Electrochimica Acta最新文献

英文中文

Electrochemical Reduction Mechanism of 4-Nitrobenzyl Bromide in Ionogel Membranes

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-14 DOI: 10.1016/j.electacta.2025.146232

Tehreema Naeem, Silvia Mena, Jordi Hernando, Gonzalo Guirado

Ionic liquid-based electrolytes (ILs) have gained tremendous attention as sustainable, green electrolytes for electrochemical processes due to their negligible vapour pressure and high boiling points. A rising trend is to fabricate solid electrolytes based on ionic liquids to address the risk of leakage associated to liquid electrolytes. These solid electrolytes, which are commonly known as ionogel membranes (IGs), contain the intrinsic properties of ILs, while having excellent mechanical strength. These characteristics make them ideal for investigating reaction mechanisms and facilitating electrosynthesis processes. By providing a stable and conductive environment, ionogels enable precise control and monitoring of electrochemical reactions in solid electrolytes, leading to more accurate and reproducible results. Their application not only enhances our understanding of fundamental electrochemical processes but also paves the way for innovative advancements in electrosynthesis, contributing significantly to the development of new materials and technologies. In this body of research, the reduction mechanism of p-nitrobenzyl bromide (p-NBBr) is studied and disclosed in IG membranes for a first time. We successfully performed a controlled potential electrolysis of p-NBBr in IG membranes, as well as studying two different electrochemical setups to obtain the most optimal configuration. We also demonstrate that the addition of electrolyte additives, such as lithium bis(trifluorometahnesulfonyl)imide (Li TFSI), in the IG composition raises the ionic conductivity of the resulting membrane from 0.15 up to 0.2 mS/cm.

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引用次数: 0

A Pd–Pt-based bulk nanoporous alloy with continuous solubility for hydrogen

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-13 DOI: 10.1016/j.electacta.2025.146106

Sambit Bapari , Jörg Weissmüller

Metal hydrides that enable reversible solute exchange with a reservoir often exhibit a miscibility gap at room temperature. Misfit strain during two-phase coexistence may then lead to degradation on repeated charging/discharging cycles. Furthermore, the miscibility gap impairs continuous and uniform composition tuning for functional applications. We explore electrochemical dealloying as a pathway to macroscopic monolithic samples of nanoporous Pd–Pt with continuous solubility for H at room temperature. The ligament size is tunable in the range of 4–40 nm, and sorption isotherms suggest a miscibility-gap critical point marginally below room temperature. With a maximum hydrogen fraction of 0.5, we demonstrate a reversible actuation strain of 3.3 % and a high cycle stability.

引用次数: 0

One-pot exfoliation with simultaneous functionalization of graphene via wireless polarization

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-13 DOI: 10.1016/j.electacta.2025.146230

Anastasiia Bazylevska , Zviadi Zarkua , Giel Arnauts , Lino da Costa Pereira , Rob Ameloot , Miriam C. Rodríguez González , Steven De Feyter

The field of 2D materials has rapidly grown and has expanded further by the tunability of their unique properties for device fabrication. Covalent functionalization, such as spontaneous grafting and electrografting, has been employed to enhance dispersibility and optimize performance for various applications; however, several challenges still remain. Current methods often require reactive conditions that hinder control over modification uniformity or rely on conductive materials, limiting scalability. This work introduces a one-pot protocol for exfoliating and functionalizing 2D materials using wireless polarization, demonstrated with graphene. The method is conducted in water without using surfactants or toxic solvents and produces high-quality exfoliated graphene flakes, confirmed via transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Functionalization with diazonium chemistry is validated through XPS and thermogravimetric analysis combined with mass spectrometry, showcasing successful grafting. The scalable, versatile wireless approach has the potential to be applicable to a wide range of 2D materials and organic functionalization methods, offering the prospect for industrial integration and broadening possibilities in device applications.

