Rational design of porous carbon allotropes as anchoring materials for lithium sulfur batteries

摘要

The shuttle effect seriously impedes the development and practical application of lithium sulfur(Li-S)batteries.It is still a long-term challenge to find effective anchoring materials to hinder the shuttle effect of Li-S batteries.Using carbon allotrope as anchoring materials is an effective strategy to alleviate the shuttling effect.However,the influence factors of carbon allotrope on the adsorption performance of LIPSS at the atomic level are not clear,which limits the application of carbon allotrope in Li-S batteries.Herein,using first-principles simulations,a systematical calculation of carbon allotropes with various ring size(6 ≤S≤16) and shape is conducted to understand the adsorption mechanism.The results show that the T-G monolayers with suitable ring structure and high charge transfer can significantly enhance the interaction between the monolayer and LiPSs,allowing them to have high capacity and high coulombic efficiency.Further diffusion studies show that LiPSs on the T-G monolayer have the low diffusion barriers,which ensures the charging and discharging rate of batteries.Our studies could provide material design principles of carbon allotrope monolayers used as anchoring materials of the high performance Li-S batteries.