Pub Date : 2026-10-14DOI: 10.1016/j.electacta.2026.150197
Haoyu Zhai, Chenghao Man, Qian Rong, Ting Zhu
Conventional supercapacitors are limited by incomplete active-site utilization and sluggish interfacial charge transfer. Photo-assisted energy storage offers a route to regulate these processes using photogenerated carriers. In this work, a self-supported CC@ZIF-67/Ni/P electrode was prepared by in situ growth of ZIF-67 on carbon cloth, followed by Ni incorporation and phosphorus-source regulation. The central design feature is a Ni-P/NiOOH heterointerface formed within an open porous nanosheet network. HRTEM and XPS provide local structural and surface-chemical evidence for this composite interface. The porous network improves electrolyte accessibility, and defect-related states may assist carrier trapping and migration; however, heterointerfacial coupling is proposed to play the principal role and may facilitate interfacial electron transfer and photogenerated-carrier separation. Under illumination, the electrode reaches an areal capacitance of 1868 mF·cm−2 at 10 mA·cm−2, together with a lower apparent interfacial resistance and a reproducible light-on/light-off transient response. The illuminated electrode retains 16.9% of its initial capacitance after 10,000 cycles, identifying long-term durability as a remaining limitation. These results support further investigation of interfacial coupling in MOF-derived photo-assisted electrodes.
{"title":"Ni-P/NiOOH Heterointerface and Defect-Regulated ZIF-67-Derived Porous Nanosheet Electrodes for Photo-Assisted Supercapacitive Energy Storage","authors":"Haoyu Zhai, Chenghao Man, Qian Rong, Ting Zhu","doi":"10.1016/j.electacta.2026.150197","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150197","url":null,"abstract":"Conventional supercapacitors are limited by incomplete active-site utilization and sluggish interfacial charge transfer. Photo-assisted energy storage offers a route to regulate these processes using photogenerated carriers. In this work, a self-supported CC@ZIF-67/Ni/P electrode was prepared by in situ growth of ZIF-67 on carbon cloth, followed by Ni incorporation and phosphorus-source regulation. The central design feature is a Ni-P/NiOOH heterointerface formed within an open porous nanosheet network. HRTEM and XPS provide local structural and surface-chemical evidence for this composite interface. The porous network improves electrolyte accessibility, and defect-related states may assist carrier trapping and migration; however, heterointerfacial coupling is proposed to play the principal role and may facilitate interfacial electron transfer and photogenerated-carrier separation. Under illumination, the electrode reaches an areal capacitance of 1868 mF·cm<ce:sup loc=\"post\">−2</ce:sup> at 10 mA·cm<ce:sup loc=\"post\">−2</ce:sup>, together with a lower apparent interfacial resistance and a reproducible light-on/light-off transient response. The illuminated electrode retains 16.9% of its initial capacitance after 10,000 cycles, identifying long-term durability as a remaining limitation. These results support further investigation of interfacial coupling in MOF-derived photo-assisted electrodes.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"73 1","pages":"150197"},"PeriodicalIF":6.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221592","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}
Accurate and rapid detection of oxytetracycline (OTC) in real samples, which is one of the most used and typical tetracycline antibiotics, is of crucial importance for protecting ecological health and supporting effective environmental monitoring. However, achieving free-interference and detection of OTC is a formidable challenge. Herein, a high-performance and low potential electrochemical sensor (Mo2C/GCE) based on hollow molybdenum carbide (Mo2C)/carbon spheres modified glassy carbon electrode (GCE) is reported to achieve free-interference, accurate for detection of OTC. The hollow Mo2C/carbon spheres not only exhibited enzyme like activity, along with a significantly higher specific surface area and a greater density of accessible active sites compared to conventional two-dimensional carbon-based materials. In addition, Mo2C was subjected to high potential oxidation during electrocatalysis, resulting in the formation of numerous surface defects and carbonyl functional groups on its carbon material surface. These defects and carboxyl groups provide more electrochemical active sites and reduce the oxidation overpotential of OTC, facilitating the interface electron transfer. Thus, the electrochemical oxidation potential of OTC on Mo2C/GCE decreased from 0.78 V to 0.64 V compared with the GCE. Mo2C/GCE for the detection of OTC using amperometry analysis exhibited a wide linear range of 0.01∼2000 μM as well as a low limit of detection (LOD) of 0.01 μM. Ultimately, the developed sensor was demonstrated for measurement of OTC in tap water and milk at low potential. Considering the excellent analytical performance and of the prepared electrochemical sensor, its potential for detection of OTC in environmental monitoring and public health, is demonstrated.
