High power 4.7 V nanostructured spinel lithium manganese nickel oxide lithium-ion battery cathode materials
Başlık çevirisi mevcut değil.
- Tez No: 402667
- Danışmanlar: PROF. GLENN G. AMATUCCI
- Tez Türü: Doktora
- Konular: Kimya, Metalurji Mühendisliği, Chemistry, Metallurgical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2007
- Dil: İngilizce
- Üniversite: Rutgers, The State University of New Jersey-New Brunswick Campus
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 174
Özet
Özet yok.
Özet (Çeviri)
Nanostructured LiMni.5+gNio.5-s0 4 spinel powders were synthesized by a solution based chemistry method called modified Pechini. The impacts of processing parameters such as synthesis temperature, oxygen-partial-pressure and mole ratio of ethylene glycol to citric acid on the morphology, structure and properties of spinel materials have been studied thoroughly via various in-situ and ex-situ characterization techniques. Later, these parameters were tied with the electrochemical properties of spinel electrodes. After optimization of processing steps and glycol/acid ratio, a unique mesoporous morphology with interconnected nanoparticles were successfully obtained. Such morphology was found to be very conducive to achieve high power density lithium-ion battery spinel cathodes. This was attributed to (i) large number of mesoporosities that favor electrolyte penetration, thereby enabling better wetting of spinel cathodes and faster lithium ion transfer at electrolyte/cathode interface and (ii) particle interconnectivity that allows continuous electron transport, which becomes highly critical especially at high current rates. The synthesis temperature and oxygen-partial-pressure were found to affect the structure significantly. Depending on the ordering/disordering of transition metal ions on octahedral sites, spinels were assigned to either ordered P4332 or disordered Fd3m space groups. The spinel of the two symmetry groups differed significantly in fast discharge rate capability. In an effort to identify the origin of this electrochemical disparity, intensive characterizations of both structures were undertaken (in-situ: XRD, Impedance spectroscopy, Raman; ex-situ\ XRD, FTIR, TGA, electronic conductivity and lithium diffusivity and more). The poor performance of the ordered phase was attributed to its intrinsic properties, namely lower electronic conductivity and lithium diffusion coefficient (DlO- Regarding the former, the mechanism of electron conduction in LiMni.5 +sNio.5-s0 4 was demonstrated to be electron hopping from Mn3+ (non existent in P4332 when 5=0.5) to Mn4+ sites. The difference between highest electronic conductivity spinel (Fd3m phase) and lowest conductivity spinel (P4332 phase) was measured to be as much as 2.5 orders-of-magnitude. As for the latter, the disordered spinel was found to have an order-of-magnitude higher E>Li than its ordered counterpart for the same composition. Finally, elevated temperature performance of spinel electrodes was studied. A plausible scenario for the failure mechanism of battery cells was suggested.
Benzer Tezler
- Bimodal fonksiyonel dokusuz hava filtrelerinin üretimi ve geçirgenlik özelliklerinin karakterizasyonu
Production of bimodal functional non-woven air filters and characterization of their permeability properties
ALİ TOPTAŞ
Doktora
Türkçe
2023
Tekstil ve Tekstil Mühendisliğiİstanbul Teknik ÜniversitesiTekstil Mühendisliği Ana Bilim Dalı
DOÇ. DR. ALİ KILIÇ
- Yüksek güç verimli biyouyumlu enerji depolama sistemleri için ince film üretimi
Thin film production and applications in solar cell systems for high power efficiency
SİBEL YAZAR AYDOĞAN
Doktora
Türkçe
2020
Biyoteknolojiİstanbul Üniversitesi-CerrahpaşaKimya Ana Bilim Dalı
PROF. DR. GÜLTEN ATUN
- Investigating the influence of pH on the transport characteristics of the silicon carbide nanowires-based field-effect transistors for environmental sensing
Çevresel algılama için silikon karbür nanotel bazlı alan etkisi transistörlerinin taşınım özellikleri üzerinde pH'ın etkisinin incelenmesi
MUHAMMAD AWAIS
Yüksek Lisans
İngilizce
2021
Elektrik ve Elektronik MühendisliğiMarmara ÜniversitesiElektrik ve Elektronik Mühendisliği Ana Bilim Dalı
PROF. DR. KAŞİF TEKER
- Investigation of the growth kinetics and morphology transitions during porous anodization of titanium in ethylene glycol based electrolytes
Etilen glikol bazlı elektrolitlerde titanyumun gözenekli anodizasyonu sırasında oluşan oksidin büyüme kinetiği ve morfolojik geçişlerinin incelenmesi
EREN SEÇKİN
Doktora
İngilizce
2022
Metalurji Mühendisliğiİstanbul Teknik ÜniversitesiMalzeme Bilimi ve Mühendisliği Ana Bilim Dalı
PROF. DR. MUSTAFA KAMİL ÜRGEN
- Elektrodöndürme yöntemiyle elde edilen jelatin nanoliflerinin emülsiyonlarda stabilize edici olarak kullanılması
Using electrospun gelatin nanofibers as stabilizers in emulsions
NAGİHAN OKUTAN
Yüksek Lisans
Türkçe
2013
Gıda Mühendisliğiİstanbul Teknik ÜniversitesiGıda Mühendisliği Ana Bilim Dalı
YRD. DOÇ. DR. FİLİZ ALTAY