Journal of Electroanalytical Chemistry最新文献_第4页

Enhanced electrocatalytic water splitting performance and stability of MnO₂ through Ru doping Ru掺杂提高了mno2的电催化裂解性能和稳定性

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-31 DOI: 10.1016/j.jelechem.2025.119778

Yong Luo , Feng Gao , Jie Zhang , Xiaoyan Zhang

The development of efficient and durable bifunctional electrocatalysts based on earth-abundant elements for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is critical for advancing sustainable hydrogen production. Herein, a facile one-step hydrothermal strategy was developed to synthesize Ru-doped α-MnO₂ nanoneedles grown on carbon paper (Ru_0.02MnO₂/CP) as a novel bifunctional electroccatalyst. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses revealed that Ru incorporation induces uniform lattice distortion in MnO₂, significantly increasing the density of oxygen vacancies and catalytically active Mn³⁺ sites. The structural modifications enhance the intrinsic electrochemical activity and structural stability of MnO₂ during HER/OER in alkaline media. The optimized Ru_0.02MnO₂/CP catalyst exhibited exceptional bifunctional performance, achieving low overpotentials of 107 mV (HER) and 261 mV (OER) at 10 mA cm⁻². Furthermore, stability testing under continuous operation reveals <6 % activity loss over 100 h at 10 mA cm⁻². Density functional theory (DFT) calculations revealed that Ru doping optimizes the adsorption/desorption energetics of reaction intermediates (*H for HER; *OH for OER), effectively lowering the kinetic barriers and overpotentials for both half-reactions. This work provides a rational strategy for designing high-performance and cost-effective bifunctional electrocatalyst, advancing their potential application in scalable water electrolysis for sustainable hydrogen production.

开发高效、耐用的基于地球丰度元素的析氢和析氧双功能电催化剂是推进可持续制氢的关键。本文提出了一种简单的一步水热策略来合成在碳纸上生长的ru掺杂α-MnO2纳米针（Ru0.02MnO2/CP）作为新型双功能电催化剂。透射电镜（TEM）和x射线衍射（XRD）分析表明，Ru的掺入导致MnO2中均匀的晶格畸变，显著增加了氧空位和催化活性Mn3+位点的密度。这些结构修饰提高了MnO2在碱性介质中HER/OER过程中的固有电化学活性和结构稳定性。优化后的Ru0.02MnO2/CP催化剂表现出优异的双功能性能，在10 mA cm−2下可实现107 mV （HER）和261 mV （OER）的低过电位。此外，在连续操作下的稳定性测试显示，在10 mA cm - 2下，100小时的活度损失为<； 6%。密度泛函理论（DFT）计算表明，Ru掺杂优化了反应中间体的吸附/解吸能量（HER为*H， OER为*OH），有效降低了半反应的动力学势垒和过电位。本研究为设计高性能、低成本的双功能电催化剂提供了合理的策略，促进了双功能电催化剂在大规模水电解可持续制氢中的潜在应用。

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引用次数: 0

Melanin-driven heteroatom incorporation in bird feather-derived activated carbon for high-performance supercapacitors 用于高性能超级电容器的鸟羽毛衍生活性炭中黑色素驱动的杂原子掺入

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119777

Kapil Dev Verma , Kamal K. Kar

In the rapidly advancing field of energy storage, the integration of sustainable materials with superior performance metrics has become essential. Bird feathers, an abundant byproduct of poultry and domestic waste, are largely underutilised and contribute to environmental concerns due to their resistance to degradation. Composed of β-keratin and melanin pigments, feathers offer a unique opportunity for sustainable conversion into value-added carbon materials. In this study, feathers of three distinct colours, black (crow), grey (peacock), and white (duck), were employed as precursors for activated carbon electrodes to evaluate the role of melanin concentration on heteroatom incorporation and electrochemical performance. The prepared activated carbons demonstrated a strong correlation between pigmentation and specific capacitance, attributed to melanin-induced nitrogen and oxygen functionalities. The symmetric supercapacitors delivered specific capacitances of 361 ± 10 F g⁻¹ for crow feather-derived carbon, 384 ± 2.5 F g⁻¹ for peacock feather-derived carbon, and 341 ± 9 F g⁻¹ for duck feather-derived carbon at 1 A g⁻¹ in 6 M KOH electrolyte. These findings establish bird feathers as a sustainable carbon precursor and highlight the critical role of melanin content in enhancing electrochemical charge storage, thereby offering a pathway for environmentally benign and high-performance supercapacitor electrode materials.

