Deciphering the Influence of Anionic Electrons of Surface-Functionalized Two-Dimensional Electrides in Lithium–Sulfur Batteries

Abstract

Using transition metal compounds as sulfur hosts is regarded as a promising approach to suppress the polysulfide shuttle and accelerate redox kinetics for lithium–sulfur (Li–S) batteries. Herein, we report that a new kind of compound, electrides (exotic ionic crystalline materials in which electrons serve as anions), is efficient sulfur hosts for Li–S batteries for the first time. Based on the first-principles calculations, we found that two-dimensional (2D) electrides M2C (M = Sc, Y) exhibit unprecedentedly strong binding strength toward sulfur species and surface functionalization is necessary to passivate their activity. The 2D electrides modified with the F-functional group exhibit the best performance in terms of the adsorption energy and sulfur reduction process. A comparative study with a nonelectride reveals that the anionic electrons (AEs) of electrides aid in anchoring the soluble polysulfides. These results open an avenue for the application of electrides in Li–S batteries.

Co/Mon Invigorated Bilateral Kinetics Modulation for Advanced Lithium–Sulfur Batteries

“…To further probe the mechanism of the Co/MoN catalyst for the improved LiPSs conversion kinetics, the Gibbs free energy (ΔG) of key reaction products was calculated (Figure 6c). [59] The ΔG value (1.35 eV) of Co/MoN is lower than that of individual Co (1.87 eV) or MoN (2.47 eV) for the reduction of Li 2 S 2 to Li 2 S. Compared with MoN, the relatively smaller Gibbs free energy of Co demonstrates its outstanding catalytic effect. [60] The above calculation results prove that the synergistic effect between Co and MoN has low energy level of ΔG value and is favorable for high cycling battery performance.…”

Predicted superconductivity in one-dimensional A3Hf2B3-type electrides

“…9 This distinctive structure confers upon electrides exceptional electron mobility, low work function, and robust electron-donating capacity, rendering them highly attractive for deployment in various areas, such as superconductivity, [10][11][12] as well as ferromagnetism, [13][14][15] catalysis, [16][17][18] and battery electrodes. [19][20][21] The exploration and development of novel electrides are still ongoing and of great interest. [22][23][24][25] Based on the distribution of anionic electrons, electrides can be categorized into zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D).…”