Dy katkılanmış Li-iyon pillerde pil performanslarının araştırılması
Yükleniyor...
Dosyalar
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu tez çalışmasında, Co iyonları yerine Dy ile modifiye edilen tabakalı yapıdaki LiCoO2 katot malzemelerinin yapısal, manyetik ve elektrokimyasal özellikleri incelenmiştir. Çalışmalar boyunca LiCo1-xDyxO2 (x=0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.5, 1) katı hal reaksiyon tekniği ile başarılı bir şekilde üretilmiştir. Örneklerin yapısal özellikleri XRD, FTIR, Raman ve XAS ölçümleri kullanılarak analiz edilmiştir. Örneklerin örgü parametreleri açık kaynak kodlu Fullprof programı ile hesaplanmış ve birim hücre hacminin yapıdaki Dy miktarının artışı ile arttığı hesaplanmıştır. Örneklerin bağ yapısı ve Raman aktif modları Dy katkılı örneklerde araştırılmıştır. Örneklerin Co K-kenarı spektrumları ölçülmüş ve XANES ve EXAFS verileri incelenmiştir. Açık kaynak kodlu Athena programı ile örneklerin lokal yapısı belirlenmiştir. Katot malzemesi olarak Dy ile modifiye edilmiş LiCoO2 kullanılarak hücrelerin elektrokimyasal özellikleri ve pil performansları Cr2032 buton piller kullanılarak incelenmiştir. Örneklerin CV grafiklerinde anodik ve katodik pikler vardır ve galvanostatik testler 100 döngüye kadar incelenmiştir. Aynı zamanda oda sıcaklığında C-oranı performansları ölçülmüştür. x=0.04 katkılı örneğin pil performansı saf pile göre daha iyi kapasite ve kapasite azalma oranı gösterdiği bulunmuştur. Bu sonuç ticari olarak ümit vadeden bir durumdur. Pillerdeki kapasite azalma oranı ex-situ olarak FTIR, Raman, XRD ve XAS ölçümleri ile incelenmiş ve Dy katkılamasının pil hücre performansını artırmasının yapısal kararlılık ile ilişkili olduğu bulunmuştur.
In this thesis, structural, magnetic and electrochemical properties of LiCoO2 cathode materials in layered structure modified with Dy instead of Co ions were investigated. During the study, LiCo1-xDyxO2 where x=0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.5, 1 were successfully fabricated by conventional solid state reaction technique. Structural properties of the fabricated samples were analyzed using XRD, FTIR, Raman and XAS measurements. The lattice parameters were calculated using Fullprof open source program and it is found that the lattice volume increases by increasing Dy content in the structure. The bond structure and Raman active modes of samples were investigated in Dy doped samples. Co K-edge spectra of the samples were measured and the XANES and EXAFS data were examined. The local structure of the samples was determined with the Athena open source program. Cr2032 coin cells were used for the investigation of the electrochemical properties and battery performance of the cells using Dy modified LiCoO2 as a cathode material. There are anodic and cathodic peaks in the CV charts of the samples and galvanostatic tests have been examined for up to 100 cycles. The C-rate performance of the cells was also measured at room temperature. It was found that the battery performance of the sample of x=0.04 exhibit better capacity and capacity fade value when compared pure LiCoO2 which is a promising result for commercial battery fabrication. The capacity fade mechanism was also investigated by using ex-situ FTIR, RAMAN, XRD and XAS measurement and it is found that improvement of the cycling performance of the cells with the addition of Dy was related the structural stability.
In this thesis, structural, magnetic and electrochemical properties of LiCoO2 cathode materials in layered structure modified with Dy instead of Co ions were investigated. During the study, LiCo1-xDyxO2 where x=0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.5, 1 were successfully fabricated by conventional solid state reaction technique. Structural properties of the fabricated samples were analyzed using XRD, FTIR, Raman and XAS measurements. The lattice parameters were calculated using Fullprof open source program and it is found that the lattice volume increases by increasing Dy content in the structure. The bond structure and Raman active modes of samples were investigated in Dy doped samples. Co K-edge spectra of the samples were measured and the XANES and EXAFS data were examined. The local structure of the samples was determined with the Athena open source program. Cr2032 coin cells were used for the investigation of the electrochemical properties and battery performance of the cells using Dy modified LiCoO2 as a cathode material. There are anodic and cathodic peaks in the CV charts of the samples and galvanostatic tests have been examined for up to 100 cycles. The C-rate performance of the cells was also measured at room temperature. It was found that the battery performance of the sample of x=0.04 exhibit better capacity and capacity fade value when compared pure LiCoO2 which is a promising result for commercial battery fabrication. The capacity fade mechanism was also investigated by using ex-situ FTIR, RAMAN, XRD and XAS measurement and it is found that improvement of the cycling performance of the cells with the addition of Dy was related the structural stability.
Açıklama
Anahtar Kelimeler
Fizik ve Fizik Mühendisliği, Physics and Physics Engineering
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Altundağ, S. (2020). Dy katkılanmış Li-iyon pillerde pil performanslarının araştırılması. Yayınlanmış Yüksek Lisans Tezi, İnönü Üniversitesi.
