon cycles in the present work.The observation suggests that the cathode initially presented a huge irreversible thickness change(60%),and such thickness variation was prone to reduce and remain <20% in the following cycles.The results from both in operando observation and electrochemical characterizations collectively indicate that the greater thickness variation at initial cycle should be attributed to both anion intercalation into graphite-based cathodes and irreversible decomposition of chemical components in the DIB system.The method here highlights a universal route for fundamentally understanding the electrodes of huge volume variation.展开更多
In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for met...In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for methanol synthesis. In this work, the catalyst, whose activity increases with the reaction temperature and pressure, was studied at calcined, reduced, and reacted conditions. TEM and EDX images for the calcined and reduced catalysts showed that copper was distributed uniformly at both conditions. TPR profile revealed two reduction peaks at 165 and 195 °C for copper species in the calcined catalyst. QXAFS results demonstrated that the calcined form consisted mainly of a mixed Cu O and Zn O, and it was progressively transformed into Cu metal particles and dispersed Zn O species as the reduction treatment. It was demonstrated that activation of the catalyst precursor occurred via a Cu^+intermediate, and the active catalyst predominantly consisted of metallic Cu and Zn O evenunder higher pressures. Structure of the active catalyst did not change with the temperature or pressure, indicating that the role of the Zn was mainly to improve Cu dispersion.This indicates the potential of QXAFS method in studying the structure evolutions of catalysts in methanol synthesis.展开更多
Electrochemical water splitting has attracted considerable attention for the production of hydrogen fuel by using renewable energy resources.However,the sluggish reaction kinetics make it essential to explore precious...Electrochemical water splitting has attracted considerable attention for the production of hydrogen fuel by using renewable energy resources.However,the sluggish reaction kinetics make it essential to explore precious-metal-free electrocatalysts with superior activity and long-term stability.Tremendous efforts have been made in exploring electrocatalysts to reduce the energy barriers and improve catalytic efficiency.This review summarizes different categories of precious-metal-free electrocatalysts developed in the past 5 years for alkaline water splitting.The design strategies for optimizing the electronic and geometric structures of electrocatalysts with enhanced catalytic performance are discussed,including composition modulation,defect engineering,and structural engineering.Particularly,the advancement of operando/in situ characterization techniques toward the understanding of structural evolution,reaction intermediates,and active sites during the water splitting process are summarized.Finally,current challenges and future perspectives toward achieving efficient catalyst systems for industrial applications are proposed.This review will provide insights and strategies to the design of precious-metalfree electrocatalysts and inspire future research in alkaline water splitting.展开更多
The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusi...The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.展开更多
Solid-liquid phase conversion between various sulfur species in lithium-sulfur(Li-S)batteries is a fundamental reaction of the sulfur cathode.Disclosing the morphological evolution of solid sulfur species upon cycling...Solid-liquid phase conversion between various sulfur species in lithium-sulfur(Li-S)batteries is a fundamental reaction of the sulfur cathode.Disclosing the morphological evolution of solid sulfur species upon cycling is of great significance to achieving high energy densities.However,an in-depth investigation of the internal reaction is still lacking.In this work,the evolution process of solid sulfur species on carbon substrates is systematically studied by using an operando light microscope combined with in situ electrochemical impedance spectra technology.The observation of phenomena such as bulk solid sulfur species can form and dissolve independently of the conductive substrates and the transformation of supercooled liquid sulfur to crystalline sulfur.Based on the phenomena mentioned above,a possible mechanism was proposed in which the dissolution reaction of solid sulfur species is a spatially free reaction that involves isotropic physical dissolution,diffusion of molecules,and finally the electrochemical reaction.Correspondingly,the formation of solid sulfur species tends to be a form of crystallization in a saturated solution rather than electrodeposition,as is commonly believed.Our findings offer new insights into the reaction of sulfur cathodes and provide new opportunities to design advanced sulfur cathodes for Li-S batteries.展开更多
