Disputation: Amund Ruud
MSc Amund Ruud at the Department of Chemistry is defending the thesis: « Novel Materials and Operando Studies for Lithium-Ion Batteries» for the degree of Philosophiae Doctor.
December 5th, 10:15 AM, Auditorium 2, Kjemibygningen
«John B. Goodenough, M. Stanley Whittingham and Akira Yoshino: A Li-ion battery history – materials and mechanisms.»
Litium‑ion batteri har revolusjonert dagens samfunn. Allikevel er arbeid med nye materialer for videre utvikling av denne teknologien viktig. Denne oppgaven har arbeidet med å utvikle slike materialer, samt å studere hvordan strukturen til disse materialene endres under ut‑ og oppladning.
The current thesis deals with the development and detailed investigations of new materials for lithium-ion batteries. A major part of this work has been to investigate the electrochemical performance of two new anode materials; BiVO4 and Bi2(MoO4)3. We have used operando X-ray diffraction and X-ray absorption spectroscopy to identify changes in structure and oxidation state of these materials during charging and discharging. Furthermore, BiVO4 has been investigated operando with pair distribution function analysis computed tomography. This has allowed us to identify several nano phases during battery cycling with sizes of about 1 – 10 nm (Figure 1).
Atomic layer deposition is a supreme technique for deposition of thin film. Utilizing atomic layer deposition to apply protective coatings on battery materials has been reported to improve specific capacity and cycling stability of battery materials. The current work has identified a new lithium precursor. This new precursor has been used to deposit of Li2CO3, LiAlO2 and Li2SiO3, materials with potential application within batteries.
Figure 1: Illustration showing the evolution of the Bi related phases for the first 1.5 cycles of BiVO4.