Pub Date : 2024-10-02DOI: 10.1016/j.jallcom.2024.176857
Guodong Xu, Jiawei Shi, Changyuan Bao, Yuxin Liu, Yuxiang Zuo, Youzhen Dong, Bing Huang, Li Zhang, Jing Li, Weiwei Cai
Aiming to boosting the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) efficiency on the cost-effective transition metal catalysts, an in-situ mass transfer channel construction strategy is proposed for the carbon encapsulated Fe catalyst synthesis. By using Zn as sacrificial porogen and controlling the pyrolysis temperature during the catalyst synthesis, space left in the porous N-C encapsulated Fe (ZnFe-NC) catalyst due to the Zn evaporated can act as oxygen/water transfer channel for effective triple-phase boundary construction. Therefore, overpotential to deliver 10 mA cm-2 OER is low to 295 mV while half-slope potential of ORR is high to 0.88 V vs. RHE. Zinc-air battery using ZnFe-NC as the bi-functional oxygen catalyst exhibits both significantly improved power density and stability compared with that with the Pt/C-IrO2 catalysts, indicating the great application potential of the ZnFe-NC catalyst with in-situ constructed mass transfer channels.
{"title":"In-situ mass transfer channel construction in carbon encapsulated Fe catalyst for boosted bi-functional oxygen reactions","authors":"Guodong Xu, Jiawei Shi, Changyuan Bao, Yuxin Liu, Yuxiang Zuo, Youzhen Dong, Bing Huang, Li Zhang, Jing Li, Weiwei Cai","doi":"10.1016/j.jallcom.2024.176857","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176857","url":null,"abstract":"Aiming to boosting the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) efficiency on the cost-effective transition metal catalysts, an in-situ mass transfer channel construction strategy is proposed for the carbon encapsulated Fe catalyst synthesis. By using Zn as sacrificial porogen and controlling the pyrolysis temperature during the catalyst synthesis, space left in the porous N-C encapsulated Fe (ZnFe-NC) catalyst due to the Zn evaporated can act as oxygen/water transfer channel for effective triple-phase boundary construction. Therefore, overpotential to deliver 10<!-- --> <!-- -->mA<!-- --> <!-- -->cm<sup>-2</sup> OER is low to 295<!-- --> <!-- -->mV while half-slope potential of ORR is high to 0.88<!-- --> <!-- -->V vs. RHE. Zinc-air battery using ZnFe-NC as the bi-functional oxygen catalyst exhibits both significantly improved power density and stability compared with that with the Pt/C-IrO<sub>2</sub> catalysts, indicating the great application potential of the ZnFe-NC catalyst with in-situ constructed mass transfer channels.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176865
Saad Ali, Mohsin Ali Marwat, Muhammad Fawad Khan, Ahtisham Anjum, Muhammad Humayun, Mohamed Bououdina, Muhammad Bilal Hanif
The development of supercapacitor technology has been hindered by limitations in achieving both high power density and long cycle stability. Layered double hydroxides (LDHs) have emerged as promising candidates to address these challenges. In this study, we synthesized three distinct electrodes: NiCoMn LDH (LDH), Ag-citrate nanoparticles (Ag NPs), and a composite of Ag-citrate/NiCoMn LDH (Ag NPs/LDH), to explore their electrochemical performance. The structural and morphological characteristics of the synthesized materials were confirmed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Among the materials, the Ag NPs/LDH composite exhibited superior electrochemical properties, with distinct anodic and cathodic peaks of higher current intensity and an expanded integrated area in the current-voltage curve. Additionally, impedance analysis revealed the lowest charge transfer resistance, indicating efficient charging and discharging processes. In addition, the Ag-NPs/NiCoMn composite exhibited a remarkable aerial-specific capacitance of 2764 mF.cm−2 at 5 mA cm-2 in a three-electrode configuration. Furthermore, in an Asymmetric supercapacitor (ASC) device configuration of AgNPs/LDH as a working electrode and Activated carbon as a working electrode (shorthand form AgNPs/LDH ||AC ASC), a specific capacitance of 1850 mF.cm-2 at 5 mA.cm-2 was achieved. Encouragingly, the AgNPs/LDH||AC ASC device exhibited an energy density of 0.593 mWhcm-2 at a power density of 10 mW.cm-2, maintaining a 0.175 mWhcm-2 at a high-power density of 90 mWcm-2, while retaining 102% of its capacitance after 4000 charging and discharging cycles. Overall, the AgNPs/LDH electrode material demonstrates significant potential for advancement in supercapacitor technology.
