Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical...Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical energy stor-age devices at all technology readiness levels.Due to various challenging issues,especially limited stability,nano-and micro-structured(NMS)electrodes undergo fast electrochemical performance degradation.The emerging NMS scaffold design is a pivotal aspect of many electrodes as it endows them with both robustness and electrochemical performance enhancement,even though it only occupies comple-mentary and facilitating components for the main mechanism.However,extensive efforts are urgently needed toward optimizing the stereoscopic geometrical design of NMS scaffolds to minimize the volume ratio and maximize their functionality to fulfill the ever-increasing dependency and desire for energy power source supplies.This review will aim at highlighting these NMS scaffold design strategies,summariz-ing their corresponding strengths and challenges,and thereby outlining the potential solutions to resolve these challenges,design principles,and key perspectives for future research in this field.Therefore,this review will be one of the earliest reviews from this viewpoint.展开更多
Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT...Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.展开更多
The electrochemical reduction of carbon dioxide offers a sound and economically viable technology for the electrification and decarbonization of the chemical and fuel industries.In this technology,an electrocatalytic ...The electrochemical reduction of carbon dioxide offers a sound and economically viable technology for the electrification and decarbonization of the chemical and fuel industries.In this technology,an electrocatalytic material and renewable energy-generated electricity drive the conversion of carbon dioxide into high-value chemicals and carbon-neutral fuels.Over the past few years,single-atom catalysts have been intensively studied as they could provide near-unity atom utilization and unique catalytic performance.Single-atom catalysts have become one of the state-of-the-art catalyst materials for the electrochemical reduction of carbon dioxide into carbon monoxide.However,it remains a challenge for single-atom catalysts to facilitate the efficient conversion of carbon dioxide into products beyond carbon monoxide.In this review,we summarize and present important findings and critical insights from studies on the electrochemical carbon dioxide reduction reaction into hydrocarbons and oxygenates using single-atom catalysts.It is hoped that this review gives a thorough recapitulation and analysis of the science behind the catalysis of carbon dioxide into more reduced products through singleatom catalysts so that it can be a guide for future research and development on catalysts with industry-ready performance for the electrochemical reduction of carbon dioxide into high-value chemicals and carbon-neutral fuels.展开更多
The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-b...The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes(GDE),and the effect of nitrogen(N)doping on the ECR activity of ZnO electrocatalysts was investigated.Initially,a ZnO nanosheet was prepared via the hydrothermal method,and nitridation was performed at different times to control the N-doping content.With an increase in the N-doping content,the morphological properties of the nanosheet changed significantly,namely,the 2D nanosheets transformed into irregularly shaped nanoparticles.Furthermore,the ECR performance of Zn O electrocatalysts with different N-doping content was assessed in 1.0 M KHCO_(3) electrolyte using a gas-diffusion electrode-based ECR cell.While the ECR activity increased after a small amount of N doping,it decreased for higher N doping content.Among them,the N:ZnO-1 h electrocatalysts showed the best CO selectivity,with a faradaic efficiency(FE_(CO))of 92.7%at-0.73 V vs.reversible hydrogen electrode(RHE),which was greater than that of an undoped Zn O electrocatalyst(FE_(CO)of 63.4%at-0.78 V_(RHE)).Also,the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h,with a partial current density of-92.1 mA cm^(-2).This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations,demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from(ⅰ)the optimized active sites lowering the free energy barrier for the rate-determining step(RDS),and(ⅱ)the modification of electronic structure enhancing the electron transfer rate by N doping.展开更多
Aqueous zinc-ion batteries(AZIBs)are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability.In response to the growing demand for green and sustainable en...Aqueous zinc-ion batteries(AZIBs)are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability.In response to the growing demand for green and sustainable energy storage solutions,organic electrodes with the scalability from inexpensive starting materials and potential for biodegradation after use have become a prominent choice for AZIBs.Despite gratifying progresses of organic molecules with electrochemical performance in AZIBs,the research is still in infancy and hampered by certain issues due to the underlying complex electrochemistry.Strategies for designing organic electrode materials for AZIBs with high specific capacity and long cycling life are discussed in detail in this review.Specifically,we put emphasis on the unique electrochemistry of different redox-active structures to provide in-depth understanding of their working mechanisms.In addition,we highlight the importance of molecular size/dimension regarding their profound impact on electrochemical performances.Finally,challenges and perspectives are discussed from the developing point of view for future AZIBs.We hope to provide a valuable evaluation on organic electrode materials for AZIBs in our context and give inspiration for the rational design of high-performance AZIBs.展开更多
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro...In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.展开更多
