Pub Date : 2022-11-23DOI: 10.33961/jecst.2022.00479
Jian Yao, Fa-yi Yan, Xu Pei
Proton exchange membrane fuel cell (PEMFC) is a portable and clean power generation device. The structural arrangement of the flow field has a significant influence on the delivery efficiency of PEMFC. In this article, a new bionic flow channel is designed based on the inspiration of a spider shape. The branch channel width and branch corner are studied as the focus, and its simulation is carried out by the method of computational fluid dynamics (CFD). The results show that when channel width/rib width and corner of the branch are 1.5 and 130 o , respectively, it is the best numerical combination and the cell comprehensive performance is excellent. The final model using this numerical combination is compared with the traditional flow channel model to verify the advancement of this scheme.
{"title":"Design and Analysis of Spider Bionic Flow Field for Proton Exchange Membrane Fuel Cell","authors":"Jian Yao, Fa-yi Yan, Xu Pei","doi":"10.33961/jecst.2022.00479","DOIUrl":"https://doi.org/10.33961/jecst.2022.00479","url":null,"abstract":"Proton exchange membrane fuel cell (PEMFC) is a portable and clean power generation device. The structural arrangement of the flow field has a significant influence on the delivery efficiency of PEMFC. In this article, a new bionic flow channel is designed based on the inspiration of a spider shape. The branch channel width and branch corner are studied as the focus, and its simulation is carried out by the method of computational fluid dynamics (CFD). The results show that when channel width/rib width and corner of the branch are 1.5 and 130 o , respectively, it is the best numerical combination and the cell comprehensive performance is excellent. The final model using this numerical combination is compared with the traditional flow channel model to verify the advancement of this scheme.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48334611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-23DOI: 10.33961/jecst.2022.00661
Oguz Özbek, M. Gürdere, Caglar Berkel, Ö. Isildak
In this study, a new potentiometric sensor selective to copper(II) ions was developed and characterized. The developed sensor has a polymeric membrane and contains 4.0% electroactive material (ionophore), 33.0% poly(vinyl chloride) (PVC), 63.0% bis(2–ethylhexyl)sebacate (BEHS) and 1.0% potassium tetrakis( p –chlorophenyl)borate (KT p ClPB). This novel cop-per(II)–selective sensor exhibits a Nernstian response over a wide concentration range from 1.0×10 -6 to 1.0×10 -1 mol L -1 with a slope of 29.6 (±1.2) mV decade -1 , and a lower detection limit of 8.75×10 -7 mol L -1 . The sensor, which was pro-duced economically by synthesizing the ionophore in the laboratory, has a good selectivity and repeatability, fast response time and stable potentiometric behaviour. The potential response of the sensor remains unaffected of pH in the range of 5.0–10.0. Based on the analytical applications of the sensor, we showed that it can be used as an indicator electrode in the quantification of Cu 2+ ions by potentiometric titration against EDTA, and can also be successfully utilized for the determination of copper(II) ions in different real samples.
