Date of Award
2024
Degree Type
Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
Department
Chemical Engineering
First Advisor
Arijit Bose
Abstract
Lithium-ion batteries have been used in energy storage applications including aviation, transportation, portable electronic devices, and more for decades. Magnesium batteries are being explored as an alternative to lithium-ion batteries because magnesium is more abundant, offers improved safety features, and has a higher volumetric capacity (3833 mAh/cm³ compared to lithium’s 2061 mAh/cm³). Despite these benefits, magnesium batteries do face some challenges. Magnesium exhibits sluggish diffusion during cycling, caused by the reduced mobility of magnesium ions. It is also challenging to find cathodes compatible with magnesium battery systems and many compatible cathodes experience low capacities and working potentials. Many proposed magnesium battery cathodes, such as metal oxides and sulfides, exhibit strong interactions with magnesium due to the localized electrons on the anion groups, which interact with the positively charged magnesium ions and hinder their diffusion. One potential solution to these challenges is the use of carbon cathodes in magnesium batteries. Fullerene is a carbon allotrope with covalently bonded carbon atoms forming a spherical cage-like structure with relatively even charge distribution across the molecule. Due to its unique structure, fullerene can delocalize charges throughout the entire molecule, potentially alleviating the strong charge interactions that hinder other magnesium battery cathode materials. Magnesium batteries with fullerene cathodes have the potential to have improved energy densities and diffusion rates which can enhance cycling capabilities. This work aims to fabricate optimized fullerene cathodes and implement them in magnesium batteries.
The battery components are characterized, and the full cell synthesis process is described. Cell cycling analysis through galvanostatic charge and discharge shows the fullerene cathode is compatible with magnesium batteries. Specific capacities of 34 mAh/g are achieved and redox potentials can be observed from the voltage-capacity data of the cells. The poor capacity retention of the magnesium batteries was explored, and it was found that the fullerene cathode dissolves through the electrolyte, reducing the available active material for electrochemical reactions during cycling and creating pathways for electron transfer between the electrodes. Potential solutions to the cathode dissolution are suggested.
Recommended Citation
Rainone, Lauren, "THE DEVELOPMEMT OF RECHARGEABLE MAGNESIUM BATTERIES WITH CARBON BASED CATHODE MATERIALS" (2024). Open Access Master's Theses. Paper 2569.
https://digitalcommons.uri.edu/theses/2569