{"title":"Low-potential Electrochemical Sensor based on Hollow Molybdenum Carbide/Carbon Spheres for Detection of Oxytetracycline in Tap Water and Milk","authors":"Liyun Shi, Dongyang Wang, Ziyang Wang, Wenwen Wu, Caixia Zhu, Wei Shen, Hian Kee Lee, Sheng Tang","doi":"10.1016/j.electacta.2026.150211","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150211","url":null,"abstract":"Accurate and rapid detection of oxytetracycline (OTC) in real samples, which is one of the most used and typical tetracycline antibiotics, is of crucial importance for protecting ecological health and supporting effective environmental monitoring. However, achieving free-interference and detection of OTC is a formidable challenge. Herein, a high-performance and low potential electrochemical sensor (Mo<ce:inf loc=\"post\">2</ce:inf>C/GCE) based on hollow molybdenum carbide (Mo<ce:inf loc=\"post\">2</ce:inf>C)/carbon spheres modified glassy carbon electrode (GCE) is reported to achieve free-interference, accurate for detection of OTC. The hollow Mo<ce:inf loc=\"post\">2</ce:inf>C/carbon spheres not only exhibited enzyme like activity, along with a significantly higher specific surface area and a greater density of accessible active sites compared to conventional two-dimensional carbon-based materials. In addition, Mo<ce:inf loc=\"post\">2</ce:inf>C was subjected to high potential oxidation during electrocatalysis, resulting in the formation of numerous surface defects and carbonyl functional groups on its carbon material surface. These defects and carboxyl groups provide more electrochemical active sites and reduce the oxidation overpotential of OTC, facilitating the interface electron transfer. Thus, the electrochemical oxidation potential of OTC on Mo<ce:inf loc=\"post\">2</ce:inf>C/GCE decreased from 0.78 V to 0.64 V compared with the GCE. Mo<ce:inf loc=\"post\">2</ce:inf>C/GCE for the detection of OTC using amperometry analysis exhibited a wide linear range of 0.01∼2000 μM as well as a low limit of detection (LOD) of 0.01 μM. Ultimately, the developed sensor was demonstrated for measurement of OTC in tap water and milk at low potential. Considering the excellent analytical performance and of the prepared electrochemical sensor, its potential for detection of OTC in environmental monitoring and public health, is demonstrated.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"22 1","pages":"150211"},"PeriodicalIF":6.6,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221612","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 : 2026-10-14DOI: 10.1016/j.electacta.2026.150213
Parisa Molaeipourashka, Bart van den Bossche, Koen Delaere, Peter Meuris, Aliona Nicolenco, Uxua Huizi, Francisco Alcaide, Eva García-Lecina, Mats Meeusen, Annick Hubin, Mesfin Haile Mamme
Alloy electrodeposition within porous electrodes is governed by strongly coupled transport, kinetics, and geometry, yet these interactions remain poorly understood beyond simplified planar or two-dimensional descriptions. This study presents a three-dimensional multiscale simulation framework, combined with targeted experiments, to resolve the spatial distribution of current density, deposit thickness, and alloy composition during nickel-tungsten electrodeposition in porous carbon cloth. The simulation connects a macro-scale potential description of the electroplating cell to a micro-scale multi-ion transport and reaction formulation that explicitly captures competitive metal deposition within the fiber network. The simulations reveal how macroscopic current partitioning and local transport limitations jointly give rise to pronounced thickness and tungsten composition gradients throughout the porous architecture. Experimental electron microscopy and compositional analysis support these predicted spatial trends across length scales. By directly linking current distribution to local alloy formation in three dimensions, this work provides general insight into the fundamental mechanisms governing induced alloy co-deposition in porous electrodes, extending beyond the specific nickel-tungsten system.
