Song Xiaohan, Qu Yuanyuan, Zhao Lanling, Zhao Mingwen
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
ACS Appl Mater Interfaces. 2021 Mar 17;13(10):11845-11851. doi: 10.1021/acsami.0c21136. Epub 2021 Mar 3.
The high energy density, low cost, and environmental friendliness of lithium-sulfur (Li-S) batteries enable them to be promising next-generation energy storage systems. However, the commercialization of Li-S batteries is presently hindered by the bottlenecks, such as the low conductivity of sulfur species, shuttle effect of polysulfides, and poor conversion efficiency in discharging/charging processes. Here, on the basis of first-principles calculations, we predicted that the two-dimensional magnetic FeGeX (X = S, Se, and Te) monolayers are quite promising to overcome the aforesaid problems. The FeGeX monolayer has metallic electronic structures and moderate binding strength to the soluble lithium polysulfides, which are expected to improve the overall electric conductivity of sulfur species and anchor the soluble lithium polysulfides to suppress the shuttle effect. Remarkably, FeGeX monolayers show bifunctional electrocatalytic activity to the S reduction reaction and the LiS decomposition reaction, which improves the conversion efficiency in discharging and charging processes. This finding may open up an avenue for the development of high-performance Li-S batteries.
锂硫（Li-S）电池的高能量密度、低成本和环境友好性使其成为很有前景的下一代储能系统。然而，目前Li-S电池的商业化受到硫物种电导率低、多硫化物穿梭效应以及充放电过程中转换效率低等瓶颈的阻碍。在此，基于第一性原理计算，我们预测二维磁性FeGeX（X = S、Se和Te）单层在克服上述问题方面很有前景。FeGeX单层具有金属电子结构，并且对可溶性锂多硫化物具有适度的结合强度，这有望提高硫物种的整体电导率并锚定可溶性锂多硫化物以抑制穿梭效应。值得注意的是，FeGeX单层对S还原反应和LiS分解反应具有双功能电催化活性，这提高了充放电过程中的转换效率。这一发现可能为高性能Li-S电池的开发开辟一条途径。
