Yazar "Ji, Xiaobo" seçeneğine göre listele

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  • Küçük Resim Yok
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    Architectures of zeolitic imidazolate framework derived Cu2Se/ZnSe@NPC and Cu1.95Se@NPC nanoparticles as anode materials for sodium-ion and lithium-ion batteries
    (Elsevier, 2025) Bugday, Nesrin; Huang, Jiangnan; Deng, Wentao; Zou, Guoqiang; Hou, Hongshuai; Ji, Xiaobo; Yasar, Sedat
    Transition metal selenides (TMSes) face challenges such as low electronic conductivity, significant volume expansion, and particle agglomeration during charge and discharge processes, limiting their practical application in batteries. A promising solution involves integrating a carbon matrix into TMS-based anodes, which can enhance conductivity and mitigate volume stress. In this study, we synthesized novel Cu Se/ZnSe@NPC and Cu Se@NPC nanoparticles, embedded in a nitrogen-doped porous carbon (NPC) network using zeolitic imidazolate framework-11 (ZIF-11) as a template, for the first time as anode materials in lithium-ion (LIBs) and sodium-ion batteries (SIBs). The Cu Se/ZnSe@NPC and Cu Se@NPC nanoparticles demonstrate impressive initial capacities of 762 and 712 mAh g-1 at 0.1 A g-1, respectively, and deliver specific capacities of 401 and 358 mAh g-1 at 0.3 A g-1 for lithium-ion half-cell batteries. For sodium-ion half-cell batteries, these materials achievesatisfactory initial capacities of 455 and 349 mAh g-1 at 0.1 A g-1, and exhibit exceptional cycling stability with capacities of 223 and 204 mAh g-1 after 1000 cycles at 2 A g-1, respectively.
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    Cu@MOF based composite materials: High performance anode electrodes for lithium-ion and sodium-ion batteries
    (Elsevier, 2024) Bugday, Nesrin; Deng, Wentao; Zou, Guoqiang; Hou, Hongshuai; Ji, Xiaobo; Yasar, Sedat
    In order to satisfy the increasing demand for energy, it is essential to improve the efficiency of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) batteries. Metal selenides (MSes) have a high theoretical specific capacity, can be designed in a variety of ways, conduct electricity well, can change morphology easily, and have a multi-electron reaction mechanism. These characteristics make them very competitive as anode materials for LIBs and SIBs. Herein, we synthesise Cu@MOF and Cu@NH2-MOF as the precursor to prepare Cu1.95Se embedded into porous carbon matrix (Cu1.95Se@PC) and porous-N-doped carbon matrix (Cu1.95Se@NPC) via pyrolysis process of Cu@MOF and Cu@NH2-MOF, respectively. Cu1.95Se@PC and Cu1.95Se@NPC electrodes for half-cell LIBs and SIBs exhibit a high reversible capacity of 313.1, 480.9 (for LIBs), 216.3 and 303.8 (for SIBs) mAhg(-1) after 1000 cycles at 2 A g(-1), respectively. We assess the electrochemical performance of the Cu1.95Se@PC and Cu1.95Se@NPC anodes by integrating them with commercially available LiFePO4 (LFP) into full-cell LIBs. The LFP//Cu1.95Se@PC and LFP//Cu1.95Se@NPC full-cells have discharge capacities of approximately 330 and 293 mAh g(-1) at 0.3 A g(-1) at the initial cycle. In order to explore the sodium storage mechanism of the Cu1.95Se composites, we conducted an in situ XRD test during the first charge/discharge cycle, considering their favourable cycling and rate performance. Our work provides a promising anode electrode material for both half-cell LIBs and SIBs with high volume utilization and superior electrochemical performances.
