Pub Date : 2025-01-02DOI: 10.1016/j.electacta.2025.145638
Guanyi Wang, Jie Xiong, Bingyao Zhou, Valliammai Palaniappan, Himanaga Emani, Kevin Mathew, Emmanuel Kornyo, Zachary Tay, Tony Joseph Hanson, Dinesh Maddipatla, Guoxin Zhang, Massood Atashbar, Wenquan Lu, Qingliu Wu
It has been well recognized that introducing secondary porous networks (SPNs) into the electrodes can effectively improve the electrochemical performance of lithium-ion batteries (LIBs), especially under fast-charging operations. However, the process complexity and high cost limit the commercial success of advanced electrodes with SPNs. To address this issue, we developed a facile screen-printing process to produce structured graphite electrodes with SPNs. The experimental results demonstrated that, by tuning the diameter and center-to-center (C2C) distance of emulsion dots on the stencil screen, the pore diameters and C2C pore distances of SPNs in screen-printed electrodes can be precisely controlled in the range of 100 μm to 1mm and 100 μm to 3mm respectively. In addition, the SPNs with hexagonal and square-shape pore alignments have also been imprinted onto the electrode coatings through adjusting the patterns of screen stencils. Used as anodes, the printed graphite electrodes demonstrated significantly reduced overpotential and voltage fluctuation under fast-charging operations from 2C to 6C. Coupled with LiNi0.6Mn0.2Co0.2O2 (NMC622) cathodes, the full cells with printed graphite anodes exhibited an unprecedently stable performance with almost no capacity decay up to 170 cycles when charged to 80% SOC at 2C. Observations from electron microscopy showed plated lithium undetectable at the surface of printed graphite electrodes after numerous cycles. The electrochemical analysis on the voltage evolution during the cell rest period indicated the significantly delayed onset of lithium plating in the presence of printed graphite electrodes. All these results suggest that the significantly improved cell performance is associated with the shortened Li-ion diffusion distance, reduced polarization and suppressed Li plating in the printed electrodes with patterned SPNs.
{"title":"Enabling Fast-Charging of Lithium-Ion Batteries through Printed Electrodes","authors":"Guanyi Wang, Jie Xiong, Bingyao Zhou, Valliammai Palaniappan, Himanaga Emani, Kevin Mathew, Emmanuel Kornyo, Zachary Tay, Tony Joseph Hanson, Dinesh Maddipatla, Guoxin Zhang, Massood Atashbar, Wenquan Lu, Qingliu Wu","doi":"10.1016/j.electacta.2025.145638","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.145638","url":null,"abstract":"It has been well recognized that introducing secondary porous networks (SPNs) into the electrodes can effectively improve the electrochemical performance of lithium-ion batteries (LIBs), especially under fast-charging operations. However, the process complexity and high cost limit the commercial success of advanced electrodes with SPNs. To address this issue, we developed a facile screen-printing process to produce structured graphite electrodes with SPNs. The experimental results demonstrated that, by tuning the diameter and center-to-center (C2C) distance of emulsion dots on the stencil screen, the pore diameters and C2C pore distances of SPNs in screen-printed electrodes can be precisely controlled in the range of 100 μm to 1mm and 100 μm to 3mm respectively. In addition, the SPNs with hexagonal and square-shape pore alignments have also been imprinted onto the electrode coatings through adjusting the patterns of screen stencils. Used as anodes, the printed graphite electrodes demonstrated significantly reduced overpotential and voltage fluctuation under fast-charging operations from 2C to 6C. Coupled with LiNi<sub>0.6</sub>Mn<sub>0.2</sub>Co<sub>0.2</sub>O<sub>2</sub> (NMC622) cathodes, the full cells with printed graphite anodes exhibited an unprecedently stable performance with almost no capacity decay up to 170 cycles when charged to 80% SOC at 2C. Observations from electron microscopy showed plated lithium undetectable at the surface of printed graphite electrodes after numerous cycles. The electrochemical analysis on the voltage evolution during the cell rest period indicated the significantly delayed onset of lithium plating in the presence of printed graphite electrodes. All these results suggest that the significantly improved cell performance is associated with the shortened Li-ion diffusion distance, reduced polarization and suppressed Li plating in the printed electrodes with patterned SPNs.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"25 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912043","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145630
Asridin Dayan, Kobra Azizi, Lars Nilausen Cleemann, Dirk Henkensmeier