The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to g...The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realistic operation conditions, which can be obtained by in-situ/operando characterization techniques for organic devices. Here, the up-todate developments in the in-situ/operando optical, scanning probe microscopy, and spectroscopy techniques that are employed for studies of film morphological evolution, crystal structures, semiconductor-electrolyte interface properties, and charge carrier dynamics are described and summarized. These advanced technologies leverage the traditional static characterizations into an in-situ and interactive manipulation of organic semiconducting films and devices without sacrificing the resolution, which facilitates the exploration of the intrinsic structure-property relationship of organic materials and the optimization of organic devices for advanced applications.展开更多
The lightweight,rechargeable lithium-ion battery is one of the dominant energy storage devices globally in portable electronics due to its high energy density,no memory effect,wide operating voltage,lightweight,and go...The lightweight,rechargeable lithium-ion battery is one of the dominant energy storage devices globally in portable electronics due to its high energy density,no memory effect,wide operating voltage,lightweight,and good charge efficiency.However,due to safety concerns,the depletion of lithium reserves,and the corresponding increase of cost,an alternative battery system becomes more and more desirable.To develop alternative battery systems with low cost and high material abundance,for example,sodium,magnesium,zinc,and calcium,it is important to understand the chemical and electronic structure of materials.Soft X-ray spectroscopy,for example,X-ray absorption spectroscopy(XAS),X-ray emission spectroscopy(XES),and resonant inelastic soft X-ray scattering(RIXS),is an element-specific technique with sensitivity to the local chemical environment and structural order of the element of interest.Modern soft X-ray systems enable operando experiments that can be applied to amorphous and crystalline samples,making it a powerful tool for studying the electronic and structural changes in electrode and electrolyte species.In this article,the application of in situ/operando(soft)X-ray spectroscopy in beyond lithium-ion batteries is reviewed to demonstrate how such spectroscopic characterizations could facilitate the interpretation of interfacial phenomena under in situ/operando condition and subsequent development of the beyond lithium-ion batteries.展开更多
Chromium(VI)(Cr(VI)),a toxic metal ion,is widely present in industrial wastewater.To reduce the contamination of Cr(VI),many technologies for the photocatalytic reduction of Cr(VI)to Cr(III)have been developed in the ...Chromium(VI)(Cr(VI)),a toxic metal ion,is widely present in industrial wastewater.To reduce the contamination of Cr(VI),many technologies for the photocatalytic reduction of Cr(VI)to Cr(III)have been developed in the past decades.However,the practical application of photocatalysts for the reduction of Cr(VI)inwastewater treatment is often hindered by the complicated photoreduction processes due to the sedimentation and stratification of catalyst particles that present during the treatment of the wastewater.Probing and understanding the influences of the sedimentation and stratification of the catalyst particles on the photoreduction processes are long-term challenges in the field.Herein,we demonstrate that this issue can be solved by using layer location integrated low-field time-domain nuclear magnetic resonance(LF-NMR)relaxometry.With paramagnetic Cr(III)cation as the molecular probe,we successfully monitored the Cr(VI)photoreduction processes by operando probing the 1 H T2 relaxation time of the photoreduction systems.The influences of catalyst sedimentation and the light wavelength on photocatalysis were studied and discussed.The results showed the great potential of LF-NMR relaxometry in the study of Cr(VI)photoreduction processes during industrial wastewater treatments.展开更多
Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due t...Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due to particle re-entrainment.Here,Operando observation system based on microscopic visualization method is developed to make in situ test of particle migration,deposition and re-entrainment characteristics on a lab-on-a-chip to achieve the investigation in micro-level scale.The deposition evolution of charged particles is recorded in electric field region intuitively,which confirms the fracture of particle chain occurs during the growth process of deposited particles.It captures the instantaneous process that a larger particle with micron size due to the coagulation of submicron particles fractures from main body of the particle chain for the first time.The analysis of migration behavior of a single submicron particle near electrode surface demonstrates the direct influence of drag force on the fracture of particle chain.This work is the first-time visualization of dynamic process and mechanism elucidation of particle re-entrainment at the micron level,and the findings will provide the theory support for the particle re-entrainment mechanism and bring inspires of enhancing capture efficiency of inhalable particle.展开更多
基金funded by the Australian Research Council Discovery Projects(DP160104835,Z.Shao)the Guangdong Basic and Applied Basic Research Foundation(2023A1515012878,D.Guan)+1 种基金the PolyU Distinguished Postdoctoral Fellowship Scheme(1-YWBU,D.Guan)the support from the Max Planck-POSTECH-Hsinchu Center for Complex Phase Materials。
文摘Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.
基金sponsored by the Helmholtz Association,the China Scholarship Council(CSC)partially funded by the German Research Foundation,DFG(Project No.MA 5039/4-1)。
文摘Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.