在快速发展的能源存储领域，具有卓越性能指标的可持续材料的集成已成为必不可少的。鸟类羽毛是家禽和家庭废物的大量副产品，但由于它们不易降解，因此在很大程度上未得到充分利用，并引起环境问题。羽毛由β-角蛋白和黑色素组成，为可持续转化为增值碳材料提供了独特的机会。本研究采用黑色（乌鸦）、灰色（孔雀）和白色（鸭子）三种不同颜色的羽毛作为活性炭电极的前驱体，以评估黑色素浓度对杂原子掺入和电化学性能的影响。所制备的活性炭在色素沉着和比电容之间表现出很强的相关性，这归因于黑色素诱导的氮和氧官能团。在6 M KOH电解液中，在1 A g−1条件下，乌鸦羽毛衍生碳的比电容为361±10 F g−1，孔雀羽毛衍生碳的比电容为384±2.5 F g−1，鸭羽毛衍生碳的比电容为341±9 F g−1。这些发现证实了鸟羽毛是一种可持续的碳前体，并强调了黑色素含量在增强电化学电荷存储方面的关键作用，从而为环保和高性能的超级电容器电极材料提供了途径。

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引用次数: 0

Design of polypyrrole-modified NiCo-LDH electrocatalysts for high-performance seawater electrolysis 聚吡咯改性NiCo-LDH高性能海水电解电催化剂的设计

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119759

Ziqi Wang , Xiaomei Wang , Zhihao Xia , Tian Tian , Yucai Li , Shiwei Song , Jian Wang , Fang Hu , Lihua Miao

Among numerous transition metal hydrogen evolution reaction catalysts, nickel-based catalysts have garnered significant attention for their relatively better electrocatalytic activity. The hydrothermal-electrodeposition method provides an effective route for preparing relatively better nickel-based catalysts. Building upon this, this study successfully synthesised NiCo-LDH@PPy. Under alkaline conditions, NiCo-LDH@PPy-100 exhibits a HER overpotential of 210.7 mV at 50 mA cm⁻² and a double-layer capacitance of 0.013 mF cm⁻². Following 28 h of constant current testing, XPS experiments revealed minimal changes in elemental composition, suggesting good stability of the sample under electrochemical conditions. To more accurately evaluate the practical application potential of the catalyst, when the electrolyte was switched to alkaline seawater, NiCo-LDH@PPy-100 exhibits HER and OER overpotentials of 223.7 mV and 270 mV at 50 mA cm⁻², respectively. The overall water splitting potential was 1.64 V at a current density of 10 mA cm⁻², and the catalyst demonstrated excellent electrochemical stability during 50 h of continuous testing, offering a viable alternative to precious metal catalysts for seawater splitting.

在众多的过渡金属析氢反应催化剂中，镍基催化剂因其相对较好的电催化活性而备受关注。水热电沉积法为制备性能相对较好的镍基催化剂提供了一条有效途径。在此基础上，本研究成功合成了NiCo-LDH@PPy。在碱性条件下，NiCo-LDH@PPy-100在50 mA cm−2时的HER过电位为210.7 mV，双层电容为0.013 mF cm−2。恒流测试28 h后，XPS实验显示样品元素组成变化很小，表明样品在电化学条件下具有良好的稳定性。为了更准确地评估催化剂的实际应用潜力，当电解质切换到碱性海水中时，NiCo-LDH@PPy-100在50 mA cm−2下的HER和OER过电位分别为223.7 mV和270 mV。在10 mA cm−2电流密度下，总水分解电位为1.64 V，在50 h的连续测试中表现出优异的电化学稳定性，为海水分解提供了一种可行的替代贵金属催化剂。

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引用次数: 0

Coconut shell-derived petaloid defect-rich carbon as profitable catalyst support for MoSe2 in electrocatalytic hydrogen production 椰壳衍生的花瓣状缺陷碳作为电催化制氢中MoSe2的有利催化剂载体