{"title":"Ag NPs-modified NiCoMn Layered Double Hydroxides Electrodes for High-Performance Asymmetric Supercapacitors","authors":"Saad Ali, Mohsin Ali Marwat, Muhammad Fawad Khan, Ahtisham Anjum, Muhammad Humayun, Mohamed Bououdina, Muhammad Bilal Hanif","doi":"10.1016/j.jallcom.2024.176865","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176865","url":null,"abstract":"The development of supercapacitor technology has been hindered by limitations in achieving both high power density and long cycle stability. Layered double hydroxides (LDHs) have emerged as promising candidates to address these challenges. In this study, we synthesized three distinct electrodes: NiCoMn LDH (LDH), Ag-citrate nanoparticles (Ag NPs), and a composite of Ag-citrate/NiCoMn LDH (Ag NPs/LDH), to explore their electrochemical performance. The structural and morphological characteristics of the synthesized materials were confirmed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Among the materials, the Ag NPs/LDH composite exhibited superior electrochemical properties, with distinct anodic and cathodic peaks of higher current intensity and an expanded integrated area in the current-voltage curve. Additionally, impedance analysis revealed the lowest charge transfer resistance, indicating efficient charging and discharging processes. In addition, the Ag-NPs/NiCoMn composite exhibited a remarkable aerial-specific capacitance of 2764 mF.cm<sup>−2</sup> at 5<!-- --> <!-- -->mA<!-- --> <!-- -->cm<sup>-2</sup> in a three-electrode configuration. Furthermore, in an Asymmetric supercapacitor (ASC) device configuration of AgNPs/LDH as a working electrode and Activated carbon as a working electrode (shorthand form AgNPs/LDH ||AC ASC), a specific capacitance of 1850 mF.cm<sup>-2</sup> at 5<!-- --> <!-- -->mA.cm<sup>-2</sup> was achieved. Encouragingly, the AgNPs/LDH||AC ASC device exhibited an energy density of 0.593 mWhcm<sup>-2</sup> at a power density of 10<!-- --> <!-- -->mW.cm<sup>-2</sup>, maintaining a 0.175 mWhcm<sup>-2</sup> at a high-power density of 90 mWcm<sup>-2</sup>, while retaining 102% of its capacitance after 4000 charging and discharging cycles. Overall, the AgNPs/LDH electrode material demonstrates significant potential for advancement in supercapacitor technology.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176835
Kue-Ho Kim, Hyo-Jin Ahn
This paper describes the development of a highly flexible self-supporting cathode incorporating a network of entangled carbon nanofibers (CNFs) and well-dispersed sulfur-doped lithium iron phosphate (SLFP) particles. Through a spin-on-dopant process, sulfur atoms were successfully incorporated into both the surface carbon layer and inner LFP particles. The resulting S-doped carbon@LFP (SLFP-CNF) flexible electrode featured a unique hybrid composite architecture in which the interconnecting CNF framework considerably enhanced both the physical and electrochemical properties. Notably, the SLFP-CNF electrode maintained its structural integrity even after 5,000 flexibility cycles, demonstrating robust mechanical stability. The electrode exhibited a high ionic diffusion rate of 9.14 × 10–13 cm²/s, which is attributed to the expanded lattice constant of the S-doped LFP particles, which facilitates favorable Li-ion pathways. This contributes to a high specific capacity of 135.82 mAh/g and superior rate performance of 74.16 mAh/g after 1,500 cycles (92.4% retention rate) at a current density of 2,000 mA/g. This enhanced performance is further supported by the conductive S-doped carbon layer, which enables rapid electron transport and ensures excellent cyclability. These results indicate that the SLFP-CNF flexible cathode is a promising candidate for next-generation flexible lithium-ion batteries.
