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A Detailed Study of factors That Enhances the Performance of High-rate Li-Air Batteries
thesis
posted on 2023-05-01, 00:00 authored by Chengji ZhangThe rise in demand for electric transportation is widely acknowledged as a way to decrease reliance on fossil fuels and mitigate the impact of climate change. Among various contenders for advanced energy storage technology, the lithium-air battery has garnered significant attention due to its high theoretical energy density that is comparable to gasoline combustion. This renders it a promising option for powering fully electric vehicles. However, one of the significant challenges in its development is the high overpotential that occurs during the redox reaction between charge and discharge. Additionally, battery cycling results in electrolyte and electrode decomposition, which leads to cathode blockage, thereby reducing energy efficiency and cycle life.
To overcome these challenges, this study introduces various methods, including a new solid-state catalyst and bi-functional electrolyte additives. As a result of these efforts, a significantly improved Li-O2 cell was developed, with a current density of up to 1mA/cm2 (equivalent to 10000mA/g). Furthermore, a Li-Air battery system was reported, and its discharge products were found to be lithium superoxide, as intended, rather than lithium peroxide under high current densities, thereby reducing discharge overpotentials and preventing cathode clogging. Additionally, 20 different RMs were analyzed for their electrochemical properties in the Li-O2 system using DMSO and TEGDME electrolytes through cyclic voltammetry (CV) experiments. The redox potential, cathodic and anodic peak separation, and current intensities were among the measured features. Different characterization techniques, including SEM, TEM, and Raman, were employed to investigate the battery's morphology and redox products, and battery cycling tests were conducted to gain a better understanding of the two-step mechanism of the Li-Oxygen battery system.
History
Advisor
Salehi-Khojin, AminChair
Salehi-Khojin, AminDepartment
Mechanical and Industrial EnginneringDegree Grantor
University of Illinois at ChicagoDegree Level
- Doctoral
Degree name
PhD, Doctor of PhilosophyCommittee Member
Curtiss, Larry A Ngo, Anh T Subramanian, Arunkumar Megaridis, Constantine M Khalili-Araghi, FatemehSubmitted date
May 2023Thesis type
application/pdfLanguage
- en