Distributed Li‐Ion Flux Enabled by Sulfonated Covalent Organic Frameworks for High‐Performance Lithium Metal Anodes. Issue 7 (4th January 2023)

• Record Type: Journal Article
• Authors: Han, Diandian; Yang, Xiubei; Li, Kuokuo; Sun, Linhai; Hou, Tian; Zhang, Lin; Sun, Yanyun; Zhai, Lipeng; Mi, Liwei
• Is Part Of: Macromolecular rapid communications. Volume 44:Issue 7(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-04
• Subjects: covalent organic frameworks -- high‐performance Li anodes -- Li‐ion flux -- quasi‐solid‐state electrolytes -- sulfonation; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.202200803
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract: Metallic Li is considered the most promising anode material for high‐energy‐density batteries owing to its high theoretical capacity and low electrochemical potential. However, inhomogeneous lithium deposition and uncontrollable growth of lithium dendrites result in low lithium utilization, rapid capacity fading, and poor cycling performance. Herein, two sulfonated covalent organic frameworks (COFs) with different sulfonated group contents are synthesized as the multifunctional interlayers in lithium metal batteries. The sulfonic acid groups in the pore channels can serve as Li‐anchoring sites that effectively coordinate Li ions. These periodically arranged subunits significantly guide uniform Li‐ion flux distribution, guarantee smooth Li deposition, and reduce lithium dendrite formation. Consequently, these characteristics afford an excellent quasi‐solid‐state electrolyte with a high ionic conductivity of 1.9 × 10 −3 S cm −1 at room temperature and a superior Li ++ transference number of 0.91. A Li/LiFePO4 battery with the COF‐based electrolyte exhibited dendrite‐free Li deposition during the charge process, accompanied by no capacity decay after 100 cycles at 0.1 C. Abstract : Covalent organic frameworks (COFs) with abundant sulfonated groups are synthesized and further employed as the interlayer in the batteries to guide the uniform Li + flux and realize smooth lithium deposition, where the built‐in sulfonate groups act as anchoring sites for strongly attracting Li + and the extended planar porous structure serve as the Li + flux channel. Therefore, Li/LiFePO4 battery with COF‐based interlayer exhibits dendrite‐free Li deposition and a no capacity decay after 100 cycles at 0.1 C.