本文介绍了一种高柔性自支撑阴极的开发过程，该阴极包含纠缠在一起的碳纳米纤维（CNF）网络和分散良好的掺硫磷酸铁锂（SLFP）颗粒。通过自旋掺杂工艺，硫原子被成功地掺入到表面碳层和内部磷酸铁锂颗粒中。由此产生的 S 掺杂碳@磷酸铁锂（SLFP-CNF）柔性电极具有独特的混合复合结构，其中相互连接的 CNF 框架大大提高了物理和电化学性能。值得注意的是，SLFP-CNF 电极在经过 5,000 次柔性循环后仍能保持结构完整性，显示出强大的机械稳定性。该电极的离子扩散率高达 9.14 × 10-13 cm²/s，这归功于掺杂 S 的 LFP 粒子的晶格常数扩大，从而促进了有利的锂离子通路。因此，在电流密度为 2,000 mA/g 时，经过 1,500 次循环后，比容量达到 135.82 mAh/g，速率性能达到 74.16 mAh/g（保持率为 92.4%）。掺杂 S 的导电碳层可实现快速电子传输并确保出色的循环性，从而进一步支持了性能的提升。这些结果表明，SLFP-CNF 柔性阴极是下一代柔性锂离子电池的理想候选材料。
{"title":"Entangled S-doped LiFePO4 with carbon network for self-supporting cathode of flexible energy storage devices","authors":"Kue-Ho Kim, Hyo-Jin Ahn","doi":"10.1016/j.jallcom.2024.176835","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176835","url":null,"abstract":"This paper describes the development of a highly flexible self-supporting cathode incorporating a network of entangled carbon nanofibers (CNFs) and well-dispersed sulfur-doped lithium iron phosphate (SLFP) particles. Through a spin-on-dopant process, sulfur atoms were successfully incorporated into both the surface carbon layer and inner LFP particles. The resulting S-doped carbon@LFP (SLFP-CNF) flexible electrode featured a unique hybrid composite architecture in which the interconnecting CNF framework considerably enhanced both the physical and electrochemical properties. Notably, the SLFP-CNF electrode maintained its structural integrity even after 5,000 flexibility cycles, demonstrating robust mechanical stability. The electrode exhibited a high ionic diffusion rate of 9.14 × 10<sup>–13</sup> cm²/s, which is attributed to the expanded lattice constant of the S-doped LFP particles, which facilitates favorable Li-ion pathways. This contributes to a high specific capacity of 135.82<!-- --> <!-- -->mAh/g and superior rate performance of 74.16<!-- --> <!-- -->mAh/g after 1,500 cycles (92.4% retention rate) at a current density of 2,000<!-- --> <!-- -->mA/g. This enhanced performance is further supported by the conductive S-doped carbon layer, which enables rapid electron transport and ensures excellent cyclability. These results indicate that the SLFP-CNF flexible cathode is a promising candidate for next-generation flexible lithium-ion batteries.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176844
Keqi Chen, Zengmou Li, Keyu Zhang, Longbin Dai, Xiang Lin, Xiaoyue Shi, Shaoze Zhang, Bin Yang, Yaochun Yao
Iron oxalate is one of the highly potential anode materials for lithium-ion batteries, but its widespread application is limited by slow electron transfer rate and sluggish electrochemical reactions. Herein, iron oxalate/amorphous carbon microspheres (FeC2O4/PCC) composite with uniformly mixed crystalline phase for more stable active sites and three-dimensional conductive network, was synthesized via the in-situ self-polymerization, carbonization of β-cyclodextrin and recrystallization technique under solvothermal condition. The self-aggregation progress and kinetics of recrystallization accelerate the crystalline phase transformation of iron oxalate and the morphology reconstruction of micron-grade polygonal prism particles. Based on the fast electron migration facilitated by three-dimensional conductive network of PCC and exceptionally stable structure and Li+ diffusion channels endowed by strengthening effect of recrystallization, FeC2O4/PCC-15% exhibits long cycling life and outstanding ability for high-rate lithium storage: the specific capacities of 1231.50 and 1128.75 mAh g-1 after 500 cycles at current densities of 3 and 5 A g-1, with capacity retention rates of 90.79% and 81.08%, respectively. Furthermore, according to electrochemical capacity contribution analysis, PCC also can remarkably enhance the reversible lithium storage ability of interfacial capacitive effects and conversion reaction even under high current density. This work provides a new modification pathway for the application of transition metal oxalate systems in fast charging field.