本研究研制了一种新型铜离子选择性电位传感器，并对其进行了表征。所开发的传感器具有聚合物膜，含有4.0%电活性物质(离子载体)，33.0%聚氯乙烯(PVC)， 63.0%双(2 -乙基己基)癸二酸酯(BEHS)和1.0%四烷基(对氯苯基)硼酸钾(KT p ClPB)。这种新型的铜-per(II)选择性传感器在1.0×10 -6至1.0×10 -1 mol L -1的宽浓度范围内表现出Nernstian响应，斜率为29.6(±1.2)mV decade -1，检测限为8.75×10 -7 mol L -1。该传感器具有良好的选择性和重复性、快速的响应时间和稳定的电位行为。在5.0-10.0范围内，传感器的电位响应不受pH的影响。基于该传感器的分析应用，我们证明了它可以作为指示电极用于EDTA电位滴定法定量cu2 +离子，也可以成功地用于不同实际样品中铜(II)离子的测定。
{"title":"Electroanalytical Determination of Copper(II) Ions Using a Polymer Membrane Sensor","authors":"Oguz Özbek, M. Gürdere, Caglar Berkel, Ö. Isildak","doi":"10.33961/jecst.2022.00661","DOIUrl":"https://doi.org/10.33961/jecst.2022.00661","url":null,"abstract":"In this study, a new potentiometric sensor selective to copper(II) ions was developed and characterized. The developed sensor has a polymeric membrane and contains 4.0% electroactive material (ionophore), 33.0% poly(vinyl chloride) (PVC), 63.0% bis(2–ethylhexyl)sebacate (BEHS) and 1.0% potassium tetrakis( p –chlorophenyl)borate (KT p ClPB). This novel cop-per(II)–selective sensor exhibits a Nernstian response over a wide concentration range from 1.0×10 -6 to 1.0×10 -1 mol L -1 with a slope of 29.6 (±1.2) mV decade -1 , and a lower detection limit of 8.75×10 -7 mol L -1 . The sensor, which was pro-duced economically by synthesizing the ionophore in the laboratory, has a good selectivity and repeatability, fast response time and stable potentiometric behaviour. The potential response of the sensor remains unaffected of pH in the range of 5.0–10.0. Based on the analytical applications of the sensor, we showed that it can be used as an indicator electrode in the quantification of Cu 2+ ions by potentiometric titration against EDTA, and can also be successfully utilized for the determination of copper(II) ions in different real samples.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41824734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-21DOI: 10.33961/jecst.2022.00619
Hyo-Young Kim, Ji-Woo Park, Seo Jeong Yoon, In‐Yup Jeon, Young-Wan Ju
Owing to the rapid climate change, a high-performance energy storage system (ESS) for efficient energy consumption has been receiving considerable attention. ESS, such as capacitors, usually has issues with the ion diffusion of electrode materials, resulting in a decrease in their capacitance. Notably, appropriate pore diameter and large specific surface area (SSA) may result in an effective ion diffusion. Therefore, graphene and multi-walled carbon nanotube (graphene@MWCNT) hybrid nanomaterials, with covalent bonds between the graphene and MWCNT, were prepared via an edge-chemistry reaction. The properties of these materials, such as high porosity, large SSA, and high electroconductivity, make them suitable to be used as electrode materials for capacitors. The optimal ratio of graphene to MWCNT can affect the electrochemical performance of the electrode material based on its physical and electrochemical properties. The supercapacitor using optimal graphene-based hybrid electrode material exhibited highest specific capacitance value as 158 F/g and excellent cycle stability.
{"title":"Effect of Edge-Chemistry on Graphene-Based Hybrid Electrode Materials for Energy Storage Device","authors":"Hyo-Young Kim, Ji-Woo Park, Seo Jeong Yoon, In‐Yup Jeon, Young-Wan Ju","doi":"10.33961/jecst.2022.00619","DOIUrl":"https://doi.org/10.33961/jecst.2022.00619","url":null,"abstract":"Owing to the rapid climate change, a high-performance energy storage system (ESS) for efficient energy consumption has been receiving considerable attention. ESS, such as capacitors, usually has issues with the ion diffusion of electrode materials, resulting in a decrease in their capacitance. Notably, appropriate pore diameter and large specific surface area (SSA) may result in an effective ion diffusion. Therefore, graphene and multi-walled carbon nanotube (graphene@MWCNT) hybrid nanomaterials, with covalent bonds between the graphene and MWCNT, were prepared via an edge-chemistry reaction. The properties of these materials, such as high porosity, large SSA, and high electroconductivity, make them suitable to be used as electrode materials for capacitors. The optimal ratio of graphene to MWCNT can affect the electrochemical performance of the electrode material based on its physical and electrochemical properties. The supercapacitor using optimal graphene-based hybrid electrode material exhibited highest specific capacitance value as 158 F/g and excellent cycle stability.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48307363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-12DOI: 10.33961/jecst.2022.00514
Hyein Lee, Young Jun Kim, Young-Dong Sohn, C. Rhee