{"title":"A Three-Dimensional Multiscale Simulation Framework for Nickel-Tungsten Electrodeposition in Porous Electrodes","authors":"Parisa Molaeipourashka, Bart van den Bossche, Koen Delaere, Peter Meuris, Aliona Nicolenco, Uxua Huizi, Francisco Alcaide, Eva García-Lecina, Mats Meeusen, Annick Hubin, Mesfin Haile Mamme","doi":"10.1016/j.electacta.2026.150213","DOIUrl":"10.1016/j.electacta.2026.150213","url":null,"abstract":"<div><div>Alloy electrodeposition within porous electrodes is governed by strongly coupled transport, kinetics, and geometry, yet these interactions remain poorly understood beyond simplified planar or two-dimensional descriptions. This study presents a three-dimensional multiscale simulation framework, combined with targeted experiments, to resolve the spatial distribution of current density, deposit thickness, and alloy composition during nickel-tungsten electrodeposition in porous carbon cloth. The simulation connects a macro-scale potential description of the electroplating cell to a micro-scale multi-ion transport and reaction formulation that explicitly captures competitive metal deposition within the fiber network. The simulations reveal how macroscopic current partitioning and local transport limitations jointly give rise to pronounced thickness and tungsten composition gradients throughout the porous architecture. Experimental electron microscopy and compositional analysis support these predicted spatial trends across length scales. By directly linking current distribution to local alloy formation in three dimensions, this work provides general insight into the fundamental mechanisms governing induced alloy co-deposition in porous electrodes, extending beyond the specific nickel-tungsten system.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"581 ","pages":"Article 150213"},"PeriodicalIF":5.8,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149203323","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 : 2026-10-13DOI: 10.1016/j.electacta.2026.150205
Yulia V. Gyrdymova, Jian Zhang, Konstantin S. Rodygin
Ethylene can be produced from acetylene via a simple hydrogenation reaction. Another component for ethylene production is hydrogen, which can be easily produced by water electrolysis. Electrocatalytic hydrogenation of acetylene can be considered as a sustainable approach due to green electricity and lower operation temperatures. This review examines advances in the catalytic selective hydrogenation of acetylene. The selective hydrogenation of acetylene involves dissolution and absorption, electrolysis of water to form hydrogen, hydrogenation of adsorbed acetylene with electro-derived hydrogen, and desorption of ethylene. Each process was used as the core for the sections in this review. Accordingly, each section contains data on the mechanistic investigations, improvements highlighted in the references, and further challenges that need to be addressed. The conclusions section represents a discussion of promising approaches and possible future research directions for improving hydrogenation efficiency.
{"title":"Metal-catalyzed Electrocatalytic Acetylene Semi-hydrogenation: from Mechanistic Insights to Performance Opportunities","authors":"Yulia V. Gyrdymova, Jian Zhang, Konstantin S. Rodygin","doi":"10.1016/j.electacta.2026.150205","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150205","url":null,"abstract":"Ethylene can be produced from acetylene <ce:italic>via</ce:italic> a simple hydrogenation reaction. Another component for ethylene production is hydrogen, which can be easily produced by water electrolysis. Electrocatalytic hydrogenation of acetylene can be considered as a sustainable approach due to green electricity and lower operation temperatures. This review examines advances in the catalytic selective hydrogenation of acetylene. The selective hydrogenation of acetylene involves dissolution and absorption, electrolysis of water to form hydrogen, hydrogenation of adsorbed acetylene with electro-derived hydrogen, and desorption of ethylene. Each process was used as the core for the sections in this review. Accordingly, each section contains data on the mechanistic investigations, improvements highlighted in the references, and further challenges that need to be addressed. The conclusions section represents a discussion of promising approaches and possible future research directions for improving hydrogenation efficiency.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"9 1","pages":"150205"},"PeriodicalIF":6.6,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221594","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 : 2026-10-13DOI: 10.1016/j.electacta.2026.150207
Xuanming Tai, Ning Wang, Wenqi Liu, Bo Pang, Xuemei Wu, Wanting Chen, Gaohong He
Oxygen transport in cathode catalyst layers remains a critical limitation for anion exchange membrane fuel cells (AEMFCs), particularly under low Pt loading. Herein, we propose a molecular cavity engineering strategy by incorporating hydroxyl-rich calixarenes with different cavity sizes (PTBCX, X = 4, 6, and 8) into a polynorbornene-based anion exchange ionomer (QHP). PTBCX facilitates O2 transport through the hydrophobic cavity, while its lower-rim phenolic hydroxyl groups promote interconnected OH⁻ transport pathways, enabling synergistic regulation of O2 transport and OH⁻ conduction. PTBC6, with a moderate cavity size of 0.76 nm, attains the optimal balance between structural modulation and transport performance. At a loading of 15 wt%, PTBC6 increases the ionomer fractional free volume and O2 diffusion coefficient by 65% and 93%, respectively, and delivers a limiting current density of 5.63 mA cm-2, achieving state-of-the-art performance among reported alkaline ORR systems. Furthermore, under a low cathode Pt loading of 0.1 mgPt cm-2, the H2/O2 single cell delivers a peak power density of 561.3 mW cm-2, which is 75% higher than that of pristine QHP. These results demonstrate that calixarene-based molecular cavity engineering provides an effective strategy for enhancing mass transport in low-Pt AEMFC cathodes.