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119779

Kangming Wang , Baitong Niu , Shakeel Ahmed , Cheng Zheng , Dan Jiang , Zilin Shen , Yinghe Zhao , Dongping Zhang , Baodong Du , Rui Niu , Yong Chen

MoSe₂ is a potential non-noble metal catalyst for electrocatalytic hydrogen evolution reaction (HER) due to its intrinsic catalytic activity and excellent chemical stability. Inducing vertical align of MoSe₂ nanosheets on curved and rough supports have been proven to maximally expose active sites, and thereby improve its HER performance for practical use. Herein, a petaloid defect-rich coconut shell-based carbon (CBC) supports is developed, which not only significantly enhances the HER performance of MoSe₂, but also make full use of biowaste of coconut. It is revealed that CBC effectively regulates the vertical align of MoSe₂ nanosheet on its surface than commercial graphite nanosheets (CGN), and the MoC bonds formation further fastens the anchoring of MoSe₂ nanosheets. Consequently, the MoSe₂/CBC composite exhibits a low overpotential of 132 mV at 10 mA·cm⁻² in 0.5 M H₂SO₄ electrolyte. Remarkably, it also achieves an overpotential of only 984 mV at a high current density of 600 mA·cm⁻², which is superior to the commercial Pt/C catalyst. Moreover, density functional theory calculations theoretically explain the underlying reason why MoSe₂ nanosheets tend to vertically grow on defected carbon and elucidate the enhanced HER performance from the perspective of electron structure on the interface between MoSe₂ and carbon support.

MoSe2由于其固有的催化活性和优异的化学稳定性，是电催化析氢反应（HER）的潜在非贵金属催化剂。在弯曲和粗糙的支架上诱导MoSe2纳米片的垂直排列已被证明可以最大限度地暴露活性位点，从而提高其在实际应用中的HER性能。本文开发了一种富含花瓣状缺陷的椰壳碳（CBC）载体，该载体不仅显著提高了MoSe2的HER性能，而且充分利用了椰子的生物废弃物。结果表明，CBC比商用石墨纳米片（CGN）更有效地调节了MoSe2纳米片在其表面的垂直排列，MoC键的形成进一步加强了MoSe2纳米片的锚定。因此，在0.5 M H2SO4电解质中，MoSe2/CBC复合材料在10 mA·cm−2下具有低过电位132 mV。值得注意的是，在600 mA·cm−2的高电流密度下，该催化剂的过电位仅为984 mV，优于商用Pt/C催化剂。此外，密度泛函理论计算从理论上解释了MoSe2纳米片倾向于在缺陷碳上垂直生长的根本原因，并从MoSe2与碳载体界面上的电子结构角度阐明了HER性能的增强。

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引用次数: 0

Anion-engineered solid electrolyte interphase enables high reversible capacity of cobalt polyphthalocyanine organic electrode for Lithium-ion batteries 阴离子工程固体电解质间相使锂离子电池用聚酞菁钴有机电极具有高可逆容量

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119773

Zaoyan Yu, Yushuai Song, Zhensheng Guan, Wenruo Li, Luzheng Zhao, Jiancong Guo, Haoyuan Zhu, Zhongsheng Wen

Unstable solid electrolyte interface and sluggish kinetics due to the high solubility and low ionic/electronic conductivity are the main issues for organic materials applied in nonaqueous metal-ion batteries, despite their diversity, property tunability and environmental friendliness. Here, an anion engineering in solid organic materials of cobalt polyphthalocyanine (CoPPc) for lithium-ion storage is proposed and explored strategically to tailor the electrochemically forming process of the solid-state interface (SEI) films to resist the solubility of the organic active center. To achieve the target, Trioctylphosphine oxide (TOPO) was introduced into CoPPc. The results demonstrate that the incorporation of TOPO into CoPPc could dramatically influence the adsorption of PF₆⁻ groups on the surface of the CoPPc electrode, resulting in the formation of uniform and robust SEI films and the enhancement of the reversible capacity. The anion-engineered CoPPc electrode delivers a reversible capacity of 986.3 mAh g⁻¹ after 200 cycles at 200 mA g⁻¹ with an apparent capacity increment of 35.9 %. In addition, the anion-engineered CoPPc electrode maintained a high stability capacity of 690.8 mAh g⁻¹ after 1000 cycles at 1 A g⁻¹, showing exceptional rate capability and long-term cycling stability. Our theoretical simulations further demonstrate that the shortening of the CoN bond changes the electronic distribution in CoPPc and thus induces the preferential adsorption of PF₆⁻ groups. In addition, the weakening of the CoN bond energy strengthens the reversibility of the cobalt ions. This work provides a new anion-engineering strategy for developing organic electrode materials for LIBs with high-capacity and long-term cycling stability.