For the challenging nature of the zirconium environment analysis, this study consists to analyze the electrochemical behavior of Zirconium in both aqueous and organic media. To that end first the electrolytic media wa...For the challenging nature of the zirconium environment analysis, this study consists to analyze the electrochemical behavior of Zirconium in both aqueous and organic media. To that end first the electrolytic media was selected on the basis of the Pourbaix potential-pH diagram, which provides informations on the predominance of Zr<sup>(IV) </sup> ion and Zr in aqueous media. In aqueous media, analyzes were first carried out in acidic media then in basic media. Studies have thus revealed that the acidic environment is not favourable for the electrochemical analysis of zirconium. Voltammograms obtained in an acidic environment show no zirconium detection signal;this is due to the strong presence of H<sup>+</sup> ions in the solution. We have also observed in acidic media the phenomenon of passivation of the electrode surface. In aqueous alkaline media (pH = 13), we have drawn in reduction several Intensity-Potential curves by fixingsome technical parameterslike scanning speed, rotation speed of the electrode. The obtained voltammograms show cathodic waves, starting from -1.5 V/DHW and attributed to the reduction of Zr<sup> (IV) </sup> to Zr (0). The last phase of this study focused on the electrochemical analysis of zirconium in an organic media. In this media, several intensity-potential curves were plotted in reduction and in cyclic voltammetry with various parameters. Through several reduction analysis, the Zr<sup> (IV) </sup> was reduced to Zr (0) to the potential of -1.5 V/DHW. The electrochemical analysis of zirconium in organic media seems globally easier to achieve thanks to its large solvent window (i.e. dimethylformamide (DMF) solvent window > 6 V).展开更多
Dissolved oxygen(DO)usually refers to the amount of oxygen dissolved in water.In the environment,medicine,and fermentation industries,the DO level needs to be accurate and capable of online monitoring to guide the pre...Dissolved oxygen(DO)usually refers to the amount of oxygen dissolved in water.In the environment,medicine,and fermentation industries,the DO level needs to be accurate and capable of online monitoring to guide the precise control of water quality,clinical treatment,and microbial metabolism.Compared with other analytical methods,the electrochemical strategy is superior in its fast response,low cost,high sensitivity,and portable device.However,an electrochemical DO sensor faces a trade-off between sensitivity and long-term stability,which strongly limits its practical applications.To solve this problem,various advanced nanomaterials have been proposed to promote detection performance owing to their excellent electrocatalysis,conductivity,and chemical stability.Therefore,in this review,we focus on the recent progress of advanced nanomaterial-based electrochemical DO sensors.Through the comparison of the working principles on the main analysis techniques toward DO,the advantages of the electrochemical method are discussed.Emphasis is placed on recently developed nanomaterials that exhibit special characteristics,including nanostructures and preparation routes,to benefit DO determination.Specifically,we also introduce some interesting research on the configuration design of the electrode and device,which is rarely introduced.Then,the different requirements of the electrochemical DO sensors in different application fields are included to provide brief guidance on the selection of appropriate nanomaterials.Finally,the main challenges are evaluated to propose future development prospects and detection strategies for nanomaterial-based electrochemical sensors.展开更多
The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy s...The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy storage.Unfortunately,the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity,which seriously limit the application of Mg-based materials in supercapacitors.Herein,in this review,more than 70 research papers published in recent 10 years were collected and analyzed.Some representative research works were selected,and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were discussed.The effects of various regulative strategies(such as constructing nanostructures,synthesizing composites,defect engineering,and binder-free synthesis,etc.)on the electrochemical performance and their mechanism are demonstrated using spinelstructured MgX_(2)O_(4) and layered structured Mg-X-LDHs as examples.In addition,the application of magnesium oxide and magnesium hydroxide in electrode materials,MXene's solid spacers and hard templates are introduced.Finally,the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.展开更多
The development of lithium-sulfur(Li-S)batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge.Herein,the...The development of lithium-sulfur(Li-S)batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge.Herein,the crystallinities of a titanium nitride(TiN)film on copper-embedded carbon nanofibers(Cu-CNFs)are regulated and the nanofibers are used as interlayers to resolve the aforementioned crucial issues.A low-crystalline TiN-coated Cu-CNF(L-TiN-Cu-CNF)interlayer is compared with its highly crystalline counterpart(H-TiN-Cu-CNFs).It is demonstrated that the L-TiN coating not only strengthens the chemical adsorption toward polysulfides but also greatly accelerates the electrochemical conversion of polysulfides.Due to robust carbon frameworks and enhanced kinetics,impressive highrate performance at 2 C(913 mAh g^(-1)based on sulfur)as well as remarkable cyclic stability up to 300 cycles(626 mAh g^(-1))with capacity retention of 46.5%is realized for L-TiN-Cu-CNF interlayer-configured Li-S batteries.Even under high loading(3.8 mg cm^(-2))of sulfur and relatively lean electrolyte(10μL electrolyte per milligram sulfur)conditions,the Li-S battery equipped with L-TiN-Cu-CNF interlayers delivers a high capacity of 1144 mAh g^(-1)with cathodic capacity of 4.25 mAh cm^(-2)at 0.1 C,providing a potential pathway toward the design of multifunctional interlayers for highly efficient Li-S batteries.展开更多
The durability of reinforced concrete structures is greatly influenced by the corrosion of the reinforcement. In addition to air pollution related to the repair of corroded structures, chloride ions are the main facto...The durability of reinforced concrete structures is greatly influenced by the corrosion of the reinforcement. In addition to air pollution related to the repair of corroded structures, chloride ions are the main factors of corrosion of reinforced concrete structures. This study aims to valorize a clay inhibitor against reinforcement corrosion in reinforced concrete. This clay (Attapulgite) was incorporated into reinforced concretes at different percentages of substitution of calcined attapulgite (0%, 5% and 10%) to cement in the formulation. The corrosion inhibitory power of attapulgite is evaluated in reinforced concretes subjected to the action of chloride ions at different intervals in the NaCl solution (1 day, 21 days and 45 days) by electrochemical methods (zero current chronopotentiometry, polarization curves and electrochemical impedance spectroscopy). This study showed that in the presence of chloride ions, the composition based on 10% attapulgite has an appreciable inhibitory effect with an average inhibitory efficiency of 82%.展开更多