This work presents a correlation between the behavior of formic acid oxidation (FAO) on various Bi-modified Pt(poly) disk electrodes and their morphologies observed on Bi-modified Pt(111) disk electrodes using electrochemical scanning tunneling microscopy (EC-STM) to understand the effects of Bi on Pt. To distinguish the FAO activities of Bi on Pt and plain Pt around Bi, additional Pt was intentionally deposited using two different routes: direct route and iodine route. In direct route, Pt was directly deposited on Bi islands and plain Pt sites around Bi islands, while in iodine route, Pt was exclusively deposited on Bi islands by protecting plain Pt sites with adsorbed iodine. Thus, a comparison of FAO performances on the two Bi-modified Pt electrodes with additional Pt (deposited in the different ways) disclosed a difference in FAO performances on plain Pt sites and Bi islands. When Bi coverage was ~0.04, the Bi deposits were scattered Bi islands enhancing FAO on Pt(poly). The additional Pt deposits using direct route increased FAO efficiency, while the ones using iodine route slightly decreased FAO current. The EC-STM observations indicated that Pt deposits around Bi islands, not on Bi islands, were responsible for the FAO current increase on Bi-modified Pt(poly). The FAO efficiency on Bi-modified Pt(poly) with a Bi coverage of ~0.25 increased by a factor of 2. However, the additional Pt deposits using the two Pt deposition routes notably decreased the FAO current. The dependency of FAO on Bi coverage was discussed in terms of electronic effect and ensemble effect.
{"title":"The Ways for Bi on Pt to Enhance Formic Acid Oxidation","authors":"Hyein Lee, Young Jun Kim, Young-Dong Sohn, C. Rhee","doi":"10.33961/jecst.2022.00514","DOIUrl":"https://doi.org/10.33961/jecst.2022.00514","url":null,"abstract":"This work presents a correlation between the behavior of formic acid oxidation (FAO) on various Bi-modified Pt(poly) disk electrodes and their morphologies observed on Bi-modified Pt(111) disk electrodes using electrochemical scanning tunneling microscopy (EC-STM) to understand the effects of Bi on Pt. To distinguish the FAO activities of Bi on Pt and plain Pt around Bi, additional Pt was intentionally deposited using two different routes: direct route and iodine route. In direct route, Pt was directly deposited on Bi islands and plain Pt sites around Bi islands, while in iodine route, Pt was exclusively deposited on Bi islands by protecting plain Pt sites with adsorbed iodine. Thus, a comparison of FAO performances on the two Bi-modified Pt electrodes with additional Pt (deposited in the different ways) disclosed a difference in FAO performances on plain Pt sites and Bi islands. When Bi coverage was ~0.04, the Bi deposits were scattered Bi islands enhancing FAO on Pt(poly). The additional Pt deposits using direct route increased FAO efficiency, while the ones using iodine route slightly decreased FAO current. The EC-STM observations indicated that Pt deposits around Bi islands, not on Bi islands, were responsible for the FAO current increase on Bi-modified Pt(poly). The FAO efficiency on Bi-modified Pt(poly) with a Bi coverage of ~0.25 increased by a factor of 2. However, the additional Pt deposits using the two Pt deposition routes notably decreased the FAO current. The dependency of FAO on Bi coverage was discussed in terms of electronic effect and ensemble effect.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41634521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-12DOI: 10.33961/jecst.2022.00570
J. Jang, Jihee Kim, Churl-Kyoung Lee, K. Kwon
Ionic liquids are considered as a promising, alternative solvent for the electrochemical synthesis of metals because of their high thermal and chemical stability, relatively high ionic conductivity, and wide electrochemical window. In particular, their wide electrochemical window enables the electrodeposition of metals without any side reaction of electrolytes such as hydrogen evolution. The electrodeposition of silver is conducted in 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) ionic liquid system with a silver source of AgCl. This study is the first attempt to electrodeposit silver nanoparticles without using co-solvents other than [C4mim]Cl. Pulse electrolysis is employed for the synthesis of silver nanoparticles by varying applied potentials from -3.0 V to -4.5 V ( vs. Pt-quasi reference electrode) and pulse duration from 0.1 s to 0.7 s. Accord-ingly, the silver nanoparticles whose size ranges from 15 nm to ~100 nm are obtained. The successful preparation of silver nanoparticles is demonstrated regardless of the kinds of substrate including aluminum, stainless steel, and carbon paper in the pulse electrolysis. Finally, the antimicrobial property of electrodeposited silver nanoparticles is confirmed by an antimicrobial test using Staphylococcus aureus.