尽管有机材料具有多样性、性能可调性和环境友好性，但由于其高溶解度和低离子/电子电导率而导致的固体电解质界面不稳定和动力学缓慢是其应用于非水金属离子电池的主要问题。本文提出了一种用于锂离子存储的固体有机材料聚酞菁钴（CoPPc）的阴离子工程，并对其进行了战略性探索，以调整固态界面（SEI）薄膜的电化学形成过程，以抵抗有机活性中心的溶解度。为实现这一目标，将氧化三辛基膦（TOPO）引入到CoPPc中。结果表明，在CoPPc中掺入TOPO可以显著影响PF6−基团在CoPPc电极表面的吸附，从而形成均匀且坚固的SEI膜，增强了可逆容量。阴离子工程的CoPPc电极在200 mA g - 1下循环200次后可提供986.3 mAh g - 1的可逆容量，表观容量增加35.9%。此外，阴离子工程的CoPPc电极在1 a g−1下循环1000次后仍保持690.8 mAh g−1的高稳定容量，表现出优异的倍率能力和长期循环稳定性。我们的理论模拟进一步表明，CoN键的缩短改变了CoPPc中的电子分布，从而诱导了PF6−基团的优先吸附。此外，CoN键能的减弱增强了钴离子的可逆性。这项工作为开发具有高容量和长期循环稳定性的锂离子电池有机电极材料提供了一种新的阴离子工程策略。

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引用次数: 0

A voltammetric electronic tongue array for tea brewing assessment via multi-electrode electrocatalytic fingerprinting 多电极电催化指纹鉴定茶叶冲泡的伏安电子舌阵列

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119776

Wei-Li Shih, Lin-Chi Chen

Voltammetric electronic tongues (VETs) offer a promising method for on-site monitoring of the flavor and quality of beverages during their production to ensure the preservation of their natural and desirable flavor. To integrate the complementary sensing perspectives of distinct materials, we rationally selected poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and PEDOT:ClO₄, Prussian blue (PB), copper hexacyanoferrate (CuHCF), standard gold electrode, and glassy carbon electrode as the cross-sensitive sensing elements of the VET. Their responses to common antioxidant molecules—caffeic acid, chlorogenic acid, gallic acid, catechin, and epigallocatechin gallate—were systematically investigated to establish analyte-dependent electrochemical fingerprints. These electrodes were then applied to analyze undiluted commercial tea samples, where the voltammetric profiles correlated strongly with their antioxidant activity (R² ≈ 0.9). Furthermore, the system successfully distinguished teas brewed at different temperatures and enabled the derivation of an interpretable “cold brew index.” Overall, the proposed multi-electrode VET provides a rapid, low-cost, and integrable approach for assessing tea quality, and it holds great potential for extending to the quality evaluation of other beverages.

伏安电子舌（VETs）是一种很有前途的方法，可以在饮料生产过程中对其风味和质量进行现场监测，以确保饮料保持其天然和理想的风味。为了整合不同材料的互补传感视角，我们合理选择了聚（3,4-乙烯二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）和PEDOT:ClO4、普鲁士蓝（PB）、六氰高铁酸铜（CuHCF）、标准金电极和玻碳电极作为VET的交叉敏感传感元件。系统研究了它们对常见抗氧化分子——咖啡酸、绿原酸、没食子酸、儿茶素和表没食子儿茶素没食子酸的反应，建立了分析物依赖的电化学指纹图谱。这些电极随后被应用于分析未稀释的商业茶样品，其中伏安谱与其抗氧化活性密切相关（R2≈0.9）。此外，该系统成功地区分了在不同温度下冲泡的茶，并能够推导出可解释的“冷冲泡指数”。总之，所提出的多电极VET为茶叶质量评估提供了一种快速、低成本、可集成的方法，并具有推广到其他饮料质量评估的巨大潜力。

