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Scalable Synthesis of Ultrathin Polyimide Covalent Organic Framework Nanosheets for High-Performance Lithium–Sulfur Batteries
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2021-11-03 , DOI: 10.1021/jacs.1c08675
Haiyan Duan 1, 2, 3 , Ke Li 3, 4 , Mo Xie 1 , Jia-Ming Chen 1 , Hou-Gan Zhou 1 , Xiaofeng Wu 2 , Guo-Hong Ning 1 , Andrew I Cooper 2 , Dan Li 1
Affiliation  

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 (∼1.2 nm) 2D polyimide nanosheets (PI-CONs) with a large size (∼6 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.

中文翻译:

用于高性能锂硫电池的超薄聚酰亚胺共价有机骨架纳米片的可扩展合成

开发新型多孔材料作为主体以抑制多硫化锂的溶解和穿梭,有利于构建高效的锂硫电池(LSB)。尽管二维共价有机框架 (COF) 作为主体材料显示出 LSB 的潜力,但其性能仍不令人满意。在此,我们开发了具有明确层状结构的聚酰亚胺 COF(PI-COF),可将其剥离成超薄(~1.2 nm)二维聚酰亚胺纳米片(PI-CON),具有大尺寸(~6 μm)和大量(40 毫克/批次)。作为 LSB 的新型硫主体材料,PI-COF 和 PI-CON 具有高容量(0.1 C 时分别为1330 和 1205 mA hg –1)、优异的倍率性能(620 和 503 mA hg –1)分别在 4 C)和优异的循环稳定性(PI-CON 在 0.2 C 时容量保持率为 96%),凭借强大的共轭多孔骨架和强氧-锂相互作用的协同作用,超越了绝大多数有机/聚合物锂– 硫电池正极曾经报道过。我们的发现表明,具有羰基的超薄二维 COF 纳米片可能是具有优异电化学性能的 LSB 的有前途的主体材料。
更新日期:2021-11-24
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