阴极催化剂层中的氧传输仍然是阴离子交换膜燃料电池（aemfc）的一个关键限制，特别是在低Pt负载下。在此，我们提出了一种分子空腔工程策略，将不同空腔大小的富羟基杯芳烃（PTBCX, X = 4,6和8）加入到聚降木片烯阴离子交换离聚体（QHP）中。PTBCX促进O2通过疏水腔的运输，而它的下缘酚羟基促进相互连接的OH -运输途径，使O2运输和OH -传导协同调节。PTBC6实现了结构调制和传输性能之间的最佳平衡，其空腔尺寸为0.76 nm。当负载为15wt %时，PTBC6可将离子单体的自由体积分数和O2扩散系数分别提高65%和93%，并提供5.63 mA cm-2的极限电流密度，在已有报道的碱性ORR系统中达到了最先进的性能。此外，在低阴极Pt负载为0.1 mgPt cm-2的情况下，H2/O2单体电池的峰值功率密度为561.3 mW cm-2，比原始QHP高出75%。这些结果表明，基于杯芳烃的分子腔工程为提高低pt AEMFC阴极的质量输运提供了有效的策略。
{"title":"Calixarene-Regulated Ionomer Microenvironments for Enhanced Oxygen Transport in AEMFC Cathodes","authors":"Xuanming Tai, Ning Wang, Wenqi Liu, Bo Pang, Xuemei Wu, Wanting Chen, Gaohong He","doi":"10.1016/j.electacta.2026.150207","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150207","url":null,"abstract":"Oxygen transport in cathode catalyst layers remains a critical limitation for anion exchange membrane fuel cells (AEMFCs), particularly under low Pt loading. Herein, we propose a molecular cavity engineering strategy by incorporating hydroxyl-rich calixarenes with different cavity sizes (PTBCX, X = 4, 6, and 8) into a polynorbornene-based anion exchange ionomer (QHP). PTBCX facilitates O<ce:inf loc=\"post\">2</ce:inf> transport through the hydrophobic cavity, while its lower-rim phenolic hydroxyl groups promote interconnected OH⁻ transport pathways, enabling synergistic regulation of O<ce:inf loc=\"post\">2</ce:inf> transport and OH⁻ conduction. PTBC6, with a moderate cavity size of 0.76 nm, attains the optimal balance between structural modulation and transport performance. At a loading of 15 wt%, PTBC6 increases the ionomer fractional free volume and O<ce:inf loc=\"post\">2</ce:inf> diffusion coefficient by 65% and 93%, respectively, and delivers a limiting current density of 5.63 mA cm<ce:sup loc=\"post\">-2</ce:sup>, achieving state-of-the-art performance among reported alkaline ORR systems. Furthermore, under a low cathode Pt loading of 0.1 mg<ce:inf loc=\"post\">Pt</ce:inf> cm<ce:sup loc=\"post\">-2</ce:sup>, the H<ce:inf loc=\"post\">2</ce:inf>/O<ce:inf loc=\"post\">2</ce:inf> single cell delivers a peak power density of 561.3 mW cm<ce:sup loc=\"post\">-2</ce:sup>, which is 75% higher than that of pristine QHP. These results demonstrate that calixarene-based molecular cavity engineering provides an effective strategy for enhancing mass transport in low-Pt AEMFC cathodes.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"50 1","pages":"150207"},"PeriodicalIF":6.6,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221595","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 : 2026-10-13DOI: 10.1016/j.electacta.2026.150202
Xin Yuan, Zizhen Cui, Shuai Su, Hengyu Zhao
Seawater microdroplets (10–40 μm) in the marine splash zone accelerate carbon-steel corrosion to about five times the bulk-immersion rate, with local enhancement up to 12.45-fold at the three-phase boundary, accompanied by reactive oxygen species (·OH, H₂O₂). A coupled thermodynamic–electrokinetic–homogeneous kinetic and two-dimensional transport theory is developed. The OH⁻ self-oxidation route is thermodynamically forbidden (ΔG=+221.9 kJ/mol), whereas the Fe-driven stepwise O₂ reduction chain is spontaneous (ΔG=−164.8 kJ/mol), identifying ROS as corrosion-chain intermediates. nM-level ·OH cannot sustain an electrode current and acts chemically through FeOOH depassivation. Mechanism decomposition assigns 70.3% of the 5.16-fold enhancement to classical thin-film transport and 29.7% to radical depassivation; a dimensionally closed six-species model and leave-one-out cross-validation (LOOCV, MAPE=7.3%, R²=0.98) and a parameter-free 2D thin-film simulation (contact-line/center=2.85×) agree with independent experiments.
