Affiliation:
1. International Joint Research Center for Advanced Energy Materials of Yunnan Province Yunnan Key Laboratory of Carbon Neutrality and Green Low‐carbon Technologies School of Materials and Energy Yunnan University Kunming 650091 China
2. Department of Advanced Materials Southwest United Graduate School Kunming 650091 China
Abstract
AbstractLithium–sulfur (Li–S) batteries stand out for their high theoretical specific capacity and cost‐effectiveness. However, the practical implementation of Li–S batteries is hindered by issues such as the shuttle effect, tardy redox kinetics, and dendrite growth. Herein, an appealingly designed covalent organic framework (COF) with bi‐functional active sites of cyanide groups and polysulfide chains (COF‐CN‐S) is developed as cooperative functional promoters to simultaneously address dendrites and shuttle effect issues. Combining in situ techniques and theoretical calculations, it can be demonstrated that the unique chemical architecture of COF‐CN‐S is capable of performing the following functions: 1) The COF‐CN‐S delivers significantly enhanced Li+ transport capability due to abundant ion‐hopping sites (cyano‐groups); 2) it functions as a selective ion sieve by regulating the dynamic behavior of polysulfide anions and Li+, thus inhibiting shuttle effect and dendrite growth; 3) by acting as a redox mediator, the COF‐CN‐S can effectively control the electrochemical behavior of polysulfides and enhance their conversion kinetics. Based on the above advantages, the COF‐CN‐S endows Li–S batteries with excellent performance. This study highlights the significance of interface modification and offers novel insights into the rational design of organic materials in the Li–S realm.
Funder
National Natural Science Foundation of China
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science
Cited by
1 articles.
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