Pub Date : 2025-02-27DOI: 10.1016/j.electacta.2025.145945
Rui Liu , Shuhui Li , Zheng Wang, Huidong Xu, Weihuang Wang, Yixin Jia, Lantian Zhang, Zicheng Xie, Liangbing Wang
Reducing size of Na3V2(PO4)3 (NVP) into nanoscale is regarded as an effective way to improve its high-rate performance for sodium-ion storage. However, the current synthetic approaches for nanostructured NVP such as sol-gel, hydrothermal, and electrospinning still possess limitations in terms of long reaction time and complicated operation. Here, we combine high-boiling organic solvent-assisted colloidal synthesis (HOS-CS) and calcination to fabricate carbon-coated NVP nanoparticles (NPs) with the size of about 50 nm distributed in carbon nanotubes scaffolds as the cathode for SIBs. This HOS-CS strategy demonstrates unique merit of short synthetic period, solving the problem of previously-known approaches in the aspect of synthetic efficiency. Impressively, NVP@C@MWCNTs offers up to 108.6 mAh g-1 at 0.5 C, and also achieves 83.67 and 67.6 mAh g-1 of initial capacities nearly 80 % and 76.1 % of retention after 3000 cycles at ultrahigh rates of 30 C and 50 C, respectively. More surprisingly, the NVP@C@MWCNTs cathode is matched with the hard carbon (HC) anode to construct NVP@C@MWCNTs||HC full cell, delivering as high as 71 mAh g-1 of initial capacity with 72.8 % of retention after 500 cycles even at 10 C. This work provides an efficient strategy for synthesizing high-rate-capability NVP-based cathode towards fast chargeable SIBs.
{"title":"Carbon decorated Na3V2(PO4)3 nanoparticles as a high-rate-capability cathode for fast chargeable sodium-ion batteries","authors":"Rui Liu , Shuhui Li , Zheng Wang, Huidong Xu, Weihuang Wang, Yixin Jia, Lantian Zhang, Zicheng Xie, Liangbing Wang","doi":"10.1016/j.electacta.2025.145945","DOIUrl":"10.1016/j.electacta.2025.145945","url":null,"abstract":"<div><div>Reducing size of Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> (NVP) into nanoscale is regarded as an effective way to improve its high-rate performance for sodium-ion storage. However, the current synthetic approaches for nanostructured NVP such as sol-gel, hydrothermal, and electrospinning still possess limitations in terms of long reaction time and complicated operation. Here, we combine high-boiling organic solvent-assisted colloidal synthesis (HOS-CS) and calcination to fabricate carbon-coated NVP nanoparticles (NPs) with the size of about 50 nm distributed in carbon nanotubes scaffolds as the cathode for SIBs. This HOS-CS strategy demonstrates unique merit of short synthetic period, solving the problem of previously-known approaches in the aspect of synthetic efficiency. Impressively, NVP@C@MWCNTs offers up to 108.6 mAh g<sup>-1</sup> at 0.5 C, and also achieves 83.67 and 67.6 mAh g<sup>-1</sup> of initial capacities nearly 80 % and 76.1 % of retention after 3000 cycles at ultrahigh rates of 30 C and 50 C, respectively. More surprisingly, the NVP@C@MWCNTs cathode is matched with the hard carbon (HC) anode to construct NVP@C@MWCNTs||HC full cell, delivering as high as 71 mAh g<sup>-1</sup> of initial capacity with 72.8 % of retention after 500 cycles even at 10 C. This work provides an efficient strategy for synthesizing high-rate-capability NVP-based cathode towards fast chargeable SIBs.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"522 ","pages":"Article 145945"},"PeriodicalIF":5.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-27DOI: 10.1016/j.electacta.2025.145943
E. Bluett, J. Edy, M. Dodd, A.C.A. de Vooys, N. Wint, E. Jewell, H.N. McMurray
This paper describes a systematic study into the initiation and propagation of filiform corrosion (FFC) on industrially important Cr(III) coatings applied to packaging steel. FFC was initiated by introducing an artificial scribe into a model PVB organic coating which had been applied to the metallic coatings. The FFC corroded area was shown to decrease at increased values of Cr(III) oxide coating weight. This was explained largely due to the insulating properties of Cr(III) oxide. Chloride entrapment within the tail caused filament tapering. FFC was shown not to initiate on traditional electro chromium coated steel (ECCS).