{"title":"Thermodynamic–kinetic–multiphysics theory of carbon steel corrosion accelerated by seawater microdroplets: Quantitative dissection from electrochemical potential gradient to radical depassivation","authors":"Xin Yuan, Zizhen Cui, Shuai Su, Hengyu Zhao","doi":"10.1016/j.electacta.2026.150202","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150202","url":null,"abstract":"Seawater microdroplets (10–40 μm) in the marine splash zone accelerate carbon-steel corrosion to about five times the bulk-immersion rate, with local enhancement up to 12.45-fold at the three-phase boundary, accompanied by reactive oxygen species (·OH, H₂O₂). A coupled thermodynamic–electrokinetic–homogeneous kinetic and two-dimensional transport theory is developed. The OH⁻ self-oxidation route is thermodynamically forbidden (ΔG=+221.9 kJ/mol), whereas the Fe-driven stepwise O₂ reduction chain is spontaneous (ΔG=−164.8 kJ/mol), identifying ROS as corrosion-chain intermediates. nM-level ·OH cannot sustain an electrode current and acts chemically through FeOOH depassivation. Mechanism decomposition assigns 70.3% of the 5.16-fold enhancement to classical thin-film transport and 29.7% to radical depassivation; a dimensionally closed six-species model and leave-one-out cross-validation (LOOCV, MAPE=7.3%, R²=0.98) and a parameter-free 2D thin-film simulation (contact-line/center=2.85×) agree with independent experiments.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":"150202"},"PeriodicalIF":6.6,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221596","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 : 2026-10-13DOI: 10.1016/j.electacta.2026.150208
Chaofei Lan, Shanpeng Pei, Yi Zhang, Jin Zhao, Xiaoyu An, Ziqi Zhang, Wei Huang, Songyan Chen
Dynamic electrochemical impedance spectroscopy (DEIS) shows strong potential for online state estimation of lithium-ion batteries (LIBs), yet its practical application remains limited by the interplay among relaxation, temperature, transient operating conditions, and historical cell states. In this work, the differences between stationary electrochemical impedance spectroscopy (SEIS) and DEIS are systematically investigated using a single commercial 18650 cell. First, DEIS measured shortly after discharge is analyzed. Within the investigated post-discharge period and experimental resolution, temperature variation accounts for most of the observable impedance evolution, whereas an independent relaxation contribution is not resolved. The coupled effects of transient current and temperature on operando DEIS are then examined using a simplified characteristic-feature framework intended to approximately separate their contributions. In addition, SEIS hysteresis is observed, indicating that the impedance measured after a long rest depends not only on the present state of charge (SOC) but also on the preceding operating history. Accordingly, a normalization strategy based on the ratio of the dynamic impedance feature to its corresponding local SEIS reference is evaluated and produces more consistent qualitative trends across the tested historical conditions and SOC levels. These results provide a novel perspective on the effects of temperature, transient current, and historical state on DEIS, offer useful guidance for developing DEIS-based online state-estimation methods for LIBs, and establish a basis for further quantitative validation using additional cells and operating conditions.