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引用次数: 0

Synergistic effects in MOF-derived ZnO/ZnV2O4 Heterostructures as high-performance cathodes for aqueous zinc-ion batteries mof衍生ZnO/ZnV2O4异质结构作为高性能锌离子电池阴极的协同效应

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119780

Guohua Chen , Jing Ning , Liying Wang , Qian Liu , Yuan Wang , Zhenzhu Cao , Yongfeng Zhang , Shaohua Luo

For grid-scale energy storage systems, aqueous zinc-ion rechargeable batteries (AZIRBs) offer attractive potential. Nevertheless, their practical implementation faces multiple obstacles poor Zn²⁺ migration speeds, inadequate electrode surface activity, and naturally low electrical conductivity have hindered the full exploitation of their potential. The Zn-BDC metal-organic framework (MOF) precursor was synthesized via a mechanochemical method, followed by high-temperature calcination to obtain ZnO/ZnV₂O₄ heterostructured composites. This material demonstrates multiple advantages through its unique structural design, with the introduction of Zn²⁺ inducing the formation of a nanosheet structure decorated with nanoparticles during calcination, the large specific surface area facilitating the penetration of electrolyte into the electrode interior during charge/discharge to enhance ion diffusion efficiency, and the interfacial electric field of the heterostructure also promoting charge separation and enhancing the kinetics of redox reactions. Which were evaluated as cathode materials for aqueous zinc-ion batteries. Electrochemical performance tests demonstrated that the ZnO/ZnV₂O₄ material, as a cathode for aqueous zinc-ion batteries (AZIBs), exhibits excellent electrochemical performance, including a high specific capacity (387.5 mAh g⁻¹ at 1 A g⁻¹), superior rate capability, and long cycle life (178.7 mAh g⁻¹ after 4000 cycles at 20 A g⁻¹). Through ex-situ XRD and XPS analyses, the reversible Zn²⁺ insertion/extraction mechanism was elucidated, confirming the material's high reversibility during charge/discharge processes.

对于电网规模的储能系统，锌离子可充电电池（azirb）具有诱人的潜力。然而，它们的实际应用面临着多种障碍：Zn2+迁移速度差、电极表面活性不足以及天然的低导电性阻碍了其潜力的充分开发。采用机械化学方法合成了Zn-BDC金属有机骨架（MOF）前驱体，然后通过高温煅烧得到ZnO/ZnV2O4异质结构复合材料。该材料通过其独特的结构设计显示出多种优势，在煅烧过程中引入Zn2+诱导形成带有纳米颗粒装饰的纳米片结构，在充放电过程中，大的比表面积有利于电解质渗透到电极内部，提高离子扩散效率。异质结构的界面电场也促进了电荷分离，增强了氧化还原反应的动力学。对其作为锌离子电池正极材料进行了评价。电化学性能测试表明，ZnO/ZnV2O4材料作为水锌离子电池（AZIBs）的正极材料，具有优异的电化学性能，包括高比容量（在1 a g−1下可达387.5 mAh g−1）、优越的倍率性能和长循环寿命（在20 a g−1下可循环4000次后达到178.7 mAh g−1）。通过非原位XRD和XPS分析，阐明了Zn2+的可逆插入/萃取机理，证实了材料在充放电过程中具有较高的可逆性。

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引用次数: 0

Wiring cells by conductive nanowires to enhance bidirectional electron transfer 用导电纳米线连接细胞以增强双向电子转移

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-30 DOI: 10.1016/j.jelechem.2025.119781