{"title":"The influence of chromium oxide coating weight on filiform corrosion of trivalent chromium coatings for packaging steel","authors":"E. Bluett, J. Edy, M. Dodd, A.C.A. de Vooys, N. Wint, E. Jewell, H.N. McMurray","doi":"10.1016/j.electacta.2025.145943","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145943","url":null,"abstract":"This paper describes a systematic study into the initiation and propagation of filiform corrosion (FFC) on industrially important Cr(III) coatings applied to packaging steel. FFC was initiated by introducing an artificial scribe into a model PVB organic coating which had been applied to the metallic coatings. The FFC corroded area was shown to decrease at increased values of Cr(III) oxide coating weight. This was explained largely due to the insulating properties of Cr(III) oxide. Chloride entrapment within the tail caused filament tapering. FFC was shown not to initiate on traditional electro chromium coated steel (ECCS).","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"42 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145902
Soojin Lee, Ju-Yul Lee, Yangdo Kim, Seil Kim
This study entailed the development of a novel acidic silver-plating solution using phosphorus-based compounds. A systematic investigation was conducted to optimize the effects of the complexing agents tris(hydroxypropyl)phosphine (THPP), pyrophosphoric acid (PPA), and phosphoric acid (PA) electrolytes on silver reduction and solution stability. Linear sweep voltammetry demonstrated the stabilizing effect of THPP on Ag ions, revealing cathodic polarization of the Ag reduction potential at [Ag+]:[THPP] ratios ranging from 1:1 to 1:5. Notably, the 1:4 ratio exhibited the lowest reduction potential, indicating that the [Ag(THPP)₄]+ complex formed under these conditions was the most stable, a conclusion supported by density functional theory (DFT) calculations. Furthermore, the optimal concentration of the plating solution was determined by analyzing current density variations with respect to the concentrations of PPA and PA. The Scharifker–Hills model, energy level analysis using DFT, and cyclic voltammetry elucidated the impact of electrolyte–proton interactions in influencing hydrogen evolution, thereby revealing distinct nucleation mechanisms for Ag reduction in each electrolyte. This study establishes a THPP-based acidic plating solution capable of achieving stable Ag deposition under acidic conditions by optimizing the conditions for complexing agents and electrolytes. These findings suggest the possibility of substituting cyanide-based plating solutions in applications requiring silver plating in acidic environments, potentially enhancing precise plating processes such as pattern plating.
{"title":"Electroplating behavior of a phosphorous-based cyanide-free silver electrolyte in an acidic environment","authors":"Soojin Lee, Ju-Yul Lee, Yangdo Kim, Seil Kim","doi":"10.1016/j.electacta.2025.145902","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145902","url":null,"abstract":"This study entailed the development of a novel acidic silver-plating solution using phosphorus-based compounds. A systematic investigation was conducted to optimize the effects of the complexing agents tris(hydroxypropyl)phosphine (THPP), pyrophosphoric acid (PPA), and phosphoric acid (PA) electrolytes on silver reduction and solution stability. Linear sweep voltammetry demonstrated the stabilizing effect of THPP on Ag ions, revealing cathodic polarization of the Ag reduction potential at [Ag<sup>+</sup>]:[THPP] ratios ranging from 1:1 to 1:5. Notably, the 1:4 ratio exhibited the lowest reduction potential, indicating that the [Ag(THPP)₄]<sup>+</sup> complex formed under these conditions was the most stable, a conclusion supported by density functional theory (DFT) calculations. Furthermore, the optimal concentration of the plating solution was determined by analyzing current density variations with respect to the concentrations of PPA and PA. The Scharifker–Hills model, energy level analysis using DFT, and cyclic voltammetry elucidated the impact of electrolyte–proton interactions in influencing hydrogen evolution, thereby revealing distinct nucleation mechanisms for Ag reduction in each electrolyte. This study establishes a THPP-based acidic plating solution capable of achieving stable Ag deposition under acidic conditions by optimizing the conditions for complexing agents and electrolytes. These findings suggest the possibility of substituting cyanide-based plating solutions in applications requiring silver plating in acidic environments, potentially enhancing precise plating processes such as pattern plating.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"15 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145939
Edgardo Maximiliano Gavilán-Arriazu, Andres Ruderman, Francisco Fernandez, Igor Baskin, Roman G. Fedorov, Jonas Schlaier, Sebastian Maletti, Christian Heubner, Alexander Michaelis, Yair Ein-Eli, Ezequiel Pedro Marcos Leiva