{"title":"Synthesis of Silver Nanoparticles using Pulse Electrolysis in 1-n-butyl-3-methylimidazolium Chloride Ionic Liquid","authors":"J. Jang, Jihee Kim, Churl-Kyoung Lee, K. Kwon","doi":"10.33961/jecst.2022.00570","DOIUrl":"https://doi.org/10.33961/jecst.2022.00570","url":null,"abstract":"Ionic liquids are considered as a promising, alternative solvent for the electrochemical synthesis of metals because of their high thermal and chemical stability, relatively high ionic conductivity, and wide electrochemical window. In particular, their wide electrochemical window enables the electrodeposition of metals without any side reaction of electrolytes such as hydrogen evolution. The electrodeposition of silver is conducted in 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) ionic liquid system with a silver source of AgCl. This study is the first attempt to electrodeposit silver nanoparticles without using co-solvents other than [C4mim]Cl. Pulse electrolysis is employed for the synthesis of silver nanoparticles by varying applied potentials from -3.0 V to -4.5 V ( vs. Pt-quasi reference electrode) and pulse duration from 0.1 s to 0.7 s. Accord-ingly, the silver nanoparticles whose size ranges from 15 nm to ~100 nm are obtained. The successful preparation of silver nanoparticles is demonstrated regardless of the kinds of substrate including aluminum, stainless steel, and carbon paper in the pulse electrolysis. Finally, the antimicrobial property of electrodeposited silver nanoparticles is confirmed by an antimicrobial test using Staphylococcus aureus.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42085675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-29DOI: 10.33961/jecst.2022.00395
Pankaj Chauhan, B. Lal
Spinel ferrites (Ni x Fe 3-x O 4 ; x = 0.25, 0.5, 0.75 and 1.0) have been prepared at 550ºC by egg white auto-combustion route using egg white at 550ºC and characterized by physicochemical (TGA, IR, XRD, and SEM) and electrochemical (CV and Tafel polarization) techniques. The presence of characteristic vibration peaks in FT-IR and reflection planes in XRD spectra confirmed the formation of spinel ferrites. The prepared oxides were transformed into oxide film on glassy carbon electrodes by coating oxide powder ink using the nafion solution and investigated their electrocatalytic performance for OER in an alkaline solution. The cyclic voltammograms of the oxide electrode did not show any redox peaks in oxygen overpotential regions. The iR-free Tafel polarization curves exhibited two Tafel slopes (b 1 = 59–90 mV decade -1 and b 2 = 92– 124 mV decade -1 ) in lower and higher over potential regions, respectively. Ni-substitution in oxide matrix significantly improved the electrocatalytic activity for oxygen evolution reaction. Based on the current density for OER, the 0.75 mol Ni-substituted oxide electrode was found to be the most active electrode among the prepared oxides and showed the highest value of apparent current density (~9 mA cm -2 at 0.85 V) and lowest Tafel slope (59 mV decade -1 ). The OER on oxide electrodes occurred via the formation of chemisorbed intermediate on the active sites of the oxide electrode and follow the sec-ond-order mechanism.