Le Tao , Bolei Chen , Maoyong Song , Guibin Jiang

Sluggish extracellular electron transfer (EET) efficiency severely restricts the output power density of microbial fuel cell (MFC) and consequently its practical applications. Currently, most research focuses on enhancing EET at the biotic-electrode interface, ignoring the fact that electricigens are 3D micron-scaled electrocatalysts and thus only part of their cell surfaces can achieve direct contact with the 2D surface of current collector. That is, the contact area between the 3D micron-scaled electrocatalyst and the 2D surface of conventional current collector is limited. Herein, to resolve that issue, conductive nanowires are synthesized after electricigens already reside on the 2D surface of current collector, electrically wiring up regions of bacterial surface that the conventional 2D plane of electrode cannot touch to the current collector, which creates more direct contact sites with both electricigens and electron shuttles to significantly accelerate bidirectional electron transfer via both DET and MET. Moreover, electricigens can vigorously propagate and regrow within PPy nanowires due to the hydrophilicity and the relatively high electronic conductivity of nanowires as well as enough space existing among nanowires. This work provides a new concept that microbial electrocatalysis is enhanced by increasing contact sites between the 3D microbial electrocatalyst and the 2D surface of current collector, apart from ameliorating interfacial electron transfer only and the MFC performance will be further improved in future when engineered electricigens with upregulated secretion level of flavins are used as microbial electrocatalysts in MFC.

细胞外电子转移效率低下严重制约了微生物燃料电池的输出功率密度，影响了其实际应用。目前，大多数研究都集中在生物电极界面的EET增强上，而忽略了电剂是三维微米尺度的电催化剂，因此只有部分电池表面可以与集流器的二维表面直接接触。即三维微米级电催化剂与传统集流器二维表面的接触面积有限。为了解决这一问题，在电流集热器的二维表面上已经存在了导电纳米线，将传统的二维电极平面无法接触的细菌表面区域与电流集热器电连接起来，这就创造了更多的与电流和电子穿梭体的直接接触点，从而显著加速了通过DET和MET的双向电子转移。此外，由于纳米线的亲水性和较高的电子导电性，以及纳米线之间存在足够的空间，电分子可以在PPy纳米线内迅速繁殖和再生。本研究提供了一个新的概念，即除了改善界面电子转移外，还可以通过增加三维微生物电催化剂与集流器二维表面之间的接触位点来增强微生物电催化作用，未来在MFC中使用上调黄素分泌水平的工程电剂作为微生物电催化剂将进一步提高MFC的性能。

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引用次数: 0

Equimolar bimetallic vanadium titanium based Prussian blue analogue as zero strain cathode for sodium ion batteries 钠离子电池零应变阴极等摩尔双金属钒钛基普鲁士蓝类似物

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-29 DOI: 10.1016/j.jelechem.2025.119775

Omama Javed , Rimsha Mehek , Ghulam Ali , Radhiyah Binti Abd Aziz

Prussian blue analogues (PBAs) are attractive cathode materials for sodium-ion batteries because of their open framework, rapid ion transport, and low-cost aqueous synthesis; however, electrochemical performance is often limited by defect/water chemistry and the associated structural instability during cycling. Here, we report an equimolar bimetallic titanium/vanadium PBA, Na₂Ti₀.₅V₀.₅[Fe(CN)₆], synthesized by a simple solution precipitation route and systematically compared with non-equimolar Ti/V analogues prepared under identical conditions. X-ray diffraction confirms a single-phase cubic framework (Fm3̅m). In non-aqueous Na half-cells (2.0–4.5 V vs. Na/Na⁺), Na₂Ti₀.₅V₀.₅[Fe(CN)₆] delivers an initial discharge capacity of 68.7 mAh g⁻¹ at 0.1C and retains 62.35 mAh g⁻¹ after 200 cycles (≈90.8 % retention) with near-unity Coulombic efficiency. Rate capability (0.1C → 10C → 1C) shows stable capacity at high rates and clear recovery on returning to lower current. Electroanalytical measurements indicate favorable kinetics: EIS reveals reduced charge-transfer resistance for the equimolar composition, and CV scan-rate analysis yields an apparent Na⁺ diffusion coefficient of 2.33 × 10⁻⁸ cm² s⁻¹. In situ XRD demonstrates single-phase Na⁺ (de)insertion with highly reversible lattice breathing; quantitative lattice-parameter tracking gives a maximum volumetric strain of ∼0.07 %, supporting a near-zero-strain mechanism. TGA confirms reduced water content for the equimolar material, consistent with its enhanced phase stability.