We provide a comprehensive approach to a methodology to evaluate the performance of lithium-ion batteries and related intercalation systems at the single-particle level, by constructing diagrammatic representations. The idea that underlies these methodologies is using two dimensionless/scaling parameters, which allow the evaluation of a series of experimental parameters and making predictions in a simple, fast, and visual way. In both cases, the model considers the finite diffusion of ions in materials and the charge transfer at the electrode/electrolyte interface. The present work also aims to bring experimental single-particle measurements and single-particle models closer, providing the theoretical background necessary to deduce these scalable parameters, and may inspire more sophisticated theoretical developments in the future, considering other aspects of the nature of the composites. While revisiting relevant work in the area, the present work presents the following novel features: 1- It introduces new scaling kinetic parameter, which makes the diagrams independent of particle geometry. 2- It defines a new metric to evaluate the performance of electrode materials comparatively in terms of their diffusional and charge transfer properties. 2- It derives analytic limits to the behaviour of the model that are universal, in the sense that they do not depend on the intercalation isotherm of the material. 3- It applies artificial intelligence using a deep neural network trained to approximate the results of physics-based simulations, replicating the theoretical state of charge maps with excellent accuracy.
{"title":"Towards a universal model for assessing the performance of battery materials at the level of single-particle behavior","authors":"Edgardo Maximiliano Gavilán-Arriazu, Andres Ruderman, Francisco Fernandez, Igor Baskin, Roman G. Fedorov, Jonas Schlaier, Sebastian Maletti, Christian Heubner, Alexander Michaelis, Yair Ein-Eli, Ezequiel Pedro Marcos Leiva","doi":"10.1016/j.electacta.2025.145939","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145939","url":null,"abstract":"We provide a comprehensive approach to a methodology to evaluate the performance of lithium-ion batteries and related intercalation systems at the single-particle level, by constructing diagrammatic representations. The idea that underlies these methodologies is using two dimensionless/scaling parameters, which allow the evaluation of a series of experimental parameters and making predictions in a simple, fast, and visual way. In both cases, the model considers the finite diffusion of ions in materials and the charge transfer at the electrode/electrolyte interface. The present work also aims to bring experimental single-particle measurements and single-particle models closer, providing the theoretical background necessary to deduce these scalable parameters, and may inspire more sophisticated theoretical developments in the future, considering other aspects of the nature of the composites. While revisiting relevant work in the area, the present work presents the following novel features: 1- It introduces new scaling kinetic parameter, which makes the diagrams independent of particle geometry. 2- It defines a new metric to evaluate the performance of electrode materials comparatively in terms of their diffusional and charge transfer properties. 2- It derives analytic limits to the behaviour of the model that are universal, in the sense that they do not depend on the intercalation isotherm of the material. 3- It applies artificial intelligence using a deep neural network trained to approximate the results of physics-based simulations, replicating the theoretical state of charge maps with excellent accuracy.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"6 3 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145931
Thays S. Lima , Mauro C. Santos , Artur J. Motheo
This study investigates the electrochemical generation of hydrogen peroxide (H₂O₂) using three distinct cerium oxide nanostructures—nanorods, nanospheres, and nanoparticles—supported on graphene. The nanorods and nanospheres were synthesized via the hydrothermal method, with controlled adjustments to centrifugation speed, calcination temperature, and duration to tailor their morphology. Cerium nanoparticles were prepared using a coprecipitation method. These nanostructures were employed to modify graphene and were evaluated for their performance in H₂O₂ electrogeneration. Among them, cerium nanorods exhibited the highest H₂O₂ production, achieving a 91 % efficiency. This superior performance can be attributed to the presence of oxidizing species (Ce³⁺), as identified through Raman spectroscopy, along with oxygen vacancies and enhanced surface hydrophilicity. Scanning electron microscopy (SEM) revealed that the nanorods were optimally distributed below the graphene sheets. The hydrothermal and coprecipitation synthesis methods proved effective for producing cerium oxide nanostructures with high catalytic activity. These findings highlight the potential of cerium oxide nanostructures as efficient catalysts for wastewater treatment via the electro-Fenton process.
