Surface/Interface Structure and Chemistry of Lithium–Sulfur Batteries: From Density Functional Theory Calculations’ Perspective

Abstract

Nowadays, the rapid development of portable electronic products and low‐emission electric vehicles is putting forward higher requirements for energy‐storage systems. Lithium–sulfur (Li–S) batteries with an ultrahigh energy density (2500 Wh kg−1) are considered the most promising candidates for next‐generation rechargeable batteries. However, the low conductivity of sulfur, the shuttle effect of lithium polysulfide (LPS), and inadequate safety caused by lithium dendrite formation limit their practical applications. In the research of Li–S batteries, it is observed that the surface/interface structure and chemistry of sulfur host materials play significant roles in the performance of Li–S batteries. The reason is that the adsorption/conversion of LPS mainly occurs on the surface/interface of host materials. The functional hosts are used to prevent the polysulfide shuttle or catalyze Li–S conversion reactions (enhance the reaction kinetics), and density functional theory (DFT) is used to understand the mechanism of the interaction between host and polysulfides. Herein, the surface/interface structure and chemistry of sulfur host materials involving structural factors and adsorption/conversion mechanisms of LPS (based on DFT calculation) on the interface are demonstrated. Finally, the remaining challenges, such as the fundamental studies and commercialized applications, as well as the future research directions are discussed.

A review on theoretical models for lithium–sulfur battery cathodes

“…Currently, the LiPSs conversion on the electrocatalysts has been investigated by simulating the reduction reaction from S 8 to Li 2 S. Kong and coworkers calculated the Gibbs free energies of each S reduction pathway to assess the catalytic properties of host materials. 57 The reaction of sulfur reduction is considered as follows: 110,111…”

“…Currently, the LiPSs conversion on the electrocatalysts has been investigated by simulating the reduction reaction from S 8 to Li 2 S. Kong and coworkers calculated the Gibbs free energies of each S reduction pathway to assess the catalytic properties of host materials 57 . The reaction of sulfur reduction is considered as follows: 110,111 where * is the catalyst. Then they calculated the Gibbs free energies of each path for the above reactions.…”

Current Status and Challenges of Calcium Metal Batteries

“…Various graphitic carbon, if the defects, pore and surface, and phase structure are rationally engineered, is another type of promising cathode material, based on an anion-cation relay storage mechanism. [2,[22][23][24][25][26][27] Hence, the future trends in cathode materials lie in not only achieving cycling stability and long lifespan of S and sulfides, [28,29] layered metal oxides, [30] and Current calcium metal batteries and future trends from voltage-capacity-efficiency's view, in which the redox potentials for cathodes and Cametals, as well as some reference electrodes frequently involved in the research of calcium batteries, are calibrated to versus SHE. All the data are adapted from publications reported previously.…”

Perspectives on manufacturing simulations of Li-S battery cathodes

“…Modeling has made important contributions when it comes to understanding the operational principles of LSBs from both, the materials, and mechanistic perspectives. Atomistic and molecular dynamics simulations have focused on understanding the interactions between salts, solvents and PS species [26,27], and on elucidating their interactions with carbon or other conductive supports [28]. Moreover, continuum models of LSBs have been valuable in shedding light on the PS reaction steps and limiting factors of battery cell operation [11,[29][30][31][32].…”