Tannic acid tuned metal-organic framework as a high-efficiency chemical anchor of polysulfide for lithium-sulfur batteries. (10th August 2018)

• Record Type: Journal Article
• Authors: Ge, Xiaoli; Li, Caixia; Li, Zhaoqiang; Yin, Longwei
• Is Part Of: Electrochimica acta. Volume 281(2018)
• Page Start: 700
• Page End: 709
• Publication Date: 2018-08-10
• Subjects: Metal organic framework -- Hierarchical porous structure -- Li-S battery -- Surface functionalization -- Chemical immobilizing effect; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.06.010
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Despite of great progress in lithium-sulfur (Li-S) batteries, shuttle effect caused by long chain polysulfides, as one of the most serious obstacles, needs to be urgently solved for potentially commercial application of Li-S batteries. Herein, we report on an effective strategy to tune surface functional groups and porous structure of Metal Organic Frameworks (MOFs) to efficiently anchor polysulfides for high-performance Li-S batteries. Tannic acid (TA) tuned Zeolitic Imidazolate Framework-67 (ZIF-67) could create uniformly polar sites for in-situ polysulfide absorption, and C-S and Co-S abundantly functional groups for chemically trapping polysulfides for achieving stable cycling performance. Furthermore, TA tuned ZIF-67 polyhedrons can be sculptured to a core/shell hierarchical porous structure. Foremost, the functionalized polar hydroxyl groups can undergo redox reaction with long polysulfides to form thiosulfate and short insoluble polysulfides, relieving the shuttle effect. ZIF-67-5-S cathode exhibits superior cycling stability and rate capability, showing a steady capacity of at 521 mAh/g after 550 cycles under a current density of 500 mA/g, still maintaining a capacity of 510 mAh/g even at a current density of 1600 mAh/g. The TA polymer etching MOFs route to tune core-shell hierarchically pores and abundantly functional groups offers a potential use in high energy Li-S batteries. Graphical abstract: Image 1