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    Hard carbon-encapsulated cobalt chalcogenides derived from waste apricot seed testa biomass: High performance anode electrode materials for Na-ion storage
    (Elsevier, 2025) Bugday, Nesrin; Onal, Yunus; Duygulu, Ozgur; Deng, Wentao; Ji, Xiaobo; Yasar, Sedat
    Anode materials are crucial in sodium-ion batteries (SIBs), and the advancement of low-cost, high-capacity, and cycle-stable anode materials is a primary objective in the progression of sodium-ion batteries. Carbon, derived from biomass has emerged as a prominent anode material for energy storage devices, attributed to its costeffectiveness and environmental sustainability. Given their limited capacities at elevated current densities, it is essential to create biomass-derived composites incorporating other components with high theoretical capacities. This study successfully embeds Co3O4, Co9S8, and Co3Se4 cobalt chalcogenide nanoparticles onto hard carbon derived from the biomass of waste apricot seed testa (WAST). Hard carbon coating reduces or inhibits the dissolution of Co3O4, Co9S8, and Co3Se4 cobalt chalcogenides in the electrolyte, thereby preventing capacity loss. The synthesized Co3O4@HC-WAST, Co9S8@HC-WAST, and Co3Se4@HC-WAST electrodes demonstrate excellent cycling stability and rate performance when test as sodium-ion battery anodes. The capacity of the best anode material, Co3Se4@HC-WAST, is maintained at 307.8 mAh g- 1 (5 A g- 1) after 750 cycles with 99 % Coulombic efficiency. This study outlines a method for the preparation and comparison of the electrochemical performance of composite hybrid materials comprising hard carbon and cobalt chalcogenides.
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    High-performance P2-Na0.67Mn0.85Cu0.15O2/Hard carbon full cell Na-ion battery: Pre-Sodiation of anode, p/n ratio optimizations, and Operando XAS studies
    (Pergamon-Elsevier Science Ltd, 2023) Altundag, Sebahat; Altin, Emine; Altin, Serdar; Ates, Mehmet Nurullah; Ji, Xiaobo; Sahinbay, Sevda
    Na-ion batteries have gained significant attention as a cost-effective and efficient energy storage option for large scale applications, serving as an alternative to the Li-ion batteries. However, commercialization of these batteries is still many steps away since most cathode materials suffer from significant capacity loss and more full-cell studies are required. In this work, we report the electrochemical properties of half-and full-cells of P2-type Na0.67Mn0.85Cu0.15O2 synthesized by solid state technique. X-ray diffraction, FT-IR, and Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy techniques are used to determine the structural properties. Surface properties are studied by X-ray photoelectron spectroscopy and Bru-nauer-Emmett-Teller techniques. Half cells and full cells were constructed with Na-metal and hard carbon, respectively. Na-ion diffusion kinetics at 10 degrees C, room temperature, and 50 degrees C were determined experimentally. Galvanostatic cycling tests on half-cells show capacity values of 165/124 mAh/g for the 1./100. cycles with 24.8 % capacity fade. Operando x-ray absorption spectroscopy measurements were utilized to study local structural modification around transition metal ions during charge/discharge. In the full-cell studies, electrode mass ratio (p/n) and parameters for presodiation of hard carbon were optimized. Using 30 mA/g current density, the un-processed and the pre-sodiated full-cells reach capacity values of 48 mAh/g (p/n = 2.5) and 150 mAh/g (p/n = 0.75 and 1.15), respectively.
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    MOF-derived SnSe/carbon composite anode materials for Li-ion and Na-ion batteries
    (Nonferrous Metals Soc China, 2025) Bugday, Nesrin; Deng, Wentao; Duygulu, Ozgur; Zou, Guoqiang; Hou, Hongshuai; Ji, Xiaobo; Yasar, Sedat
    Metal selenides (MSs) are attracted considerable interest as potential anode electrode materials for Li-ion/Na-ion batteries (LIBs/SIBs) owing to their elevated theoretical capacity and superior conductivity. Nevertheless, their potential is constrained by inadequate capacity retention and inferior longevity, principally due to volumetric expansion and undesirable structural failure caused by the insertion and extraction of comparatively large Li+/Na+ ions during charging and discharging. Therefore, three different composites containing SnSe and one more metal selenide are synthesized using metal-organic framework (MOF) to enhance the accommodation of Li/Na ions and provide adequate ion routes. The Co3Se4/SnSe@NPC material demonstrates exceptional cyclic stability and rate capability as anode material for LIBs and SIBs (603 mAh g-1 after 1000 cycles at 2 A g-1 (for LIBs) and 296 mAh g-1 after 1000 cycles at 2 A g-1 (for SIBs)). This electrochemical performance enhancement may be attributed to the improved conductivity of the composite structure and introduction of SnSe, which facilitates the transfer of electrons within the structure. In addition, selenium- and nitrogen-doped mesoporous carbon architectures facilitate electrolyte penetration in active materials, enhance contact area, promote effective diffusion of Li+ or Na+ within the composite, and mitigate volume expansion during the charge-discharge cycle. Consequently, the Co3Se4/SnSe@NPC composite offers a novel perspective on the advancement of anode materials for LIBs and SIBs. (sic)(sic)(sic)(sic)(sic) (MSs)(sic)(sic)(sic)(sic)(sic)/(sic)(sic)(sic)(sic)(sic) (LIBs/SIBs)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)Li+/Na+(sic)(sic) (sic)(sic)/(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic) (MOF)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)SnSe (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)Li/Na (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic), Co3Se4/SnSe@NPC (sic)(sic)(sic)(sic)(sic)LIBs (sic)SIBs (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)(sic)(sic)((sic)2 A g-1 (sic)(sic)(sic)(sic)(sic)(sic),LIBs (sic)(sic)1000 (sic)(sic)(sic)(sic)(sic)(sic)(sic)603 mAh g-1;SIBs (sic)(sic)1000 (sic)(sic)(sic)(sic)(sic)(sic)(sic)296 mAh g-1).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)SnSe (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic),(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic) Li+/Na+(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic), Co3Se4/SnSe@NPC (sic)(sic)(sic)(sic)(sic)LIBs (sic)SIBs (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).
