(A) study on the cathode design and their electrochemical properties for lithium sulfur batteries

Abstract

Lithium sulfur (Li-S) batteries have attracted significant attention as one of the most promising types of next-generation lithium rechargeable batteries due to their high energy density (~2500 Wh/$kg^{-1}$ sulfur), low cost and environmentally friendly characteristics. However, rapid capacity fading phenomena originated from the generation of various soluble polysulfide $Li_2S_x$ (3 $\leq$ x $\leq$) intermediates is one of major obstacle for the commercialization. Considering the fact that the dissolution of polysulfides in an ether-based electrolyte is unavoidable, development of a novel cathode design for the cell configuration and electrode materials is necessary. In this dissertation, two-type of cell configuration (inserting an interlayer and using 3-dimensional current collector) and two anchoring materials (aluminum oxide and titanium oxide/titanium oxynitride composite) have been proposed for improving the electochemical performance of Li-S cells.