Optimising Sulphur Phase Transitions and Interface Dynamics for Advanced Lithium-Sulfur Batteries in Ionic Liquid Electrolytes

Background

;The availability of sulfur as a cathode material1 and the high theoretical energy density of lithium-sulfur (Li-S) batteries2 make them one of the most intriguing options for next-generation energy storage systems. Li-S batteries are perfect for uses like grid energy storage and electric cars because of their characteristics.3 Their economic feasibility is hampered by issues such lithium metal instability4, the shuttle effect5, electrode deterioration6, and polysulphide dissolution7. Ionic liquid (IL) electrolytes can successfully address these issues by stabilising the electrode contact, inhibiting polysulphide dissolving, and improving overall battery performance, as my latest research has shown.

;Research-gap

;Although the promise of IL-based electrolytes is shown by my initial study, there are still important information gaps.8,9 It is still unclear how the sulfur-electrolyte interface changes throughout cycling and how sulphur phase transitions during lithiation and delithiation are controlled. Additionally, the design of the sulphur electrode has not been improved to enhance the special qualities of IL electrolytes. To advance Li-S battery technology and realise its full potential, these gaps must be filled.

;Aim

;To enhance the performance and lifetime of lithium-sulfur batteries, it is necessary to look into the mechanisms underlying sulphur phase transitions, analyse the dynamic evolution of the sulfur-electrolyte interface, and redesign the sulphur electrode for best compatibility with ionic liquid-based electrolytes.

;Objectives

;1. Examine sulfur phase transitions: Describe the structural and chemical changes that sulphur undergoes in IL-based electrolytes during lithiation and delithiation.;

2. Analyze interface dynamics: Examine how the sulfur-electrolyte interface varies throughout cycling, paying particular attention to the development of passivation layers and how they affect electrochemical performance.;

3. Redesign the sulfur electrode: To increase compatibility and efficiency, create and assess sulfur electrode designs tailored for ionic liquid electrolytes.;

4. Optimize IL electrolytes: Adjust IL compositions to improve interface stability, reduce polysulphide dissolution, and allow for excellent cycling performance.;Significance;

By removing important obstacles at the sulfur-electrolyte interface and improving the sulfur electrode for ionic liquid electrolytes, this initiative seeks to revolutionize Li-S battery architecture. This effort will provide the groundwork for creating Li-S batteries that are effective, long-lasting, and scalable by using knowledge of phase transitions and interfacial dynamics. The results will accelerate the use of Li-S batteries in environmentally friendly energy storage technologies and have a major impact on their commercialization.;

References;

1. A. Kumar, et al. ACS Energy Lett. 2020, 5, 6, 2112–2121. 2. A. Kumar, et al. Energy Storage Materials, 2019, 20, 196-202. 3. A. Kumar, et al. ACS Appl. Energy Mater. 2021, 4,1,384-393. 4. A. Ghosh, A. Kumar, et al. (2021) App. Mat. Today 23: 101062. 5. A. Kumar, et al. Energy Storage Materials, 2021, 42, 608-617. 6. A. Kumar, et al. ACS applied materials & interfaces, 2019, 11 (15), 14101-14109. 7. A. Kumar, et al. Adv. Funct. Mater. 11th Sep 2020. 8. A. Kumar, et. al. Int. Patent. AU2024900718. 9. A. Kumar, et. al. Int. Patent. AU2024900719. ;