The development of freestanding and binder-free electrode is an effective approach to perform the inherent capacity of active materials and promote the mechanism study by minimizing the interference from additives.Her...The development of freestanding and binder-free electrode is an effective approach to perform the inherent capacity of active materials and promote the mechanism study by minimizing the interference from additives.Herein,we construct a freestanding cathode composed of MoS_(3)/PPy nanowires(NWs)deposited on porous nickel foam(NF)(MoS_(3)/PPy/NF)through electrochemical methods,which can work efficiently as sulfur-equivalent cathode material for Li-S batteries.The structural stability of the MoS_(3)/PPy/NF cathode is greatly enhanced due to its significant tolerance to the volume expansion of MoS_(3)during the lithiation process,which we ascribe to the flexible 3D framework of PPy NWs,leading to superior cycling performance compared to the bulk-MoS_(3)/NF reference.Eliminating the interference of binder and carbon additives,the evolution of the chemical and electronic structure of Mo and S species during the discharge/charge was studied by X-ray absorption near-edge spectroscopy(XANES).The formation of lithium polysulfides was excluded as the driving cathode reaction mechanism,suggesting the great potential of MoS_(3)as a promising sulfur-equivalent cathode material to evade the shuttle effect for Li-S batteries.The present study successfully demonstrates the importance of structural design of freestanding electrode enhancing the cycling performances and revealing the corresponding mechanisms.展开更多
Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is cr...Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of PEMFC.In this paper,a PEMFC with the threechannel serpentine flow field was used and studied.The different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions,respectively.And then,the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical performance.The test results show that the assembly bolt torque significantly affected the electrochemical performance of the PEMFC.In uniform assembly bolt torque conditions,the maximal power density increased initially as the assembly bolt torque increased,and then decreased on further increasing the assembly torque.It existed the optimum assembly torque which was found to be 3.0 N·m in this work.In non-uniform assembly clamping bolt torque conditions,the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·m.This could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst layers.This work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.展开更多
To address climate change and promote environmental sustainability,electrochemical energy conversion and storage systems emerge as promising alternative to fossil fuels,catering to the escalating demand for energy.Ach...To address climate change and promote environmental sustainability,electrochemical energy conversion and storage systems emerge as promising alternative to fossil fuels,catering to the escalating demand for energy.Achieving optimal energy efficiency and cost competitiveness in these systems requires the strategic design of electrocatalysts,coupled with a thorough comprehension of the underlying mechanisms and degradation behavior occurring during the electrocatalysis processes.Scanning electrochemical microscopy(SECM),an analytical technique for studying surface electrochemically,stands out as a powerful tool offering electrochemical insights.It possesses remarkable spatiotemporal resolution,enabling the visualization of the localized electrochemical activity and surface topography.This review compiles crucial research findings and recent breakthroughs in electrocatalytic processes utilizing the SECM methodology,specifically focusing on applications in electrolysis,fuel cells,and metal–oxygen batteries within the realm of energy conversion and storage systems.Commencing with an overview of each energy system,the review introduces the fundamental principles of SECM,and aiming to provide new perspectives and broadening the scope of applied research by describing the major research categories within SECM.展开更多
Biphasic layered oxide cathodes,known for their superior electrochemical performance,are prime candidates for commercializing in Na-ion batteries.Herein,we unveil a series of P3/P2 monophasic and biphasic Al-substitut...Biphasic layered oxide cathodes,known for their superior electrochemical performance,are prime candidates for commercializing in Na-ion batteries.Herein,we unveil a series of P3/P2 monophasic and biphasic Al-substituted Na_(3/4)Mn_(5-x/8)Al_(2x/8)Ni_(3-x/8)O_(2)layered oxide cathodes that lie along the‘zero Mn^(3+)line’in the Na_(3/4)(Mn-Al-Ni)O_(2)pseudo-ternary system.The structural analysis showed a larger Na^(+)conduction bottleneck area in both P3 and P2 structures with a higher Al3+content,which enhanced their rate performance.In each composition,the P3/P2 biphasic compound with nearly equal fractions of P3 and P2 phases outperformed their monophasic counterparts in almost all electrochemical performance parameters.Operando synchrotron XRD measurements obtained for the monophasic P3 and biphasic P2/P3 samples revealed the absence of the O3 phase during cycling.The high structure stability and faster Na^(+)transport kinetics in the biphasic samples underpins the enhancement of electrochemical properties in the Al-substituted P3/P2 cathodes.These results highlight fixed oxidation state lines as a novel tool to identify and design layered oxide cathodes for Na-ion batteries in pseudo-ternary diagrams involving Jahn-Teller active cations.展开更多
Constructing the magnesium alloy with fine grains,low density of dislocations,and weak crystal orientation is of crucial importance to enhance its comprehensive performance as the anode for Mg-air battery.However,this...Constructing the magnesium alloy with fine grains,low density of dislocations,and weak crystal orientation is of crucial importance to enhance its comprehensive performance as the anode for Mg-air battery.However,this unique microstructure can hardly be achieved with conventional plastic deformation such as rolling or extrusion.Herein,we tailor the microstructure of Mg-Al-Sn-RE alloy by using the friction stir processing,which obviously refines the grains without increasing dislocation density or strengthening crystal orientation.The Mg-air battery with the processed Mg-Al-Sn-RE alloy as the anode exhibits higher discharge voltages and capacities than that employing the untreated anode.Furthermore,the impact of friction stir processing on the electrochemical discharge behaviour of Mg-Al-Sn-RE anode and the corresponding mechanism are also analysed according to microstructure characterization and electrochemical response.展开更多