{"title":"Understanding Temperature, Transient-Current, and Historical-State Effects in Dynamic Electrochemical Impedance Spectroscopy of Lithium-Ion Batteries","authors":"Chaofei Lan, Shanpeng Pei, Yi Zhang, Jin Zhao, Xiaoyu An, Ziqi Zhang, Wei Huang, Songyan Chen","doi":"10.1016/j.electacta.2026.150208","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150208","url":null,"abstract":"Dynamic electrochemical impedance spectroscopy (DEIS) shows strong potential for online state estimation of lithium-ion batteries (LIBs), yet its practical application remains limited by the interplay among relaxation, temperature, transient operating conditions, and historical cell states. In this work, the differences between stationary electrochemical impedance spectroscopy (SEIS) and DEIS are systematically investigated using a single commercial 18650 cell. First, DEIS measured shortly after discharge is analyzed. Within the investigated post-discharge period and experimental resolution, temperature variation accounts for most of the observable impedance evolution, whereas an independent relaxation contribution is not resolved. The coupled effects of transient current and temperature on operando DEIS are then examined using a simplified characteristic-feature framework intended to approximately separate their contributions. In addition, SEIS hysteresis is observed, indicating that the impedance measured after a long rest depends not only on the present state of charge (SOC) but also on the preceding operating history. Accordingly, a normalization strategy based on the ratio of the dynamic impedance feature to its corresponding local SEIS reference is evaluated and produces more consistent qualitative trends across the tested historical conditions and SOC levels. These results provide a novel perspective on the effects of temperature, transient current, and historical state on DEIS, offer useful guidance for developing DEIS-based online state-estimation methods for LIBs, and establish a basis for further quantitative validation using additional cells and operating conditions.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"12 1","pages":"150208"},"PeriodicalIF":6.6,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221597","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}
Multiscale structural regulation is critical for improving ion accessibility and redox utilization in layered double hydroxide (LDH) electrodes. Here, cetyltrimethylammonium bromide (CTAB) was introduced into a one-step hydrothermal process to simultaneously regulate the particle size and interlayer spacing of NiMn-LDH nanoflowers. Increasing the CTAB dosage reduced the particle diameter from approximately 1.5 µm to 266 nm while enlarging the interlayer spacing from 9.45 to 9.68 Å. The optimized NML-2C exhibited a core-shell nanoflower architecture, a BET surface area of 143.4 m2 g−1, and an interlayer spacing of 9.60 Å, providing abundant accessible sites and shortened ion-transport pathways. Consequently, NML-2C delivered a specific capacity of 946.5 C g−1 at 1 A g−1 and retained 677.0 C g−1 at 20 A g−1, with 87.5% capacity retention after 5500 cycles. Density functional theory calculations indicated that the enlarged interlayer spacing strengthens OH⁻ adsorption and facilitates interfacial Faradaic reactions. Moreover, the flexible asymmetric hybrid supercapacitor achieved an energy density of 51.0 Wh kg−1 at a power density of 800.2 W kg−1 and retained 88.4% capacitance after 12,000 cycles. These results demonstrate that surfactant-assisted simultaneous regulation of particle architecture and interlayer spacing provides an effective strategy for developing high-performance NiMn-LDH electrodes for flexible electrochemical energy-storage devices.
多尺度结构调控是提高层状双氢氧化物（LDH）电极离子可及性和氧化还原利用率的关键。本研究将十六烷基三甲基溴化铵（CTAB）引入一步水热工艺，同时调节NiMn-LDH纳米花的粒径和层间距。随着CTAB用量的增加，颗粒直径从约1.5µm减小到266 nm，层间距从9.45增大到9.68 Å。优化后的NML-2C具有核壳纳米花结构，BET表面积为143.4 m2 g−1，层间间距为9.60 Å，具有丰富的可达位点和缩短的离子传输途径。因此，NML-2C在1 a g−1下的比容量为946.5 C g−1，在20 a g−1下的比容量为677.0 C g−1，在5500次循环后容量保留率为87.5%。密度泛函理论计算表明，层间距的增大加强了OH -吸附，促进了界面法拉第反应。此外，该柔性非对称混合超级电容器在功率密度为800.2 W kg - 1时，能量密度达到51.0 Wh kg - 1，在循环12,000次后保持了88.4%的电容。这些结果表明，表面活性剂辅助的粒子结构和层间距的同时调节为柔性电化学储能装置开发高性能NiMn-LDH电极提供了有效的策略。