二维材料领域发展迅猛，其独特性能的可调性进一步拓展了设备制造领域。共价官能化，如自发接枝和电接枝，已被用于提高分散性和优化各种应用的性能；然而，仍然存在一些挑战。目前的方法通常需要反应条件，这阻碍了对修饰均匀性的控制，或者依赖于导电材料，限制了可扩展性。本研究以石墨烯为例，介绍了一种利用无线极化对二维材料进行剥离和功能化的单锅协议。通过透射电子显微镜、原子力显微镜、X 射线光电子能谱（XPS）和拉曼光谱证实，该方法可在水中进行，无需使用表面活性剂或有毒溶剂，并能产生高质量的剥离石墨烯薄片。通过 XPS 和热重分析结合质谱法验证了重氮化学的功能化，展示了成功的接枝。这种可扩展的多功能无线方法有可能适用于各种二维材料和有机功能化方法，为工业集成提供了前景，并拓宽了设备应用的可能性。

{"title":"One-pot exfoliation with simultaneous functionalization of graphene via wireless polarization","authors":"Anastasiia Bazylevska , Zviadi Zarkua , Giel Arnauts , Lino da Costa Pereira , Rob Ameloot , Miriam C. Rodríguez González , Steven De Feyter","doi":"10.1016/j.electacta.2025.146230","DOIUrl":"10.1016/j.electacta.2025.146230","url":null,"abstract":"<div><div>The field of 2D materials has rapidly grown and has expanded further by the tunability of their unique properties for device fabrication. Covalent functionalization, such as spontaneous grafting and electrografting, has been employed to enhance dispersibility and optimize performance for various applications; however, several challenges still remain. Current methods often require reactive conditions that hinder control over modification uniformity or rely on conductive materials, limiting scalability. This work introduces a one-pot protocol for exfoliating and functionalizing 2D materials using wireless polarization, demonstrated with graphene. The method is conducted in water without using surfactants or toxic solvents and produces high-quality exfoliated graphene flakes, confirmed via transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Functionalization with diazonium chemistry is validated through XPS and thermogravimetric analysis combined with mass spectrometry, showcasing successful grafting. The scalable, versatile wireless approach has the potential to be applicable to a wide range of 2D materials and organic functionalization methods, offering the prospect for industrial integration and broadening possibilities in device applications.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"527 ","pages":"Article 146230"},"PeriodicalIF":5.5,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143827468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Zinc metal free polymer-based anode materials for ultralong aqueous zinc-ion rechargeable battery

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-12 DOI: 10.1016/j.electacta.2025.146211

Gouri Sankar Das , Komal Kumari , Phulladweepa Patra , Prabakaran Swaminathan , Somnath Ghosh

Aqueous Zn-ion batteries (AZIBs) have garnered significant attention for grid-level energy storage systems owing to their high safety, cost-effectiveness and environmental friendliness. However, the practical application of the AZIBs always suffers from uncontrollable Zn dendrite growth, low coulombic efficiency and the irreversible kinetics of electrodes. Herein, we propose a highly zincophilic organic polyimide-decorated graphene (PI/G) anode synthesized through straightforward polycondensation reactions featuring an optimized electronic structure with a π-conjugated network. The well-organized, high-density diimide groups in PI/G material offer more accessible electrochemically active sites and reduce the energy barrier for ion diffusion as supported by electrochemical, ex-situ characterizations and density functional theory (DFT) simulations. The synthesized PI/G anode provides a low redox potential, high specific capacity and fast rate capability. When a full AZIB is fabricated by the pairing of polymer anode with ZnMn₂O₄ cathode, the resulting dendrite-free device provides a remarkable specific capacity and ultra-long cycle stability, retaining 84 % of its capacity at 10 A g⁻¹ even after 50,000 cycles. This stability is achieved through a reversible Zn²⁺ co-participative phase transfer mechanism at redox-active sites. This study hopes to pave the way for an alternative design and development strategy for practical AZIB applications in large-scale grid energy storage systems.

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引用次数: 0

Simplified synthesis of N, S co-doped ordered mesoporous carbon cathode via a one-step impregnation technique for superior Zn-ion hybrid supercapacitors

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-12 DOI: 10.1016/j.electacta.2025.146228

Shenghai Zhou, Na Liang, You Zhang, Xiangxiu Liu, Dongxu Ge, Hongbo Xu

Aqueous zinc-ion hybrid supercapacitors (ZHSCs) are emerging as promising energy storage devices due to their safety and low cost. The development of cathode materials with superior performance has become a focal point in ZHSC research. Herein, N, S co-doped ordered mesoporous carbons (N, S-OMC) were synthesized via a one-step impregnation of pyrrole and 2-thiophenemethanol into the mesopores of silica templates. The effect of the pyrrole-to-2-thiophenemethanol feed ratio on the microstructure and electrochemical performance of N, S-OMC was examined. The optimal electrochemical performance of N, S-OMC-25 can be attributed to the synergistic effects of well-controlled N and S doping levels, high content of pyridine N, numerous defect sites, good conductivity, ordered mesoporous channels, and a large surface area, all of which provide numerous accessible active sites for charge storage and enhanced electrochemical kinetics in ZHSCs. The N, S-OMC-25-based ZHSCs device demonstrated a high specific capacity (269 ± 1 F/g), high energy density (82 Wh/kg), and outstanding cyclic stability, retaining 95 % capacity after 10,000 cycles in 1 M ZnSO₄ and 95 % after 60,000 cycles in 3 M Zn(CF₃SO₃)₂. This work simplifies the preparation of N, S-OMC via the template method and introduces N, S-OMC carbon materials for use in aqueous ZHSCs devices.