草酸铁是极具潜力的锂离子电池负极材料之一，但其广泛应用受到电子转移速度慢和电化学反应迟缓的限制。本文通过原位自聚合、β-环糊精碳化和溶热条件下重结晶技术合成了草酸铁/无定形碳微球（FeC2O4/PCC）复合材料，其结晶相混合均匀，具有更稳定的活性位点和三维导电网络。自聚过程和重结晶动力学加速了草酸铁的晶相转变和微米级多棱柱颗粒的形貌重构。基于 PCC 三维导电网络促进的快速电子迁移，以及重结晶强化效应赋予的异常稳定的结构和 Li+ 扩散通道，FeC2O4/PCC-15% 显示出较长的循环寿命和出色的高倍率锂存储能力：在电流密度为 3 A 和 5 A g-1 的条件下，循环 500 次后的比容量分别为 1231.50 和 1128.75 mAh g-1，容量保持率分别为 90.79% 和 81.08%。此外，根据电化学容量贡献分析，即使在高电流密度下，PCC 也能显著增强界面电容效应和转化反应的可逆储锂能力。这项工作为过渡金属草酸盐体系在快速充电领域的应用提供了一条新的改性途径。
{"title":"Coordinate regulation of amorphous carbon microspheres and crystal structure of iron oxalate for high rate lithium storage ability","authors":"Keqi Chen, Zengmou Li, Keyu Zhang, Longbin Dai, Xiang Lin, Xiaoyue Shi, Shaoze Zhang, Bin Yang, Yaochun Yao","doi":"10.1016/j.jallcom.2024.176844","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176844","url":null,"abstract":"Iron oxalate is one of the highly potential anode materials for lithium-ion batteries, but its widespread application is limited by slow electron transfer rate and sluggish electrochemical reactions. Herein, iron oxalate/amorphous carbon microspheres (FeC<sub>2</sub>O<sub>4</sub>/PCC) composite with uniformly mixed crystalline phase for more stable active sites and three-dimensional conductive network, was synthesized via the in-situ self-polymerization, carbonization of β-cyclodextrin and recrystallization technique under solvothermal condition. The self-aggregation progress and kinetics of recrystallization accelerate the crystalline phase transformation of iron oxalate and the morphology reconstruction of micron-grade polygonal prism particles. Based on the fast electron migration facilitated by three-dimensional conductive network of PCC and exceptionally stable structure and Li<sup>+</sup> diffusion channels endowed by strengthening effect of recrystallization, FeC<sub>2</sub>O<sub>4</sub>/PCC-15% exhibits long cycling life and outstanding ability for high-rate lithium storage: the specific capacities of 1231.50 and 1128.75 mAh g<sup>-1</sup> after 500 cycles at current densities of 3 and 5<!-- --> <!-- -->A<!-- --> <!-- -->g<sup>-1</sup>, with capacity retention rates of 90.79% and 81.08%, respectively. Furthermore, according to electrochemical capacity contribution analysis, PCC also can remarkably enhance the reversible lithium storage ability of interfacial capacitive effects and conversion reaction even under high current density. This work provides a new modification pathway for the application of transition metal oxalate systems in fast charging field.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176860
Jie Zhu, Lingling Pan, Zhuoming Liu, Le-hua Liu, Zhi Li, Xinqiang Song, Keli Zeng, Chao Yang
Enhancing the strengths of most constant-expansion alloys, including Kovar alloys, typically results in reduced plasticities and increased coefficients of thermal expansion (CTEs). In this study, we systematically investigated the effects of carbon on the microstructure, mechanical properties, and CTE of a 4J29 Kovar alloy prepared via metal injection molding (MIM). When the carbon content was in the appropriate range, the strength and plasticity could be improved without compromising the CTE. MIM samples prepared by adding 1000 ppm graphite and oxalic acid for degreasing exhibited increases of 28.2% and 17.3% in tensile strength and elongation, respectively, compared to those of samples with low carbon contents of 46 ppm. The average CTE remained stable at 4.92 × 10⁻⁶ ℃–1 (25–400 ℃). The reduced number of pores at the grain boundaries was the main cause of the improvement in plasticity. The low CTE is attributed to the combined effect of the grain boundary volume fraction and porosity. This study provides significant theoretical and practical guidance for use in producing high-performance 4J29 Kovar alloys that may be used in complex components with constant-expansion properties.
{"title":"Enhancing the strength and plasticity of Kovar alloy without sacrificing thermal expansion properties","authors":"Jie Zhu, Lingling Pan, Zhuoming Liu, Le-hua Liu, Zhi Li, Xinqiang Song, Keli Zeng, Chao Yang","doi":"10.1016/j.jallcom.2024.176860","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176860","url":null,"abstract":"Enhancing the strengths of most constant-expansion alloys, including Kovar alloys, typically results in reduced plasticities and increased coefficients of thermal expansion (CTEs). In this study, we systematically investigated the effects of carbon on the microstructure, mechanical properties, and CTE of a 4J29 Kovar alloy prepared via metal injection molding (MIM). When the carbon content was in the appropriate range, the strength and plasticity could be improved without compromising the CTE. MIM samples prepared by adding 1000 ppm graphite and oxalic acid for degreasing exhibited increases of 28.2% and 17.3% in tensile strength and elongation, respectively, compared to those of samples with low carbon contents of 46 ppm. The average CTE remained stable at 4.92 × 10⁻⁶ ℃<sup>–1</sup> (25–400 ℃). The reduced number of pores at the grain boundaries was the main cause of the improvement in plasticity. The low CTE is attributed to the combined effect of the grain boundary volume fraction and porosity. This study provides significant theoretical and practical guidance for use in producing high-performance 4J29 Kovar alloys that may be used in complex components with constant-expansion properties.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176863
Tien Le, Yeonkyu Lee, Dzung T. Tran, Woo Seok Choi, Won Nam Kang, Jinyoung Yun, Jeehoon Kim, Jaegu Song, Yoonseok Han, Tuson Park, Duc H. Tran, Soon-Gil Jung, Jungseek Hwang
We investigated the superconducting (SC) properties of Ta–Nb–Hf–Zr–Ti high-entropy alloy (HEA) thin films with 0.5% weight C additives. The C additives stabilize the structural properties and enhance the SC critical properties, including μ0Hc2 (13.45 T) and Tc (7.5 K). The reflectance of the C-added HEA film is enhanced in the low-energy region, resulting in a higher optical conductivity, which is consistent with the lower electrical resistivity. In addition, we observed SC vortices in the C-added HEA film using magnetic force microscopy. The magnetic penetration depths (λ) of the pure HEA and C-added HEA films were estimated from their Meissner force curves by comparing them with those of a reference Nb film. At 4.2 K, the λ of the C-added film is 360 nm, shorter than that of the pure HEA film (560 nm), indicating stronger superconductivity against an applied magnetic field.