In vivo monitoring of animal physiological information plays a crucial role in promptly alerting humans to potential diseases in animals and aiding in the exploration of mechanisms underlying human diseases.Currently,...In vivo monitoring of animal physiological information plays a crucial role in promptly alerting humans to potential diseases in animals and aiding in the exploration of mechanisms underlying human diseases.Currently,implantable electrochemical microsensors have emerged as a prominent area of research.These microsensors not only fulfill the technical requirements for monitoring animal physiological information but also offer an ideal platform for integration.They have been extensively studied for their ability to monitor animal physiological information in a minimally invasive manner,characterized by their bloodless,painless features,and exceptional performance.The development of implantable electrochemical microsensors for in vivo monitoring of animal physiological information has witnessed significant scientific and technological advancements through dedicated efforts.This review commenced with a comprehensive discussion of the construction of microsensors,including the materials utilized and the methods employed for fabrication.Following this,we proceeded to explore the various implantation technologies employed for electrochemical microsensors.In addition,a comprehensive overview was provided of the various applications of implantable electrochemical microsensors,specifically in the monitoring of diseases and the investigation of disease mechanisms.Lastly,a concise conclusion was conducted on the recent advancements and significant obstacles pertaining to the practical implementation of implantable electrochemical microsensors.展开更多
Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.H...Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.Here,we report an atomically ordered intermetallic pallium-zinc(PdZn)electrocatalyst comprising a high density of PdZn pairs for boosting urea electrosynthesis.It is found that Pd and Zn are responsible for the adsorption and activation of NO_(3)^(-)and CO_(2),respectively,and thus the co-adsorption and co-activation NO_(3)^(-)and CO_(2) are achieved in ordered PdZn pairs.More importantly,the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C-N coupling with a low kinetical barrier,as demonstrated on both operando measurements and theoretical calculations.Consequently,the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78%and a urea yield rate of 1274.42μg mg^(-1) h^(-1),and the latter is 1.5-fold larger than disordered pairs in PdZn alloys.This work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs.展开更多
The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was syn...The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was synthesized by high temperature solid-state method, taking the Mg element as a doping element and the spherical Ni<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> (OH)<sub>2</sub>, Li<sub>2</sub>CO<sub>3</sub> as raw materials. The effects of calcination temperature on the structure and properties of the products were investigated. The structure and morphology of cathode materials powder were analyzed by X-ray diffraction spectroscopy (XRD) and scanning electronmicroscopy (SEM). The electrochemical properties of the cathode materials were studied by charge-discharge test and cyclic properties test. The results show that LiNi<sub>0.4985</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> Mg<sub>0.0015</sub>O<sub>2</sub> cathode material prepared at calcination temperature 930°C has a good layered structure, and the compacted density of the electrode sheet is above 3.68 g/cm<sup>3</sup>. The discharge capacity retention rate is more than 97.5% after 100 cycles at a charge-discharge rate of 1C, displaying a good cyclic performance.展开更多
Lithium recovery from end-of-life Li-ion batteries(LIBs)through pyro-and hydrometallurgical recycling processes involves several refining stages,with high consumption of reagents and energy.A competitive technological...Lithium recovery from end-of-life Li-ion batteries(LIBs)through pyro-and hydrometallurgical recycling processes involves several refining stages,with high consumption of reagents and energy.A competitive technological alternative is the electrochemical oxidation of the cathode materials,whereby lithium can be deintercalated and transferred to an electrolyte solution without the aid of chemical extracting compounds.This article investigates the potential to selectively recover Li from LIB cathode materials by direct electrochemical extraction in aqueous solutions.The process allowed to recovering up to 98%of Li from high-purity commercial cathode materials(LiMn_(2)O_(4),LiCoO_(2),and Li Ni_(1/3)Mn_(1/3)Co_(1/3)O_(2))with a faradaic efficiency of 98%and negligible co-extraction of Co,Ni,and Mn.The process was then applied to recover Li from the real waste LIBs black mass obtained by the physical treatment of electric vehicle battery packs.This black mass contained graphite,conductive carbon,and metal impurities from current collectors and steel cases,which significantly influenced the evolution and performances of Li electrochemical extraction.Particularly,due to concomitant oxidation of impurities,lithium extraction yields and faradaic efficiencies were lower than those obtained with high-purity cathode materials.Copper oxidation was found to occur within the voltage range investigated,but it could not quantitatively explain the reduced Li extraction performances.In fact,a detailed investigation revealed that above 1.3 V vs.Ag/Ag Cl,conductive carbon can be oxidized,contributing to the decreased Li extraction.Based on the reported experimental results,guidelines were provided that quantitatively enable the extraction of Li from the black mass,while preventing the simultaneous oxidation of impurities and,consequently,reducing the energy consumption of the proposed Li recovery method.展开更多
基金The authors acknowledge support from the German Research Foundation(DFG:LE 2249/5-1)the Sino-German Center for Research Promotion(GZ1579)+1 种基金Yunnan Fundamental Research Projects(202201AW070014)Jiajia Qiu and Yu Duan appreciate support from the China Scholarship Council(No.201908530218&202206990027).
