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• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/12730
  Investigation of the Effects of Low-Temperature Thermal Treatment Applied to Graphite in Spent Lithium-Ion Anode Recycling

  Kara, Adem; Temur, Hakan

  As the use of lithium-ion batteries (LIB) increases rapidly, recovery of graphite, the main component of the anode, from spent batteries has become important from environmental and economic perspectives. In this study, an acid leaching step followed by thermal treatment under partial atmosphere at a relatively low calcination temperature was investigated to recover graphite from spent lithium-ion batteries. The molecular and chemical structures of the recovered graphite in all spent anode samples were investigated using FTIR, ICP-MS, XRD, SEM–EDX and TEM–EDX. It was observed that organic impurities and volatile components were largely removed after acid leaching and thermal treatment at 750 °C. In addition, it was observed that graphite layers were rearranged and the distance between the layers decreased under the effect of thermal treatment. Partial atmosphere calcination at 750 °C can be considered as a feasible method for graphite recovery, offering energy efficiency and scalability. However, in an efficient calcination, it is necessary to maintain controlled oxygen levels to prevent excessive graphite loss and to perform preliminary acid leaching to reduce metal impurities. In order to best recycle graphite in waste lithium-ion anode recovery, a balance must be achieved between temperature, energy efficiency and material recovery. Considering this balance, a calcination temperature of 750 °C appears to be preferable for recycling.

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  AtıfScopus2·WoS2

  İncele
• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/12687
  Physical, chemical and thermal characterization of bacterial nanocellulose produced using sugar beet molasses by Komagataeibacter sp. SB2569

  Kara, Adem; Bayram, Sinan

  Bacterial nanocellulose (BNC) is a biopolymer synthesized by bacteria utilizing various carbon sources. The biocompatible and biodegradable nature of BNC offers considerable advantages for its application in fields such as medicine, biomedical engineering, cosmetics, food, nanocomposites, and organoelectronics. Nevertheless, the high production costs necessitate the development of more cost-effective and efficient BNC production methodologies. This study aimed to produce BNC utilizing cost-effective sugar beet molasses. To achieve this, bacteria isolated from various vinegar samples were assessed, revealing that the BNC production potential of these isolates ranged from 2.09 to 3.21 g L⁻1. The 16S rDNA gene of the strain with the highest BNC yield was amplified and sequenced, and it was subsequently deposited in the GenBank database as Komagataeibacter sp. SB2569, with the accession number PV231799.1. XRD analysis revealed characteristic diffraction peaks at 14.8°, 16.5°, 22.6°, and 34.5°, confirming the cellulose 1β crystalline structure and high crystallinity of the synthesized BNC. FTIR analysis exhibited characteristic absorption bandsthat, confirming the presence of β-1,4-glycosidic linkages and the cellulose I structure of BNC. TGA analysis showed an initial weight loss of ~ 5% between 0–100 °C, a major degradation of ~ 75% occurring at 220–350 °C with a maximum decomposition rate at 343 °C, and a residual mass of approximately 10–20% remaining above 600 °C. The findings indicate that the Komagataeibacter sp. SB2569 strain holds significant potential for BNC production using low-cost carbon sources.

  AtıfScopus1·WoS1·OpenAlex2

  İncele
• MakaleYalnız künye2026Scopus SJRQ1/r/bayburt/11559
  Multidimensional characterization of graphite anode degradation in used lithium-ion batteries under real-life conditions

  Temur, Hakan; Kara, Adem

  The degradation of graphite anodes in lithium-ion batteries remains a critical barrier to extending cycle life and enabling efficient recycling. This study employs a multi-technique approach combining XRD, FTIR, SEM-EDS, ICP-MS, and XPS to investigate degradation mechanisms in graphite anodes recovered from commercial spent mobile phone batteries. While unused reference anodes show no significant degradation, spent anodes exhibit surface cracks, porous networks, heterogeneous SEI growth, and pronounced oxygen/fluorine accumulation. FTIR and XRD confirm increased LiF and Li2CO3 formation, indicating electrolyte decomposition and structural breakdown. ICP-MS reveals transition metal migration (Co, Ni, Mn) and current collector corrosion (Cu, Al), which correlate with degradation severity. Surface-sensitive XPS analysis further resolves a progressive degradation pathway: from limited SEI formation in low-degradation samples, through concurrent corrosion and metal crossover in medium-degradation samples, to extensive LiF-rich SEI accumulation in the most degraded samples. These findings are consistent with a self-accelerating chain-reaction mechanism wherein electrolyte decomposition, metal migration, and corrosion synergistically accelerate capacity fade. This study proposes a mechanistic framework for understanding heterogeneous degradation in real-world spent batteries and offers a practical, multi-technique diagnostic tool for recycling and second-life applications.

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  İncele
• MakaleYalnız künye2026Scopus SJRQ2/r/bayburt/11177
  Effects of Graphite Incorporation and Annealing on the Structural, Tribological, and Functional Properties of Electroless Ni-B Coatings

  Bülbül, Ferhat; Kara, Adem; Bülbül, Leman Elif; Güneş, Kübra

  This study explores the synergistic effects of graphite nanoparticles (0.1 wt.%) and thermal annealing (100–600°C) on electroless Ni-B coatings for AISI 4140 steel. Graphite-enabled multifunctional performance—crystallization control, friction reduction, and antibacterial activity—are unlike conventional Ni-B systems. XRD showed amorphous-to-crystalline (Ni3B/Ni2B) transformation, with graphite acting as a nucleation agent below 300°C before degrading at 600°C. The 300°C-annealed composite achieved optimal properties: 0.2 friction coefficient (75% lower than uncoated steel), 60% higher wear resistance, and hardness of 777 HV (+ 3.6% over as-deposited), attributed to graphite lubrication and nanocrystalline Ni3B formation. Antibacterial tests revealed a 3.4-mm inhibition zone against E. coli, though efficacy declined at higher temperatures due to graphite oxidation. All composites maintained superhydrophilicity (contact angle ≈ 0°) without mechanical compromise. By correlating annealing temperature with microstructure, this work provides a design framework for Ni-B/graphite coatings combining low friction (μ = 0.2), high hardness (785 HV), and antibacterial functionality—addressing critical needs for wear-resistant, hygienic surfaces in biomedical and industrial applications.

  AtıfScopus1·WoS1

  İncele
• MakaleAçık Erişim2024Scopus SJRQ3/r/bayburt/13047
  Multifunctional electroless nickel boron composite coatings incorporated by magnesium diboride ceramic particles

  Bülbül, Ferhat; Kara, Adem

  In this study, the role of MgB2 in composite coatings is pivotal. Electroless Ni–B plating, a current-free chemical reduction process, deposits nickel–boron coatings. Other than MgB2, reinforcements like SiC, B4C, and so forth are used with Ni–B coatings for improved properties. The research focuses on Ni–B/MgB2 coatings on AISI 4140 steel using electroless deposition and annealing at different temperatures. Initially, the coating appears dense and amorphous, transforming into worm-like structures through crystallization with MgB2. Higher annealing temperatures lead to brush-like, feathery, and oyster mushroom structures, forming crystalline nickel boron compounds and oxide phases due to synergy. Interestingly, the newly introduced phases disrupt friction patterns nonlinearly, which is linked to MgB2’s ceramic nature and reinforcement quantity. Conversely, incorporating MgB2 and annealing-induced intermetallic phases notably enhances hardness (up to 6) and improves hydrophilicity and antibacterial traits in the coating.

  AtıfScopus6·WoS4·OpenAlex4

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