Abstract

Rechargeable lithium-ion batteries are considered as primitive energy storage devices for stationary and mobile application. Rechargeable lithium-ion batteries consist of an intercalation-based cathode (such as lithium cobalt oxide) and an intercalation-based anode (such as graphite). The intercalation chemistry in lithium-ion batteries limits their gravimetric energy density. In contrast, conversion-based redox materials could store much higher energy per unit weight and thus offer a higher gravimetric energy density. Lithium-sulfur batteries contain lithium metal as anode, sulfur as cathode and a polymer separator soaked with an ether-based liquid electrolyte. Following a conversion reaction pathway, each sulfur atom can store two Li atoms which helps lithium-sulfur batteries to produce an extremely high energy density. Theoretically, lithium-sulfur batteries can store five times higher energy density (~ 2600 W h kg–1) in comparison to commercial lithium-ion batteries (~ 500 W h kg–1). However, lithium-sulfur batteries are plagued with fundamental problem of rapid dissolution of lithium-polysulfide intermediates into the liquid electrolyte from the cathode, which causes inferior cycling stability. My research focuses on development of meal oxide/sulfur composite cathode to overcome the above-mentioned issue. Metal oxides, being polar materials, could immobilize the lithium-polysulfide intermediates through strong chemical interaction and thus control their rapid dissolution into the liquid electrolyte. Several characterization techniques such as in-situ Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and so on are employed to understand the chemical interaction between different metal oxides and the intermediate lithium-polysulfides.

Bio

Mr. Arnab Ghosh is currently pursuing his PhD degree in IITB-Monash Research Academy. His doctoral dissertation was conducted in consultation with Prof. Sagar Mitra (IITB), Prof. Douglas MacFarlane (Monash University) and Dr. Mega Kar (Monash University). Arnab did his B.Sc. in Chemistry from The University of Burdwan, West Bengal and M.Sc. (Chemistry) from Indian Institute of Technology Hyderabad, India.