文摘Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical energy stor-age devices at all technology readiness levels.Due to various challenging issues,especially limited stability,nano-and micro-structured(NMS)electrodes undergo fast electrochemical performance degradation.The emerging NMS scaffold design is a pivotal aspect of many electrodes as it endows them with both robustness and electrochemical performance enhancement,even though it only occupies comple-mentary and facilitating components for the main mechanism.However,extensive efforts are urgently needed toward optimizing the stereoscopic geometrical design of NMS scaffolds to minimize the volume ratio and maximize their functionality to fulfill the ever-increasing dependency and desire for energy power source supplies.This review will aim at highlighting these NMS scaffold design strategies,summariz-ing their corresponding strengths and challenges,and thereby outlining the potential solutions to resolve these challenges,design principles,and key perspectives for future research in this field.Therefore,this review will be one of the earliest reviews from this viewpoint.
基金supported by the National Research Foundation of Korea(No.2021R1A2B5B03001691).
文摘Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(NRF,2021R1C1C1013953,2022K1A4A7A04094394,2022K1A4A7A04095890)。
文摘The electrochemical reduction of carbon dioxide offers a sound and economically viable technology for the electrification and decarbonization of the chemical and fuel industries.In this technology,an electrocatalytic material and renewable energy-generated electricity drive the conversion of carbon dioxide into high-value chemicals and carbon-neutral fuels.Over the past few years,single-atom catalysts have been intensively studied as they could provide near-unity atom utilization and unique catalytic performance.Single-atom catalysts have become one of the state-of-the-art catalyst materials for the electrochemical reduction of carbon dioxide into carbon monoxide.However,it remains a challenge for single-atom catalysts to facilitate the efficient conversion of carbon dioxide into products beyond carbon monoxide.In this review,we summarize and present important findings and critical insights from studies on the electrochemical carbon dioxide reduction reaction into hydrocarbons and oxygenates using single-atom catalysts.It is hoped that this review gives a thorough recapitulation and analysis of the science behind the catalysis of carbon dioxide into more reduced products through singleatom catalysts so that it can be a guide for future research and development on catalysts with industry-ready performance for the electrochemical reduction of carbon dioxide into high-value chemicals and carbon-neutral fuels.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) (Grant Nos.2018R1A6A1A03024334,2019R1A2C1007637,2021M3I3A1082880,2021R1I1A1A01044174)the Basic Science Research Capacity Enhancement Project through Korea Basic Science Institute (Grant No.2019R1A6C1010024)。
文摘The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes(GDE),and the effect of nitrogen(N)doping on the ECR activity of ZnO electrocatalysts was investigated.Initially,a ZnO nanosheet was prepared via the hydrothermal method,and nitridation was performed at different times to control the N-doping content.With an increase in the N-doping content,the morphological properties of the nanosheet changed significantly,namely,the 2D nanosheets transformed into irregularly shaped nanoparticles.Furthermore,the ECR performance of Zn O electrocatalysts with different N-doping content was assessed in 1.0 M KHCO_(3) electrolyte using a gas-diffusion electrode-based ECR cell.While the ECR activity increased after a small amount of N doping,it decreased for higher N doping content.Among them,the N:ZnO-1 h electrocatalysts showed the best CO selectivity,with a faradaic efficiency(FE_(CO))of 92.7%at-0.73 V vs.reversible hydrogen electrode(RHE),which was greater than that of an undoped Zn O electrocatalyst(FE_(CO)of 63.4%at-0.78 V_(RHE)).Also,the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h,with a partial current density of-92.1 mA cm^(-2).This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations,demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from(ⅰ)the optimized active sites lowering the free energy barrier for the rate-determining step(RDS),and(ⅱ)the modification of electronic structure enhancing the electron transfer rate by N doping.
基金supported in part by the National Natural Science Foundation of China(Nos.22075027,52003030)Starting Grant from Beijing Institute of Technology and financial support from the State Key Laboratory of Explosion Science and Technology(YBKT21-06,YKBT23-05).
文摘Aqueous zinc-ion batteries(AZIBs)are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability.In response to the growing demand for green and sustainable energy storage solutions,organic electrodes with the scalability from inexpensive starting materials and potential for biodegradation after use have become a prominent choice for AZIBs.Despite gratifying progresses of organic molecules with electrochemical performance in AZIBs,the research is still in infancy and hampered by certain issues due to the underlying complex electrochemistry.Strategies for designing organic electrode materials for AZIBs with high specific capacity and long cycling life are discussed in detail in this review.Specifically,we put emphasis on the unique electrochemistry of different redox-active structures to provide in-depth understanding of their working mechanisms.In addition,we highlight the importance of molecular size/dimension regarding their profound impact on electrochemical performances.Finally,challenges and perspectives are discussed from the developing point of view for future AZIBs.We hope to provide a valuable evaluation on organic electrode materials for AZIBs in our context and give inspiration for the rational design of high-performance AZIBs.
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of China,China(Grant No.21975082 and 21736003)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472 and 2022A1515011341)the Science and Technology Program of Guangzhou(Grant Number:202102080479).
文摘In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.