According to literature, the reduced hydrophilicity of phosphoric acid (PA) doped PBI membranes in comparison to PA itself is advantageous in high temperature polymer electrolyte fuel cells (HT PEMFCs) fed with dry gases, because the presence of H3O+ results in electro-osmotic drag and thus drying of the anode side. For HT PEMFC operated with water containing reformate, this should be less of an issue, and membranes with increased water contents are expected to have higher conductivity without being affected by anode drying. Therefore, this work investigates the properties and performance of a sulfonated para-PBI membrane, crosslinked with 5 wt% dibromoxylene (5MS-PBI), for use in reformate-fueled HT PEMFC. We show that the concentration of the absorbed acid is 82 wt% for 5MS-PBI but 90 wt% for commercial standard meta-PBI. Even though 5MS-PBI absorbs only half of the PA than meta-PBI, it shows an improved conductivity, and in the HT PEMFC operating with reformate (6.9% H2O, 1.4% CO, 22.3 % CO2, 69.3 % H2), the power densities at 700 mA cm−2 and 170°C, 1 bar backpressure were 434 with meta-PBI and 454 mW cm−2 with 5MS-PBI. At 160°C, without backpressure, power densities were 364 and 401 mW cm−2, respectively.
{"title":"Dibromoxylene-crosslinked sulfonated para-PBI membranes for use in high temperature polymer electrolyte membrane fuel cells operating with reformate gas","authors":"Asridin Dayan, Kobra Azizi, Lars Nilausen Cleemann, Dirk Henkensmeier","doi":"10.1016/j.electacta.2024.145630","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145630","url":null,"abstract":"According to literature, the reduced hydrophilicity of phosphoric acid (PA) doped PBI membranes in comparison to PA itself is advantageous in high temperature polymer electrolyte fuel cells (HT PEMFCs) fed with dry gases, because the presence of H<sub>3</sub>O<sup>+</sup> results in electro-osmotic drag and thus drying of the anode side. For HT PEMFC operated with water containing reformate, this should be less of an issue, and membranes with increased water contents are expected to have higher conductivity without being affected by anode drying. Therefore, this work investigates the properties and performance of a sulfonated <em>para</em>-PBI membrane, crosslinked with 5 wt% dibromoxylene (5MS-PBI), for use in reformate-fueled HT PEMFC. We show that the concentration of the absorbed acid is 82 wt% for 5MS-PBI but 90 wt% for commercial standard <em>meta</em>-PBI. Even though 5MS-PBI absorbs only half of the PA than <em>meta</em>-PBI, it shows an improved conductivity, and in the HT PEMFC operating with reformate (6.9% H<sub>2</sub>O, 1.4% CO, 22.3 % CO<sub>2</sub>, 69.3 % H<sub>2</sub>), the power densities at 700 mA cm<sup>−2</sup> and 170°C, 1 bar backpressure were 434 with <em>meta</em>-PBI and 454 mW cm<sup>−2</sup> with 5MS-PBI. At 160°C, without backpressure, power densities were 364 and 401 mW cm<sup>−2</sup>, respectively.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"114 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908536","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145632
Md Habibur Rahman, Irwin C. Loud IV, Vu Q. Do, Md Abdul Hamid, Kyle C. Smith
Interdigitated flow fields (IDFFs) stand out among flow fields used in electrochemical energy storage and conversion for their modest pressure drop through electrodes. While recent efforts have sought to optimize flow-field topologies and channel shapes, we present a bottom-up strategy to taper channel cross-sections in IDFFs to maximize flow uniformity, eliminating the dead zones that plague straight channels. A linear variation in channel hydraulic conductance is shown to produce constant inter-channel velocity with minimal pressure drop, and mapping between conductance and cross-section geometry with appropriate Poiseuille flow relations enables their implementation. Using a micro-engraving process, we design and manufacture tapered channels having piecewise-constant cross-sections chosen from a library with different nominal widths and depths. The spacing between channels is then optimized to simultaneously minimize material removal and maximize apparent hydraulic permeability. Such tapered-channel IDFFs are embedded in porous, cation-intercalating electrodes for use in desalination by symmetric Faradaic deionization (FDI), where an increase in hydraulic permeability of tapered channels greater than two-fold compared to straight channels is shown to reduce pumping energy by 62% when desalinating seawater-salinity feeds. Energy efficiency doubles at 50% salt removal as a result, motivating hybridization of FDI with conventional desalination processes. Total energy consumption levels of 7.3 kWh/m³ and 0.69 kWh/m³ to produce freshwater respectively from seawater-salinity and brackish feeds is lower than small-scale reverse osmosis and thermal distillation. Low-pressure, high-efficiency operation enabled by IDFFs designed with optimally tapered channels motivates their broad use in flow-based electrochemical separations, energy storage, and energy conversion.