采用蛋清自燃烧法在550℃下制备了尖晶石铁氧体（Ni x Fe 3-x O 4；x=0.25、0.5、0.75和1.0），并通过物理化学（TGA、IR、XRD和SEM）和电化学（CV和Tafel极化）技术进行了表征。FT-IR和XRD光谱中反射面的特征振动峰的存在证实了尖晶石铁氧体的形成。通过用nafion溶液涂覆氧化物粉末油墨，将制备的氧化物在玻碳电极上转化为氧化物膜，并研究了它们在碱性溶液中对OER的电催化性能。氧化物电极的循环伏安图在氧过电位区域中没有显示任何氧化还原峰。无iR的Tafel极化曲线在较低和较高过电位区域分别表现出两个Tafel斜率（b1=59–90 mV decade-1和b2=92–124 mV decade-1）。氧化物基体中的Ni取代显著提高了析氧反应的电催化活性。基于OER的电流密度，发现0.75mol Ni取代的氧化物电极是所制备的氧化物中最活性的电极，并且显示出最高的表观电流密度值（在0.85V时~9mA cm-2）和最低的Tafel斜率（59mV decel-1）。氧化物电极上的OER是通过在氧化物电极的活性位点上形成化学吸附的中间体而发生的，并且遵循二阶机制。
{"title":"Electrochemical Oxygen Evolution Reaction on NixFe3-xO4 (0 ≤ x ≤ 1.0) in Alkaline Medium at 25ºC","authors":"Pankaj Chauhan, B. Lal","doi":"10.33961/jecst.2022.00395","DOIUrl":"https://doi.org/10.33961/jecst.2022.00395","url":null,"abstract":"Spinel ferrites (Ni x Fe 3-x O 4 ; x = 0.25, 0.5, 0.75 and 1.0) have been prepared at 550ºC by egg white auto-combustion route using egg white at 550ºC and characterized by physicochemical (TGA, IR, XRD, and SEM) and electrochemical (CV and Tafel polarization) techniques. The presence of characteristic vibration peaks in FT-IR and reflection planes in XRD spectra confirmed the formation of spinel ferrites. The prepared oxides were transformed into oxide film on glassy carbon electrodes by coating oxide powder ink using the nafion solution and investigated their electrocatalytic performance for OER in an alkaline solution. The cyclic voltammograms of the oxide electrode did not show any redox peaks in oxygen overpotential regions. The iR-free Tafel polarization curves exhibited two Tafel slopes (b 1 = 59–90 mV decade -1 and b 2 = 92– 124 mV decade -1 ) in lower and higher over potential regions, respectively. Ni-substitution in oxide matrix significantly improved the electrocatalytic activity for oxygen evolution reaction. Based on the current density for OER, the 0.75 mol Ni-substituted oxide electrode was found to be the most active electrode among the prepared oxides and showed the highest value of apparent current density (~9 mA cm -2 at 0.85 V) and lowest Tafel slope (59 mV decade -1 ). The OER on oxide electrodes occurred via the formation of chemisorbed intermediate on the active sites of the oxide electrode and follow the sec-ond-order mechanism.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48655226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.33961/jecst.2022.00423
L. Sathishkumar, Vetrivel Dhanapal, S. Ravi, R. Saratha, N. Sugumaran
Solar energy harvesting is practiced by various nations for the purpose of energy security and environment preservation in order to reduce overdependence on oil. Converting solar energy into electrical energy through Photovoltaic (PV) module can take place either in on-grid or off-grid applications. In recent time Lithium battery is exhibiting its presence in on-grid applications but its role in off-grid application is rarely discussed in the literature. The preliminary capacity and Peukert’s study indicated that the battery quality is good and can be subjected for life cycle test. The capacity of the battery was 10.82 Ah at 1 A discharge current and the slope of 1.0117 in the Peukert’s study indicated the reaction is very fast and inde-pendent on rate of discharge. In this study Lithium Iron Phosphate battery (LFP) after initial characterization was subjected to life cycle test which is specific to solar off-grid application as defined in IEC standard. The battery has delivered just 6 endurance units at room temperature before its capacity reached 75% of rated value. The low life of LFP battery in off-grid application is discussed based on State of Charge (SOC) operating window. The battery was operated both in high and low SOC’s in off-grid application and both are detrimental to life of lithium battery. High SOC operation resulted in cell-to-cell variation and low SOC operation resulted in lithium plating on negative electrode. It is suggested that to make it more suitable for off-grid applications the battery by default has to be overdesigned by nearly 40% of its rated capacity.
