Yazar "Gultekin, Sidika Yildirim" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    Enhanced performance of lithium-ion battery anodes using CuO nanorod/ graphene aerogel composites
    (Elsevier Science Sa, 2025) Uzun, Esma; Guler, Mehmet Oguz; Guler, Aslihan; Kuruahmet, Deniz; Gultekin, Sidika Yildirim; Gungor, Hatice; Singil, Mustafa Mahmut
    In this study, CuO nanorods and CuO/graphene aerogel (GA) composites are investigated as potential anode materials. CuO nanorods were synthesized by chemical precipitation, while the CuO/graphene aerogel hybrid was prepared by the aerogel method. Structural, morphological and electrochemical characterizations were performed, which showed enhanced performance of the CuO/GA hybrid composite. This composite structure retained 90 % of its capacitance after 500 cycles, significantly outperforming the pure CuO electrode. The unique properties of CuO's high theoretical capacity combined with graphene's superior conductivity lead to enhanced lithium storage and structural resilience. This study examines CuO nanorods combined with graphene aerogels to leverage graphene exceptional conductivity and 3D porous structure for improved performance.
  • Küçük Resim Yok
    Öğe
    Enhanced performance of lithium-ion battery anodes using CuO nanorod/graphene aerogel composites (vol 155, 112356, 2025)
    (Elsevier Science Sa, 2025) Uzun, Esma; Guler, Mehmet Oguz; Guler, Aslihan; Kuruahmet, Deniz; Gultekin, Sidika Yildirim; Gungor, Hatice; Singil, Mustafa Mahmut
  • Küçük Resim Yok
    Öğe
    Graphene aerogel-supported Na3V2(PO4)3/C cathodes for sodium-ion batteries
    (Elsevier Science Sa, 2023) Gultekin, Sidika Yildirim; Guler, Aslihan; Kuruahmet, Deniz; Gungor, Hatice; Singil, Mustafa Mahmut; Uzun, Esma; Akbulut, Hatem
    Na3V2(PO4)3 (NVP) is a preferred cathode material for Na-ion batteries due to its good thermal stability and long cycle life, but its low electrical conductivity limits its use. The carbon coating method is widely available in the literature but can solve the problem to a limited extent. Graphene aerogel-based composite materials with lightweight, high surface area and 3-dimensional (3D) porous structure are prepared, and the properties are tried to be improved further. In this study, carbon-coated Na3V2(PO4)3 (NVP/C) and graphene aerogel-carbon-coated Na3V2(PO4)3 (GA-NVP/C) composite have been synthesized. The produced samples have been analyzed using Field emission scanning electron microscopy, X-ray diffraction, Raman spectrum, Thermal Gravity Analysis, Xray photoelectron spectroscopy, Brunauer-Emmett-Teller and Transmission electron microscopy. Then, the effect of graphene aerogel additive on electrochemical performances as cathode materials has been investigated. Even though GA-NVP/C and NVP/C have similar discharge capacities in the first cycle, GA-NVP/C shows high cycle stability when compared to NVP/C after 250 cycles. The GA-NVP/C cathode also has a higher discharge capacity than the NVP/C cathode at different current rates. The diffusion coefficient calculated using the cyclic voltammetry curve of GA-NVP/C is also high, supporting the graphene aerogel's positive results. In conclusion, we show that adding GA with a 3-dimensional porous structure greatly improves the electrochemical properties of the cathode in Na-ion batteries.