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引用次数: 0

Mesoporous carbon materials doped with Co, Fe and nitrogen as oxygen reduction reaction electrocatalysts for anion-exchange membrane fuel cell

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-11 DOI: 10.1016/j.electacta.2025.146226

Johanna Katariina Piir , Jaana Lilloja , Maike Käärik , Jekaterina Kozlova , Arvo Kikas , Alexey Treshchalov , Jaan Aruväli , Vambola Kisand , Jaan Leis , Kaupo Kukli , Kaido Tammeveski

Mesoporous carbons (MCs) are prepared using dual-templating and doped with cobalt, iron and nitrogen for electrocatalytic applications and are characterised using various physico-chemical methods. Prepared materials are employed as oxygen reduction reaction (ORR) electrocatalysts and cathode catalysts of an anion-exchange membrane fuel cell (AEMFC). The MC materials are prepared using two novel and sustainable phenolic resin synthesis routes, while employing an easily removable soft template and MgO as a hard template to obtain feasible mesoporous texture. The content of MgO is varied in dual-templating to assess its influence on the porous structure and electrocatalytic properties. Doping is done via high-temperature pyrolysis using cobalt and iron acetate as transition metal sources and 1,10-phenanthroline as a nitrogen source. The physico-chemical characterisation shows that the preparation of MC materials and their subsequent doping has been successful. The initial assessment employing the rotating disc electrode method indicates that the synthesised catalyst materials exhibit very high electrocatalytic activity towards the ORR in alkaline media and good stability by applying 10,000 potential cycles. In AEMFC testing, the most promising cathode catalyst reveals excellent fuel cell performance by obtaining a peak power density above 500 mW cm^–2, almost the same performance as with commercial mesoporous Fe-N-C catalyst. Thus, the novel dual-templating approach taken herein enables to prepare sustainable non-precious metal electrocatalysts with feasible porous characteristics for the AEMFC application.

采用双模板法制备了用于电催化应用的介孔碳 (MC)，并在其中掺杂了钴、铁和氮。制备的材料被用作氧还原反应（ORR）电催化剂和阴离子交换膜燃料电池（AEMFC）的阴极催化剂。MC 材料的制备采用了两种新颖且可持续的酚醛树脂合成路线，同时采用了易于去除的软模板和氧化镁作为硬模板，以获得可行的介孔质地。在双模板中，氧化镁的含量有所不同，以评估其对多孔结构和电催化性能的影响。采用钴和醋酸铁作为过渡金属源，1,10-菲罗啉作为氮源，通过高温热解进行掺杂。物理化学特性分析表明，MC 材料的制备和随后的掺杂都很成功。采用旋转圆盘电极法进行的初步评估表明，合成的催化剂材料在碱性介质中对 ORR 具有极高的电催化活性，并且在 10,000 次电位循环中具有良好的稳定性。在 AEMFC 测试中，最有前途的阴极催化剂显示出卓越的燃料电池性能，峰值功率密度超过 500 mW cm-2，与商用介孔 Fe-N-C 催化剂的性能几乎相同。因此，本文所采用的新颖双模板方法能够制备出具有可行多孔特性的可持续无贵金属电催化剂，用于 AEMFC 应用。

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引用次数: 0

Electrochemical conversion of thin layer amorphous carbon to graphite nanosheets as conductive agents for silicon anode

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-11 DOI: 10.1016/j.electacta.2025.146227

Ruoyu Sang , Zesheng Wu , Zhiyong Wang , Xianbo Jin

Silicon is considered as an ideal high-capacity alloy-type anode material for lithium-ion batteries. To address its inherent issues of volume expansion and poor conductivity, various strategies for preparing silicon composite materials have been developed. However, three dimensional porous structured conductive agents may address these two drawbacks simultaneously. In this work, a thin-layer perylenetetracarboxylic dianhydride-derived carbon (PDC) is electrochemically converted into highly crystalline and porous graphite (PDG), which shows about 2.6 times larger pore volume and 28 times higher conductivity than common conductive agent acetylene black (AB). When used as a conductive agent for nanosilicon anodes, PDG endows the electrode with excellent cycling stability and high-rate performance. This work promises a new kind of conductive agents that significantly improve the performance of silicon-based anodes.