{"title":"Tapered, Interdigitated Channels for Uniform, Low-Pressure Flow through Porous Electrodes for Desalination and Beyond","authors":"Md Habibur Rahman, Irwin C. Loud IV, Vu Q. Do, Md Abdul Hamid, Kyle C. Smith","doi":"10.1016/j.electacta.2024.145632","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145632","url":null,"abstract":"Interdigitated flow fields (IDFFs) stand out among flow fields used in electrochemical energy storage and conversion for their modest pressure drop through electrodes. While recent efforts have sought to optimize flow-field topologies and channel shapes, we present a bottom-up strategy to taper channel cross-sections in IDFFs to maximize flow uniformity, eliminating the dead zones that plague straight channels. A linear variation in channel hydraulic conductance is shown to produce constant inter-channel velocity with minimal pressure drop, and mapping between conductance and cross-section geometry with appropriate Poiseuille flow relations enables their implementation. Using a micro-engraving process, we design and manufacture tapered channels having piecewise-constant cross-sections chosen from a library with different nominal widths and depths. The spacing between channels is then optimized to simultaneously minimize material removal and maximize apparent hydraulic permeability. Such tapered-channel IDFFs are embedded in porous, cation-intercalating electrodes for use in desalination by symmetric Faradaic deionization (FDI), where an increase in hydraulic permeability of tapered channels greater than two-fold compared to straight channels is shown to reduce pumping energy by 62% when desalinating seawater-salinity feeds. Energy efficiency doubles at 50% salt removal as a result, motivating hybridization of FDI with conventional desalination processes. Total energy consumption levels of 7.3 kWh/m³ and 0.69 kWh/m³ to produce freshwater respectively from seawater-salinity and brackish feeds is lower than small-scale reverse osmosis and thermal distillation. Low-pressure, high-efficiency operation enabled by IDFFs designed with optimally tapered channels motivates their broad use in flow-based electrochemical separations, energy storage, and energy conversion.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"13 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908540","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145603
Dhruv Chauhan, Rahul Gupta, Nishith Verma
Riboflavin (RF) is detected via an in situ spectroelectrochemistry (SEC) technique using the laser induced graphene (LIG)-anchored iron nanoparticles (Fe NPs) modified fluorine tin oxide (FTO) glass electrode. The Fe-dispersed phenol-formaldehyde copolymeric film is converted to Fe-LIG in a single step via laser ablation. Synchronously coupled with cyclic voltammetry, the UV-Vis spectrophotometry is used to measure the electro-reduced RF species, based on the absorbance peak at ∼400 nm wavelength. The Fe-LIG modification of FTO increases the electrochemical surface area of the electrode approximately 3 times, leading to a greater sensitivity and diminished charge transfer resistance necessary for the electrochemical reduction of RF. A linear response of the sensor is observed for the RF concentration ranging from 0.05 - 40 µg/ml, with a low limit of detection of 0.048 µg/ml. The sensor was successfully tested in artificial urine to replicate the real sample analysis. The SEC sensor was also tested in the interferent-laden RF solutions where the unaltered peak intensities in the absorbance spectra were observed, clearly justifying the use of SEC in lieu of the electrochemical or UV-Vis spectrophotometry techniques alone where the convolution, disfigurement, or alteration in peak intensity of the interferents is commonly observed. The findings in this study have paved way for the application of an inexpensive metal-LIG composite-based electrode in conjunction with the SEC approach for the interference-free sensing of critical biomolecules.