  • Küçük Resim Yok
    Öğe
    Outstanding electrochemical and long cycle performance of the transition metal selenides embedded in porous carbon
    (Elsevier Science Sa, 2025) Bugday, Nesrin; Deng, Wentao; Duygulu, Ozgur; Ji, Xiaobo; Yasar, Sedat
    Transition-metal selenides are drawn significant attention owing to their high energy density and theoretical capacity. Nonetheless, their inadequate conductivity, poor cycling stability, subpar rate performance, and volume expansion impede their practical application in battery systems. We effectively synthesize core-shell Cu2Se/ZnSe@NPC, Cu2Se@NPC, and Cu2Se/Co3Se4@NPC composite heterostructures utilizing ZIF-8 and ZIF-67 as precursors. The Cu2Se, ZnSe, and Co3Se4 nanoparticles added to the N-doped porous carbon (NPC) structure provide enormous active sites for the electrodes in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). We belive that, the N-doped porous carbon (NPC) reduces the volume change impact created during the cycle process while simultaneously improving the conductivity. The Cu2Se/Co3Se4@NPC composite shows better performance and stability for SIBs, while the Cu2Se/ZnSe@NPC is outstanding for LIBs. Cu2Se/Co3Se4@NPC, Cu2Se/ZnSe@NPC, and Cu2Se@NPC electrodes exhibit a high initial capacity of 1507, 798, and 1023 mAh g-1 for LIBs, respectively. For SIBs after 1000 cycles, the capacities of the materials maintain at 310, 237, and 181 mAh g-1, respectively. Furthermore, the Cu2Se/ZnSe@NPC, Cu2Se@NPC, and Cu2Se/Co3Se4@NPC composites demonstrate exceptional rate performance for SIBs and LIBs. The reaction kinetics of Li/Na ions in the Cu2Se/ ZnSe@NPC, Cu2Se@NPC, and Cu2Se/Co3Se4@NPC composites are examined to elucidate their exceptional electrochemical performance. The results show the great potential of these composites and help us understand how different metal selenides, both alone and in different combinations, affect the creation of effective LIBs and SIBs.
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    Sustainable chickpea stem-inspired cobalt chalcogenide-carbon composites as ultra-stable anodes for sodium-ion batteries and hybrid capacitors
    (Elsevier, 2026) Bugday, Nesrin; Onal, Yunus; Duygulu, Ozgur; Deng, Wentao; Ji, Xiaobo; Yasar, Sedat
    The improvement of sustainable and high-performance anodes is essential for the future of sodium-ion energy storage systems (SIESS). Transition metal chalcogenides (TMCs) as anode have become a focal point of research because to their substantial capability facilitated by conversion or alloying reactions. Herein, metallic cobalt nanoparticles supported on the chickpea stem derived carbon (Co@CSC) underwent controlled oxidation, sulfurization, and selenization to form cobalt chalcogenides/carbon (Co3O4@CSC, Co9S8@CSC, and Co3Se4@CSC) composites. Electrochemical evaluation of these composites for sodium-ion batteries (SIBs) reveals reversible capacity of 586 mAh g(-1) at a current density of 0.1 A g(-1), along with remarkable rate performance of 370 mAh g(-1) at 2.0 A g(-1) and long-term stability after 1000 cycles for Co9S8@CSC. In contrast, the Co3Se4@CSC shows dominant pseudocapacitive contributions, enhancing both reversibility and long-term stability. Practical applicability is confirmed in full cells employing Na3V2(PO4)(3) cathodes: the Co3Se4@CSC//Na3V2(PO4)(3) configuration delivered capacity of 146 mAh g(-1) at a current density of 0.1 A g(-1). According to hybrid capacitor tests, Co3Se4@CSC surpass Co9S8@CSC by providing greater reversible capacity (similar to 85 mAh g(-1)) and steadier voltage profiles. Robust coupling between the cobalt chalcogenides and the conductive porous carbon promote efficient charge transport, preserved structural integrity during cycling, and enhanced redox kinetics.