硅被认为是锂离子电池理想的高容量合金型负极材料。为了解决硅体积膨胀和导电性差的固有问题，人们开发了各种制备硅复合材料的策略。然而，三维多孔结构导电剂可以同时解决这两个缺点。在这项研究中，薄层过烯四羧酸二酐衍生碳（PDC）通过电化学方法转化为高结晶多孔石墨纳米片（PDG），其孔隙体积比普通导电剂乙炔黑（AB）大约 2.6 倍，导电率则高出 28 倍。当用作纳米硅阳极的导电剂时，PDG 使电极具有出色的循环稳定性和高速性能。这项研究有望开发出一种新型导电剂，显著提高硅基阳极的性能。

引用次数: 0

Electrochemical oxidation and reduction of sodium electrolytes tracked by in-situ/ex-situ magnetic resonance spectroscopy and computational modelling

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-11 DOI: 10.1016/j.electacta.2025.146191

R. Kukeva , G. Vassilev , M. Kalapsazova , H. Rasheev , A. Tadjer , S. Simova , R. Stoyanova

Understanding the degradation processes of the sodium electrolyte at the individual level is a key safety issue for extending the cycle life of sodium-ion batteries. This study proposes in-situ EPR and ex-situ NMR tools, complemented by computational modelling, as a universal methodology for the investigation of electrolyte degradation, eliminating the effect of the electrode surface. While in-situ EPR enables the detection of intermediate radical species, ex-situ NMR reveals the final degradation products. The assignment of the EPR signals is based on DFT calculations. To discriminate the effects of the electrolyte salt and solvent on the degradation reactions, three of the most promising sodium electrolytes are investigated, namely sodium hexafluorophosphate, NaPF₆, dissolved in propylene carbonate, PC, and in the binary propylene/ethylene carbonate, PC/EC, and sodium perchlorate, NaClO₄, dissolved in PC. Finally, the identified initial and final degradation products are integrated into the possible pathways of electrolyte reduction and oxidation. Thus, the most appropriate scheme of sodium electrolyte oxidation and reduction is proposed. In general, this radical-driven mechanism of electrolyte degradation could help to rationalise the effect of real electrode surfaces on the electrochemical side reactions that occur at both high and low voltages, as well as during cell ageing.

{"title":"Electrochemical oxidation and reduction of sodium electrolytes tracked by in-situ/ex-situ magnetic resonance spectroscopy and computational modelling","authors":"R. Kukeva , G. Vassilev , M. Kalapsazova , H. Rasheev , A. Tadjer , S. Simova , R. Stoyanova","doi":"10.1016/j.electacta.2025.146191","DOIUrl":"10.1016/j.electacta.2025.146191","url":null,"abstract":"<div><div>Understanding the degradation processes of the sodium electrolyte at the individual level is a key safety issue for extending the cycle life of sodium-ion batteries. This study proposes <em>in-situ</em> EPR and <em>ex-situ</em> NMR tools, complemented by computational modelling, as a universal methodology for the investigation of electrolyte degradation, eliminating the effect of the electrode surface. While <em>in-situ</em> EPR enables the detection of intermediate radical species, <em>ex-situ</em> NMR reveals the final degradation products. The assignment of the EPR signals is based on DFT calculations. To discriminate the effects of the electrolyte salt and solvent on the degradation reactions, three of the most promising sodium electrolytes are investigated, namely sodium hexafluorophosphate, NaPF<sub>6</sub>, dissolved in propylene carbonate, PC, and in the binary propylene/ethylene carbonate, PC/EC, and sodium perchlorate, NaClO<sub>4</sub>, dissolved in PC. Finally, the identified initial and final degradation products are integrated into the possible pathways of electrolyte reduction and oxidation. Thus, the most appropriate scheme of sodium electrolyte oxidation and reduction is proposed. In general, this radical-driven mechanism of electrolyte degradation could help to rationalise the effect of real electrode surfaces on the electrochemical side reactions that occur at both high and low voltages, as well as during cell ageing.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"526 ","pages":"Article 146191"},"PeriodicalIF":5.5,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lithium-ion battery separators based on sustainable collagen and chitosan hybrid membranes