{"title":"Compatibility of Lithium ion Phosphate Battery in Solar off Grid Application","authors":"L. Sathishkumar, Vetrivel Dhanapal, S. Ravi, R. Saratha, N. Sugumaran","doi":"10.33961/jecst.2022.00423","DOIUrl":"https://doi.org/10.33961/jecst.2022.00423","url":null,"abstract":"Solar energy harvesting is practiced by various nations for the purpose of energy security and environment preservation in order to reduce overdependence on oil. Converting solar energy into electrical energy through Photovoltaic (PV) module can take place either in on-grid or off-grid applications. In recent time Lithium battery is exhibiting its presence in on-grid applications but its role in off-grid application is rarely discussed in the literature. The preliminary capacity and Peukert’s study indicated that the battery quality is good and can be subjected for life cycle test. The capacity of the battery was 10.82 Ah at 1 A discharge current and the slope of 1.0117 in the Peukert’s study indicated the reaction is very fast and inde-pendent on rate of discharge. In this study Lithium Iron Phosphate battery (LFP) after initial characterization was subjected to life cycle test which is specific to solar off-grid application as defined in IEC standard. The battery has delivered just 6 endurance units at room temperature before its capacity reached 75% of rated value. The low life of LFP battery in off-grid application is discussed based on State of Charge (SOC) operating window. The battery was operated both in high and low SOC’s in off-grid application and both are detrimental to life of lithium battery. High SOC operation resulted in cell-to-cell variation and low SOC operation resulted in lithium plating on negative electrode. It is suggested that to make it more suitable for off-grid applications the battery by default has to be overdesigned by nearly 40% of its rated capacity.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46247645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.33961/jecst.2022.00178
Jung-Hyeun Kim, Sang‐Mun Jung, Kyu-Su Kim, Sang-Hoon You, Byung-Jo Lee, Yong‐Tae Kim
With the emerging importance of catalysts for water electrolysis, developing efficient and inexpensive electrocatalysts for water electrolysis plays a vital role in renewable hydrogen energy technology. In this study, a 1nm thickness of TiC-sup-ported Ru catalyst for hydrogen evolution reaction (HER) has been successfully fabricated using an electron (E)-beam evaporator and thermal decomposition of gaseous CH 4 in a furnace. The prepared Ru/TiC catalyst exhibited an outstanding performance for alkaline hydrogen evolution reaction with an overpotential of 55 mV at 10 mA cm -2 . Furthermore, we demonstrated that the outstanding HER performance of Ru/TiC was attributed to the high surface area of the support and the metal-support interaction.
