Scalable Synthesis of Ultrathin Polyimide Covalent Organic Framework Nanosheets for High-Performance Lithium-Sulfur Batteries.
J Am Chem Soc
; 143(46): 19446-19453, 2021 Nov 24.
Article
em En
| MEDLINE
| ID: mdl-34731564
ABSTRACT
Development of new porous materials as hosts to suppress the dissolution and shuttle of lithium polysulfides is beneficial for constructing highly efficient lithium-sulfur batteries (LSBs). Although 2D covalent organic frameworks (COFs) as host materials exhibit promising potential for LSBs, their performance is still not satisfactory. Herein, we develop polyimide COFs (PI-COF) with a well-defined lamellar structure, which can be exfoliated into ultrathin (â¼1.2 nm) 2D polyimide nanosheets (PI-CONs) with a large size (â¼6 µm) and large quantity (40 mg/batch). Explored as new sulfur host materials for LSBs, PI-COF and PI-CONs deliver high capacities (1330 and 1205 mA h g-1 at 0.1 C, respectively), excellent rate capabilities (620 and 503 mA h g-1 at 4 C, respectively), and superior cycling stability (96% capacity retention at 0.2 C for PI-CONs) by virtue of the synergy of robust conjugated porous frameworks and strong oxygen-lithium interactions, surpassing the vast majority of organic/polymeric lithium-sulfur battery cathodes ever reported. Our finding demonstrates that ultrathin 2D COF nanosheets with carbonyl groups could be promising host materials for LSBs with excellent electrochemical performance.
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MEDLINE
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En
Revista:
J Am Chem Soc
Ano de publicação:
2021
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Article