Ultra-Stable Lithium-Sulfur Batteries Using Nickel Phosphide@Carbon Fabric Interlayer

Abstract

Lithium-sulfur batteries (LSB) are highly promising candidates for next generation energy storage devices due to their high theoretical capacity and the low cost of sulfur. However, dissolution of lithium polysulfides (LPS) into electrolyte causes undesirable effects, resulting in loss of active materials, low Coulombic efficiency, and fast capacity fading. To address these issues, designed interlayers are inserted between a separator and S cathode to evaluate the effect of blocking of long chain LPS and catalytic conversion of LPS to Li2S2/Li2S on battery performance. In order to amplify the effect of interlayer, the Ni2P nanoparticles are electrochemically deposited on carbon fabric (CF) which exhibit excellent adsorption and conversion effect of LPS. A cell fabricated with the Ni2P@CF interlayer allows remarkable improvement in the capacity decay of 0.04% per cycle at 1C for 1000 cycles and outstanding high rate capability. The cell delivered a capacity retention of 64% employing a current density of 8 C.