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    Öğe
    Unveiling the outstanding full-cell performance of P2-type Na0.67(Mn0.44Ni0.06Fe0.43Ti0.07)O2 cathode active material for Na-ion batteries
    (Elsevier, 2024) Kalyoncuoglu, Burcu; Ozgul, Metin; Altundag, Sebahat; Harfouche, Messaoud; Oz, Erdinc; Avci, Sevda; Ji, Xiaobo
    In this study, we unravel the effect of Ni doping on the half-cell and full-cell performances of the Na0.67Mn0.5-xNixFe0.43Ti0.07O2 cathode materials where x varies between 0.02 and 0.1. The cyclic voltammetry (CV) analysis of the half-cells is performed at 10 degrees C, room temperature (RT), and 50 degrees C to elucidate the redox reaction mechanisms at different temperatures. Among the studied cathodes, the highest specific capacity is obtained fox = 0.06 which delivered a specific capacity of 186 mAh g-1 at C/3-rate. The full cell of Na0.67Mn0.44Ni0.06-Fe0.43Ti0.07O2/hard carbon couple is assembled in coin cell format and the specific capacity of the cell at C/2, 1C, and 2C rates are found as 153 mAh g- 1, 125 mAh g-1 and 120 mAh g-1, respectively. At the C/2-rate, the excellent capacity retention of the full cell is around 70% after 500 cycles delivering a specific capacity of 103 mAh g- 1. Along with the conventional physicochemical characterization methods such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Raman and Fourier-transform Infrared Spectroscopies (FTIR), we also utilize X-ray photoelectron spectroscopy (XPS) to bridge the nexus between the performance and the structure properties of the studied materials. Furthermore, we also employ synchrotron-based X-ray Absorption (XAS) to understand the local geometry of the optimized cathode materials in operando.
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    ZIF-12-derived N-doped Fe/Co/S/@C nanoparticles as high-performance composite anode electrode materials for lithium-ion batteries
    (Elsevier Science Sa, 2022) Bugday, Nesrin; Ates, Mehmet Nurullah; Duygulu, Ozgur; Deng, Wentao; Ji, Xiaobo; Altin, Serdar; Yasar, Sedat
    Different sulfide species of both iron and cobalt metals (FeS2, FeS, CoS, and FeCoS2) are composed together in N-doped porous carbon (NPC) for the synthesis of composite anode materials (labeled as Fe/Co/S@NPC-T hereafter, T = 700, 800, 900) by sulfurization and pyrolysis of Fe/Co-based zeolitic imidazolate framework (ZIF-12). Their structural properties are investigated by XRD, FTIR, SEM, TEM, BET and XPS analysis, and Fe/ Co/S@NPC-T composite materials, heat treated at different temperatures, are used as anode materials in rechargeable lithium-ion batteries. According to XRD results, the heat treatment of the Fe/Co@ZIF-12/S heat treated at 900 ? leads to the formation of the FeCoS2 phase (66 %) along with CoS (33 %) phase impurity. The heat treatment of the Fe/Co@ZIF-12/S heat treated at 800 ? causes the formation of the main phase of FeCoS2 with minor impurity phases of CoS and FeS2. However, pyrolysis of the Fe/Co@ZIF-12/S heat treated at 700 & DEG;C leads to the formation of the FeCoS2, CoS, FeS, and FeS2 phases. Among the samples, the highest BET surface area is 53.4 m2/g for the Fe/Co/S@NPC-90 0 sample. The CV analysis of the battery cell shows anodic and cathodic redox peaks, which belong to the redox reaction of CoS, FeS2, and FeS. The first dis-charge capacities of the cells for Fe/Co/S@NPC-70 0, Fe/Co/S@NPC-80 0 and Fe/Co/S@NPC-90 0 are 395, 963, 574 mA h/g at 300 mA/g, and 229, 835 and 1024 mA h/g at 1000 mA/g, respectively. (c) 2022 Elsevier B.V. All rights reserved.