文摘For the challenging nature of the zirconium environment analysis, this study consists to analyze the electrochemical behavior of Zirconium in both aqueous and organic media. To that end first the electrolytic media was selected on the basis of the Pourbaix potential-pH diagram, which provides informations on the predominance of Zr<sup>(IV) </sup> ion and Zr in aqueous media. In aqueous media, analyzes were first carried out in acidic media then in basic media. Studies have thus revealed that the acidic environment is not favourable for the electrochemical analysis of zirconium. Voltammograms obtained in an acidic environment show no zirconium detection signal;this is due to the strong presence of H<sup>+</sup> ions in the solution. We have also observed in acidic media the phenomenon of passivation of the electrode surface. In aqueous alkaline media (pH = 13), we have drawn in reduction several Intensity-Potential curves by fixingsome technical parameterslike scanning speed, rotation speed of the electrode. The obtained voltammograms show cathodic waves, starting from -1.5 V/DHW and attributed to the reduction of Zr<sup> (IV) </sup> to Zr (0). The last phase of this study focused on the electrochemical analysis of zirconium in an organic media. In this media, several intensity-potential curves were plotted in reduction and in cyclic voltammetry with various parameters. Through several reduction analysis, the Zr<sup> (IV) </sup> was reduced to Zr (0) to the potential of -1.5 V/DHW. The electrochemical analysis of zirconium in organic media seems globally easier to achieve thanks to its large solvent window (i.e. dimethylformamide (DMF) solvent window > 6 V).
基金supported by the National Key Research and Development Program of China(2021YFC2103300)the National Natural Science Foundation of China(22078148)the Natural Science Foundation of Jiangsu Province(BK20220002).
文摘Dissolved oxygen(DO)usually refers to the amount of oxygen dissolved in water.In the environment,medicine,and fermentation industries,the DO level needs to be accurate and capable of online monitoring to guide the precise control of water quality,clinical treatment,and microbial metabolism.Compared with other analytical methods,the electrochemical strategy is superior in its fast response,low cost,high sensitivity,and portable device.However,an electrochemical DO sensor faces a trade-off between sensitivity and long-term stability,which strongly limits its practical applications.To solve this problem,various advanced nanomaterials have been proposed to promote detection performance owing to their excellent electrocatalysis,conductivity,and chemical stability.Therefore,in this review,we focus on the recent progress of advanced nanomaterial-based electrochemical DO sensors.Through the comparison of the working principles on the main analysis techniques toward DO,the advantages of the electrochemical method are discussed.Emphasis is placed on recently developed nanomaterials that exhibit special characteristics,including nanostructures and preparation routes,to benefit DO determination.Specifically,we also introduce some interesting research on the configuration design of the electrode and device,which is rarely introduced.Then,the different requirements of the electrochemical DO sensors in different application fields are included to provide brief guidance on the selection of appropriate nanomaterials.Finally,the main challenges are evaluated to propose future development prospects and detection strategies for nanomaterial-based electrochemical sensors.
基金financial support provided by Projects(no.2020CDJXZ001)the Fundamental Research Funds for the Central Universities+1 种基金the Technology Innovation and Application Development Special Project of Chongqing(Z20211350 and Z20211351)Scientific Research Project of Chongqing Ecological Environment Bureau(no.CQEE2022-STHBZZ118)。
文摘The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy storage.Unfortunately,the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity,which seriously limit the application of Mg-based materials in supercapacitors.Herein,in this review,more than 70 research papers published in recent 10 years were collected and analyzed.Some representative research works were selected,and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were discussed.The effects of various regulative strategies(such as constructing nanostructures,synthesizing composites,defect engineering,and binder-free synthesis,etc.)on the electrochemical performance and their mechanism are demonstrated using spinelstructured MgX_(2)O_(4) and layered structured Mg-X-LDHs as examples.In addition,the application of magnesium oxide and magnesium hydroxide in electrode materials,MXene's solid spacers and hard templates are introduced.Finally,the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.
基金China Scholarship Council,Grant/Award Number:201806950083Advanced Materials research program of the Zernike National Research CentreFaculty of Science and Engineering(FSE),University of Groningen。
文摘The development of lithium-sulfur(Li-S)batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge.Herein,the crystallinities of a titanium nitride(TiN)film on copper-embedded carbon nanofibers(Cu-CNFs)are regulated and the nanofibers are used as interlayers to resolve the aforementioned crucial issues.A low-crystalline TiN-coated Cu-CNF(L-TiN-Cu-CNF)interlayer is compared with its highly crystalline counterpart(H-TiN-Cu-CNFs).It is demonstrated that the L-TiN coating not only strengthens the chemical adsorption toward polysulfides but also greatly accelerates the electrochemical conversion of polysulfides.Due to robust carbon frameworks and enhanced kinetics,impressive highrate performance at 2 C(913 mAh g^(-1)based on sulfur)as well as remarkable cyclic stability up to 300 cycles(626 mAh g^(-1))with capacity retention of 46.5%is realized for L-TiN-Cu-CNF interlayer-configured Li-S batteries.Even under high loading(3.8 mg cm^(-2))of sulfur and relatively lean electrolyte(10μL electrolyte per milligram sulfur)conditions,the Li-S battery equipped with L-TiN-Cu-CNF interlayers delivers a high capacity of 1144 mAh g^(-1)with cathodic capacity of 4.25 mAh cm^(-2)at 0.1 C,providing a potential pathway toward the design of multifunctional interlayers for highly efficient Li-S batteries.
文摘The durability of reinforced concrete structures is greatly influenced by the corrosion of the reinforcement. In addition to air pollution related to the repair of corroded structures, chloride ions are the main factors of corrosion of reinforced concrete structures. This study aims to valorize a clay inhibitor against reinforcement corrosion in reinforced concrete. This clay (Attapulgite) was incorporated into reinforced concretes at different percentages of substitution of calcined attapulgite (0%, 5% and 10%) to cement in the formulation. The corrosion inhibitory power of attapulgite is evaluated in reinforced concretes subjected to the action of chloride ions at different intervals in the NaCl solution (1 day, 21 days and 45 days) by electrochemical methods (zero current chronopotentiometry, polarization curves and electrochemical impedance spectroscopy). This study showed that in the presence of chloride ions, the composition based on 10% attapulgite has an appreciable inhibitory effect with an average inhibitory efficiency of 82%.