{"title":"Electrochemical generation of hydrogen peroxide using cerium oxide nanostructures supported on graphene: Synthesis, characterization, and application in wastewater treatment","authors":"Thays S. Lima , Mauro C. Santos , Artur J. Motheo","doi":"10.1016/j.electacta.2025.145931","DOIUrl":"10.1016/j.electacta.2025.145931","url":null,"abstract":"<div><div>This study investigates the electrochemical generation of hydrogen peroxide (H₂O₂) using three distinct cerium oxide nanostructures—nanorods, nanospheres, and nanoparticles—supported on graphene. The nanorods and nanospheres were synthesized via the hydrothermal method, with controlled adjustments to centrifugation speed, calcination temperature, and duration to tailor their morphology. Cerium nanoparticles were prepared using a coprecipitation method. These nanostructures were employed to modify graphene and were evaluated for their performance in H₂O₂ electrogeneration. Among them, cerium nanorods exhibited the highest H₂O₂ production, achieving a 91 % efficiency. This superior performance can be attributed to the presence of oxidizing species (Ce³⁺), as identified through Raman spectroscopy, along with oxygen vacancies and enhanced surface hydrophilicity. Scanning electron microscopy (SEM) revealed that the nanorods were optimally distributed below the graphene sheets. The hydrothermal and coprecipitation synthesis methods proved effective for producing cerium oxide nanostructures with high catalytic activity. These findings highlight the potential of cerium oxide nanostructures as efficient catalysts for wastewater treatment via the electro-Fenton process.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"521 ","pages":"Article 145931"},"PeriodicalIF":5.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145933
R. Babilas, J. Bicz, A. Radoń, M. Kądziołka-Gaweł, D. Łukowiec, K. Matus, E. Wyszkowska, Ł. Kurpaska, D. Rudomilova, K. Młynarek-Żak
In this work, the four high entropy CoCrFeNiX alloys (X=Nb,Mo,B,Si) were prepared by induction melting to comparatively analyze their structure, nanomechanical properties, and corrosion resistance. The CoCrFeNiNb and CoCrFeNiMo alloys were composed of FCC solid solution and intermetallic phases (TM)2Nb and Cr-Mo-TM. In the case of the CoCrFeNiB alloy, a complex phase structure was revealed, consisting of FCC solid solution and three types of borides. In turn, the addition of Si substantially altered the phase composition of the CoCrFeNi alloy, resulting in the formation of two intermetallic phases. The corrosion behaviour of the alloys was studied in 3.5 and 5% NaCl solutions. The highest corrosion resistance was characteristic for the CoCrFeNiSi alloy, which showed the most uniform chemical element distribution, showing the lowest corrosion current density and the highest positive corrosion potential values in both environments used. For measurements in a 5% NaCl solution, icorr and Ecorr were equal to 0.24 μA/cm2 and -0.136 V. The least favourable corrosion parameters were recorded for the CoCrFeNiMo alloy. The results of EIS measurements confirmed the high protective abilities of the passive film formed on the CoCrFeNiSi alloy surface. The SKPFM map of the Volta potential differences showed that the Cr-Mo-TM phase with a high molybdenum content was less noble than the FCC solid solution. Similarly, the Ni-rich FCC phase was more noble compared to the (TM)2Nb phase with a high niobium content for the CoCrFeNiNb alloy. The highest strength properties were shown by the alloys with the addition of metalloids. For the CoCrFeNiSi alloy, the highest nanohardness value was obtained (above 15 GPa), while the CoCrFeNiB showed the highest Young modulus (above 275 GPa).