{"title":"Selective detection of riboflavin biomolecule via electroreduction over laser induced graphene-anchored iron nanoparticles using spectroelectrochemistry","authors":"Dhruv Chauhan, Rahul Gupta, Nishith Verma","doi":"10.1016/j.electacta.2024.145603","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145603","url":null,"abstract":"Riboflavin (RF) is detected via an <em>in situ</em> spectroelectrochemistry (SEC) technique using the laser induced graphene (LIG)-anchored iron nanoparticles (Fe NPs) modified fluorine tin oxide (FTO) glass electrode. The Fe-dispersed phenol-formaldehyde copolymeric film is converted to Fe-LIG in a single step via laser ablation. Synchronously coupled with cyclic voltammetry, the UV-Vis spectrophotometry is used to measure the electro-reduced RF species, based on the absorbance peak at ∼400 nm wavelength. The Fe-LIG modification of FTO increases the electrochemical surface area of the electrode approximately 3 times, leading to a greater sensitivity and diminished charge transfer resistance necessary for the electrochemical reduction of RF. A linear response of the sensor is observed for the RF concentration ranging from 0.05 - 40 µg/ml, with a low limit of detection of 0.048 µg/ml. The sensor was successfully tested in artificial urine to replicate the real sample analysis. The SEC sensor was also tested in the interferent-laden RF solutions where the unaltered peak intensities in the absorbance spectra were observed, clearly justifying the use of SEC in lieu of the electrochemical or UV-Vis spectrophotometry techniques alone where the convolution, disfigurement, or alteration in peak intensity of the interferents is commonly observed. The findings in this study have paved way for the application of an inexpensive metal-LIG composite-based electrode in conjunction with the SEC approach for the interference-free sensing of critical biomolecules.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"3 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908542","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145635
Luiz Ricardo G. Silva, Raquel G. Rocha, Diego P. Rocha, Edson Nossol, Bruno C. Janegitz, Eduardo M. Ritcher, Rodrigo A.A. Munoz, Jessica S. Stefano
The 3D printing technology has the ability to manufacture electrochemical sensors in complex three-dimensional shapes with high efficiency and precision. In parallel, laser scribing technology has been employed to manufacture low-cost and disposable electrochemical sensors. Hence, the combination of both technologies can bring numerous possibilities in the field of electrochemical sensors. The present work addresses the possibility of modifying the surface of 3D printed electrodes through a highly sustainable, practical, and inexpensive route using laser irradiation. For this, a surface modification of a carbon black-based 3D printed electrode was performed using a cobalt chloride solution dropped onto the electrode surface, followed by blue laser irradiation. With this, it was possible to provide an improved electrochemical sensor modified in situ with cobalt oxides, as further attested by physicochemical and electrochemical characterizations. The modified sensor was employed for glucose (GLU) determination using a Batch Injection Analysis (BIA) system. From the modification, the cobalt oxides upon the electrode surface allowed the sensitive detection of GLU in a linear range from 50.0 to 400.0 µmol L−1 and LOD of 6.3 µmol L−1. The GLU analysis in the biological samples yielded recovery values close to 100%, demonstrating good applicability of the sensor. Thus, the combination of 3D printing and laser scribing technology enabled the production of modified sensors that are highly robust and capable of performing the selective detection of GLU in an easy and simple way.