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-11 DOI: 10.1016/j.electacta.2025.146087

Mireia Andonegi , João P. Serra , Maria M. Silva , Renato Gonçalves , Carlos M. Costa , Senentxu Lanceros-Mendez , Koro de la Caba , Pedro Guerrero

This work focuses on the production of sustainable membranes based on collagen and chitosan as separators in lithium-ion batteries. Membranes were prepared by freeze-drying with varying collagen and chitosan contents. All membranes show interconnected pores with different pore sizes and porosity above 90 %, allowing high values of electrolyte uptake. As for thermal and mechanical characteristics, the addition of chitosan improves both thermal and mechanical stability. After 1 M LiPF₆ in EC:DMC electrolyte uptake, the ionic conductivity is above 0.49 mS·cm^-1 for all membranes and is most affected by the collagen content. Furthermore, the membranes present a lithium transfer number value of 0.2. In cathodic half-cells with LiFePO₄, the obtained room temperature discharge capacity is above 140 mAh·g^-1 at C/8 rate. For high C rates (C and 2C rates), the membranes with 80 wt % of collagen and 20 wt % of chitosan present 42 mAh·g^-1 after 100 cycles at C rate, demonstrating adequate reversibility. Considering the need for more environmentally friendly materials and methods compatible with a circular economy, the bio-based membranes developed in this work constitute an alternative for synthetic separators.

{"title":"Lithium-ion battery separators based on sustainable collagen and chitosan hybrid membranes","authors":"Mireia Andonegi , João P. Serra , Maria M. Silva , Renato Gonçalves , Carlos M. Costa , Senentxu Lanceros-Mendez , Koro de la Caba , Pedro Guerrero","doi":"10.1016/j.electacta.2025.146087","DOIUrl":"10.1016/j.electacta.2025.146087","url":null,"abstract":"<div><div>This work focuses on the production of sustainable membranes based on collagen and chitosan as separators in lithium-ion batteries. Membranes were prepared by freeze-drying with varying collagen and chitosan contents. All membranes show interconnected pores with different pore sizes and porosity above 90 %, allowing high values of electrolyte uptake. As for thermal and mechanical characteristics, the addition of chitosan improves both thermal and mechanical stability. After 1 M LiPF<sub>6</sub> in EC:DMC electrolyte uptake, the ionic conductivity is above 0.49 mS·cm<sup>-1</sup> for all membranes and is most affected by the collagen content. Furthermore, the membranes present a lithium transfer number value of 0.2. In cathodic half-cells with LiFePO<sub>4</sub>, the obtained room temperature discharge capacity is above 140 mAh·g<sup>-1</sup> at C/8 rate. For high C rates (C and 2C rates), the membranes with 80 wt % of collagen and 20 wt % of chitosan present 42 mAh·g<sup>-1</sup> after 100 cycles at C rate, demonstrating adequate reversibility. Considering the need for more environmentally friendly materials and methods compatible with a circular economy, the bio-based membranes developed in this work constitute an alternative for synthetic separators.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"526 ","pages":"Article 146087"},"PeriodicalIF":5.5,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A modification strategy for synthesizing single-crystal LiNi0.6Co0.2Mn0.2O2 with superior electrochemical performance

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta

Pub Date : 2025-04-11 DOI: 10.1016/j.electacta.2025.146225

Xinxin Zhao , Qixuan Ruan , Yuliang Li , Boning Li , Xiaoyan Yan , Xiaohua Zhang , Huiqin Chen , Jianhua Fan

Monocrystalline Ni-rich layered oxide is a promising cathode material with excellent cyclic stability attributed to the absence of grain boundaries. However, the majority of single-crystal LiNi_xCo_yMn_1-x-yO₂ (NCM) cathodes are prepared by the traditional high-temperature solid-phase method displays "quasi single crystals" formed through particle aggregation, and then the true single crystals can be obtained through subsequent ball milling or air crushing, leading to irregular and uneven morphology. Herein, we synthesize microsized single-crystal LiNi_0.6Co_0.2Mn_0.2O₂ (SC 622) materials utilize a modified molten-salt method, which using LiOH·H₂O and Li₂SO₄ as molten agent. Furthermore, the influence of the ratio of LiOH·H₂O and Li₂SO₄ on the morphology and electrochemical properties of LiNi_0.6Co_0.2Mn_0.2O₂ cathode is studied firstly in detail. Multiple characterization results manifested that the SC 622 material when prepared by using the molar ratio of Li₂SO₄ to LiOH·H₂O is 1:12 (SC 622–12) exhibits superior electrochemical performance. The SC 622–12 displays a specific capacity of 185.1 mAh g⁻¹ at 0.1 C and 123.4 mAh g⁻¹ at 5 C rate under the voltage range of 2.7–4.3 V. The capacity retention rates were 93.2 % and 91.7 % after 200 cycles at 1 C and 5 C, respectively. This work confirmed that the single-crystal NCM can be prepared by an effective molten-assisted strategy and can guide the synthesis of other cathode materials.