{"title":"Structure, corrosion resistance and nanomechanical properties of CoCrFeNiX (X=Nb,Mo,B,Si) high entropy alloys","authors":"R. Babilas, J. Bicz, A. Radoń, M. Kądziołka-Gaweł, D. Łukowiec, K. Matus, E. Wyszkowska, Ł. Kurpaska, D. Rudomilova, K. Młynarek-Żak","doi":"10.1016/j.electacta.2025.145933","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145933","url":null,"abstract":"In this work, the four high entropy CoCrFeNiX alloys (X=Nb,Mo,B,Si) were prepared by induction melting to comparatively analyze their structure, nanomechanical properties, and corrosion resistance. The CoCrFeNiNb and CoCrFeNiMo alloys were composed of FCC solid solution and intermetallic phases (TM)<sub>2</sub>Nb and Cr-Mo-TM. In the case of the CoCrFeNiB alloy, a complex phase structure was revealed, consisting of FCC solid solution and three types of borides. In turn, the addition of Si substantially altered the phase composition of the CoCrFeNi alloy, resulting in the formation of two intermetallic phases. The corrosion behaviour of the alloys was studied in 3.5 and 5% NaCl solutions. The highest corrosion resistance was characteristic for the CoCrFeNiSi alloy, which showed the most uniform chemical element distribution, showing the lowest corrosion current density and the highest positive corrosion potential values in both environments used. For measurements in a 5% NaCl solution, <em>i</em><sub>corr</sub> and <em>E</em><sub>corr</sub> were equal to 0.24 μA/cm<sup>2</sup> and -0.136 V. The least favourable corrosion parameters were recorded for the CoCrFeNiMo alloy. The results of EIS measurements confirmed the high protective abilities of the passive film formed on the CoCrFeNiSi alloy surface. The SKPFM map of the Volta potential differences showed that the Cr-Mo-TM phase with a high molybdenum content was less noble than the FCC solid solution. Similarly, the Ni-rich FCC phase was more noble compared to the (TM)<sub>2</sub>Nb phase with a high niobium content for the CoCrFeNiNb alloy. The highest strength properties were shown by the alloys with the addition of metalloids. For the CoCrFeNiSi alloy, the highest nanohardness value was obtained (above 15 GPa), while the CoCrFeNiB showed the highest Young modulus (above 275 GPa).","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145922
Xuejiao Chen , Yanwei Li , Qize Huang , Bin Huang , Jinhuan Yao
The synthesis of Prussian blue typically necessitates the incorporation of either K+ or Na+, the resultant Prussian blue analog Cathode materials usually contain either K+ or Na+. In this work, the lithium storage performance of iron-based Prussian blue containing either Na+ (named Na-FeHCF) or K+ (named K-FeHCF) is explored and compared in detail. The results demonstrate that Na-FeHCF significantly outperforms K-FeHCF in terms of reversible capacity, cycling stability, rate capability, and electrochemical reaction kinetics. Na-FeHCF maintains a stable reversible capacity of 84.7 mAh g-1 after 500 cycles at 100 mA g-1, which is two times higher than the corresponding value of the K-FeHCF (35.5 mAh g-1). Ex-situ XRD analysis reveals that Na-FeHCF maintains excellent structure stability during discharge and charge processes, while K-FeHCF undergoes an irreversibly transformations from its original cubic phase to a rhombohedral phase during repeated discharge/charge cycles. The results reported in this work could provide a reference for the structural design and performance optimization of iron-based Prussian blue cathode materials for lithium-ion batteries.
{"title":"Influence of alkali metal ions (Na+/K+) in iron-based Prussian blue frameworks on their lithium storage properties","authors":"Xuejiao Chen , Yanwei Li , Qize Huang , Bin Huang , Jinhuan Yao","doi":"10.1016/j.electacta.2025.145922","DOIUrl":"10.1016/j.electacta.2025.145922","url":null,"abstract":"<div><div>The synthesis of Prussian blue typically necessitates the incorporation of either K<sup>+</sup> or Na<sup>+</sup>, the resultant Prussian blue analog Cathode materials usually contain either K<sup>+</sup> or Na<sup>+</sup>. In this work, the lithium storage performance of iron-based Prussian blue containing either Na<sup>+</sup> (named Na-FeHCF) or K<sup>+</sup> (named K-FeHCF) is explored and compared in detail. The results demonstrate that Na-FeHCF significantly outperforms K-FeHCF in terms of reversible capacity, cycling stability, rate capability, and electrochemical reaction kinetics. Na-FeHCF maintains a stable reversible capacity of 84.7 mAh g<sup>-1</sup> after 500 cycles at 100 mA g<sup>-1</sup>, which is two times higher than the corresponding value of the K-FeHCF (35.5 mAh g<sup>-1</sup>). <em>Ex-situ</em> XRD analysis reveals that Na-FeHCF maintains excellent structure stability during discharge and charge processes, while K-FeHCF undergoes an irreversibly transformations from its original cubic phase to a rhombohedral phase during repeated discharge/charge cycles. The results reported in this work could provide a reference for the structural design and performance optimization of iron-based Prussian blue cathode materials for lithium-ion batteries.