Energy storage and life-cycle assessment in lithium air batteries

Since lithium air batteries theoretically have at least 10 times higher energy density than today's best lithium-ion battery technology, the expectation has arisen that they can create a technology that will reduce exhaust emissions in electric vehicles. Although the theoretical capacity of these batteries is high, researches are being carried out to improve the capacity and energy density that can be obtained in practice. The aim of this study is to analyze the environmental effects of lithium-air batteries compared to internal combustion engine vehicles and other battery technologies, and to reveal their advantages and disadvantages. In this thesis study, PVDF polymer and Al2O3, SiO2 nano ceramic particles were added to TEGDME + LiPF6 electrolyte to prevent clogging of air permeable cathode with lithium oxide and to ensure lithium metal anode stability. Graphene / -MnO2 nanocomposite coated on nickel foam was used as air permeable cathode. Glass fiber separator and lithium metal were used as anode in ECC-Air test cells. Cells were tested in a voltage range of 2.15-4.25 V. The results showed that hybrid electrolytes with additions of 1% PVDF and 0.5% Al2O3, 0.5% SiO2 by weight of ceramic nanoparticles increased cell stability, charge-discharge capacity and cycle efficiency. After the electrochemical cycle tests, scanning electron microscopy SEM and Raman analyzes were performed to determine the reaction products of cathode morphologies. Within the scope of the study, it was aimed to examine the production, development of technology and use of Lithium air batteries by performing Life Cycle Assesment (LCA) and to develop and environmentally guide the battery technology. Lithium air cells have been analyzed considering the processes of raw material production, cathode manufacture, cell preparation, battery assembly and use of the battery in an electric vehicle. The common denominator of "environmental impact per 1 km" has been chosen as a functional unit in order to make it easy to compare with internal combustion engine vehicles and other battery technologies. LCA effects were measured in terms of global warming potential, depletion of abiotic resources and human toxicity. It has been determined that the environmental effects of the battery are largely due to the high electrical energy required during cathode production for the battery cell.