{"title":"Laser-induced cobalt oxide entrapment within 3D-printed carbon electrodes for amperometric sensing","authors":"Luiz Ricardo G. Silva, Raquel G. Rocha, Diego P. Rocha, Edson Nossol, Bruno C. Janegitz, Eduardo M. Ritcher, Rodrigo A.A. Munoz, Jessica S. Stefano","doi":"10.1016/j.electacta.2024.145635","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145635","url":null,"abstract":"The 3D printing technology has the ability to manufacture electrochemical sensors in complex three-dimensional shapes with high efficiency and precision. In parallel, laser scribing technology has been employed to manufacture low-cost and disposable electrochemical sensors. Hence, the combination of both technologies can bring numerous possibilities in the field of electrochemical sensors. The present work addresses the possibility of modifying the surface of 3D printed electrodes through a highly sustainable, practical, and inexpensive route using laser irradiation. For this, a surface modification of a carbon black-based 3D printed electrode was performed using a cobalt chloride solution dropped onto the electrode surface, followed by blue laser irradiation. With this, it was possible to provide an improved electrochemical sensor modified in situ with cobalt oxides, as further attested by physicochemical and electrochemical characterizations. The modified sensor was employed for glucose (GLU) determination using a Batch Injection Analysis (BIA) system. From the modification, the cobalt oxides upon the electrode surface allowed the sensitive detection of GLU in a linear range from 50.0 to 400.0 µmol L<sup>−1</sup> and LOD of 6.3 µmol L<sup>−1</sup>. The GLU analysis in the biological samples yielded recovery values close to 100%, demonstrating good applicability of the sensor. Thus, the combination of 3D printing and laser scribing technology enabled the production of modified sensors that are highly robust and capable of performing the selective detection of GLU in an easy and simple way.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"23 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908537","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145618
M. Varun Karthik, Sruthy Subash, K. Kamala Bharathi
Research and development in Li-ion micro-batteries are focusing on improving their performance, energy density, and cost-effectiveness. These batteries continue to be an area of interest for applications where traditional battery technologies may not be as suitable due to size and weight constraints. In the present work, we report on the electrochemical properties, Li-ion dynamics, various contributions to charge storage, and the ability to glow a light-emitting diode (LED) using Li-Nb-O thin film electrodes deposited via the RF magnetron sputtering technique. X-ray diffraction and Raman spectra analysis identified mixed phases of the thin film of tetragonal Nb₂O₅ and monoclinic LiNb₃O₈, both phases displaying the Nb⁵⁺ oxidation state, as verified by X-ray photoelectron spectroscopy. The cyclic voltammogram and dQ/dV plots demonstrated the two-electron transfers from each phase of the film and the kinetic property of the mixed phase is significantly contributed by both intercalation and pseudocapacitance behavior. The Li-Nb-O ultra-thin film of 19 nm delivers an initial discharge capacity of 9.9 µAh/cm² at a current density of 20 µA/cm² and attained capacity retention of 75.75% after 300 cycles, indicating improved lithium storage. Additionally, impedance measurements are conducted to assess the reduction in charge transfer resistance before and after cycling, and to determine the Li-ion diffusion coefficient, which ranged from 10⁻¹⁷ to 10⁻²⁰ cm²/s in the thin film. Thus, the Li-Nb-O thin films can be suitable as a negative electrode in all-solid thin film micro-batteries applications.
{"title":"High-Rate Performance of Ultra-Thin Li-Nb-O Thin Films as an Anode for Li-ion Micro-Battery Applications","authors":"M. Varun Karthik, Sruthy Subash, K. Kamala Bharathi","doi":"10.1016/j.electacta.2024.145618","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145618","url":null,"abstract":"Research and development in Li-ion micro-batteries are focusing on improving their performance, energy density, and cost-effectiveness. These batteries continue to be an area of interest for applications where traditional battery technologies may not be as suitable due to size and weight constraints. In the present work, we report on the electrochemical properties, Li-ion dynamics, various contributions to charge storage, and the ability to glow a light-emitting diode (LED) using Li-Nb-O thin film electrodes deposited via the RF magnetron sputtering technique. X-ray diffraction and Raman spectra analysis identified mixed phases of the thin film of tetragonal Nb₂O₅ and monoclinic LiNb₃O₈, both phases displaying the Nb⁵⁺ oxidation state, as verified by X-ray photoelectron spectroscopy. The cyclic voltammogram and dQ/dV plots demonstrated the two-electron transfers from each phase of the film and the kinetic property of the mixed phase is significantly contributed by both intercalation and pseudocapacitance behavior. The Li-Nb-O ultra-thin film of 19 nm delivers an initial discharge capacity of 9.9 µAh/cm² at a current density of 20 µA/cm² and attained capacity retention of 75.75% after 300 cycles, indicating improved lithium storage. Additionally, impedance measurements are conducted to assess the reduction in charge transfer resistance before and after cycling, and to determine the Li-ion diffusion coefficient, which ranged from 10⁻¹⁷ to 10⁻²⁰ cm²/s in the thin film. Thus, the Li-Nb-O thin films can be suitable as a negative electrode in all-solid thin film micro-batteries applications.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912037","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145633