{"title":"Highly Active Electrocatalyst based on Ultra-low Loading of Ruthenium Supported on Titanium Carbide for Alkaline Hydrogen Evolution Reaction","authors":"Jung-Hyeun Kim, Sang‐Mun Jung, Kyu-Su Kim, Sang-Hoon You, Byung-Jo Lee, Yong‐Tae Kim","doi":"10.33961/jecst.2022.00178","DOIUrl":"https://doi.org/10.33961/jecst.2022.00178","url":null,"abstract":"With the emerging importance of catalysts for water electrolysis, developing efficient and inexpensive electrocatalysts for water electrolysis plays a vital role in renewable hydrogen energy technology. In this study, a 1nm thickness of TiC-sup-ported Ru catalyst for hydrogen evolution reaction (HER) has been successfully fabricated using an electron (E)-beam evaporator and thermal decomposition of gaseous CH 4 in a furnace. The prepared Ru/TiC catalyst exhibited an outstanding performance for alkaline hydrogen evolution reaction with an overpotential of 55 mV at 10 mA cm -2 . Furthermore, we demonstrated that the outstanding HER performance of Ru/TiC was attributed to the high surface area of the support and the metal-support interaction.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42805459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-23DOI: 10.33961/jecst.2022.00248
A. Bobyl, Sangsoo Nam, J. Song, Alexander Ivanishchev, A. Ushakov
For cuboid and ellipsoid crystallites of LiFePO 4 powders, by X-ray diffraction (XRD) and microscopic (TEM) studies, it is possible to determine the anisotropic parameters of the crystallite size distribution functions. These parameters were used to describe the cathode rate capability within the model of averaging the diffusion coefficient D over the length of the crystallite columns along the [010] direction. A LiFePO 4 powder was chosen for testing the developed model, consisting of big cuboid and small ellipsoid crystallites (close to them). When analyzing the parts of big and small rate сapabilities, the fitting values D = 2.1 and 0.3 nm 2 /s were obtained for cuboids and ellipsoids, respectively. When analyzing the results of cyclic voltammetry using the Randles-Sevcik equation and the total area of projections of electrode crystallites on their (010) plane, slightly different values were obtained, D = 0.9 ± 0.15 and 0.5 ± 0.15 nm 2 /s, respectively. We believe that these inconsistencies can be considered quite acceptable, since both methods of determining D have obvious sources of error. However, the developed method has a clearly lower systematic error due to the ability to actually take into account the shape and statistics of crystallites, and it is also useful for improving the accuracy of the Randles-Sevcik equation. It has also been demonstrated that the shape engineering of crystallites, among other tasks, can increase the cathode capacity by 15% by increasing their size correlation coefficients.
{"title":"Rate Capability of LiFePO4 Cathodes and the Shape Engineering of Their Anisotropic Crystallites","authors":"A. Bobyl, Sangsoo Nam, J. Song, Alexander Ivanishchev, A. Ushakov","doi":"10.33961/jecst.2022.00248","DOIUrl":"https://doi.org/10.33961/jecst.2022.00248","url":null,"abstract":"For cuboid and ellipsoid crystallites of LiFePO 4 powders, by X-ray diffraction (XRD) and microscopic (TEM) studies, it is possible to determine the anisotropic parameters of the crystallite size distribution functions. These parameters were used to describe the cathode rate capability within the model of averaging the diffusion coefficient D over the length of the crystallite columns along the [010] direction. A LiFePO 4 powder was chosen for testing the developed model, consisting of big cuboid and small ellipsoid crystallites (close to them). When analyzing the parts of big and small rate сapabilities, the fitting values D = 2.1 and 0.3 nm 2 /s were obtained for cuboids and ellipsoids, respectively. When analyzing the results of cyclic voltammetry using the Randles-Sevcik equation and the total area of projections of electrode crystallites on their (010) plane, slightly different values were obtained, D = 0.9 ± 0.15 and 0.5 ± 0.15 nm 2 /s, respectively. We believe that these inconsistencies can be considered quite acceptable, since both methods of determining D have obvious sources of error. However, the developed method has a clearly lower systematic error due to the ability to actually take into account the shape and statistics of crystallites, and it is also useful for improving the accuracy of the Randles-Sevcik equation. It has also been demonstrated that the shape engineering of crystallites, among other tasks, can increase the cathode capacity by 15% by increasing their size correlation coefficients.","PeriodicalId":15542,"journal":{"name":"Journal of electrochemical science and technology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42480547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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