我们研究了添加 0.5% 重量级 C 添加剂的 Ta-Nb-Hf-Zr-Ti 高熵合金 (HEA) 薄膜的超导 (SC) 特性。C添加剂稳定了薄膜的结构特性，并增强了其超导临界特性，包括μ0Hc2（13.45 T）和Tc（7.5 K）。添加了 C 的 HEA 薄膜在低能区的反射率得到了增强，从而产生了更高的光导率，这与较低的电阻率是一致的。此外，我们还利用磁力显微镜在添加了 C 的 HEA 薄膜中观察到了 SC 涡流。通过将纯 HEA 薄膜和添加了 C 的 HEA 薄膜的迈斯纳力曲线与参考 Nb 薄膜的迈斯纳力曲线进行比较，估算出了它们的磁穿透深度 (λ)。在 4.2 K 时，添加了 C 的薄膜的 λ 为 360 nm，比纯 HEA 薄膜的 λ（560 nm）短，这表明它在外加磁场下具有更强的超导性。
{"title":"Effect of C additives with 0.5% in weight on structural, optical and superconducting properties of Ta–Nb–Hf–Zr–Ti high entropy alloy films","authors":"Tien Le, Yeonkyu Lee, Dzung T. Tran, Woo Seok Choi, Won Nam Kang, Jinyoung Yun, Jeehoon Kim, Jaegu Song, Yoonseok Han, Tuson Park, Duc H. Tran, Soon-Gil Jung, Jungseek Hwang","doi":"10.1016/j.jallcom.2024.176863","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176863","url":null,"abstract":"We investigated the superconducting (SC) properties of Ta–Nb–Hf–Zr–Ti high-entropy alloy (HEA) thin films with 0.5% weight C additives. The C additives stabilize the structural properties and enhance the SC critical properties, including <em>μ</em><sub>0</sub><em>H</em><sub>c2</sub> (13.45<!-- --> <!-- -->T) and <em>T</em><sub><em>c</em></sub> (7.5<!-- --> <!-- -->K). The reflectance of the C-added HEA film is enhanced in the low-energy region, resulting in a higher optical conductivity, which is consistent with the lower electrical resistivity. In addition, we observed SC vortices in the C-added HEA film using magnetic force microscopy. The magnetic penetration depths (<em>λ</em>) of the pure HEA and C-added HEA films were estimated from their Meissner force curves by comparing them with those of a reference Nb film. At 4.2<!-- --> <!-- -->K, the <em>λ</em> of the C-added film is 360<!-- --> <!-- -->nm, shorter than that of the pure HEA film (560<!-- --> <!-- -->nm), indicating stronger superconductivity against an applied magnetic field.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176845
Zeqing Wang, Zhihua Liu, Ronglan Zhang
Lithium-rich manganese-based cathode materials are well-regarded for their high specific capacity and notable voltage thresholds, making them attractive for advanced energy storage applications. However, their widespread commercialization is hindered by challenges in cycle performance, including suboptimal initial Coulombic efficiency, inadequate cycle stability, and constrained rate capability. To address these issues, this paper introduces a novel modification strategy using Na₂S₂O₈ to chemically delithiate the surface of the materials. This modification strategy dramatically enhances the initial Coulombic efficiency. The results demonstrate that the initial Coulombic efficiency of the two pre-activated samples improved to 84.6% and 102.2%, respectively. At the same time, the Na₂S₂O₈-treated samples exhibit a higher maximum discharge capacity at a 0.2 C rate, reaching 211.1 mAh g⁻¹ and 201.3 mAh g⁻¹, which notably surpasses the untreated sample's capacity of 188.7 mAh g⁻¹. Additionally, the treated samples exhibit improved cycling and rate performance, with capacity retention of 81.2% and 63.5%, respectively. After 60 cycles, these figures continue to be superior to those of the untreated material, which stands at 57.3%. The results demonstrate that Na₂S₂O₈ treatment leads to the in situ formation of spinel phases on the material surface, thereby enhances the cycling stability and rate capability of the cathode material. Compared to traditional surface treatment methods, Na₂S₂O₈ solution treatment can induce more profound structural evolution without necessitating high-temperature calcination, thus reducing the demands on process conditions and equipment and offering greater process controllability. Moreover, this surface modification strategy paves the way for applying spinel coatings on other substrates with similar structures.