Jeanet Conradie
This work presents a critical review of the electrochemistry of osmium(II)-polypyridines, supported by Density Functional Theory (DFT) studies, focusing on phenanthroline, bipyridine, terpyridine, and their substituted derivatives. The results demonstrate that osmium(II)-bipyridines, osmium(II)-phenanthrolines, and osmium(II)-terpyridines exhibit similar redox behavior. The reversible one-electron oxidation of these d6 osmium(II)-polypyridines leads to the formation of d5 osmium(III)-polypyridines, which maintain a similar molecular structure. The one-electron reduction of these osmium(II)-polypyridines produces a reduced molecule with a d6 osmium(II) center, accompanied by one ligand radical (containing one unpaired electron) and one neutral ligand (for terpyridine) or two neutral ligands (for phenanthroline or bipyridine). The electronic structures of DFT-optimized osmium(III)-polypyridines, osmium(II)-polypyridines, and their reduced forms support the experimental assignment of the observed redox processes. Additionally, the oxidation potentials of osmium(II)-polypyridines are determined to be directly related to the highest occupied molecular orbital (HOMO) energies of the DFT-optimized osmium(II)-polypyridines making it possible to predict redox potentials of related systems. In conclusion, the limitations of the published work are critically assessed, and potential future perspectives are thoughtfully explored.
{"title":"A Review of Electrochemistry of osmium(II)-polypyridines and supporting DFT studies","authors":"Jeanet Conradie","doi":"10.1016/j.electacta.2024.145633","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145633","url":null,"abstract":"This work presents a critical review of the electrochemistry of osmium(II)-polypyridines, supported by Density Functional Theory (DFT) studies, focusing on phenanthroline, bipyridine, terpyridine, and their substituted derivatives. The results demonstrate that osmium(II)-bipyridines, osmium(II)-phenanthrolines, and osmium(II)-terpyridines exhibit similar redox behavior. The reversible one-electron oxidation of these d<sup>6</sup> osmium(II)-polypyridines leads to the formation of d<sup>5</sup> osmium(III)-polypyridines, which maintain a similar molecular structure. The one-electron reduction of these osmium(II)-polypyridines produces a reduced molecule with a d<sup>6</sup> osmium(II) center, accompanied by one ligand radical (containing one unpaired electron) and one neutral ligand (for terpyridine) or two neutral ligands (for phenanthroline or bipyridine). The electronic structures of DFT-optimized osmium(III)-polypyridines, osmium(II)-polypyridines, and their reduced forms support the experimental assignment of the observed redox processes. Additionally, the oxidation potentials of osmium(II)-polypyridines are determined to be directly related to the highest occupied molecular orbital (HOMO) energies of the DFT-optimized osmium(II)-polypyridines making it possible to predict redox potentials of related systems. In conclusion, the limitations of the published work are critically assessed, and potential future perspectives are thoughtfully explored.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"6 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908535","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}
The ion current rectification (ICR) phenomenon is well known due to the diode-like response behavior that attracts increasing research interest. However, most studies focus on the single channel with fixed surface charge, and the dependent ion transport behavior in highly coupled solution-surface-membrane has not been fully studied so far. Herein, a coupled ion transport model in the SiO2/Al2O3 membrane channel is proposed to investigate the asymmetric response behavior. The results show that SiO2 and Al2O3 membrane enable the negative and positive surface charge that forms a heterojunction channel. This leads to significant ion rectification due to the asymmetrical surface charge property. Besides, the surface property of the membrane is highly regulated by solution pH and the acidic environment is more conducive to the enhancement of asymmetric ion transport. Further study shows that the best heterojunction ratio is 1:1 of the lengths of negative charge regions to that of positive charge regions. The research results provide valuable information on ion transport and nanofluidic devices.