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"522 ","pages":"Article 145922"},"PeriodicalIF":5.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145938
Saranda Bakija Alempijević , Kristijan Vidović , Petra Vukosav , Sanja Frka , Ana Kroflič , Ivan Mihaljević , Irena Grgić , Slađana Strmečki
Nitrocatechols (NCs) are hazardous environmental pollutants that pose a significant risk to aquatic organisms. The toxicity of pollutants is determined by their speciation, which depends on interactions with coexisting inorganic and organic substances, emphasizing the need for detailed specific studies. Employing square wave and cyclic voltammetry, we investigated the complexation between NCs, specifically 4-nitrocatechol (4NC), 3-methyl-4-nitrocatechol (3M4NC), 3-methyl-5-nitrocatechol (3M5NC), and 4-methyl-5-nitrocatechol (4M5NC), and copper ions (Cu(II)), a micronutrient that is toxic at elevated concentrations. By confirming and following a quasi-reversible two-electron reduction of di-nitrocatecholate [Cu(NC)2]2- complexes in slightly alkaline solution (pH 8.2), we demonstrated fast complex formation in solution at different analyte concentrations and high kinetic stability. However, the pH lowering resulted in degradation of these complexes, yielding mono-nitrocatecholate [Cu(NC)] species and eventually uncomplexed Cu(II) ions. The chronic toxicity bioassays (AlgaeTox) with Scenedesmus subspicatus microalgae exposed to a mixture of Cu(II) and NCs at different concentrations showed decreased toxicity compared to the toxicity of individual Cu(II) and NCs. This decrease was linked to the formation of [Cu(NC)2]2− complexes, which was confirmed by the appearance of a corresponding voltammetric reduction peak. Conversely, increased toxicity was observed when the complexes were degraded, resulting in the presence of free/labile Cu(II) or NCs species in the solution. These results demonstrate that concentration-dependent complexation between pollutants significantly alters the toxicity profile of Cu(II)/NC systems. This study highlights the value of voltammetry with a mercury drop working electrode as a reliable method for studying pollutant complexation relevant to ecotoxicity in natural waters.
{"title":"Integrating voltammetry in ecotoxicology: Cu(II)-nitrocatechol complexes formation as a driver of Cu(II) and nitrocatechol toxicity in aquatic systems","authors":"Saranda Bakija Alempijević , Kristijan Vidović , Petra Vukosav , Sanja Frka , Ana Kroflič , Ivan Mihaljević , Irena Grgić , Slađana Strmečki","doi":"10.1016/j.electacta.2025.145938","DOIUrl":"10.1016/j.electacta.2025.145938","url":null,"abstract":"<div><div>Nitrocatechols (NCs) are hazardous environmental pollutants that pose a significant risk to aquatic organisms. The toxicity of pollutants is determined by their speciation, which depends on interactions with coexisting inorganic and organic substances, emphasizing the need for detailed specific studies. Employing square wave and cyclic voltammetry, we investigated the complexation between NCs, specifically 4-nitrocatechol (4NC), 3-methyl-4-nitrocatechol (3M4NC), 3-methyl-5-nitrocatechol (3M5NC), and 4-methyl-5-nitrocatechol (4M5NC), and copper ions (Cu(II)), a micronutrient that is toxic at elevated concentrations. By confirming and following a quasi-reversible two-electron reduction of di-nitrocatecholate [Cu(NC)<sub>2</sub>]<sup>2-</sup> complexes in slightly alkaline solution (pH 8.2), we demonstrated fast complex formation in solution at different analyte concentrations and high kinetic stability. However, the pH lowering resulted in degradation of these complexes, yielding mono-nitrocatecholate [Cu(NC)] species and eventually uncomplexed Cu(II) ions. The chronic toxicity bioassays (AlgaeTox) with <em>Scenedesmus subspicatus</em> microalgae exposed to a mixture of Cu(II) and NCs at different concentrations showed decreased