富锂锰基阴极材料因其高比容量和显著的电压阈值而备受关注，这使它们对先进的储能应用具有吸引力。然而，它们的广泛商业化却受到循环性能挑战的阻碍，包括初始库仑效率不理想、循环稳定性不足以及速率能力受限。为了解决这些问题，本文介绍了一种新型改性策略，即使用 Na₂S₂O₈ 对材料表面进行化学脱硫处理。这种改性策略大大提高了初始库仑效率。结果表明，两种预活化样品的初始库仑效率分别提高到 84.6% 和 102.2%。同时，Na₂S₂O₈处理过的样品在 0.2 C 速率下表现出更高的最大放电容量，分别达到 211.1 mAh g-¹ 和 201.3 mAh g-¹，明显超过未处理样品的 188.7 mAh g-¹。此外，经过处理的样品的循环和速率性能也有所提高，容量保持率分别为 81.2% 和 63.5%。在 60 个循环后，这些数据继续优于未处理材料的 57.3%。结果表明，Na₂S₂O₈处理可在材料表面原位形成尖晶石相，从而提高阴极材料的循环稳定性和速率能力。与传统的表面处理方法相比，Na₂S₂O₈溶液处理无需高温煅烧就能诱导更深层次的结构演变，从而降低了对工艺条件和设备的要求，提高了工艺的可控性。此外，这种表面改性策略还为在具有类似结构的其他基底上应用尖晶石涂层铺平了道路。
{"title":"Improving the electrochemical performance of lithium-rich manganese-based cathode materials by Na₂S₂O₈ surface treatment","authors":"Zeqing Wang, Zhihua Liu, Ronglan Zhang","doi":"10.1016/j.jallcom.2024.176845","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176845","url":null,"abstract":"Lithium-rich manganese-based cathode materials are well-regarded for their high specific capacity and notable voltage thresholds, making them attractive for advanced energy storage applications. However, their widespread commercialization is hindered by challenges in cycle performance, including suboptimal initial Coulombic efficiency, inadequate cycle stability, and constrained rate capability. To address these issues, this paper introduces a novel modification strategy using Na₂S₂O₈ to chemically delithiate the surface of the materials. This modification strategy dramatically enhances the initial Coulombic efficiency. The results demonstrate that the initial Coulombic efficiency of the two pre-activated samples improved to 84.6% and 102.2%, respectively. At the same time, the Na₂S₂O₈-treated samples exhibit a higher maximum discharge capacity at a 0.2<!-- --> <!-- -->C rate, reaching 211.1 mAh g⁻¹ and 201.3 mAh g⁻¹, which notably surpasses the untreated sample's capacity of 188.7 mAh g⁻¹. Additionally, the treated samples exhibit improved cycling and rate performance, with capacity retention of 81.2% and 63.5%, respectively. After 60 cycles, these figures continue to be superior to those of the untreated material, which stands at 57.3%. The results demonstrate that Na₂S₂O₈ treatment leads to the in situ formation of spinel phases on the material surface, thereby enhances the cycling stability and rate capability of the cathode material. Compared to traditional surface treatment methods, Na₂S₂O₈ solution treatment can induce more profound structural evolution without necessitating high-temperature calcination, thus reducing the demands on process conditions and equipment and offering greater process controllability. Moreover, this surface modification strategy paves the way for applying spinel coatings on other substrates with similar structures.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuel cells, as promising energy conversion devices, realize the direct conversion of hydrogen fuel chemical energy into electrical energy. The kinetics of cathodic oxygen reduction reaction (ORR) is slow and plays a decisive role in the output efficiency of fuel cells. Platinum catalysts have been commercialized, but their high cost, relatively low catalytic activity and poor cycling durability limit the development of fuel cells. The introduction of non-platinum components is an effective strategy to minimize the cost and maximize the activity. In this study, PtPdCu medium entropy alloy nanoparticle nanotubes (PtPdCu MEANPTs) that demonstrate high catalytic activity and long durability are presented. Combined with density functional theory calculations, the introduction of Pd and Cu modulates surface electronic structure and optimizes the oxygen adsorption energy, thus enhancing the catalytic activity. The 0D/1D hybrid structure exposes more surface sites and inhibits particle maturation. The atomic migration and rearrangement are emerged during the initial stage of potential cycling process, induing a palladium-rich outer layer and preventing the oxidation of platinum atoms. The best-performing Pt24Pd28Cu48 MEANPTs deliver the impressive ORR activity (1.42 A/mgPt at 0.9 V vs. RHE, which is 6.17 times that of commercial Pt/C) and durability (retaining 2.87 times the initial activity of benchmark catalyst after 30, 000 potential cycles). Theoretical calculations have confirmed the regulation of alloying on the surface oxygen affinity and revealed the true active sites on the catalyst surface. This work explores the research direction of platinum-based multi-element catalysts with low platinum content and high catalytic activity.