单晶富镍层状氧化物是一种前景广阔的阴极材料，由于不存在晶界而具有出色的循环稳定性。然而，大多数单晶 LiNixCoyMn1-x-yO2 （NCM）阴极都是采用传统的高温固相法制备的，通过颗粒聚集形成 "准单晶"，然后通过后续的球磨或空气粉碎才能获得真正的单晶，从而导致形貌不规则、不均匀。在此，我们采用改良的熔盐法合成了微小尺寸的单晶 LiNi0.6Co0.2Mn0.2O2 (SC 622) 材料，该方法使用 LiOH-H2O 和 Li2SO4 作为熔剂。此外，还首次详细研究了 LiOH-H2O 和 Li2SO4 的比例对 LiNi0.6Co0.2Mn0.2O2 阴极形貌和电化学性能的影响。多种表征结果表明，使用 Li2SO4 与 LiOH-H2O 的摩尔比为 1:12 制备的 SC 622 材料（SC 622-12）具有优异的电化学性能。在 2.7-4.3 V 的电压范围内，SC 622-12 在 0.1 C 时的比容量为 185.1 mAh g-1，在 5 C 时的比容量为 123.4 mAh g-1。这项研究证实，单晶 NCM 可通过有效的熔融辅助策略制备，并可指导其他阴极材料的合成。

{"title":"A modification strategy for synthesizing single-crystal LiNi0.6Co0.2Mn0.2O2 with superior electrochemical performance","authors":"Xinxin Zhao , Qixuan Ruan , Yuliang Li , Boning Li , Xiaoyan Yan , Xiaohua Zhang , Huiqin Chen , Jianhua Fan","doi":"10.1016/j.electacta.2025.146225","DOIUrl":"10.1016/j.electacta.2025.146225","url":null,"abstract":"<div><div>Monocrystalline Ni-rich layered oxide is a promising cathode material with excellent cyclic stability attributed to the absence of grain boundaries. However, the majority of single-crystal LiNi<sub>x</sub>Co<sub>y</sub>Mn<sub>1-x-y</sub>O<sub>2</sub> (NCM) cathodes are prepared by the traditional high-temperature solid-phase method displays \"quasi single crystals\" formed through particle aggregation, and then the true single crystals can be obtained through subsequent ball milling or air crushing, leading to irregular and uneven morphology. Herein, we synthesize microsized single-crystal LiNi<sub>0.6</sub>Co<sub>0.2</sub>Mn<sub>0.2</sub>O<sub>2</sub> (SC 622) materials utilize a modified molten-salt method, which using LiOH·H<sub>2</sub>O and Li<sub>2</sub>SO<sub>4</sub> as molten agent. Furthermore, the influence of the ratio of LiOH·H<sub>2</sub>O and Li<sub>2</sub>SO<sub>4</sub> on the morphology and electrochemical properties of LiNi<sub>0.6</sub>Co<sub>0.2</sub>Mn<sub>0.2</sub>O<sub>2</sub> cathode is studied firstly in detail. Multiple characterization results manifested that the SC 622 material when prepared by using the molar ratio of Li<sub>2</sub>SO<sub>4</sub> to LiOH·H<sub>2</sub>O is 1:12 (SC 622–12) exhibits superior electrochemical performance. The SC 622–12 displays a specific capacity of 185.1 mAh g<sup>−1</sup> at 0.1 C and 123.4 mAh g<sup>−1</sup> at 5 C rate under the voltage range of 2.7–4.3 V. The capacity retention rates were 93.2 % and 91.7 % after 200 cycles at 1 C and 5 C, respectively. This work confirmed that the single-crystal NCM can be prepared by an effective molten-assisted strategy and can guide the synthesis of other cathode materials.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"526 ","pages":"Article 146225"},"PeriodicalIF":5.5,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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