toxicity compared to the toxicity of individual Cu(II) and NCs. This decrease was linked to the formation of [Cu(NC)<sub>2</sub>]<sup>2−</sup> complexes, which was confirmed by the appearance of a corresponding voltammetric reduction peak. Conversely, increased toxicity was observed when the complexes were degraded, resulting in the presence of free/labile Cu(II) or NCs species in the solution. These results demonstrate that concentration-dependent complexation between pollutants significantly alters the toxicity profile of Cu(II)/NC systems. This study highlights the value of voltammetry with a mercury drop working electrode as a reliable method for studying pollutant complexation relevant to ecotoxicity in natural waters.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"522 ","pages":"Article 145938"},"PeriodicalIF":5.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145926
Zhaohua Zeng , Guihua Liu , Tiangui Qi , Qiusheng Zhou , Zhihong Peng , Leiting Shen , Yilin Wang , Xiaobin Li , Yuming Zhang
The directional transformation of pyrite in the concentrated sodium aluminate solution at high temperatures will benefit the sulfur removal and the reduction of red mud, leading to green utilization of bauxite containing sulfur. After calculation of the activity coefficient through the Bromley model, - diagrams of Fe-S-H2O were provided at 298 K and 533 K, respectively. Regulating the potential, caustic alkali concentration, and temperature allowed pyrite to directionally transform into S2O32− and Fe3O4. Increasing caustic alkali concentration enlarged the stable region of S2O32− and Fe3O4, while reducing the stable region of FeS and FeS2. The electrochemical reaction of pyrite depended on the sulfur-bearing anions with different potentials in the sodium aluminate solution. Owing to S2 preferentially adsorbed on the pyrite and readily changing into S0, the thin dense S0 layer enriched on the pyrite surface, inhibiting the reaction of pyrite. S2O32− contributed to the formation of an iron hydroxide layer on the pyrite surface at room temperature, the thick layer of iron hydroxide and iron-deficient sulfide (Fe1-xS2) on pyrite then remarkably restrained the reaction of pyrite. In addition, the negative potential from S2− and S2O32− and high temperatures promoted the formation of magnetite. Inhibiting pyrite reaction, transformation of S2O32−, and formation of magnetite in the digestion of pyrite were all achieved by adding 1 g·L−1 NaNO3, whereas more NaNO3 notably promoted pyrite reaction and formation of hematite at 260 ℃. The mechanism of the directional transformation of pyrite was elucidated, while a green novel process to efficiently utilize bauxite containing sulfur for synchronous desilication and sulfur removal, together with reduction of the red mud through iron recovery was provided. The results provide an insight into electrochemical reaction mechanism of pyrite in Bayer liquor, and novel approach to sulfur removal in desilication and the reduction of red mud after iron recovery.
{"title":"Directional transformation of pyrite in sodium aluminate solution for desulfurization and the reduction of red mud based on electrochemical mechanism","authors":"Zhaohua Zeng , Guihua Liu , Tiangui Qi , Qiusheng Zhou , Zhihong Peng , Leiting Shen , Yilin Wang , Xiaobin Li , Yuming Zhang","doi":"10.1016/j.electacta.2025.145926","DOIUrl":"10.1016/j.electacta.2025.145926","url":null,"abstract":"<div><div>The directional transformation of pyrite in the concentrated sodium aluminate solution at high temperatures will benefit the sulfur removal and the reduction of red mud, leading to green utilization of bauxite containing sulfur. After calculation of the activity coefficient through the Bromley model, <span><math><mi>φ</mi></math></span>-<span><math><mrow><mi>ρ</mi><mo>(</mo><mrow><mi>N</mi><msub><mi>a</mi><mn>2</mn></msub><mi>O</mi></mrow><mo>)</mo></mrow></math></span> diagrams of Fe-S-H<sub>2</sub>O were provided at 298 K and 533 K, respectively. Regulating the potential, caustic alkali concentration, and temperature allowed pyrite to directionally transform into S<sub>2</sub>O<sub>3</sub><sup>2−</sup> and Fe<sub>3</sub>O<sub>4</sub>. Increasing caustic alkali concentration enlarged the stable region of S<sub>2</sub>O<sub>3</sub><sup>2−</sup> and Fe<sub>3</sub>O<sub>4</sub>, while reducing the stable region of FeS and FeS<sub>2</sub>. The electrochemical reaction of pyrite depended on the sulfur-bearing anions with different potentials in the sodium