{"title":"Engineering medium-entropy alloy nanoparticle nanotubes for efficient oxygen reduction","authors":"Qian Liu, Haoran Kang, Yiou Liu, Xiaowei Zhang, Yisong Zhao, Ying Meng, Faming Gao","doi":"10.1016/j.jallcom.2024.176859","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176859","url":null,"abstract":"Fuel cells, as promising energy conversion devices, realize the direct conversion of hydrogen fuel chemical energy into electrical energy. The kinetics of cathodic oxygen reduction reaction (ORR) is slow and plays a decisive role in the output efficiency of fuel cells. Platinum catalysts have been commercialized, but their high cost, relatively low catalytic activity and poor cycling durability limit the development of fuel cells. The introduction of non-platinum components is an effective strategy to minimize the cost and maximize the activity. In this study, PtPdCu medium entropy alloy nanoparticle nanotubes (PtPdCu MEANPTs) that demonstrate high catalytic activity and long durability are presented. Combined with density functional theory calculations, the introduction of Pd and Cu modulates surface electronic structure and optimizes the oxygen adsorption energy, thus enhancing the catalytic activity. The 0D/1D hybrid structure exposes more surface sites and inhibits particle maturation. The atomic migration and rearrangement are emerged during the initial stage of potential cycling process, induing a palladium-rich outer layer and preventing the oxidation of platinum atoms. The best-performing Pt<sub>24</sub>Pd<sub>28</sub>Cu<sub>48</sub> MEANPTs deliver the impressive ORR activity (1.42<!-- --> <!-- -->A/mg<sub>Pt</sub> at 0.9<!-- --> <!-- -->V <em>vs</em>. RHE, which is 6.17 times that of commercial Pt/C) and durability (retaining 2.87 times the initial activity of benchmark catalyst after 30, 000 potential cycles). Theoretical calculations have confirmed the regulation of alloying on the surface oxygen affinity and revealed the true active sites on the catalyst surface. This work explores the research direction of platinum-based multi-element catalysts with low platinum content and high catalytic activity.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-10-02DOI: 10.1016/j.jallcom.2024.176799
Cheng Yang, Haifeng Yue, Haidi Yao, Fang Niu, Man Wang, Bingan Chen, Zhenhuan Lu, De Ning, Chunlei Yang, Wei Wu
Lithium metal anode of the highest theoretical specific capacity promises a high-energy-density of the built lithium metal batteries (LMBs). However, the attainable high-energy throughout its calendar life necessitates a suppressed irreversible lithium consumption by realizing a uniform nucleation and a dense growth of lithium on current collector. Herein, an improved lithium reversibility is demonstrated on a lithiophilic 3D copper foil. 3D Cu of abundant gullies created by a microwave-induced oxidative etching enables an instantaneous conformal sulfurization of the substrate in 5 s without exfoliation. The sulfurized surface (Cu@Cu2S) of improved affinity towards lithium and the 3D pattern of densified nucleation sites jointly promote a uniform lithium deposition. The synergistically regulated lithium nucleation/growth behavior significantly improves the cycling stability (up to 580 cycles) of the high-loading (up to 3.4 mAh cm−2) full cells and pouch cells. In form of anode-free pouch cell, the substantial deceases in both the thickness and areal density of the processed Cu foil further increase the energy density of such prototype by 19.3% in gravimetry and 6.7% in volumetry, reaching 446 Wh kg−1 and 1224 Wh L−1, respectively. This work proposes a scalable, straightforward and efficient strategy to realize the high-energy while enduring LMBs.