基金partially supported by the National Natural Science Foundation of China (grant no. 22021001, 22179111)the Ministry of Science and Technology of China (grant no. 2021YFA1201900)+3 种基金the Basic Research Program of Tan Kah Kee Innovation Laboratory (grant no. RD2021070401)the Principal Fund from Xiamen University (grant no. 20720210015)the Fundamental Research Funds for the Central Universities (grant no. 20720220010)the National Natural Science Foundation of China (grant no. 22202082)。
文摘As the rapid development of more powerful and safer lithiumion batteries, the mechanism study of gases evolution is attacking more and more attention in recent years. Especially under overcharge/discharge and/or high-temperature working condition.
基金the financial support received from Kansas State University and the UNICAMP Development Foundation (FUNCAMP)the Brazilian Coordination for the Improvement of Higher Education Personnel–CAPES (Pr Int 88887.572651/2020-00+8 种基金88887.374731/2019-00)the financial support from the Brazilian National Council for Scientific and Technological Development–CNPq (310544/2019-0-PQ-2 grant)the S?o Paulo Research Foundation–FAPESP (2020/04431-02017/11958-12014/02163-7)the UNICAMP Development Foundation–FUNCAMP,Shellthe strategic importance of the support given by Brazil’s National Oil,Natural Gas,and Biofuels Agency–ANP via the R&D levy regulationNational Science Foundation Grant (1743701)CMMI NSF CAREER Grant (1454151)。
文摘In situ and operando infrared spectroscopies are powerful techniques to support the design of novel materials for batteries and the development of new battery systems.These techniques can support the study of batteries by identifying the formation of new species and monitoring electrochemical energy stability.However,few works have employed these techniques,which can be used to investigate various materials,including systems beyond lithium-ion technology,in the research of batteries.Therefore,this review presents a comprehensive overview focusing on the main contributions of in situ and operando infrared spectroscopy for lithium-ion batteries(LIBs)and other battery systems.These techniques can successfully identify the formation of species during the electrolyte reduction,electrode degradation,and the formation of the solid-electrolyte interphase(SEI)layer.From these outcomes,it is possible to conclude that this characterization approach should be employed as a protocol to overcome remaining issues in batteries,consequently supporting battery research.This review aims to be a guide on how infrared spectroscopy can contribute to monitoring battery systems and to lead researchers interested in applying this technique.
基金This work contributes to the research performed at CELEST(Center for Electrochemical Energy Storage Ulm-Karlsruhe)and was funded by the German Research Foundation(DFG)under Project ID 390874152(POLiS Cluster of Excellence)Our research work has gained benefit from beamtime allocation(2017092405-qfu)at BL04-MSPD at ALBA Synchrotron,Barcelona,Spain and(I-20170977)at PETRA-III beamline P65 at DESY,Hamburg,Germany.The in operando XAS work was performed by using the Biologic potentiostat of PETRA-Ⅲ beamline P02.1.We thank Dr.Francois Fauth from Experiments Division at ALBA for his technical help during synchrotron diffraction measurement.We appreciate Dr.Anna-Lena Hansen(IAM-ESS)for the helpful discussion regarding to the crystal sturcture of V_(2)O_(5).Dr.Kristina Pfeifer(IAM-ESS),Dr.Noha Sabi(IAM-ESS),and Dr.Thomas Bergfeldt(IAM-AWP)are gratefully acknowledged for SEM/EDX,FTIR,and ICP-OES measurements,respectively.The TEM characterization was carried out at the Karlsruhe Nano Micro Facility(KNMF),a Helmholtz research infrastructure operated at the KIT.
文摘Herein, the electrochemical performance and the mechanism of potassium insertion/deinsertion in orthorhombic V_(2)O_(5) nanoparticles are studied. The V2O5 electrode displays an initial potassiation/depotassiation capacity of 200 mAh g^(−1)/217 mAh g^(−1) in the voltage range 1.5–4.0 V vs. K^(+)/K at C/12 rate, suggesting fast kinetics for potassium insertion/deinsertion. However, the capacity quickly fades during cycling, reaching 54 mAh g^(−1) at the 31st cycle. Afterwards, the capacity slowly increases up to 80 mAh g^(−1) at the 200th cycle. The storage mechanism upon K ions insertion into V2O5 is elucidated. In operando synchrotron diffraction reveals that V_(2)O_(5) first undergoes a solid solution to form K_(0.6)V_(2)O_(5) phase and then, upon further K ions insertion, it reveals coexistence of a solid solution and a two-phase reaction. During K ions deinsertion, the coexistence of solid solution and the two-phase reaction is identified together with an irreversible process. In operando XAS confirms the reduction/oxidation of vanadium during the K insertion/extraction with some irreversible contributions. This is consistent with the results obtained from synchrotron diffraction, ex situ Raman, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Moreover, ex situ XPS confirms the “cathode electrolyte interphase” (CEI) formation on the electrode and the decomposition of CEI film during cycling.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20170630)the National Natural Science Foundation of China(51802149 and U1801251)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Nanjing University Technology Innovation Fund Project。
文摘Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.