{"title":"Surfactant-Mediated Regulation of Interlayer Spacing and Hierarchical Architecture in NiMn-LDH Nanoflowers for High-Performance Flexible Supercapacitors","authors":"Ziyun Zhang, Mingru Sun, Zichuan Liu, Lingli Cheng, Zheng Jiao","doi":"10.1016/j.electacta.2026.150189","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150189","url":null,"abstract":"Multiscale structural regulation is critical for improving ion accessibility and redox utilization in layered double hydroxide (LDH) electrodes. Here, cetyltrimethylammonium bromide (CTAB) was introduced into a one-step hydrothermal process to simultaneously regulate the particle size and interlayer spacing of NiMn-LDH nanoflowers. Increasing the CTAB dosage reduced the particle diameter from approximately 1.5 µm to 266 nm while enlarging the interlayer spacing from 9.45 to 9.68 Å. The optimized NML-2C exhibited a core-shell nanoflower architecture, a BET surface area of 143.4 m<ce:sup loc=\"post\">2</ce:sup> g<ce:sup loc=\"post\">−1</ce:sup>, and an interlayer spacing of 9.60 Å, providing abundant accessible sites and shortened ion-transport pathways. Consequently, NML-2C delivered a specific capacity of 946.5 C g<ce:sup loc=\"post\">−1</ce:sup> at 1 A g<ce:sup loc=\"post\">−1</ce:sup> and retained 677.0 C g<ce:sup loc=\"post\">−1</ce:sup> at 20 A g<ce:sup loc=\"post\">−1</ce:sup>, with 87.5% capacity retention after 5500 cycles. Density functional theory calculations indicated that the enlarged interlayer spacing strengthens OH⁻ adsorption and facilitates interfacial Faradaic reactions. Moreover, the flexible asymmetric hybrid supercapacitor achieved an energy density of 51.0 Wh kg<ce:sup loc=\"post\">−1</ce:sup> at a power density of 800.2 W kg<ce:sup loc=\"post\">−1</ce:sup> and retained 88.4% capacitance after 12,000 cycles. These results demonstrate that surfactant-assisted simultaneous regulation of particle architecture and interlayer spacing provides an effective strategy for developing high-performance NiMn-LDH electrodes for flexible electrochemical energy-storage devices.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"44 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221463","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 effects of sodium bis(3-sulfopropyl) disulfide, disodium salt (SPS) on nickel coatings electrodeposited from a nickel-sulfamate bath were investigated by microstructural characterization and electrochemical measurements. The addition of 0.10 g·L⁻¹ SPS transformed the coating surface from a relatively flat morphology to a cauliflower-like structure and increased the surface roughness, while reducing the average grain size from 4.0 to 0.4 μm. Meanwhile, the compressive residual stress was relaxed from approximately −160 to −60 MPa. X-ray diffraction results showed that SPS suppressed the pronounced (200) texture of the additive-free coating and increased the relative contributions of the (111) and (220) orientations, resulting in a more balanced crystallographic orientation distribution. Electrochemically, SPS shifted the onset potential for Ni²⁺ reduction by approximately 0.10 V toward less-negative values and increased the cathodic current density by up to 2.8-fold at −0.80 V, while the current efficiency remained close to 100%. Analysis of the normalized chronoamperometric transients suggested that SPS shifted nickel deposition toward predominantly instantaneous nucleation at relatively low overpotentials. Anodic polarization and surface analyses further indicated that SPS increased the anodic current in the nominal passive-potential region and reduced the relative contribution of oxidized nickel species on the anode surface. These results suggest that SPS modifies both cathodic nucleation behavior and anodic surface oxidation, while rapid nucleation coupled with mass-transport-influenced growth contributes to grain refinement and residual-stress relaxation.