基金supported by the National Science Foundation for Young Scientists of China(21704040)the financial support of the Helmholtz AssociationOpen Access funding enabled and organized by Projekt DEAL
文摘The development of freestanding and binder-free electrode is an effective approach to perform the inherent capacity of active materials and promote the mechanism study by minimizing the interference from additives.Herein,we construct a freestanding cathode composed of MoS_(3)/PPy nanowires(NWs)deposited on porous nickel foam(NF)(MoS_(3)/PPy/NF)through electrochemical methods,which can work efficiently as sulfur-equivalent cathode material for Li-S batteries.The structural stability of the MoS_(3)/PPy/NF cathode is greatly enhanced due to its significant tolerance to the volume expansion of MoS_(3)during the lithiation process,which we ascribe to the flexible 3D framework of PPy NWs,leading to superior cycling performance compared to the bulk-MoS_(3)/NF reference.Eliminating the interference of binder and carbon additives,the evolution of the chemical and electronic structure of Mo and S species during the discharge/charge was studied by X-ray absorption near-edge spectroscopy(XANES).The formation of lithium polysulfides was excluded as the driving cathode reaction mechanism,suggesting the great potential of MoS_(3)as a promising sulfur-equivalent cathode material to evade the shuttle effect for Li-S batteries.The present study successfully demonstrates the importance of structural design of freestanding electrode enhancing the cycling performances and revealing the corresponding mechanisms.
基金Supported by National Natural Science Foundation of China (Grant No.52275152)。
文摘Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of PEMFC.In this paper,a PEMFC with the threechannel serpentine flow field was used and studied.The different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions,respectively.And then,the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical performance.The test results show that the assembly bolt torque significantly affected the electrochemical performance of the PEMFC.In uniform assembly bolt torque conditions,the maximal power density increased initially as the assembly bolt torque increased,and then decreased on further increasing the assembly torque.It existed the optimum assembly torque which was found to be 3.0 N·m in this work.In non-uniform assembly clamping bolt torque conditions,the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·m.This could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst layers.This work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.
基金supported by a characterization platform for advanced materials funded by the Korea Research Institute of Standards and Science(KRISS-2023-GP2023-0014)the KRISS(Korea Research Institute of Standards and Science)MPI Lab.program。
文摘To address climate change and promote environmental sustainability,electrochemical energy conversion and storage systems emerge as promising alternative to fossil fuels,catering to the escalating demand for energy.Achieving optimal energy efficiency and cost competitiveness in these systems requires the strategic design of electrocatalysts,coupled with a thorough comprehension of the underlying mechanisms and degradation behavior occurring during the electrocatalysis processes.Scanning electrochemical microscopy(SECM),an analytical technique for studying surface electrochemically,stands out as a powerful tool offering electrochemical insights.It possesses remarkable spatiotemporal resolution,enabling the visualization of the localized electrochemical activity and surface topography.This review compiles crucial research findings and recent breakthroughs in electrocatalytic processes utilizing the SECM methodology,specifically focusing on applications in electrolysis,fuel cells,and metal–oxygen batteries within the realm of energy conversion and storage systems.Commencing with an overview of each energy system,the review introduces the fundamental principles of SECM,and aiming to provide new perspectives and broadening the scope of applied research by describing the major research categories within SECM.
基金the Science and Engineering Research Board(SERB),Govt.of India,for the financial support(grant number:CRG/2021/005548).
文摘Biphasic layered oxide cathodes,known for their superior electrochemical performance,are prime candidates for commercializing in Na-ion batteries.Herein,we unveil a series of P3/P2 monophasic and biphasic Al-substituted Na_(3/4)Mn_(5-x/8)Al_(2x/8)Ni_(3-x/8)O_(2)layered oxide cathodes that lie along the‘zero Mn^(3+)line’in the Na_(3/4)(Mn-Al-Ni)O_(2)pseudo-ternary system.The structural analysis showed a larger Na^(+)conduction bottleneck area in both P3 and P2 structures with a higher Al3+content,which enhanced their rate performance.In each composition,the P3/P2 biphasic compound with nearly equal fractions of P3 and P2 phases outperformed their monophasic counterparts in almost all electrochemical performance parameters.Operando synchrotron XRD measurements obtained for the monophasic P3 and biphasic P2/P3 samples revealed the absence of the O3 phase during cycling.The high structure stability and faster Na^(+)transport kinetics in the biphasic samples underpins the enhancement of electrochemical properties in the Al-substituted P3/P2 cathodes.These results highlight fixed oxidation state lines as a novel tool to identify and design layered oxide cathodes for Na-ion batteries in pseudo-ternary diagrams involving Jahn-Teller active cations.
基金The Authors acknowledge the financial support of the National Nature Science Foundation of China(No.52171067)the Natural Science Foundation of Guangdong Province of China(No.2022A1515012366).
