Properties of S-Functionalized Nitrogen-Based MXene (Ti2NS2) as a Hosting Material for Lithium-Sulfur Batteries.

Chenghao Yao,Jinze Li,Kang Duan,Gang Bai,Wei Li,Qingyin Ren,Chen Zhu

doi:10.3390/nano11102478

Abstract

Lithium-sulfur (Li-S) batteries have received extensive attention due to their high theoretical specific capacity and theoretical energy density. However, their commercialization is hindered by the shuttle effect caused by the dissolution of lithium polysulfide. To solve this problem, a method is proposed to improve the performance of Li-S batteries using Ti2N(Ti2NS2) with S-functional groups as the sulfur cathode host material. The calculation results show that due to the mutual attraction between Li and S atoms, Ti2NS2 has the moderate adsorption energies for Li2Sx species, which is more advantageous than Ti2NO2 and can effectively inhibit the shuttle effect. Therefore, Ti2NS2 is a potential cathode host material, which is helpful to improve the performance of Li-S batteries. This work provides a reference for the design of high-performance sulfur cathode materials.

Highlights

The continuous development of electric vehicles and electronic devices puts more requirements on rechargeable batteries [1]
The performance of S-functionalized Ti2N (Ti2NS2) as the host materials for the cathodes of Li-S batteries is studied through first-principles calculations
The performance of S-functionalized Ti2 N (Ti2 NS2 ) as the host materials for the cathodes of Li-S batteries is studied through first-principles calculations

Summary

Introduction

The continuous development of electric vehicles and electronic devices puts more requirements on rechargeable batteries [1]. The technology of lithium batteries is relatively mature, but the low theoretical capacity of them cannot meet the needs of future development [2]. In the process of charging and discharging, the long-chain soluble polysulfides (Li2 S8 , Li2 S6 , Li2 S4 ) produced at the cathode of Li-S batteries are dissolved in the electrolyte. These soluble lithium polysulfides (LiPSs) can shuttle with the electrolyte to the anode (“shuttle effect”), causing the loss of cathode active materials.

Methods

Results

Conclusion