{"title":"Influence of bis(3-sulfopropyl) disulfide on the electrodeposition behavior and microstructure of Ni coatings from a sulfamate bath","authors":"Wenchao Li, Hu Tian, Ying Jin, Boyuan Ran, Shilong Chen, Feifei Huang","doi":"10.1016/j.electacta.2026.150198","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150198","url":null,"abstract":"The effects of sodium bis(3-sulfopropyl) disulfide, disodium salt (SPS) on nickel coatings electrodeposited from a nickel-sulfamate bath were investigated by microstructural characterization and electrochemical measurements. The addition of 0.10 g·L⁻¹ SPS transformed the coating surface from a relatively flat morphology to a cauliflower-like structure and increased the surface roughness, while reducing the average grain size from 4.0 to 0.4 μm. Meanwhile, the compressive residual stress was relaxed from approximately −160 to −60 MPa. X-ray diffraction results showed that SPS suppressed the pronounced (200) texture of the additive-free coating and increased the relative contributions of the (111) and (220) orientations, resulting in a more balanced crystallographic orientation distribution. Electrochemically, SPS shifted the onset potential for Ni²⁺ reduction by approximately 0.10 V toward less-negative values and increased the cathodic current density by up to 2.8-fold at −0.80 V, while the current efficiency remained close to 100%. Analysis of the normalized chronoamperometric transients suggested that SPS shifted nickel deposition toward predominantly instantaneous nucleation at relatively low overpotentials. Anodic polarization and surface analyses further indicated that SPS increased the anodic current in the nominal passive-potential region and reduced the relative contribution of oxidized nickel species on the anode surface. These results suggest that SPS modifies both cathodic nucleation behavior and anodic surface oxidation, while rapid nucleation coupled with mass-transport-influenced growth contributes to grain refinement and residual-stress relaxation.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"44 1","pages":"150198"},"PeriodicalIF":6.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221611","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 : 2026-10-03DOI: 10.1016/j.electacta.2026.150146
Hooman Hadidi
Hourglass nanochannels provide a confined throat where geometric focusing and soft fixed charge can interact strongly. However, the role of spatially patterned polyelectrolyte layers (PELs) in controlling transport through this junction remains insufficiently resolved. Here, ionic current rectification is investigated using coupled Poisson–Nernst–Planck and Stokes–Brinkman/Navier–Stokes simulations for uniform, convergent-only, and bipolar PEL architectures. The results show that the hourglass throat acts as a localized electrostatic–hydrodynamic gate. In the bipolar configuration, oppositely charged PEL domains form an internal soft junction that switches with voltage polarity between a strongly depleted, low-conductance state and an enriched, high-conductance state. This switching is traced to the coupled effects of concentration polarization, electrostatic selectivity, electric-field localization, and throat-focused electrohydrodynamic flow. The PEL fixed-charge density exhibits an optimum rather than a monotonic effect, yielding a peak rectification factor of approximately 1120 within the charge-density sweep at a bulk electrolyte concentration of 0.3 mol/m³ for the reference geometry with a convergent angle of 4.57°. The geometry provides an additional control mechanism: changing the convergent-section length can reverse the preferred transport direction. In a separate convergent-angle sweep conducted at a bulk electrolyte concentration of 10 mol/m³, decreasing the convergent angle from 20° to 4.57° increases the rectification factor from approximately 470 to 1630. These results establish the hourglass throat as a tunable soft junction for controlling both the magnitude and polarity of ionic current rectification.
{"title":"Throat-gated ionic current rectification in soft-layer hourglass nanochannels","authors":"Hooman Hadidi","doi":"10.1016/j.electacta.2026.150146","DOIUrl":"https://doi.org/10.1016/j.electacta.2026.150146","url":null,"abstract":"Hourglass nanochannels provide a confined throat where geometric focusing and soft fixed charge can interact strongly. However, the role of spatially patterned polyelectrolyte layers (PELs) in controlling transport through this junction remains insufficiently resolved. Here, ionic current rectification is investigated using coupled Poisson–Nernst–Planck and Stokes–Brinkman/Navier–Stokes simulations for uniform, convergent-only, and bipolar PEL architectures. The results show that the hourglass throat acts as a localized electrostatic–hydrodynamic gate. In the bipolar configuration, oppositely charged PEL domains form an internal soft junction that switches with voltage polarity between a strongly depleted, low-conductance state and an enriched, high-conductance state. This switching is traced to the coupled effects of concentration polarization, electrostatic selectivity, electric-field localization, and throat-focused electrohydrodynamic flow. The PEL fixed-charge density exhibits an optimum rather than a monotonic effect, yielding a peak rectification factor of approximately 1120 within the charge-density sweep at a bulk electrolyte concentration of 0.3 mol/m³ for the reference geometry with a convergent angle of 4.57°. The geometry provides an additional control mechanism: changing the convergent-section length can reverse the preferred transport direction. In a separate convergent-angle sweep conducted at a bulk electrolyte concentration of 10 mol/m³, decreasing the convergent angle from 20° to 4.57° increases the rectification factor from approximately 470 to 1630. These results establish the hourglass throat as a tunable soft junction for controlling both the magnitude and polarity of ionic current rectification.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"52 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149123858","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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