普鲁士蓝类似物（PBAs）因其开放的结构、快速的离子传输和低成本的水合成而成为钠离子电池极具吸引力的正极材料；然而，在循环过程中，电化学性能往往受到缺陷/水化学和相关结构不稳定性的限制。在这里，我们报告了一种等摩尔双金属钛/钒PBA， Na₂Ti 0 .₅V 0。₅[Fe（CN）₆]，采用简单的溶液沉淀法合成，并与相同条件下制备的非等摩尔Ti/V类似物进行系统比较。x射线衍射证实为单相立方骨架（Fm3 ~ m）。在非水钠半电池中（2.0-4.5 V vs. Na/Na+）， Na₂Ti 0 .₅V 0 .₅[Fe（CN）₆]在0.1C时提供68.7 mAh g - 1的初始放电容量，并在200次循环后保持62.35 mAh g - 1（≈90.8%保留率），具有接近统一的库仑效率。倍率能力（0.1C→10C→1C）在高倍率下表现出稳定的容量，在返回低电流时表现出明显的恢复。电分析测量表明了良好的动力学：EIS显示等摩尔成分的电荷转移阻力降低，CV扫描速率分析显示Na+的表观扩散系数为2.33 × 10−8 cm2 s−1。原位XRD显示单相Na+ (de)插入具有高度可逆的晶格呼吸；定量点阵参数跟踪给出的最大体积应变为~ 0.07%，支持接近零应变的机制。TGA证实等摩尔材料的含水量降低，与相稳定性增强相一致。

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引用次数: 0

Influence mechanism of ionomer and carbon on transient mass transfer and dynamic electrical performance of proton exchange membrane fuel cells 离子和碳对质子交换膜燃料电池瞬态传质和动态电性能的影响机理

IF 4.1 3区化学 Q1 CHEMISTRY, ANALYTICAL

Journal of Electroanalytical Chemistry

Pub Date : 2025-12-29 DOI: 10.1016/j.jelechem.2025.119766

Yi Tong Li, Hang Guo, Fang Ye, Hao Chen

The transient behavior of proton exchange membrane fuel cells in vehicles is highly significant for system stability and durability. Catalyst layers serve as the primary sites for electrochemical reactions. However, the influence mechanism of ionomer loading and carbon content in catalyst layers on transient electrical performance and mass transfer is still unknown. Therefore, the transient three-dimensional fuel cell model coupled with the catalyst layer agglomerate model is established in this work. The effects of ionomer and carbon contents on transient characteristics are analyzed in terms of oxygen transport, dissolved water transport, and the uniformity of dissolved water distribution. The comprehensive performance coefficient and non-uniformity coefficient are proposed to evaluate transient performance. Results demonstrate that a higher ionomer content increases the overshoot amplitude and the response time of the current density, however it decreases the surge of heterogeneity coefficient of dissolved water distribution. At an ionomer fraction of 0.3, the steady-state current density rises by 5.48 %, and the current density overshoot amplitude reduces by 16.61 % compared to the case at an ionomer fraction of 0.5. The influence of carbon content on steady-state electrical property is greater than that on transient overshoot amplitude. Additionally, the cell enters the stage dominated by oxygen concentration more slowly under high carbon loading. Oxygen replenishment in the downstream region is critical because the reduction of local current density and oxygen content after load change mainly occurs in the downstream area. This study provides an effective strategy for optimizing the catalyst layer structure to enhance the dynamic performance of fuel cells.

车用质子交换膜燃料电池的瞬态性能对系统的稳定性和耐久性具有重要意义。催化剂层是电化学反应的主要场所。然而，催化剂层中离子负载和碳含量对瞬态电性能和传质的影响机理尚不清楚。因此，本文建立了瞬态三维燃料电池模型与催化剂层团聚模型耦合。从氧输运、溶解水输运和溶解水分布均匀性等方面分析了离聚体和碳含量对溶液瞬态特性的影响。提出了综合性能系数和非均匀性系数来评价暂态性能。结果表明：离子含量越高，电流密度的超调幅度越大，响应时间越长，但溶解水分布非均质系数的波动幅度越小；当离子分数为0.3时，稳态电流密度比离子分数为0.5时提高了5.48%，电流密度超调幅度降低了16.61%。碳含量对稳态电学性能的影响大于对瞬态超调幅度的影响。此外，在高碳负荷下，细胞进入氧浓度主导阶段的速度较慢。由于负荷变化后局部电流密度和氧含量的降低主要发生在下游区域，因此下游区域的补氧至关重要。该研究为优化催化剂层结构以提高燃料电池的动态性能提供了一种有效的策略。

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引用次数: 0