文摘Constructing the magnesium alloy with fine grains,low density of dislocations,and weak crystal orientation is of crucial importance to enhance its comprehensive performance as the anode for Mg-air battery.However,this unique microstructure can hardly be achieved with conventional plastic deformation such as rolling or extrusion.Herein,we tailor the microstructure of Mg-Al-Sn-RE alloy by using the friction stir processing,which obviously refines the grains without increasing dislocation density or strengthening crystal orientation.The Mg-air battery with the processed Mg-Al-Sn-RE alloy as the anode exhibits higher discharge voltages and capacities than that employing the untreated anode.Furthermore,the impact of friction stir processing on the electrochemical discharge behaviour of Mg-Al-Sn-RE anode and the corresponding mechanism are also analysed according to microstructure characterization and electrochemical response.
基金the Fundamental Research Funds for the Central Universities,National Natural Science Foundation of China(No.82302345).
文摘In vivo monitoring of animal physiological information plays a crucial role in promptly alerting humans to potential diseases in animals and aiding in the exploration of mechanisms underlying human diseases.Currently,implantable electrochemical microsensors have emerged as a prominent area of research.These microsensors not only fulfill the technical requirements for monitoring animal physiological information but also offer an ideal platform for integration.They have been extensively studied for their ability to monitor animal physiological information in a minimally invasive manner,characterized by their bloodless,painless features,and exceptional performance.The development of implantable electrochemical microsensors for in vivo monitoring of animal physiological information has witnessed significant scientific and technological advancements through dedicated efforts.This review commenced with a comprehensive discussion of the construction of microsensors,including the materials utilized and the methods employed for fabrication.Following this,we proceeded to explore the various implantation technologies employed for electrochemical microsensors.In addition,a comprehensive overview was provided of the various applications of implantable electrochemical microsensors,specifically in the monitoring of diseases and the investigation of disease mechanisms.Lastly,a concise conclusion was conducted on the recent advancements and significant obstacles pertaining to the practical implementation of implantable electrochemical microsensors.
基金supported by the National Natural Science Foundation of China(22379100,U21A20312)the Shenzhen Science and Technology Program(Grant No.20231121200418001)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2022B1515120084)the Key Project of Department of Education of Guangdong Province(2023ZDZX3020)。
文摘Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained limited.Here,we report an atomically ordered intermetallic pallium-zinc(PdZn)electrocatalyst comprising a high density of PdZn pairs for boosting urea electrosynthesis.It is found that Pd and Zn are responsible for the adsorption and activation of NO_(3)^(-)and CO_(2),respectively,and thus the co-adsorption and co-activation NO_(3)^(-)and CO_(2) are achieved in ordered PdZn pairs.More importantly,the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C-N coupling with a low kinetical barrier,as demonstrated on both operando measurements and theoretical calculations.Consequently,the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78%and a urea yield rate of 1274.42μg mg^(-1) h^(-1),and the latter is 1.5-fold larger than disordered pairs in PdZn alloys.This work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs.
文摘The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was synthesized by high temperature solid-state method, taking the Mg element as a doping element and the spherical Ni<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> (OH)<sub>2</sub>, Li<sub>2</sub>CO<sub>3</sub> as raw materials. The effects of calcination temperature on the structure and properties of the products were investigated. The structure and morphology of cathode materials powder were analyzed by X-ray diffraction spectroscopy (XRD) and scanning electronmicroscopy (SEM). The electrochemical properties of the cathode materials were studied by charge-discharge test and cyclic properties test. The results show that LiNi<sub>0.4985</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> Mg<sub>0.0015</sub>O<sub>2</sub> cathode material prepared at calcination temperature 930°C has a good layered structure, and the compacted density of the electrode sheet is above 3.68 g/cm<sup>3</sup>. The discharge capacity retention rate is more than 97.5% after 100 cycles at a charge-discharge rate of 1C, displaying a good cyclic performance.
基金the Horizon Europe Project“Batteries reuse and direct production of high performances cathodic and anodic materials and other raw materials from batteries recycling using low cost and environmentally friendly technologies” (RHINOCEROS project,grant no.101069685)。
文摘Lithium recovery from end-of-life Li-ion batteries(LIBs)through pyro-and hydrometallurgical recycling processes involves several refining stages,with high consumption of reagents and energy.A competitive technological alternative is the electrochemical oxidation of the cathode materials,whereby lithium can be deintercalated and transferred to an electrolyte solution without the aid of chemical extracting compounds.This article investigates the potential to selectively recover Li from LIB cathode materials by direct electrochemical extraction in aqueous solutions.The process allowed to recovering up to 98%of Li from high-purity commercial cathode materials(LiMn_(2)O_(4),LiCoO_(2),and Li Ni_(1/3)Mn_(1/3)Co_(1/3)O_(2))with a faradaic efficiency of 98%and negligible co-extraction of Co,Ni,and Mn.The process was then applied to recover Li from the real waste LIBs black mass obtained by the physical treatment of electric vehicle battery packs.This black mass contained graphite,conductive carbon,and metal impurities from current collectors and steel cases,which significantly influenced the evolution and performances of Li electrochemical extraction.Particularly,due to concomitant oxidation of impurities,lithium extraction yields and faradaic efficiencies were lower than those obtained with high-purity cathode materials.Copper oxidation was found to occur within the voltage range investigated,but it could not quantitatively explain the reduced Li extraction performances.In fact,a detailed investigation revealed that above 1.3 V vs.Ag/Ag Cl,conductive carbon can be oxidized,contributing to the decreased Li extraction.Based on the reported experimental results,guidelines were provided that quantitatively enable the extraction of Li from the black mass,while preventing the simultaneous oxidation of impurities and,consequently,reducing the energy consumption of the proposed Li recovery method.