aluminate solution. Owing to S<sup>2</sup> preferentially adsorbed on the pyrite and readily changing into S<sup>0</sup>, the thin dense S<sup>0</sup> layer enriched on the pyrite surface, inhibiting the reaction of pyrite. S<sub>2</sub>O<sub>3</sub><sup>2−</sup> contributed to the formation of an iron hydroxide layer on the pyrite surface at room temperature, the thick layer of iron hydroxide and iron-deficient sulfide (Fe<sub>1-x</sub>S<sub>2</sub>) on pyrite then remarkably restrained the reaction of pyrite. In addition, the negative potential from S<sup>2−</sup> and S<sub>2</sub>O<sub>3</sub><sup>2−</sup> and high temperatures promoted the formation of magnetite. Inhibiting pyrite reaction, transformation of S<sub>2</sub>O<sub>3</sub><sup>2−</sup>, and formation of magnetite in the digestion of pyrite were all achieved by adding 1 g·L<sup>−1</sup> NaNO<sub>3</sub>, whereas more NaNO<sub>3</sub> notably promoted pyrite reaction and formation of hematite at 260 ℃. The mechanism of the directional transformation of pyrite was elucidated, while a green novel process to efficiently utilize bauxite containing sulfur for synchronous desilication and sulfur removal, together with reduction of the red mud through iron recovery was provided. The results provide an insight into electrochemical reaction mechanism of pyrite in Bayer liquor, and novel approach to sulfur removal in desilication and the reduction of red mud after iron recovery.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"522 ","pages":"Article 145926"},"PeriodicalIF":5.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.electacta.2025.145923
N. Anisha, M. Isacfranklin, R. Yuvakkumar, G. Ravi
As a result of the global energy crisis, energy storage plays an important role where supercapacitors play a prominent role in energy storage applications. High-performance supercapacitor electrode materials combining environmental friendliness, high energy density, and exceptional chemical and physical stability are essential for energy storage applications. As electrode morphology significantly affects electrochemical performance, we have chosen metal sulfides to meet such requirements. In this work, we have synthesized NiS2/NiS/rGO with heterostructured morphology by combining nanorods and nanocubes. Material characterization was conducted through XRD, FTIR, and Raman spectroscopy. NiS2/NiS/rGO exhibited a remarkable 1148 F/g at 1 A/g and 1385 F/g for 5 mV/s scan rate. Further investigation into theoretical current and charge contributions was studied using Dunn's and Trasatti's techniques. Two-electrode full-cell fabrication resulted 158 F/g at 0.5A/g, 49 Whkg-1 energy density and 372 Wkg-1 power densities. Stability analysis via GCD at a voltage of 1.5V demonstrated a capacitive retention of 98.2% for the prepared material for 5000 cycles.
{"title":"Synthesis of heterostructured NiS2/NiS/rGO nanocomposite as an effective nanomaterial for supercapacitor application","authors":"N. Anisha, M. Isacfranklin, R. Yuvakkumar, G. Ravi","doi":"10.1016/j.electacta.2025.145923","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145923","url":null,"abstract":"As a result of the global energy crisis, energy storage plays an important role where supercapacitors play a prominent role in energy storage applications. High-performance supercapacitor electrode materials combining environmental friendliness, high energy density, and exceptional chemical and physical stability are essential for energy storage applications. As electrode morphology significantly affects electrochemical performance, we have chosen metal sulfides to meet such requirements. In this work, we have synthesized NiS<sub>2</sub>/NiS/rGO with heterostructured morphology by combining nanorods and nanocubes. Material characterization was conducted through XRD, FTIR, and Raman spectroscopy. NiS<sub>2</sub>/NiS/rGO exhibited a remarkable 1148 F/g at 1 A/g and 1385 F/g for 5 mV/s scan rate. Further investigation into theoretical current and charge contributions was studied using Dunn's and Trasatti's techniques. Two-electrode full-cell fabrication resulted 158 F/g at 0.5A/g, 49 Whkg<sup>-1</sup> energy density and 372 Wkg<sup>-1</sup> power densities. Stability analysis via GCD at a voltage of 1.5V demonstrated a capacitive retention of 98.2% for the prepared material for 5000 cycles.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"23 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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