P,O,N-Co Doped Carbon Scaffolds from LiFePO4 Nanoparticles As Sulfur Hosts for Lithium-Sulfur Batteries

Abstract

Lithium-sulfur (Li-S) batteries are well knowned as one of the promising energy applications with high specific capacity, such as electric vehicles and energy storage system, owing to their high theoretical capacity of 1672 mA h g−1, eco friendliness, and the abundance all over the world. However, Li-S batteries have some challenge, such as the poor Coulombic efficiency, fast capacity fading, and unstable cycle performance by the dissolution of lithium polysulfides (LiPSs) in the electrolyte by shuttle mechanism during long cycling. To challenge these problems, we suggest that P, O, and N co-doped hollow carbons with graphene from LiFePO4 nanoparticles are very efficient as sulfur hosts for Li-S batteries. This sample from LiFePO4 nanoparticles provides sufficient spaces with the variety of pore sizes for storage of sulfur and various heteroatoms doping to minimize the dissolution of the LiPSs. This sample can block the dissolution of LiPSs due to the efficient hosts and the excellent chemical affinity with LiPSs. Its electrode indicates the very stable cycle performance and high rate capability, as proved by LiPSs adsorption test. We suggest that this sample has high potential as a sulfur host for real application in Li-S batteries with more optimization.