Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of "Branch-Leaf" Electrode for High-Energy Sodium-Sulfur Batteries

• 作者: Wenyan Du Kangqi Shen Yuruo Qi Wei Gao Mengli Tao Guangyuan Du Shu?juan Bao Mingyang Chen Yuming Chen Maowen Xu
• 来源期刊: 纳微快报（英文）
• 年，卷（期）: 2021,（3）
• 页码范围: 155-167
• 页数: 13页
• 语种: 英文

摘要

Rechargeable room temperature sodium-sulfur (RT Na-S) batteries are seriously limited by low sulfur utiliza-tion and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D "branch-leaf" biomimetic design proposed for high performance Na-S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive "branches" to ensure adequate electron and elec-trolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D "branch-leaf" conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemi-cal reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co-S-Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared "branch-leaf" CNF-L@Co/S electrode exhibits a high initial specific capac-ity of 1201 mAh g-1 at 0.1 C and superior rate performance.