{"title":"pH-regulated Electrokinetic Ion Rectification in SiO2/Al2O3 Heterojunction Membrane Channel","authors":"Dafeng Yang, Zheng Liu, Nan Qiao, Changzheng Li, Zhongbao Liu, Zhipeng Qie","doi":"10.1016/j.electacta.2024.145634","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145634","url":null,"abstract":"The ion current rectification (ICR) phenomenon is well known due to the diode-like response behavior that attracts increasing research interest. However, most studies focus on the single channel with fixed surface charge, and the dependent ion transport behavior in highly coupled solution-surface-membrane has not been fully studied so far. Herein, a coupled ion transport model in the SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> membrane channel is proposed to investigate the asymmetric response behavior. The results show that SiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub> membrane enable the negative and positive surface charge that forms a heterojunction channel. This leads to significant ion rectification due to the asymmetrical surface charge property. Besides, the surface property of the membrane is highly regulated by solution pH and the acidic environment is more conducive to the enhancement of asymmetric ion transport. Further study shows that the best heterojunction ratio is 1:1 of the lengths of negative charge regions to that of positive charge regions. The research results provide valuable information on ion transport and nanofluidic devices.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"34 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908539","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145631
Beatriz A. Riga-Rocha, Valdecir A. Paganin, Massimiliano Lo Faro, Sebastian Vecino-Mantilla, Zahreddine Hafsi, Fabiana Matos de Oliveira, Edson A. Ticianelli, Joelma Perez
The reduction of operating temperatures of solid oxide electrochemical cells requires the development of novel materials, particularly those with high conductive charge carriers. This scenario presents challenges in developing proton conductive electrolytes and optimizing thermal treatments for their densification. A simple strategy for obtaining dense BaZr0.8Y0.2O3-δ (BZY) and BaZr0.7Ce0.2Y0.1O3-δ (BZCY) ceramics, which represent the most frequently investigated proton conductive ceramics today, is presented in this paper and complies with using a low percentage of nickel or copper (1 wt.%), while minimizing their inclusion in the structure in order to minimize their possible electronic leakage in the electrolyte. Structural, morphological, and electrochemical analyses were carried out and results demonstrated a dependence of the overall conductivity on the type of perovskite and the nature of sintering aid, as well as the structural and morphological characteristics of BZY and BZCY. There is a noticeable difference between BZY and BZCY in terms of the propensity to achieve high densification, with the second more prone to do this. On the other hand, BZCY showed a particular tendency to pomote electronic leakages, particularly at high temperatures due to the presence of Ce and exacerbated by reducing conditions. In spite of the 99.2% densification achieved with Cu-doped BZCY prepared according to one of the empolyed methods, the morphology must be improved further for the specimen to gain superior electrical properties.
{"title":"Insights on the electrochemical behavior of BZY and BZCY proton conductors densified with a low percentage of Ni or Cu","authors":"Beatriz A. Riga-Rocha, Valdecir A. Paganin, Massimiliano Lo Faro, Sebastian Vecino-Mantilla, Zahreddine Hafsi, Fabiana Matos de Oliveira, Edson A. Ticianelli, Joelma Perez","doi":"10.1016/j.electacta.2024.145631","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145631","url":null,"abstract":"The reduction of operating temperatures of solid oxide electrochemical cells requires the development of novel materials, particularly those with high conductive charge carriers. This scenario presents challenges in developing proton conductive electrolytes and optimizing thermal treatments for their densification. A simple strategy for obtaining dense BaZr<sub>0.8</sub>Y<sub>0.2</sub>O<sub>3-δ</sub> (BZY) and BaZr<sub>0.7</sub>Ce<sub>0.2</sub>Y<sub>0.1</sub>O<sub>3-δ</sub> (BZCY) ceramics, which represent the most frequently investigated proton conductive ceramics today, is presented in this paper and complies with using a low percentage of nickel or copper (1 wt.