基金the financial support by the National Natural Science Foundation of China (51871133, 51671115)support by the Department of Science and Technology of the Shandong Province for the Young Tip-Top Talent Support Project.
文摘The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provide an additional capacity for Li storage,but it suffers from a severe capacity degradation.In this study,operando X-ray diffraction is carried out to investigate the structural evolutions and degradation mechanisms of LiMn2O4 in different voltage ranges.In the range of 3.0-4.3 V(vs.Li^+/Li),the LiMn2O4 cathode exhibits a low capacity but good cycling stability with cycles up to 100 cycles and the charge/discharge processes are associated with the reversible extraction/insertion of Li^+from/into LixMn2O4(0≤x≤1).In the range of 1.4-4.4 V(vs.Li^+/Li),a capacity higher than 200 mAh/g is achieved,but it rapidly decays during the cycling.The voltage plateau around 2.8 V(vs.Li^+/Li)is related to the transformation of the cubic LiMn2O4 phase to the tetragonal Li2Mn2O4 phase,which leads to the formation of cracks as well as the performance degradation.
基金supported by the National Key R&D Program of China(Grant No.2021YFB2401900)the National Natural Science Foundation of China(Grant Nos.11672341,11572002,52074036)+1 种基金the Technology Innovation Program of Beijing Institute of Technology(Grant No.2019CX01021)the BIT Teli Young Fellow。
文摘Internal gases caused by side reactions are crucial signals for evaluating health and safety states of Li-ion batteries(LIBs)while it is still a great challenge to timely realize accurate monitoring.To address the issues of implanting various gas sensors into commercial batteries,here a novel method is developed to fast operando monitoring gas evolution via equipping non-dispersive infrared multi-gases sensors into a sealed tank,where real commercial batteries with one open end could be settled for operating.The generated CO_(2)concentration is strongly linked with both voltage and temperature,while the concentrations of CH_(4) and C_(2)H_(4) are solely dependent on temperature.As a typical trace gas,evolution behaviors of CO_(2)have been related to 0_(2) generation from LiNi_(o.5)Mn_(0.3)CoO_(2)0_(2) positive electrode,implying stable CO_(2)release below a critical voltage of 4.5 V.By tracking CO_(2)concentration,an increased amount of Li_(2)CO_(3) was monitored on the surface of graphite negative electrode during discharge process at dfferent temperatures and cutoff voltages,which contributes to the component variation of solid electrolyte interfaces.Such operando techniques promise a plaform for well understanding the interaction of side reactions linked with gas evolution between positive and negative electrodes in commercial LIBs.
基金supported by the National Natural Science Foundation of China,grant number:U1732267.
文摘The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.
基金Financial support from 973 Project (2015CB932500)the National Natural Science Foundation of China (11672341,111572002,51302011)+2 种基金Innovative Research Groups of the National Natural Science Foundation of China (11521202)National Materials Genome Project (2016YFB0700600)Beijing Natural Science Foundation (16L00001,2182065) is gratefully acknowledged
文摘Graphite has been currently considered as a promising cathode material in dual ion batteries(DIBs)due to its unique features of sp2 hybridized carbon and stacked two-dimensional layered structures.However,unexpected volume/thickness changes in the graphite cathodes,induced by the intercalation/deintercalation of anions with large molecular size have been known to be a critical problem in designing DIB cells.To understand the volume/thickness changes in the DIB electrodes,in operando optical observing apparatus has been employed to observe the cross-section view of a graphite-based cathode upon cycles in the present work.The observation suggests that the cathode initially presented a huge irreversible thickness change(60%),and such thickness variation was prone to reduce and remain <20% in the following cycles.The results from both in operando observation and electrochemical characterizations collectively indicate that the greater thickness variation at initial cycle should be attributed to both anion intercalation into graphite-based cathodes and irreversible decomposition of chemical components in the DIB system.The method here highlights a universal route for fundamentally understanding the electrodes of huge volume variation.
