Physics

Dr. Nikhil Koratkar
Rensselaer Polytechnic Institute, New York, USA

ABSTRACT

Lithium-sulfur (Li-S) batteries offer a theoretical energy density of ~2600 Wh/kg (compared to ~387 Wh/kg for Li-ion technology) and therefore offer great potential as a next generation energy storage device. However there are two major barriers to realization of high performance Li-S batteries: (1) poor cycle stability caused by dissolution of intermediate lithium polysulfides from the S cathode into the electrolyte and (2) nucleation and growth of dendritic structures on the Li metal anode, which can electrically short the battery. In this talk,
I will discuss some possible solutions to these problems. Specifically, I will show that two-dimensional (2D) sheets of black phosphorous (i.e. phosphorene) are highly effective as a lithium polysulfide trapping agent. I will further show that the Li dendrite problem can be addressed by using self (Joule) heating to accelerate surface diffusion processes to heal (smoothen) the dendrites in situ. Such advances show potential in enabling the successfully deployment of Li-S batteries with breakthrough improvements in performance as compared to the incumbent Li-ion technology.