%), while minimizing their inclusion in the structure in order to minimize their possible electronic leakage in the electrolyte. Structural, morphological, and electrochemical analyses were carried out and results demonstrated a dependence of the overall conductivity on the type of perovskite and the nature of sintering aid, as well as the structural and morphological characteristics of BZY and BZCY. There is a noticeable difference between BZY and BZCY in terms of the propensity to achieve high densification, with the second more prone to do this. On the other hand, BZCY showed a particular tendency to pomote electronic leakages, particularly at high temperatures due to the presence of Ce and exacerbated by reducing conditions. In spite of the 99.2% densification achieved with Cu-doped BZCY prepared according to one of the empolyed methods, the morphology must be improved further for the specimen to gain superior electrical properties.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"93 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908538","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 : 2025-01-01DOI: 10.1016/j.electacta.2024.145582
S. Arun Kumar, I. Sarasamreen, A. Vinnarasi, A. Gowdhaman, C. Balaji, S. Prabhu, R. Ramesh, P.M. Anbarasan
Supercapacitors and batteries, two extremely capable and competent energy storage technologies, were able to satisfactorily supply the energy requirement in industrial-scale electronic equipment. In this approach, developing unique and morphology-dependable electrodes with good capacity performance plays a moral role in energy storage technologies. In this present work, nickel oxide (NiO) microflowers were hydrothermally bestowed on the Ni-foam current collector via binder-free process in energy storage applications. The NiO/NF cathode material delivered an admirable capacitance (capacity) of ∼ 1381.8 F g-1 (∼ 212.49 mA h g-1) under the current density of 2 A g-1 with better stability retention of 84.59 % over 5000 cycles. By coupling with a BiVO4/NF anode, the assembled NiO||BiVO4 supercapattery device achieved peak energy and power densities of ∼ 38 Wh kg-1 and ∼ 9600 W kg-1, respectively. A researchable full-cell Ni-Zn battery was employed with NiO/NF as a cathode and a Zn plate as anode, which were assessed in an aqueous electrolyte medium. As a result, the aqueous Ni-Zn cell reached peak energy and power densities of ∼ 157.14 Wh kg-1 and ∼ 13.4 k W kg-1 along with 86 % of cycling retention after 5000 cycles. The arisen capacity and exceptional stability performance of the device may provide sufficient NiO electroactive sites during the Zn+ ions insertion/desertion process. This electrochemical investigation provides good redox performance, further, we conclude that NiO/NF microflower cathode material is as promised as an electrochemical energy storage system.
{"title":"Achieving superior performance in aqueous supercapatteries and Ni-Zn batteries by employing 3D-NiO flowers/NF electrode","authors":"S. Arun Kumar, I. Sarasamreen, A. Vinnarasi, A. Gowdhaman, C. Balaji, S. Prabhu, R. Ramesh, P.M. Anbarasan","doi":"10.1016/j.electacta.2024.145582","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145582","url":null,"abstract":"Supercapacitors and batteries, two extremely capable and competent energy storage technologies, were able to satisfactorily supply the energy requirement in industrial-scale electronic equipment. In this approach, developing unique and morphology-dependable electrodes with good capacity performance plays a moral role in energy storage technologies. In this present work, nickel oxide (NiO) microflowers were hydrothermally bestowed on the Ni-foam current collector via binder-free process in energy storage applications. The NiO/NF cathode material delivered an admirable capacitance (capacity) of ∼ 1381.8 F g<sup>-1</sup> (∼ 212.49 mA h g<sup>-1</sup>) under the current density of 2 A g<sup>-1</sup> with better stability retention of 84.59 % over 5000 cycles. By coupling with a BiVO<sub>4</sub>/NF anode, the assembled NiO||BiVO<sub>4</sub> supercapattery device achieved peak energy and power densities of ∼ 38 Wh kg<sup>-1</sup> and ∼ 9600 W kg<sup>-1</sup>, respectively. A researchable full-cell Ni-Zn battery was employed with NiO/NF as a cathode and a Zn plate as anode, which were assessed in an aqueous electrolyte medium. As a result, the aqueous Ni-Zn cell reached peak energy and power densities of ∼ 157.14 Wh kg<sup>-1</sup> and ∼ 13.4 k W kg<sup>-1</sup> along with 86 % of cycling retention after 5000 cycles. The arisen capacity and exceptional stability performance of the device may provide sufficient NiO electroactive sites during the Zn<sup>+</sup> ions insertion/desertion process. This electrochemical investigation provides good redox performance, further, we conclude that NiO/NF microflower cathode material is as promised as an electrochemical energy storage system.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908469","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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