基金supported by the National Basic Research Program of China(973 Program,2013CB933104)the National Natural Science Foundation of China(Nos.11275258 and 11135008)
文摘In situ quick X-ray absorption spectroscopy(QXAFS) at the Cu and Zn K-edge under operando conditions has been used to unravel the Cu/Zn interaction and identify possible active site of CuO/ZnO/Al_2O_3 catalyst for methanol synthesis. In this work, the catalyst, whose activity increases with the reaction temperature and pressure, was studied at calcined, reduced, and reacted conditions. TEM and EDX images for the calcined and reduced catalysts showed that copper was distributed uniformly at both conditions. TPR profile revealed two reduction peaks at 165 and 195 °C for copper species in the calcined catalyst. QXAFS results demonstrated that the calcined form consisted mainly of a mixed Cu O and Zn O, and it was progressively transformed into Cu metal particles and dispersed Zn O species as the reduction treatment. It was demonstrated that activation of the catalyst precursor occurred via a Cu^+intermediate, and the active catalyst predominantly consisted of metallic Cu and Zn O evenunder higher pressures. Structure of the active catalyst did not change with the temperature or pressure, indicating that the role of the Zn was mainly to improve Cu dispersion.This indicates the potential of QXAFS method in studying the structure evolutions of catalysts in methanol synthesis.
基金This study was funded by the Australian Research Council(FT170100224)the Australian Renewable Energy Agency+1 种基金National Natural Science Foundation of China(21825501)the Tsinghua University Initiative Scientific Research Program.
文摘Electrochemical water splitting has attracted considerable attention for the production of hydrogen fuel by using renewable energy resources.However,the sluggish reaction kinetics make it essential to explore precious-metal-free electrocatalysts with superior activity and long-term stability.Tremendous efforts have been made in exploring electrocatalysts to reduce the energy barriers and improve catalytic efficiency.This review summarizes different categories of precious-metal-free electrocatalysts developed in the past 5 years for alkaline water splitting.The design strategies for optimizing the electronic and geometric structures of electrocatalysts with enhanced catalytic performance are discussed,including composition modulation,defect engineering,and structural engineering.Particularly,the advancement of operando/in situ characterization techniques toward the understanding of structural evolution,reaction intermediates,and active sites during the water splitting process are summarized.Finally,current challenges and future perspectives toward achieving efficient catalyst systems for industrial applications are proposed.This review will provide insights and strategies to the design of precious-metalfree electrocatalysts and inspire future research in alkaline water splitting.
基金financially supported by the National Key R&D Program of China(2016YFB0100100)the National Natural Science Foundation of China(Nos.21433013,U1832218)the support from China Scholarship Council
文摘The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.
基金the financial support from The National Key Research and Development Program of China(2018YFB0104200)。
文摘Solid-liquid phase conversion between various sulfur species in lithium-sulfur(Li-S)batteries is a fundamental reaction of the sulfur cathode.Disclosing the morphological evolution of solid sulfur species upon cycling is of great significance to achieving high energy densities.However,an in-depth investigation of the internal reaction is still lacking.In this work,the evolution process of solid sulfur species on carbon substrates is systematically studied by using an operando light microscope combined with in situ electrochemical impedance spectra technology.The observation of phenomena such as bulk solid sulfur species can form and dissolve independently of the conductive substrates and the transformation of supercooled liquid sulfur to crystalline sulfur.Based on the phenomena mentioned above,a possible mechanism was proposed in which the dissolution reaction of solid sulfur species is a spatially free reaction that involves isotropic physical dissolution,diffusion of molecules,and finally the electrochemical reaction.Correspondingly,the formation of solid sulfur species tends to be a form of crystallization in a saturated solution rather than electrodeposition,as is commonly believed.Our findings offer new insights into the reaction of sulfur cathodes and provide new opportunities to design advanced sulfur cathodes for Li-S batteries.