{"title":"Ultrafast growth of sulfurized 3D composite host for high−energy dendrite−free lithium metal batteries","authors":"Cheng Yang, Haifeng Yue, Haidi Yao, Fang Niu, Man Wang, Bingan Chen, Zhenhuan Lu, De Ning, Chunlei Yang, Wei Wu","doi":"10.1016/j.jallcom.2024.176799","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176799","url":null,"abstract":"Lithium metal anode of the highest theoretical specific capacity promises a high-energy-density of the built lithium metal batteries (LMBs). However, the attainable high-energy throughout its calendar life necessitates a suppressed irreversible lithium consumption by realizing a uniform nucleation and a dense growth of lithium on current collector. Herein, an improved lithium reversibility is demonstrated on a lithiophilic 3D copper foil. 3D Cu of abundant gullies created by a microwave-induced oxidative etching enables an instantaneous conformal sulfurization of the substrate in 5<!-- --> <!-- -->s without exfoliation. The sulfurized surface (Cu@Cu<sub>2</sub>S) of improved affinity towards lithium and the 3D pattern of densified nucleation sites jointly promote a uniform lithium deposition. The synergistically regulated lithium nucleation/growth behavior significantly improves the cycling stability (up to 580 cycles) of the high-loading (up to 3.4 mAh cm<sup>−2</sup>) full cells and pouch cells. In form of anode-free pouch cell, the substantial deceases in both the thickness and areal density of the processed Cu foil further increase the energy density of such prototype by 19.3% in gravimetry and 6.7% in volumetry, reaching 446<!-- --> <!-- -->Wh<!-- --> <!-- -->kg<sup>−1</sup> and 1224<!-- --> <!-- -->Wh<!-- --> <!-- -->L<sup>−1</sup>, respectively. This work proposes a scalable, straightforward and efficient strategy to realize the high-energy while enduring LMBs.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Co3O4 was synthesized using electrospinning method and different amounts of carbon quantum dots (CQDs) were subsequently doped into the Co3O4 matrix via grinding, resulting in Co3O4/CQDs composite materials with various ratios. Gas sensing tests revealed that the resulting composite Co3O4/CQDs sensors exhibited excellent performance at a low temperature of 50°C, with outstanding selectivity towards ammonia gas and rapid response and recovery characteristics. Specifically, response and recovery time for 50 ppm ammonia gas were 14 s and 164 s, respectively. The outcomes of the exhalation simulation test utilizing sensors composed of this material demonstrate that the sensor's response to simulated chronic kidney disease breath closely approximates that of pure biological samples (1.08), exceeding the average response value of healthy exhaled breath samples (1.0). This demonstrates the sensor's capability to differentiate between healthy individuals and chronic kidney disease patients despite significant water vapor and carbon dioxide interference. This study provides valuable insights for the development of more efficient ammonia sensors and their role in the early detection of chronic kidney disease.
{"title":"Co3O4/CQDs Composite for Selective Ammonia Detection in Exhaled Human Breath Analysis","authors":"Jiapeng Xu, Lijuan Fu, Chaoqiang Liu, Qingyu Liu, Wei Tang","doi":"10.1016/j.jallcom.2024.176831","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.176831","url":null,"abstract":"Co<sub>3</sub>O<sub>4</sub> was synthesized using electrospinning method and different amounts of carbon quantum dots (CQDs) were subsequently doped into the Co<sub>3</sub>O<sub>4</sub> matrix via grinding, resulting in Co<sub>3</sub>O<sub>4</sub>/CQDs composite materials with various ratios. Gas sensing tests revealed that the resulting composite Co<sub>3</sub>O<sub>4</sub>/CQDs sensors exhibited excellent performance at a low temperature of 50°C, with outstanding selectivity towards ammonia gas and rapid response and recovery characteristics. Specifically, response and recovery time for 50 ppm ammonia gas were 14<!-- --> <!-- -->s and 164<!-- --> <!-- -->s, respectively. The outcomes of the exhalation simulation test utilizing sensors composed of this material demonstrate that the sensor's response to simulated chronic kidney disease breath closely approximates that of pure biological samples (1.08), exceeding the average response value of healthy exhaled breath samples (1.0). This demonstrates the sensor's capability to differentiate between healthy individuals and chronic kidney disease patients despite significant water vapor and carbon dioxide interference. This study provides valuable insights for the development of more efficient ammonia sensors and their role in the early detection of chronic kidney disease.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":6.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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