基金support from Natural Science Foundation of Jiangsu Province (grant number BK20211507)National Natural Science Foundation of China (grant number 61774080)the start-up funds from Changzhou University。
文摘The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realistic operation conditions, which can be obtained by in-situ/operando characterization techniques for organic devices. Here, the up-todate developments in the in-situ/operando optical, scanning probe microscopy, and spectroscopy techniques that are employed for studies of film morphological evolution, crystal structures, semiconductor-electrolyte interface properties, and charge carrier dynamics are described and summarized. These advanced technologies leverage the traditional static characterizations into an in-situ and interactive manipulation of organic semiconducting films and devices without sacrificing the resolution, which facilitates the exploration of the intrinsic structure-property relationship of organic materials and the optimization of organic devices for advanced applications.
基金supported as part of the Joint Center for Energy Storage Research(JCESR)an Energy Innovation Hub funded by the U.S.Department of Energy(DOE),Office of Science,Basic Energy Sciences
文摘The lightweight,rechargeable lithium-ion battery is one of the dominant energy storage devices globally in portable electronics due to its high energy density,no memory effect,wide operating voltage,lightweight,and good charge efficiency.However,due to safety concerns,the depletion of lithium reserves,and the corresponding increase of cost,an alternative battery system becomes more and more desirable.To develop alternative battery systems with low cost and high material abundance,for example,sodium,magnesium,zinc,and calcium,it is important to understand the chemical and electronic structure of materials.Soft X-ray spectroscopy,for example,X-ray absorption spectroscopy(XAS),X-ray emission spectroscopy(XES),and resonant inelastic soft X-ray scattering(RIXS),is an element-specific technique with sensitivity to the local chemical environment and structural order of the element of interest.Modern soft X-ray systems enable operando experiments that can be applied to amorphous and crystalline samples,making it a powerful tool for studying the electronic and structural changes in electrode and electrolyte species.In this article,the application of in situ/operando(soft)X-ray spectroscopy in beyond lithium-ion batteries is reviewed to demonstrate how such spectroscopic characterizations could facilitate the interpretation of interfacial phenomena under in situ/operando condition and subsequent development of the beyond lithium-ion batteries.
基金supported by the National Natural Science Foundation of China(grant nos.22072045,21603073,and 21574043)the Ministry of Science and Technology of the People's Republic of China(grant no.2018YFC1602800)Xing-FuZhi-Hua Foundation of ECNU and Microscale Magnetic Resonance Platform of ECNU and the Microscale Magnetic Resonance Platform of ECNU.
文摘Chromium(VI)(Cr(VI)),a toxic metal ion,is widely present in industrial wastewater.To reduce the contamination of Cr(VI),many technologies for the photocatalytic reduction of Cr(VI)to Cr(III)have been developed in the past decades.However,the practical application of photocatalysts for the reduction of Cr(VI)inwastewater treatment is often hindered by the complicated photoreduction processes due to the sedimentation and stratification of catalyst particles that present during the treatment of the wastewater.Probing and understanding the influences of the sedimentation and stratification of the catalyst particles on the photoreduction processes are long-term challenges in the field.Herein,we demonstrate that this issue can be solved by using layer location integrated low-field time-domain nuclear magnetic resonance(LF-NMR)relaxometry.With paramagnetic Cr(III)cation as the molecular probe,we successfully monitored the Cr(VI)photoreduction processes by operando probing the 1 H T2 relaxation time of the photoreduction systems.The influences of catalyst sedimentation and the light wavelength on photocatalysis were studied and discussed.The results showed the great potential of LF-NMR relaxometry in the study of Cr(VI)photoreduction processes during industrial wastewater treatments.
基金supported by the National Natural Science Foundation of China (Nos.52200130 and 22176123)Postdoctoral Science Foundation of China (No.2022M722082)the National Key Research&Development Plan (No.2017YFC0211804)。
文摘Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due to particle re-entrainment.Here,Operando observation system based on microscopic visualization method is developed to make in situ test of particle migration,deposition and re-entrainment characteristics on a lab-on-a-chip to achieve the investigation in micro-level scale.The deposition evolution of charged particles is recorded in electric field region intuitively,which confirms the fracture of particle chain occurs during the growth process of deposited particles.It captures the instantaneous process that a larger particle with micron size due to the coagulation of submicron particles fractures from main body of the particle chain for the first time.The analysis of migration behavior of a single submicron particle near electrode surface demonstrates the direct influence of drag force on the fracture of particle chain.This work is the first-time visualization of dynamic process and mechanism elucidation of particle re-entrainment at the micron level,and the findings will provide the theory support for the particle re-entrainment mechanism and bring inspires of enhancing capture efficiency of inhalable particle.